CONTRAST-ENHANCED MAGNETIC-RESONANCE ANGIOGRAPHY OF THE PULMONARY VASCULATURE - A REVIEW

Magnetic resonance angiography (MRA) has been established as a powerfu l noninvasive imaging modality, Its applications to the study of the p ulmonary vasculature have been hampered by a multitude of factors, suc h as respiratory and cardiac motion artifacts, saturation problems, lo ng acquisition times, and limited spatial resolution, The recent intro duction of contrast-enhanced MRA (CE-MRA) has greatly improved the pot ential for possible investigation of the pulmonary arteries under clin ical conditions. Three-dimensional sequences with minimum TR and TE, a hip angle between 20 degrees and 60 degrees, and minimum slice thickn ess can he considered an optimal approach for breath-hold imaging comb ined with the automatic injection of contrast medium, Early studies ha ve demonstrated the superiority of CE-MRA over nonenhanced techniques. The major indication for CE-MR4 of the pulmonary vasculature is pulmo nary embolism, Here a sensitivity of 85% and specificity of 95% can be obtained. It can be complemented by perfusion imaging, ventilation im aging, functional measurements of the right ventricle, and MR venograp hy of the pelvic and Femoral veins. Blood pool contrast agents will op en new perspectives in the future. This at-title reviews the technical aspects of CE-MRA of the pulmonary vasculature, pathologic findings, and their interpretation as well as present and future clinical applic ations.