Contrast-enhanced, ultrafast 3D pulmonary MR angiography in a single breath-hold: Initial assessment of imaging performance

An ultrafast three-dimensional (3D) sequence was developed, enabling the acquisition of 44 contiguous 2.0- to 2.2-mm thin sections, during intravenous application of paramagnetic contrast, in a single breath-hold. To estimate the potential clinical usefulness, images were assessed qualitatively and quantitatively with regard to visibility of main, lobar, segmental, and subsegmental pulmonary arteries. Five volunteers were examined using a 192 x 192 matrix with an imaging time of 23 seconds and five other volunteers with a 160 x 160 matrix (18 seconds). Each volunteer was imaged in apnea and during shallow respiration. The breath-held 23-second scans revealed excellent image quality and near complete visualization of central and segmental, as well as 81% of subsegmental, pulmonary arteries. Imaging time can be shortened to 18 seconds with only marginal loss in visualization performance (P < .05). Respiratory motion was found to cause significant worsening of image quality and vessel detectability. To maintain relevance in a clinical setting, imaging time can be minimized at the cost of a reduction in spatial resolution.