Helical CT phlebography of the superior vena cava: Diagnosis and evaluation of venous obstruction

OBJECTIVE. The purpose of this study was to determine the feasibility of he lical CT phlebography of the superior vena cava (SVC) and to evaluate the r ole of this imaging technique in the diagnosis and treatment of SVC obstruc tion. SUBJECTS AND METHODS. Twenty-three helical CT phlebograms were obtained of patients with clinical findings that were suggestive of SVC obstruction (n = 19) and of patients undergoing posttherapeutic evaluation for SVC obstruc tion (n = 4). CT examinations consisted of helical acquisitions obtained in the craniocaudal direction with simultaneous bilateral antecubital vein in jection of 2 x 90 mi of 12% iodinated contrast material at 2 ml/sec. Combin ed analysis of axial, multiplanar, and maximum-intensity-projection reforma tted images was used for all patients. Image quality, venous stenosis or ob struction, intraluminal thrombus, and collateral pathways were evaluated. C omparison with digital phlebographic data was available for 16 patients; th is comparison was performed in a nonblinded manner. RESULTS. CT phlebograms were considered technically optimal in 91% of the p atients. In all these patients, helical CT phlebograms showed the venous ob struction: the site, extent, cause, and collateral pathways. CT phlebograph y appeared to be well correlated with digital phlebography in 16 patients r egarding the degree of obstruction, the presence of collateral pathways, an d the presence of thrombus. CONCLUSION. Helical CT phlebography may be a useful technique for imaging t he SVC and its tributaries. This imaging technique is simple to perform and can provide all the information necessary to diagnose and treat SVC obstru ction.