Thoracic aorta: Comparison of single-dose breath-hold and double-dose non-breath-hold gadolinium-enhanced three-dimensional MR angiography

OBJECTIVE. The purpose of this study was to compare single-dose (0.1 mmol/k g) breath-hold gadolinium-enhanced three-dimensional (3D) MR angiography an d double-dose (0.2 mmoI/kg) non-breath-hold 3D MR angiography for evaluatio n of thoracic aortic disease. MATERIALS AND METHODS, Twenty-five patients referred for MR evaluation of t he thoracic aorta underwent non-breath-hold gadolinium-enhanced 3D MR angio graphy on a 1.5-T scanner with standard gradients (TR/TE, 21/6; flip angle, 30 degrees) during slow infusion of a double dose of gadopentetate dimeglu mine using a body coil. Subsequently, the same patients underwent breath-ho ld MR imaging with high-performance gradients (TR/TE, 5/2; flip angle, 30 d egrees-50 degrees), a timing examination, and power injection of a single d ose of gadolinium. For both studies, quantitative signal-to-noise measureme nts were obtained for the ascending thoracic, descending thoracic, and abdo minal aorta. Three observers retrospectively evaluated each examination for degree of enhancement of the aorta, pulmonary arteries, and systemic veins ; motion artifacts; and overall image quality. RESULTS. Single-dose breath-hold gadolinium-enhanced 3D MR angiography show ed greater signal-to-noise ratio, fewer motion artifacts, and better overal l image quality (p <.05) than the non-breath-hold double-dose technique. Th e single-dose technique also showed significantly better qualitative enhanc ement of the aortic root and ascending aorta (p <.05) and less enhancement of the pulmonary arteries, renal veins, and left internal jugular vein (p < .05). CONCLUSION. Optimized single-dose breath-hold gadolinium-enhanced 3D MR ang iography is superior to double-dose non-breath-hold 3D MR angiography for e valuation of thoracic aortic disease.