Recent ucsdsom_rad_oapdeposits items

Imaging congenital anomalies of the ileum in adults:a pictorial review

Thu, 18 Jun 2026 00:00:00 +0000

The ileal loops are anatomical location for the majority of congenital anomalies affecting the gastrointestinal tract. These include Meckel’s diverticulum, ileal duplication, dysgenesis, atresia, mucosal diaphragm, and malposition of the ileum. Symptomatic lesions that often present with abdominal pain, intestinal obstruction or bleeding are usually diagnosed and treated during infancy and childhood. However, many of these congenital conditions may remain clinically silent and detected incidentally in adults undergoing radiological evaluation for unrelated medical reasons. This article presents the spectrum of the congenital ileal anomalies and their distinct features on small bowel examination and CT of the abdomen.

Limy Bile Syndrome

Thu, 18 Jun 2026 00:00:00 +0000

Limy Bile Syndrome

Functional morphology of the lower esophageal sphincter and crural diaphragm determined by three-dimensional high-resolution esophago-gastric junction pressure profile and CT imaging

Thu, 18 Jun 2026 00:00:00 +0000

The smooth muscles of the lower esophageal sphincter (LES) and skeletal muscles of the crural diaphragm (CD) provide a closure/antireflux barrier mechanism at the esophago-gastric junction (EGJ). A number of questions in regard to the pressure profile of the LES and CD remain unclear, e.g., 1) Why is the LES pressure profile circumferentially asymmetric, 2) Is the crural diaphragm (CD) contraction also circumferentially asymmetric, and 3) Where is the LES and CD pressure profile located in the anatomy of the esophagus and stomach? The three-dimensional (3-D) high-resolution esophageal manometry (HRM) catheter can record a detailed profile of the EGJ pressure; however, it does not allow the determination of the circumferential orientation of individual pressure transducers in vivo. We used computed tomography (CT) scan imaging in combination with 3-D EGJ pressure recordings to determine the functional morphology of the LES and CD and its relationship to the...

CT and MR imaging of the properitoneal fat pad: a pictorial essay

Thu, 18 Jun 2026 00:00:00 +0000

The properitoneal fat pad is a distinctive anatomical structure located in the midline of anterior abdominal wall between the transversalis fascia and parietal peritoneum. It has variable size and configuration depending on the gender and nutritional status of individuals, but CT and MR images of the upper abdomen can readily depict its shape and adipose composition. The purpose of this essay is to illustrate the CT and MRI features of normal properitoneal fat pad, and the spectrum of pathological processes that affect it among patients. This information can be relevant to the practicing radiologists and clinicians for the correct diagnosis and management of such conditions because most lesions of this fat pad produce nonspecific symptoms.

Computed tomography of hyper-attenuated liver: Pictorial essay

Thu, 18 Jun 2026 00:00:00 +0000

Demonstration of a very dense or hyper-attenuated liver on the pre-contrast CT images of the abdomen can be an unexpected finding. It may present as a diagnostic challenge if the underlying cause of it is not apparent from the provided clinical history. There are about 12 different pathologic conditions that are associated with deposition of radiopaque elements within the hepatic parenchyma, resulting in diffuse or multi-lobar hyperdense appearance of the liver on abdominal radiographs and CT. Most of them are drug-induced or iatrogenic in nature, while others are the sequelae of genetic disorders like thalassemia, Wilson's disease, and primary hemochromatosis. This pictorial essay will present the CT appearance and etiology of hyper-attenuated liver in various clinical entities.

Imaging of eggshells and eggs in the gastrointestinal tract: pictorial essay

Thu, 18 Jun 2026 00:00:00 +0000

Ingestion of eggshell in its natural form or as ground and powdered product has become a popular means of dietary calcium supplementation in adults. These substances appear as conspicuous radiopaque material within the gastrointestinal tract on radiographs or computed tomography of the abdomen. The ingested eggshell fragments are usually visible as curvilinear structures on profile view, whereas the ground or powdered eggshells appear as granular densities. This article illustrates the spectrum of findings that are observed following eggshell ingestion by patients undergoing radiological evaluation for various unrelated medical conditions. Potential complications of eggshell consumption are discussed, and two cases of intra-rectal egg insertion for palliative relief of pelvic pain are presented.

Erdheim-Chester Disease

Thu, 18 Jun 2026 00:00:00 +0000

Erdheim-Chester Disease

Intraluminal Duodenal Diverticulum

Thu, 18 Jun 2026 00:00:00 +0000

Intraluminal Duodenal Diverticulum

Littre hernia in adults: imaging features and clinical implications

Thu, 18 Jun 2026 00:00:00 +0000

Littre hernia is an inguinal or abdominal wall herniation that contains a Meckel’s diverticulum alone or with other intestinal loops. The diagnosis is usually made at surgery, but its pre-operative radiological recognition has been a challenge due to inherent difficulties in detecting the Meckel’s diverticulum within hernial content. The aim of this article is to present 8 adults in whom a Meckel’s diverticulum protruding into their inguinal, umbilical or incisional hernia had been demonstrated by barium examination of the small bowel or colon, or on computed tomography and magnetic resonance imaging of the abdomen and pelvis. This series included 7 men and 1 woman, who ranged in age from 34 to 78 years (mean age:57 years). Seven patients had subsequent hernia repair, when the diverticulum was visualized and resected. This report highlights the imaging features of these 8 Littre hernias since only 5% of published cases had been diagnosed pre-operatively because the Meckel’s diverticulum...

CT and MR imaging of the greater omentum: Pictorial essay

Thu, 18 Jun 2026 00:00:00 +0000

The greater omentum is a unique anatomical structure that serves a critical function in the containment of inflammatory and infectious processes within the abdominal cavity. It is also a common site of involvement by metastases, as well as the primary location for various pathologic lesions of clinical significance. Its fibroadipose composition, large size, and position in the most anterior aspect of abdomen allow accurate visualization of the greater omentum on CT and MR images. Careful evaluation of the greater omentum can provide important clues to the diagnosis of the underlying abdominal disorder. The aim of this article is to present the normal appearance of the greater omentum, and the wide spectrum of its pathological features as demonstrated on CT and MRI of the abdomen.

Imaging Torus Lesions of Jaw Bones

Thu, 18 Jun 2026 00:00:00 +0000

Imaging Torus Lesions of Jaw Bones

Pulsion diverticula of the rectum: Radiological diagnosis and clinical implications

Thu, 18 Jun 2026 00:00:00 +0000

INTRODUCTION: The aim of this study was to investigate the appearance of acquired rectal diverticula on barium enema and computed tomography (CT) and to review the pertinent clinical data about this entity. METHODS: This series included 3 men and 6 women, who ranged in age from 47 to 82 years (average: 64 years). Air-contrast barium enema in 6 patients with history of anorectal disease or obstructed defecation demonstrated rectal diverticula. In these cases, multiple radiographs of the rectosigmoid region were obtained in upright position while the patient was relaxing or straining without any attempt to evacuate the barium. In 3 cases, the lateral rectal diverticula were incidental finding on CT studies that were performed for various unrelated abdominal complaints. RESULTS: Pulsion type of diverticulum presenting as a wide-neck outpouching was detected on the lateral rectal wall in 5 and on the posterior wall in 4 patients. They measured 2-3 cm in diameter when...

Intramural diverticulosis and diverticulitis of the colon: Pictorial essay

Thu, 18 Jun 2026 00:00:00 +0000

Diverticulosis of the colon is a gradually progressive disease that usually starts in early adulthood and increases with advancing age in its anatomical extent and the size of diverticula. It is important to recognize the initial stages of diverticular development in young patients in order to properly diagnose and manage the potential complications of this very common intestinal disorder. This article presents the pathological and radiological features of early diverticular formation, when the mucosal outpouchings are very small and contained within the colonic wall as distinct intramural lesions. The subsequent development of intramural diverticulitis and the spectrum of its manifestations on barium enema examination or Computed tomography (CT) are illustrated.

Allergy-induced urticaria of the colon

Thu, 18 Jun 2026 00:00:00 +0000

This article reports 2 adult patients who had developed an acute allergic reaction to food ingredients or medications, respectively. Both patients presented with concurrent urticaria of the skin and colon. The latter finding appeared as numerous raised plaques of the colonic mucosa on radiographic and computed tomography (CT) of the abdomen. The urticarial lesions affecting the skin and large bowel resembled each other and resolved after treatment with antihistamines. Pertinent clinical data and previously published cases of this unusual entity are briefly reviewed.

Krukenberg Tumors in Young Women: Computed Tomography and Magnetic Resonance Imaging Diagnosis

Thu, 18 Jun 2026 00:00:00 +0000

INTRODUCTION: The purpose of this report was to present the computed tomography (CT) and magnetic resonance imaging (MRI) features of Krukenberg tumors and to review the pertinent clinical data about the rising incidence of this malignancy among young women. MATERIAL AND METHODS: This series included 8 women who ranged in age from 24 to 44 years (mean, 36.3 years). They were diagnosed to have Krukenberg tumors during a 5-year period (2011-2016). All patients were evaluated by abdominal CT and pelvic or transvaginal sonography. Five of them also had MRI of the abdomen, and 3 had positron emission tomography scans. RESULTS: The primary cancer was located in the stomach of 7 patients and in the colon in 1. The initial presentation was due to large pelvic mass and abdominal distention by ascites in 3 patients, gastrointestinal symptoms in 4, and small bowel obstruction by carcinoma of the ascending colon in 1 woman. Ovarian metastases were demonstrated on the initial imaging examination...

Resurgence of intestinal ascariasis among adults: radiological diagnosis and clinical implications

Thu, 18 Jun 2026 00:00:00 +0000

To report the radiological features of intestinal ascariasis and to review the clinical implications of this re-emerging disease for adult population of the USA. This retrospective observational study involved 12 adult patients, whose radiological examinations disclosed unsuspected presence of ascaris in their intestinal tract. They were evaluated by computed tomography of the abdomen with oral contrast, small bowel series with barium, and magnetic resonance enterography. This series included 7 men and 5 women, who ranged in age from 19 to 72 years (mean age 48 years). The typical configuration of ascaris within the bowel loops was demonstrated on CT of the abdomen in 5 patients, small bowel examination with barium in 3, and by MR enterography in another 4 cases. Our study highlights the radiological appearances of intestinal ascariasis and the clinical implications of this resurging disease. The practicing radiologists should be aware of these findings, particularly...

