An ultrasound-based imaging method that analyzes a woman’s pelvis from within is as effective as magnetic resonance imaging (MRI) to detect deep infiltrating endometriosis, a review study reveals.
The study “Transvaginal ultrasound vs magnetic resonance imaging for diagnosing deep infiltrating endometriosis: systematic review and meta‐analysis” was published in the journal Ultrasound in Obstetrics & Gynecology.
For decades the medical community has recognized a subclass of the disorder known as deep infiltrating endometriosis, which affects organs such as the bladder, parts of the vagina, and the intestine.
Several imaging methods have been suggested for the detection of these deep-infiltrating lesions, including ultrasound, computed tomography, and MRI.
In general, ultrasound with a transvaginal approach — in which the signals are read from within the vagina, producing images of the pelvic region from the inside — is considered as a first-line diagnostic method. However, there is no clear evidence confirming the diagnostic potential of transvaginal ultrasound (TVS) compared to other methods.
A team of Italian and Spanish researchers reviewed clinical data previously published on the diagnostic potential of MRI and TVS to detect deep infiltrating endometriosis lesions.
From a total of 375 studies published from January 1989 to October 2016, only six directly compared the two imaging methods. The selected six studies included data from a total of 424 women.
Pooled data revealed that both transvaginal ultrasound and MRI were able to detect with 85% sensitivity and 95-96% specificity deep infiltrating lesions affecting the last portion of the large intestine (the rectosigmoid).
Despite the similar diagnostic potential to detect endometriosis involving the rectosigmoid, transvaginal ultrasound results showed greater variability between studies.
“The data confirm that identification of endometriosis involving the rectosigmoid is very good using both transvaginal ultrasound and MRI,” the researchers wrote.
Next they evaluated the potential of the two imaging methods to detect deep infiltrating endometriosis involving the ligaments that connect the uterus to the sacral bone (uterosacral ligaments), and the rectovaginal septum.
Once more the diagnostic performance of the two methods was similar for both affected tissues, yet some variability in their specificity and/or sensitivity also was reported between studies.
Collectively, these results revealed that both imaging methods can similarly detect deep infiltrating endometriosis involving different tissues, “confirming the role of transvaginal ultrasound as a cost-effective first-line [diagnostic] technique,” the researchers said.
“We suggest that future studies use a standardized approach in order to decrease heterogeneity,” they added.