Advance in osteoporosis screening methods / 中华内分泌代谢杂志

Osteoporosis has become a common chronic disease which seriously endangers the health of the elderly. China is facing high incidence of osteoporosis along with " three low" rates of screening, diagnosis, and treatment, the crux of which lies in the lack of convenient and effective screening methods for osteoporosis. DXA, the gold standard for the diagnosis of osteoporosis, has many setbacks such as expensive, radiation, and low accessibility in community, etc. which limits its application in large scale screening. The community screening methods for osteoporosis recommended by national guidelines are IOF one-minute test, osteoporosis self-assessment tool for Asians(OSTA), fracture risk assessment tool(FRAX ?), and quantitative ultrasound(QUS). In recent years, digital X-ray radiogrammetry(DXR) and opportunistic quantitative computed tomography(QCT)have also shown great potential in osteoporosis screening. This article reviews the application and research progress of the above screening methods, with the aim of improving the screening rate and contributing to the tertiary prevention and control mechanism of " wide awareness, early diagnosis and early treatment" of osteoporosis.

Normal reference and regional variation of spinal bone mineral density under the quantitative CT in Chinese male population / 中华健康管理学杂志

Objective:To investigate the normal reference values of spinal bone mineral density measured by quantitative computed tomography (QCT) and the differences of bone mineral density (BMD) in different regions of in Chinese adult males.Methods:Men who underwent low-dose CT lung scan for cancer screening in regions of Northeast, North, East, South, Central and Southwest of China from January 2018 to December 2019 were selected. And the lumbar vertebrae BMD values in the male subjects were measured by the QCT system (Mindways Software, Inc.). The mean BMD values and their decline rates were calculated at an age interval of 10 years, and the prevalence of osteoporosis was calculated according to the American College of Radiology spine QCT osteoporosis diagnostic criteria.Results:A total of 50 682 males with a mean age of (50.22±12.79) years (ranged 20 to 98 years) were included in this study. The peak BMD of (173.11±28.56) mg/cm 3 in the healthy Chinese adult male population appeared in the age group of 20 to 29 years and then declined with age. Before the age of 70 years, the BMD was relatively higher in males in South China, and it was lower in Central China and Southwest China, and it was intermediate in Northeast, North and East of China, with statistically significant differences. There was no significant differences in BMD in the males in the two age groups of 70 to 79 years and 80 and older among the regions in China. The overall decline rate of spinal BMD in Chinese males under QCT was about 46.92% over the lifetime, and it declined obviouslyin the 40-49 age group. The overall prevalence of osteoporosis in Chinese male population aged 50 years and above was approximately 11.42%, with the highest prevalence in Southwest China and Central China (14.72% and 13.87%, respectively) and the lowest in North China and South China (8.53% and 7.71%, respectively). Conclusions:A reference of lumbar spine BMD values for healthy males in China based on QCT is established. BMD values were highest in South China and Lowest in Central China.

Use of aromatase inhibitors in patients with breast cancer is associated with deterioration of bone microarchitecture and density

ABSTRACT Objective: To evaluate changes in bone density and architecture in postmenopausal women with breast cancer (BC) and use of aromatase inhibitor (AI). Subjects and methods: Thirty-four postmenopausal women with BC, without bone metastasis, renal function impairment and who were not receiving bone-active drugs were selected from a population of 523 outpatients treated for BC. According to the presence of hormonal receptors, HER2 and Ki67, seventeen had positive hormonal receptors and received anastrozole (AI group), and seventeen were triple-negative receptors (non-AI group), previously treated with chemotherapy. Areal bone mineral density (aBMD) and vertebral fracture assessment (VFA) analyses were performed by DXA; vBMD and bone microarchitecture were evaluated by HR-pQCT. Fracture risk was estimated using the FRAX tool. Results: No patient referred previous low-impact fracture, and VFA detected one moderate vertebral fracture in a non-AI patient. AI patients showed lower aBMD and BMD T-scores at the hip and 33% radius and a higher proportion of osteoporosis diagnosis on DXA (47%) vs non-AI (17.6%). AI group had significantly lower values for vBMD at the entire, cortical and trabecular bone compartments, cortical and trabecular thickness and BV/TV. They also had a higher risk for major fractures and for hip fractures estimated by FRAX. Several HR-pQCT parameters evaluated at distal radius and distal tibia were significantly associated with fracture risk. Conclusion: AI is associated with alterations in bone density and microarchitecture of both the cortical and trabecular compartments. These findings explain the overall increase in fracture risk in this specific population.