Hepatic Peliosis

Thu, 18 Jun 2026 00:00:00 +0000

Hepatic Peliosis

Radiological features and clinical implications of persistent congenital mesocolon: Pictorial essay

Thu, 18 Jun 2026 00:00:00 +0000

In human foetus, the mesenteries that carry vascular and neural supply to the alimentary tube play an important role in its development and anatomical location within the abdominal cavity. The mesenteric attachments of the small bowel, transverse colon and sigmoid allow them to be intraperitoneally mobile structures. In contrast, the ascending and descending colon lose their mesenteries by fusion with the parietal peritoneum and become fixed in retroperitoneal position along the posterolateral walls of the abdomen. In about 2%-4% of individuals, this process is disrupted, causing a complete or partial retention of their congenital mesocolon. The ascending or descending colon will then remain intraperitoneally mobile, affecting the normal visceral anatomy and causing potential complications. This article reviews the spectrum of radiological manifestations and clinical consequences of these anomalies.

Accidental or intentional ingestion of toothbrushes: experience with 8 adult patients

Thu, 18 Jun 2026 00:00:00 +0000

PurposeIngestion of a toothbrush is an unusual event but may occur either accident or by intent. Radiological examinations play a crucial role in determining the exact location of the object within the gastrointestinal tract and in planning for its removal by endoscopic or surgical intervention.MethodsMedical and radiological records of 8 patients who had swallowed the broken heads or entire toothbrush were retrospectively reviewed. This series included 4 men and 4 women, ranging in age from 21 to 57 years (mean: 34 years).ResultsRadiographs and computed tomography of the abdomen demonstrated the ingested toothbrushes within the stomach in 3, lodged in the duodenum in 1, and entrapped in various parts of the colon in 4 patients. They were removed by laparotomy in 3, laparoscopy in 2, colonoscopy in 2, and upper gastrointestinal endoscopy in 1 patient. There were no perforations or associated complications, and all patients had uneventful recoveries.ConclusionsIngested toothbrushes...

Giant Sigmoid Diverticulum: Imaging Features and Management

Thu, 18 Jun 2026 00:00:00 +0000

Giant Sigmoid Diverticulum: Imaging Features and Management

Hepatic Peliosis

Thu, 18 Jun 2026 00:00:00 +0000

Hepatic Peliosis

Withdrawal: “Torus lesions of the jaw: Diagnosis and clinical implications” Gary G. Ghahremani, David R. Naimi, Zohreh K. Ghahremani

Thu, 4 Jun 2026 00:00:00 +0000

Withdrawal: “Torus lesions of the jaw: Diagnosis and clinical implications” Gary G. Ghahremani, David R. Naimi, Zohreh K. Ghahremani

Optimizing Screening of Hepatocellular Carcinoma with Computed Tomography and MR Imaging Emerging Research, Updated Guidelines, and New Technologies

Thu, 4 Jun 2026 00:00:00 +0000

Ultrasound is the standard first-line imaging modality for hepatocellular carcinoma (HCC) screening; however, in certain patient populations, sensitivity is limited, and thus alternative strategies are needed in these patients. This article will provide an overview of MR imaging and computed tomography (CT) for the screening of HCC, with an emphasis on abbreviated MR imaging protocols and recent advancements in CT technology (dual energy and photon-counting CT).

Intraperitoneal Barium From Gastrointestinal Perforations: Reassessment of the Prognosis and Long-Term Effects.

Thu, 4 Jun 2026 00:00:00 +0000

OBJECTIVE. The purpose of this study was to reassess the outcome and potential consequences of intraperitoneal barium leakage during radiologic evaluation of the gastrointestinal tract. MATERIALS AND METHODS. This retrospective study included 18 patients who had significant intraperitoneal leakage of barium from gastrointestinal perforations that were not suspected or diagnosed before the radiologic procedures. This complication occurred during a barium enema examination in nine patients, an upper gastrointestinal study in seven, and a small bowel series in two patients. All patients underwent urgent laparotomy for repair of perforation, with vigorous peritoneal lavage and antibiotic therapy. RESULTS. All patients had an uneventful recovery and were followed for 4-17 years (mean, 8.5 years). Radiographs obtained during this interval showed that a significant amount of residual barium was retained in the abdominal cavity. Six patients had a total of 10 subsequent...

Retrograde Jejunogastric Intussusception and Novel Reduction

Thu, 4 Jun 2026 00:00:00 +0000

Retrograde Jejunogastric Intussusception and Novel Reduction

The 2024 Brain Tumor Segmentation (BraTS) Challenge: Glioma Segmentation on Post-treatment MRI

Thu, 23 Apr 2026 00:00:00 +0000

Gliomas are the most common malignant primary brain tumors in adults and one of the deadliest types of cancer. There are many challenges in treatment and monitoring due to the genetic diversity and high intrinsic heterogeneity in appearance, shape, histology, and treatment response. Treatments include surgery, radiation, and systemic therapies, with magnetic resonance imaging (MRI) playing a key role in treatment planning and post-treatment longitudinal assessment. The 2024 Brain Tumor Segmentation (BraTS) challenge on post-treatment glioma MRI will provide a community standard and benchmark for state-of-the-art automated segmentation models based on the largest expert-annotated post-treatment glioma MRI dataset. Challenge competitors will develop automated segmentation models to predict four distinct tumor sub-regions consisting of enhancing tissue (ET), surrounding non-enhancing T2/fluid-attenuated inversion recovery (FLAIR) hyperintensity (SNFH), non-enhancing tumor core (NETC),...

Radiomics-based Machine Learning Prediction of Neoadjuvant Chemotherapy Response in Breast Cancer Using Physiologically Decomposed Diffusion-weighted MRI.

Thu, 12 Mar 2026 00:00:00 +0000

Purpose To evaluate the performance of a machine learning model developed using radiomics data derived from physiologically decomposed diffusion-weighted MRI data for predicting pathologic complete response (pCR) following neoadjuvant chemotherapy for breast cancer compared with baseline and benchmark models. Materials and Methods This retrospective study included data from the Breast Multiparametric MRI for prediction of neoadjuvant chemotherapy Response (BMMR2) challenge dataset, comprising longitudinal multiparametric breast MRI studies (diffusion-weighted imaging [DWI] and dynamic contrast-enhanced MRI) from participants enrolled in the I-SPY 2/ACRIN 6698 trial (ClinicalTrials.gov: NCT01042379). Piecewise linear physiologic decomposition was applied to DWI data (PD DWI) to isolate pseudo-diffusion, pure-diffusion, and pseudo-diffusion fraction components for radiomics feature extraction. These features were used to develop a boosted decision tree model to predict pCR following...

Bicomponent Mapping of Cortical Bone Using a New Interleaved UTE Imaging Sequence

Thu, 15 Jan 2026 00:00:00 +0000

PURPOSE: Ultrashort echo time (UTE) MRI enables direct imaging of cortical bone and quantification of its water compartments via bicomponent T₂* modeling. However, conventional approaches require multiple separate dual-echo scans due to limitations in gradient power. This approach is prone to inter-scan inconsistencies such as motion and signal drift, which degrade fitting accuracy. This study proposes an interleaved dual-echo acquisition sequence that acquires multiple echo time (TE) images in a single scan to improve bicomponent T₂* quantification in cortical bone. METHODS: The proposed UTE sequence utilizes interleaved dual-echo acquisitions with flexible TE spacings. This sequence was tested on five healthy subjects' tibial midshafts and compared to conventional separate dual-echo scans with and without image registration. Bicomponent T₂* modeling was performed, and fitting accuracy was evaluated using normalized-root-mean-squared error (NRMSE)....

Chapter 7 Nano-immunoimaging

Thu, 15 Jan 2026 00:00:00 +0000

In the vast landscape of biomedical research, the development and subsequent convergence of nanotechnology and in vivo imaging modalities have given rise to a powerful field known as nano-immunoimaging. Nano-immunoimaging can be succinctly defined as the amalgamation of nanotechnology and immunological principles to visualize, monitor and manipulate immune responses at the molecular, cellular, and systemic levels. The purpose of the nano-immunoimaging field has been to relentlessly push resolution boundaries to make individual cells and molecules visible. This chapter will begin with a primer on different imaging modalities available in preclinical research and the clinic and their associated contrast agents. Recent applications using the ever-expanding immunoimaging toolbox as well as clinical platforms will be presented in this chapter.

CRISPR-based Triple-Modality Imaging Ushers a New Era for Stem Cell Tracking in Stroke.

Thu, 15 Jan 2026 00:00:00 +0000

“Just Accepted” papers have undergone full peer review and have been accepted for publication in Radiology. This article will undergo copyediting, layout, and proof review before it is published in its final version. Please note that during production of the final copyedited article, errors may be discovered which could affect the content.

Multimodal tilmanocept for preoperative imaging and fluorescence-guided surgery of porcine lateral pelvic sentinel lymph nodes

Fri, 5 Dec 2025 00:00:00 +0000

The management of lateral pelvic lymph nodes in locally advanced lower rectal cancer remains controversial. The sentinel lymph node (SLN) mapping can potentially enhance patient selection for lateral pelvic lymph node dissection. The current mapping agent, indocyanine green dye cannot be externally imaged prior to surgery and is not retained after entering the SLN. This study evaluated the ability of tilmanocept, a receptor-specific SLN mapping agent, to provide preoperative PET cross-sectional imaging and sustained intraoperative fluorescence images during rectal cancer surgery. Tilmanocept was labeled with gallium-68, technetium-99m, and a near-infrared fluorophore. Four pigs were studied. Tilmanocept was injected into the submucosal layer of the rectal wall followed 1 h later by PET/CT images of the pelvis, which identified ten SLNs, one of which was a pudendal artery regional SLN. Approximately 45 h after administration, SLN dissection was guided by fluorescence...

Standardized reporting of extrahepatic cholangiocarcinoma

Thu, 9 Oct 2025 00:00:00 +0000

Cholangiocarcinoma, a primary epithelial malignancy originating in the biliary tree, can be classified based on anatomical location into intrahepatic and extrahepatic cholangiocarcinoma. Extrahepatic cholangiocarcinoma (eCCA) is the more common of the two. CT and MRI play a central role in the diagnosis, staging, and management of eCCA, yet radiological reporting of eCCA often lacks uniformity and completeness which can hamper optimal treatment decision-making. Standardized reporting including standardized terminology and structured reports can address these shortcomings. Standardization produces clear, concise, and accurate terminology to facilitate communication between radiologists, surgeons, oncologists, pathologists, and interventionalists, which can be particularly important in complex cases where treatment hinges on discerning fine anatomical details. Structured report templates organize reporting elements in ordered sections to ensure consistency and completeness when...

