Noncontrast-enhanced three-dimensional magnetic resonance aortography of the thorax at 3.0 T using respiratory-compensated T1-weighted k-space segmented gradient-echo imaging with radial data sampling: preliminary study.

摘要

OBJECTIVE: To evaluate the feasibility of a respiratory-compensated three-dimensional (3D) T1-weighted k-space segmented gradient-echo imaging sequence with radial data sampling for noncontrast-enhanced 3D magnetic resonance (MR) aortography of the thorax at 3.0 T. MATERIALS AND METHODS: Twenty-two subjects, including healthy volunteers (n = 6) and patients with suspected diseases of the thoracic aorta (n = 16), underwent noncontrast-enhanced 3D MR aortography at 3.0 T acquired using a navigator- or respiratory-gated 3D T1-weighted k-space segmented gradient-echo imaging sequence with radial data sampling (TR, 4.8 milliseconds; TE, 1.5 milliseconds; flip angle, 20 degrees; spatial resolution 0.66 x 0.76 x 5.6-6.4 mm) in the sagittal oblique imaging plane. ECG gating, fat-suppression, and T2-prepared pulses were employed. The vascular contrast of the thoracic aorta and the contrast ratio between the aorta and the superior vena cava or pulmonary artery were compared between the noncontrast-enhanced 3D MR aortography and transverse two-dimensional (2D) steady-state free precession. Image quality of the noncontrast-enhanced 3D MR aortography was rated on a 4 point scale (1, nondiagnostic, to 4, diagnostic and excellent image quality). RESULTS: The noncontrast-enhanced 3D MR aortography provided vascular contrast of the thoracic aorta comparable to, and contrast ratio between the aorta and superior vena cava higher than, those of 2D steady-state free precession. The mean score of image quality of the noncontrast-enhanced 3D MR aortography was 3.0 (diagnostic with no or few artifact), and some major branch arteries were visualized by this imaging. CONCLUSION: Respiratory-compensated 3D T1-weighted k-space segmented gradient-echo imaging with radial data sampling are feasible for the noncontrast-enhanced 3D MR aortography of the thorax at 3.0 T.