High-resolution CT pulmonary findings in children with severe asthma

Abstract Objective: To compare quantitative CT parameters between children with severe asthma and healthy subjects, correlating to their clinical features. Methods: We retrospectively analyzed CT data from 19 school-aged children (5-17 years) with severe asthma and 19 control school-aged children with pectus excavatum. The following CT parameters were evaluated: total lung volume (TLV), mean lung density (MLD), CT air trapping index (AT%) (attenuation ≤856 HU), airway wall thickness (AWT), and percentage of airway wall thickness (AWT%). Multi-detector computed tomography (MDCT) data were correlated to the following clinical parameters: forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), forced expiratory flow at 25-75% (FEF 25-75%), FEV1/FVC ratio, sputum and bronchoalveolar lavage analysis, serum IgE levels, and previous hospitalizations due to asthma. Results: Asthma patients presented higher mean values of AT% (23.8 ± 6.7% vs. controls, 9.7 ± 3.2%), AWT (1.46 ± 0.22 mm vs. controls, 0.47 ± −735 ± 28 HU vs. controls, −666 ± 19 HU). Mean AT% was 29.0 ± 4.7% in subjects with previous hospitalization against 19.2 ± 5.0% in those with no prior hospitalization (p < 0.001). AT% presented very strong negative correlations with FVC (r = −0.933, p < 0.001) and FEV1 (r = −0.841, p < 0.001) and a moderate correlation with FEF 25-75% (r = −0.608, p = 0.007). AT% correlation with FEV1/FVC ratio and serum IgE was weak (r = −0.184, p = 0.452, and r = −0.363, p = 0.202) Conclusion: Children with severe asthma present differences in quantitative chest CT scans compared to healthy controls with strong correlations with pulmonary function tests and previous hospitalizations due to asthma.

Quantitative computed tomography-derived abdominal visceral adipose tissue and cardiometabolic risk in a large-scale population / 中华健康管理学杂志

Objective:To investigate the relationship between abdominal visceral adipose tissue (VAT) and cardiometabolic risk (CMR) through quantitative computed tomography (QCT).Methods:The present study included 76226 participants. Abdominal fat areas were measured using the QCT Pro Model 4 system. Cardiometabolic indices were collected, including systolic and diastolic blood pressures, fasting plasma glucose, total cholesterol, triglyceride, and low-density and high-density lipoprotein cholesterols CMR score was the sum of abnormal blood pressure, fasting glucose, triglyceride, and high-density lipoprotein cholesterol. Restricted cubic spline and ordered logistic regression models were applied.Results:The mean age was 50±13 years and the percentage of men was 58.8%. The level of VAT area was higher in men than in women (191.7±77.1 cm 2 vs 116.4±56.2 cm 2, P<0.0001 for all). After adjustment for age, the cardiometabolic indices except high-density lipoprotein cholesterol increased with increasing VAT area. When VAT area was 300 cm 2, age-adjusted odds ratios and 95% confidence intervals of a CMR score ≥ 1 were 14.61 (13.31, 16.04) for men and 5.46 (4.06, 7.36) for women, and the age-adjusted probability of a CMR score ≥ 3 was 31.7% for men and 31.3% for women. Conclusions:QCT-derived VAT is closely related to CMR. The findings suggest that measurement of visceral fat is recommended for the management of abdominal obesity in subjects who agree to undergo lung cancer screening via low-dose CT without additional radiation exposure.

Effect of the location and size of region of interest on the measurement of liver fat content by QCT / 中华健康管理学杂志

Objective:To explore the effect of the location and size of region of interest (ROI) on the measurement of liver fat by means of quantitative computed tomography (QCT).Methods:A total of 98 subjects who were examined with QCT for bone mineral density examination from December 25, 2019 to January 17, 2020 were recruited continuously from the Department of Health Management of Henan Provincial People′s Hospital. The liver fat content was measured by QCT workstation. The ROI was located respectively in the left lobe, the right anterior lobe and the right posterior lobe of the liver, and it was measured independently by the A measurer and B measurer. The central position of the ROI was fixed and the diameter was increased, and it was measured by the A measurer. In this study, Friedman test was used to compare the differences of measurement results in different positions or sizes of ROI, and intra-class correlation coefficients (ICC) was used to evaluate the repeatability of inter-measurers.Results:There was a significant difference for liver fat content under different positions of ROI (χ2=62.306, P<0.001), but no difference under different seizes of ROI (χ2=1.088, P=0.581). The ICC values of the inter-measurers repeatability analysis of the A measurer and B measurer in the left lobe, right anterior lobe and right posterior lobe of the liver were 0.847, 0.917 and 0.874, all more than 0.75, and the reproducibility was good. Conclusions:When QCT technique is applied to the measurement of liver fat content, the location conditions of ROI may affect results, so it is necessary to select multiple ROI in the whole liver for measurement. The inter-measurers repeatability of QCT in different parts of the liver is good.

Guiding significance of lumbar quantitative computed tomography in percutaneous vertebroplasty for osteoporotic vertebral compression fractures / 中国骨伤

