Can a T2 hyperintense rim sign differentiate uterine leiomyomas from other solid adnexal masses?

Use of diffusion-weighted imaging in the noninvasive diagnostic of obstructed biliary ducts

OBJECTIVE

This study sought to evaluate the role of diffusion-weighted imaging (DWI) in differentiation between obstructed and unobstructed bile ducts in patients undergoing magnetic resonance imaging (MRI).

METHODS

Eighty-four patients, 40 males and 44 females (mean age: 56.4 ± 15.1 years), undergoing MRI with DWI (0-50-500-700) were evaluated and divided into two groups: 58 with abnormal laboratory tests (obstructed group) and 26 with normal laboratory values (unobstructed group). Laboratory tests were total bilirubin, alkaline phosphatase, and gamma-glutamyltransferase. Median ADC values were calculated and correlated with laboratory tests and degree of bile-duct dilatation (absent, moderate, or severe). The persistence of signal on DWI (b500 and b700) in the biliary tract was evaluated. Bilirubin values were tested for correlation with bile-duct ADC values and persistence of b700 signal. For statistical analysis, Student t test, chi-square test and Wilcoxon-Mann-Whitney test were used. ADC maps were plotted for three levels of the biliary tree, and a receiver operating characteristic (ROC) curve was calculated.

RESULTS

In the obstructed group, 15 patients had severe dilatation, 24 had moderate dilatation, and 19 had no appreciable dilatation; 38 patients had persistent signal on b700 images. In the unobstructed group, 23 patients had no dilatation and 3 had moderate dilatation; 4 patients had persistent signal on b700 images. Correlation was found between degree of bile-duct dilatation, bilirubin levels, persistence of b700 signal, and ADC map values. The calculated ADC map cutoff value (353 10^-6 mm²/s) was able to differentiate the obstructed and unobstructed groups with 92.3% sensitivity, 81% specificity, and 91.9% accuracy.

CONCLUSIONS

DWI is able to distinguish patients with obstructed versus unobstructed bile ducts, regardless of the degree of dilatation, correlating with clinical and laboratory findings.

Imaging techniques for evaluation of uterine myomas

Due to their high prevalence and related morbidity, uterine myomas constitute a group of gynecological pathologies largely studied in all clinical, diagnostic, and therapeutic aspects. They have been widely evaluated with a large series of imaging techniques. In fact, ultrasound (also saline infusion sonohysterography) and magnetic resonance imaging (MRI) are considered the optimal methods to assess uterine fibroids in terms of number, volume, echostructure, location, relation with endometrial cavity and uterine layers, vascularization, and differential diagnosis with other benign (adenomyosis) and malignant myometrial pathologies. Nevertheless, further studies are required to fill some gaps such as the absence of a common and sharable sonographic terminology and methodology to scan the myometrium, as well as imaging parameters for differentiation of typical myomas from smooth tumors of unknown malignant potential (STUMP) and leiomyosarcomas.