ABSTRACT
Objective To evaluate the clinical value of susceptibility?weighted imaging(SWI) in detecting intramedullary hemorrhage of traumatic acute spinal cord injury. Methods From October 2012 to December 2014, 37 TSCI (traumatic spinal cord injuries) patients undergone the MRI scans including routine MRI and SWI were enrolled. Further according to ASIA classification standard, all patients were evaluated as ASIA A (n=4), ASIA B (n=4), ASIA C (n=19) and ASIA D (n=10). Referring to axial T2WI images at the same slice, the manifestations of hemorrhage in amplitude image, phase image and SWI were evaluated. At the slice with maximal size of hemorrhage area and its neighboring slices, the hemorrhage regions were manually drawn; and the total area was automatically calculated. The number of hemorrhage lesions was defined as the number of hemorrhage lesions at single slice × slice number. One?way ANOVA was used to compare the differences among different grading ASIA in terms of hemorrhage area and number. Meanwhile, the relations between hemorrhage area and ASIA grade; hemorrhage number and ASIA grade were evaluated by Spearman rank correlation. Results The hemorrhage was detected by SWI in 15 patients, including 4 ASIA A, 4 ASIA B, 7 ASIA C. Hemorrhage represents as isointense in T1WI and a slightly low signal intensity or isointense in the center companied by high intensity at circus in T2WI. In magnitude image and SWI hemorrhage appears as low signal intensity and low signal intensity in the center companied by high intensity at circus in phase image. In detecting the hemorrhage, SWI (98 lesions were detected) was 5.4 times of T2WI (19 lesion were detected). As for the number of hemorrhage, significant differences were found among ASIA grading A, B and C (grading A:22.5 ± 1.3, grading B:19.5 ± 1.3, grading C:4.0 ± 1.1;F=38.720, P<0.01); Further the pairwise comparison showed statistical significance (P<0.05); besides, the number of hemorrhage lesions closely related with the ASIA grade (r=0.864, P<0.01). For the hemorrhage area, the calculated results of grading ASIA A, B and C were (23.5 ± 0.6), (21.8 ± 1.9), (3.9 ± 0.7) mm2, respectively; there were significant differences among the different ASIA grades (F=29.987, P<0.001);furthermore the hemorrhage area also showed closely relation with the ASIA grade (r=0.778, P<0.01). Conclusions SWI is more sensitive in detecting the hemorrhage in traumatic acute spinal cord injury. The more number and area of bleeding area suggest the more severe of the damage level.
ABSTRACT
Objective To investigate MRI features of heat stroke (HS) and 1H-MRS in monitoring clinical outcome.Methods Six cases(4 males,2 females) of HS patients,aged 43-75 years old were retrospectively studied.The patients were divided into 4 severe cases (2 cases with coma for 4 hours,2 patients with persistent coma) and 2 moderate cases according to initial Glasgow coma scale (GCS) at the time of hospital admission.All patients underwent T1WI,T2WI,FLAIR,DWI,SWI,multi voxel 1H-MRS scans and the ratios of NAA/Cr,Cho/Cr,and NAA/Cho were calculated.One case of severe coma died on the next day.Follow-up imaging and brain 1H-MRS were performed on other 5 patients on the 7th and 15th day after the first examination.The imaging results were compared with clinical outcome.Results MRI features of HS for severe coma patients were iso-intensity on T1WI,hyper-intensity on T2WI,FLAIR and DWI,heterogeneous signal intensity on ADC.The infratentorial lesions distributed in the cerebellum,dentate nucleus and cerebellar arm (3 cases),and the supratentorial lesions distributed in the parahippocampal gyrus (2 cases),parietal lobe (2 cases),and temporal lobe (1 cases).The lesions could be multiple,and the cerebellum and the parahippocampal gyrus were most common involved.SWI showed focal hemorrhage in 2 cases,which located in the brainstem and parietal lobe.No obvious MRI abnormality was found in 2 cases of moderate coma patients.The ratios of NAA/Cr,Cho/Cr,and NAA/Cho for severe coma patients were 0.67 ±0.09,0.94 ±0.16 and 0.70±0.12,respectively,which for moderate coma patients were 0.87±0.12,0.95±0.13,and 0.94±0.08,respectively.The NAA/Cr and NAA/Cho ratios decreased and Cho/Cr mild decreased in the severe coma patients when compared with the moderate coma patients.One patient with persistent coma had expanded lesions on follow-up study.NAA/Cr,NAA/Cho and Cho/Cr were 0.63± 0.07,0.67 ±0.10,and 0.96 ±0.05,respectively.Two cases had smaller lesions on follow-up study with NAA/Cr and NAA/Cho ratio increased,which were 1.02±0.13 and 0.96±0.11,respectively.GCS was turned to 14.NAA/Cr and NAA/Cho for moderate coma patients were 1.17±0.10 and 1.21 ±0.07,respectively.Conclusions Severe HS patients present with cerebral edema and hemorrhage.1H-MRS can be an important index for monitoring the severity of HS.The longer the duration of coma,the worse prognosis may happen.