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Objective To explore the 18F-FDG PET/CT features of sacral insufficiency fracture.Methods 18 F-FDG PET/CT imaging and clinical data of 8 patients with sacral insufficiency fracture were retrospectively analyzed.Results All 8 patients had different degrees of radioactivity uptake in sacra with the maximum standardized uptake value (SUVmax)from 2.7 to 7.2.Four patients had lesions in their left sacra,2 in the bilateral sacral wings and sacral promontories,1 in the bilateral sacral wings,and 1 in the left sacral wing and sacral promontory.There were 8 patients of longitudinal fractures in sacral wings,which of 6 patients involving S1-2 and 2 patients involving S3.Three patients had transverse fractures in sacral promontories,with 2 located at S2 and 1 at S3.The sacral bone density increased in 5 cases,and the density was not changed in 3 cases.Conclusion Sacral insufficiency fracture had specific 18F-FDG PET/CT characteristics.
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Objective To investigate the feasibility of hydrogen proton magnetic resonance spectroscopy (1 H-MRS)for detection of Wallerian degeneration of the pyramidal tract after cerebral infarction.Methods Multiple metabolic indices including NAA,Cho, Cr of the bilateral cerebral peduncle were detected by using 1 H-MRS in 1 5 patients with unilateral middle cerebral artery infarction and 1 5 age-matched healthy volunteers,NAA/Cr,Cho/Cr were also calculated.Comparing the difference between cerebral infarction group and the control group ,the ROC curve was analyzed.Results The values of NAA/Cr in the ipsilateral cerebral peduncle of cerebral infarction patients were significantly lower than that of the contralateral,and there were significant differences between the two groups(P 0.05),the Cho/Cr values of the ipsilateral and the contralateral cerebral peduncle had no significant difference compared with the control group (P >0.05).Conclusion 1 H-MRS can detect Wallerian degeneration of the pyramidal tract after cerebral infarction.
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Objective To evaluate the importance of wide canal sign (increased anteroposterior diameter of the spinal canal at L5) in the MR diagnosis of lumbar isthmic spondylolisthesis.Methods One hundred cases of bilateral isthmic spondylolisthesis at L5 confirmed with conventional radiography and/or CT were randomly collected.Another age and sex matched 100 cases without spon-dylolisthesis were collected as control group.The sagittal canal diameters at the L1 and L5 levels were measured and analyzed for all 100 cases of bilateral isthmic spondylolisthesis and 100 control subjects.For each group,the sagittal canal ratio(defined as the maxi-mum anteroposterior diameter of the canal at L5 level divided by the diameter of the canal at L1 )was calculated and compared be-tween the two groups ,and anylyzed with ROC curve.Results The mean midline sagittal anteroposterior diameter was (22.3 ± 1.34)mm at L5 in patients with lumbar isthmic spondylolisthesis,and (18.8±1.57)mm in the control subjects.The sagittal canal ratio was 1.32 in the isthmic spondylolisthesis group and 1.12 in the control subjects,which was different significantly.ROC curve illustrated that the sagittal canal ratio 1.25 was a most meanful point with 88% sensitivity and 90% specificity.Conclusion The sag-ittal canal ratio at L5 is bigger than 1.25 meaning abnormally increased sagittal canal diameter (wide canal sign),which specifically indicates the presence of bilateral pars interarticularis defects.Using this sign can help to make correct MR diagnosis and differential diagnosis of isthmic spondylolisthesis .
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Objective To evaluate the value of susceptibility-weighted imaging (SWI)sequence in the diagnosis of metastatic en-cephaloma pre and after radiotherapy by comparing the appearance of the SWI and contrast-enhanced T1-weighted imaging(T1 WI). Methods Thirty-eight lung cancer patients with brain metastases underwent SWI and contrast-enhanced T1-weighted imaging re-spectively before and 2-3 months after radiotherapy.Evaluated the two methods by score(the score ranged from 0-3,0 represen-ted no showing,1 represented not showing clearly,2 represented could judging,3 represented showing obviously).Results Before radiotherapy,SWI detected 1 61 lesions of metastases and could obviously show tumor vascular in brain metastases (mean score 2.73±0.05).Contrast-enhanced T1 WI detected 1 61 lesions(mean score 1.93±0.04 ).SWI showed significantly higher score than enhanced T1 WI(P <0.05)through paired sample t test.After radiotherapy,SWI found 98 lesions (mean score 1.47±0.1 1 )and en-hanced T1 WI found 140 lesions (mean score 1.80±0.07),enhanced T1 WI had significantly higher score than SWI(P <0.05).Con-clusion SWI is superior to contrast-enhanced T1 WI to show the metastases before radiotherapy and can show tumor vascular in brain metastases obviously.SWI is inferior to enhanced T1 WI after radiotherapy.It has some value and may provide a new method for evaluating effects of radiotherapy.
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Objective To evaluate clinical and CT features of the 4 th lumbar vertebral spondylolisthesis (L 4DS ) as well as CT value in its diagnosis. Methods CT features of 36 cases of L 4DS were observed and interarticular distance (IAD) and facet joint angle (FJA) were measured and compared with control group.Results Patients with L 4DS mostly were over 40 years old. CT features included degenaration, spondylolisthesis and spinal canal stenosis. IAD and FJA were significantly narrowed. Conclusion CT axial scans combined with plain films,CTM and MPR clearly shows basic changes of L 4DS , providing useful details for clinical management. Narrow posterior vertebral part are important factors leading to L 4DS.
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Objective To establish stable and convenient atomic fluorescence spectrometry to determine selenium concentration.Methods The samples were digested by nitric acid-perchloric acid and the selenium was determined by hydride generation-atomic fluorescence spectrometry with step-flow injection technology in NaBH4 acid and 100 g/L K3Fe(CN)6 system.Results The relative standard deviation of the method was less than 5%,the concentration of detection limits was 0.81 ?g/L and the recovery rate ranged from 93.1% to 102.2%.Conclusion Atomic fluorescence spectrometry was convenient and reliable in determining solenium,the digest method of test tube was better than that of normal electrothermal board.