OBJECTIVE@#To investigate the guiding significance of lumbar quantitative computed tomography (QCT) in percutaneous vertebroplasty (PKP) for osteoporotic vertebral compression fractures (OVCF).@*METHODS@#The clinical data of 90 patients with OVCF underwent PKP from December 2017 to December 2018 were retrospectively analyzed. There were 24 femalesand66males, withanaverage agedof (74.47±6.60) yearsold. Allpatientswere received QCT examination before surgery, andaccording to the QCT value oflumbarspine, the patientswere dividedinto osteopenia decrease group (80 to 120 g/L, 17 cases, 30 vertebrae), osteoporosis group (40 to 80 g/L, 44 cases, 66 vertebrae) and severe osteoporosis group (<40 g/L, 29 cases, 39 vertebrae). Bone cement was injected into vertebral body, AP and lateral X-rays were done during operation. The diffusion and leakage of bone cement in injured vertebrae of patients with different QCT values were observed. Unilateral approach was used for patients whose bone cement diffused beyond the midline of the vertebral body, otherwise, and bilateral approach was adopted, and guiding significance of QCT in PKP for OVCF was analyzed.@*RESULTS@#In 90 cases of 135 vertebrae, 72 cases of 98 vertebral bone cement diffused beyond the midline, accounting for 72.59%. Unilateral approach was used for the 72 patients whose bone cement diffused beyond the midline of the vertebral body, among them, there were 5 cases with 8 vertebrae in osteopenia group, 40 cases with 55 vertebrae in osteoporosis group and 27 cases with 35 vertebrae in severe osteoporosis group. There was significant difference in the bone cement dispersion between three groups (=41.397, =0.000). Moreover, no bone cement leakage occurred in osteopenia group, 3 cases of 4 vertebrae occurred in osteoporosis group and 2 cases of 3 vertebrae in severe osteoporosis group. However, none of the patients with bone cement leakage caused nerve injury and other symptoms, and there was no significant difference in bone cement leakage between the three groups (=2.242, =0.326).@*CONCLUSION@#According to the QCT examination of lumbar spine, defining the degree of osteoporosis and guiding the puncture method can shorten the operation time, reduce the number of fluoroscopy, and effectively improve the safety of vertebroplasty.

Quantitative computed tomography analysis for stratifying the severity of Coronavirus Disease 2019 / 药物分析学报

To examine the feasibility of using a computer tool for stratifying the severity of Coronavirus Disease 2019 (COVID-19) based on computed tomography (CT) images. We retrospectively examined 44 confirmed COVID-19 cases. All cases were evaluated separately by radiologists (visually) and through an in-house computer software. The degree of lesions was visually scored by the radiologist, as follows, for each of the 5 lung lobes:0, no lesion present;1,<1/3 involvement;2,>1/3 and<2/3 involvement;and 3,>2/3 involvement. Lesion density was assessed based on the proportion of ground-glass opacity (GGO), consolidation and fibrosis of the lesions. The parameters obtained using the computer tool included lung volume (mL), lesion volume (mL), lesion percentage (％), and mean lesion density (HU) of the whole lung, right lung, left lung, and each lobe. The scores obtained by the radiologists and quantitative results generated by the computer software were tested for correlation. A Chi-square test was used to test the consistency of radiologist- and computer-derived lesion percentage in the right/left lung, upper/lower lobe, and each of the 5 lobes. The results showed a strong to moderate correlation between lesion percentage scores obtained by radiologists and the computer software (r ranged from 0.7679 to 0.8373, P < 0.05), and a moderate correlation between the proportion of GGO and mean lesion density (r=-0.5894, P<0.05), and proportion of consolidation and mean lesion density (r=0.6282, P<0.05). Computer-aided quantification showed a statistical significant higher lesion percentage for lower lobes than that assessed by the radiologists (x2 = 8.160, P = 0.004). Our experiments demonstrated that the computer tool could reliably and accurately assess the severity and distribution of pneumonia on CT scans.

Application value of quantitative computed tomography for evaluation of changes in abdominal fat after laparoscopic Roux-en-Y gastric bypass in obese patients / 中华消化外科杂志

