MP-RAGE subtraction venography: a new technique.

Preliminary evaluation of a new magnetic resonance (MR) venography technique was performed with data sets from five patients undergoing MR imaging of the brain before and after intravenous administration of gadopentetate dimeglumine. Before contrast agent injection, the patients were imaged with MP-RAGE (magnetization-prepared rapid gradient-echo) and axial turbo T2-weighted sequences. After contrast agent injection, the MP-RAGE sequence was repeated. Images were post-processed with an algorithm that calculates, on a pixel-by-pixel basis, the absolute value of signal intensity of each postcontrast MP-RAGE partition minus that of each precontrast MP-RAGE partition. These subtracted partitions were then subjected to a standard maximum-intensity-projection algorithm to obtain the venogram. In all cases, the new method afforded a high-resolution venogram with clear depiction of venous sinus anatomy. Cortical venous anatomy was also clearly depicted.