title: Gadomer-17-enhanced 3D navigator-echo MR angiography of the pulmonary arteries in pigs.
abstract: The goal of this study was visualisation and quality assessment of the pulmonary arteries in pigs with modified navigator-echo magnetic resonance angiography using an intravascular contrast agent. Five sedated pigs were examined in a clinical 1.5-T system with modified three-dimensional navigator-echo magnetic resonance angiography (slice thickness 3 mm, pixel size 2.4x1.8 mm2) to evaluate the pulmonary arteries. Using a phased-array four-element thorax coil the entire thorax was scanned before and after intravenous infusion of a gadolinium-based intravascular contrast agent. Assessment of image quality, enhancement-related contrast-to-noise ratio (CNR) measurements and improvement of visibility of peripheral pulmonary vessels was performed. Improvement of quality using Gadomer-17 was found for smaller vessels; pulmonary trunks and the main pulmonary arteries were sufficiently imaged without enhancement. Mean rise of CNR measured in the pulmonary trunks was 28.64% ( P=0.0002), mean rise of CNR in the main pulmonary arteries and the segmental arteries were 79.6% and 148.2%, respectively. Mean distance between the visible peripheral end of 60 sub-segmental arteries and the inner thoracic wall was 12.2 +/- 0.4 mm, and was significantly ( P=0.00002) reduced after contrast infusion to 8.0 +/- 0.4 mm. The combination of inherent flow sensitivity of navigator-echo angiography and Gadomer-17 proved effective for imaging of the pulmonary arteries. In contrast to standard contrast-enhanced pulmonary MRA studies, breath holding is not required. Further studies and the evaluation of findings of patients suffering from pulmonary embolism are needed to evaluate the possible benefits of a higher spatial resolution which is achievable using navigator-echo techniques in contrast to the higher temporal resolution of ultra-fast pulmonary MRA.
authors.affiliation: Institute for Diagnostic and Interventional Radiology, Johann Wolfgang Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany. Abolmaali@em.uni-frankfurt.de
authors.forename: Nasreddin D
authors.initials: ND
authors.lastname: Abolmaali
authors.forename: Volker
authors.initials: V
authors.lastname: Hietschold
authors.forename: Steffen
authors.initials: S
authors.lastname: Appold
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Ebert
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Vogl
mesh_terms: D000818:Animals; D003287:Contrast Media; D005260:Female; D005682:Gadolinium; D007089:Image Enhancement / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D011651:Pulmonary Artery / Q000473:pathology*; D011655:Pulmonary Embolism / Q000175:diagnosis; D013552:Swine
chemical_list: D003287:Contrast Media; C402765:gadomer 17; D005682:Gadolinium