Use of Imaging to Predict Complete Response of Colorectal Liver Metastases after Chemotherapy: MR Imaging versus CT Imaging.

Purpose To compare the diagnostic performances of contrast agent-enhanced computed tomography (CT) and gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced liver magnetic resonance (MR) imaging (referred to as EOB MR imaging) in the evaluation of disappearing colorectal liver metastases (CRLMs) after chemotherapy. Materials and Methods The eight institutional review boards approved this retrospective study and waived the requirement for informed consent. On the basis of retrospective searches in eight hospitals, 87 patients with 393 CRLMs, each patient with one or more CRLM that later disappeared on contrast-enhanced CT scans after chemotherapy, and subsequently underwent surgery for the CRLMs, were enrolled. The anonymized imaging data and case report forms were sent to the central review system and independently reviewed by four radiologists. All anonymized data were randomly allocated into two groups (groups A and B), which were read by two independent readers. True absence of tumor was defined as pathologic absence of tumor for resected lesions and no in situ recurrence within 1 year after surgery for lesions left unresected at each 3-month follow-up contrast-enhanced CT. Positive predictive values for absence of tumor and for residual tumor on contrast-enhanced CT and EOB MR images were compared by using a generalized estimating equation. Results Among 393 CRLMs, the positive predictive value for absence of tumor on EOB MR images (78.0%; 95% confidence interval [CI]: 63.68%, 87.74%) was significantly higher than that on contrast-enhanced CT scans (35.2%; 95% CI: 25.11%, 46.79%; P < .001). The positive predictive value for residual tumor on CT scans (86.0%; 95% CI: 78.61%, 91.16%) was higher than that on EOB MR images (83.8%; 95% CI: 77.50%, 88.67%) without statistical significance (P = .330). Conclusion EOB MR imaging was superior to contrast-enhanced CT imaging for assessment of disappearing CRLMs after chemotherapy. © RSNA, 2017 Online supplemental material is available for this article.

Neuroendocrine neoplasms of the extrahepatic bile duct: radiologic and clinical characteristics.

PURPOSE: To retrospectively identify the radiological and clinical features of neuroendocrine neoplasms of the extrahepatic bile duct. MATERIALS AND METHODS: Institutional review board approval was obtained. Between August 2003 and August 2013, 11 patients (range 41-79 years) who had undergone surgery in our institution for neuroendocrine neoplasms of the extrahepatic bile duct were identified. Clinical features (symptoms, laboratory finding, and medical history) were reviewed. A pathologist reviewed the pathology of 11 patients. CT (n = 11), MRI (n = 10), and PET/CT (n = 8) were reviewed by two radiologists in consensus. They were blinded to the clinical features and pathology report. The tumor location was assessed on CT and was classified as occurring in the common hepatic duct, cystic duct, and common bile duct. The tumor shape was assessed in ten patients using MRI and in one patient using CT. The shape was classified as nodular, intraductal-growing, and periductal-infiltrating type. The FDG activity on PET/CT was also evaluated. Correlation of image findings with pathology was made by a radiologist who didn't participate in the image analysis. RESULTS: There were five men and six women and their median age was 65 years. On pathology examination, seven patients had neuroendocrine carcinoma (64%), three had mixed adenoneuroendocrine carcinoma (27%), and one had neuroendocrine tumor (9%). CT showed that the tumors were located in the common bile duct in seven patients (64%), the common hepatic duct in two (18%), and the cystic duct in two patients (18%). Five tumors were classified as nodular (45%), five as intraductal-growing (45%), and one as periductal-infiltrating type (9%). PET/CT showed increased FDG activity, ranging from 2.7-15.9, in eight patients with neuroendocrine carcinoma. CONCLUSION: The most common location of neuroendocrine neoplasms of the extrahepatic bile duct is the common bile duct. Most of them are nodular or intraductal-growing type.

Quality of reporting noninferiority/similarity in research studies of diagnostic imaging.

PURPOSE: To evaluate the quality of reporting noninferiority/similarity in research studies of diagnostic imaging. MATERIALS AND METHODS: All 661 original research articles published in Radiology and European Radiology in 2012 were hand searched to find original studies of diagnostic imaging that included a claim of noninferiority/similarity as a study conclusion. A separate MEDLINE search was performed to identify original studies of diagnostic imaging designed as noninferiority studies, defined as studies at least embodying noninferiority margin, published in English between April 2007 and December 2012. Thirty-eight articles in the first category and 30 in the second category reporting a total of 31 noninferiority studies were finally collected after screening for eligibility. The quality of the reported analytic methodology was evaluated largely according to the extended Consolidated Standards of Reporting Trials, or CONSORT, statement to cover noninferiority studies. In the 31 designated noninferiority studies, the authors evaluated the following key areas of compliance required for proper reporting: noninferiority margin defined and justification provided, sample size calculated according to noninferiority methodology, and use of proper statistical analysis. RESULTS: Of the 38 studies concluding noninferiority/similarity, one study (3%) used proper analytic method. Twenty-nine of the 38 studies (76%), 28 of which also omitted sample size estimation, claimed noninferiority/similarity for P ≥ .05 from conventional two-sided superiority testing. Of the 31 designated noninferiority studies, seven (23%) fulfilled the requirements for proper reporting. Justification for noninferiority margin was provided in 15 of the 31 studies (48%). Proper sample size estimation was done in 14 of the 31 studies (45%). CONCLUSION: The quality of reporting noninferiority/similarity in recently published research studies of diagnostic imaging was deficient.

