Deep learning in magnetic resonance enterography for Crohn's disease assessment: a systematic review.

Crohn's disease (CD) poses significant morbidity, underscoring the need for effective, non-invasive inflammatory assessment using magnetic resonance enterography (MRE). This literature review evaluates recent publications on the role of deep learning in improving MRE for CD assessment. We searched MEDLINE/PUBMED for studies that reported the use of deep learning algorithms for assessment of CD activity. The study was conducted according to the PRISMA guidelines. The risk of bias was evaluated using the QUADAS-2 tool. Five eligible studies, encompassing 468 subjects, were identified. Our study suggests that diverse deep learning applications, including image quality enhancement, bowel segmentation for disease burden quantification, and 3D reconstruction for surgical planning are useful and promising for CD assessment. However, most of the studies are preliminary, retrospective studies, and have a high risk of bias in at least one category. Future research is needed to assess how deep learning can impact CD patient diagnostics, particularly when considering the increasing integration of such models into hospital systems.

Qualitative sonographic assessment of transmural ileal inflammation in Crohn's disease: a comparison with MRI activity score.

BACKGROUND: Intestinal ultrasound (IUS) is an accurate tool for monitoring Crohn's disease. To date, there is no clinically used validated quantitative ultrasonographic score for assessing disease activity. For magnetic resonance enterography (MRE), the magnetic resonance index of activity (MaRIA) is most used. The goal of this study was to devise a new quantitative IUS score for assessing Crohn's disease inflammation, by using a partial MaRIA score as a reference. METHODS: This was a retrospective cohort study. The study cohort included patients with Crohn's disease followed between January 2016 and December 2018. Inclusion criteria were age >18 and <3 months between MRE and IUS. Linear/logistic regression was performed for the correlation of ultrasonographic parameters with MaRIA score. Ultrasonograpic features included: bowel wall thickness, disrupted bowel wall stratification, mesenteric fat proliferation, presence of lymph nodes, hypervascularity present on color Doppler flow, and the presence of complications (strictures, inflammatory mass, and fistula). RESULTS: Forty-two patients were included. A stepwise multiple regression model was constructed to predict MaRIA score using ultrasound features. Two variables were found to be independently significant: terminal ileum (TI) thickness (r = 0.68, P = 0.001) and mesenteric fat proliferation (r = 0.45, P = 0.019). A model was constructed as follows: MaRIA = 7 + 2.5 * TI US thickness (mm) + 7 * US fat proliferation (0 = no, 1 = yes). This model has an R2 of 0.51 for explaining the variability in the results. CONCLUSIONS: IUS measurements are significantly correlated with MaRIA score in the terminal ileum and a simple computational model can be constructed.

Simple Endoscopic Score of Crohn Disease and Magnetic Resonance Enterography in Children: Report From ImageKids Study.

OBJECTIVES: We aimed to explore the ability of magnetic resonance enterography (MRE) to impute the simple endoscopic score of Crohn disease (SES-CD) in children with CD, in whom failure of ileal intubation is common and may impair SES-CD calculation in clinical studies. METHODS: This is a substudy of the prospective ImageKids study in which children with CD underwent ileocolonoscopy (scored by SES-CD) and MRE (scored on a 100 mm visual analogue scale [VAS] and by MaRIA). Mucosal healing (MH) was defined as SES-CD <3, MRE-VAS <20 mm, and/or MaRIA <7. RESULTS: A total of 237 children (22 centers, age 11.5 ±â€Š3.3 years), were enrolled. Ileal intubation has failed in 40 of 237 (17%). The agreement between SES-CD and MRE was 75% (k = 0.508, P < 0.001) in the ileum, and 68% to 85% in the colonic segments (k = 0.21-0.50, P < 0.001). The sensitivity and specificity of ileal MRE-VAS for MH were 91.7% (95% confidence interval 0.84-0.96) and 53.1% (95% confidence interval 0.43-0.63), respectively. The ileal MaRIA score (calculated in 33/40) was higher in the children without ileal intubation than in the others (20.5 ±â€Š7.1 vs 15.1 ±â€Š10.8, respectively, P = 0.0018). In 7% (16/237) of children, isolated active ileal disease would have been missed when considering SES-CD only. A multivariable model predicted the ileal SES-CD subscore from the MaRIA: SES-CDileum = 1.145 + 0.169 × MaRIAileum rounded to the nearest whole number (R = 0.17). Applying this model to the children without ileal intubation revealed that 29 of 33 (88%) had ileal disease; 8 of 29 patients (28%) with normal colonic SES-CD had imputed ileal SES-CD ≥3. CONCLUSIONS: MRE is useful for imputing the ileal disease in pediatric clinical studies, overcoming the problem of ileal nonintubation.

Assessment of patency capsule retention using MR diffusion-weighted imaging.