Objective@#To evaluate the application value of quantitative computed tomography for evaluation of changes in abdominal fat after laparoscopic Roux-en-Y gastric bypass in obese patients.@*Methods@#The retrospective and descriptive study was conducted. The clinical data of 52 obese patients who underwent laparoscopic Roux-en-Y gastric bypass in the Third Medical Center of Chinese PLA General Hospital from March 2011 to February 2012 were collected. There were 24 males and 28 females, aged (43±9)years, with the range of 23-62 years. All the 52 patients underwent laparoscopic Roux-en-Y gastric bypass. Observation indicators: (1) surgical and postoperative conditions; (2) changes in anthropometric indices; (3) follow-up. Follow-up using outpatient examination was performed to detect complications of patients at 1, 3, 6, 12 months after surgery up to February 2013. Measurement data with normal distribution were represented as Mean±SD, repeated measurement data were analyzed using repeated ANOVA. Count data were represented as absolute numbers.@*Results@#(1) Surgical and postoperative conditions: all the patients underwent laparoscopic Roux-en-Y gastric bypass successfully, without conversion to open surgery. The volume of intraoperative blood loss, operation time, and duration of hospital stay were (25±11)mL, (78±14)minutes, and (11±2)days. (2) Changes in anthropometric indices: the body mass index (BMI), fat mass, free fat mass, total abdominal fat volume (TAFV), total subcutaneous fat volume (TSFV), and total visceral fat volume (TVFV) of all the 52 patients were (31.8±1.8)kg/m2, (39.4±4.1)kg, (50.2±6.0)kg, (11 703±3 899)cm3, (7 418±2 969)cm3, and (4 314±1 692)cm3 before surgery, (28.5±1.4)kg/m2, (33.0±1.1)kg, (49.7±4.6)kg, (11 016±3 713)cm3, (7 044±2 970)cm3, (3 969±1 443)cm3 at 3 months after surgery, (27.1±1.7)kg/m2, (30.2±1.3)kg, (45.4±3.1)kg, (9 406±4 452)cm3, (6 442±3 307)cm3, and (2 964±1 694)cm3 at 6 months after surgery, (24.4±2.4)kg/m2, (32.6±1.1)kg, (48.6±2.7)kg, (7 612±3 029)cm3, (5 623±2 650)cm3, and (1 826±360)cm3 at 12 months after surgery, respectively, there were significant differences in the changes of these indices (F=130.2, 30.3, 4.9, 25.6, 11.9, 16.5, P<0.05). The BMI, fat mass, and TAFV at 3 months after surgery had significant differences compared with those before surgery (P<0.05), but free fat mass, TSFV, and TVFV had no significant difference (P>0.05). The BMI, fat mass, TAFV, and TVFV at 6 months after surgery had significant differences compared with those before surgery (P<0.05), but free fat mass and TSFV had no significant difference (P>0.05). The BMI, fat mass, TAFV, TSFV, and TVFV at 12 months after surgery had significant differences compared with those before surgery (P<0.05), but free fat mass had no significant difference (P>0.05). (3) Follow-up: all the 52 patients have completed the follow-up after surgery and the remission number of obesity was 35. No complications such as anastomotic hemorrhage, obstruction, or anastomotic leakage occured in all the 52 patients.@*Conclusion@#Laparoscopic Roux-en-Y gastric bypass can reduce abdominal visceral fat significantly, while quantitative computed tomography can help to evaluate the distribution of abdominal visceral fat accurately.

Characteristics of abdominal fat distribution in patients with primary aldosteronism / 中华内分泌代谢杂志

Objective To compare the abdominal fat distribution in patients with primary aldosteronism (PA) and essential hypertension (EH), and to analyze the correlation between abdominal fat area and indexes such as glycolipid metabolism and insulin resistance. Methods Forty-five PA and 55 EH patients were collected from inpatients in the First Affiliated Hospital of Zhengzhou University for suspicious secondary hypertension, from September 2016 to February 2019. All patients accepted quantitative computed tomography to measure the total abdominal fat area ( TFA), visceral fat area ( VFA), and subcutaneous fat area ( SFA) when accepted adrenal CT detection. Visceral obesity was defined as VFA≥130 cm2. The percentage of visceral fat area in total abdominal fat area (V%=VFA/TFA), the ratio of visceral fat area to subcutaneous fat area (V/S=VFA/SFA) and the percentage of visceral obesity were calculated. Results TFA and VFA in EH group were higher than those in PA group matched by age, gender, and body mass index (BMI, all P＜0.01), and there were without statistically significant differences in SFA, V%, V/S, and the percentage of visceral obesity between the two groups. In PA group, TFA and VFA were positively correlated with homeostasis model assessment of insulin resistance index ( P＜0. 01), TFA was positively correlated with triglycerides ( TG) and low density lipoprotein-cholesterol, while SFA was positively correlated with TG (all P＜0.05). Conclusion Compared with EH patients matched by age, gender, and BMI, TFA and VFA in PA patients are lower. Abdominal fat area is associated with insulin resistance and blood lipids in PA patients, while VFA exerts a greater effect on insulin resistance than that of TFA and SFA.

Application value of quantitative computed tomography for evaluation of changes in abdominal fat after laparoscopic Roux-en-Y gastric bypass in obese patients / 中华消化外科杂志