Surveillance donor-specific antibody and pathologic antibody-mediated rejection testing in heart transplant patients in the contemporary era

Thu, 14 Aug 2025 00:00:00 +0000

BACKGROUND: Surveillance donor-specific antibody (DSA) and pathologic antibody-mediated rejection (pAMR) testing is recommended in the first year after heart transplantation (HTx) in adult patients. Whether pAMR testing adds prognostic information to contemporary DSA testing has not been fully studied. METHODS: This was a single-center study of consecutive endomyocardial biopsies (EMB) performed between November 2010 and February 2023 in adult HTx patients. The primary objective was to evaluate whether pAMR testing contributes additional information to DSA testing to better predict overall survival. Secondary end-points included cardiac survival and allograft dysfunction. RESULTS: A total of 6,033 EMBs from 544 HTx patients were reviewed for the study. The pAMR+/DSA+ patients had significantly lower overall (p_c = 0.013) and cardiac survival (p_c = 0.002), while the pAMR+/DSA- and pAMR-/DSA+ patients showed no difference in either outcome compared...

A Pediatric Cardiac Shape Atlas: Insights into the Structure of Young Healthy Hearts

Thu, 17 Jul 2025 00:00:00 +0000

A Pediatric Cardiac Shape Atlas: Insights into the Structure of Young Healthy Hearts

TRACT-BASED SPATIAL STATISTICS FROM DIFFUSION-WEIGHTED MRI REVEAL SPECIFIC WHITE MATTER CORRELATES OF GLOBAL MOTION SENSITIVITY IN TYPICALLY DEVELOPING CHILDREN

Thu, 22 May 2025 00:00:00 +0000

TRACT-BASED SPATIAL STATISTICS FROM DIFFUSION-WEIGHTED MRI REVEAL SPECIFIC WHITE MATTER CORRELATES OF GLOBAL MOTION SENSITIVITY IN TYPICALLY DEVELOPING CHILDREN

In vivo periodontal ultrasound imaging via a hockey-stick transducer and comparison to periodontal probing: a proof-of-concept study

Thu, 8 May 2025 00:00:00 +0000

ObjectiveThe objective of this study is to evaluate a compact ultrasound transducer to image anatomical biomarkers for periodontal diagnosis of teeth, including difficult-to-reach posterior teeth.Materials and methodsA 9-MHz hockey-stick transducer was used to image 53 premolars, 30 molars, and 79 incisors and canines from 13 subjects. The alveolar bone crest (ABC), cementoenamel junction (CEJ), and gingival margin (GM) were identified by ultrasound imaging. The image-based distances between these anatomic landmarks were measured for iABC (ABC to CEJ), iGR (GM to CEJ) and iGH (ABC to GM). The measurements were compared to corresponding parameters obtained from clinical examination. The measurements were also used to assess periodontal health and were compared with clinical diagnosis.ResultsThe average iGR measurements were − 1.12 mm (i.e., 1.12 mm above the CEJ) for gingivitis and Stage I periodontitis, and − 0.56 mm for Stage III periodontitis, demonstrating a...

Responsible use of population neuroscience data: Towards standards of accountability and integrity

Mon, 14 Apr 2025 00:00:00 +0000

This editorial focuses on the issue of data misuse which is increasingly evidenced in social media as well as some premiere scientific journals. This issue is of critical importance to open science projects in general, and ABCD in particular, given the broad array of biological, behavioral and environmental information collected on this American sample of 12.000 youth and parents. ABCD data are already widely used with over 1000 publications and twice as many citations per year as expected (relative citation index based on year, field and journal). However, the adverse consequences of misuse of data, and inaccurate interpretation of emergent findings from this precedent setting study may have profound impact on disadvantaged populations and perpetuate biases and societal injustices.

Coronary Artery Calcium Detection with Dual-Energy Posteroanterior and Lateral Chest Radiography: Imaging Clues and Added Value of the Lateral View.

Sun, 13 Apr 2025 00:00:00 +0000

Purpose To evaluate the accuracy of detection based on level of interpreter experience when reporting coronary artery calcium (CAC) on dual-energy (DE) posteroanterior (PA) and lateral chest radiographs and demonstrate the accuracy of specific imaging clues. Materials and Methods Retrospective review of 45-70-year-old patients who underwent DE PA and lateral chest radiography between March 1, 2021, and June 30, 2021, and also underwent noncontrast chest CT scan within 3 years. Following instruction of DE principles and the appearance of CAC, seven readers interpreted the DE chest radiographs to state if CAC was possibly present, definitely present, or not present; estimate ordinal CAC score; and report imaging clues present. Results Ninety-nine patients were selected (mean age, 58.6 years; 53 male and 46 female patients). Among the 62 patients with CAC, the median score was 92. The median CAC score among seven readers when detected ranged from 120 to 203 and when not detected...

Genome‐wide analyses reveal novel opioid use disorder loci and genetic overlap with schizophrenia, bipolar disorder, and major depression

Wed, 2 Apr 2025 00:00:00 +0000

Opioid use disorder (OUD) and mental disorders are often comorbid, with increased morbidity and mortality. The causes underlying this relationship are poorly understood. Although these conditions are highly heritable, their shared genetic vulnerabilities remain unaccounted for. We applied the conditional/conjunctional false discovery rate (cond/conjFDR) approach to analyse summary statistics from independent genome wide association studies of OUD, schizophrenia (SCZ), bipolar disorder (BD) and major depression (MD) of European ancestry. Next, we characterized the identified shared loci using biological annotation resources. OUD data were obtained from the Million Veteran Program, Yale-Penn and Study of Addiction: Genetics and Environment (SAGE) (15 756 cases, 99 039 controls). SCZ (53 386 cases, 77 258 controls), BD (41 917 cases, 371 549 controls) and MD (170 756 cases, 329 443 controls) data were provided by the Psychiatric Genomics Consortium. We discovered genetic enrichment...

Social Determinants of Health in Imaging-based Cancer Screening: A Case-based Primer with Strategies for Care Improvement.

Wed, 2 Apr 2025 00:00:00 +0000

Health disparities, preventable differences in the burden of disease and disease outcomes often experienced by socially disadvantaged populations, can be found in nearly all areas of radiology, including emergency radiology, neuroradiology, nuclear medicine, image-guided interventions, and imaging-based cancer screening. Disparities in imaging-based cancer screening are especially noteworthy given the far-reaching population health impact. The social determinants of health (SDoH) play an important role in disparities in cancer screening and outcomes. Through improved understanding of how SDoH can drive differences in health outcomes in radiology, radiologists can effectively provide patient-centered, high-quality, and equitable care. Radiologists and radiology practices can become active partners in efforts to assist patients along their imaging journey and overcome existing barriers to equitable cancer screening care for traditionally marginalized populations. As radiology exists...

Estimation of Trabecular Bone Volume with Dual-Echo Ultrashort Echo Time (UTE) Magnetic Resonance Imaging (MRI) Significantly Correlates with High-Resolution Computed Tomography (CT)

Wed, 2 Apr 2025 00:00:00 +0000

Trabecular bone architecture has important implications for the mechanical strength of bone. Trabecular elements appear as signal void when imaged utilizing conventional magnetic resonance imaging (MRI) sequences. Ultrashort echo time (UTE) MRI can acquire high signal from trabecular bone, allowing for quantitative evaluation. However, the trabecular morphology is often disturbed in UTE-MRI due to chemical shift artifacts caused by the presence of fat in marrow. This study aimed to evaluate a UTE-MRI technique to estimate the trabecular bone volume fraction (BVTV) without requiring trabecular-level morphological assessment. A total of six cadaveric distal tibial diaphyseal trabecular bone cubes were scanned using a dual-echo UTE Cones sequence (TE = 0.03 and 2.2 ms) on a clinical 3T MRI scanner and on a micro-computed tomography (μCT) scanner. The BVTV was calculated from 10 consecutive slices on both the MR and μCT images. BVTV calculated from the MR images showed strongly significant...

Ultrashort Echo Time Magnetic Resonance Morphology of Discovertebral Junction in Chronic Low Back Pain Subjects

Wed, 2 Apr 2025 00:00:00 +0000

Background: Chronic low back pain (LBP) has been associated with intervertebral disc (IVD) degeneration, but its association with abnormal morphology at the discovertebral junction (DVJ) is unclear. The goal of this study was to evaluate the DVJ morphology in asymptomatic (Asx) and symptomatic (Sx) subjects for LBP using ultrashort echo time (UTE) MRI. Methods: We recruited 42 subjects (12 Asx and 32 Sx). Lumbar IVD degeneration was assessed using Pfirrmann grading (1 to 5), while the abnormality of DVJ (0 = normal; 1 = focal; 2 = broad abnormality) was assessed using UTE MRI. The effects of LBP and level on the mean IVD and DVJ grades, the correlation between IVD and DVJ grade, and the effect of LBP and age on the number of abnormal DVJs within a subject were determined. Results: IVD grade was higher in Sx subjects (p = 0.013), varying with disc level (p = 0.033), adjusted for age (p < 0.01). Similarly, DVJ grade was also significantly...

Neurovascular crossing patterns between leash of Henry and deep branch of radial nerve: implications for neurointervention and diagnostic imaging

Mon, 24 Mar 2025 00:00:00 +0000

ObjectiveTo detail the neurovascular crossing patterns between the leash of Henry (LoH) and the deep branch of the radial nerve (DBRN) in supination and pronation of the forearm, using imaging methods with anatomic correlation.Materials and methodsThis cross-sectional study was performed ex vivo with HRUS and MRI with anatomic correlation on 6 samples and in vivo with HRUS with Doppler on 55 participants scanned bilaterally. The in vivo participants were enrolled over a 6-month period. The crossing patterns between the LoH and DBRN were assessed ex vivo and in vivo. Additional morphological features of the DBRN, LoH, and fat plane were assessed in vivo only. Biometric features of the participants were recorded. Statistical analyses were performed using Shapiro–Wilk, parametric and non-parametric tests.ResultsThe most common neurovascular crossing pattern was the ascending branch of the radial recurrent artery (RRAab) crossing below (ex vivo: 83.3%, in vivo: 85.3%) and the muscular...

