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Objective:To use quantitative computed tomography (QCT) technology to measure the bone mineral density of the spine of the Chinese healthy population, and to explore its correlation with hemoglobin and serum albumin.Methods:The data in this study came from the China Health Quantitative CT Big Data Project (China Biobank). The spine bone density was measured by using QCT Pro Image Analysis System and all cooperating centers used the European spine phantom (NO.145) for quality control. Total of 50 053 healthy persons who met the criteria for entry were selected as the research subjects. The subjects were divided into 7 groups according to age. The general data, spine bone density, serum albumin, hemoglobin of the subjects were collected. The single-factor analysis of variance, Pearson correlation analysis and multi-classification logistic regression model were applied to analyze the correlation between bone density and hemoglobin and serum albumin.Results:The bone mineral density of healthy people decreased with age ( P<0.05), and there were significant differences in hemoglobin, serum albumin and body mass index (BMI) among different age groups (all P<0.05). Linear correlation analysis showed that there were positive correlation between bone mineral density and hemoglobin in healthy males in different age groups ( r=0.086, 0.101, 0.076, 0.090, 0.072, 0.123, 0.100, all P<0.01). There were negative correlation between bone mineral density and hemoglobin in certain age groups in women (40-49 years group: r=-0.027; 70-79 yearsgroup: r=-0.077; both P<0.05). And corelation were found between bone mineral density and serum levels of albumin in certain age groups of healthy subjects (among men, 30-39 years group: r=-0.048; 40-49 years group, r=-0.027; 70-79 years group, r=-0.051; among women, 30-39 years group: r=-0.044; 40-49 years group, r=-0.042; 50-59 years group, r=-0.086; 70-79 years group, r=-0.070; all P<0.05). After adjusting for age and BMI, the multi-category logistic regression analysis showed that the hemoglobin level was protective factor of normal bone density ( OR=1.022, 95% CI:1.017-1.027) and decreased bone density ( OR=1.012, 95% CI:1.007-1.016) in healthy males, and the serum albumin was risk factor for normal bone density ( OR=0.926, 95% CI:0.905-0.948) and decreased bone density ( OR=1.006, 95% CI:0.951-1.011) in healthy women. Conclusion:There is a correlation between bone mineral density and hemoglobin and serum albumin in Chinese healthy population. Hemoglobin is a protective factor for bone mineral density in men, and serum albumin is a risk factor for bone mineral densityin women.
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Objective:To establish the normal reference value of lumbar bone mineral density (BMD) under quantitative CT (QCT) in Chinese healthy adult females and to explore the regional differences.Methods:Total of 35 431 healthy women who met the inclusion criteria of Chinese health quantitative CT big data program were selected in this study. The BMD of the central plane of L 1 and L 2 vertebrae was measured by Mindways′s QCT system, and the mean value was taken. One-way analysis of variance was used to compare the BMD differences of lumbar vertebrae in women of different ages and regions. The subjects were grouped by an age interval of 10 years, and the level of BMD in different regions of the same age group were compaired. Results:The peak BMD of Chinese healthy adult women appeared in the age group of 20-29 years (Northeast China(183.01±24.58) mg/cm 3, North China (188.93±24.80) mg/cm 3, East China (187.54±27.71) mg/cm 3, South China (186.22±33.72) mg/cm 3, Central China (176.33±24.91) mg/cm 3, Southwest China(182.25±28.00) mg/cm 3), and then it decreased with age. The level of BMD in different regions decreased with the age. Before the age of 70 years, BMD in Central and Southwest China was always at a low level((176.23±24.91) to (90.38±28.12) mg/cm 3, 182.25±28.00 to (88.55±25.68) mg/cm 3), lower than those in Northeast China ((183.01±24.58) to (99.69±27.85) mg/cm 3), North China ((188.93±24.80) to (95.89±26.12) mg/cm 3), East China ((187.54±27.71) to (95.65±27.86) mg/cm 3). After 70 years of age, BMD tended to be the same in different regions ( P>0.05). The BMD values in Central China and Southwest China were similar in the age group of 40-60 years ( P>0.05). The BMD values in the health adult femles in the age group of 60 years in different regions of Chinawere all lower than those of bone mass abnormality (all P<0.05). The detection rate of osteoporosis in females over 50 years was the highest in Southwest China (25.65%) and it was the lowest in North China (17.30%). Conclusions:This study establishes reference values of BMD under QCT in healthy Chinese women, which can be used as a reference basis for identifying women with low BMD who are at risk of osteoporosis. The BMD value is the lowest in Southwest China and the highest in South China.
