RESUMO
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.
RESUMO
Objective To reconstruct the three-dimensional images of normal liver using 256-slice intelligent CT (iCT)and to measure the volume of liver and its segments.Methods 48 healthy adults underwent abdominal contrast enhancement iCT,and the images in portal venous phase were transmitted to a workstation (EBW4.5)to obtain the three-dimensional images of the liver.The total liver volume was measured,and a scatter plot was gotten between body surface area and liver volume.According to the Couinaud classification of hepatic segment ofⅠ-Ⅷ,the volume of each segment was also measured.Results The mean total liver volume in 48 adults was (1 343.2±238.3)mL,which was positively correlated with body surface area with a correlation coefficient of 0.87 and a regression equation of LV(mL)=763.0×BSA-28.6.The volume of SegmentⅠ-Ⅷ was(24.5±4.3)mL,(148.6±31.6)mL,(110.4±24.9)mL, (222.3±43.0)mL,(212.8±36.5)mL,(186.7±34.7)mL,(164.3±30.8)mL and (273.4±56.1)mL,and their percentage was (1.8±0.2)%,(11.0±1.1)%,(8.2±1.1)%,(16.6±1.4)%,(15.9±1.0)%,(13.0±1.0)%,(12.2±0.7)% and (20.3±1.5)% respec-tively.Conclusion The three-dimensional images of liver and hepatic segments can be well reconstructed by 256 slice iCT.