ESGAR consensus statement on the imaging of fistula-in-ano and other causes of anal sepsis.

OBJECTIVES: To develop imaging guidelines for patients with fistula-in-ano and other causes of anal sepsis. METHODS: An expert group of 13 members of the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) used a modified Delphi process to vote on a series of consensus statements relating to the imaging of patients with potential anal sepsis. Participants first completed a questionnaire to gather practice information and to help frame the statements posed. RESULTS: In the first round of voting, the expert group scored 51 statements of which 45 (88%) achieved immediate consensus. The remaining 6 statements were redrafted following input from the expert group and consensus achieved for all during a second round of voting, including an additional statement drafted. No statement was rejected due to a lack of consensus. After redrafting to improve clarity, 53 individual statements were presented. CONCLUSION: These expert consensus statements can be used to guide appropriate indication, acquisition, interpretation and reporting of medical imaging for patients with potential fistula-in-ano and other causes of anal sepsis. KEY POINTS: • Medical imaging, notably magnetic resonance imaging, is used widely for the diagnosis and monitoring of fistula-in-ano and other causes of anal and perianal sepsis. • While the indexed medical literature is clear that diagnostic accuracy is potentially excellent, this depends on competent image acquisition and interpretation. • In order to facilitate this, the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) has produced expert consensus guidelines regarding the imaging of fistula-in-ano and related conditions.

Utility of routine use of breast ultrasound following contrast-enhanced spectral mammography.

AIM: To evaluate whether breast ultrasound (US) is routinely indicated following contrast-enhanced spectral mammography (CESM). MATERIALS AND METHODS: Consecutive screening and diagnostic CESM examinations with concurrent breast US were collected retrospectively (May 2012 to February 2016). Radiologists assigned a separate Breast Imaging-Reporting and Data System (BIRADS) score for CESM and for US. BIRADS scores were grouped into three categories: normal/benign appearing (BIRADS 1, 2); probably benign, short-term follow-up (BIRADS 3); or suspicious appearing (BIRADS 0, 4, 5). Patients with a suspicious-appearing lesion in either US or CESM underwent biopsy. The associations between malignant pathology with either suspicious-appearing CESM or suspicious-appearing US were calculated. The sensitivities and specificities of CESM and US were analysed. RESULTS: Eighty-seven lesions were biopsied, 37 (43%) biopsies were malignant and 50 (57%) were benign. Although suspicious-appearing CESM was associated with malignant biopsies (p<0.0001), suspicious-appearing US was not (p=0.985). Among 37 malignant biopsies, CESM had a sensitivity of 97% (36/37 lesions), compared to 92% (34/37 lesions) with US. None of the malignant biopsies were normal/benign appearing with CESM. One case of follow-up CESM was suspicious-appearing at US and proved to be malignant on biopsy. The specificity of CESM was 40%, which was significantly higher than US at 8%. CONCLUSION: When CESM is suspicious appearing, subsequent US and biopsy is appropriate. With a CESM BIRADS 3, correlation with US is suggested. If the CESM is benign appearing, the routine use of US is questionable, as it may lead to unnecessary benign biopsies.

CT imaging features of symptomatic and asymptomatic floating aortic thrombus.

AIM: To present the computed tomography (CT) imaging features of floating aortic thrombus with emphasis on clinical and radiographic predictors for systemic shower emboli. MATERIALS AND METHODS: A retrospective computerised search for patients with protruding thoracic aortic thrombus on CT was conducted. Clinical and demographic characteristics were retrieved from medical files. Patients were divided into two groups: symptomatic and asymptomatic, based on the presence or absence of documented systemic emboli at the time of diagnosis or during follow-up. CT imaging features were analysed: location and extent of systemic emboli, presence or absence of thrombus insertion calcification, percentage of thrombus circumference that is attached to the aortic wall and thrombus volume. Clinical and demographic variables and CT imaging features were analysed as potentially associated with symptomatic emboli. RESULTS: The symptomatic group included 6/15 (40%) patients and the asymptomatic group included 9/15 (60%) patients. Patients in the symptomatic group were significantly younger (symptomatic: 53.3±11.7 years, asymptomatic: 76.9±8.4 years, p=0.003). All the symptomatic patients were women (100%), while 2/9 (22.2%) of the asymptomatic patients were women, (p=0.007). A non-calcified insertion site was more frequent in the symptomatic group (symptomatic 4/6 [66.7%] versus asymptomatic group 1/9 [11.1%], p=0.011). The percentage of thrombus circumference attached to the aortic wall was significantly smaller in symptomatic patients (symptomatic: 31.8±8.4%, asymptomatic: 43.7±5%, p=0.003). CONCLUSION: The imaging features of symptomatic floating thrombus include a narrow base of attachment and lack of insertion calcification. Free-floating thrombus should be actively sought and diagnosed or excluded when performing CT andiography for emboli.

Diffusion-weighted imaging in quiescent Crohn's disease: correlation with inflammatory biomarkers and video capsule endoscopy.