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Objective:To describe the baseline characteristics of the subjects enrolled in the China Quantitative CT (QCT) big data program in 2018—2019.Methods:Based on baseline data from the Chinese health big data project from January 2018 to December 2019 from the eligible enrolled population, measurements of bone mineral density (BMD) and visceral adipose tissue (VAT) were performed using Mindways′ QCT Pro Model 4 system. The baseline data of age, gender, regional distribution, height, weight, abdominal circumference, blood pressure, blood routine and blood biochemical tests were analyzed. And the single factor analysis of variance (ANOVA) was used to check the age related trend of BMD and VAT in both genders.Results:After screening the inclusion exclusion criteria and outliers of the main indicators, 86 113 people were enrolled in the project. The enrollment rate was 92.47%, including 35 431 (41.1%) women and 50 682 (58.9%) men, and the ratio of men to women was 1.43. The mean age was (50.3±12.7) years in all the subjects, and it was (50.2±12.8) years and (50.4±12.5) years in men and women, respectively, and there was no statistical difference between the two genders ( P>0.05). Total of 43 833 people were enrolled in east China, it was the largest group by region (50.90%), it was followed by central China (16 434 people, 19.08%), and the number of people enrolled in Northeast China was the lowest (2 914 people, 3.38%). The rate of completing of health information indicators related to the main outcome of the study were all above 70%, and there were significant differences between men and women (all P<0.05). The mean BMD was (139.33±46.76) mg/cm 3 in women, (135.90±36.48) mg/cm 3 in men, which showed a decreasing trend with age in both gender (both P<0.001); the mean intra-abdominal fat area was (116.39±56.23) cm 2 in women, (191.67±77.07) cm 2 in men, and there was an increasing trend with age in both men and women (both P<0.001). Conclusions:There are gender differences in BMD and VAT measured by QCT with different age tendency, and there are gender differences in health information index. Regional factors should also be taken into account for regional differences in the inclusion of data.
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Objective:To explore the value of synthetic MRI in quantitative monitoring of knee joint structural and cartilage changes of amateur marathon runners before and after the whole marathon.Methods:Totally 26 amateur marathon enthusiasts from Zhuhai City, Guangdong Province were recruited from October 2019 to January 2020. The right knee joints were scanned 1 week before the race and within 48 h after the race. The scanning sequence included the three-dimensional proton density weighted image with isotropic (3D-CUBE-PD) sequence and synthetic MRI sequence. The conventional contrast weighted images T 1WI, T 2WI, proton density (PD) weighted imaging, short-T 1 inversion recovery (STIR) and T 1, T 2, PD mapping were obtained by the latter scans. The 3D-CUBE-PD sequence was used as a reference to evaluate the detection of knee joint lesions. The knee articular cartilage was divided into 8 subregions: central medial femoral condyle (CMFC), posterior medial femoral condyle (PMFC), central lateral femoral condyle (CLFC), posterior lateral femoral condyle (PLFC), medial tibia plateau (MTP), lateral tibia plateau (LTP), patella and trochlear. Based on the synthetic MRI quantitative mapping, the T 1, T 2 and PD values of each cartilage subregion were measured independently by 2 radiologists. The ICC was used to evaluate the consistency of the measurement between observers. The T 1, T 2 and PD values of knee cartilage before and after marathon exercise were compared by Wilcoxon signed rank test. Results:The 2 radiologists had good consistency in the measurement of T 1, T 2 and PD values of knee articular cartilage with the ICC values of 0.912, 0.933 and 0.954, respectively. The synthetic MRI quantitative mapping sequence can detect all cartilage damage ( n=3) and joint effusion ( n=15), and 7 of 9 meniscus injuries were detected. The T 1, T 2 and PD values of the knee cartilage as a whole before the race were higher than those after race, and the differences were statistically significant (all P<0.05). The T 1 values were statistically significant except patellar cartilage and trochlear cartilage, and T 2 values were significantly different in the CMFC, LTP, MTP ( P<0.05). Conclusion:Synthetic MRI has a good display of knee joint structural lesions, and its quantitative parameters T 1, T 2 and PD can detect the changes of knee cartilage before and after marathon.
