The Value Of Susceptibility Weighted Imaging In Traumatic Axonal Injury

Objective: To study the diagnostic value of Susceptibility Weighted Imaging (SWI) and routine MR sequence in traumatic axonal injury and to analyze the relationship between the number of traumatic axonal injury lesions detected on SWI and Glasgow Coma Scale (GCS) and to explore the relationship between the number of traumatic axonal injury lesions detected on SWI and Glasgow outcome scale (GOS).Materials and methods: Thirty patients confirmed traumatic axonal injury clinically were included in this study. There were 22 males, 8 females, with age from 2 to 74. GCS had been taken at admission. Thirty two channel phased-array coil of SIEMENS Verio 3.0T superconducting MRI machine was chose to scan the brain in routine MR sequences and SWI sequence. The size, morphous, distribution, signal and number of lesions in each sequence were analyzed and recorded. Paired t-test had been taken in detected lesions' number of SWI by SPSS17.0 software. The correlation between the number of detected lesions on SWI sequence and GCS was analyzed. After six months' therapy, the GOS were taken. The correlation between the number of detected lesions on SWI sequence and GOS was analyzed.Results:â‘ The appearance of lesions with traumatic axonal injury were nonspecific on routine MR sequences, showed high signal on T2WI and FLAIR. The signal on T1WI and DWI was various. It was insensitive in displaying microbleeding on routine MR sequence, while microbleeding showed low signal on Magnitude Image, SWI image and Min IP image, but high signal on Phase Image.â‘¡The number of lesions detected by FLAIR was 183(most among the routine MR sequence), was 227 by DWI and was 1252 by SWI. Most lesions were located at frontal lobes. There were 89 lesions in frontal lobes on FLAIR sequence, 107 on DWI sequence and 468 on SWI sequence. Paired t-test had been taken between the lesions detected on SWI and FLAIR, and the result was t=-4.652,P<0.001. Paired t-test had also been taken between the lesions detected on SWI and DWI, and the result was t=-4.779,P<0.001.â‘¢The most number of lesions was detected by SWI among all sequences. Rank correlation had been taken to analyze the relationship of GCS and the number of lesions detected by SWI. The result was r=-0.670,P<0.001. After six months' therapy, the same method had been used to analyze the relationship of GOS and the number of lesions detected by SWI. The result was r =-0.654,P<0.001.Conclusion: The diagnostic value of SWI was the highest in finding microbleeding of traumatic axonal injury among all MR sequences. The SWI sequence could be used to evaluate the extent and prognosis of traumatic axonal injury.