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Objective To improve the selection of flying cadets of the Air Force of People′s Liberation Army of China ( PLAAF) by analyzing the differences of medical identification of lumbar spondylolysis between PLAAF and the US Air Force ( USAF) .Methods Flight crew who had been checked for lumbar spondylolysis during hospitalization at the Air Force General Hospital between 2013 and 2015 were chosen.The results of their medical identification were compaired according to PLAAF and USAF Medical Standards Directory, and their differences and possible reasons were analyzed accordingly.Results The qualified rate of PLAAF was about 85%, which was very close to the standards of USAF, but the difference was not of any statistical significance(P>0.05).Conclusion The standards of our medical identification of lumbar spondylolysis was similar to those of USAF, suggesting that the selection of flying cadets can be improved.
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Objective To improve and determine the Medical Standards Directory of the Air Force of People′s Libera-tion Army of China( PLAAF) by analyzing the differences in lumbar spondylolysis and scoliosis between PLAAF and the US Air Force( USAF) .Methods All candidates of flying cadets participating in the final radiographic selection between 2013 and 2015 were chosen.They were judged to be qualified or not according to PLAAF and USAF Medical Standards Directory. Results The average morbility of lumbar spondylolysis and scoliosis in PLAAF was 47%and 30.3%respectively.Arnong those who were eliminated in China,86.0%and 92.5%could be regarded as qualified according to the standard of USAF in 2015.The difference was statistically significant (P<0.01).Conclusion Our selection standards for lumbar spondylol-ysis and scoliosis should be improved based on this study.
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Objective To investigate the correlation between the unilateral middle cerebral artery (MCA)stenosis ratio and cerebrovascular reserve(CVR) using computed tomography perfusion (CTP) and CO2 inhalation test in patients with unilateral middle cerebral artery stenosis.Methods CTP were performed in 31 patients who were diagnosed as unilateral middle cerebral stenosis before and after CO2 inhalation.The basal ganglia and radial dimension were selected as interested regions (thickness 8 mm).The value of cerebral blood flow (CBF) was measured and the mean CBF values of all interested regions in each MCA territory were harvested separately.Then the CVR of each MCA territory was calculated according to the following formula:CVR =(CBF after CO2 inhalation test-CBF before CO2 inhalation test)/ CBF before CO2 inhalation test × 100％.Patients were divided into two groups:the severe stenosis group and the moderate stenosis group.The association between the MCA stenosis ratio and the CVR values was investigated.Results In 31 patients,different changes of CBF were found in affected MCA territory after CO2 inhalation.CBF increased in 17 cases,unchanged in 2 cases and decreased in 12 cases.A decreased CVR was detected in 51.6％ of the patients(16/31) and more likely found in the severe stenosis group (13/19) than that in the moderate stenosis group(3/12,P =0.029).The degree of stenosis in MCA was also significantly correlated with the changes of CVR(r =0.423,P =0.018).Conclusions CVR is decreased in some patients with unilateral MCA stenosis and significantly correlates with the severity of stenosis in MCA.
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CMV,HHV-6,HHV-7 and HHV-8 DNA in unstimulated whole saliva from 245 HIV-infected subjects and 30 healthy controls were examined by nested-PCR assays.Prevalence of CMV,HHV-6,HHV-7 and HHV-8 in saliva of HIV-infected subjects was 34.7%, 83.3%,70.2% and 14.3% respectively,that of the controls 10.0%,56.7%,70.0% and 0% respectively(between 2 groups,P 0.05).Multi-infection was observed in all subject.
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Purpose To analyze the perfusion differences of different pancreatic diseases using the low-dose whole organ dynamic volume CT perfusion imaging, and to provide the evidence for the clinical application. Materials and Methods Twenty-eight patients suspected as pancreatic disease were applied by 640 layer volume CT perfusion imaging for the pancreas. Data were collected at the same time of bolus injection of contrast agent, then were analyzed by spatial alignment and perfusion calculation using the perfusion software. The time-density curve, blood perfusion flow diagram and tissue artery blood flow were obtained using the maximum slope method. Results Normal pancreatic tissue (n=9) blood flow was (117.04±12.05) ml/(min?100 ml), pancreatitis organizations (6 cases with acute pancreatitis and 3 cases with chronic pancreatitis) (118.67±37.18) ml/(min?100 ml), pancreatic carcinoma tissue (n=10) was (67.16±18.94) ml/(min?100 ml). There was significant difference among three groups (F=8.59, P0.05). The total dose of X-rays in the whole scanning process was 21.5-23.9 mSv. Conclusion Low-dose whole pancreas organ CT perfusion scan can quantitatively analyze the hemodynamic changes in pancreatic disease, which be of great value for evaluating changes in microcirculation during the treatment of pancreatic cancer.