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Objective:To evaluate the value of MAGiC STIR sequence inassessing bone marrow edema (BME) of the sacroiliac joint (SIJ) in ankylosing spondylitis (AS) patients.Methods:Twenty two AS patients from the Affiliated Fifth Hospital of Sun Yat-sen University from September 2019 to January 2020 underwent MR scanning, consisting of T 2WI fat-suppressed (FS) sequence and MAGiC sequence. Each SIJ was divided into four quadrants for analysis on oblique coronal MR image. Two radiologists [middle-higher seniority levels (radiologist 1 and radiologist 2) reviewed image sets of two sequences [T 2WI FS and MAGiC short T 1 inversion recovery (STIR) sequence] independently at separate times, using Hermann-Braun scoring system for degree of BME and summing numbers of quadrants based on BME findings. Disagreements were resolved to reach an agreement for final results.Assessments were repeated two weeks later by radiologist 2. Intra-class correlation coefficients (ICC) were calculated to assess the inter-and intra-observer agreement for the degree of BME and numbers of positive BME quadrants in the MAGiC STIR sequence, respectively. The differences between the two sequences for the degree of BME and numbers of positive BME quadrants were analyzed with Wilcoxon signed-rank test and Chi-square test, respectively. Taking the results of T 2WI FS sequence as a reference standard, the ROC curve was drawn, sensitivity, specificity, positive predictive value and negative predictive value in the detection of BME were calculated for the MAGiC STIR sequence. Results:Nineteen AS patients including 38 sacroiliac joints were enrolled in our study, being divided into 152 quadrants. Inter-and intra-observer agreement for the degree of BME and inter-observer agreement for numbers of positive BME quadrants in the MAGiC STIR sequence were all good (ICC=0.936, 95%CI 0.912-0.953, P<0.001; ICC=0.910, 95%CI 0.878-0.934, P<0.001; ICC=0.876, 95%CI 0.833-0.909, P<0.001). The difference between the two sequences for the degree of BME in quadrants was statistically significant ( Z=-3.132, P=0.002). But there was no statistically significant difference between sequences for numbers of quadrants in detecting BME (χ2=0.244, P=0.622). Area under the ROC curve of MAGiC STIR sequence in diagnosis of BME was 0.920 ( P<0.001). Sensitivity, specificity, positive predictive value and negative predictive value for the MAGiC STIR sequence in the detection of BME were 82.0%, 95.1%, 89.1% and 91.5%, respectively. Conclusion:MAGiC STIR sequence can be used to evaluate bone marrow edema of SIJ in AS patients with high sensitivity and specificity.
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OBJECTIVE@#To develop and validate radiomics models based on non-enhanced magnetic resonance (MR) imaging for differentiating chondrosarcoma from enchondroma.@*METHODS@#We retrospectively evaluated a total of 68 patients (including 27 with chondrosarcoma and 41 with enchondroma), who were randomly divided into training group (=46) and validation group (=22). Radiomics features were extracted from TWI and TWI-FS sequences of the whole tumor by two radiologists independently and selected by Low Variance, Univariate feature selection, and least absolute shrinkage and selection operator (LASSO). Radiomics models were constructed by multivariate logistic regression analysis based on the features from TWI and TWI-FS sequences. The receiver-operating characteristics (ROC) curve and intraclass correlation coefficient (ICC) analyses of the radiomics models and conventional MR imaging were performed to determine their diagnostic accuracy.@*RESULTS@#The ICC value for interreader agreement of the radiomics features ranged from 0.779 to 0.923, which indicated good agreement. Ten and 11 features were selected from the TWI and TWI-FS sequences to construct radiomics models, respectively. The areas under the curve (AUCs) of TWI and TWI-FS models were 0.990 and 0.925 in training group and 0.915 and 0.855 in the validation group, respectively, showing no significant differences between the two sequence-based models (>0.05). In all the cases, the AUCs of the two radiomics models based on TWI and TWI-FS sequences and conventional MR imaging were 0.955, 0.901 and 0.569, respectively, demonstrating a significantly higher diagnostic accuracy of the two sequence-based radiomics models than conventional MR imaging (<0.01).@*CONCLUSIONS@#The radiomics models based on TWI and TWI-FS non-enhanced MR imaging can be used for the differentiation of chondrosarcoma from enchondroma.