OBJECTIVES: Evaluate the ability of MR diffusion-weighted imaging (DWI) to predict patency capsule retention in Crohn's disease (CD). METHODS: Clinical and imaging data were prospectively reviewed for 80 CD patients following patency capsule administration and MR-DWI under institutional review board (IRB) approval with informed consent. Two radiologists separately assessed the presence/absence of restricted diffusion in the distal ileum. Apparent diffusion coefficients (ADC) from three regions of interest on the ileal wall were averaged. The association between restricted diffusion and retention, and sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated. Ability of ADC to predict retention was assessed with receiver operating characteristic (ROC) curve analysis. RESULTS: Restricted diffusion in the distal ileum was associated with capsule retention (p = 0.001, p < 0.0001). Sensitivity, specificity, PPV and NPV of restricted diffusion for capsule retention were 100.0%, 46.2%, 30.0%, 100% and 100.0%, 56.9%, 34.9%, 100%, respectively, for two radiologists. Accuracy of ADC to predict retention was high (area under the curve = 0.851, p < 0.0001). An ADC of 1.47 mm2/s showed 90.0% sensitivity and 50.0% specificity for retention. CONCLUSIONS: Sensitivity and NPV of restricted diffusion for patency capsule retention were 100%, suggesting that DWI may predict gastrointestinal tract capability to pass video camera endoscopy. KEY POINTS: • Capsule endoscopy enables assessment of the gastrointestinal mucosa in Crohn's disease • Prior patency capsule administration is recommended to evaluate gastrointestinal tract patency • MR diffusion-weighted imaging may detect pathological constriction of the ileum • Restricted diffusion in the distal ileum was associated with capsule retention • MR-DWI may predict gastrointestinal tract capability to pass capsule endoscopy.

The Role of Liver Segment-to-Spleen Volume Ratio in the Staging of Hepatic Fibrosis in Patients with Hepatitis C Virus Infection.

BACKGROUND: Accurate assessment of liver fibrosis is crucial for the management of patients with hepatitis C virus (HCV) infection. OBJECTIVES: To evaluate the performance of liver segment-to-spleen volume ratio in predicting the severity of liver fibrosis. METHODS: Sixty-four consecutive HCV patients were enrolled in this retrospective study. All patients underwent contrast-enhanced computed tomography (CT) and were divided into three groups based on their hepatic fibrosis stage evaluated by shear-wave elastography (SWE): non-advanced (F0-F1, n=29), advanced (F2, n=19) and severe fibrosis (F3-F4, n=16). Using semi-automated liver segmentation software, we calculated the following liver segments and spleen volumes for each participant: total liver volume (TLV), caudate lobe (CV), left lateral segment (LLV), left medial segment (LMV), right lobe (RV) and spleen (SV), a well as their ratios: CV/SV, RV/SV, LLV/SV, LMV/SV and TLV/SV. RESULTS: RV/SV was found to discriminate between patients with non-advanced and advanced fibrosis (P = 0.001), whereas SV, CV, RV, TLV/SV, LMV/SV and RV/SV discriminated between patients with advanced and severe fibrosis (P < 0.05). RV/SV ≤ 3.6 and RV ≤ 2.9 were identified as the best cutoff values to differentiate non-advanced from advanced fibrosis and advanced from severe fibrosis with sensitivities of 72.2% and 92.7%, specificities of 72.7% and 77.8%, and with an area under the receiver operating characteristic (ROC) curve of 0.797 and 0.847, respectively (P ≤ 0.002). CONCLUSIONS: RV/SV may be used for the assessment and monitoring of liver fibrosis in HCV patients prior to the administration of antiviral therapy, considering SWE as the reference method.

Colonic perforation at CT colonography: assessment of risk in a multicenter large cohort.

PURPOSE: To assess retrospectively the incidence, clinical features, and treatment of colonic perforation at computed tomographic (CT) colonography in a large multicenter cohort. MATERIALS AND METHODS: The study was performed in accordance with the institutional ethics committees' requirements of a retrospective review in each of the participating centers, and no informed consent was required. A review of all patients who underwent CT colonography between January 2001 and December 2004 in 11 medical centers representing more than 95% of studies performed in a single country was performed to determine the rate of colorectal perforation. Data about patient demographics and patient- and procedure-related risk were recorded. Information about the location of the perforation, its likely mechanism, and treatment was collected. Analysis included calculation of rates of colonic perforation and surgical treatment and of 95% confidence intervals. RESULTS: A total of 11 870 CT colonographic studies were performed in 6837 (57.6%) men and 5033 (42.4%) women (mean age, 59.9 years; range, 38-90 years) with seven cases of colorectal perforation, yielding a risk rate of 0.059% (one of 1696 studies; 95% confidence interval: one of 974, 971 of 6537). The mean age of the patients with perforation was 77.8 years. Six (84%) of seven cases of perforation occurred in symptomatic patients at high risk for colorectal neoplasia, and one (16%) occurred in an asymptomatic average-risk patient. All studies were performed after insufflation of room air. Six (84%) cases of perforation occurred in patients in whom a rectal tube was inserted, and in five of them, a balloon was inflated. Five (71%) cases of perforation occurred in the sigmoid colon; and two (29%), in the rectum. Four (57%) patients (one in 2968 patients; 95% confidence interval: 1.5 in 10 000, 14.7 in 10 000) required surgical treatment. Possible factors that contributed to perforation were left inguinal hernia containing colon (n = 4), severe diverticulosis (n = 3), and obstructive carcinoma (n = 1). CONCLUSION: Perforation of the colon and rectum is a rare complication of CT colonography. Older age and underlying concomitant colonic disease were present in patients with perforation.