Radiographics : a review publication of the Radiological Society of North America, Inc
-
Most pediatric chest diseases are adequately evaluated with chest radiography. However, when chest radiography does not allow identification of the location and nature of an area of increased opacity, ultrasonography (US) can help establish the diagnosis. US may be helpful in evaluation of persistent or unusual areas of increased opacity in the peripheral lung, pleural abnormalities, and mediastinal widening; US is particularly useful in patients with complete opacification of a hemithorax at radiography. ⋯ Computed tomography and magnetic resonance imaging are superior to US in evaluation of the mediastinum, but US is a reasonable alternative in certain situations (eg, to avoid unnecessary investigation of a normal thymus simulating a mediastinal mass). In cases of chest wall lesions, US may enable localization of the site of origin to soft tissues or an extrapleural intrathoracic location. Osseous involvement, particularly rib involvement, is easily evaluated with US.
-
Ischemic bowel disease represents a broad spectrum of diseases with various clinical and radiologic manifestations, which range from localized transient ischemia to catastrophic necrosis of the gastrointestinal tract. The primary causes of insufficient blood flow to the intestine are diverse and include thromboembolism, nonocclusive causes, bowel obstruction, neoplasms, vasculitis, abdominal inflammatory conditions, trauma, chemotherapy, radiation, and corrosive injury. Computed tomography (CT) or magnetic resonance (MR) imaging can demonstrate the ischemic bowel segment and may be helpful in determining the primary cause. ⋯ However, regardless of the primary cause, the imaging findings of bowel ischemia are similar. Furthermore, the bowel changes simulate inflammatory or neoplastic conditions. Understanding the pathogenesis of various conditions leading to mesenteric ischemia helps the radiologist recognize ischemic bowel disease and avoid delayed diagnosis, unnecessary surgery, or less than optimal management.
-
Transfemoral placement of an endovascular stent-graft is increasingly be-ing used as an alternative to surgical repair in the treatment of abdominal aortic aneurysm, especially in high-risk patients. However, complications frequently occur after stent-graft placement. Helical computed tomographic (CT) angiography is a fast, minimally invasive procedure that is quickly becoming the imaging modality of choice for assessment of these complications. ⋯ Findings included both graft-related (n = 4) and non-graft-related (n = 3) leaks, thrombosis of a graft limb (n = 3), distal migration of the stent-graft (n = 5), angulation of bifurcated stent-grafts distal to the main graft (n = 6), shrinkage of the abdominal aortic aneurysm (n = 7), enlargement of the aneurysm with secondary graft-related leaks (n = 2), and an aortoduodenal fistula (n = 1). Helical CT angiography can depict complications that develop after treatment of abdominal aortic aneurysms with endovascular stent-grafts. Long-term follow-up is required to determine the full spectrum and frequency of complications that may develop after initially successful repair.