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Purpose To explore the application value of diffusion kurtosis imaging (DKI) in assessing brain injury in different clinical stages caused by carbon monoxide (CO) poisoning. Materials and Methods MR plain scan, diffusion weighted imaging (DWI) and DKI scans were performed in 26 patients with acute CO poisoning, 17 patients with delayed neuropsychologic sequelae (DNS), 15 patients with chronic phase, and 21 healthy volunteers (control group). The DKI parameter values in regions of interest among the four groups were compared, and the correlation between the values of each parameter and DWI apparent diffusion coefficient (ADC) value was analyzed. Results ①The mean kurtosis (MK) values in the area of pallidum in acute phase, DNS phase, and chronic phase were 1.51±0.15, 1.07±0.11 and 0.59±0.11, respectively; among which the MK value in acute phase was significantly higher than that in the control group (1.06±0.06, P<0.05), and the chronic phase was significantly lower than the DNS phase and the control group (P<0.05); compared with the control group, the MK in centrum semiovale and subcallosal zone was relatively higher in acute phase and DNS phase, lower in chronic phase, both showing the most significant increase in DNS phase (P<0.05). ②In each region of interest, the MK value and mean diffusivity (MD) all showed an increase after decrease. Among them, MD values in the area of pallidum in acute phase were significantly lower than those in DNS and control group (0.74±0.11 vs. 0.85±0.07 and 0.98±0.12, P<0.05), and the centrum semiovale and callosum were the smallest in DNS phase (0.67±0.09 and 0.80±0.05, respectively), significantly lower than that in the control group (P<0.05). ③The fractional anisotropy (FA) values of all regions of interest showed a progressive decrease in different clinical stages, in which pallidum and centrum semiovale were the lowest in chronic phase (0.19±0.04 and 0.22±0.03, respectively), significantly lower than those in DNS phase and the control group (P<0.05). ④There was a positive correlation between MD values and ADC values in different clinical stages of CO poisoning in each region of interest (P<0.01). Conclusion DKI can quantitatively evaluate the changes of brain gray matter microarchitecture after CO poisoning, which is helpful to understand the characteristics of brain injury in different clinical stages caused by CO poisoning from the microscopic level.
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Objective To explore the value of intravoxel incoherent motion DWI (IVIM-DWI) combined with single-voxel MRS in distinguishing osteoporotic fractures from metastatic vertebral compression fractures.Methods Totally 70 patients with vertebral compression fractures,who underwent CT scanner were enrolled.The patients were divided into osteoporotic group or metastatic group based on pathological results or clinical follow-up.All patients underwent conventional sagittal T1W,T2W,STIR,IVIM-DWI and single-voxel MRS scanning.Relative peak areas of the signal of water at 4.7 ppm and lipid at 1.3 ppm were determined.IVIM-DWI parameters (diffusion coefficient [D],pseudo diffusion [D*],perfusion fraction [f]) and MRS parameters (lipid water ratio [LWR],fat fraction [FF]) were also recorded.The diagnostic performance of MRS,IVIM-DWI,as well as MRS combined with IVIM-DWI in distinguishing osteoporotic fractures from metastatic vertebral compression fractures were evaluated by using ROC curve,and the area under curve (AUC) was calculated.Results The f,D and FF in metastatic group were significantly lower than those in osteoporotic group,while D* in metastatic group was significantly higher than that in osteoporotic group (all P＜0.05).The sensitivity,specificity and accuracy in differentiating osteoporotic fractures from metastatic vertebral compression fractures was 87.50％ (28/32),57.89 (22/38) and 71.43％ (50/70) of MRS,78.13％ (25/32),89.47％ (34/38) and 84.28％ (59/70) of IVIM-DWI,90.63％ (29/32),97.37％ (37/38) and 94.29％ (66/70) of MRS combining with IVIM-DWI,respectively.AUC of MRS,IVIM-DWI,as well as MRS combined with IVIM-DWI was 0.73,0.88 and 0.94 (all P ＜0.05),respectively.Conclusion Combination of IVIM-DWI and MRS can improve the diagnostic efficiency of differentiating osteoporotic fractures from metastatic vertebral compression fractures.
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Purpose To quantitatively evaluate the severity of brain damage in the acute phase of CO poisoning using intravoxel incoherent motion imaging.Materials and Methods MRI scans were performed in 26 patients with CO intoxication of acute stage and 18 healthy controls with matched age and gender.The difference of D value,D* value and f value in different ROIs between the poisoning and the control groups were compared,and the best cut-off values were determined.The correlation between the consciousness state and the D value as well as f value in the vulnerable area of the brain (globus pallidus) was analyzed.Results Compared with control group,the D and F value of the poisoning group were decreased in multiple ROIs,of which statistical significance was observed in the f values in the centrum semiovale,globus pallidus and thalamus,and the D values in the centrum semiovale,lateral ventricle,globus pallidus and corpus callosum splenium (P＜0.05).The best cut-off value,sensitivity and specificity were as follows:fcs=51％,77％,73％;fga=61％,77％,83％;ft=80％,85％,64％;D,=0.69×10-3 mm2/s,85％,83％;Dlv=0.65× 10-3 mm2/s,73％,89％;Dga=0.68× 10-3 mm2/s,62％,83％;Dccs=0.70× 10-3mm2/s,81％,89％.The disturbance of consciousness was positively correlated with decrease of D value and f value (rD=0.828,rf=0.745,P＜0.05).Conclusion The D and f values of intravoxel incoherent motion imaging can quantitatively evaluate the brain damage severity in acute CO poisoning.
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Objective To study the method and ability of multi-slice CT isotropic scan and post-processing in displaying the anatomy of cervical vertebrae.Methods The normal cervical spines in 53 cases were scanned with isotropic parameters using 16-slice-helical CT.All the images were post-processed with the methods of MPR,MIP,SSD and VRT and each other were compared between them,then the best one was selected to compare with axial CT images and plain films.The abilities in displaying inter-vertebrae disc,spinal canal longtitude,vertebrae body,vertebral arch,zygapophyseal joint and inter-vertebrae foramen were compared among the 3D reconstruction,direct CT scan and X-ray plain film including post-anterior,lateral,left-anterior oblique and right-anterior position project.Results The quality of isotropic post-processing images had no remarkable differences with that of direct CT scan in showing inter-vertebrae disc,but it was better than X-ray plain film and conventional CT scan mode in showing other structures.Conclusion The multi-slice helical isotropic CT scan and post-processing images are of great value in the study of cervical spine.