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

Non-invasive staging of endometrial fibrosis using diffusion-weighted imaging: a feasibility study

RESEARCH QUESTION

Can diffusion-weighted imaging (DWI) be used to stage endometrial fibrosis?

DESIGN

This prospective study included 41 healthy women, 30 patients with mild to moderate endometrial fibrosis (MMEF) and 102 patients with severe endometrial fibrosis (SEF). Endometrial thickness and DWI-related parameters, specifically the mean intensity (ADCROI and ADCVOI) and standard deviation (ADC-SDROI and ADC-SDVOI) of the endometrial apparent diffusion coefficient (ADC) values within a region of interest (ROI) on a mid-sagittal ADC map, and volume of interest (VOI) of the entire endometrium in the corpus uteri, were measured and analysed.

RESULTS

Endometrial thickness, endometrial ADCVOI and ADCROI were significantly higher in healthy women (11.7 mm, 1.31  ×  10-3 mm2/s and 1.36  ×  10-3 mm2/s) than MMEF patients (7.5 mm, P < 0.001; 1.23  ×  10-3 mm2/s, P = 0.001; and 1.26  ×  10-3 mm2/s, P = 0.003) and SEF patients (6.2 mm, 1.15  ×  10-3 mm2/s and 1.23  ×  10-3 mm2/s; all P < 0.001). Endometrial ADC-SDVOI and ADC-SDROI were significantly higher in SEF patients (0.24 and 0.24) than healthy women (0.16 and 0.13) and MMEF patients (0.18 and 0.16) (all P < 0.001). The degree of endometrial fibrosis was negatively correlated with endometrial thickness, endometrial ADCVOI and ADCROI (Spearman's rho = -0.662, -0.526 and -0.349) and positively correlated with endometrial ADC-SDVOI and ADC-SDROI (Spearman's rho 0.729 and 0.713) (all P < 0.001). Compared with endometrial thickness measurements, endometrial magnetic resonance imaging parameters, particularly DWI-related parameters, demonstrated excellent accuracy in distinguishing normal endometrium, MMEF and SEF (areas under the curve >0.800).

CONCLUSIONS

DWI is particularly effective for accurately staging the microstructural changes associated with endometrial fibrosis.

Multimodal MRI for Estimating Her-2 Gene Expression in Endometrial Cancer

PURPOSE

To assess the value of multimodal MRI, including amide proton transfer-weighted imaging (APT), diffusion kurtosis imaging (DKI), and T2 mapping sequences for estimating human epidermal growth factor receptor-2 (Her-2) expression in patients with endometrial cancer (EC).

METHODS

A total of 54 patients with EC who underwent multimodal pelvic MRI followed by biopsy were retrospectively selected and divided into the Her-2 positive (n = 24) and Her-2 negative (n = 30) groups. Her-2 expression was confirmed by immunohistochemistry (IHC). Two observers measured APT, mean kurtosis (MK), mean diffusivity (MD), and T2 values for EC lesions.

RESULTS

The Her-2 (+) group showed higher APT values and lower MD and T2 values than the Her-2 (-) group (all p < 0.05); there was no significant difference in MK values (p > 0.05). The area under the receiver operating characteristic curve (AUC) of APT, MD, T2, APT + T2, APT + MD, T2 + MD, and APT + MD + T2 models to identify the two groups of cases were 0.824, 0.695, 0.721, 0.824, 0.858, 0.782, and 0.860, respectively, and the diagnostic efficacy after combined APT + MD + T2 value was significantly higher than those of MD and T2 values individually (p = 0.018, 0.028); the diagnostic efficacy of the combination of APT + T2 values was significantly higher than that of T2 values separately (p = 0.028). Weak negative correlations were observed between APT and T2 values (r = -0.365, p = 0.007), moderate negative correlations between APT and MD values (r = -0.560, p < 0.001), and weak positive correlations between MD and T2 values (r = 0.336, p = 0.013). The APT values were independent predictors for assessing Her-2 expression in EC patients.

CONCLUSION

The APT, DKI, and T2 mapping sequences can be used to preoperatively assess the Her-2 expression in EC, which can contribute to more precise treatment for clinical preoperative.

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.