Pulmonary vasculature: high-resolution MR imaging. Work in progress.

High-resolution magnetic resonance (MR) imaging of the lung has the potential to depict not only small pulmonary vascular structures but also pulmonary blood flow. Five healthy volunteers were examined to assess the effects of (a) the use of two 5-inch surface coils located on the anterior and posterior chest walls, with a 24-cm field of view and a matrix of 256 X 256; (b) spin-echo acquisition with electrocardiographic (ECG) gating during systole or diastole; and (c) gradient recalled acquisition in a steady state (GRASS) with breath holding. These techniques yielded images showing small peripheral pulmonary vascular structures. Most subsegmental vessels and sixth- and seventh-order branches could be traced, especially near the coils. GRASS images obtained with dual surface coils and breath holding depicted fifth- and sixth-order branches. Preliminary results indicated that small pulmonary vessels can be imaged with MR with a combination of high-resolution techniques and ECG gating in diastole. The sensitivity and reproducibility of these techniques in demonstrating pulmonary vasculature warrant further investigation.