多次使用钆对比剂后MRI平扫小脑齿状核T1WI信号增高的初步研究

Increased signal intensity in the dentate nucleus on unenhanced T1-weighted MR images after multiple gadolinium-based contrast material administrations: a preliminary study

目的研究多次使用线性钆对比剂后,小脑齿状核、脑桥和脑脊液在MR平扫T1WI上的信号强度的变化。方法回顾性分析2017年1月至12月49例连续进行至少4次MR增强检查的患者的临床及影像学资料(多次增强检查前后均进行了颅脑MR平扫检查)。在多次增强前后T1WI上测量齿状核、脑桥及脑脊液的平均信号强度,计算齿状核/脑桥、齿状核/脑脊液的信号强度比值。采用配对样本t检验分析同一患者多次增强检查前后T1WI上齿状核/脑桥、齿状核/脑脊液信号强度比之间是否存在差异。采用线性回归分析方法,分析多种临床因素与多次增强前后齿状核/脑桥、齿状核/脑脊液信号强度变化是否相关。结果多次增强后齿状核/脑桥、齿状核/脑脊液的信号强度比均大于增强前的信号强度比,差异具有统计学意义。多次增强前、后齿状核/脑桥、齿状核/脑脊液信号强度比分别为0.98±0.62、1.05±0.54,3.89±0.94、4.97±1.61(t=-8.494、-4.526,P值均<0.001)。接受线性钆对比剂注射次数与信号强度比之间存在正相关(齿状核/脑桥回归系数=0.006,P=0.003,齿状核/脑脊液回归系数=0.144,P=0.009),与其他临床因素无关(P值均>0.05)。结论多次接受钆对比剂注射的患者,T1WI齿状核信号增高,且与增强检查次数呈正相关。

Objective To compare changes in signal intensity (SI) of the dentate nucleus (DN), pons and cerebrospinal fluid (CSF) on unenhanced T1-weighted magnetic resonance imaging (MRI) scans after multiple administrations of the linear gadolinium-based contrast agent. Methods Clinical and imaging data of forty-nine patients who underwent at least 4 consecutive enhanced MRI examinations were analyzed retrospectively (unenhanced T1-weighted MRI scans were performed before and after consecutive enhanced MRI examinations). The mean SI of DN, pons and CSF were measured on unenhanced T1-weighted images. The SI ratio of DN to pons was calculated by dividing the SI in the DN by that in the pons, and so was The DN to CSF SI ratio. The difference of SI ratio of DN-to-pons and DN-to-CSF in the same patient before and after repeated contrast-enhanced T1WI were analyzed by paired-samples t tests. Linear regression analysis was used to analyze whether the SI ratios of DN-to-pons, DN-to-CSF were correlated with any clinical factor. Results The SI ratios of DN-to-pons and DN-to-CSF after multiple contrast administrations were higher than those before enhancement, and the differences were statistically significant. The SI ratios of DN-to-pons and DN-to-CSF before and after repeated contrast enhancement were 0.98±0.62,1.05±0.54;3.89±0.94,4.97±1.61 (t=-8.494,-4.526,P<0.001) . The SI ratio differences showed a significant positive correlation with the number of previous gadolinium-based contrast material administrations (pons:b=0.006,P=0.003,CSF:b=0.144,P=0.009). There was no correlation with any other clinical factors(P>0.05).