Quantification of Endometrial Fibrosis Using Noninvasive MRI T2 Mapping: Initial Findings.

BACKGROUND: Endometrial fibrosis may cause infertility. Accurate evaluation of endometrial fibrosis helps clinicians to schedule timely therapy. PURPOSE: To explore T2 mapping for assessing endometrial fibrosis. STUDY TYPE: Prospective. POPULATION: Ninety-seven women with severe endometrial fibrosis (SEF) and 21 patients with mild to moderate endometrial fibrosis (MMEF), diagnosed by hysteroscopy, and 37 healthy women. FIELD STRENGTH/SEQUENCE: 3T, T2-weighted turbo spin echo (T2-weighted imaging) and multi-echo turbo spin echo (T2 mapping) sequences. ASSESSMENT: Endometrial MRI parameters (T2, thickness [ET], area [EA], and volume [EV]) were measured by N.Z. and Q.H. (9- and 4-years' experience in pelvic MRI) and compared between the three subgroups. A multivariable model including MRI parameters and clinical variables (including age and body mass index [BMI]) was developed to predict endometrial fibrosis assessed by hysteroscopy. STATISTICAL TESTS: Kruskal-Wallis; ANOVA; Spearman's correlation coefficient (rho); area under the receiver operating characteristic curve (AUC); binary logistic regression; intraclass correlation coefficient (ICC). P value <0.05 for statistical significance. RESULTS: Endometrial T2, ET, EA, and EV of MMEF patients (185 msec, 8.2 mm, 168 mm2 , and 2181 mm3 ) and SEF patients (164 msec, 6.7 mm, 120 mm2 , and 1762 mm3 ) were significantly lower than those of healthy women (222 msec, 11.7 mm, 316 mm2 , and 3960 mm3 ). Endometrial T2 and ET of SEF patients were significantly lower than those of MMEF patients. Endometrial T2, ET, EA, and EV were significantly correlated to the degree of endometrial fibrosis (rho = -0.623, -0.695, -0.694, -0.595). There were significant strong correlations between ET, EA, and EV in healthy women and MMEF patients (rho = 0.850-0.908). Endometrial MRI parameters and the multivariable model accurately distinguished MMEF or SEF from normal endometrium (AUCs >0.800). Age, BMI, and MRI parameters in univariable analysis and age and T2 in multivariable analysis significantly predicted endometrial fibrosis. The reproducibility of MRI parameters was excellent (ICC, 0.859-0.980). DATA CONCLUSION: T2 mapping has potential to noninvasively and quantitatively evaluate the degree of endometrial fibrosis. EVIDENCE LEVEL: 2 Technical Efficacy: Stage 2.

Evaluation of Chronic Pancreatitis With T1 ρ MRI: A Preliminary Study.

BACKGROUND: Chronic pancreatitis (CP) can result in persistent damage to the endocrine and exocrine tissues of the pancreas. There is an unmet need for quantitative methods to evaluate CP noninvasively. PURPOSE: To investigate the utility of T1 ρ magnetic resonance imaging (MRI) for the assessment of CP. STUDY TYPE: Prospective. POPULATION: Twenty patients with CP and 24 healthy volunteers. FIELD STRENGTH/SEQUENCE: 3T MRI including T1 ρ sequence (spin lock time = 0, 1, 10, 20, 40, 60 msec). ASSESSMENT: Pancreatic T1 ρ values and anterior-posterior (AP) diameters in the head, body, and tail were measured in all participants. Regions of interest with circle (ROIcircle ) and free-hand (ROIFH ) were drawn for T1 ρ value measurements. STATISTICAL TESTS: Mann-Whitney U-test; Wilcoxon Signed Ranks test; receiver operating characteristic (ROC) curve; and Bland-Altman analysis. RESULTS: The T1 ρ values of pancreatic tail and the mean T1 ρ values for ROIcircle and the T1 ρ values of pancreatic tail for ROIFH in patients with CP were significantly higher than those in healthy volunteers (all P < 0.05). Pancreatic head AP diameter significantly increased, while pancreatic tail AP diameter significantly decreased in patients with CP compared with healthy volunteers (both P < 0.05). The areas under the ROC curves (AUCs) of pancreatic tail T1 ρ values with ROIcircle and tail AP diameter in diagnosing CP were 0.744 and 0.798, respectively. A combination of pancreatic tail T1 ρ values with ROIcircle and tail AP diameter achieved good performance for diagnosing CP (AUC = 0.838). DATA CONCLUSION: T1 ρ MRI might be a potential technique for the noninvasive evaluation of CP. Level of Evidence 2 Technical Efficacy Stage 2 J. MAGN. RESON. IMAGING 2021;53:577-584.

Initial Experience With Diffusion-Weighted Magnetic Resonance Imaging for the Evaluation of Endometrial Fibrosis.

