Description: Purpose To evaluate the feasibility of modified fusion imaging (MFI) combining CT gastrography (CTG) and CT angiography (CTA) in the preoperative mapping and intraoperative localization of small (〈3 cm) submucosal lesions (SMLs) during laparoscopic exogastric wedge resection. Methods Thirty consecutive patients scheduled for laparoscopic wedge resection of small SMLs (〈3 cm) were enrolled. MFI was reconstructed using a volume rendering of the arterial phase CT data acquired after gastric distension. With MFI, the possibility of preoperative mapping and feasibility for successful intraoperative localization was evaluated using intraoperative findings as the reference standard. Results In 21 of 30 patients (70%), preoperative mapping was possible. Preoperative mapping was feasible for successful intraoperative localization in 13 of 14 patients (93%) who underwent exogastric resection. Conclusions MFI combining CTG and CTA is a feasible method for developing preoperative and intraoperative “road maps” for performing laparoscopic exogastric wedge resection of small SMLs.

Description: Purpose To describe the natural history of liver adenomatosis (LA), including complications and changes in lesion size over time. Materials and methods Eighteen patients with clinical diagnosis of LA were included. Clinical and biochemical information were collected. The initial and follow-up MR studies were reviewed retrospectively to determine change in lesion size and imaging features. Results Seventeen patients were women (94.4%). The mean age of the initial MR study was 37.0 years (18–52 years). The median size of the largest lesion was 6.7 cm (range 3.0–13.5 cm). Intratumoral bleeding was detected on MRI in 9 lesions, in 7 patients (38.8%). The median size for hemorrhagic lesions was 7.6 cm (range 4.1–13.5 cm). During the mean follow-up period of 29.4 (range 4–98) months, 10 patients had stable disease (55.6%), and 8 patients had tumor regression (44.4%). Of 8 patients who were followed without intervention, 3 patients (37.5%) had spontaneous regression. No malignant transformation or lesion progression was occurred. Conclusion During an over 2-year follow-up period, the majority of lesions of LA appeared to remain stable or showed tumor regression. Spontaneous tumor regression can be observed in approximately 37% of individuals in the age range of 28–53 years.

Description: Myelolipoma is an uncommon benign tumor that classically arises in the adrenal glands. Most cases are asymptomatic, with incidental detection of this tumor on cross-sectional imaging performed for other causes. Extra-adrenal occurrence of myelolipoma has been infrequently reported, with scarce radiology literature on the topic. We present radiologic and pathologic correlation in two cases of image-guided biopsy proven extra-adrenal myelolipoma in the presacral and paraaortic location, with review of literature.

Description: Purpose To assess the role of transabdominal ultrasound after oral administration of an echoic cellulose-based gastric contrast agent (TUS-OCCA) for detection and characterization of small gastric subepithelial masses (≤3 cm) by comparison with endosonography (EUS). Methods Ninety-five patients with small gastric subepithelial masses detected by gastroscopy examination were enrolled. For each patient, TUS-OCCA was performed prior to EUS by a skilled examiner. TUS-OCCA diagnoses were compared with those of EUS. Results TUS-OCCA had a detection rate of 94% (89 of 95) in visualizing small gastric subepithelial masses previously detected by gastroscopy. The sizes of 6 undetected masses ranged from 7 to 12 mm (4 located at the fundus, 2 at the cardia). All of six patients whose lesions were undetected by TUS-OCCA were obese. The findings of gastric subepithelial masses demonstrated by TUS-OCCA were similar to that shown on EUS. Conclusions TUS-OCCA can provide useful information about small gastric subepithelial masses, especially for the patients who are not obese. It can be used to follow gastric submucosal tumors that are not excised.

Description: Purpose MR elastography (MRE) can serve as an accurate surrogate marker of liver fibrosis. For any diagnostic test that is to replace the current reference standard, interobserver agreement should be at least as good and preferably better. The objective of this study was to perform a head-to-head comparison of the interobserver agreements of MRE and liver fibrosis staging on biopsy in a single cohort of hepatitis patients. Methods One hundred and three patients with viral hepatitis B or C who had a liver biopsy underwent MRE. Two readers independently selected a region-of-interest (ROI) in the liver to derive elasticity values. Two pathologists first independently staged fibrosis on biopsies using the METAVIR classification and subsequently held a consensus meeting. Interobserver agreements of elasticity values and fibrosis stages were assessed with intraclass correlation coefficients (ICC). Results MRE and biopsy data were available for 85/103 patients. ICC of pathologists staging fibrosis was almost perfect at 0.91 (95% CI 0.86–0.94). ICC for MRE readers was significantly ( P  〈 0.0001) higher at 0.99 (95% CI 0.98–1.00). Conclusions Interobserver agreement for liver fibrosis staging was almost perfect for both histopathology and MRE, with a significant higher agreement for MRE. Its high interobserver agreement and reliable accuracy support the use of MRE as a non-invasive screening tool for liver fibrosis.

