Ikink Marlijne E, Voogt Marianne J, van den Bosch Maurice A A J, Nijenhuis Robbert J, Keserci Bilgin, Kim Young-sun, Vincken Koen L, Bartels Lambertus W
Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands,
Eur Radiol. 2014 Sep;24(9):2118-27. doi: 10.1007/s00330-014-3274-y. Epub 2014 Jun 25.
To assess the value of diffusion-weighted magnetic resonance imaging (DWI) and apparent diffusion coefficient (ADC) mapping using different b-value combinations for treatment evaluation after magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) of uterine fibroids.
Fifty-six patients with 67 uterine fibroids were treated with volumetric MR-HIFU. Pre-treatment and post-treatment images were obtained using contrast-enhanced T1-weighted MRI (CE-T1WI) and DWI using b = 0, 200, 400, 600, 800 s/mm(2). ADC maps were generated using subsets of b-values to investigate the effects of tissue ablation on water diffusion and perfusion in fibroids treated with MR-HIFU. Four combinations of b-values were used: (1) all b-values; (2) b = 0, 200 s/mm(2); (3) b = 400, 600, 800 s/mm(2); and (4) b = 0, 800 s/mm(2).
Using the lowest b-values (0 and 200 s/mm(2)), the mean ADC value in the ablated tissue reduced significantly (p < 0.001) compared with baseline. Calculating the ADC value with the highest b-values (400, 600, 800 s/mm(2)), the ADC increased significantly (p < 0.001) post-treatment. ADC maps calculated with the lowest b-values resulted in the best visual agreement of non-perfused fibroid tissue detected on CE images. Other b-value combinations and normal myometrium showed no difference in ADC after MR-HIFU treatment.
A decrease in contrast agent uptake within the ablated region on CE-T1WI was correlated to a significantly decreased ADC when b = 0 and 200 s/mm(2) were used.
DWI could be useful for treatment evaluation after MR-HIFU of uterine fibroids. The ADC in fibroid tissue is influenced by the choice of b- values. Low b-values seem the best choice to emphasise perfusion effects after MR-HIFU.
评估使用不同b值组合的磁共振扩散加权成像（DWI）和表观扩散系数（ADC）图在磁共振引导下高强度聚焦超声（MR-HIFU）治疗子宫肌瘤后的疗效评估中的价值。
对56例患有67个子宫肌瘤的患者进行容积性MR-HIFU治疗。治疗前和治疗后使用对比增强T1加权磁共振成像（CE-T1WI）和b = 0、200、400、600、800 s/mm²的DWI获取图像。使用b值子集生成ADC图，以研究组织消融对MR-HIFU治疗的肌瘤中水扩散和灌注的影响。使用了四种b值组合：（1）所有b值；（2）b = 0、200 s/mm²；（3）b = 400、600、800 s/mm²；（4）b = 0、800 s/mm²。
使用最低的b值（0和200 s/mm²）时，与基线相比，消融组织中的平均ADC值显著降低（p < 0.001）。使用最高的b值（400、600、800 s/mm²）计算ADC值时，治疗后ADC显著增加（p < 0.001）。使用最低b值计算的ADC图在CE图像上检测到的无灌注肌瘤组织具有最佳的视觉一致性。其他b值组合和正常子宫肌层在MR-HIFU治疗后ADC无差异。
当使用b = 0和200 s/mm²时，CE-T1WI上消融区域内造影剂摄取的减少与ADC的显著降低相关。
DWI可用于子宫肌瘤MR-HIFU治疗后的疗效评估。肌瘤组织中的ADC受b值选择的影响。低b值似乎是强调MR-HIFU后灌注效应的最佳选择。
