Use of a combined MR imaging and interventional radiology suite for intraprocedural monitoring of uterine artery embolization.
OBJECTIVE
The optimal embolic endpoint for uterine artery embolization (UAE) is unknown. It is difficult to quantify substasis endpoints with the use of conventional x-ray interventional radiology (IR) guidance. Although magnetic resonance (MR) imaging can detect perfusion changes, intraprocedural perfusion changes within targeted uterine leiomyomas and the remaining uterine wall remain unknown. A hybrid MR/IR unit was used to test the hypothesis that MR imaging can detect changes in uterine perfusion-dependent signal enhancement immediately after UAE.


METHODS
In this prospective study, UAE was performed in a hybrid MR/IR unit in women with symptomatic uterine leiomyomas. This MR/IR unit contains a wide-bore 1.5-T MR scanner connected by a sliding table to an adjacent x-ray digital subtraction angiography unit. Gadolinium-enhanced MR imaging was performed before and after UAE. Relative signal-to-noise ratio (SNR) was measured within each tumor and the adjacent uterine wall, and mean relative SNR changes were compared before and after UAE with the paired t test (alpha=0.05).


RESULTS
UAE was technically successful in all six women, in whom 10 tumors were assessed (seven intramural, two submucosal, one subserosal). Mean relative SNR of the tumors before UAE was 62.2+/-25.0 and was reduced to 41.1+/-17.7 after UAE (P<.01). Mean relative SNR of the adjacent uterine wall was 64.2+/-14.3 before UAE and decreased to 28.8+/-14.9 after UAE (P<.01).


CONCLUSIONS
Immediate reductions in perfusion-dependent enhancement in targeted uterine leiomyomas and the adjacent uterine wall can be detected during UAE with the use of a hybrid MR/IR unit. Further studies are now warranted to compare long-term clinical outcomes versus immediate changes in perfusion at the time of UAE.
Vin
Anita P
AP
Department of Radiology, Northwestern University Feinberg School of Medicine, 448 East Ontario Street, Suite 700, Chicago, Illinois 60611, USA.
Rhee
Thomas K
TK
Ryu
Robert K
RK
Larson
Andrew C
AC
Nikolaidis
Paul
P
Chrisman
Howard B
HB
Vogelzang
Robert L
RL
Omary
Reed A
RA
D000328:Adult; D001158:Arteries / Q000473:pathology*; D004621:Embolization, Therapeutic / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D007047:Hysterosalpingography / Q000379:methods; D007089:Image Enhancement / Q000295:instrumentation / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods; D008875:Middle Aged; D015641:Radiography, Interventional / Q000295:instrumentation* / Q000379:methods; D013382:Subtraction Technique / Q000295:instrumentation*; D014599:Uterus / Q000098:blood supply* / Q000473:pathology