Objective To evaluate the application value of quantitative computed tomography for evaluation of changes in abdominal fat after laparoscopic Roux-en-Y gastric bypass in obese patients.Methods The retrospective and descriptive study was conducted.The clinical data of 52 obese patients who underwent laparoscopic Roux-en-Y gastric bypass in the Third Medical Center of Chinese PLA General Hospital from March 2011 to February 2012 were collected.There were 24 males and 28 females,aged (43±9)years,with the range of 23-62 years.All the 52 patients underwent laparoscopic Roux-en-Y gastric bypass.Observation indicators:(1) surgical and postoperative conditions;(2) changes in anthropometric indices;(3) follow-up.Follow-up using outpatient examination was performed to detect complications of patients at 1,3,6,12 months after surgery up to February 2013.Measurement data with normal distribution were represented as Mean±SD,repeated measurement data were analyzed using repeated ANOVA.Count data were represented as absolute numbers.Results (1) Surgical and postoperative conditions:all the patients underwent laparoscopic Roux-en-Y gastric bypass successfully,without conversion to open surgery.The volume of intraoperative blood loss,operation time,and duration of hospital stay were (25± 11) mL,(78± 14) minutes,and (11±2) days.(2) Changes in anthropometric indices:the body mass index (BMI),fat mass,free fat mass,total abdominal fat volume (TAFV),total subcutaneous fat volume (TSFV),and total visceral fat volume (TVFV) of all the 52 patients were (31.8 ± 1.8)kg/m2,(39.4±4.1)kg,(50.2±6.0)kg,(l1 703±3 899)cm3,(7 418±2 969)cm3,and (4 314± 1 692)cm3 before surgery,(28.5±1.4)kg/m2,(33.0±1.1)kg,(49.7±4.6)kg,(11 016±3 713) cm3,(7 044± 2970)cm3,(3969±1 443)cm3 at 3 months after surgery,(27.1±1.7)kg/m2,(30.2±1.3)kg,(45.4± 3.1)kg,(9 406±4 452)cm3,(6 442±3 307)cm3,and (2 964±1 694) cm3 at 6 months after surgery,(24.4± 2.4)kg/m2,(32.6±1.1)kg,(48.6±2.7)kg,(7 612±3 029)cm3,(5 623±2 650)cm3,and (1 826±360) cm3 at 12 months after surgery,respectively,there were significant differences in the changes of these indices (F=130.2,30.3,4.9,25.6,11.9,16.5,P＜0.05).The BMI,fat mass,and TAFV at 3 months after surgery had significant differences compared with those before surgery (P＜0.05),but free fat mass,TSFV,and TVFV had no significant difference (P＞0.05).The BMI,fat mass,TAFV,and TVFV at 6 months after surgery had significant differences compared with those before surgery (P ＜ 0.05),but free fat mass and TSFV had no significant difference (P＞0.05).The BMI,fat mass,TAFV,TSFV,and TVFV at 12 months after surgery had significant differences compared with those before surgery (P＜0.05),but free fat mass had no significant difference (P＞ 0.05).(3) Follow-up:all the 52 patients have completed the follow-up after surgery and the remission number of obesity was 35.No complications such as anastomotic hemorrhage,obstruction,or anastomotic leakage occured in all the 52 patients.Conclusion Laparoscopic Roux-en-Y gastric bypass can reduce abdominal visceral fat significantly,while quantitative computed tomography can help to evaluate the distribution of abdominal visceral fat accurately.

High-resolution Peripheral Quantitative Computed Tomography for the Assessment of Bone Strength and Structure in Obstructive Sleep Apnea Patients / 中国医学科学院学报

To evaluate the bone strength and structure of patients with obstructive sleep apnea(OSA)by the high-resolution peripheral quantitative computed tomography(HR-pQCT)and to explore the relationship between OSA and osteoporosis. Male patients who visited the Sleep Respiratory Center of our hospital from August 2017 to January 2019 were consecutively recruited.Clinical data including the results of Epworth sleep scale(ESS)scoring and overnight polysomnography were collected.HR-pQCT was used to compare the differences in bone geometry,density,and microstructure between OSA patients and non-OSA people;also,the radius and tibia on the non-dominant side were measured to explore the relationship between OSA and osteoporosis. A total of 83 subjects were enrolled in the study.The number of patients in the mild,moderate,and severe OSA groups and non-OSA group were 21,18,34,and 10,respectively.There was no significant difference in age,blood pressure,ESS score,sleep stage,and sleep efficiency among these four groups(>0.05).Body mass index(BMI)and neck circumference were significantly different among these groups(=4.234,=0.008;=3.100,=0.031).There was no significant difference in the radius indicators(>0.05).For tibia,there were significant differences among the four groups in the cortical area(Ct.Ar)(=3.937,=0.011).There were also significant differences in the bone microstructural indicators including trabecular thickness(Tb.Th)and cortical thickness(Ct.Th)(=6.247,=0.001;=3.746,=0.014),which were significantly lower in the three OSA groups than in the control group.Pairwise comparisons showed that the Ct.Ar in the severe OSA group was significantly higher than that in the mild OSA group(=0.019)and Tb.Th in the control group was significantly higher than those in the mild and moderate OSA groups(=0.006,=0.001).Correlation analysis showed that,within a certain range,total volumetric bone mineral density(Tt.vBMD)and Tb.Th of radius and tibia were negatively correlated with age(=-0.312,=0.004;=-0.328,=0.002;=-0.265,=0.015;=-0.280,=0.010)and positively correlated with BMI(=0.240,=0.029;=0.369,=0.004;=0.299,=0.006;=0.416,=0.010).Stepwise multiple regression analysis showed that Tb.Th of radius and tibia were mostly correlated with BMI(=0.262,=0.008,=0.243,=6.270,=0.000;=0.494,=0.000,=0.186,=7.243,=0.000)and age(=-0.216,=0.030,=0.243,=6.270,=0.000;=-0.306,=0.003,=0.186,=7.243,=0.000).Tt.vBMD of radius had a certain correlation with sleep efficiency and with the decreasing nocturnal mean oxygen saturation caused by OSA(=0.312,=0.002, =-0.249,=0.012,=0.327,=7.482,=0.000). In non-elderly male populations,OSA mainly causes a decrease in Tb.Th and Ct.Th of the tibia.The changes in bone strength and structure are mainly related with age and body size and also have certain correlations with sleep efficiency and with the decreasing nocturnal mean oxygen saturation caused by OSA.