OBJECTIVE: This study aimed to determine the feasibility of diffusion-weighted imaging for detecting endometrial fibrosis in patients with intrauterine injury. METHODS: This prospective study included 34 patients with endometrial fibrosis and 34 healthy controls. All participants underwent T2-weighted and diffusion-weighted magnetic resonance imaging with b values of 0 and 1000 s/mm2 during the periovulatory phase with a dominant follicle. The endometrial apparent diffusion coefficient (ADC) and uterine anatomical parameters (endometrial thickness [EMT], length of the uterine cavity [LUC], and junctional zone thickness [JZT]) were measured and compared. Performance of the uterine endometrial ADC and anatomical parameters in diagnosing endometrial fibrosis was evaluated. RESULTS: Patients with endometrial fibrosis showed a lower endometrial ADC, lower EMT, shorter LUC, and higher JZT than did healthy controls (all, P < 0.001). Endometrial ADC value and uterine anatomical parameters showed good performance in diagnosing endometrial fibrosis, with the areas under the receiver operating characteristic curves of 0.976, 0.870, 0.883, and 0.864, respectively. The area under the curve of ADC was significantly higher than those of EMT (z = 1.973, P = 0.0485), LUC (z = 2.059, P = 0.0395), and JZT (z = 2.484, P = 0.0130). Intraobserver and interobserver agreements of endometrial ADC value measurements were excellent for both patients (intraclass correlation coefficient = 0.987 and 0.983, respectively) and healthy women (intraclass correlation coefficient = 0.986 and 0.989, respectively). CONCLUSIONS: Our preliminary results suggest that diffusion-weighted imaging has the potential to be a noninvasive imaging tool for the quantitative assessment of endometrial fibrosis.

Diffusion kurtosis imaging for assessing endometrial fibrosis: a preliminary clinical study.

PURPOSE: To investigate the feasibility of using diffusion kurtosis imaging (DKI) for the assessment of endometrial fibrosis. METHODS: 40 patients with hysteroscopy confirmed endometrial fibrosis and 30 healthy women underwent MR examination including the DKI sequence (b = 0, 500, 1000, 1500, and 2000 s/mm2). Endometrial thickness (ET), apparent diffusion coefficient (ADC), corrected ADC (D), and kurtosis of diffusion (K) were measured and compared, and the diagnostic performance of those parameters was evaluated using ROC curves analysis. RESULTS: Patients with endometrial fibrosis had a thinner endometrium than the healthy controls (P < 0.001). They also had significantly lower ADC and D values and significantly higher K values of the endometrium than the healthy controls (all P < 0.001). ADC, D, K, and ET all performed excellently in diagnosing endometrial fibrosis, with areas under the curve (AUCs) of 0.940, 0.879, 0.860, and 0.853, respectively. ADC showed the highest AUC, demonstrating better diagnostic accuracy than K (z = 2.307, P < 0.05). However, there were no differences in AUC between D, K, and ET, or ADC, D, and ET (all P > 0.05). The reproducibility of ADC, D, and K values in patients with endometrial fibrosis and healthy controls was excellent (ICC 0.951-0.991). CONCLUSION: DKI of the endometrium has promising potential for the noninvasive assessment of endometrial fibrosis.

Noninvasive assessment of endometrial fibrosis in patients with intravoxel incoherent motion MR imaging.

Recently, few noninvasive methods have been reported to evaluate endometrial fibrosis. Our study was to investigate the feasibility of intravoxel incoherent motion (IVIM) MR imaging in the detection of endometrial fibrosis in patients with intrauterine injury. 30 patients with hysteroscopy-confirmed endometrial fibrosis and 28 healthy women were enrolled to undergo MR examination including the IVIM sequence. Endometrial thickness (ET); apparent diffusion coefficient (ADC); and IVIM parameters, including pure diffusion coefficient (D), pseudodiffusion coefficient (D*) and vascular fraction (f) were evaluated. A multivariable model combing ADC, D, and f values using binary logistic regression analysis was built to diagnose endometrial fibrosis. Endometrial fibrosis patients demonstrated lower endometrial ADC, D, f values and ET (all p < 0.05). The multivariable model, ADC, D, f values and ET performed well in diagnosing endometrial fibrosis with AUC of 0.979, 0.965, 0.920, 0.901 and 0.833, respectively. The multivariable model revealed a better diagnostic accuracy than D, f and ET (all p < 0.05). Although ADC achieved a better diagnostic value than ET (z = 2.082, p < 0.05), no difference in AUC was shown among ADC, D, and f (all p > 0.05); between ET and D (p > 0.05); and between ET and f (p > 0.05). The reproducibility of ADC, D, f and D* values in patients with endometrial fibrosis and healthy women were good to excellent (ICC: 0.614-0.951). IVIM parameters exhibit promising potential to serve as imaging biomarkers in the noninvasive assessment of endometrial fibrosis.