Computed tomography colonography is a minimally invasive method for screening for polyps and colorectal cancer, with extremely unusual complications, increasingly used in the clinical practice. In the last decade, developments in bowel preparation, imaging, and in the training of investigators have determined a significant increase in the method sensitivity. Images interpretation is accomplished through a combined analysis of two-dimensional source images and several types of three-dimensional renderings, with sensitivity around 96% in the detection of lesions with dimensions equal or greater than 10 mm in size, when analyzed by experienced radiologists. The present pictorial essay includes examples of diseases and pseudolesions most frequently observed in this type of imaging study. The authors present examples of flat and polypoid lesions, benign and malignant lesions, diverticular disease of the colon, among other conditions, as well as pseudolesions, including those related to inappropriate bowel preparation and misinterpretation.

Keywords: Colonography; Computed tomography; Colorectal neoplasm; Colonic polyps.

The present article is aimed at describing the key findings of ovarian torsion at computed tomography and magnetic resonance imaging. Two investigators have consensually selected and analyzed magnetic resonance imaging and computed tomography images acquired in the period from January 2010 to December 2011 of patients with proven acute abdominal pain resulting from ovarian torsion, highlighting the main imaging findings. The increasing role of computed tomography and magnetic resonance imaging in the assessment of patient with acute abdomen of gynecological origin demands radiologists' familiarity with the imaging findings related to the main causes of such condition through the use of these diagnostic tools in association with ultrasonography.

Keywords: Acute abdomen; Adnexal diseases; Ovarian torsion; Computed tomography; Magnetic resonance imaging.

OBJECTIVE: To determine the prevalence of liver cysts and hemangiomas in the general population and in cirrhotic patients. MATERIALS AND METHODS: Retrospective, observational, and cross-sectional study selecting consecutive magnetic resonance imaging studies performed in the period from February to July 2011. A total of 303 patients (187 women and 116 men) with mean age of 53.3 years were included in the present study. Patients with previously known liver lesions were excluded. The images were consensually analyzed by two observers in the search for simple liver cysts and typical liver hemangiomas, according to universally accepted imaging criteria. Lesions prevalence, diameters and location were determined in both cirrhotic and non-cirrhotic individuals. RESULTS: The authors observed prevalence of 8.6% for hemangiomas and 14.5% for simple cysts. No statistically significant difference was observed in relation to prevalence of hemangiomas and cysts among cirrhotic and non-cirrhotic patients (p = 0.954; p = 0.472). CONCLUSION: In the present study, the prevalence of cysts and hemangiomas was higher than the prevalence reported by autopsy series. No influence of cirrhosis was observed on the prevalence and appearance of such incidental lesions.

Keywords: Hemangioma; Cysts; Magnetic resonance imaging; Prevalence; Liver.

Most tumors of the biliary tract are too small to have specific imaging characteristics or for percutaneous puncture to provide sufficient material for diagnosis. Percutaneous transhepatic biliary drainage, in addition to being a well-established technique in the treatment of obstructive jaundice, provides adequate access for sampling obstructive lesions. In cases of biliary lesions, percutaneous transhepatic biopsy of the biliary tract has proven to be a useful diagnostic technique, with a reported accuracy of over 90% at some referral centers.

Keywords: Bile duct neoplasms; Biliary tract; Biopsy/methods; Biopsy, needle/methods; Cholangiography.

Objective: To analyze the results obtained with a modified antegrade double J catheter insertion (JJ stenting) technique in patients with urinary tract obstruction due to malignancy. Materials and Methods: This was a retrospective analysis of data collected from patients undergoing antegrade JJ stenting for malignant ureteral obstruction in the interventional radiology department of our institution between March 1, 2017 and May 31, 2019. Results: Antegrade JJ stenting was performed in 32 patients (20 women and 12 men). The mean age was 66.2 years among the females and 61.5 years among the males. A total of 53 antegrade JJ stenting procedures were performed. The procedure was successful in 50 cases and failed in 3 (due to migration of the double J catheter in 2 and due to technical failure in 1). Complications occurred in 3 patients (low back pain, in 1, subcapsular hematoma, in 1, and pyelonephritis, in 1). The procedure time ranged from 14 min to 55 min. Conclusion: In patients with ureteral obstruction due to malignancy, antegrade JJ stenting is safe and effective. The technique selected in our study is easily reproduced and can be performed by a trained professional.

Keywords: Urinary catheterization/instrumentation; Stents; Ureteral obstruction; Radiology, interventional; Urologic neoplasms.

OBJECTIVE: To investigate long-term results of biliary biopsy performed with transluminal forceps in the setting of metastatic biliary involvement. MATERIALS AND METHODS: Between September 2014 and June 2019, 25 patients—18 males (72%)—with a mean age of 65 ± 15 years, underwent 26 biliary biopsy procedures with a dedicated forceps system. All patients presented with obstructive jaundice that was suspected of being malignant and underwent pre-procedural magnetic resonance cholangiopancreatography. The biopsies were performed during percutaneous placement of an internal-external biliary drainage catheter, under fluoroscopic guidance. RESULTS: The technical success rate was 96% (corresponding to 25 of the 26 procedures). The histological diagnosis was inflammatory biliary stricture in five cases, pancreatic adenocarcinoma in six, liver metastases from colorectal cancer in eight, and hepatocellular carcinoma in three, the biliary mucosa being categorized as normal in three cases. In one case, the sample was considered insufficient and the procedure was successfully repeated, after which a diagnosis of pancreatic adenocarcinoma was made. Over a follow-up period of 6–48 months, there were five false-negative results: two findings of inflammatory biliary stricture were later identified as liver metastases from breast and gastric cancer, respectively; and all three patients in which the biliary mucosa was categorized as normal were subsequently diagnosed with metastatic hilar lymph nodes. The procedure was found to have a sensitivity of 77%, a specificity of 100%, and an overall accuracy of 80%. The complication rate was 11.5% (mild, transient hemobilia occurring in three cases). CONCLUSION: Percutaneous transluminal forceps biopsy is a safe, effective, minimally invasive procedure for histological characterization in patients presenting with obstructive jaundice due to a non-primary biliary tumor.

Keywords: Liver; Biliary tract diseases; Radiology, interventional/methods; Biopsy/methods; Fluoroscopy/methods.