Transcranial volumetric imaging using a conformal ultrasound patch

Fri, 21 Mar 2025 00:00:00 +0000

Accurate and continuous monitoring of cerebral blood flow is valuable for clinical neurocritical care and fundamental neurovascular research. Transcranial Doppler (TCD) ultrasonography is a widely used non-invasive method for evaluating cerebral blood flow1, but the conventional rigid design severely limits the measurement accuracy of the complex three-dimensional (3D) vascular networks and the practicality for prolonged recording2. Here we report a conformal ultrasound patch for hands-free volumetric imaging and continuous monitoring of cerebral blood flow. The 2 MHz ultrasound waves reduce the attenuation and phase aberration caused by the skull, and the copper mesh shielding layer provides conformal contact to the skin while improving the signal-to-noise ratio by 5 dB. Ultrafast ultrasound imaging based on diverging waves can accurately render the circle of Willis in 3D and minimize human errors during examinations. Focused ultrasound waves allow the recording of blood flow...

Contrast-enhanced ultrasound of renal masses in the pre-transplant setting: literature review with case highlights

Fri, 21 Mar 2025 00:00:00 +0000

With the rising incidence of chronic kidney disease worldwide, an increasing number of patients are expected to require renal transplantation, which remains the definitive treatment of end stage renal disease. Medical imaging, primarily ultrasonography and contrast-enhanced CT and/or MRI, plays a large role in pre-transplantation assessment, especially in the characterization of lesions within the native kidneys. However, patients with CKD/ESRD often have relative contraindications to CT- and MR-contrast agents, limiting their utilization within this patient population. Contrast-enhanced ultrasound (CEUS), which combines the high temporal and spatial resolution of ultrasonography with intravascular microbubble contrast agents, provides a promising alternative. This review aims to familiarize the reader with the literature regarding the use of CEUS in the evaluation of cystic and solid renal lesions and provide case examples of its use at our institution in the pre-transplant setting.Graphical...

Quantitative myelin water imaging using short TR adiabatic inversion recovery prepared echo-planar imaging (STAIR-EPI) sequence

Tue, 18 Mar 2025 00:00:00 +0000

Introduction: Numerous techniques for myelin water imaging (MWI) have been devised to specifically assess alterations in myelin. The biomarker employed to measure changes in myelin content is known as the myelin water fraction (MWF). The short TR adiabatic inversion recovery (STAIR) sequence has recently been identified as a highly effective method for calculating MWF. The purpose of this study is to develop a new clinical transitional myelin water imaging (MWI) technique that combines STAIR preparation and echo-planar imaging (EPI) (STAIR-EPI) sequence for data acquisition. Methods: Myelin water (MW) in the brain has shorter T₁ and T₂ relaxation times than intracellular and extracellular water. In the proposed STAIR-EPI sequence, a short TR (e.g., ≤300 ms) together with an optimized inversion time enable robust long T₁ water suppression with a wide range of T₁ values [i.e., (600, 2,000) ms]. The EPI allows...

Interpretation, Reporting, and Clinical Applications of Liver MR Elastography.

Tue, 18 Mar 2025 00:00:00 +0000

Chronic liver disease is highly prevalent and often leads to fibrosis or cirrhosis and complications such as liver failure and hepatocellular carcinoma. The diagnosis and staging of liver fibrosis is crucial to determine management and mitigate complications. Liver biopsy for histologic assessment has limitations such as sampling bias and high interreader variability that reduce precision, which is particularly challenging in longitudinal monitoring. MR elastography (MRE) is considered the most accurate noninvasive technique for diagnosing and staging liver fibrosis. In MRE, low-frequency vibrations are applied to the abdomen, and the propagation of shear waves through the liver is analyzed to measure liver stiffness, a biomarker for the detection and staging of liver fibrosis. As MRE has become more widely used in clinical care and research, different contexts of use have emerged. This review focuses on the latest developments in the use of MRE for the assessment of liver fibrosis;...

Association of LR treatment response category with outcome of patients with hepatocellular carcinoma on explant pathology

Thu, 13 Mar 2025 00:00:00 +0000

ObjectivesLiver transplant (LT) is an effective treatment for hepatocellular carcinoma (HCC) in appropriately selected patients. Locoregional therapy (LRT) is often performed to extend a patient’s eligibility for LT. Imaging has a modest sensitivity of approximately 40–77% for detecting pathologically viable HCC in post-LRT patients. The impact on overall survival (OS) and disease-free survival (DFS) is unclear. We hypothesize that Liver Imaging Reporting & Data Systems Treatment Response (LI-RADS TR) category is equivalently correlated with long-term survival and overall disease-free progression when compared to explant pathology findings. We additionally hypothesize that neoadjuvant LRT can improve OS and DFS in LT patients initially within MC.MethodsPatients found to have HCC on explant between January 2005 and December 2021 were included. A total of 167 patients were divided into treatment (any pre-LT LRT except for Y-90 therapy) and control (no pre-LT LRT) groups. Of...

Shared genetic loci between Alzheimer's disease and multiple sclerosis: Crossroads between neurodegeneration and immune system

Tue, 11 Mar 2025 00:00:00 +0000

BACKGROUND: Neuroinflammation is involved in the pathophysiology of Alzheimer's disease (AD), including immune-linked genetic variants and molecular pathways, microglia and astrocytes. Multiple Sclerosis (MS) is a chronic, immune-mediated disease with genetic and environmental risk factors and neuropathological features. There are clinical and pathobiological similarities between AD and MS. Here, we investigated shared genetic susceptibility between AD and MS to identify putative pathological mechanisms shared between neurodegeneration and the immune system. METHODS: We analysed GWAS data for late-onset AD (N cases = 64,549, N controls = 634,442) and MS (N cases = 14,802, N controls = 26,703). Gaussian causal mixture modelling (MiXeR) was applied to characterise the genetic architecture and overlap between AD and MS. Local genetic correlation was investigated with Local Analysis of [co]Variant Association (LAVA). The conjunctional false...

Motion correction of wide-detector 4DCT images for cardiac resynchronization therapy planning

Mon, 10 Mar 2025 00:00:00 +0000

BACKGROUND: Lead placement at the latest mechanically activated left ventricle (LV) segments is strongly correlated with response to cardiac resynchronization therapy (CRT). We demonstrate the feasibility of a cardiac 4DCT motion correction algorithm (ResyncCT) in estimating LV mechanical activation for guiding lead placement in CRT. METHODS: Subjects with full cardiac cycle 4DCT images acquired using a wide-detector CT scanner for CRT planning/upgrade were included. 4DCT images exhibited motion artifact-induced false-dyssynchrony, hindering LV mechanical activation time estimation. Motion-corrupted images were processed with ResyncCT to yield motion-corrected images. Time to onset of shortening (TOS) was estimated in each of 72 endocardial segments. A false-dyssynchrony index (FDI) was used to quantify the extent of motion artifacts in the uncorrected and the ResyncCT images. After motion correction, the change in classification of LV free-wall segments as optimal target sites...

Genome-wide analyses reveal shared genetic architecture and novel risk loci between opioid use disorder and general cognitive ability

Mon, 3 Mar 2025 00:00:00 +0000

BACKGROUND: Opioid use disorder (OUD), a serious health burden worldwide, is associated with lower cognitive function. Recent studies have demonstrated a negative genetic correlation between OUD and general cognitive ability (COG), indicating a shared genetic basis. However, the specific genetic variants involved, and the underlying molecular mechanisms remain poorly understood. Here, we aimed to quantify and identify the genetic basis underlying OUD and COG. METHODS: We quantified the extent of genetic overlap between OUD and COG using a bivariate causal mixture model (MiXeR) and identified specific genetic loci applying conditional/conjunctional FDR. Finally, we investigated biological function and expression of implicated genes using available resources. RESULTS: We estimated that ~94% of OUD variants (4.8k out of 5.1k variants) also influence COG. We identified three novel OUD risk loci and one locus shared between OUD and COG. Loci identified implicated biological substrates...

Pulmonary regional blood flow: validation of low-dose two-volume dynamic CT perfusion imaging in a swine model

Sat, 1 Mar 2025 00:00:00 +0000

BackgroundWe aimed to validate a low-dose two-volume pulmonary computed tomography (CT) perfusion technique.MethodsFive Yorkshire swine (weight 53.6 ± 2.6 kg) underwent 21 independent CT perfusion acquisitions. Intravenous contrast material (370 mg/mL iodine, 0.5 mL/kg) and saline chaser (0.5 mL/kg) were injected at 5 mL/s for each acquisition. Two-volume and multivolume dynamic CT perfusion data were acquired using a 320-slice CT, with multivolume measurements serving as the reference standard. The two-volume CT perfusion involved a low-dose (50 mA) volume scan before contrast injection and a diagnostic (300 mA) volume scan after bolus-tracking in the main pulmonary artery at the peak contrast enhancement. Multivolume CT perfusion included 15–20 volume scans for blood flow measurement. Paired sample t-test, linear regression, and Bland–Altman analysis compared both global and regional two-volume perfusion measurements to the reference standard. The reproducibility of the two-volume...

Neurocognitive and brain structure correlates of reading and television habits in early adolescence

Fri, 28 Feb 2025 00:00:00 +0000

Results of the impact of reading books and viewing television on neurodevelopment have been mixed, without definitive evaluation to date. Using data from 11,875 US adolescents in the Adolescent Brain and Cognitive Development (ABCD) study, we investigated the associations between reading and television viewing on brain morphology and neurocognitive performance. After quality control, 8,125 participants’ MRI scans and cognitive tests were analyzed in relation to their reading and TV habits. Greater reading time was associated with higher cognitive performance and regionally-selective increases in cortical area, while greater TV viewing had a much smaller association with lower cognitive performance and decreased cortical area. Regionally, areas of spatial overlap in associations included the lateral temporal, inferior parietal, and inferior frontal lobes, while significant associations in the ventral and inferior temporal cortex and cingulate cortex were unique to reading habits....

The Adolescent Brain Cognitive Development Study

Fri, 28 Feb 2025 00:00:00 +0000

The Adolescent Brain Cognitive Development (ABCD) Study was launched by the Collaborative Research on Addiction at NIH (CRAN) in 2016 and is now supported by 11 other federal agencies and centers. The six primary aims of ABCD were to: Develop national standards for normal brain development for youth ages 9-19 years; Determine individual developmental trajectories (e.g., brain, cognitive, and emotional development, academic progress), and identify factors that can influence (protectively or adversely) these developmental patterns; Examine the roles of genetic, cultural, and environmental factors in youth development, as well as their interactions; Evaluate the effects of health, physical activity, sleep, social activities, sports injuries, and other experiences on brain and developmental outcomes; Assess the onset and progression of mental health (MH) disorders and factors that influence their course and severity as well as the relations between MH and substance use (SU); Determine...

