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.

Clinical Image Quality and Sensitivity in an Organized Mammography Screening Program.

PURPOSE: The study sought to examine the association between clinical image quality of mammograms and screening sensitivity. METHODS: Four radiologists evaluated the clinical image quality of 374 invasive screen-detected cancers and 356 invasive interval breast cancers for which quality evaluation of screening mammograms could be assessed from cancers diagnosed among participants in the Quebec Breast Cancer Screening Program in 2007. Quality evaluation was based on the Canadian Association of Radiologists accreditation criteria, which are similar to those of the American College of Radiology. The association between clinical quality and screening sensitivity was assessed by logistic regression. Adjusted sensitivity and adjusted sensitivity ratios were obtained through marginal standardization. No institutional review board approval was required. RESULTS: A proportion of 28% (206 of 730) of screening mammograms had lower overall quality for the majority of assessments. Positioning was the quality attribute that was the most frequently deficient. The 2-year screening sensitivity reached 68%. Sensitivity of screening was not statistically associated with the overall quality (ratio of 2-year sensitivity = 1.03; 95% confidence interval: 0.93-1.15) or with any quality attributes (positioning, exposure, compression, sharpness, artifacts, contrast). Results were similar for the 1-year sensitivity. CONCLUSIONS: Although not all mammograms in the Quebec screening program met the optimum quality required by the Canadian Association of Radiologists or American College of Radiology accreditation, the screening mammograms produced in this population-based organized screening program reached a high enough level of quality so that the remaining variation in quality is too little to impair screening sensitivity.

Porcine model of intracoronary pulverization of stent struts by rotablation atherectomy.

OBJECTIVE: To evaluate the feasibility and safety of rotablation atherectomy in a suboptimally expanded stent. METHODS: Seven pigs underwent suboptimal stent expansion in the left anterior descending coronary. Pulverization of the stent struts was performed by rotablation atherectomy with two different burr sizes. Two types of control porcine models were used: pigs with fully expanded stents and pigs without stents. Continuous electrocardiogram readings as well as microscopic and radiologic analysis of cardiac tissue were performed. RESULTS: Rotablation atherectomy reduces the suboptimally expanded stent by (26.95 ± 5.03)%. Ninety-five percent of the metal microparticles, imbedded in the suboptimally expanded stent group cardiac tissue, are less than 15 µm. Transient vasospasm and ST segments elevations were observed during rotablation atherectomy, which returned to basal conditions at the end of the intervention. CONCLUSION: Our study demonstrated the feasibility and safety of using rotablation atherectomy to pulverize stent struts in a suboptimally expanded stent.

[Nephrogenic systemic fibrosis: more hard times for renal failure patients]. / La fibrose systémique néphrogénique: nouveau coup dur pour les insuffisants rénaux.

To date, more than 200 cases of nephrogenic systemic fibrosis have been documented worldwide. All patients have had renal failure, most of them requiring dialysis. We herein describe the course of a hemodialyzed patient who developed nephrogenic systemic fibrosis in the months following magnetic resonance angiography of the lower extremities. The disease is characterized by skin thickening and tendon fibrosis leading to joint contractures that can quickly confine the patient to a wheelchair. Systemic involvement may occur, leading to cardiomyopathy, pulmonary fibrosis, pulmonary hypertension or even death. No consistently effective therapy has been reported. An association between gadolinium exposure and the development of the disease has been found, although no causal link has yet been proven. In a patient with renal failure, magnetic resonance imaging with gadolinium enhancement should be done only after having seriously considered the risk/benefit ratio. Implications concerning the choice of imaging methods when searching for ischemic nephropathy or aorto-iliac disease before renal transplantation are discussed.