Comparative magnetic resonance imaging at 1.5 and 3 Tesla for the evaluation of traumatic microbleeds.
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.
Scheid
Rainer
R
Day Clinic of Cognitive Neurology, University of Leipzig, Leipzig, Germany. scheid@cbs.mpg.de
Ott
Derek V
DV
Roth
Henrik
H
Schroeter
Matthias L
ML
von Cramon
D Yves
DY
D000328:Adult; D020202:Cerebral Hemorrhage, Traumatic / Q000175:diagnosis*; D020833:Diffuse Axonal Injury / Q000175:diagnosis*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged