UC Berkeley

Cardiovascular Disease (CVD) is the leading cause of death in the United States. CVD is

caused by a buildup of plaque in the blood vessels of the heart and brain. CVD is comorbid

with Peripheral Vascular Disease (PVD), which is a buildup of plaque in the extremities

and organs below the stomach. Medical imaging is a clinically indispensable tool for diagnosing CVD and PVD, as well as guiding real-time interventional procedures. Currently,

the two main procedures for diagnosing CVD and PVD are X-Ray and CT angiography,

both of which rely on injection of iodinated contrast agents. However, about 25% of patient

undergoing these procedures suer from Chronic Kidney Disease (CKD). For this patient

subpopulation, iodinated contrast agents are risky and can lead to complete kidney failure.

Physicians risk damaging patients' kidneys in order to alleviate the more imminent threat of

death from a heart attack. Hence, an open challenge remains to develop a safer diagnostic

angiography method that could match current methods in resolution, contrast, and speed.

Here we introduce and develop two new imaging methods for imaging patients with CKD.

The rst method is MR Saline Angiography, an alternative Magnetic Resonance (MR) based

angiographic method for coronary imaging. In combination with the inherent resolution and

speed of traditional MR methods, MR Saline Angiography has the advantage of utilizing

saline as a safe contrast agent. This approach is an improvement upon the commonly used

Gadolinium-based contrast agent that is also toxic to patients with CKD. Using a novel

electromagnetically shielded catheter and a tailored pulse sequence, we have demonstrated

that MR Saline Angiography is a feasible alternative for imaging coronary arteries. The second method is Magnetic Particle Imaging (MPI), a tracer imaging modality, which images

Superparamagnetic Iron Oxide nanoparticles. MPI is an emerging imaging technique with

possible applications in angiography as well as targeted and non-targeted tumor imaging,

hyperthermia, perufsion, cell tracking and targeted drug delivery. Here we study the feasibility

of MPI as an angiographic imaging method by looking at short-term biodistribution

and long-term iron clearance for two most common MPI tracers.