AIM: To investigate the role of restricted diffusion in quiescent Crohn's disease (CD) patients and its association with inflammatory biomarkers and endoscopic disease. MATERIAL AND METHODS: Fifty-two quiescent CD patients prospectively underwent magnetic resonance enterography (MRE) and video capsule endoscopy (VCE) and were tested for the inflammatory biomarkers, faecal calprotectin (FCP) and C-reactive protein (CRP). Restricted diffusion in the distal ileum was qualitatively (absence/presence) and quantitatively (apparent diffusion coefficient [ADC]) assessed by two readers. The VCE-based Lewis score was calculated for the distal ileum. Restricted diffusion sensitivity and specificity for VCE ulcerations were assessed for patients with elevated (>100 µg/g) or normal (<100 µg/g) FCP. Receiver operating characteristic (ROC) curve was used to assess the ability of ADC to identify patients with concurrent VCE ulceration and elevated FCP. RESULTS: The sensitivity and specificity of restricted diffusion for patients with VCE ulceration were higher in patients with elevated FCP (reader 1: 71.4%, 80%, reader 2: 76.2%, 100%, respectively) compared to patients with normal FCP (reader 1: 46.2%, 61.5%; reader 2: 15.4%, 76.9%, respectively). The ADC had a high diagnostic accuracy for identifying patients that had concurrent VCE ulceration and elevated FCP (reader 1: AUC=0.819, reader 2: AUC=0.832). CONCLUSION: In quiescent CD patients, the presence of restricted diffusion is suggestive of an active inflammation, associated with elevated FCP. Thus, DWI may serve as a clinical tool in the follow-up of these patients, implying subclinical inflammatory flares.

Pitfalls in diagnosing colon cancer on abdominal CT.

AIM: To assess the frequency of undetected colon cancer on conventional abdominal CT and to evaluate the imaging features that are characteristic of those cancers. MATERIALS AND METHODS: The present study included consecutive patients diagnosed with colorectal cancer at colonoscopy (2006-2015) who also underwent abdominal computed tomography (CT) performed for various reasons within a year prior to the colonoscopy. The frequency of undetected lesions was evaluated for the original CT interpretations ("original readers"). Two radiologists ("study readers"), blinded to the tumour location, independently performed interpretations oriented for colon cancer detection. The study readers analysed the imaging features of detected tumours (tumour shape, length, maximal wall thickness, free fluid, fat stranding, vascular engorgement, stenosis, and lymphadenopathy). Imaging features of the cancers undetected by the original readers were evaluated. RESULTS: The study included 127 patients. The original readers' frequency of undetected cancer was 25/127 (19.7%). Each study reader could not identify the cancer in 8/127 (6.3%) patients. Imaging features associated with undetected cancers by the original readers included the absence of fat stranding (p=0.007, p=0.003), absence of vascular engorgement (p<0.0001, p<0.0001) and absence of lymphadenopathy (p=0.005, p=0.004). Undetected tumours were shorter than those detected (original reader: 33.2±11.9 versus 51.4±18.2 mm; study reader: 32.5±9.6 versus 61.3±23.4 mm; p<0.001). CONCLUSION: Colon cancer is undetected in 20% of abdominal CT examinations in patients subsequently proven to have colon cancer at colonoscopy. The absence of fat stranding, vascular engorgement, or lymphadenopathy, and an average tumour length of 3.3 cm are contributing factors for failure of detection. Radiologists' training should emphasis these findings as it may improve cancer detection, and clinicians should be aware of the limitations of abdominal CT.

Differentiation between right tubo-ovarian abscess and appendicitis using CT--a diagnostic challenge.

AIM: To determine CT features that can potentially differentiate right tubo-ovarian abscess (TOA) from acute appendicitis (AA; including abscess formation). MATERIALS AND METHODS: The abdominal computed tomography (CT) images of 48 patients with right-sided TOA (average age 39.3 ± 9.8 years) and 80 patients (average age 53.5 ± 19.9 years) with AA (24 with peri-appendicular abscess) were retrospectively evaluated. Two experienced radiologists evaluated 12 CT signs (including enlarged, thickened wall ovary, appendix diameter and wall thickness, peri-appendicular fluid collection, adjacent bowel wall thickening, fat stranding, free fluid, and extraluminal gas) in consensus to categorize the studies as either TOA or AA. The diagnosis and the frequency of each of the signs were correlated with the surgical and clinical outcome. RESULTS: Reviewers classified 92% cases correctly (TOA=85%, AA=96.3%), 3% incorrectly (TOA=6.3%, AA=1.3%); 5% were equivocal (TOA=8.3%, AA=2.5%). In the peri-appendicular abscess group reviewers were correct in 100%. Frequent findings in the TOA group were an abnormal ovary (87.5%), peri-ovarian fat stranding (58.3%), and recto-sigmoid wall thickening (37.5%). An abnormal appendix was observed in 2% of TOA patients. Frequent findings in the AA group were a thickened wall (32.5%) and distended (80%) appendix. Recto-sigmoid wall thickening was less frequent in AA (12.5%). The appendix was not identified in 45.8% of the TOA patients compared to 15% AA. CONCLUSIONS: In the presence of a right lower quadrant inflammatory mass, peri-ovarian fat stranding, thickened recto-sigmoid wall, and a normal appearing caecum, in young patients favour the diagnosis of TOA. An unidentified appendix does not contribute to the differentiation between TOA and peri-appendicular abscess.

