Öcal Osman, Dietrich Olaf, Lentini Sergio, Bour Pierre, Faller Thibaut, Ozenne Valery, Maier Florian, Fabritius Matthias Philipp, Puhr-Westerheide Daniel, Schmidt Vanessa F, Öcal Elif, Seidensticker Ricarda, Wildgruber Moritz, Ricke Jens, Seidensticker Max
Department of Radiology, University Hospital, LMU Munich, Munich, Germany.
Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany.
JHEP Rep. 2024 Aug 31;6(11):101199. doi: 10.1016/j.jhepr.2024.101199. eCollection 2024 Nov.
BACKGROUND & AIMS: MRI guidance offers better lesion targeting for microwave ablation of liver lesions with higher soft-tissue contrast, as well as the possibility of real-time thermometry. This study aims to evaluate the correlation of real-time MR thermometry-predicted lesion volume with the ablation zone in postprocedural first-day images.
This single-center retrospective analysis evaluated prospectively included patients who underwent MRI-guided microwave ablation with real-time thermometry between December 2020 and July 2023. All procedures were performed under general anesthesia on a 1.5 T MRI scanner. Real-time thermometry data were acquired using multi-slice gradient-echo echoplanar imaging sequences, and thermal dose maps (CEM43 of 240 min as a threshold) were created. The volume of tissue exposed to a lethal thermal dose in MR thermometry (thermal dose) was compared with the ablation zone volume in portal phase T1w MRI on the postprocedural first day using the Pearson correlation test, and visual quantitative assessment by radiologists was performed to evaluate the similarity of shapes and volumes.
Out of 30 patients with 33 lesions with thermometry images, six (18.1%) lesions were excluded because of artifacts limiting interpretation of thermal dose volume. Twenty-four patients with 27 lesions (20 male, age 63.1 ± 9.1 years) were evaluated for the volume correlation. The volume of thermal dose-predicted lesions and the postprocedural first-day ablation zones showed a strong correlation (R = 0.89, <0.001). Similarly, visual similarity of molecular resonance thermometry-predicted shape and the ablation zone shape was graded as perfect in 23 (85.1%) lesions.
Real-time thermal dose-predicted volumes show very good correlation with the ablation zone volumes in images obtained 1 day after the procedure, which could reduce the local recurrence rates with the possibility of re-ablating lesions within the same procedure.
Heat-based ablation is an established treatment for liver tumors; however, there is a considerable rate of incomplete treatment because of the lack of real-time visualization of the treated area during treatment. Our results show that MRI-guided ablation enables the visualization of the treatment area in real-time with high accuracy using a special technique of MR thermometry in patients with liver tumors.
磁共振成像（MRI）引导可为肝脏病变的微波消融提供更好的病灶靶向，其软组织对比度更高，还具备实时测温的可能性。本研究旨在评估实时MR测温预测的病灶体积与术后首日图像中消融区的相关性。
本单中心回顾性分析评估了2020年12月至2023年7月期间前瞻性纳入的接受MRI引导下实时测温微波消融的患者。所有手术均在全身麻醉下于1.5T MRI扫描仪上进行。使用多层梯度回波平面回波成像序列获取实时测温数据，并创建热剂量图（以240分钟的CEM43为阈值）。采用Pearson相关检验比较MR测温中暴露于致死热剂量的组织体积（热剂量）与术后首日门静脉期T1w MRI上的消融区体积，并由放射科医生进行视觉定量评估以评估形状和体积的相似性。
在30例有33个病灶且有测温图像的患者中，6个（18.1%）病灶因伪影限制了热剂量体积的解读而被排除。对24例有27个病灶（20例男性，年龄63.1±9.1岁）的患者进行了体积相关性评估。热剂量预测病灶的体积与术后首日消融区显示出强相关性（R = 0.89，<0.001）。同样，分子共振测温预测形状与消融区形状的视觉相似性在23个（85.1%）病灶中被评为完美。
实时热剂量预测的体积与术后1天获得的图像中的消融区体积显示出非常好的相关性，这有可能降低局部复发率，并有可能在同一手术中对病灶进行再次消融。
基于热的消融是治疗肝脏肿瘤的既定方法；然而，由于治疗期间缺乏对治疗区域的实时可视化，治疗不彻底的发生率相当高。我们的结果表明，MRI引导下的消融能够通过一种特殊的MR测温技术在肝脏肿瘤患者中实时、高精度地可视化治疗区域。
