The shoulder joint is a complex array of muscles, tendons, and capsuloligamentous structures that has the greatest freedom of motion of any joint in the body. Acute (<2 weeks) shoulder pain can be attributable to structures related to the glenohumeral articulation and joint capsule, rotator cuff, acromioclavicular joint, and scapula. The foundation for investigation of acute shoulder pain is radiography. Magnetic resonance imaging is the procedure of choice for the evaluation of occult fractures and the shoulder soft tissues. Ultrasound, with appropriate local expertise, is an excellent evaluation of the rotator cuff, long head of the biceps tendon, and interventional procedures. Fluoroscopy is an excellent modality to guide interventional procedures. Computed tomography is an excellent modality for characterizing complex shoulder fractures. Computed tomographic arthrography or fluoroscopic arthrography may be alternatives in patients for whom MR arthrography is contraindicated. A multimodal approach may be required to accurately assess shoulder pathology. The ACR Appropriateness Criteria® are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. © 2011 American College of Radiology.

Appropriate imaging modalities for screening, staging, and surveillance of patients with suspected and documented metastatic disease to bone include 99mTc bone scanning, MRI, CT, radiography, and 2-[18F]fluoro-2-deoxyglucose-PET. Clinical scenarios reviewed include asymptomatic stage 1 breast carcinoma, symptomatic stage 2 breast carcinoma, abnormal bone scan results with breast carcinoma, pathologic fracture with known metastatic breast carcinoma, asymptomatic well-differentiated and poorly differentiated prostate carcinoma, vertebral fracture with history of malignancy, non-small-cell lung carcinoma staging, symptomatic multiple myeloma, osteosarcoma staging and surveillance, and suspected bone metastasis in a pregnant patient. No single imaging modality is consistently best for the assessment of metastatic bone disease across all tumor types and clinical situations. In some cases, no imaging is indicated. The recommendations contained herein are the result of evidence-based consensus by the ACR Appropriateness Criteria® Expert Panel on Musculoskeletal Radiology. © 2010 American College of Radiology.