COMPARISON OF VASCULAR OPACIFICATION AFTE R BOLUS INJECTION OF IOPAMIDOL-300 AND IOPAMIDOL-370 IN SPIRAL CT OF THE THORAX

Purpose : A retrospective study was performed to assess the role of io dine concentration on the opacification of different vascular compartm ents of the chest with a nonionic contrast agent (lopamidol) during ro utine spiral CT examination. Material and method : 105 injected spiral CTs of the chest were studied. 50 examinations were done with lopamid ol 300 (iodine concentration 300 g/L) (l300). 55 examinations were don e with lopamidol 370 (iodine concentration 370 g/L) (l370). A constant 24- g total iodine dose was delivered with no difference in the injec ted iodine flow rates (respectively 0.6 and 0.55 g/s), images were sco red for opacification success, opacification quality and for artefacts in each vascular, of the chest. Results :There was no statistically s ignificant difference in opacification success or in opacification qua lity, in each chest vascular compartment between the group receiving I 300 and the group receiving l370. Artefact frequencies on the lower pa rt of superior vena cava were however different, 24% and 41.8% respect ively. Conclusion : For a constant injected iodine flow rate, a modera te increase in iodine concentration, with decreased injection volume a nd flow rate, had little or no effect on opacification of the aorta an d the pulmonary artery. The presence of artefacts on the lower part of the superior vena cava would suggest that the use of lower concentrat ion contrast media would be advisable for specific vena cava examinati ons.