Review of high-resolution peripheral quantitative computed tomography for the assessment of bone microstructure and strength / 生物医学工程学杂志

Trabecular microstructure is an important factor in determining bone strength and physiological function. Normal X-ray and computed tomography (CT) cannot accurately reflect the microstructure of trabecular bone. High-resolution peripheral quantitative computed tomography (HR-pQCT) is a new imaging technique in recent years. It can qualitatively and quantitatively measure the three-dimensional microstructure and volume bone mineral density of trabecular bone . It has high precision and relative low dose of radiation. This new imaging tool is helpful for us to understand the trabecular microstructure more deeply. The finite element analysis of HR-pQCT data can be used to predict the bone strength accurately. We can assess the risk of osteoporosis and fracture with three-dimensional reconstructed images and trabecular microstructure parameters. In this review, we summarize the technical flow, data parameters and clinical application of HR-pQCT in order to provide some reference for the popularization and extensive application of HR-pQCT.

Does Simultaneous Computed Tomography and Quantitative Computed Tomography Show Better Prescription Rate than Dual-energy X-ray Absorptiometry for Osteoporotic Hip Fracture? / 대한고관절학회지

PURPOSE: This study aimed to evaluate the efficacy of simultaneous computed tomography (CT) and quantitative CT (QCT) in patients with osteoporotic hip fracture (OHF) by analyzing the osteoporosis detection rate and physician prescription rate in comparison with those of conventional dual-energy X-ray absorptiometry (DXA). MATERIALS AND METHODS: This study included consecutive patients older than 65 years who underwent internal fixation or hip arthroplasty for OHF between February and May 2015. The patients were assigned to either the QCT (47 patients) or DXA group (51 patients). The patients in the QCT group underwent QCT with hip CT, whereas those in the DXA group underwent DXA after surgery, before discharge, or in the outpatient clinic. In both groups, the patients received osteoporosis medication according to their QCT or DXA results. The osteoporosis evaluation rate and prescription rate were determined at discharge, postoperative (PO) day 2, PO day 6, and PO week 12 during an outpatient clinic visit. RESULTS: The osteoporosis evaluation rate at PO week 12 was 70.6% (36 of 51 patients) in the DXA group and 100% in the QCT group (P < 0.01). The prescription rates of osteoporosis medication at discharge were 70.2% and 29.4% (P < 0.001) and the cumulative prescription rates at PO week 12 were 87.2% and 60.8% (P=0.003) in the QCT and DXA groups, respectively. CONCLUSION: Simultaneous CT and QCT significantly increased the evaluation and prescription rates in patients with OHF and may enable appropriate and consistent prescription of osteoporosis medication, which may eventually lead to patients' medication compliance.

CT Quantification of Lungs and Airways in Normal Korean Subjects

OBJECTIVE: To measure and compare the quantitative parameters of the lungs and airways in Korean never-smokers and current or former smokers (“ever-smokers”). MATERIALS AND METHODS: Never-smokers (n = 119) and ever-smokers (n = 45) who had normal spirometry and visually normal chest computed tomography (CT) results were retrospectively enrolled in this study. For quantitative CT analyses, the low attenuation area (LAA) of LAA(I-950), LAA(E-856), CT attenuation value at the 15th percentile, mean lung attenuation (MLA), bronchial wall thickness of inner perimeter of a 10 mm diameter airway (Pi10), total lung capacity (TLC(CT)), and functional residual capacity (FRC(CT)) were calculated based on inspiratory and expiratory CT images. To compare the results between groups according to age, sex, and smoking history, independent t test, one way ANOVA, correlation test, and simple and multiple regression analyses were performed. RESULTS: The values of attenuation parameters and volume on inspiratory and expiratory quantitative computed tomography (QCT) were significantly different between males and females (p < 0.001). The MLA and the 15th percentile value on inspiratory QCT were significantly lower in the ever-smoker group than in the never-smoker group (p < 0.05). On expiratory QCT, all lung attenuation parameters were significantly different according to the age range (p < 0.05). Pi10 in ever-smokers was significantly correlated with forced expiratory volume in 1 second/forced vital capacity (r = −0.455, p = 0.003). In simple and multivariate regression analyses, TLC(CT), FRC(CT), and age showed significant associations with lung attenuation (p < 0.05), and only TLC(CT) was significantly associated with inspiratory Pi10. CONCLUSION: In Korean subjects with normal spirometry and visually normal chest CT, there may be significant differences in QCT parameters according to sex, age, and smoking history.

Clinical application of quantitative computed tomography in osteogenesis imperfecta-suspected cat

One-year-old male Persian cat presented with multiple fractures and no known traumatic history. Marked decrease of bone radiopacity and thin cortices of all long bones were identified on radiography. Tentative diagnosis was osteogenesis imperfecta, a congenital disorder characterized by fragile bone. To determine bone mineral density (BMD), quantitative computed tomography (QCT) was performed. The QCT results revealed a mean trabecular BMD of vertebral bodies of 149.9 ± 86.5 mg/cm³. After bisphosphonate therapy, BMD of the same site increased significantly (218.5 ± 117.1 mg/cm³, p < 0.05). QCT was a useful diagnostic tool to diagnose osteopenia and quantify response to medical treatment.