Primary solid pancreatic tumors: recent imaging findings updates with pathology correlation.

The imaging findings of primary solid pancreatic tumors have long been studied and are generally well-established. However, interestingly enough, a wealth of new information has recently appeared in the literature, including the imaging findings of novel or previously seldom-addressed pathological entities as well as atypical imaging findings of common tumors, both of which are well-correlated with the pathology findings. 5 %-14 % of pancreatic ductal adenocarcinomas have been reported on dynamic contrast-enhanced computed tomography to be isoattenuating, and thus making the imaging diagnosis challenging. The imaging-pathology correlation in such isoattenuating tumors is presented along with a discussion regarding the early imaging detection of pancreatic cancers. Colloid (or mucinous non-cystic) pancreatic cancer may resemble a less harmful cystic lesion due to its abundant extracellular mucin, and thus requiring caution in the image interpretation. Serotonin-producing neuroendocrine tumors have recently been recognized as a separate entity from usual neuroendocrine tumors. Exuberant fibrosis caused by serotonin metabolites and scarce tumor cells creates a unique pattern of pancreatic ductal obstruction seen on imaging. Small solid pseudopapillary tumors appear as unencapsulated, completely solid lesions with gradually increasing enhancement after contrast administration, unlike typical solid pseudopapillary neoplasms that present as a large mixed solid and degenerated cystic or hemorrhagic mass encapsulated by a thick capsule and which, therefore, tend to be misdiagnosed on imaging. Solid serous adenoma is a rare, solid variant of serous cystadenoma and appears on imaging as a hypervascular, solid nodule due to its genuinely microscopic cystic, alveolar, and ectatic tubular tumor architecture.

Ischemic Colitis Associated with Rhabdomyolysis and Heat Stroke after an Intense Exercise in Young Adult.

Ischemic colitis primarily affects the elderly with underlying disease, but it rarely occurs in young adults with risk factors, such as coagulopathy or vascular disorder. Moreover, it is extremely rare in the very young without risk factors. This paper presents a patient with ischemic colitis associated with heat stroke and rhabdomyolysis after intense exercise under high-temperature conditions. A 20-year-old man presented with mental deterioration after a vigorous soccer game for more than 30 minutes in sweltering weather. He also presented with hematochezia with abdominal pain. The laboratory tests revealed the following: AST 515 U/L, ALT 269 U/L, creatine kinase 23,181 U/L, BUN 29.1 mg/dL, creatinine 1.55 mg/dL, and red blood cell >50/high-power field in urine analysis. Sigmoidoscopy showed ischemic changes at the rectum and rectosigmoid junction. A diagnosis of ischemic colitis and rhabdomyolysis was made, and the patient recovered after conservative and fluid therapy. This case showed that a diagnosis of ischemic colitis should be considered in patients who present with abdominal pain and bloody diarrhea after intense exercise, and appropriate treatment should be initiated immediately.

CT colonography in the diagnosis and management of colorectal cancer: emphasis on pre- and post-surgical evaluation.

This article addresses the use of computed tomographic colonography (CTC) for the diagnosis and management of colorectal cancer, focusing on presurgical evaluation of the colon proximal to an occlusive cancer and surveillance after cancer resection surgery. The key evidences accumulated in the literature and future work needed are summarized. CTC is a technically robust and the most practical method to evaluate the colon proximal to an occlusive cancer, which prevents colonoscopic examination past the occlusion, either before or after metallic stent placement. The high sensitivity of CTC for detecting cancers and advanced adenomas in the proximal colon can help prevent additional surgical procedures in patients showing negative results. However, the accuracy of CTC for distinguishing intramural cancers from adenomas is low, and the technique is limited in guiding management when a medium-sized lesion that do not show invasive features such as pericolic extension or nodal metastasis is found in the proximal colon. A maximal diameter ≥ 15 mm has been proposed as a criterion for surgical removal of proximal lesions. However, this needs to be verified in a larger cohort. In addition, the influence of presurgical CTC results on the current post-cancer resection colonic surveillance timeline remains to be determined. CTC can be readily added to the routine abdominopelvic CT in the form of contrast-enhanced CTC, which can serve as an effective stand-alone tool for post-cancer resection surveillance of both the colorectum and extracolonic organs. Although the accuracy of CTC has been demonstrated, its role in the current colonoscopy-based postoperative colonic surveillance protocols remains to be determined. Readers of CTC also need to be knowledgeable on the colonic lesions that are unique to the postoperative colon.