Postoperative Shoulder Imaging: Rotator Cuff, Labrum, and Biceps Tendon.

Imaging interpretation of the postoperative shoulder is a challenging and difficult task for both the radiologist and the orthopedic surgeon. The increasing number of shoulder rotator cuff, labrum, and biceps tendon repairs performed in the United States also makes this task a frequent occurrence. Whether treatment is surgical or conservative, imaging plays a crucial role in patient care. Many imaging findings can be used to predict prognosis and functional outcomes, ultimately affecting treatment. In addition, evolving surgical techniques alter the normal anatomy and imaging appearance of the shoulder such that accepted findings proved to be pathologic in the preoperative setting cannot be as readily described as pathologic after surgery. An understanding of common surgical procedures of the shoulder can aid in recognizing normal expected postoperative findings and discerning common complications. Although magnetic resonance (MR) imaging and MR arthrography are widely used, implementing a multimodality imaging approach for evaluation of the postoperative shoulder can provide additional imaging information that may be decisive and vital to diagnosis. The high spatial resolution of both computed tomography with arthrography and ultrasonography makes them additional modalities to consider, especially when dealing with metal artifact. To provide an accurate radiologic interpretation of high clinical value, radiologists should approach the postoperative shoulder comprehensively with knowledge of the anatomy, surgical techniques and complications, clinical outcomes, and imaging pitfalls. ©RSNA, 2016.

Pneumothorax in the Supine Patient: Subtle Radiographic Signs.

Routine posteroanterior chest radiographs and computed tomography scans are more sensitive for detecting pneumothoraces than anteroposterior chest radiographs. However, supine chest radiographs are commonly performed as part of the initial and routine assessment of trauma and critically ill patients. Rates of occult pneumothorax can be as high as 50% and have a significant impact in the mortality of these patients; thus, a prompt diagnosis of this entity is important. This pictorial essay will illustrate the pleural anatomy, explain the distribution of air within the pleural space in the supine position, and review the radiologic findings that characterize this entity.