Endoscopy remains the reference standard for the diagnosis and assessment of patients with inflammatory bowel disease (IBD), but it has several important limitations. Cross-sectional imaging techniques such as magnetic resonance enterography (MRE) and intestinal ultrasound (IUS) are better tolerated and safer. Moreover, they can examine the entire bowel, even in patients with stenoses and/or severe inflammation. A variety of cross-sectional imaging activity scores strongly correlate with endoscopic measures of mucosal inflammation in the colon and terminal ileum. Unlike endoscopy, cross-sectional techniques allow complete visualisation of the small-bowel and assess for extraintestinal disease, which occurs in nearly half of patients with IBD. Extramural findings may predict outcomes better than endoscopic mucosal assessment, so cross-sectional techniques might help identify more relevant therapeutic targets. Coupled with their high sensitivity, these advantages have made MRE and IUS the primary non-invasive options for diagnosing and monitoring Crohn’s disease; they are appropriate first-line investigations, and have become viable alternatives to colonoscopy. This review discusses cross-sectional imaging in IBD in current clinical practice as well as research lines that will define the future role of these techniques.

Magnetic resonance enterography [MRE] and intestinal ultrasound [IUS] have developed rapidly in the past few decades, emerging as the primary non-invasive options for both diagnosing and monitoring Crohn’s disease [CD]. In this review, we evaluate the pertinent data relating to the use of MRE and IUS in CD. We summarise the key imaging features of CD activity, highlight their increasing role in both the clinical and the research settings, and discuss how these modalities fit within the diagnostic pathway. We discuss how they can be used to assess disease activity and treatment responsiveness, including the emergence of activity scores for standardised reporting. Additionally, we address areas of controversy such as the use of contrast agents, the role of diffusion-weighted imaging, and point-of-care ultrasound. We also highlight exciting new developments, including the applications of artificial intelligence. Finally, we provide suggestions for future research priorities.

Renal and urinary tract complications related to inflammatory bowel disease (IBD) have been relatively understudied in the literature compared with other extraintestinal manifestations. Presentation of these renal manifestations can be subtle, and their detection is complicated by a lack of clarity regarding the optimal screening and routine monitoring of renal function in IBD patients. Urolithiasis is the most common manifestation. Penetrating Crohn’s disease involving the genitourinary system as an extraintestinal complication is rare but associated with considerable morbidity. Some biologic agents used to treat IBD have been implicated in progressive renal impairment, although differentiating between drug-related side effects and deteriorating kidney function due to extraintestinal manifestations can be challenging. The most common findings on renal biopsy of IBD patients with renal injury are tubulointerstitial nephritis and IgA nephropathy, the former also being associated with drug-induced nephrotoxicity related to IBD medication. Amyloidosis, albeit rare, must be diagnosed early to reduce the chance of progression to renal failure. In this review, we evaluate the key literature relating to renal and urological involvement in IBD and emphasize the high index of suspicion required for the prompt diagnosis and treatment of these manifestations and complications, considering the potential severity and implications of acute or chronic loss of renal function. We also provide suggestions for future research priorities.

Renal cryoablation is a treatment option for early stage renal cell carcinomas with excellent oncological outcomes and low morbidity. This review outlines the technique of renal cryoablation and provides a guide for interventional radiologists on setting up an integrated service within a renal cancer network multidisciplinary setting. Patient selection and preparation, together with the technical aspects which ensure optimal oncological outcomes and avoid collateral damage to adjacent organs are highlighted.

Purpose To compare long-term graft and patient survival after percutaneous angioplasty (PTA) or stent placement for transplant renal artery stenosis (TRAS) with a control cohort without TRAS. Materials and Methods This is a retrospective matched cohort study of 41 patients (median age, 49 years; range, 18-72 years), including 27 male patients (median age, 48 years; range, 18-67 years) and 14 female patients (median age, 52 years; range, 24-68 years), with TRAS from December 1995 through 2016. Primary end points were death-censored graft and patient survival, compared by using log-rank test and Cox proportional regression. Secondary outcomes were improvement in renal function, blood pressure (BP), and complications. Results Twenty-four patients underwent PTA and 17 received stent placements. Ten-year graft survival was 92.1% (range, 83.2%-100%) versus 81.4% (range, 67.8%-95.3%) (P = .56), and 10-year patient survival was 89.9% (79.1%-100%) versus 84.7% (72.1%-97.5%) (P = .49), for the study and control groups, respectively. Five patients (12%) resumed dialysis in each group and a total of 17 patients died (eight in the study group and nine in the control group). Most patients died with a functioning graft (seven of eight in the study group and seven of nine in the control group). Posttreatment median systolic and diastolic BP improved by 12% and 7.4%, respectively, and serum creatinine improved by 27%. Normal systolic BP and serum creatinine level at 1 year after treatment were associated with better survival for patients (P = .04; hazard ratio [HR], 1.04; 95% confidence interval [CI]: 1.0, 1.075) and grafts (P < .001; HR, 1.02; 95% CI: 1.0, 1.027). Other covariates, including PTA versus renal stent placement, intra-arterial pressure gradient greater than 10%, diastolic BP, age at transplantation, sex, graft type, rejection, and delayed graft function, were not significant. Five patients (12.2%) had a complication (Society of Interventional Radiology class A, two of 41 [4.9%]; class B, two of 41 [4.9%]; and class D, one of 41 [2.4%]); 30-day graft loss and patient mortality were zero. Conclusion Long-term graft and patient survival after endovascular correction of transplant renal artery stenosis (TRAS) was similar to that without TRAS and most patients avoided returning to dialysis. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by Dickey and Durrani in this issue.

Cross-sectional imaging, particularly MR enterography and intestinal US, is now the mainstay for diagnosing and monitoring inflammatory bowel disease, providing a robust means of assessing activity and therapeutic response.