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Humans , Chondroma , Chondrosarcoma , Magnetic Resonance Imaging , ROC Curve , Retrospective StudiesABSTRACT
Objective@#To explore the factors, characteristics and imaging manifestations of ankle joint injury in amateur marathoners (no formal training and no marathon career).@*Methods@#From December 2018 to March 2019, the amateur marathon runners in Guangdong Zhuhai had been recruited as research subjects according to the study inclusion and exclusion criteria. The questionnaires were used to collect relevant data, and the subjects underwent MRI scans of the ankle joint. The ankle joint special phased array coils were used to perform fast spin echo sequence (TSE) coronal T1WI and proton density-weighted fat-suppression sequence (PDWI-FS). Axial, coronal and sagittal scans, three-dimensional-double echo steady-state sequence (3D-DESS) and three-dimensional variable flip angle fast spin echo sequence (3D-SPACE) scans were also acquired. The results of the examination were independently analyzed by two radiologists (5 and 17 years of work experience, respectively) on the ligament, tendon, bone marrow and ankle joint injuries. When they had inconsistent views, the diagnosis provided by the third radiologist (27 years of work experience) was considered a final diagnosis. The relationship between ankle injury and different running postures, the number of participating in marathons and training intensity was analyzed, and the independent sample χ2 was used for statistical analysis. The consistency of two radiologists was tested by Kappa test.@*Results@#According to the inclusion and exclusion criteria, 39 subjects were included, with 64 ankles totally, 35 right ankles and 29 left ankles. MRI showed that (1) Ligament injuries: 28 ankles were anterior talofibular ligament injuriy;50 ankles were posterior talofibular ligament injury; 60 ankles the calcaneofibular ligament injuries and 54 ankles were deltoid ligament injuries, without complete injury. (2) Tendon sheath effusion and injuries: peritendinous effusion was common, with 47 flexor hallucis longus tenosynovitis, 49 posterior tibialis tenosynovitis, 37 flexor digitorum longus tenosynovitis, 7 peroneus longus tenosynovitis and 5 peroneus brevis tenosynovitis. (3) Synovitis effusion: 43 posterior ankle synovitis and local effusion. (4) Others: cartilage injury in 2 ankles, bone marrow edema in 8 ankles, and among them stress fracture in 2 ankles. The two radiologists had good consistency with the Kappa value of 0.91. Regarding the running posture, the incidence of ligaments injuries was obviously higher in those who landed on the hind foot than in those landed on front and middle foot,and the difference was statistically significant(P=0.013, χ2 value was 6.191).The incidence of tendon injuries was higher in those who landed on the front middle foot than in those landed on the hind foot, and the difference was statistically significant (P=0.029, χ2 value was 4.775). Those with larger training (training running ≥300 km/month) had significant ankle injury (P=0.005, χ2 value was 7.844).@*Conclusion@#The MRI features of ankle joint injuries in amateur marathon volunteers are related to different running postures and training intensity.
