Wintermark M, Druzgal J, Huss D S, Khaled M A, Monteith S, Raghavan P, Huerta T, Schweickert L C, Burkholder B, Loomba J J, Zadicario E, Qiao Y, Shah B, Snell J, Eames M, Frysinger R, Kassell N, Elias W J
From the Departments of Radiology, Neuroradiology Division (M.W., J.D., P.R., T.H., L.C.S., B.B., Y.Q.)
From the Departments of Radiology, Neuroradiology Division (M.W., J.D., P.R., T.H., L.C.S., B.B., Y.Q.).
AJNR Am J Neuroradiol. 2014 May;35(5):891-6. doi: 10.3174/ajnr.A3808. Epub 2013 Dec 26.
MR imaging-guided focused sonography surgery is a new stereotactic technique that uses high-intensity focused sonography to heat and ablate tissue. The goal of this study was to describe MR imaging findings pre- and post-ventralis intermedius nucleus lesioning by MR imaging-guided focused sonography as a treatment for essential tremor and to determine whether there was an association between these imaging features and the clinical response to MR imaging-guided focused sonography.
Fifteen patients with medication-refractory essential tremor prospectively gave consent; were enrolled in a single-site, FDA-approved pilot clinical trial; and were treated with transcranial MR imaging-guided focused sonography. MR imaging studies were obtained on a 3T scanner before the procedure and 24 hours, 1 week, 1 month, and 3 months following the procedure.
On T2-weighted imaging, 3 time-dependent concentric zones were seen at the site of the focal spot. The inner 2 zones showed reduced ADC values at 24 hours in all patients except one. Diffusion had pseudonormalized by 1 month in all patients, when the cavity collapsed. Very mild postcontrast enhancement was seen at 24 hours and again at 1 month after MR imaging-guided focused sonography. The total lesion size and clinical response evolved inversely compared with each other (coefficient of correlation = 0.29, P value = .02).
MR imaging-guided focused sonography can accurately ablate a precisely delineated target, with typical imaging findings seen in the days, weeks, and months following the treatment. Tremor control was optimal early when the lesion size and perilesional edema were maximal and was less later when the perilesional edema had resolved.
磁共振成像引导聚焦超声手术是一种新型立体定向技术，利用高强度聚焦超声加热并消融组织。本研究的目的是描述磁共振成像引导聚焦超声损毁腹中间核治疗特发性震颤前后的磁共振成像表现，并确定这些成像特征与磁共振成像引导聚焦超声治疗临床反应之间是否存在关联。
15例药物难治性特发性震颤患者前瞻性地给予同意；参加了一项单中心、美国食品药品监督管理局批准的试点临床试验；并接受了经颅磁共振成像引导聚焦超声治疗。在手术前以及手术后24小时、1周、1个月和3个月，使用3T扫描仪进行磁共振成像研究。
在T2加权成像上，在焦点部位可见3个随时间变化的同心区。除1例患者外，所有患者在24小时时内2个区的表观扩散系数值降低。在1个月时，当空洞塌陷时，所有患者的扩散已假性正常化。在磁共振成像引导聚焦超声治疗后24小时及1个月时可见非常轻微的增强后强化。总病灶大小与临床反应呈相反变化（相关系数=0.29，P值=0.02）。
磁共振成像引导聚焦超声可以准确消融精确划定的靶点，在治疗后的数天、数周和数月内可见典型的成像表现。当病灶大小和病灶周围水肿最大时，震颤控制在早期最佳，而在病灶周围水肿消退后则较差。