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Purpose To explore the diagnostic value of double exponential model for pelvic lesions using 3.0T MRI for the diagnosis of pelvic lesion. Materials and Methods Fifty patients with pelvic lesions (30 benign cases and 20 malignant cases) underwent MR750-diffusion weighted imaging (DWI) scans, with b values of 0, 50, 300, 600, 800 and 1200 s/mm2, Functool-MADC software was used on AW 451 workstations for data processing, Slow ADC value, Fast ADC value, Standard ADC value, Fraction of fast ADC value were recorded and compared between benign and malignant lesions, and Standard ADC images were fused with axial T2 fat-suppressed images. Results Slow ADC values [(1.83±0.86)×10-3 mm2/s] and Standard ADC values [(1.79±0.78)×10-3 mm2/s] of benign lesions were larger than those of the malignant lesions [Slow ADC values:(1.05±0.31)×10-3 mm2/s;Standard ADC values:(1.13±0.39)×10-3 mm2/s] (t=3.90, 3.51;P<0.01), and the difference of Slow ADC value was largest between benign and malignant lesions. Slow ADC values of both benign and malignant lesions were significantly less than the Fast ADC values [benign:Slow ADC value=(1.83±0.86)×10-3 mm2/s, Fast ADC value=(16.95±8.63)×10-3 mm2/s; malignant: Slow ADC value=(1.05±0.31)×10-3 mm2/s, Fast ADC value=(15.12±9.90)×10-3 mm2/s] (t=-10.40,-6.29;P<0.01). Conclusion Double exponential decay model is capable of differentiating benign and malignant pelvic tumors, thus is of great significance for clinical preoperative diagnosis.
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Objective To evaluate dual-source dual-energy CT(DSCT) for the differentiation of urinary stone composition in vitro. Methods Ninety-seven urinary stones were obtained by endoscopic lithotripsy and scanned using dual-source dual-energy CT. The stones were divided into six groups according to infrared spectroscopy stone analysis: uric acid ( UA ) stones ( n = 10 ), cystine stones ( n = 5 ), struvite stones( n = 6), calcium oxalate ( CaOx ) stones ( n = 22 ), mixed UA stones ( n=7 ) and mixed calcium stones(n=47). Hounsfield units (HU) of each stone were recorded for the 80 kV and the 140 kV datasets by hand-drawing method. HU difference, HU ratio and dual energy index ( DEI ) were calculated and compared among the stone groups with one-way ANOVA. Using dual energy software to determine the composition of all stones, results were compared to infrared spectroscopy analysis. Results There were statistical differences in HU difference [(-17±13), (229±34),(309 ±45), (512 ±97), (201±64)and (530±71) HU respectively], in HU ratio (0.96±0.03, 1.34 ±0.04, 1.41 ±0.03, 1.47 ±0.03,1.30±0.07, and 1.49 ±0.03 respectively), and DEI( -0.006 ±0.004, 0.064 ±0.007, 0.080 ±0. 007, 0. 108±0.011 ,0. 055 ±0.014 and 0. 112 ±0.008 respectively ) among different stone groups(F=124. 894,407.028, 322. 864 respectively, P ＜0. 01 ). There were statistical differences in HU difference,HU ratio and DE1 between UA stones and the other groups( P ＜ 0. 01 ). There were statistical differences in HU difference, HU ratio and DEI between CaOx or mixed calcium stones and the other four groups (P＜0. 01 ). There was statistical difference in HU ratio between cystine and struvite stones ( P ＜ 0. 01 ). There were statistical differences in HU difference, HU ratio and DEI between struvite and mixed UA stones (P＜0. 05 ). Dual energy software correctly characterized 10 UA stones, 4 cystine stones, 22 CaOx stones and 6 mixed UA stones. Two struvite stones were considered to contain cystine. One cystine stone, 1 mixed UA stone, 4 struvite stones and 47 mixed calcium stones were considered to contain oxalate. Conclusions DSCT has the ability to differentiate urinary stone composition in vitro. With dual energy software, the UA, cystine and mixed UA stones can be differentiated from other types of stones.
