常规CT联合虚拟去钙技术诊断早期股骨头坏死的可行性研究

目的 探讨常规CT联合虚拟去钙技术(VNCa)对早期股骨头坏死(ONFH)诊断的价值.方法 前瞻性搜集2020年9月至2021年4月本院拟诊断为ONFH的患者共58例,排除骨折、骨性关节炎,先天性髋关节发育不良、髋关节置换术后、无MR检查患者30例,经X线检查或CT检查排除ONFH(3、4期)髋关节19个,共纳入28例...

Feasibility Study of Conventional CT Combined with Virtual Non-Calcium Dual-Energy Computed Tomography in the Diagnosis of Early Stage Osteonecrosis of Femoral Head

Objective To explore the value of conventional CT combined with virtual decalcification(VNCa) technology in the diagnosis of early femoral head necrosis. Methods From September 2020 to April 2021, a prospective study of 58 patients with osteonecrosis of the femoral head(ONFH) in our hospital was conducted. Fractures, osteoarthritis, congenital hip dysplasia, and hip replacement were excluded. After 30 patients without MR examination, 19 hip joints with ONFH(stage 3 and 4) were excluded by X-ray examination or CT examination. A total of 37 hip joints in 28 cases were included, and the dual-energy CT and MR image interval of hip joints were obtained.The duration of acquiring CT and MR images should not be exceeded for 5 days.Two independent radiologists who were blinded to MRI results and clinical information made diagnosis by conventional CT images and conventional CT combined with VNCa images. Interobserver agreement for the visual evaluation of VNCa images was calculated with Kappa statistic. MRI was used as the standard reference. Another senior radiologist decided the final diagnosis if there were disagreements.The area of bone marrow edema showed by VNCa and MR was set to 1 point if it was less than the one third area of femoral head and neck, 2 points if it was between one third and two third, and 3 points if it was more than two thirds.Comparedthe two methods with Student’s t test. Results Interobserver agreement was excellent(Kappa=0.87,0.90).The sensitivity, specificity, positive predictive value and negative predictive value of group A and group B in the diagnosis of early stage osteonecrosis of femoral head were 45.0%,94.1%,59.3%,90.0% and 80.0%,88.2%,88.9%,78.9%,respectivel.The sensitivity and positive predictive value of group B were higher than those of group A.The Student’s t test result of BME area shown on VNCa image and MRI indicated that there was no statistical difference between the two examinations.(P= 0.759,higher than 0.05). Conclusion Conventional CT combined with VNCa images can improve the diagnostic performance of CT for early ONFH, and can be used as an alternative when the use of MRI is limited.