Multivariate genome-wide association study identifies 780 unique genetic loci associated with cortical morphology

Fri, 28 Feb 2025 00:00:00 +0000

Abstract Brain morphology has been shown to be highly heritable, yet only a small portion of the heritability is explained by the genetic variants discovered so far. Here we exploit the distributed nature of genetic effects across the brain and apply the Multivariate Omnibus Statistical Test (MOSTest) to genome-wide association studies (GWAS) of vertex-wise structural magnetic resonance imaging (MRI) cortical measures from N=35,657 participants in the UK Biobank. We identified 695 loci for cortical surface area and 539 for cortical thickness, in total 780 unique genetic loci associated with cortical morphology. This reflects an approximate 10-fold increase compared to the commonly applied univariate GWAS methods. Power analysis indicates that applying MOSTest to vertex-wise structural MRI data triples the effective sample size compared to conventional univariate GWAS approaches. Functional follow up including gene-based analyses implicate 10% of all protein-coding genes and point...

Precision medicine and global mental health

Fri, 28 Feb 2025 00:00:00 +0000

Precision medicine and global mental health

Brain and Cognitive Development

Fri, 28 Feb 2025 00:00:00 +0000

Abstract: This chapter presents a unified model of neurocognitive development beginning with the differentiation of the first neural cells and extending through the emergence of complex thought and behavior. It draws on the latest data from neurobiology, multimodal brain imaging, and cognitive neuroscience to construct a developmental model of the emergence of the human neurocognitive system from the dynamic interaction of diverse biological and experiential factors. The chapter begins with brief descriptions of the major methods for interrogating questions about brain‐behavior relations focusing primarily on neuroimaging technologies. The next section provides an overview of anatomical brain development beginning in the prenatal period and extending through adolescence. The third section represents the heart of this chapter using data from three major cognitive domains to explore principles that underlie the development of brain‐behavior relationships. The targeted domains are...

Neuroticism is linked to microstructural left-right asymmetry of fronto-limbic fibre tracts in adolescents with opposite effects in boys and girls

Fri, 28 Feb 2025 00:00:00 +0000

Neuroticism is a fundamental personality trait that reflects a tendency to experience heightened negative affect and susceptibility to stress. Negative emotionality has been associated with fronto-limbic brain structures and connecting fibre tracts. The major fibre tracts connecting the frontal and limbic brain regions are the cingulum bundle and uncinate fasciculus. We previously found that healthy adults with higher neuroticism scores had decreased left relative to right fractional anisotropy (FA) of the cingulum. Both cingulum and uncinate fasciculus FA increases throughout childhood and into early adulthood. Since adolescence is associated with an increased incidence of anxiety and mood disorders, for which neuroticism is a known risk factor, the question arises whether the association between neuroticism and fronto-limbic white matter microstructure asymmetry is already present in children and adolescents or whether such relationship emerges during this age period. To address...

Evaluation of the Femoral Condyle Radius of Curvature at the Chondral Surface Shows Significant Correlation With the Anterior-Posterior Length.

Mon, 17 Feb 2025 00:00:00 +0000

BACKGROUND: Accurate donor-recipient matching of the femoral condyle radius of curvature (ROC) in osteochondral allograft (OCA) transplantation may aid in minimizing articular surface incongruities. Matching linear femorotibial dimensions, such as the femoral condyle anterior-posterior length (APL), femoral condyle width (lateral-medial length, LML), femoral hemicondyle width (HCW), and tibial plateau width (TPW), can provide similar results if they correlate well with ROC. This study investigates the relationship between femorotibial dimensions and ROC at the cartilage surface using magnetic resonance imaging (MRI). METHODS: Deidentified MRI images of 63 patients (35 men, 33 ± 10 years old, and 28 women, 27 ± 8 years old) were analyzed. Axial images were used for APL, LML, and TPW (TPW-Ax) measurements, while coronal images were used for HCW and TPW (TPW-Cor) measurements. Cartilage was segmented in true sagittal images at the medial femoral condyle (MFC) and lateral femoral...

Polygenic overlap with granulocyte counts identifies novel loci for clozapine metabolism and clozapine-induced agranulocytosis

Fri, 14 Feb 2025 00:00:00 +0000

While clozapine is the most effective antipsychotic drug, its use is limited due to hematological adverse effects involving the reduction of granulocyte counts with potential life-threatening agranulocytosis. It is not yet possible to predict or prevent the risk of agranulocytosis, and the mechanisms are unknown but likely related to clozapine metabolism. Genome-wide association studies (GWASs) of clozapine metabolism and clozapine-induced agranulocytosis have identified few genetic loci. We used the largest available GWAS summary statistics of clozapine metabolism (clozapine-to-norclozapine ratio) and clozapine-induced agranulocytosis, applying the conditional false discovery rate (condFDR) method to increase power for genetic discovery by conditioning on granulocyte counts variants. To investigate potential causal effects of shared loci, we performed Mendelian Randomization analyses. After conditioning on granulocyte counts, we identified two novel loci associated with clozapine-to-norclozapine...

Genomic analysis of intracranial and subcortical brain volumes yields polygenic scores accounting for variation across ancestries

Fri, 14 Feb 2025 00:00:00 +0000

Subcortical brain structures are involved in developmental, psychiatric and neurological disorders. We performed GWAS meta-analyses of intracranial and nine subcortical brain volumes (brainstem, caudate nucleus, putamen, hippocampus, globus pallidus, thalamus, nucleus accumbens, amygdala and, for the first time, the ventral diencephalon) in 74,898 participants of European ancestry. We identified 254 independent loci associated with these brain volumes, explaining up to 35% of phenotypic variance. We observed gene expression in specific neural cell types across differentiation time points, including genes involved in intracellular signalling and brain ageing-related processes. Polygenic scores for brain volumes showed predictive ability when applied to individuals of diverse ancestries. We observed causal genetic effects of brain volumes with Parkinson's disease and ADHD. Findings implicate specific gene expression patterns in brain development and genetic variants in comorbid...

Advanced Restriction imaging and reconstruction Technology for Prostate MRI (ART-Pro): Study protocol for a multicenter, multinational trial evaluating biparametric MRI and advanced, quantitative diffusion MRI for detection of prostate cancer

Fri, 14 Feb 2025 00:00:00 +0000

Abstract: Background: Multiparametric MRI (mpMRI) is strongly recommended by current clinical guidelines for improved detection of clinically significant prostate cancer (csPCa). However, major limitations of mpMRI are the need for intravenous (IV) contrast and dependence on reader expertise. Efforts to address these issues include use of biparametric MRI (bpMRI) and advanced, quantitative MRI techniques. One such advanced technique is the Restriction Spectrum Imaging restriction score (RSIrs), an imaging biomarker that has been shown to improve quantitative accuracy of patient-level csPCa detection. Purpose: To evaluate whether IV contrast can be avoided in the setting of standardized, state-of-the-art image acquisition, with or without addition of RSIrs, and to evaluate characteristics of RSIrs as a stand-alone, quantitative biomarker. Design, setting, and participants: ART-Pro is a multisite, multinational trial that will be conducted in two stages, evaluating bpMRI,...

Discrimination Between Benign and Malignant Lesions With Restriction Spectrum Imaging MRI in an Enriched Breast Cancer Screening Cohort

Fri, 14 Feb 2025 00:00:00 +0000

BACKGROUND: Breast cancer screening with dynamic contrast-enhanced MRI (DCE-MRI) is recommended for high-risk women but has limitations, including variable specificity and difficulty in distinguishing cancerous (CL) and high-risk benign lesions (HRBL) from average-risk benign lesions (ARBL). Complementary non-invasive imaging techniques would be useful to improve specificity. PURPOSE: To evaluate the performance of a previously-developed breast-specific diffusion-weighted MRI (DW-MRI) model (BS-RSI3C) to improve discrimination between CL, HRBL, and ARBL in an enriched screening population. STUDY TYPE: Prospective. SUBJECTS: Exactly 187 women, either with mammography screening recommending additional imaging (N = 49) or high-risk individuals undergoing routine breast MRI (N = 138), before the biopsy. FIELD STRENGTH/SEQUENCE: Multishell DW-MRI echo planar imaging sequence with a reduced field of view at 3.0 T. ASSESSMENT: A total of 72 women had at least one biopsied lesion, with...

Ethnic and racial differences in children and young people with respiratory and neurological post-acute sequelae of SARS-CoV-2: an electronic health record-based cohort study from the RECOVER Initiative

Fri, 14 Feb 2025 00:00:00 +0000

Background

Children from racial and ethnic minority groups are at greater risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, but it is unclear whether they have increased risk for post-acute sequelae of SARS-CoV-2 (PASC). Our objectives were to assess whether the risk of respiratory and neurologic PASC differs by race/ethnicity and social drivers of health.

Methods

We conducted a retrospective cohort study of individuals <21 years seeking care at 24 health systems across the U.S, using electronic health record (EHR) data. Our cohort included those with a positive SARS-CoV-2 molecular, serology or antigen test, or with a COVID-19, multisystem inflammatory disease in children, or PASC diagnosis from February 29, 2020 to August 1, 2022. We identified children/youth with at least 2 codes associated with respiratory and neurologic PASC. We measured associations between sociodemographic and clinical characteristics and respiratory and...

Partitioning variance in cortical morphometry into genetic, environmental, and subject-specific components

Fri, 14 Feb 2025 00:00:00 +0000

The relative contributions of genetic variation and experience in shaping the morphology of the adolescent brain are not fully understood. Using longitudinal data from 11,665 subjects in the ABCD Study, we fit vertex-wise variance components including family effects, genetic effects, and subject-level effects using a computationally efficient framework. Variance in cortical thickness and surface area is largely attributable to genetic influence, whereas sulcal depth is primarily explained by subject-level effects. Our results identify areas with heterogeneous distributions of heritability estimates that have not been seen in previous work using data from cortical regions. We discuss the biological importance of subject-specific variance and its implications for environmental influences on cortical development and maturation.

Leveraging the adolescent brain cognitive development study to improve behavioral prediction from neuroimaging in smaller replication samples

Fri, 14 Feb 2025 00:00:00 +0000

Neuroimaging is a popular method to map brain structural and functional patterns to complex human traits. Recently published observations cast doubt upon these prospects, particularly for prediction of cognitive traits from structural and resting state functional magnetic resonance imaging (MRI). We leverage baseline data from thousands of children in the Adolescent Brain Cognitive DevelopmentSM Study to inform the replication sample size required with univariate and multivariate methods across different imaging modalities to detect reproducible brain-behavior associations. We demonstrate that by applying multivariate methods to high-dimensional brain imaging data, we can capture lower dimensional patterns of structural and functional brain architecture that correlate robustly with cognitive phenotypes and are reproducible with only 41 individuals in the replication sample for working memory-related functional MRI, and ~ 100 subjects for structural and resting state MRI. Even...