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BACKGROUND:To introduce the scanning technique and imageologieal signs of multi-slice spiral CT angiography in the diagnosis of venous thromboembolism,and concomitantly evaluate its apphcadon value and advantage in the early diagnosis of venous thromboembolism.METHODS:Using the terms"venous thromboembolism,pulmonary thromboembolism,CT angiography",the authors computer-retrieved Medline to identify studies published between January 1998 and October 2007 in the English language.At the same time,we searched the Wanfang database with the same terms in the Chinese language by hand and computer forstudies between January 2000 and October 2007.A total of 228 manuscripts Were obtained,and 24 of them corresponded to the inclusive criteria.RESULTS:Using collection technique and in conjunction with high-quality three-dimensional reconstructed images,multi-slice spiral CT can clearly reveal the distal branches of pulmonary artery,achieving subsegmental-level diagnosis of Duhnonary thromboembolism.There was no remarkable difference in the sensitivity for diagnosing pulmonary thromboembolism between thin-slice spiral CT and pulmonary artery angiography.The sensitivity and specificity of thin-slice spiral CT is higher compared to pulmonary ventilation-perfusion radioisotope scanning.When eliminating acute pulmonary thromboembolism,spiral CT is a promising first-ehoicemethod.CONCLUSION:Spiral CT is characterized by rapid scanning,clear image,and without omission of small foci.Spiral CT angiography is a safe,rapid,non-invasive,and effective method for the diagnosis of venous thromboembolism.
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Objective To evaluate the effieaey of test bolus technique with multi-slice spiral CT (MSCT) for determining the optimal scan delay time in CT Hepatic artery (HA)-portal vein (PV) angiography and multi-phase scanning.Methods MSCT liver angiography and multi-phase scanning were performed in 187 patients divided randomly into two groups.In group A (n =59),the scan delay time was set according to the subjective experiences of operators; in group B (n=128),the scan delay time was determined by test bolus technique.Abdominal aorta and superior mesenteric,vein were selected as target blood vessels,and 50 HU was set as enhancement threshold value.20 ml contrast agent was injected intravenously and time-density curve of target blood vessels were obtained,then HA-PV scanning delay time were calculated respectively.The quality of CTA images obtained by using these 2 methods were compared and statistically analysed using Chi-square criterion.Resuits For hepatic artery phase,the images of group A are:excellent in 34(58%),good in 17(29%),and poor in 8 (13%),while those of group B are excellent in 128( 100%),good in 0(0%),and poor in 0(0%).For portal vein phase,the images of group Aare:excellent in 23(39%),good in 27(46%),and poor in 9(15%),while those of group B are excellent in 96 (75%),good in 28 (22%),and poor in 4 (3%) respectively.There was statistically significant difference between the ratios of image quality in group A and group B (X2=14.97,9.18,P < 0.05).Conclusion Accurate scan delay time was best determined by using test bolus technique,which can improve the image quality of liver angingraphy and multi-phase scanning.
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BACKGROUND: The MRJ studies of acute myocardial infarction (AMI)were more frequently focused on the changes of myocardial perfusion. OBJECTIVE: To investigate the characteristics of infarction and myocardial reperfusion in MRI, and make comparison of them with the results of their staining pathologic sections. DESIGN: Completely randomized grouping design and randomized controlled study. SETTING: Magnetic Resonance Department of Air-force General Hospital of Chinese PLA and Radiological Department of General Hospital of Chinese PLA. MATERIALS: The experiment was completed in the Medical Animal Experimental Center, General Hospital of Chinese PLA in December 2003.Fourteen miniature pigs were divided into 2 groups: infarction group and reperfusion group with 7 pigs in each group. One-month before and after the operation, MRI was performed in order to strengthen the scanning examination. One-month after operation, axial plane pathologic slices, which were corresponding to the MRI, were given TTC and SE staining. According to the TTC staining results, samples of the infarcted myocardium (corresponding to the anterior wall of the left ventricular) and normal myocardium (corresponding to the posterior wall of the left ventricular) were taken and given HE staining to observe the extent of infracted myocardium. MAIN OUTCOME MEASURES: The changes in cardiac shape and function and the changes of myocardial T1 and T2 relaxation time. RESULTS: Fourteen Chinese miniature pigs were used with 7 in each group. ①Relaxation time of T1 and T2 of infarcted myocardium in infarction group was obviously longer than that of thenormal myocardium [1 159.54±78.67, (60.15±6.31) ms, 1 056.15±70.95, (47.46±7.94) ms, t=2.63,5.38, P＜ 0.05, 0.01] and that of the infarcted myocardium in reperfusion group was also obviously longer than that of normal myocardium [1 171.14±139.98,(56.64±6.16) ms, 1 074.64±97.61, (44.57±4.25) ms, t=2.64, 6.24, P ＜ 0.05,0.01].②MRI in single infracted myocardium and reperfused infracted myocardium was both changed obviously,but without significant differences in relaxation time and stress.Dilatation of left ventricle in single infracted group was more obviously than that in the reperfusion infracted group.③Theresult of MRI was coincidence with that examinated with TTC staining CONCLUSION:①MRI is a useful imaging modality in the evaluation of AMI and the left ventricle remodeling after myocardial infarction.②It is significant for reperfusion to treat remodeling of left ventricle after acute myocardium infarction.③There is good correlation between MRI and pathological examination.