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Objective To explore the factors, characteristics and imaging manifestations of ankle joint injury in amateur marathoners (no formal training and no marathon career). Methods From December 2018 to March 2019, the amateur marathon runners in Guangdong Zhuhai had been recruited as research subjects according to the study inclusion and exclusion criteria. The questionnaires were used to collect relevant data, and the subjects underwent MRI scans of the ankle joint. The ankle joint special phased array coils were used to perform fast spin echo sequence (TSE) coronal T1WI and proton density?weighted fat?suppression sequence (PDWI?FS). Axial, coronal and sagittal scans, three?dimensional?double echo steady?state sequence (3D?DESS) and three?dimensional variable flip angle fast spin echo sequence (3D?SPACE) scans were also acquired. The results of the examination were independently analyzed by two radiologists (5 and 17 years of work experience, respectively) on the ligament, tendon, bone marrow and ankle joint injuries. When they had inconsistent views, the diagnosis provided by the third radiologist (27 years of work experience) was considered a final diagnosis. The relationship between ankle injury and different running postures, the number of participating in marathons and training intensity was analyzed, and the independent sample χ2 was used for statistical analysis. The consistency of two radiologists was tested by Kappa test. Results According to the inclusion and exclusion criteria, 39 subjects were included, with 64 ankles totally, 35 right ankles and 29 left ankles. MRI showed that (1) Ligament injuries: 28 ankles were anterior talofibular ligament injuriy;50 ankles were posterior talofibular ligament injury; 60 ankles the calcaneofibular ligament injuries and 54 ankles were deltoid ligament injuries, without complete injury. (2) Tendon sheath effusion and injuries: peritendinous effusion was common, with 47 flexor hallucis longus tenosynovitis, 49 posterior tibialis tenosynovitis, 37 flexor digitorum longus tenosynovitis, 7 peroneus longus tenosynovitis and 5 peroneus brevis tenosynovitis. (3) Synovitis effusion: 43 posterior ankle synovitis and local effusion. (4) Others: cartilage injury in 2 ankles, bone marrow edema in 8 ankles, and among them stress fracture in 2 ankles. The two radiologists had good consistency with the Kappa value of 0.91. Regarding the running posture, the incidence of ligaments injuries was obviously higher in those who landed on the hind foot than in those landed on front and middle foot,and the difference was statistically significant(P=0.013, χ2 value was 6.191).The incidence of tendon injuries was higher in those who landed on the front middle foot than in those landed on the hind foot, and the difference was statistically significant (P=0.029, χ2 value was 4.775). Those with larger training (training running ≥300 km/month) had significant ankle injury (P=0.005, χ2 value was 7.844). Conclusion The MRI features of ankle joint injuries in amateur marathon volunteers are related to different running postures and training intensity.
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Objective Early evaluate the feasibility and reproducibility of sorafenib-targeted therapy for hepatocellular carcinoma by RECIST1.1, mRECIST and three-dimensional volume measurement. Methods Seventy patients with pathology or typical imaging findings confirmed as hepatocellular carcinoma along with the sorafenib-targeted treatment for more than 2 months between October 2004 to April 2017 in the Fifth Affiliated Hospital of Sun Yat-sen University were retrospectively analyzed. Patients underwent chest, abdominal and pelvic CT scans and enhanced scans before and after 2 weeks of sorafenib treatment. Two physicians used RECIST 1.1, mRECIST, and volume measurement criteria to evaluate the efficacy of treatment. According to their averaged results, the patients were divided into two groups (control group and non-control group). Kaplan-Meier survival analysis was used to compare the prognostic values between different response evaluation criterias for early predicting the efficacy of sorafenib-targeted therapy in advanced hepatocellular carcinoma. Kappa test was used to assess the efficacy response consistency in intra-group and inter-group. Results Based on mRECIST and RECIST 1.1 measurements, the control group included 34 cases, and the non-control group included 36 cases. Based on semi-automatic volume measurement, the control group included 38 cases, and the non-control group included 32 cases. Before the treatment with sorafenib, the RECIST 1.1 and mRECIST methods were used. There was a high degree of consistency between the two doctors (Kappa values were 0.79 and 0.71, respectively), and the semi-automatic volume measurement method was extremely consistent (Kappa value was 0.90); the consistency in intra-observer by three different methods was extremely high (Kappa values were 0.91, 0.85, 0.97, respectively). After the treatment with sorafenib, the consistency between the two radiologists using RECIST 1.1 measurement was high (Kappa value was 0.65), the consistency of mRECIST measurement was moderate (Kappa value was 0.52), and the consistency of tumor volume measurement was extremely high (Kappa The value was 0.83), the consistency in intra-observer using the above three methods was high or very high (Kappa values were 0.86, 0.74, 0.90, respectively). The RECIST 1.1 and mRECIST measurements were less sensitive in early evaluation of sorafenib-targeted treatment, and there was no significant difference between the control group and the non-control group (P=0.578 and 0.613) while the semi-automatic volumetric measurement was sensitive (P=0.004). Conclusion Semi-automated three-dimensional volume measurement which has better intra-and inter-group consistency and reproducibility can reflect the efficacy of sorafenib-targeted therapy for hepatocellular carcinoma in early stage.