Early cortical microstructural neurodegeneration in aging is linked to vulnerability to Alzheimer’s disease pathology

Fri, 14 Feb 2025 00:00:00 +0000

Abstract: Background: Early identification of Alzheimer’s disease (AD) risk prior to irreversible brain damage is critical for improving the success of interventions and treatment. Cortical thickness is a macrostructural measure typically used to assess AD neurodegeneration. However, cortical microstructural changes appear to precede macrostructural atrophy and may improve early identification of AD risk. Currently, whether cortical microstructural neurodegeneration in aging is linked to early vulnerability to AD pathophysiology remains unclear in non‐clinical populations, who are precisely the target population for early risk identification. Method: In 194 dementia‐free community‐dwelling adults, we calculated MRI‐derived group‐level brain maps of longitudinal changes in cortical mean diffusivity (microstructure) and cortical thickness (macrostructure) over 5‐6 years (mean age: Time 1=61.82; Time 2=67.48). We obtained PET‐derived group‐level brain maps of stereotypical AD...

Restriction Spectrum Imaging as a quantitative biomarker for prostate cancer with reliable positive predictive value

Fri, 14 Feb 2025 00:00:00 +0000

Abstract Background and Objective Positive predictive value of PI-RADS for clinically significant prostate cancer (csPCa, grade group [GG]≥2) varies widely between institutions and radiologists. The Restriction Spectrum Imaging restriction score (RSIrs) is a metric derived from diffusion MRI that could be an objectively interpretable biomarker for csPCa. Methods In patients scanned for suspected or known csPCa at 7 centers, we calculated patient-level csPCa probability based on maximum RSIrs in the prostate, without relying on subjectively defined lesions. We used area under the ROC curve (AUC) to compare patient-level csPCa detection for RSIrs, ADC, and PI-RADS. Finally, we combined RSIrs with clinical risk factors via multivariable regression, training in a single-center cohort and testing in an independent, multi-center dataset. Key Findings and Limitations Among all patients (n=1892), probability of csPCa increased with higher RSIrs . GG≥4 csPCa was most common in patients...

Robustness of a Restriction Spectrum Imaging (RSI) quantitative MRI biomarker for prostate cancer: assessing for systematic bias due to age, race, ethnicity, prostate volume, medication use, or imaging acquisition parameters

Fri, 14 Feb 2025 00:00:00 +0000

Introduction Prostate multiparametric magnetic resonance imaging (mpMRI) has greatly improved the detection of clinically significant prostate cancer (csPCa). However, the limited number of expert sub-specialist radiologists capable of interpreting conventional prostate mpMRI is a bottleneck for universal access to this healthcare advance. A reliable and reproducible quantitative imaging biomarker could facilitate implementation of accurate prostate MRI at clinical sites with limited experience, thus ensuring more equitable patient care. Restriction Spectrum Imaging restriction score (RSIrs) is an MRI biomarker that has shown the ability to enhance the qualitative and quantitative interpretation of prostate MRI. However, patient-level factors (age, race, ethnicity, prostate volume, and 5-alpha-reductase inhibitor (5-ARI) use) and acquisition-level factors (scanner manufacturer/model and protocol parameters) can affect prostate mpMRI, and their impact on quantitative RSIrs is unknown....

Pleiotropic and sex-specific genetic architecture of circulating metabolic markers

Fri, 14 Feb 2025 00:00:00 +0000

Background: Metabolites in plasma form biosignatures of a range of common complex human diseases. Mapping the genetic architecture and discovering variants with pleiotropic effects across metabolites can reveal underlying mechanisms and potential targets for personalized interventions. Methods: We performed univariate and multivariate genome-wide association studies (GWAS) on the Nightingale panel of 249 circulating plasma metabolic markers, across 207,836 White British UK Biobank participants (mean age 57.4 years, 53.7% female), with replication conducted across 27,509 UK Biobank participants with different ancestries, and 92,661 Estonian Biobank participants (mean age 50.9 years, 65.7% female). We investigated rare variation through whole exome sequencing gene burden tests, quantified genetic architectures through Gaussian mixture modelling, analysed the causal role of body mass index (BMI) through Mendelian randomization, and performed genome-wide interaction analyses with...

Shared Molecular Landscape of Human Brain Structure and Systemic Metabolism

Fri, 14 Feb 2025 00:00:00 +0000

Background: Metabolic processes form the basis of the development, functioning and maintenance of the brain. Despite accumulating evidence of the vital role of metabolism in brain health, no study to date has comprehensively investigated the link between circulating markers of metabolic activity and in vivo brain morphology in the general population. Methods: We performed uni- and multivariate regression on metabolomics and MRI data from 24,940 UK Biobank participants, to estimate the individual and combined associations of 249 circulating metabolic markers with 91 measures of global and regional cortical thickness, surface area and subcortical volume. We investigated similarity of the identified spatial patterns with brain maps of neurotransmitters, and used Mendelian randomization to uncover causal relationships between metabolites and the brain. Results: Intracranial volume and total surface area were highly significantly associated with circulating lipoproteins and...

Early cortical microstructural neurodegeneration in aging is linked to vulnerability to Alzheimer's disease pathology

Fri, 14 Feb 2025 00:00:00 +0000

Are Collagen Protons Visible with the Zero Echo Time (ZTE) Magnetic Resonance Imaging Sequence: A D2O Exchange and Freeze-Drying Study

Thu, 13 Feb 2025 00:00:00 +0000

It is known that ultrashort echo time (UTE) magnetic resonance imaging (MRI) sequences can detect signals from water protons but not collagen protons in short T2 species such as cortical bone and tendons. However, whether collagen protons are visible with the zero echo time (ZTE) MRI sequence is still unclear. In this study, we investigated the potential of the ZTE MRI sequence on a clinical 3T scanner to directly image collagen protons via D₂O exchange and freeze-drying experiments. ZTE and UTE MRI sequences were employed to image fully hydrated bovine cortical bone (n = 10) and human patellar tendon (n = 1) specimens. Then, each specimen was kept in a 30 mL syringe filled with D₂O solution for two days. Fresh D₂O was flushed every 2 h to reach a more complete D₂O-H₂O exchange. Later, the samples were lyophilized for over 40 h and then sealed in tubes. Finally, the samples were brought to room temperature and...

Ethnic and racial differences in children and young people with respiratory and neurological post-acute sequelae of SARS-CoV-2: an electronic health record-based cohort study from the RECOVER Initiative

Thu, 13 Feb 2025 00:00:00 +0000

Background: Children from racial and ethnic minority groups are at greater risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, but it is unclear whether they have increased risk for post-acute sequelae of SARS-CoV-2 (PASC). Our objectives were to assess whether the risk of respiratory and neurologic PASC differs by race/ethnicity and social drivers of health. Methods: We conducted a retrospective cohort study of individuals <21 years seeking care at 24 health systems across the U.S, using electronic health record (EHR) data. Our cohort included those with a positive SARS-CoV-2 molecular, serology or antigen test, or with a COVID-19, multisystem inflammatory disease in children, or PASC diagnosis from February 29, 2020 to August 1, 2022. We identified children/youth with at least 2 codes associated with respiratory and neurologic PASC. We measured associations between sociodemographic and clinical characteristics and respiratory and neurologic PASC...

Comorbidity alters the genetic relationship between anxiety disorders and major depression

Thu, 13 Feb 2025 00:00:00 +0000

Background: Comorbid anxiety disorders (ANX) and major depression (MD) have worse clinical outcomes than either disorder alone. Analysis of genomic data based on comorbidity status may reveal more precise biological pathways and causal relationships with potential clinical implications. We investigated the genetic relationship between ANX and MD with and without mutual comorbidity. Methods: We leveraged data from UK Biobank to perform disorder-specific genome-wide association studies (GWAS) of ANX-only (n=189,422) and MD-only (n=194,339) and generate polygenic risk scores (PRS). The Norwegian Mother, Father, and Child Cohort (MoBa, n = 130,992) served to test the associations of PRS with diagnoses. MD and ANX GWAS, including comorbidities (MD-comorbid and ANX-comorbid), were used for comparison. Genetic correlations were compared by comorbidity status, and Mendelian randomization was employed to assess causal relationships. Results: The MD-only PRS showed a stronger association...

Longitudinal registration of T1-weighted breast MRI: A registration algorithm (FLIRE) and clinical application

Thu, 13 Feb 2025 00:00:00 +0000

PURPOSE: MRI is commonly used to aid breast cancer diagnosis and treatment evaluation. For patients with breast cancer, neoadjuvant chemotherapy aims to reduce the tumor size and extent of surgery necessary. The current clinical standard to measure breast tumor response on MRI uses the longest tumor diameter. Radiologists also account for other tissue properties including tumor contrast or pharmacokinetics in their assessment. Accurate longitudinal image registration of breast tissue is critical to properly compare response to treatment at different timepoints. METHODS: In this study, a deformable Fast Longitudinal Image Registration (FLIRE) algorithm was optimized for breast tissue. FLIRE was then compared to the publicly available software packages with high accuracy (DRAMMS) and fast runtime (Elastix). Patients included in the study received longitudinal T₁_-weighted MRI without fat saturation at two to six timepoints as part of asymptomatic screening (n = 27)...

T27. FEMA-GWAS: FAST AND EFFICIENT MIXED-EFFECTS ALGORITHM FOR DISCOVERY OF GENOME-WIDE AGE-DEPENDENT EFFECTS

Thu, 13 Feb 2025 00:00:00 +0000

T27. FEMA-GWAS: FAST AND EFFICIENT MIXED-EFFECTS ALGORITHM FOR DISCOVERY OF GENOME-WIDE AGE-DEPENDENT EFFECTS

Multivariate patterns linking brain microstructure to temperament and behavior in adolescent eating disorders

Thu, 13 Feb 2025 00:00:00 +0000

Eating disorders (EDs) are multifaceted psychiatric disorders characterized by varying behaviors, traits, and cognitive profiles thought to drive symptom heterogeneity and severity. Non-invasive neuroimaging methods have been critical to elucidate the neurobiological circuitry involved in ED-related behaviors, but often focused on a limited set of regions of interest and/or symptoms. The current study harnesses multivariate methods to map microstructural and morphometric patterns across the entire brain to multiple domains of behavior and symptomatology in patients. Diffusion-weighted images, modeled with restriction spectrum imaging, were analyzed for 91 adolescent patients with an ED and 48 healthy controls. Partial least squares analysis was applied to map 38 behavioral measures (encompassing cognition, temperament, and ED symptoms) to restricted diffusion in white matter tracts and subcortical structures across 65 regions of interest. The first significant latent variable...

