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/kg) breath-hold gadolinium-enhanced three-dimensional (3D) MR angiography and double-dose (0.2 mmoI/kg) non-breath-hold 3D MR angiography for evaluation of thoracic aortic disease. MATERIALS AND METHODS, Twenty-five patients referred for MR evaluation of the thoracic aorta underwent non-breath-hold gadolinium-enhanced 3D MR angiography 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 dimeglumine using a body coil. Subsequently, the same patients underwent breath-hold MR imaging with high-performance gradients (TR/TE, 5/2; flip angle, 30 degrees-50 degrees), a timing examination, and power injection of a single dose of gadolinium. For both studies, quantitative signal-to-noise measurements were obtained for the ascending thoracic, descending thoracic, and abdominal 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 showed greater signal-to-noise ratio, fewer motion artifacts, and better overall image quality (p <.05) than the non-breath-hold double-dose technique. The single-dose technique also showed significantly better qualitative enhancement 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 angiography is superior to double-dose non-breath-hold 3D MR angiography for evaluation of thoracic aortic disease.