Canadian Association of Radiologists Practice Guidelines for Computed Tomography Colonography.

Colon cancer is the third most common malignancy in Canada. Computed tomography colonography (CTC) provides a creditable and validated option for colon screening and assessment of known pathology in patients for whom conventional colonoscopy is contraindicated or where patients self-select to use imaging as their primary modality for initial colonic assessment. This updated guideline aims to provide a toolkit for both experienced imagers (and technologists) and for those considering launching this examination in their practice. There is guidance for reporting, optimal exam preparation, tips for problem solving to attain high quality examinations in challenging scenarios as well as suggestions for ongoing maintenance of competence. We also provide insight into the role of artificial intelligence and the utility of CTC in tumour staging of colorectal cancer. The appendices provide more detailed guidance into bowel preparation and reporting templates as well as useful information on polyp stratification and management strategies. Reading this guideline should equip the reader with the knowledge base to perform colonography but also provide an unbiased overview of its role in colon screening compared with other screening options.

MRI of the penis.

This article reviews the anatomy and magnetic resonance imaging (MRI) appearance of the penis. The recommended technique for MRI of the penis is outlined, with discussion of the benefits and drawbacks to imaging the penis after artificial erection. Common penile pathologies are reviewed, with a summary of their clinical features, MRI appearance, and treatment. The ability to demonstrate the erectile bodies and vasculature helps to evaluate vascular pathologies such as priapism, Mondor disease, and cavernosal thrombosis. MRI is also a useful tool to assess for traumatic abnormalities of the penis, with the depiction of soft tissue anatomy and fascial layers allowing for evaluation of penile fracture and penile contusion. Malignant disease of the penis is also reviewed, including squamous cell carcinoma, urethral carcinoma, metastases, and rare neoplasms. Staging of these neoplasms is addressed, with discussion of how MRI can be used to assess the extent of tumor involvement. MRI also clearly demonstrates the tunica albuginea, which allows for evaluation of Peyronie's disease.

Pancreatic cancer screening.

PURPOSE: This article reviews the current evidence surrounding pancreatic cancer screening. The current targets of screening include identification of early pancreatic cancer, as well as the two most important precursor lesions; intraductal papillary mucinous neoplasm and high grade pancreatic intraepithelial neoplasia. Given the relatively low incidence of pancreatic adenocarcinoma in the general population, patients with elevated risk based on family history or an underlying genetic syndrome are felt to be the most appropriate patients to undergo screening. METHODS: An extensive review of the literature was performed and the major findings of the available literature regarding pancreatic screening are reviewed in detail. RESULTS: Several prospective trials have evaluated pancreatic cancer screening in high-risk groups. The results of those trials are summarized in this article. Current consensus guidelines and recommendations from the International Cancer of the Pancreas Screening Consortium Summit are also discussed. CONCLUSIONS: The exact benefit of pancreatic cancer screening remains unclear at this time, but emerging evidence suggests that there is a window of opportunity to detect precursor lesions and early pancreatic adenocarcinomas in high-risk patient populations. Better understanding of the pathway of carcinogenesis will hopefully improve our ability to detect early, resectable pancreatic carcinomas, and provide a mortality benefit to patients at significantly elevated risk of pancreatic adenocarcinoma.

Utility of balanced steady-state free precession MR venography in the diagnosis of lower extremity deep venous thrombosis.

OBJECTIVE: The purpose of this study was to determine the sensitivity and specificity of balanced steady-state free precession MR venography in the diagnosis of lower extremity deep venous thrombosis. SUBJECTS AND METHODS: After undergoing lower extremity ultrasound because of suspicion of deep venous thrombosis, 64 patients were prospectively recruited to undergo balanced steady-state free precession MR venography with ultrasound as the reference standard. Ultrasound images were independently interpreted by two blinded ultrasound radiologists, and MR venograms were independently interpreted by two blinded MRI radiologists. The sensitivity, specificity, positive predictive value, and negative predictive value of MR venography were calculated for the diagnoses of all deep venous thrombosis, acute thrombi, and thrombosis of the popliteal, femoral, and common femoral veins individually. Proximal extent, thrombus age, ancillary findings, and interobserver agreement calculated with the Cohen kappa test were evaluated for ultrasound and MRI. The McNemar test was used to evaluate for statistical differences in diagnostic accuracy. RESULTS: MR venography had a sensitivity of 94.7%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 97.7% for the diagnosis of all thrombi. For acute thrombi, the MR venography and ultrasound results were completely concordant. MR venography depicted greater proximal extent in five of 18 cases in which thrombosis was found. The MR venographic findings agreed completely with the ultrasound findings in determination of thrombus age. For both ultrasound and MR venography, interobserver agreement was 100% on a per-patient basis. No statistical difference was identified in the diagnostic performance of the two techniques. CONCLUSION: Balanced steady-state free precession MR venography is highly accurate in the diagnosis of lower extremity deep venous thrombosis.