MR imaging of pulmonary parenchyma with a half-Fourier single-shot turbo spin-echo (HASTE) sequence

Objective: To evaluate the utility of a half-Fourier single-shot turbo spin -echo sequence (HASTE) at depicting lung parenchyma and lung pathology. Met hods and patients: A HASTE sequence was applied to five normal volunteers a nd 20 patients with various pulmonary disorders to depict the lung parenchy ma. Images were acquired with EGG-triggering and breath-holding. In three v olunteers, signal intensity measurements from lung parenchyma were performe d using four sequences: (a) HASTE; (b) conventional spin echo; (c) hat spin echo: and (d) gradient echo. T2 maps were produced using the HASTE acquisi tion. Results: Minimal respiratory or cardiac motion artifacts were observe d. The signal-to-noise ratios from lung parenchyma were 27.8 +/- 5.4, 22.0 +/- 3.0, 15.3 +/- 0.9, and 6.0 +/- 1.9 for HASTE, spin-echo, fast spin-echo , and gradient echo sequences, respectively. The scan time for HASTE was 30 2 ms for each slice. The T2 values in the right lung and the left lung were 61.2 +/- 4.1 and 79.1 +/- 8.9 ms in systole and 92.6 +/- 5.8 and 97.5 +/- 12.2 ms in diastole, respectively (P < 0.05 diastole versus systole). The H ASTE sequence demonstrated clearly various pulmonary disorders, including l ung cancer, hilar lymphadenopathy, metastatic pulmonary nodules as small as 3 mm, pulmonary hemorrhage, pulmonary edema and bronchial wall thickening in bronchiectasis. Conclusion: Our preliminary results indicate that the HA STE sequence provides a practical means for breath-hold MR imaging of lung parenchyma. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.