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Objective To discuss the imaging features of parietal bones atrophy,and to improve the understanding of this disease. Methods Clinical and imaging data of 8 patients with parietal bones atrophy were analyzed retrospectively.Age ranged 66-90 years with median age 76 years.CT scans were performed in all cases,and CT enhanced examination in 1 case.MRI examination were performed in 3 cases,in which MRI enhanced examination in 2 cases.Imaging characteristics were analyzed along with a review of the current literature.Results Bilateral parietal sympathetic involvements were found in 4 cases,unilateral parietal involvement in 4 cases,in which the left parietal bone was found in 2 cases and the right side in other 2 cases.The lesions ranged from 2.4 cm to 7.1 cm.On CT and MRI images,the external table of the parietal bones showed symmetrical impression,the diploe revealed thinner and the inner table was intact,which presented"Step change".Two of these patients were followed up,in which 1 case become severe atrophy,and the other case was no significant change.Nothing was showed in the relative scalp and soft tissue.Conclusion According to different degrees of thinning of parietal bones,combined with specific age,symmetrical parietal bone impression should be considered.
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Objective To evaluate the diagnostic value of related contrast material(Rel.CM)of the dual-energy CT (DECT) virtual noncalcium (VNCa) for detecting acute traumatic bone marrow edema in knee joint.Methods A total of 17 patients(18 knees)with definite trauma history and knee joint disorders were prospectively enrolled. Conventional CT, VNCa and MRI images were obtained by MRI and DECT scan. Each knee was divided into 12 regions, respectively, to observe the performance of MRI and VNCa images. The diagnostic efficacy of different Rel. CM values (1.25, 1.45, 1.75) was analyzed for the knee traumatic bone marrow edema,select the best Rel.CM value.And the CT values of bone marrow and bone marrow damage were measured on VNCa of the optimal Rel. CM parameters. Using ROC to evaluate the efficacy of VNCa in different Rel.CM values for diagnosing traumatic bone marrow edema,the difference of CT value between bone marrow lesion and bone marrow in normal region of bone marrow was obtained by using rank sum test. Results DECT and MRI were performed in 17 patients (18 knees). Eighteen knees were divided into 216 areas.MRI showed 94 areas of bone marrow edema,including 35 in distal portion of femur, 59 in proximal tibia. Rel.CM values of 1.25, 1.45, 1.75 of the VNCa map were used to diagnose traumatic bone marrow edema in the knee with the area under the ROC curve of 0.643, 0.871, 0.656, respectively. Rel.CM with 1.45 VNCa diagram was the most accurate. The CT values of the bone marrow edema region and the normal region were -64.3(-20.6 to-90.8)HU,-93.4(-70.5 to-120.7)HU, respectively, on the VNCa graph with the optimal Rel.CM parameters (1.45) (Z=-8.270, P<0.05). Conclusions The VNCa image with a Rel.CM value of 1.45 has a better diagnostic performance for traumatic bone marrow edema in knee joint. CT value measurement in VNCa image can be used for quantitative analysis of traumatic bone marrow edema.
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Objective To evaluate the feasibility of T2 *mapping T2 *value combined with DWI ADC value in quantitative assessment of the activity of sacroiliitis.Methods 30 patients diagnosed with ankylosing spondylitis (AS)were divided into 2 groups as acute group (n=17)and chronic group (n=13)according to the BASDAI scores of the clinical severity of disease.And 20 healthy adults were recruited as control group.All groups were examined by MR with traditional sequence,T2 *mapping and DWI in the sacroiliac joint.The T2 *value and ADC value of the bone marrow edema region and normal region were measured.Furthermore,the imaging data and the clinical scores were statistical analysis and compared among three groups.Results T2 *values and ADC values in acute group of AS patients were higher than chronic group (P0.05).Positive correlation between ADC value and BASDAI was observed in patients group.Conclusion T2 *mapping combined with DWI imaging in AS is beneficial for early diagnosis and quantitative analysis of the activity of sacroiliitis.
