[en] Contrast-enhanced 3-D ultrafast MR angiography is a widely accepted MR imaging technique for the evaluation of the carotid artery, aorta, renal artery, mesenteric artery and portal venous system. To estimate its clinical usefulness, single- and double- dose contrast-enhanced 3-D ultrafast pulmonary MR angiography was assessed after a timing examination was performed. Twenty volunteers underwent gadolinium-enhanced ultrafast pulmonary MR angiography (3-D FISP, TR[msec]/TE[msec] = 5.0/2.0, with 25 deg flip angel). In ten volunteers(single-dose injection group) pulmonary MR angiography was performed after the administration of 0.1 mmol/kg(single dose injection group), while the other ten(double-dose injection group) each received, prior to angiography, 0.2 mmol/kg. In all cases, a timing examination was performed during axial turbo-FLASH imaging(TR/TE/TI 8.5/4.0/100, 10 deg flip angle) after injection of the same dose as that used for subsequent contrast-enhanced pulmonary MR angiography. In both groups, overall image quality, pulmonary artery visibility and contrast-to-noise ratio of the pulmonary artery were assessed on the basis of images obtained. With regard to overall image quality, there was no significant statistical difference between the two groups (P>0.05), and in both, depiction of the central and lobar pulmonary artery was excellent. As regards depiction of the segmental artery, the average grading of the single dose injection group was 2.83 ± 0.32, that of the double dose injection group was 2.85 ± 0.3, with no statistical significance (P>0.05). With respect to contrast-to-noise ratio of the central, lobar, and segmental arteries, the best results were obtained by the double dose injection group(P<0.05). Although the contrast-to-noise ratio in the double-dose injection group was better than that in the single-dose group, differences in overall image quality and pulmonary artery depiction were not statistically significant. Thus, single-dose, contrast-enhanced 3-D ultrafast pulmonary MR angiography can provide useful images in clinical trials