Quantitative diffusion-weighted magnetic resonance enterography in ileal Crohn's disease: A systematic analysis of intra and interobserver reproducibility

Abstract

BACKGROUND Magnetic resonance enterography (MRE) is increasingly attractive as a noninvasive and radiation-free tool for assessing Crohn’s disease (CD). Diffusion-weighted imaging (DWI) is recommended as an optional MRE sequence for CD by the European Society of Gastrointestinal and Abdominal Radiology, and has shown a superb potential as a quantitative modality for bowel inflammation evaluation. However, the measurement reproducibility of quantitative DWI analysis in MRE has not been ascertained so far. To facilitate the application of quantitative diffusion-weighted MRE in the clinical routine, systematic investigations of the intra and interobserver reproducibility of DWI quantitative parameters should be performed. AIM To evaluate the intra and interobserver reproducibility of quantitative analysis for diffusion-weighted MRE (DW-MRE) in ileal CD. METHODS Forty-four subjects (21 with CD and 23 control subjects) who underwent ileocolonoscopy and DW-MRE (b = 800 s/mm 2 ) within one week were included. Two radiologists independently measured apparent diffusion coefficients (ADC) of the terminal ileum and signal intensity ratio (SR) of the terminal ileum to ipsilateral psoas muscle on DWI images (b = 800 s/mm 2 ). Between- and within-reader agreements were assessed using intraclass correlation coefficients (ICC), coefficients of variation (CoV), and 95% limits of agreement of Bland-Altman plots (BA-LA LoA). Diagnostic performances of ADC and SR for identifying inflamed terminal ileum from the normal were evaluated by receiver operating characteristic (ROC) curve analysis. RESULTS There were no significant differences in ADC or SR values between the two sessions or between the two radiologists either in the CD or control group (paired t -test, P > 0.05). The intra and interobserver reproducibility of ADC (ICC: 0.952-0.984; CoV: 3.73-6.28%; BA-LA LoA: ±11.27% to ±15.88%) and SR (ICC: 0.969-0.989; CoV: 3.51%-4.64%; BA-LA LoA: ±10.62% to ±15.45%) was excellent for CD. Agreement of ADC measurements was slightly less in control subjects (ICC: 0.641-0.736; CoV: 10.47%-11.43%; BA-LA LoA: ± 26.59% to ± 30.83%). SR of normal terminal ileum demonstrated high intra and interobserver reproducibility (ICC: 0.944-0.974; CoV: 3.73%-6.28%; BA-LA LoA: ± 18.58% to ± 24.43%). ADC and SR of two readers had outstanding diagnostic efficiencies (area under the ROC curve: 0.923-0.988). CONCLUSION Quantitative parameters derived from DW-MRE have good to excellent intra and interobserver agreements with high diagnostic accuracy, and can serve as robust and efficient quantitative biomarkers for CD evaluation.

Role of abbreviated non-contrast-enhanced MR-enterography in the evaluation of Crohn's disease activity and complications as an alternative for full protocol contrast-enhanced study: A systematic review and meta-analysis

“… CE T1w MRE can be replaced by DWI. Yu, 2019 [67] DWI and ADC ileocolonoscopy terminal ileum active inflammation n/s ADC and ileum to psoas signal SR both showed high reproducibility (ICC=0.952 and ICC=0.969) ADC: 85.7% Sens and 95.7% Spec SR: up to 95.2% Sens and 95.7% Spec SR and ADC values can quantitatively diagnose the presence of active CD lesions. SR has better sensitivity.…”

“…ROC: the receiver operating characteristics. Study Reference test ADC threshold ( /s) AUC Sensitivity Specificity Yang, 2019 [42] ileocolonoscopy 0.87 0.924 0.906 0.936 Li, 2015 [19] clinical score 1.12 0.98 1 0.88 Strakšyte, 2020 [60] ileocolonoscopy 1.32 0.883 0.979 0.978 Abd-El Khalek, 2018 [72] CE-MRE 1.38 n/s 0.93 0.9 Schmid-Tannwald, 2016 [79] histopathology 1.41 0.95 0.93 0.75 Soydan, 2019 [68] ileocolonoscopy 1.47 0.729 0.885 0.657 Huang, 2018 [41] CE-MRE 1.485 0.907 0.864 0.9 Stanescu-Siegmund, 2017 [76] CE-MRE, clinical scoring 1.56 0.998 0.974 0.992 Li, 2017 [75] ileocolonoscopy 1.59 0.974 0.972 0.843 Yu, 2019 [67] ileocolonoscopy 1.81 0.929 0.857 0.957 Hordonneau, 2014 [88] CE-MRE 1.9 n/s 0.937 ...…”

Repeatability of Magnetic Resonance Measurements Used for Estimating Crohn’s Disease Activity

“…The quality of DWI images is therefore lesser than that of conventional MR images, due to low resolution, noise, distortions, and limited morphological interpretability (Chilla et al, 2015); therefore, DWI provides functional rather than anatomical information. Opinions on reproducibility of ADC-DWI measurements used in the Clermont score varies among authors, and despite good to excellent repeatability reported from certain authors (Yu et al, 2019), contrary concerns on low reproducibility based on research data also exist (Watson et al, 2018). Due to equivocal data on repeatability of measurements the form the MaRIA and Clermont score, our interest was to assess the repeatability of measurements contributing to both of these indices -WSI-preGd and WSI-postGD forming RCE in MaRIA, ADC-DWI used in the Clermont score, as well as bowel thickness and estimation of presence of bowel ulcers, which are common to both MaRIA and Clermont scores.…”

Radiologische Diagnostik chronisch-entzündlicher Darmerkrankungen bei Kindern und Jugendlichen

“…Einige Studien haben sich mit der DWI als potenziellem Biomarker beschäftigt, und es wurde versucht, potenzielle "Apparent-diffusion-coeffi- cient"(ADC)-Grenzwerte zu definieren, mit deren Hilfe evtl. zwischen unterschiedlichen Stadien der Entzündung differenziert werden kann [2,39]. Anhand dieses Prinzips kann das DWI auch zur Beurteilung des Therapieansprechens hilfreich sein [12].…”