Description: Purpose Endoscopy is recommended to screen for esophageal varices in patients with cirrhosis. The objective of this study was to identify features on abdominal CT imaging associated variceal hemorrhage (VH). Methods A case–control study was performed among patients with cirrhosis who had a CT scan. Consecutive patients who experienced VH were included as cases, and patients without VH served as controls. Two radiologists recorded the maximal esophageal varix diameter in addition to other measures of portal hypertension at CT. Results The most powerful CT parameter associated with VH was the esophageal varix diameter (5.8 vs. 2.7 mm, p  〈 0.001; adjusted OR 1.84 per mm, p  = 0.009). 63% of individuals with VH had a maximal varix diameter ≥5 mm compared to 7.5% of cirrhotic patients without VH ( p  〈 0.001). In contrast, the proportion of individuals whose largest varix was 〈3 mm was 7.4% among VH cases compared to 54.7% among controls ( p  = 0.001). The varix diameter powerfully discriminated those with and without VH (C-statistic 0.84). Conclusions A large esophageal varix diameter is strongly associated with subsequent VH. A threshold of 〈3 and ≥5 mm appears to identify patients with cirrhosis at low and high risk for hemorrhage.

Description: Advanced techniques and equipment in laparoscopic surgery offer advantages over open surgery, expanding the application of this minimally invasive procedure to a wide range of abdominal operations that used to be performed as an open procedure. Laparoscopic surgery is performed in the closed abdominal cavity in which the space is limited. To create a working space in the abdominal cavity, an artificial pneumoperitoneum is established and multiple ports are placed for the introduction of various laparoscopic instruments. Unlike open surgery in which the incision is made just above the target organ, laparoscopic access is made away from the area of dissection, with the instruments triangulated around the target organ within the abdomen. This fundamental difference in approach between the open and laparoscopic procedures may lead to peculiar postoperative complications after laparoscopic surgery, which may be present away from the target organ or in the abdominal wall, and be easily missed on postoperative imaging studies. These complications include port-related direct organ injuries, such as abdominal organ or vascular injury; abdominal wall complications related to laparoscopic port insertion such as vascular injury, infection, and hernia; abdominal wall complications related to specimen removal, such as port site tumor seeding and endometriosis; and complications related to gas insufflation. The radiologist plays an important role in the diagnosis of complications after laparoscopic surgery, and therefore should be familiar with the features of such complications on imaging scans in the era of laparoscopic surgeries.

Description: Objective The purpose of the present study was to evaluate the usefulness of coronal reformatted images obtained from 64-slice multi-detector computed tomography to assess the ablative margin (AM) in hepatocellular carcinoma (HCC) treated with radio frequency ablation (RFA). Methods Ninety-five HCC nodules were analyzed in 66 HCC patients treated with RFA. Two radiologists and one hepatologist independently reviewed axial CT images with or without coronal reformatted images in HCC treated with RFA. Nodules were determined as AM-sufficient (≥5 mm) or AM-insufficient (〈5 mm). The level of interobserver agreement was measured using the weighted kappa test. The sensitivity, specificity, and positive and negative predictive values (NPVs) of an insufficient AM (〈5 mm) to predict local recurrence were evaluated. Results The numbers of AM-sufficient nodules judged by readers 1–3 based on axial images and both axial and coronal images were 56, 49, and 58, and 47, 33, and 48, respectively. Excellent agreement and good to excellent agreement were obtained among the three readers on axial image readings and both axial and coronal image readings, respectively. The mean sensitivity, specificity, and positive and NPVs of an insufficient AM on axial images and both axial and coronal images to predict local recurrence were 64%, 60%, 17%, and 93%, and 95%, 50%, 20%, and 97%, respectively. Conclusions Coronal reformatted CT images should be utilized to evaluate the AM in HCC treated with RFA in order to decrease the risk of local recurrence following treatment.

Description: The International Society of Urological Pathology recently proposed classifying thyroid-like follicular renal cell carcinoma (TLF-RCC) as an emerging entity in renal epithelial tumors. Their entire proposal will be the framework for the next World Health Organization classification of renal tumors. Fewer than 15 cases of TLF-RCC have been reported in the literature up to date. We describe the multimodality imaging features of a patient with TLF-RCC. To our knowledge, this is the first case report in the literature commenting on the multimodality imaging appearance of this tumor.

Description: The purpose of this study is to describe our experience with cases of false negative findings at conventional colonoscopy (CC) that were identified by CT colonography (CTC). Conventional colonoscopy (CC) is the universally accepted gold-standard technique for the diagnosis of colonic polyps and cancers, however occasionally this method can generate false negative findings. We present examples of false negatives at CC, correctly identified by CT colonography (CTC), and later confirmed at a second endoscopy, describing the reasons of false negative, when possible.