By measuring the water movement within the destroyed fibroid cells with DWI, the researchers hoped to better gauge the impact of treatment on the fibroids by using a quantitative biophysical parameter called the apparent diffusion coefficient (ADC).

Currently, treatment success is determined using regular MRI with a contrast agent. However, the image produced during this procedure does not precisely show functional information on the degree of fibroid destruction. Therefore, physicians also rely on questionnaires administered to patients after their fibroid treatment, which often are very subjective and unreliable.

In the study, 14 patients with uterine fibroids received ultrasound treatment and subsequent MR imaging using three different MR techniques: conventional MRI, MRI with contrast material, and DWI MRI. Results showed significantly greater signal intensity on DWI of ultrasound treated fibroids than on the images of untreated fibroids or treated fibroids obtained with the other MR methods.

These results were confirmed in the twelve patients who took part in the six-month follow up study. Also observed were differences in the ADC. The DWI technique was able to map the ADC in fibroids, showing lower ADC values in treated fibroids than in surrounding tissue, a measure of restricted cellular water flow due to the ultrasound treatment.

“While these results are preliminary and more research is needed, they strongly suggest that the diffusion-weighted MR technique provides images that show functional changes and the extent of fibroid damage from treatment. DWI may be useful for monitoring the effects of ultrasound treatment on uterine fibroids,” says Michael Jacobs, Ph.D., assistant professor of radiology and oncology at Johns Hopkins.; Source: Johns Hopkins Medical Institutions