MRI能较敏感地检测多数中枢神经系统疾病病变,了解病变的部位及范围,但对一些微观病变或疾病早期病理变化,常规MRI不能提供确切的评价。磁化传递成像(magnetization transfer imaging,MTI)是一种对大分子结构微观神经病理变化比较敏感的...MRI能较敏感地检测多数中枢神经系统疾病病变,了解病变的部位及范围,但对一些微观病变或疾病早期病理变化,常规MRI不能提供确切的评价。磁化传递成像(magnetization transfer imaging,MTI)是一种对大分子结构微观神经病理变化比较敏感的MRI技术,通过施加偏共振饱和脉冲序列选择性地抑制大分子物质信号而增加图像对比、获得更多的组织结构信息。大量研究表明MTI能检出常规MRI检查阴性患者的脑灰、白质变化,如多发性硬化。近年来,该技术在精神疾病的研究逐渐增多,为更好地理解精神疾病的病理生理机制提供了新的补充信息,本文综述MTI在精神疾病中的应用现状及临床意义。展开更多
The severity of tissue changes associated with incidental white matter hyperintensities (WMH) in the elderly cannot be sufficiently determined by conventional MRI. We, therefore, performed a regional analysis of the m...The severity of tissue changes associated with incidental white matter hyperintensities (WMH) in the elderly cannot be sufficiently determined by conventional MRI. We, therefore, performed a regional analysis of the magnetization transfer ratio (MTR) maps obtained on a 1.5 T scanner from 198 neurologically asymptomatic participants of the Austrian Stroke Prevention Study (mean age 70, age range 52-87 years) in regard to WMH and predefined areas of normal appearing brain tissue. Fluid attenuated inversion recovery MRI was used to grade lesion severity and for lesion volume measurements. The MTR of WMH was always significantly lower than that of normal appearing white matter (NAWM) with an overall relative reduction of 10%and decreased significantly with increasing scores of WMH severity (P = 0.02) and WMH volume (r = -0.24, P = 0.0016). NAWM MTR was not different between subjects with very few and extensive WMH and the WMH volume was associated with NAWM MTR of the frontal lobes only. Concerning a possible impact on cerebral functioning the MTR of the frontal NAWM was significantly associated with fine motor dexterity (P = 0.04) but not with cognitive performance. A significant decline of the MTR with aging was seen in both NAWM and cortex but not in WMH. We conclude that MTR measurements can serve to quantify WMH associated tissue damage. It is predominantly focal, relatively mild, increases with lesion size and may have remote effects on the frontal white matter.展开更多
文摘MRI能较敏感地检测多数中枢神经系统疾病病变,了解病变的部位及范围,但对一些微观病变或疾病早期病理变化,常规MRI不能提供确切的评价。磁化传递成像(magnetization transfer imaging,MTI)是一种对大分子结构微观神经病理变化比较敏感的MRI技术,通过施加偏共振饱和脉冲序列选择性地抑制大分子物质信号而增加图像对比、获得更多的组织结构信息。大量研究表明MTI能检出常规MRI检查阴性患者的脑灰、白质变化,如多发性硬化。近年来,该技术在精神疾病的研究逐渐增多,为更好地理解精神疾病的病理生理机制提供了新的补充信息,本文综述MTI在精神疾病中的应用现状及临床意义。
文摘目的 探讨泪腺磁化传递成像(magnetization transfer imaging, MTI)定量参数在甲状腺相关性眼病(thyroid-associated ophthalmopathy, TAO)临床活动性分期中的价值。材料与方法 前瞻性纳入2020年9月至2022年1月在南京医科大学第一附属医院临床诊断为TAO的49名患者,依据临床活动性评分(Clinical Active Score, CAS)将受试者分为活动期组(≥3分,29例)和非活动期组(<3分,20例)。所有受试者均行眼眶常规MRI序列及冠状位MTI扫描,并测量泪腺磁化传递率(magnetization transfer ratio, MTR)及脂肪抑制T2WI序列上泪腺与同侧颞肌信号强度比(signal intensity ratio, SIR)。采用Mann-Whitney U检验比较MRI定量参数的组间差异。采用Spearman相关分析评估MRI定量参数与CAS的相关性。采用受试者工作特征曲线分析MTR、SIR及两者联合判断TAO临床活动性的效能,并采用DeLong检验比较曲线下面积(area under the curve, AUC)。结果 活动期组泪腺MTR低于非活动期组,泪腺SIR高于非活动期组,差异均有统计学意义(P<0.001)。MTR与CAS呈低度负相关(r=-0.427,P<0.001),SIR与CAS呈弱正相关(r=0.252,P=0.012)。联合泪腺MTR和SIR判断TAO临床活动性效能最优(AUC=0.809,敏感度62.5%,特异度93.1%),高于单独应用SIR,差异有统计学意义(Z=2.35,P=0.019)。结论 泪腺MTI定量参数在判断TAO临床活动性中具有可行性,可以作为常规序列的补充手段,以提高对TAO临床活动性分期的评估能力。
文摘The severity of tissue changes associated with incidental white matter hyperintensities (WMH) in the elderly cannot be sufficiently determined by conventional MRI. We, therefore, performed a regional analysis of the magnetization transfer ratio (MTR) maps obtained on a 1.5 T scanner from 198 neurologically asymptomatic participants of the Austrian Stroke Prevention Study (mean age 70, age range 52-87 years) in regard to WMH and predefined areas of normal appearing brain tissue. Fluid attenuated inversion recovery MRI was used to grade lesion severity and for lesion volume measurements. The MTR of WMH was always significantly lower than that of normal appearing white matter (NAWM) with an overall relative reduction of 10%and decreased significantly with increasing scores of WMH severity (P = 0.02) and WMH volume (r = -0.24, P = 0.0016). NAWM MTR was not different between subjects with very few and extensive WMH and the WMH volume was associated with NAWM MTR of the frontal lobes only. Concerning a possible impact on cerebral functioning the MTR of the frontal NAWM was significantly associated with fine motor dexterity (P = 0.04) but not with cognitive performance. A significant decline of the MTR with aging was seen in both NAWM and cortex but not in WMH. We conclude that MTR measurements can serve to quantify WMH associated tissue damage. It is predominantly focal, relatively mild, increases with lesion size and may have remote effects on the frontal white matter.
