[Basic experimental study of intraosseous venography using carbon dioxide contrast agent in percutaneous vertebroplasty].

PURPOSE In percutaneous vertebroplasty (PVP), intraosseous venography is performed using water-soluble ionic iodinated contrast media (iodine contrast media) before injecting bone cement. However, because of contrast medium remaining in the fractured cleft, we experienced the persistence of intravertebral opacification that obscured visualization of the cement under X-ray fluoroscopy. To solve this problem, we examined carbon dioxide (CO(2)) as a contrast medium. METHODS We measured the contrast of iodine contrast media and CO(2) and performed a subjective assessment of imaging by enforcing intraosseous venography by changing the tube voltage and image intensifier (I.I.) entrance dose in a bone sample of a cadaver using iodine contrast media and CO(2). In vivo study, we performed a subjective assessment of images obtained by intraosseous venography using CO(2) under two kinds of X-ray views. RESULTS We determined that the contrast of CO(2) is 1/6-1/7.5 that of iodine contrast media, and that CO(2) fluctuates less in its contrast value with changes in tube voltage. In our assessment of the image of the bone sample, CO(2) performed worse that iodine contrast media. However, if the I.I. entrance dose is kept above 2.5 microGy/F, CO(2) is considered to be of clinical use. In the clinical image assessment, the best conditions were an image collection rate of 7.5 F/S and matrix of 1024 x 1024. CONCLUSIONS CO(2) did not cause any obstacles when we injected bone cement, and its I.I. entrance dose, image collection rate, and matrix size indicate that it can be used for intraosseous venography.