From a genomic risk model to clinical trial implementation in a learning health system: the ProGRESS Study

Thu, 13 Feb 2025 00:00:00 +0000

ABSTRACT: Background: As healthcare moves from a one-size-fits-all approach towards precision care, individual risk prediction is an important step in disease prevention and early detection. Biobank-linked healthcare systems can generate knowledge about genomic risk and test the impact of implementing that knowledge in care. Risk-stratified prostate cancer screening is one clinical application that might benefit from such an approach. Methods: We developed a clinical translation pipeline for genomics-informed prostate cancer screening in a national healthcare system. We used data from 585,418 male participants of the Veterans Affairs (VA) Million Veteran Program (MVP), among whom 101,920 self-identify as Black/African-American, to develop and validate the Prostate CAncer integrated Risk Evaluation (P-CARE) model, a prostate cancer risk prediction model based on a polygenic score, family history, and genetic principal components. The model was externally validated in data from...

Precise prostate contours: setting the bar and meticulously evaluating AI performance

Thu, 13 Feb 2025 00:00:00 +0000

Abstract Introduction Evaluation of artificial intelligence (AI) algorithms for prostate segmentation is challenging because ground truth is lacking. We aimed to (1) create a reference standard dataset with precise prostate contours by expert consensus and (2) evaluate various AI tools against this standard. Materials and methods We obtained prostate MRI cases from six institutions from the Quantitative Prostate Imaging Consortium. A panel of four experts (two genitourinary radiologists, two prostate radiation oncologists) meticulously developed consensus prostate segmentations on axial T 2 -weighted series. We evaluated the performance of six AI tools (three commercially available, three academic) using Dice scores, distance from reference contour, and volume error. Results The panel achieved consensus prostate segmentation on each slice of all 68 patient cases included in the reference dataset. We present two patient examples to serve as contouring guides. Depending...

Uncovering population contributions to the extracellular potential in the mouse visual system using Laminar Population Analysis

Thu, 13 Feb 2025 00:00:00 +0000

The local field potential (LFP), the low-frequency part of the extracellular potential, reflects transmembrane currents in the vicinity of the recording electrode. Thought mainly to stem from currents caused by synaptic input, it provides information about neural activity complementary to that of spikes, the output of neurons. However, the many neural sources contributing to the LFP, and likewise the derived current source density (CSD), can often make it challenging to interpret. Efforts to improve its interpretability have included the application of statistical decomposition tools like principal component analysis (PCA) and independent component analysis (ICA) to disentangle the contributions from different neural sources. However, their underlying assumptions of, respectively, orthogonality and statistical independence are not always valid for the various processes or pathways generating LFP. Here, we expand upon and validate a decomposition algorithm named Laminar Population...

Impact of Hip Prostheses on Restriction Spectrum Imaging for Prostate Cancer Detection

Thu, 13 Feb 2025 00:00:00 +0000

Impact of Hip Prostheses on Restriction Spectrum Imaging for Prostate Cancer Detection

Clinical Impact of Contouring Variability for Prostate Cancer Tumor Boost

Thu, 13 Feb 2025 00:00:00 +0000

PURPOSE: The focal radiation therapy (RT) boost technique was shown in a phase III randomized controlled trial (RCT) to improve prostate cancer outcomes without increasing toxicity. This technique relies on the accurate delineation of prostate tumors on MRI. A recent prospective study evaluated radiation oncologists' accuracy when asked to delineate prostate tumors on MRI and demonstrated high variability in tumor contours. We sought to evaluate the impact of contour variability and inaccuracy on predicted clinical outcomes. We hypothesized that radiation oncologists' contour inaccuracies would yield meaningfully worse clinical outcomes. METHODS AND MATERIALS: Forty-five radiation oncologists and 2 expert radiologists contoured prostate tumors on 30 patient cases. Of these cases, those with CT simulation or diagnostic CT available were selected for analysis. A knowledge-based planning model was developed to generate focal RT boost plans for each contour per the RCT protocol. The...

Genomic analysis of intracranial and subcortical brain volumes yields polygenic scores accounting for variation across ancestries

Thu, 13 Feb 2025 00:00:00 +0000

Subcortical brain structures are involved in developmental, psychiatric and neurological disorders. Here we performed genome-wide association studies meta-analyses of intracranial and nine subcortical brain volumes (brainstem, caudate nucleus, putamen, hippocampus, globus pallidus, thalamus, nucleus accumbens, amygdala and the ventral diencephalon) in 74,898 participants of European ancestry. We identified 254 independent loci associated with these brain volumes, explaining up to 35% of phenotypic variance. We observed gene expression in specific neural cell types across differentiation time points, including genes involved in intracellular signaling and brain aging-related processes. Polygenic scores for brain volumes showed predictive ability when applied to individuals of diverse ancestries. We observed causal genetic effects of brain volumes with Parkinson’s disease and attention-deficit/hyperactivity disorder. Findings implicate specific gene expression patterns in brain...

Divergent patterns of genetic overlap between severe mental disorders and metabolic markers

Thu, 13 Feb 2025 00:00:00 +0000

Background Bipolar disorder (BIP), major depressive disorder (MDD) and schizophrenia (SCZ) are severe mental disorders (SMDs), each associated with poor cardiometabolic health. Mapping the genetic relationships of these highly heritable disorders with blood markers of metabolic activity may uncover biological pathways underlying this important shared clinical feature. Methods We charted global genetic overlap of the three SMDs, type 2 diabetes (T2D), coronary artery disease (CAD), and body mass index (BMI) with 249 circulating metabolic markers through linkage disequilibrium score regression and bivariate Gaussian mixture modeling. We estimated causal relationships, functionally annotated shared genetic variants, and investigated enrichment across diverse brain and body tissues. Results All three SMDs had extensive overlap with the metabolic markers. The pattern of genetic correlations was highly similar between MDD, T2D, CAD, and BMI (Spearmans correlation rs>.93), opposite...

Cortical Surface Area Profile Mediates Effects of Childhood Disadvantage on Later-Life General Cognitive Ability

Thu, 13 Feb 2025 00:00:00 +0000

OBJECTIVES: Childhood disadvantage is associated with lower general cognitive ability (GCA) and brain structural differences in midlife and older adulthood. However, the neuroanatomical mechanisms underlying childhood disadvantage effects on later-life GCA remain poorly understood. Although total surface area (SA) has been linked to lifespan GCA differences, total SA does not capture the nonuniform nature of childhood disadvantage effects on neuroanatomy, which varies across unimodal and transmodal cortices. Here, we examined whether cortical SA profile-the extent to which the spatial patterning of SA deviates from the normative unimodal-transmodal cortical organization-is a mediator of childhood disadvantage effects on later-life GCA. METHODS: In 477 community-dwelling men aged 56-72 years old, childhood disadvantage index was derived from four indicators of disadvantages and GCA was assessed using a standardized test. Cortical SA was obtained from structural magnetic resonance...

Deep learning AI and Restriction Spectrum Imaging for patient-level detection of clinically significant prostate cancer on MRI

Thu, 13 Feb 2025 00:00:00 +0000

Abstract Background The Prostate Imaging Reporting & Data System (PI-RADS), based on multiparametric MRI (mpMRI), is widely used for the detection of clinically significant prostate cancer (csPCa, Gleason Grade Group (GG≥2)). However, its diagnostic accuracy can be impacted by variability in interpretation. Restriction Spectrum Imaging (RSI), an advanced diffusion-weighted technique, offers a standardized, quantitative approach for detecting csPCa, potentially enhancing diagnostic consistency and performing comparably to expert-level assessments. Purpose To evaluate whether combining maximum RSI-derived restriction scores (RSIrs-max) with deep learning (DL) models can enhance patient-level detection of csPCa compared to using PI-RADS or RSIrs-max alone. Materials and Methods Data from 1,892 patients across seven institutions were analyzed, selected based on MRI results and biopsy-confirmed diagnoses. Two deep learning architectures, 3D-DenseNet and 3D-DenseNet+RSI (incorporating...

Quality over quantity: powering neuroimaging samples in psychiatry

Thu, 13 Feb 2025 00:00:00 +0000

Neuroimaging has been widely adopted in psychiatric research, with hopes that these non-invasive methods will provide important clues to the underpinnings and prediction of various mental health symptoms and outcomes. However, the translational impact of neuroimaging has not yet reached its promise, despite the plethora of computational methods, tools, and datasets at our disposal. Some have lamented that too many psychiatric neuroimaging studies have been underpowered with respect to sample size. In this review, we encourage this discourse to shift from a focus on sheer increases in sample size to more thoughtful choices surrounding experimental study designs. We propose considerations at multiple decision points throughout the study design, data modeling and analysis process that may help researchers working in psychiatric neuroimaging boost power for their research questions of interest without necessarily increasing sample size. We also provide suggestions for leveraging multiple...

Charting the shared genetic architecture of Alzheimer's disease, cognition, and educational attainment, and associations with brain development

Thu, 13 Feb 2025 00:00:00 +0000

The observation that the risk of developing Alzheimer's disease is reduced in individuals with high premorbid cognitive functioning, higher educational attainment, and occupational status has led to the 'cognitive reserve' hypothesis. This hypothesis suggests that individuals with greater cognitive reserve can tolerate a more significant burden of neuropathological changes before the onset of cognitive decline. The underpinnings of cognitive reserve remain poorly understood, although a shared genetic basis between measures of cognitive reserve and Alzheimer's disease has been suggested. Using the largest samples to date and novel statistical tools, we aimed to investigate shared genetic variants between Alzheimer's disease, and measures of cognitive reserve; cognition and educational attainment to identify molecular and neurobiological foundations. We applied the causal mixture model (MiXeR) to estimate the number of trait-influencing variants shared between Alzheimer's disease,...

Leveraging the Genetics of Psychiatric Disorders to Prioritize Potential Drug Targets and Compounds

Thu, 13 Feb 2025 00:00:00 +0000

Background: Genetics has the potential to inform biologically relevant drug treatment and repurposing which may ultimately improve patient care. In this study, we combine methods which leverage the genetics of psychiatric disorders to prioritize potential drug targets and compounds. Methods: We used the largest available genome-wide association studies, in European ancestry, of four psychiatric disorders [i.e., attention deficit hyperactivity disorder (ADHD), bipolar disorder, depression, and schizophrenia] along with genes encoding drug targets. With this data, we conducted drug enrichment analyses incorporating the novel and biologically specific GSA-MiXeR tool. We then conducted a series of molecular trait analyses using large-scale transcriptomic and proteomic datasets sampled from brain and blood tissue. This included the novel use of the UK Biobank proteomic data for a proteome-wide association study of psychiatric disorders. With the accumulated evidence, we prioritize...

