ABSTRACT
Objective To investigate the features of intravertebral vacuum phenomenon (IVP)in vertebral compression fractures (VCFs). Methods Two hundred and nine patients with VCFs underwent percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP). The biopsies and the images of X-ray, CT, MRI of VCFs were obtained. The consistency between IVP and osteonecrosis on histology and the positive predictive value (PPV), negative predictive value (NPV), sensitivity, specificity and Youden index of IVP for diagnosing local osteonecrosis in VCFs were analyzed. Fisher exact probability test was used to analyze the coherence between IVP and osteonecrosis. Results Histological examination revealed 146(69.9%) osteoporoses, 10 (4.8%) osteonecroses with osteoporoses, 53 (25.4%) neoplasms. Prior to surgery,10 cases of IVP were found. Plain radiograph showed horizontally oriented lucent cleft in the vertebral body;CT further confirmed the location of gas;T_1-weighted MR image appeared hypointensity,while the signal intensity of T_2-weighted MR image differed, depending on the duration of recumbency. Nine of 10 patients with IVP showed osteonecrosis on histology, while 9 of 10 patients with osteonecrosis contained IVP. The association of osteonecrosis on histology and the IVP was statistically significant(P <0.01). The PPV, NPV, sensitivity, specificity, and Youden index for diagnosing local osteonecrosis was 90% (9/10), 99.5% (198/199), 90.0% (9/10), 99.5% (198/199), and 0.9, respectively. Conclusion The IVP is stongly suggestive of local osteonecrosis in vertebral compression fracture.
ABSTRACT
Objective To investigate the accuracy of 320-slice row CT system for the detection of coronary artery disease(CAD)in high pre-test probability population without heart rate/rhythm control.Methods Thirty patients with a high pre-test probability of CAD underwent 320-slice row CT without preceding heart rate/rhythm control.Invasive coronary angigraphy(ICA)served as the standard reference.Data sets were evaluated by 2 observers in consensus with respect to stenoses≥50% decreased diameter.The sensitivity,specificity,positive predictive value(PPV),negative predictive value(NPV)and Youden index were analyzed;the impact of heart rate and calcification on image quality as well as diagnostic accuracy were also analyzed by Chi-square test Results Mean heart rate during scanning was 73.7±15.4 beats per min(bpm),and median(QR)of Agatston score of segment was 45.6(181).On a per-segment analysis,overall sensitivity was 96.1%(74/77,95%CI:89.03%-99.19%),specificity was 98.3% (337/343,95%CI:96.23%-99.36%),PPV was 92.5% (74/80,95%CI:84.39%-97.20%),NPV of 99.1% (337/340,95%CI:97.44%-99.82%)and the Youden index was 0.94.In both heart-rate subgroups(242 in heart rate＜70 bpm group,169 in heart ratet≥70 bpm group),diagnostic accuracy for the assessment of coronary artery stenosis was similar(P＜0.05).The accuracy and the quality score of the subgroup Agatston score≥100 were lower than that of the subgroup Agatston score＜100;however,the difiercnce of results between 320-slice row CT and ICA was not significant(P＜0.05).Conclusion 320-detector row CT can reliably detect coronary artery stenoses in a high pre-test probability population without heart rate/rhythm control.