At present, traditional modalities of neuroimaging, such as CT and MRI, is very limited in the diagnosis and severity estimation of diffuse axonal injury (DAI).OBJECTIVE:
To investigate the value of proton magnetic resonance spectroscopy (1HMRS) in the diagnosis and prognosis of DAI.DESIGN, TIME AND SETTING:
Prospective clinical controlled observation. The study was performed at the Department of Neurosurgery, and Department of Radiology, First Affiliated Hospital of Chongqing Medical University between October 2002 and September 2007.PARTICIPANTS:
A total of 63 subjects with traumatic brain injury were enrolled and divided into DAI group (n=27) and non-DAI group (n=36) according to the result of MRI. In addition, 20 healthy persons were served as control group.METHODS:
Demographic and clinical data were recorded on admission and neuroimaging examinations including fluid attenuated inversion recovery were carried on according to carefully designed procedures. In addition, 1HMRS was performed and the data were analyzed in combination with clinical condition.MAIN OUTCOME MEASURES:
The ratios of N-acetyl aspartate (NAA)/creatine (Cr) and creatine phosphate (Cr), Choline compound (Cho)/Cr, myoinositol (mlNs)/Cr, and glutamic acid (Glx)/Cr at genu and splenium of corpus callosum, and basal ganglia were quantified using 1HMRS.RESULTS:
Compared with control and non-DAI groups, DAI group had decreased NAA/Cr and increased Cho/Cr at genu and splenium of corpus callosum, and basal ganglia (P < 0.05-0.01), as well as increased mINs/Cr and Glx/Cr at genu and splenium of corpus callosum (P < 0.05). Non-DAI group also showed decreased NAA/Cr at splenium and increased Cho/Cr at genu of corpus callosum compared with control group (P < 0.01), but the change degree was less than DAI group. A positive correlation between Cho/Cr at genu of corpus callosum and the period of primary unconsciousness was identified in DAI group (r=0.824, P < 0.01).CONCLUSION:
The 1HMRS indexes at genu and splenium of corpus callosum, and basal ganglia could serve as effective indexes for the diagnosis of DAI. The Cho/Cr could well reflect histological changes following injury and act as sensitive index to predict clinical injury.