A Spectrum of Entities That May Mimic Abdominopelvic Abscesses Requiring Image-guided Drainage.

A variety of entities may mimic drainable abscesses. This can lead to misdiagnosis of these entities, unnecessary percutaneous placement of a pigtail drainage catheter, other complications, and delay in appropriate treatment of the patient. Types of entities that may mimic drainable abscesses include neoplasms (lymphoma, gallbladder cancer, gastrointestinal stromal tumor, ovarian cancer, mesenteric fibromatosis, ruptured mature cystic teratoma, recurrent malignancy in a surgical bed), ischemia/infarction (liquefactive infarction of the spleen, infarcted splenule), diverticula (calyceal, Meckel, and giant colonic diverticula), and congenital variants (obstructed duplicated collecting system). Postoperative changes, including expected anatomy after urinary diversion or Roux-en-Y gastric bypass and small bowel resection, may also pose a diagnostic challenge. Nonpyogenic infections (Mycobacterium tuberculosis, Mycobacterium avium complex, echinococcal cysts) and inflammatory conditions such as xanthogranulomatous pyelonephritis and gossypiboma could also be misinterpreted as drainable fluid collections. Appropriate recognition of these entities is essential for optimal patient care. This article exposes radiologists to a variety of entities for which percutaneous drainage may be requested, but is not indicated, and highlights important imaging findings associated with these entities to facilitate greater diagnostic accuracy and treatment in their practice. ©RSNA, 2018.

Imaging following bariatric surgery: roux-en-Y gastric bypass, laparoscopic adjustable gastric banding and sleeve gastrectomy.

Morbid obesity is an increasing health problem, and bariatric surgery is a popular treatment option. Radiologists must be familiar with performing and interpreting studies in this patient population. The typical post-operative findings of the Roux-en-Y gastric bypass (RYGB), laparoscopic adjustable gastric banding (LAGB) and sleeve gastrectomy (SG) procedures on upper gastrointestinal (UGI) series and computerized tomography (CT) are presented. An overview of the potential complications is provided in addition to a description of potential pitfalls in interpreting these studies.

Diagnosis of typical and atypical transition zone prostate cancer and its mimics at multiparametric prostate MRI.

Many of the current clinical screening methods for prostate cancer (PCa) such as prostate-specific antigen (PSA) testing or transrectal ultrasound-guided prostate biopsy lack sensitivity and specificity for diagnosis of PCa of the transition zone (TZ). Recent technical advances in multiparametric-MRI have markedly improved detection of PCa of the TZ. However, there are many diagnostic challenges that we still encounter in our daily practice that compromise the accuracy of the diagnosis. By performing both MRI-guided and ultrasound/MRI fusion-guided biopsies, we have gained extensive experience in the diagnosis of PCa of the TZ. Biopsy-proven examples including but not limited to typical and atypical PCa of the TZ as well as a wide variety of its mimics will be presented. Recognition of the MR features of typical and atypical PCa of the TZ and its mimics on multiparametric-MRI along with findings that help to differentiate these mimics from PCa is important in establishing an accurate diagnosis and in guiding clinical management.