The correlation and prediction error of anthropometric indicators and quantitative computed tomography in measuring abdominal fat / 重庆医学

Objective To investigate the correlation and standard estimate error of anthropometric indicators and abdominal visceral fat by quantitative computed tomography (QCT) .Methods We measured the height ,weight ,waist circumference(WC) , hip circumference(HC) in 568 Chinese adults (including 234 males and 334 females) .Abdominal adipose tissue was quantitatively measured by tissue composition module of Mindways QCT software using QCT scan data .The total fat area(TFA) and the visceral fat area(VFA) were measured in a slice in the inferior of T12 ,L1 ,L2 ,L3 ,L4 ,L5 vertebra and umbilicus level .The subcutaneous fat area(SFA) ,total abdominal fat volume ,total visceral fat volume(TVFV) and total subcutaneous fat volume(TSFV) were calculated from measurements .Correlations among BMI ,WC ,HC ,WHR and VFA was assessed .Standard estimate error(SEE) of BMI ,WC , HC ,WHR in the prediction of the VFA by QCT was calculated .Results Correlation between WC and VFA in different anatomical locations was better than BMI ,HC and WHR ,the correlation coefficients R2 was 0 .48-0 .64 in male and 0 .53-0 .66 in female ,all P<0 .01 .The SEE of WC in the prediction of the VFA measured by QCT were 25 .36-31 .57 cm2 (male) ,23 .64-25 .31 cm2 (fe‐male) ,or 23 .13% -27 .78% (male) ,25 .44% -36 .03% (female) .Conclusion The standard estimate error of anthropometry pa‐rameters in the prediction of VFA was significant .QCT is a more accurate measurement of VFA ,and it has the potential of clinical application .

The distribution of abdominal and pelvic adipose tissue in malignant gynecologic tumor and benign gynecologic diseas / 重庆医学

Objective To study the abdominal and pelvic adipose tissue volume and distribution in patients with malignant gynecologic tumor and benign gynecologic disease prospectively .Methods Eighty patients with malignant gynecologic tumor and eighty patients with benign gynecologic disease were underwent abdominal and pelvic CT scan by 64‐slice spiral CT and QCT cali‐bration phantom .The area and the volume of TAT ,VAT ,SAT of abdomen and(or) pelvis(TFV ,VFV ,SFV and VFV/SFV) were measured and calculated .The differences between the malignant gynecologic tumor group and the benign gynecologic disease group and between the different stages or types of malignant gynecologic tumor groups were compared ,then the distribution of AT was analyzed .Results (1)Except the VFV of abdomen and pelvis ,there were differences in TFV ,VFV and SFV between the malignant gynecologic tumor group and the benign gynecologic disease group(P0 .05) .There were differences in VFV/SFV between the early‐stage and the benign gynecologic disease group and between the advanced‐stage and the benign gynecologic dis‐ease group(P0 .05) .(3)There was no difference in abdominal and pelvic TFV ,VFV ,SFV ,VFV/SFV between the en‐dometrial carcinoma and the cervical carcinoma group(P>0 .05) .(4)There were positive correlations between abdominal or pelvic VFV ,SFV and abdominal and pelvic TFV ,the abdominal SFV was the highest .Conclusion The patients with malignant gyneco‐logic tumor ,especially in the early‐stage ,were much fatter than the patients with benign gynecologic disease .In malignant gyneco‐logic tumor patients ,the SAT increased more significantly than the VAT ,and had the highest correlation with TAT ,and was the mainly composition of obesity .

Densidad ósea volumétrica vertebral obtenida sin fantoma en estudios de rutina de tomografía computarizada de abdomen: correlación con los valores medidos por densitometría ósea areal por rayos X / Phantom-less volumetric vertebral density obtained from routine abdominal ct studies: correlation with data obtained by DXA

La densidad mineral ósea (DMO) por tomografía computarizada cuantitativa (QCT) mide con exactitud y precisión de corto plazo la densidad volumétrica (DMOv) de secciones axiales de los cuerpos vertebrales lumbares valiéndose de un fantoma de calibración. Existe evidencia de que la densitometría por TC sin fantoma convirtiendo las unidades Hounsfield en g/cm3 aplicando un coeficiente específico para cada equipo, presenta muy alta correlación con la DMO por QCT y que es confiable para evaluar la densidad ósea vertebral. Apoyándonos en ello, correlacionamos DMO y CMO estimados a partir de estudios de TC con los obtenidos por DXA. Se incluyeron 28 mujeres (edad: 63,4±10,3 años, rango: 37-85) que habían realizado una TC de abdomen y previamente una DMO en un lapso previo no mayor de 6 meses. Se midieron: 1) TC: DMOv promedio integral (trabecular + cortical) en un corte axial medio vertebral de 10 mm de espesor y el área en cm2 . Se multiplicó la densidad por el área, obteniendo un valor equivalente al CMO de la sección (CMO-TC) y 2) DXA: se consideraron la DMOa y CMO en una RI de 10 mm de altura a nivel del centro de la vértebra L3. Las correlaciones entre los parámetros homólogos obtenidos por ambos métodos fueron significativas: resultó superior para CMO [DMOv vs. DMOa r: 0,67 (p=0,005) y CMO-TC vs. CMO-DXA r: 0,75 (p=0,00063)]. El estudio complementa los ya existentes y abre la posibilidad de utilizar estudios de rutina de TC de abdomen para evaluar la densidad ósea, para lo cual deberán establecerse valores de referencia sexo y edad específicos. (AU)