Fetal Exposure to MR Imaging: Long-Term Neurodevelopmental Outcome.

BACKGROUND AND PURPOSE: Very few studies have investigated long-term neurodevelopment of children exposed to MR imaging antenatally. Thus, the purpose of our study was to evaluate long-term neurodevelopmental outcomes of children exposed to MR imaging during pregnancy. MATERIALS AND METHODS: We conducted a historical prospective cohort study in a single tertiary medical center. Women exposed to 1.5T noncontrast MR imaging for maternal or fetal indications were matched to unexposed controls. Long-term neurodevelopmental outcomes were evaluated of their children, 2.5 to 6 years of age, according to the Vineland-II Adaptive Behavior Scale. The Vineland-II Adaptive Behavior Scale assesses communication, daily living skills, socialization, and motor skills. A composite score summarizes these 4 domains. RESULTS: A total of 131 exposed women matched our inclusion criteria and were included in the study group, and 771 unexposed women, in the control group. No difference was identified in the Vineland-II Adaptive Behavior Scale composite score between the children of the study and control groups (mean, 110.79 versus 108.18; P = .098). Differences were also not observed between the children of the 2 groups in 3 of the 4 questionnaire domains: communication (108.84 versus 109.10; P = .888), daily living skills (109.51 versus 108.28; P = .437), and motor skills (105.09 versus 104.42; P = .642). However, the socialization score was favorable for the study group (112.98 versus 106.47; P < .001). CONCLUSIONS: Exposure to 1.5T noncontrast MR imaging during pregnancy had no harmful effects on long-term neurodevelopmental outcomes. This study contributes to understanding the safety of MR imaging during pregnancy.

Systematic review with meta-analysis: magnetic resonance enterography signs for the detection of inflammation and intestinal damage in Crohn's disease.

BACKGROUND: In the treatment of Crohn's disease (CD), mucosal healing has become a major goal, with the hope of avoiding intestinal damage from chronic inflammation. Magnetic resonance enterography (MRE) has emerged as a non-invasive means of monitoring inflammation and damage. AIMS: As part of the development of MRE-based multi-item measures of inflammation and damage for paediatric studies, we carried out a systematic review and meta-analysis to identify MRE variables used to describe these two distinct concepts. METHODS: 2501 studies of MRI and CD were identified. Studies written in any language reporting individual MRE signs for patients diagnosed with CD were included. Two-hundred-and-forty-four studies were fully reviewed and 62 were included (inflammation, n = 51; damage, n = 24). Sensitivity, specificity and associated confidence intervals were calculated, and hierarchical summary ROC curves were constructed for each MRE sign. RESULTS: A total of 22 MRE signs were used to reflect inflammation, and 9 to reflect damage. Diagnostic accuracy of MRE signs of inflammation and damage was heterogeneous; however, wall enhancement, mucosal lesions and wall T2 hyperintensity were the most consistently useful for inflammation (most sensitivities >80% and specificities >90%), and detection of abscess and fistula were most consistently useful for damage (most sensitivities >90%, specificities >95%). CONCLUSIONS: Identifying the best MRE variables to reflect inflammation and damage will maximise the utility of this rapidly emerging technique and is the first stage of constructing MRE-based indices for evaluating inflammation and intestinal damage.

Fat halo sign in the bowel wall of patients with Crohn's disease.

AIM: To evaluate the prevalence and localization of the deposition of submucosal fat, the "fat halo sign" (FHS), using computed tomography (CT) in the bowel wall of patients with Crohn's Disease, and to assess its relation to the duration of the disease. MATERIALS AND METHODS: The abdominal CT examinations of 100 consecutive patients were reviewed for the presence of the FHS in the bowel wall. A measurement of less than -10HU was regarded as indicative of fat. CT findings were correlated with the duration of the disease and statistically tested by simple regression analysis. The patients were divided into two groups: group A included 26 patients with a disease duration of less than 1 year and group B included 73 with a longer disease duration. In one patient disease duration was unknown. To test the relationship between disease duration and FHS the cumulative number of FHS positive and negative patients was plotted against disease duration. RESULTS: The FHS was present in 17 of the 100 patients in 20 bowel segments, mainly in the ileum (10) and the ascending colon (8). The FHS was present in 3.8% in group A and in 21.9% in group B (p<0.0375). CONCLUSION: The FHS was present in 17% of patients with CD. Its location was mainly in the terminal ileum and ascending colon, typical sites of the disease. Its prevalence was significantly duration dependent.