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BACKGROUND:Magnetic resonance diffusion tensor imaging can display the dispersion changes of peripheral nerve injury and be used to conduct quantitative research, so it has good application prospects in displaying the nerve injury and regeneration. OBJECTIVE:To investigate the possibility of magnetic resonance diffusion tensor imaging of rabbit acute sciatic nerve traction injury, and to figure out the value of diffusion tensor parameters in the diagnosis of peripheral nerve injuries and to reveal the pathologic basis. METHODS:The right hind limb sciatic nerves of 32 New Zealand white rabbits were selected to make the regeneration and repair models, the left hind limb nerves as the sham-operation side. Diffusion tensor imaging examination of sciatic nerves were performed at 1 and 3 days, 1, 2, 3, 4, 6 and 8 weeks after operation with 1.5 T MRI. Fractional anisotropy and apparent diffusion coefficient were measured through diffusion tensor tracing reconstruction, and then the pathological examination was performed. RESULTS AND CONCLUSION:Diffusion tensor imaging revealed only the proximal nerve, injured nerve as wel as the middle of the distal nerve at 1 day after traction injury. At 1 week, the nerve of distal portion appeared thinner and shorter fiber bundle. At 2-6 weeks after operation, the fiber bundle was increased and thickened. At 8 weeks after operation, the distal nerve fibers had nearly restored to the level before injury. There was significant difference in the fractional anisotropy value of traction portion and distal portions between traction injury and sham-operation group at 1 day-8 weeks after operation (P<0.05). While there was significant difference in the fractional anisotropy value of proximal traction portion between traction injury and sham-operation group 1 day-1 week after operation (P<0.05). There were no significant differences in the apparent diffusion coefficient values between traction injury and sham-operation group at 1 day-8 weeks after operation. Fal of fractional anisotropy value in the early stage of nerve traction injury was the result of myelin sheath broke down and axonal disintegrated;recovery of fractional anisotropy value resulted from myelin sheath proliferated and myelin sheath grew slowly to mature. Diffusion tensor tracing can show the abnormal change of the sciatic nerve with traction injury in rabbit clearly and early, and the measurement of fractional anisotropy value can be used as the sensitive method to monitor the degeneration and regeneration after nerve traction injury.
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Purpose To investigate the effect of sensitivity on image quality and radiation dosage of digital chest radiography. Materials and Methods A total of 300 healthy people undergoing chest X-ray examination were randomly enrolled and divided into two groups according to body weight (150 people with normal weight and 150 overweight), which were further randomly divided into three subgroups (S200 subgroup with low-sensitivity, S400 subgroup with mid-sensitivity, S800 subgroup with high sensitivity, each subgroup contained 50 people). With other parameters unchanged, digital chest photography with different sensitivities was performed to each subgroup (S200, S400 and S800, respectively), and then uploaded the data to PACS and recorded mAs value and dose area product (DAP) value for each time. Then the image quality was assessed by three doctors in terms of mAs value, DAP, image quality score and noise score. Results In all subgroups of normal weight, differences on mAs and DAP were significant (F=1443.191-1829.895, P0.05). In all overweight subgroups, differences in mAs, DAP, image quality score and noise score were significant (F=163.358-290.656, PS400>S800 (F=0.626-3.210, PS400>S800 (F=0.416-1.416, P0.05). In overweight group, there was no difference between subgroups of S200 and S400 (F=0.120-0.145, P>0.05); whilst differences between subgroups of S200 and S800 were significant, the same appeared in subgroups of S400 and S800 (F=1.655-2.360, P<0.05). Conclusion Radiation dose can be effectively controlled by regulating sensitivity with image quality unaffected. It is advisable to choose high-sensitivity photography for patients with normal weight and low or mid-sensitivity photography for overweight patients.
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Objective To compare the success rate, time of tumor formation and number of tumors in three methods of tumor transplantation, in order to seek an ideal animal model for molecular imaging study. Methods Forty-eight BALB/C-nu/nu nude mice were randomly divided into three groups (each n=16). Tumor tissue mass of 2 mm3 was injected into subcutaneous of nude mice in experiment group. Tumor tissue mass of 1 mm3 was applied in control group 1. Tumor cells suspension liquid was injected into subcutaneous of nude mice in control group 2. The tumor formation rate, the time of tumor formation and the number of tumors were observed. MRI scanning were performed 3-6 weeks after implantation. Results The rate of tumor formation of three groups was 93.75%, 75.00% and 43.75%, respectively. The time of tumor formation was (21.7±2.4), (29.8±2.9) and (34.6±3.9) days, respectively. The rate of solitary nodule implanted tumor was 93.33% in experiment group, higher than that in control group 1 (75.00%) and control group 2 (14.29%). The tumors were hypointense on T1WI and hyperintense on T2WI. Conclusion Transplantation 2 mm3 tumor tissue mass is effective to set up the subcutaneous implanted tumor models with a high success rate of tumor formation, a short time of tumor formation and high rate of solitary tumors, being suitable for the study of molecular imaging. The models can undertake conventional T1WI, T2WI and T2-mapping imaging, and the imaging qualities are good.
