Anoperineal disease in Hidradenitis Suppurativa : MR imaging distinction from perianal Crohn's disease.

OBJECTIVE: To determine whether Hidradenitis suppurativa (HS)-related anoperineal disease can be distinguished from Crohn's disease (CD) using MRI. METHODS: Pelvic MRI of 23 HS and 46 CD patients with anoperineal disease between 2007 and 2014 were independently analysed by two radiologists. For diagnosis of HS, sensitivity, specificity and positive likelihood ratios (LRs) of inflammatory features and of their anatomical distribution were calculated and compared to those of CD. RESULTS: In HS, fistulae were less present (P = .033) and less frequently involved the sphincters (P = .001) than in CD. Granulomas were more frequent (P = .0005). For anterior/inguinal and posterior localizations, sensitivity, specificity and LR for diagnosis of HS were 70% (49.1, 84.4), 87% (74.3, 93.9), 5.3 (2.41, 11.79) and 57% (36.8, 74.4), 93% (82.5, 97.8), 8.67 (2.74, 27.41), respectively. Combination of signs including posterior involvement, absence of rectal wall thickening and bilaterality of features yielded specificity of 100% (95% CI: 92.3-100) for HS. CONCLUSION: Although MRI presentations of anoperineal disease may overlap between CD and HS, specific diagnosis of HS is possible with a combination of three features: absence of features' predominance in perianal area, absence of rectal wall thickening and bilaterality of features. KEY POINTS: • Spectrum of MRI features of HS-related anoperineal disease is wide. • Specific diagnosis of HS-related anoperineal disease is possible using MR imaging. • A combination of three MR signs allows distinction between HS and CD.

Diffusion-weighted imaging for the detection of mesenteric small bowel tumours with Magnetic Resonance--enterography.

PURPOSE: To retrospectively investigate the added value of diffusion-weighted MR imaging (DWI) for detecting mesenteric small bowel tumours (MSBTs) via MR-enterography. MATERIALS AND METHODS: MR-enterographies of 98 patients with suspected MSBTs were blindly analyzed by two independent readers for the presence of MSBTs. Four imaging sets including "standard" (Haste and TrueFisp), "standard + DWI," "standard + gadolinium-enhanced" and "standard + DWI + gadolinium-enhanced" were reviewed. Diagnostic performance of different readings were compared with McNemar's test. RESULTS: Twenty-nine MSBTs were pathologically confirmed. For R1 (junior radiologist) sensitivity, specificity, PPV, NPV and accuracy for the detection of MSBTs via standard MRI were 52 % [95 % CI: 34 %-70 %] (15/29), 94 % [95 % CI: 89 %-100 %] (65/69), 79 % [95 % CI: 61 %-97 %] (15/19), 82 % [95 % CI: 74 %-91 %] (65/79) and 82 % [95 % CI: 74 %-89 %] (80/98), respectively. For R2 (senior radiologist) they were 76 % [95 % CI: 60 %-91 %] (22/29), 96 % [95 % CI: 91-100 %] (66/69), 88 % [95 % CI: 75 %-100 %] (22/25), 90 % [95 % CI: 84 %-97 %] (66/73) and 90 % [95 % CI: 84 %-96 %] (88/98), respectively. Adding DWI they were 72 % [95 % CI: 56 %-89 %] (21/29), 91 % [95 % CI: 85 %-98 %] (63/69), 78 % [95 % CI: 62 %-94 %] (21/27), 89 % [95 % CI: 81 %-96 %] (63/71) and 87 % [95 % CI: 80 %-94 %] (85/98) for R1 and 79 % [95 % CI: 65 %-94 %] (23/29), 97 % [95 % CI: 93 %-100 %] (67/69), 92 % [95 % CI: 81 %-100 %] (23/25), 92 % [95 % CI: 86 %-98 %] (67/73) and 92 % [95 % CI: 86 %-97 %] (90/98) for R2. Sensitivities for tumour detection were higher after adding DWI to standard MRI, although only for R1 was this significant (P = 0.03). Adding DWI to standard + gadolinium-enhanced MRI did not significantly increase MR performance. CONCLUSION: DWI improves MSBT detection via MR-enterography compared to standard unenhanced MR-enterography, especially for unexperienced readers. KEY POINTS: • MR-enterography is accurate for the detection of mesenteric small-bowel tumours. • Diffusion-weighted sequencing helps inexperienced readers detect small-bowel tumours with MR-enterography. • Diffusion-weighted sequencing adds value to standard MR-enterography when gadolinium is contraindicated.

MRI and CT of sacrocolpopexy.

OBJECTIVE: The purpose of this article is to describe the surgical procedure of sacrocolpopexy as well as the normal postoperative features and complications on cross-sectional imaging, with an emphasis on MRI. CONCLUSION: Sacrocolpopexy with mesh insertion is a commonly performed operation to treat pelvic organ prolapse. MDCT and MRI are used not only to evaluate for potential complications of the procedure but also to evaluate for functional disorders and recurrent prolapse.