Scheid Rainer, Ott Derek V, Roth Henrik, Schroeter Matthias L, von Cramon D Yves
Day Clinic of Cognitive Neurology, University of Leipzig, Leipzig, Germany.
J Neurotrauma. 2007 Dec;24(12):1811-6. doi: 10.1089/neu.2007.0382.
Traumatic microbleeds (TMBs) can be regarded as a radiological marker of diffuse axonal injury (DAI). We sought to investigate the impact of the field strengths on the depiction of TMBs by T2*-weighted gradient echo magnetic resonance imaging (MRI). By the use of comparative MRI of 14 patients (age range, 22-62 years) on 1.5- and a 3 T (Tesla) systems at a median time interval of 61 months after traumatic brain injury (TBI), we found 239 (range 0.5-48.5, median 7.5) TMBs at 1.5 T, and 470 (range 2-118, median 18.5) TMBs at 3 T, respectively (p=0.001). However, in all but one patients MRI at 1.5 T also clearly showed TMBs. A significant negative correlation between the number of TMBs and the time interval TBI-MRI was observed, which was weaker for the imaging at 3 T (r(s)=-0.798; p=0.001; and r(s)=-0.649; p=0.012, respectively). In conclusion, T2*-weighted gradient-echo MRI at 3 T is superior as compared to MRI at 1.5 T for the detection of TMBs. Nevertheless, in clinical practice, MRI at 1.5 T seems to be sufficient for this purpose. MRI at 3 T may be appropriate if there is a strong clinical suspicion of DAI, despite unremarkable routine MRI, and possibly also if evidence of DAI is sought after a long interval from trauma.
创伤性微出血（TMBs）可被视为弥漫性轴索损伤（DAI）的一种影像学标志物。我们试图研究场强对T2加权梯度回波磁共振成像（MRI）显示TMBs的影响。通过对14例患者（年龄范围22 - 62岁）在创伤性脑损伤（TBI）后61个月的中位时间间隔，分别在1.5 T和3 T（特斯拉）系统上进行对比MRI检查，我们发现在1.5 T时发现239个（范围0.5 - 48.5，中位值7.5）TMBs，在3 T时发现470个（范围2 - 118，中位值18.5）TMBs（p = 0.001）。然而，除1例患者外，其余所有患者在1.5 T时的MRI也清晰显示了TMBs。观察到TMBs数量与TBI - MRI时间间隔之间存在显著负相关，3 T成像时这种相关性较弱（斯皮尔曼相关系数分别为r(s)= - 0.798；p = 0.001；以及r(s)= - 0.649；p = 0.012）。总之，与1.5 T的MRI相比，3 T的T2加权梯度回波MRI在检测TMBs方面更具优势。尽管如此，在临床实践中，1.5 T的MRI似乎足以满足此目的。如果临床高度怀疑DAI，尽管常规MRI无异常表现，或者在创伤后较长时间间隔后寻求DAI证据时，3 T的MRI可能是合适的。