An accelerated PETALUTE MRI sequence for in vivo quantification of sodium content in human articular cartilage at 3T

Tue, 11 Feb 2025 00:00:00 +0000

ObjectiveIn this work, we evaluate the sodium magnetic resonance imaging (MRI) capabilities of a three-dimensional (3D) dual-echo ultrashort echo time (UTE) sequence with a novel rosette petal trajectory (PETALUTE), in comparison to the 3D density-adapted (DA) radial spokes UTE sequence in human articular cartilage in the knee.Materials and methodsWe scanned five healthy subjects using a 3D dual-echo PETALUTE acquisition and two comparable implementations of 3D DA-radial spokes acquisitions, one matching the number of k-space projections (Radial – Matched Spokes) and the other matching the total number of samples (Radial – Matched Samples) acquired in k-space.ResultsThe PETALUTE acquisition enabled equivalent sodium quantification in articular cartilage volumes of interest (168.8 ± 29.9 mM, mean ± standard deviation) to those derived from the 3D radial acquisitions (171.62 ± 28.7 mM and 149.8 ± 22.2 mM, respectively). We achieved a 41% shorter scan time of 2:06...

Psychiatric disorders and brain white matter exhibit genetic overlap implicating developmental and neural cell biology

Tue, 11 Feb 2025 00:00:00 +0000

Improved understanding of the shared genetic architecture between psychiatric disorders and brain white matter may provide mechanistic insights for observed phenotypic associations. Our objective is to characterize the shared genetic architecture of bipolar disorder (BD), major depression (MD), and schizophrenia (SZ) with white matter fractional anisotropy (FA) and identify shared genetic loci to uncover biological underpinnings. We used genome-wide association study (GWAS) summary statistics for BD (n = 413,466), MD (n = 420,359), SZ (n = 320,404), and white matter FA (n = 33,292) to uncover the genetic architecture (i.e., polygenicity and discoverability) of each phenotype and their genetic overlap (i.e., genetic correlations, overlapping trait-influencing variants, and shared loci). This revealed that BD, MD, and SZ are at least 7-times more polygenic and less genetically discoverable than average FA. Even in the presence of weak genetic correlations (range = −0.05 to −0.09),...

How Real-World Data Can Facilitate the Development of Precision Medicine Treatment in Psychiatry

Tue, 11 Feb 2025 00:00:00 +0000

Precision medicine has the ambition to improve treatment response and clinical outcomes through patient stratification and holds great potential for the treatment of mental disorders. However, several important factors are needed to transform current practice into a precision psychiatry framework. Most important are 1) the generation of accessible large real-world training and test data including genomic data integrated from multiple sources, 2) the development and validation of advanced analytical tools for stratification and prediction, and 3) the development of clinically useful management platforms for patient monitoring that can be integrated into health care systems in real-life settings. This narrative review summarizes strategies for obtaining the key elements-well-powered samples from large biobanks integrated with electronic health records and health registry data using novel artificial intelligence algorithms-to predict outcomes in severe mental disorders and translate...

Early Cortical Microstructural Changes in Aging Are Linked to Vulnerability to Alzheimer’s Disease Pathology

Mon, 10 Feb 2025 00:00:00 +0000

BACKGROUND: Early identification of Alzheimer's disease (AD) risk is critical for improving treatment success. Cortical thickness is a macrostructural measure used to assess neurodegeneration in AD. However, cortical microstructural changes appear to precede macrostructural atrophy and may improve early risk identification. Currently, whether cortical microstructural changes in aging are linked to vulnerability to AD pathophysiology remains unclear in nonclinical populations, who are precisely the target for early risk identification. METHODS: In 194 adults, we calculated magnetic resonance imaging-derived maps of changes in cortical mean diffusivity (microstructure) and cortical thickness (macrostructure) over 5 to 6 years (mean age: time 1 = 61.82 years; time 2 = 67.48 years). Episodic memory was assessed using 3 well-established tests. We obtained positron emission tomography-derived maps of AD pathology deposition (amyloid-β, tau) and neurotransmitter receptors (cholinergic,...

Characterizing the Shared Genetic Underpinnings of Schizophrenia and Cardiovascular Disease Risk Factors

Mon, 10 Feb 2025 00:00:00 +0000

OBJECTIVE: Schizophrenia is associated with increased risk of cardiovascular disease (CVD), although there is variation in risk among individuals. There are indications of shared genetic etiology between schizophrenia and CVD, but the nature of the overlap remains unclear. The aim of this study was to fill this gap in knowledge. METHODS: Overlapping genetic architectures between schizophrenia and CVD risk factors were assessed by analyzing recent genome-wide association study (GWAS) results. The bivariate causal mixture model (MiXeR) was applied to estimate the number of shared variants and the conjunctional false discovery rate (conjFDR) approach was used to pinpoint specific shared loci. RESULTS: Extensive genetic overlap was found between schizophrenia and CVD risk factors, particularly smoking initiation (N=8.6K variants) and body mass index (BMI) (N=8.1K variants). Several specific shared loci were detected between schizophrenia and BMI (N=304), waist-to-hip ratio (N=193),...

Improved functional mapping of complex trait heritability with GSA-MiXeR implicates biologically specific gene sets

Mon, 10 Feb 2025 00:00:00 +0000

While genome-wide association studies are increasingly successful in discovering genomic loci associated with complex human traits and disorders, the biological interpretation of these findings remains challenging. Here we developed the GSA-MiXeR analytical tool for gene set analysis (GSA), which fits a model for the heritability of individual genes, accounting for linkage disequilibrium across variants and allowing the quantification of partitioned heritability and fold enrichment for small gene sets. We validated the method using extensive simulations and sensitivity analyses. When applied to a diverse selection of complex traits and disorders, including schizophrenia, GSA-MiXeR prioritizes gene sets with greater biological specificity compared to standard GSA approaches, implicating voltage-gated calcium channel function and dopaminergic signaling for schizophrenia. Such biologically relevant gene sets, often with fewer than ten genes, are more likely to provide insights into...

Amyloid-β predominant Alzheimer’s disease neuropathologic change

Wed, 5 Feb 2025 00:00:00 +0000

Different subsets of Alzheimer's disease neuropathologic change (ADNC), including the intriguing set of individuals with severe/widespread amyloid-β (Aβ) plaques but no/mild tau tangles [Aβ-predominant (AP)-ADNC], may have distinct genetic and clinical features. Analysing National Alzheimer's Coordinating Center data, we stratified 1187 participants into AP-ADNC (n = 95), low Braak primary age-related tauopathy (PART; n = 185), typical-ADNC (n = 832) and high-Braak PART (n = 75). AP-ADNC differed in some clinical features and genetic polymorphisms in the APOE, SNX1, WNT3/MAPT and IGH genes. We conclude that AP-ADNC differs from classical ADNC with implications for in vivo studies.

Advanced Restriction Imaging and Reconstruction Technology for Prostate Magnetic Resonance Imaging (ART-Pro): A Study Protocol for a Multicenter, Multinational Trial Evaluating Biparametric Magnetic Resonance Imaging and Advanced, Quantitative Diffusion Magnetic Resonance Imaging for the Detection of Prostate Cancer

Fri, 31 Jan 2025 00:00:00 +0000

Multiparametric magnetic resonance imaging (mpMRI) is strongly recommended by current clinical guidelines for improved detection of clinically significant prostate cancer (csPCa). However, the major limitations are the need for intravenous (IV) contrast and dependence on reader expertise. Efforts to address these issues include use of biparametric magnetic resonance imaging (bpMRI) and advanced, quantitative magnetic resonance imaging (MRI) techniques. One such advanced technique is the Restriction Spectrum Imaging restriction score (RSIrs), an imaging biomarker that has been shown to improve quantitative accuracy of patient-level csPCa detection. Advanced Restriction imaging and reconstruction Technology for Prostate MRI (ART-Pro) is a multisite, multinational trial that aims to evaluate whether IV contrast can be avoided in the setting of standardized, state-of-the-art image acquisition, with or without addition of RSIrs. Additionally, RSIrs will be evaluated as a stand-alone,...

Robust, fully-automated assessment of cerebral perivascular spaces and white matter lesions: a multicentre MRI longitudinal study of their evolution and association with risk of dementia and accelerated brain atrophy

Thu, 30 Jan 2025 00:00:00 +0000

BACKGROUND: Perivascular spaces (PVS) on brain MRI are surrogates for small parenchymal blood vessels and their perivascular compartment, and may relate to brain health. However, it is unknown whether PVS can predict dementia risk and brain atrophy trajectories in participants without dementia, as longitudinal studies on PVS are scarce and current methods for PVS assessment lack robustness and inter-scanner reproducibility. METHODS: We developed a robust algorithm to automatically assess PVS count and size on clinical MRI, and investigated 1) their relationship with dementia risk and brain atrophy in participants without dementia, 2) their longitudinal evolution, and 3) their potential use as a screening tool in simulated clinical trials. We analysed 46,478 clinical measurements of cognitive functioning and 20,845 brain MRI scans from 10,004 participants (71.1 ± 9.7 years-old, 56.6% women) from three publicly available observational studies on ageing and dementia (the...

Utility of quantitative measurement of T2 using restriction spectrum imaging for detection of clinically significant prostate cancer

Fri, 17 Jan 2025 00:00:00 +0000

The Restriction Spectrum Imaging restriction score (RSIrs) has been shown to improve the accuracy for diagnosis of clinically significant prostate cancer (csPCa) compared to standard DWI. Both diffusion and T2 properties of prostate tissue contribute to the signal measured in DWI, and studies have demonstrated that each may be valuable for distinguishing csPCa from benign tissue. The purpose of this retrospective study was to (1) determine whether prostate T2 varies across RSI compartments and in the presence of csPCa, and (2) evaluate whether csPCa detection with RSIrs is improved by acquiring multiple scans at different TEs to measure compartmental T2 (cT2). Data includes two cohorts scanned for csPCa with 3T multi-b-value diffusion-weighted sequences acquired at multiple TEs. cT2 values were computed from multi-TE RSI data and compared by compartment. CsPCa detection was compared between RSIrs and a logistic regression model (LRM) to predict the probability of csPCa using cT2...