鼻咽癌放射治疗后颞叶损伤的质子磁共振波谱表现

Findings of 1H magnetic resonance spectroscopy for radiation induced-temporal lobe necrosis in nasopharyngeal carcinoma

目的 初步报道鼻咽癌放射治疗后颞叶损伤的1HMRS表现 ,以期对临床诊断有所帮助 ,并初步探讨其临床意义。方法 对 13例鼻咽癌放射治疗后颞叶损伤病例行MRS检查。所有病例均在复旦大学附属华山医院检查 ,使用GESingaHorizont 1.5T超导型磁共振成像机 ,采用头颅正交线圈。所有病例均先进行MRI检查 ,再进行1HMRS检查 ,1HMRS采用点分辨波谱分析法及化学位移选择饱和水抑制法采集信号。成像参数为TR2 0 0 0ms ,TE14 4ms ;成像时间为 348s ;体素 (voxel)大小 2cm× 2cm× 2cm ;取样时将体素置于病灶的实质部分。并行对侧相应颞叶脑组织HMRS作对照 (双侧颞叶损伤除外 )。结果 首程放射距1HMRS检查的中位时间为 4 2个月 ( 32～ 172个月 )。 13例中双侧颞叶病灶 5例 ,共发现 18个病灶。 5例双侧颞叶损伤未进行正常脑组织14 HMRS的对照检查 ,1例双侧颞叶损伤仅进行了 1侧病灶检查 ,因此 13例共进行了 17个病灶区和 8个正常脑组织HMRS检查。HMRS表现为病灶侧NAA/Cr均值为 1.33± 0 .2 8,而对照脑组织的NAA/Cr均值为 1.78± 0 .34,二者差异有显著性意义 (t=3.2 2 ,P =0 .0 0 5 )。 3个病灶出现NAA、Cho、Cr峰消失 (其中 2个病灶伴Lip峰 )。8例有对照的颞叶损伤中 6例病灶侧Cho/Cr比值低于对照侧。 4个病灶出现Lip?

Objective To observe the findings of 1H magnetic resonance spectroscopy ( 1H MRS) and explore its value for diagnosis of radiation induced-temporal lobe necrosis in nasopharyngeal carcinoma (NPC). Methods Thirteen patients with definite clinical diagnosis of radiation induced temporal lobe necrosis in NPC underwent 1H MRS. All 1H MRS examinations were performed on a Singa Horizont 1.5 T whole body MR system with point resolved spectroscopy (PRESS) and chemical-shift selective saturation (CHESS) (TR=2000?ms,TE=144 ?ms). The voxel (2?cm × 2?cm × 2?cm) was positioned in both of the lesion and the contralateral side of the temporal lobe as the control (except for bilateral lesions). 2THZ]Results The interval between radiation and the examination ranged from 32 to 172 months ( median, 42 months). Eighteen lesions were observed in 13 patients (5 patients with bilateral lesions). 1H MRS was performed on 17 lesions and 8 control temporal lobes. The mean values of NAA/ Cr in the lesions and the control temporal lobes were 1.33±0.28、1.78±0.34 respectively(t=3.22, P=0.005). Three lesions showed NAA、Cho and Cr peak absent (2 lesions with Lip peak ). Among 8 patients with the control temporal lobes 1H MRS examined, Cho/Cr decreased in 6 patients (75%). Four lesions showed Lip , Lac and MI, respectively. Conclusions The radiation-induced temporal lobe necrosis shows abnormal features on 1H MRS. Significant decrease of NAA/ Cr as well as Cho/Cr are observed in most patients. 1H MRS may play a role in the diagnosis of radiation induced temporal lobe necrosis.