Imaging assessment of congenital and acquired abnormalities of the portal venous system.

Abnormalities of the portal venous system are a heterogeneous group of conditions that can cause substantial morbidity and mortality and may lead to complications during surgery or percutaneous interventions involving the portal venous system. High-resolution computed tomography, ultrasonography, and magnetic resonance imaging permit a comprehensive, noninvasive evaluation of the portal venous system, enabling the detection of both structural and functional abnormalities. However, an understanding of the embryologic development of the normal portal venous anatomy and anatomic variants is essential to accurately interpret the imaging findings. Knowledge of the characteristic appearances of abnormalities of the portal venous system allows a more confident diagnosis, permitting timely treatment and more informed guidance of surgical procedures and percutaneous interventions, which may lead to an improved outcome.

Clinical Images. An unusual case of appendicitis.

Situs inversus may be identified as an incidental finding when investigating abdominal pain in the acute emergency setting. We report a case of a 46-year-old man who presented with left-sided acute appendicitis on a background of situs inversus. The clinical presentation was left lower-quadrant pain. Clinically, the diagnosis of diverticulitis was made until review of plain-film imaging raised the possibility of situs inversus, and thus appendicitis. Cross-sectional imaging studies and laparoscopy confirmed the diagnosis of acute left-sided appendicitis. He underwent laparoscopic appendectomy with an uncomplicated postoperative course.

Infected (mycotic) aneurysms: spectrum of imaging appearances and management.

Infected aneurysms are uncommon. The aorta, peripheral arteries, cerebral arteries, and visceral arteries are involved in descending order of frequency. Staphylococcus and Streptococcus species are the most common causative pathogens. Early clinical diagnosis of infected aneurysms is challenging owing to their protean manifestations. Clinically apparent infected aneurysms are often at an advanced stage of development or are associated with complications, such as rupture. Nontreatment or delayed treatment of infected aneurysms often has a poor outcome, with high morbidity and mortality from fulminant sepsis or hemorrhage. Current state-of-the-art imaging modalities, such as multidetector computed tomography and magnetic resonance imaging, have replaced conventional angiography as minimally invasive techniques for detection of infected aneurysms in clinically suspected cases, as well as characterization of infected aneurysms and vascular mapping for treatment planning in confirmed cases. Doppler ultrasonography allows noninvasive assessment for infected aneurysms in the peripheral arteries. Imaging features of infected aneurysms include a lobulated vascular mass, an indistinct irregular arterial wall, perianeurysmal edema, and a perianeurysmal soft-tissue mass. Perianeurysmal gas, aneurysmal thrombosis, aneurysmal wall calcification, and disrupted arterial calcification at the site of the infected aneurysm are uncommon findings. Imaging-guided endovascular stent-graft repair and embolotherapy can be performed in select cases instead of open surgery. Familiarity with the imaging appearances of infected aneurysms should alert the radiologist to the diagnosis and permit timely treatment, which may include endovascular techniques.

Prospective assessment of magnetic resonance cholangiopancreatography for noninvasive imaging of the biliary tree.

BACKGROUND: Traditionally, ERCP has been the only reliable method for imaging the biliary tree, but it is invasive and carries a risk of complications. Magnetic resonance cholangiopancreatography (MRCP) is a noninvasive method for imaging the biliary tree. The aim of this study was to prospectively assess the accuracy of MRCP in a large number of patients. METHODS: Consecutive patients referred to a teaching hospital for ERCP were eligible for study entry. MRCP was performed within 24 hours before ERCP. MRCP findings were compared with ERCP findings or, when the initial ERCP was unsuccessful, with results of repeat ERCP, percutaneous transhepatic cholangiography, or surgery. RESULTS: One hundred forty-six patients underwent 149 ERCP/MRCP procedures, of which 129 were evaluable with successful MRCP and ERCP or an ERCP-equivalent study. Diagnoses included choledocholithiasis in 46 and biliary stricture in 12 patients. The sensitivity, specificity, positive, and negative predictive values for MRCP in the diagnosis of choledocholithiasis were 97.9%, 89.0%, 83.6%, and 98.6%, respectively. All 12 strictures were diagnosed by MRCP (sensitivity 100%, specificity 99.1%). CONCLUSIONS: MRCP is an accurate, noninvasive alternative to ERCP for imaging the biliary tree. Choledocholithiasis and biliary strictures can be reliably diagnosed or excluded by MRCP. MRCP should be used increasingly in patients with suspected biliary obstruction to select those who require a therapeutic procedure.