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Objective To investigate the relationshp among Gp Ⅱ b/ⅡⅢ a、CD62p in platelet activation mark-er and high-sensitivity C-reactive protein (hs-CRP) in elderly patients with chronic cor pulmonary exacerbation. Methods The subjects were divided into four groups (42 elderly patients with cor pulmonary exacerbation,42 eld-erly patients with cot pulmonary remission,30 cases of healthy elderly subjects and 30 cases of healthy non-elderly subjects) . The expression of Gp Ⅱ b/Ⅲ a and CD62p were measured with tricolor flow cytometry. Hs-CRP levels were measured by nephelometry and turbidimetry in patients and normal controls. Results Compared with cor pul-monary remission group,healthy elderly group and healthy non-elderly group, the levels of Gp Ⅱ b/Ⅲ a, CD62p and hs-CRP increased significantly in patients with chronic cor pulmonary exacerbation ( all P < 0.001 ). Gp Ⅱ b/Ⅲ a and CD62p results of the elderly patients with cot pulmonary remission were higher than those in healthy elderly subjects (P <0.05) and healthy non-elderly subjects (P < 0. 001 ) . The expressions of both Gp Ⅱ b/Ⅲa and CD62p in healthy elderly subjects were statistically higher than that in healthy non-elderly subjects ( P < 0.05 ). There was a positive con'elation between the Gp Ⅱ b/Ⅲ a、CD62p and hs-CRP in elderly patients with chronic cot pulmonary exac-erbation(r =0.59,P<0.01 ; r=0.54,P<0.01 ). Conclusions The platelet in elderly patients with chronic cot pulmonary exacerbation is overactivated,which is correlated with hs-CRP.
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Objective To evaluate the tumor targeting characteristic of the Folate-SPIO-DOX-Micelles by in vitro studies,and to test the feasibility of monitor tumor targeting using it and clinical MRI.Methods The polymeric micelles,Folate-SPIO-DOXO-Micelles were prepared.The in vitro tumor cell targeting efficacy of these folate modified and DOX or SPIO-loaded micelles (Folate-SPIO-DOX-Micelles)was evaluated by observing the cellular uptake of micelles by human hepatic carcinoma cells(Bel 7402 cells) which overexpressed folate surface receptors. Cell suspensions were incubated with Folate-SPIO-DOXO-Micelles for 1 h.Prussian blue staining was performed to show intracellular irons.Flow cytometry was used to further quantify the cellular uptake of the nanoparticles into Bel 7402 cells.MRl was performed to show the signal intensity changes by using T2 WI sequences at a clinical 1.5 T MR system.Results Prussian blue staining showed much more intracellular iron in cells incubated with Folate-SPIO-DOX-Micelles than the cells incubated with the non-targeting SPIO-DOX-Micelles.As revealed by flow cytometry,the mean fluorescence intensity of cells in the folate group and the non-folate group were 117.88 and 46.33,respectively.The T2 signal intensity in MRI of cells treated with the folate targeting micelles decreased significantly (when the concentration of SPIO in cell culture medium was 5,10,20,40,and 80 μg/ml,respectively,T2 signal intensity decreased by -5.02%,-23.58%,-45.89%,-70.34%,and -92.41%,respectively).In contrast,T2 signal intensity did not show obvious decrease for cells treated with the folate-free micelles (when the concentration of SPIO in cell culture medium was at 5,10,20,40,and 80 μg/ml,respectively,T2 signal intensity decreased by -3.77%,-2.16%,-2.18%,-2.74% and -19.77%,respectively).Conclusion The polymeric micelles,Folate-SPIO-DOX-Micelles has good targeting ability to the hepatic carcinoma cells in vitro,and the cell targeting events of the micelles can be monitored by using a clinical MR scanner.