| Objective: Using diffusion-weighted MR imaging technology(DWI) to determine quantitatively the diffusion signal intensity values of lumbar vertebral body and apparent diffusion coefficient(ADC) and to study the difference of the values in the different groups of bone density and to analyse the correlation among the DEXA t-scores, diffusion signal intensity value, ADC value, T1 and T2 signal-intensity value, T1 / diffusion signal- intensity values as well as T1/ ADC values, so as to evaluate the value of the diffusion-weighted MR imaging technology(DWI) in the aspect of reflecting the physiological and pathological change of bone marrow of osteoporosis, in order to provide a new idea and method in clinical evaluation about the changes of bone mass of the patients with osteoporosis.Methods: The patients of 80 cases were performed routine MRI examination of Lumbar vertebra, DWI and bone density examination by DXA respectively, according to the test results of DXA and the test results of bone density of lumbar vertebra and femoral neck,the patients were divided into normal, osteopenic and osteoporotic groups respectively, through measuring signal intensity of lumbar vertebral 3 on DWI diagram and ADC diagram we got DWI signal intensity and ADC values. Also, By measuring signal intensity of lumbar vertebral 3 on T1 WI, T2 WI images, we got signal intensity values of T1 and T2.Results: According to the total T score of lumbar measured by DXA, The patients were divided into the normal group: 28 cases(34- 81 years old, average 56.6 ± 12.4 years old); osteopenic group: 29 cases(40- 90 years old, average 58.9 ± 10.1 years old); osteoporotic group: 23 cases(42- 82 years old,average of 62.5 ± 9.1 years old). In accordance with the total T score of the hip femoral neck measured by DXA, the patients were divided into the normal group: 25 cases(34-77 years old, average 53.7 ± 11.4 years old); osteopenic group: 40 cases(37-90 years old, average 60 ± 9.9 years old); osteoporotic group: 15 cases(51-82 years old, average 65.8 ± 8 years old). 1 The differences between groups with different bone density: 1.1 According to the total t-score of lumbar, the normal, osteopenic, osteoporotic groups were divided, the values of the diffusion signal intensity values of lumbar vertebral 3 were 134.5 ± 50.7mm2/s, 112.7 + 37.4 mm2/s, 101.3+24mm2/s,comparing with the values of the normal, osteopenic, osteoporotic groups, there was significant difference among the three groups(P=0.023).By comparing with the values between two groups, there was significant difference between the normal group and osteoporotic group(P=0.009), the values between normal group and osteopenic group showed no significant difference(P=0.06), the values between osteopenic group and osteoporotic group showed no significant difference(P =0.307); The values of ADC of lumbar vertebral 3 were(0.304 ± 0.098) ×10–3 mm2/s,(0.244 ± 0.084) ×10–3 mm2/s,(0.225 ± 0.052) ×10–3 mm2/s, comparing with the values of to the normal, osteopenic,osteoporotic groups, there was significant difference among the three groups(P=0.003), Comparing with the values between two groups, there was significant difference between the normal group and osteopenic group(P=0.009), the values between normal group and osteoporotic group also showed significant difference(P=0.002), the values between osteopenic group and osteoporotic group showed no significant difference(P =0.501). 1.2 In accordance with the total t-score of the femoral neck, the patients were divided into normal, osteopenic and osteoporotic groups, the values of the diffusion signal intensity value of lumbar vertebral 3 were 142.9 ± 51.3 mm2/s, 106.9 ± 33.4 mm2/s, 100.7±17.6 mm2/s, comparing with the values of the normal, osteopenic,osteoporotic groups, there was significant difference among the three groups(P=0.001). By comparing with the values between the two groups, there was significant difference between the normal group and osteopenic group(P=0.001), the values between normal group and osteoporotic group also showed significant difference(P=0.002), the values between osteopenic group and osteoporotic group showed no significant difference(P =0.850); The values of ADC of lumbar vertebral 3 were(0.306 ± 0.093) ×10–3 mm2/s,(0.243 ± 0.087) ×10–3 mm2/s,(0.225 ± 0.042) ×10–3 mm2/s respectivel, comparing with the values of the normal,osteopenic,osteoporotic groups, there was significant difference among the three groups(P=0.003).By comparing with the values between the two groups, there was significant difference between the normal group and osteopenic group(P=0.003), the values between normal group and osteoporotic group also showed significant difference(P=0.003), the values between osteopenic group and osteoporotic