Diffusion-weighted imaging in uterine artery embolisation: do findings correlate with contrast enhancement and volume reduction?

Abstract

Objectives The objective of this study was to determine the role of diffusion-weighted imaging (DWI) in uterine artery embolisation (UAE), and to assess the apparent diffusion coefficient (ADC) of the dominant fibroid and its relationship to contrast enhancement and fibroid volume reduction. Methods We carried out a retrospective study of 15 patients who underwent UAE. Calculations were performed at baseline and 6 months post-embolisation. Fibroid ADC (expressed in 10−3 mm2 s−1) was calculated using b=0 and b=1000 DWI values. Fibroid enhancement was compared with background myometrium by measuring signal-difference-to-noise ratio (SDNR). Fibroid volume was calculated using a prolate ellipse formula. Results There was a significant reduction (p<0.001) in fibroid ADC at 6 months (0.48; standard deviation, SD=0.26) as compared with baseline (1.01; SD=0.39). No significant change (p=0.07) was identified in 6-month myometrial ADC (1.09; SD=0.28) as compared with baseline (1.24; SD=0.20). Moderately strong and significant positive correlation was identified between baseline ADC and 6-month percentage volume reduction of the fibroid (correlation=0.66, p=0.007). No correlation was identified between SDNR and ADC at baseline or 6 months (r=0.01, p=0.97 and r=−0.13, p=0.64, respectively) or SDNR and percentage volume reduction at 6 months (correlation r=0.18, p=0.51). Conclusion Baseline ADC of dominant fibroids shows a moderately strong correlation with subsequent volume reduction at 6 months following UAE. No correlation was identified between ADC values and contrast enhancement on the baseline or 6-month scans. Further prospective evaluation is needed before DWI can be utilised in clinical practice. Advances in knowledge DWI imaging may provide additional information about UAE and possibly help to predict uterine volume reduction.

Ineffectiveness of Magnetic Resonance Imaging Enhancement to Predict Fibroid Volume Reduction After Uterine Artery Embolization

“…Our fi ndings also suggest that ADC is an independent predictor of fi broid shrinkage. Fibroids with higher ADC values pre-UAE demonstrated greater shrinkage, which has been reported in other retrospective and prospective investigations (9,15,17). It is unclear what the degree of diff usion restriction of water molecules signifi es, but ADC provides some information about the molecular and/or cellular composition of masses including fi broids, and it may be useful in pre-UAE patient selection.…”

MRI enhancement predicting fibroid volume reduction to uterine artery embolization

“…Fibroids with higher ADC values pre-UAE demonstrated greater shrinkage, which has been reported in other retrospective and prospective investigations [9,15,17]. It is unclear what the degree of diffusion restriction of water molecules signifies, but ADC provides some information about the molecular and/or cellular composition of masses including fibroids, and it may be useful in pre-UAE patient selection.…”

Monitoring Leiomyoma Response to Uterine Artery Embolization Using Diffusion and Perfusion Indices from Diffusion-Weighted Imaging

“…Liapi et al evaluated 32 fibroids in 11 patients treated with UAE and found a significant drop in post-UAE ADC value across a follow-up interval of 99–239 days [ 9 ]. Ananthakrishnan et al also showed that post-UAE ADC measured from 15 patients was lower than pre-UAE ADC at 6-month follow-up [ 10 ]. Faye et al further studied the ADC changes in 27 fibroids in 17 patients at 1-week and 6-month follow-ups and reported a continued ADC decrease relative to pre-UAE measurement [ 11 ].…”

“…Faye et al further studied the ADC changes in 27 fibroids in 17 patients at 1-week and 6-month follow-ups and reported a continued ADC decrease relative to pre-UAE measurement [ 11 ]. Liapi et al and Ananthakrishnan et al proposed that the drop in ADC following UAE might depend on the acute microscopic changes like dehydration [ 9 , 10 ]. However, it should be emphasized that there may be progressive liquefaction of fibroids with increasing time between UAE and follow-up MRI [ 7 ].…”