MR imaging rounds out UAE patient management

MR imaging prior to fibroid embolization therapy can uncover pelvic pathology, including adenomyosis and endometrial lesions, that might result in a decision not to proceed with uterine artery embolization, researchers report.

The initial imaging modality for these patients has traditionally been ultrasound, which may have limitations in aiding the interventional radiologist's decision to embolize, said lead author Dr. Paul Nikolaidis, an assistant professor of radiology at Northwestern University Feinberg School of Medicine, at the American Roentgen Ray Society meeting held in May.

MR imaging offers several important advantages over ultrasound: multiplanar imaging capability, a larger field-of-view, better spatial resolution, and increased anatomic detail.

"High-quality MRI is the greatest single tool in managing patients undergoing embolization. As we get four and five years postembolization, the development of new fibroids begins to become a clinical issue, and it is very difficult to distinguish new fibroids from older infarcted fibroids without a good-quality contrast-enhanced MRI," said Dr. James B. Spies, a professor of radiology at Georgetown University and a noted expert on the subject.

Nikolaidis and colleagues evaluated 94 women referred for UAE who underwent pelvic MR examinations that included multiplanar T2-weighted fast spin-echo and pre- and postgadolinium fat-saturated gradient recall echo sequences. MR detected nonviable fibroids in 20% of the patients. Imaging revealed that UAE would not have been effective in six patients, due to one dominant or several large nonenhancing fibroids. In 11 patients, embolization was not recommended for various reasons, including fibroids that were either too large or too small, the presence of adenomyosis or endometrial lesions, and submucosal fibroids that required resection.

MR imaging is unique in its ability to easily assess fibroid enhancement and viability, Nikolaidis said. It can determine, for example, whether the fibroids are vascular and whether a reduction in the fibroids' blood supply would be beneficial. MR also better determines fibroids' location as submucosal, intramural, or subserosal. And it can evaluate the presence of other pelvic pathology such as adenomyosis, ovarian pathology, endometriosis, and other endometrial abnormalities.

In an attempt to validate decisions on whether to embolize, Nikolaidis and colleagues want to correlate long-term outcomes in these patients with their pre-embolization MR scans. They are assessing the MR features of uterine fibroids, using a variety of sequences, as well as the application of newer techniques such as perfusion imaging.