group showed no significant difference(P =0.671); 2 The difference between the values of T1 value / diffusion signal intensity values and the T1 value / ADC value among the groups with different bone density: 2.1 According to the total T score of lumbar, three groups of normal, osteopenia, osteoporosis were divided. There was a significant difference(P=0.01) among the three groups by comparing with the values of T1 / diffusion signal intensity of lumbar vertebral 3. By comparing with the values between two groups, there was significant difference between the normal group and osteoporotic group(P=0.003), the values between normal group and osteopenic group showed no significant difference(P=0.079), also, the values between osteopenic group and osteoporotic group still showed no significant difference(P =0.138); There was a significant difference(P=0.003) among the three groups by comparing with the values of T1 value / ADC value of lumbar vertebral 3. By comparing with the values between two groups, there was significant difference between the normal group and osteopenic group(P=0.008), and the values between normal group and osteoporotic group also showed significant difference(P=0.002), the values between osteopenic group and osteoporotic group showed no significant difference(P =0.333). 2.2 In accordance with the total T score of the femoral neck, three groups of normal, osteopenia, osteoporosis were also divided. There was a significant difference(P=0.000) among the three groups by comparing with the values of T1 / diffusion signal intensity. By comparing with the values between two groups, there was significant difference(P=0.000) between the normal group and osteopenic group, the values between normal group and osteoporotic group showed significant difference(P=0.000), and the values between osteopenic group and osteoporotic group also showed significant difference(P =0.031); There was a significant difference(P=0.000) among the three groups by comparing with the values of T1 value / ADC value. By comparing with the values between two groups, there was significant difference(P=0.001) between the normal and osteopenic group, there was significant difference(P=0.000) between the normal group and osteoporotic group, the values between osteopenic group and osteoporotic group showed no significant difference(P =0.234). 3 The correlation between the related indexes of DWI and MRI and DEXA t-scores: 3.1 A positive correlation was showed among the diffusion signal intensity value, ADC value and DEXA t-scores of lumbar vertebral, the correlation coefficients were 0.289(P<0.01), 0.309(P<0.01) respectively. A negative correlation was showed among T1 / diffusion signal intensity values and T1 / ADC value and DEXA t-scores of lumbar vertebral, the correlation coefficients were- 0.346(P<0.01),- 0.333(P<0.01) respectively. There were no correlation was showed among the signal intensity values of T1, T2 and total t-score of lumbar vertebral body. 3.2 A positive correlation was showed among the diffusion signal intensity values, ADC values and femoral neck DEXA t-scores, the correlation coefficients were 0.376(P<0.01), 0.415(P<0.01) respectively. A negative correlation was showed among the signal intensity value of T1, the signal intensity value of T2 and femoral neck DEXA t-scores,the correlation coefficients were- 0.350(P<0.01),- 0.235(P<0.05) respectively. Also, a negative correlation was showed among T1 / diffusion signal intensity values and T1 / ADC values and femoral neck DEXA t-scores, the correlation coefficients were- 0.599(P<0.01),- 0.494(P<0.01)respectively.Conclusions: With decreasing gradually of the DEXA t-scores of normal, osteopenic,osteoporotic groups, both of the DWI signal intensity values and the ADC values of lumbar vertebral 3 measured by diffusion-weighted MR imaging are reduced, by comparing with the diffusion signal intensity values and ADC values, between the two groups, there was significant difference between the normal group and osteopenic group, the values between normal group and osteoporotic group also showed significant difference, the values between osteopenic group and osteoporotic group showed no significant difference,which indicated that due to the fatty marrow content in vertebral body increased gradually and the diffusion movement of cellular water molecules in vertebral body was limited, the physiological and pathological changes in bone marrow of patients with osteoporosis can be understood at the molecular level by using diffusion-weighted MR imaging technology in order to noninvasive conduct the quantitative assessment of osteoporosis. T1 / diffusion signal intensity values may be a reliable index for assessment of osteoporosis. |
PDF Full Text Request