颞叶癫痫在3T与7TMRI上的影像对比及与病理对照分析

目的 比较颞叶癫痫致痫灶3 T和7 T MR成像差异，并与病理结果对照分析，以确定7 T MRI在呈现、检测病变以及精确定位诊断中的意义。方法 共纳入2014年1月—2017年12月期间确诊的34例颞叶癫痫病人[男18例，女16例；平均年龄(27±8)岁]及5名正常对照（男3名，女2名；平均年龄27岁），均行术前3 T和7 T MR扫描，全部病人均获术后病理结果。由2名高年资放射科医师对术前影像和病理结果进行对照分析，并对病理为海马硬化（HS）者的海马内部结构进行评分。采用配对t检验对3 T和7 T MRI上双侧海马内部结构评分进行比较。结果 病理诊断为HS者24例，其中20例在3 T及7 T MRI上诊断明确，4例MRI术前诊断欠明确。3 T 和7 T MRI上，患侧海马内部结构评分均低于正常侧（P<0.001）。7 T MRI上海马内部结构评分均高于3 T MRI（P<0.05）。局灶性皮质发育不良（FCD）6例（FCD Ia 2例、FCDIIIa 3例、FCDIIId 1例）。颞叶FCD Ia在3 T 及7 T MRI上均未发现，FCDIIIa及FCDIIId海马区病灶在3 T MRI及7 T MRI上均清楚显示。海马、颞叶占位4例（节细胞胶质瘤2例，脑膜瘤1例，左侧杏仁体部分区域胶质细胞增生1例）在3 T和7 T MRI均清楚显示。对5例正常对照脑部结构的显示，7 T MRI优于3 T MRI。结论 典型病灶在3 T及7 T MRI均可发现，7 T MRI对海马内部精细结构的显示优于3T MRI；不典型病灶7 T MRI能够更好地显示解剖精细结构，但有些病灶如FCD Ia提高场强后仍无法分辨。

Qualitative comparison between 3 T and 7 T MRI using pathological results as standard in patients with temporal lobe epilepsy

Objective To determine if 7 T outperform 3 T MRI in presenting and detecting lesions by comparing the differences of 3 T and 7 T MRI in patients with temporal lobe epilepsy with pathological results. Methods From January 2014 to December 2017, we performed 3T and 7TMR scans on 34 patients with temporal lobe epilepsy (male 18, female 16; mean age 27±8 years) and 5 normal controls (male 3, female 2; mean age 27±0 years). All patients underwent the surgery of lesion resection and had pathological analysis. MRI qualitative analysis was based on different pathological results by two experienced neuroradiologists. Semi-quantitative assessment of the bilateral hippocampal internal architecture (HIA) were acquire on patients diagnosed with hippocampal sclerosis (HS) pathologically. Differences in HIA scores between epileptogenic and non-epileptogenic hippocampi on 3 T and 7 T MRI were evaluated by paired t test. Results Among the 34 patients, 24 cases were diagnosed with hippocampal sclerosis pathologically, of which 20 cases presented typical hippocampal sclerosis on both 3T and 7TMRI, and 4 cases are certain neither 3T nor 7TMRI. Among these patients, HIA scores of the epileptogenic hippocampi were lower than that of contralateral hippocampi (P<0.001) in either 3TMRI or 7TMRI. Difference existed in the bilateral hippocampi (P<0.05), in which HIA scores acquired from 7TMRI were higher than those on 3T. 6 cases were diagnosed with focal cortical dysplasia (2 cases of FCD Ia, 3 cases of FCDIIIa, 1 case of FCDIIId). Hippocampal lesions of FCDIIIa and FCDIIId were presented on both 3T and 7TMRI, but all FCD Ia lesions were not distinguished on 3T and 7TMRI. 4 cases were diagnosed with mass in temporal lobe (2 cases of gangliogliomas, 1 case of meningioma, 1 case of leftamygdala glial cell hyperplasia), which were all clearly appeared on 3T and 7TMRI. In the 5 controls, brain structure on 7T was more clearly presented compared with the 3TMRI. Conclusion The typical lesions can be clearly presented on both 3 T and 7 T MRI. 7TMRI was relatively superior to 3TMRI in displaying the subtle hippocampal internal architecture. For atypical lesions, 7 T MRI can better present the subtle structure, but some lesions such as FCDIa still can not be distinguished.