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Objective To study renal involvement in hepatic glycogen storage disease(GSD) in childhood. Methods One hundred and eight patients aged less than 21 years old with type Ⅰa GSD (54 cases), type Ⅲ (29 cases) and uncertain type hepatic GSD (25 cases). Urine analysis, urine albumin, urine protein of 24 h, urine ?_2-MG, BUN, creatinine, Ccr were evaluated. Results Of 108 patients with hepatic GSD, 16 patients (20.8%) had proteinuria proven by urine albumin or urine protein of 24 h, their ages first found proteinuria were 8～15 years. Two 15-year-old patients had proteinuria over 1.0g/24h. Among 72 patients, urine ?_2-MG of 51 cases (70.8%) increased (175～10 623mg/L), and the mean urine ?_2-MG of type Ⅰ a GSD was much higher than that of type Ⅲ GSD, 4138.2 and 1790.1mg/L respectively. Of 91 patients, 10 had renal insufficiency, 1/10 (15-year-old girl) had heavy proteinuria (3.5g/24h), elevated BUN (9.3mmol/L) and Scr(1061 ?mol/L). Five elder patients (11～21 years old) had hematuria with renal colic caused by renal calculus. Conclusions Persistent protenuria, increased urine ?_2-MG, decreased Ccr, and renal stones are common complications of hepatic GSD in childhood. Renal function should be thoroughly evaluated during follow-up.
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Objective To evaluate the MR manifestation to provide guidance for the clinical diagnosis of adenomyosis.Methods The MR images of 43 cases of adenomyosis which were proved by operation and pathology were reviewed.Results Among the 43 cases of adenomyosis,26 cases were of diffuse adenomyosis and 17 of focal adenomyosis.Leiomyoma(21 cases),intra-pelvic cavity chocolate cyst (17 cases)and ovarian cyst(15 cases)were concurrently found in this group of patients.The MRI of diffuse adenomyosis demonstrated an enlarged uterus and widened uterine junction zone with ill-defined margin between junction zone and myometrium.The adenomyosis lesions showed iso-signal intensity on T_1 weighted images and iso-signal or slight low signal intensity on T_2 weighted images with scattered hyper- intense foci.The uterine cavities were irregularly narrowed due to compression of thickening junction zone.The lesions showed mild con- trast enhancement on contrast-enhanced MR images.The MRI of focal adenomyosis displayed localized myometrial masses with ill-defined margin with widening of junction zone.The lesions were round or oval in shape with iso-signal intensity on T_1 weighted images and inho- mogeneous slightly low signal on T_2 weighted images.Multiple scattered hyperintense foci could be found in the mass on the T_2 weighted images.The lesions had mild contrast enhancement on contrast-enhanced MR images.The concurrent leiomyoma,intra-pelvic cavity choc- olate cyst and ovarian cyst were also displayed by MR imaging.Conclusion The widened junction zone is the characteristic change of ade- nomyosis.MRI can demonstrate the types,size and concurrent changes in adenomyosis,and is a useful noninvasive imaging method for the diagnosis of adenomyosis.
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Objective To evaluate the clinical application of spiral CT pulmonary angiography(SCTPA) in the diagnosis of pulmonary embolism(PE) and its limitation.Methods 52 cases of PE were analyzed.SCTPA were performed in all cases with slice thickness 3 mm,pitch 1.5~2.0,scanning time 0.8 s,reconstruction thickness 1mm.The reconstructions of SCTPA included MIP,MPR and SSD.Results 2898 pulmonary arteries in 52 cases were observed.The direct manifestations of PE were showed in 927 pulmonary arteries(32.0%) by SCTPA,in which superior segmental and inferior segmental of pulmonary arteries were involved respectively.The indirect manifestations of PE were showed by plain scan in 113 cases.Conclusion SCTPA is a high effective and noninvasive method in the diagnosis of PE especially for the PE of superior segmental.