Correlation Between CT Values Of Lumbosacral Vertebrae,Paraspinal Muscles And BMD In Postmenopausal Women

Part I.Relationship between CT values and BMD of the lumbosacral vertebral bodies in postmenopausal womenPurpose:By comparing the CT values of the lumbosacral vertebral bodies with those of dual energy X-ray absorptiometry(DXA),we analyzed the relationship between the CT values of the lumbosacral vertebral bodies and BMD,as well as vertebral fractures,in postmenopausal women.Materials and Methods:Divided into 2 sample studies,all patients underwent lumbar spine CT and DXA within 1 week of admission.Sample 1: 95 postmenopausal female patients,ranging in age from 59 to 96 years,with a mean(76.45±10.88 years)and were divided into 3 groups based on bone mineral density(total T-score value): 36 patients in the osteoporotic group,21 patients in the osteopenic group,and 38 patients in the normal bone mass group.The CT values from L2 to S1 vertebral body of the 3 groups of patients were done analysis of variance to measure the CT value of each vertebral body and the total T-score value measured by DXA,correlation analysis was done and the threshold judgment of osteoporosis cut-off value was performed by ROC curve.Sample 2: a total of 116 postmenopausal female patients,aged 57 to 99 years,with a mean(87.03±7.99 years)and were divided into 2 groups based on the presence or absence of lumbar spine fractures: 58 patients in the fracture group and 58 patients in the control group.Independent sample t-test analysis was performed on CT values of vertebral bodies L2 to S1 in the 2 groups.Results:Sample 1: CT values of vertebral bodies L2 to S1 in the osteopenia group(73.02±30.85 HU to 129.07±54.48 HU),CT values of vertebral bodies L2 to S1 in the osteoporotic group(45.5 3±40.02 HU to 98.33±52.47 HU)were both lower than the CT values of vertebral bodies L2 to S1 in the osteonormal group(102.64±58.09 HU to 178.18±83.67 HU,f-value from 11.37 to 16.04,p < 0.01).There was a significant positive correlation between L2 to S1 vertebral body CT values and total T-score values measured by DXA(r-values 0.600 to 0.642,p < 0.01).ROC curve analysis of CT values from L2 to S1 vertebra because the area under the curve of CT values of L2 and L5 vertebrae was the largest(area = 0.750)and the correlation coefficient was the largest(r = 0.642),the diagnostic accuracy of osteoporosis was better at L2 vertebra.In this paper,the L2 vertebral body CT value of 72.25 HU was used as the threshold criterion,which can suggest that postmenopausal female patients have reduced bone mass or osteoporosis.Sample 2: compared with patients without fracture(91.25 ± 27.83 HU to 163.41 ± 49.77 HU)compared to fracture patients with CT values from L2 to S1 vertebrae(41.33±40.20 HU to 59.98±48.06HU)were significantly lower(t-values-8.050 to-5.192,P < 0.01).Therefore,the occurrence of a vertebral fracture was estimated if the CT of the vertebral body was found to be significantly low.Conclusion:Measurement of the L2 to S1 vertebral body CT by a radiologist,who examines the lumbar spine of postmenopausal women,is clinically meaningful for screening for osteoporosis,estimating the occurrence of fractures,detecting osteoporosis in advance,improving patient outcomes,and saving patient expenses.Part II.Association between paraspinal muscle area and BMD of the lumbosacral spine in postmenopausal womenPurpose:To investigate the correlation between the area of paraspinal muscles and bone mineral density of the lumbar spine in routine lumbar spine CT,as well as the correlation with osteoporotic vertebral fractures.Materials and Methods:120 postmenopausal female patients,ranging in age from 59 to 96 years,had a mean(70.7±8.1 years)who underwent routine lumbar CT and were divided into 2groups based on the presence or absence of lumbar spine fractures: 60 patients in the fracture group and 60 patients in the control group.DXA was used to measure bone mineral density(total T-score value)in the 2 groups,while routine lumbar CT was used to measure the cross-sectional area(CSA)of the psoas and erector spinae at the L2 and L4/5 levels and the psoas / erector spinae CSA ratio in the same patients,respectively,with independent samples t-test analysis.Correlation analysis was performed to calculate the correlation between the total T-score values and the psoas CSA,erector spinae CSA,and the psoas / erector spinae CSA ratio at the L2 and L4/5 levels in 120 patients.Results:Bone mineral density of patients in the fracture group(total T-score value =-4.23 ± 0.47 points)was significantly lower than that of control patients(total T-score value =-1.53 ± 0.63,t = 2.67,p < 0.01).There were no significant differences in the CSA of the psoas and erector spinae between the fracture group patients and the control group patients,nor in the psoas / erector spinae CSA ratio(t-values from 0.31 to 1.27,p > 0.05).Correlation analysis showed that the psoas /erector spinae CSA ratio at the L4/5 level in 120 patients(0.60 ±0.19)and bone mineral density(total T-score value =-2.88± 0.54)was correlated(r = 0.21,p <0.05).Conclusion:Paraspinal muscle area can be assessed in routine lumbar CT without additional cost.Although paraspinal muscle area was not associated with lumbar fracture status,there was a correlation between the psoas / erector spinae CSA ratio and lumbar spine BMD at the L4/5 level.