Conventional quantitative computed tomography (QCT) uses a calibration phantom scanned simultaneously with the anatomical region of interest and measures bone density accurately and with short-term high precision. Evidence supports that phantom-less volumetric BMD highly correlates with QCT BMD and is a reliable method for assessing bone density of vertebral bodies. Assessment of BMD in routine abdominal CT scans has been investigated in recent years. The aim of the study was to correlate BMD and bone mineral content (BMC) obtained from CT studies with data obtained by DXA. Twenty eight women (age 63.4±10.3 years old, range: 37-85) who underwent abdominal CT for different reasons and DXA measurements within 6 months were included. A simple manual region of interest (RI) which delineated the edge of the vertebral body was applied to L3. We measured 1) CT: Volumetric integral density (BMDv) -trabecular and cortical bone- of the axial section and area (A) in cm2 . Density was multiplied by area to obtain a value equivalent to BMC. 2) DXA: BMD and BMC in a RI of 10 mm height in the middle of L3. All parameters obtained by CT correlated significantly with the corresponding to DXA : BMDv vs BMDa r: 0.67 (p=0.005) y BMC-CT vs BMC-DXA: r: 0.75 (p=0.00063). This study complements previous reports and opens the possibility of using routine abdominal CT studies to assess bone density. For that purpose reference values (age and gender) must be established. (AU)

Tomografia computadorizada quantitativa periférica de alta resolução para avaliação de parâmetros morfológicos e funcionais ósseos / High resolution peripheral quantitative computed tomography for the assessment of morphological and mechanical bone parameters

RESUMOA tomografia computadorizada quantitativa periférica de alta resolução (HR-pQCT) é uma nova tecnologia disponível comercialmente há menos de 10 anos que permite a feitura de exames in vivo para a avaliação de parâmetros ósseos. A HR-pQCT avalia a forma, o número, o volume, a densidade, a conectividade e a separação das trabéculas; a densidade e a espessura do osso cortical e o volume e a densidade total, em alta definição, o que permite a construção digital da microarquitetura óssea adicionalmente. A aplicação de cálculos matemáticos aos dados capturados, método denominado elemento finito (FE), permite a estimativa das propriedades físicas do tecido e simula cargas suportadas de forma não invasiva. Desse modo, a HR-pQCT adquire simultaneamente dados antes fornecidos separadamente pela densitometria óssea, pela ressonância magnética e pela histomorfometria e agrega estimativas biomecânicas antes só possíveis em tecidos extraídos. A reprodutibilidade do método é satisfatória, com coeficientes de variação que raramente ultrapassam os 3%. Quanto à acurácia, os parâmetros apresentam de regular a boa concordância (r2= 0,37-0,97).A principal aplicação clínica é na quantificação e no monitoramento das doenças osteometabólicas, porque avalia de modo mais completo a resistência óssea e o risco de fratura. Na artrite reumatoide permite-se a aferição do número e do tamanho das erosões e dos cistos, além do espaço articular. Na osteoartrite é possível caracterizar as áreas edema-símile que guardam correlação com a degradação da cartilagem.Restritas ainda a um instrumento de pesquisa, dado o seu elevado custo, a alta resolução e a eficiência mostram-se como vantagens em relação aos métodos atualmente usados para a avaliação óssea, com um potencial para tornar-se uma importante ferramenta na prática clínica.

ABSTRACTHigh resolution peripheral quantitative computed tomography (HR-pQCT) is a new technology commercially available for less than 10 years that allows performing in vivo assessment of bone parameters. HR-pQCT assesses the trabecular thickness, trabecular separation, trabecular number and connectivity density and, in addition, cortical bone density and thickness and total bone volume and density in high-definition mode, which additionally allows obtaining digital constructs of bone microarchitecture. The application of mathematics to captured data, a method called finite element analysis (FEA), allows the estimation of the physical properties of the tissue, simulating supported loads in a non-invasive way. Thus, HR-pQCT simultaneously acquires data previously provided separately by dual energy x-ray absorptiometry (DXA), magnetic resonance imaging and histomorphometry, aggregating biomechanical estimates previously only possible in extracted tissues. This method has a satisfactory reproducibility, with coefficients of variation rarely exceeding 3%. Regarding accuracy, the method shows a fair to good agreement (r2 = 0.37-0.97).The main clinical application of this method is in the quantification and monitoring of metabolic bone disorders, more fully evaluating bone strength and fracture risk. In rheumatoid arthritis patients, this allows gauging the number and size of erosions and cysts, in addition to joint space. In osteoarthritis, it is possible to characterize the bone marrow edema-like areas that show a correlation with cartilage breakdown.Given its high cost, HR-pQCT is still a research tool, but the high resolution and efficiency of this method reveal advantages over the methods currently used for bone assessment, with a potential to become an important tool in clinical practice.