Apparent diffusion coefficient by magnetic resonance cholangiopancreatography is useful for grading cholecystitis and surgery planning.

INTRODUCTION: Laparoscopic cholecystectomy is a standard procedure for treating cholescytitis, but severe inflammation may cause complications. Our previous study showed that the apparent diffusion coefficient (ADC) values could predict difficult surgery. In the present study, relevance of ADC values in grading the severity of cholecystitis was pathologically investigated. METHODS: We retrospectively analyzed a total of 50 patients who underwent laparoscopic cholecystectomy or laparotomic cholecystectomy/choledocholithotomy. The degree of inflammation in the neck of the gall bladder was pathologically graded into three tiers (grade 1, mild; grade 2, moderate; grade 3, severe), and ulceration, lymphoid follicle formation, and wall thickness of the gallbladder neck were recorded. All factors were statistically compared with the measured ADC values. RESULTS: The ADC value was significantly lower in the severe inflammation group ( grade 3) than in the weak inflammation group (grades 1 and 2) (1.93 ± 0.22 vs 2.38 ± 0.67, respectively; P = .02). Ulceration and wall thickness in the gallbladder neck were significantly correlated with ADC values (P = .04 and .006, respectively), and lymphoid follicle formation was marginally correlated with ADC values (P = .06). The diagnostic utility of the ADC values decreased as the interval between imaging and cholecystectomy increased. [Correction added on 19 October 2022, after first online publication: [On the first sentence of the Results section, (grades 2 and 3) for weak inflammation group has been changed to (grades 1 and 2).] CONCLUSION: ADC values were inversely associated with the pathologic intensity of cholecystitis. We recommend that the ADC value be measured before surgery, so that the procedure can be accordingly planned.

Development of imaging biomarker for esophageal cancer using intravoxel incoherent motion MRI.

BACKGROUND: Intravoxel incoherent motion MRI (IVIM-MRI) can quantify micro-perfusion at the capillary level in the tissue. The purpose of this study is to measure tumor perfusion using IVIM-MRI, and evaluate its value as a biomarker to predict prognosis in esophageal squamous cell carcinoma (ESCC) patients. METHODS: 109 ESCC patients (93 men and 16 women; median age: 72) who underwent IVIM-MRI prior to treatment between February 2018 and August 2020 were retrospectively investigated. Both mean apparent diffusion coefficient (ADC) value and mean perfusion-related parameter (PP) value of the primary tumor were measured using three b values of 0, 400, and 1000 s/mm2 based on the IVIM model. We analyzed associations of these parameters with clinical stage and disease-specific survival (DSS). RESULTS: Lower ADC and PP values of the tumor were significantly associated with the higher clinical T stage (p < 0.0001, p < 0.0001, respectively). In Kaplan-Meier analyses, patients with lower PP value tumors (< 18.94, median) had significantly worse DSS (p < 0.0001), while tumor ADC value did not show a significant correlation with DSS. In a multivariate analysis, PP value of the tumor was an independent prognostic factor for DSS (p = 0.0027). CONCLUSIONS: Quantification of tumor perfusion using IVIM-MRI can be a non-invasive prognostic biomarker of ESCC, reflecting clinical stage and survival.