[Pulmonary hilar diagnosis: comparison of conventional CT and spiral CT]

The aim of the present study was to compare the diagnostic value of spiral CT with that of conventional CT in hilar pathologies. Initially, we determined the minimum amount of contrast material necessary which still produced a good enhancement of the pulmonary vessels. After testing with 20 patients, we found that a bolus of 60 ml injected at a rate of 6 ml/s was optimal. This was then used for 30 patients who were subsequently examined with both CT techniques. In nearly every case, the spiral CT examination produced a significantly better enhancement of the pulmonary vessels than conventional CT. In 35 patients the diagnostic value of the spiral CT was compared with the conventional method. In 19 cases (54%) its diagnostic value was higher, and for 7 of these (20%), an optimal diagnosis was made with spiral CT whereas no clear diagnosis was possible with conventional CT.