title: High-resolution magnetic resonance angiography in the mouse using a nanoparticle blood-pool contrast agent.
abstract: High-resolution magnetic resonance angiography is already a useful tool for studying mouse models of human disease. Magnetic resonance angiography in the mouse is typically performed using time-of-flight contrast. In this work, a new long-circulating blood-pool contrast agent-a liposomal nanoparticle with surface-conjugated gadolinium (SC-Gd liposomes)-was evaluated for use in mouse neurovascular magnetic resonance angiography. A total of 12 mice were imaged. Scan parameters were optimized for both time-of-flight and SC-Gd contrast. Compared to time-of-flight contrast, SC-Gd liposomes (0.08 mmol/kg) enabled improved small-vessel contrast-to-noise ratio, larger field of view, shorter scan time, and imaging of venous structures. For a limited field of view, time-of-flight and SC-Gd were not significantly different; however, SC-Gd provided better contrast-to-noise ratio when the field of view encompassed the whole brain (P < 0.001) or the whole neurovascular axis (P < 0.001). SC-Gd allowed acquisition of high-resolution magnetic resonance angiography (52 x 52 x 100 micrometer(3) or 0.27 nL), with 123% higher (P < 0.001) contrast-to-noise ratio in comparable scan time ( approximately 45 min). Alternatively, SC-Gd liposomes could be used to acquire high-resolution magnetic resonance angiography (0.27 nL) with 32% higher contrast-to-noise ratio (P < 0.001) in 75% shorter scan time (12 min).
authors.affiliation: Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: Gabriel P
authors.initials: GP
authors.lastname: Howles
authors.forename: Ketan B
authors.initials: KB
authors.lastname: Ghaghada
authors.forename: Yi
authors.initials: Y
authors.lastname: Qi
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Mukundan
authors.forename: G Allan
authors.initials: GA
authors.lastname: Johnson
mesh_terms: D000818:Animals; D002536:Cerebral Arteries / Q000033:anatomy & histology*; D003287:Contrast Media / Q000737:chemistry*; D005682:Gadolinium / Q000737:chemistry; D007089:Image Enhancement / Q000379:methods*; D008081:Liposomes / Q000737:chemistry; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D053758:Nanoparticles / Q000737:chemistry*
chemical_list: D003287:Contrast Media; D008081:Liposomes; D005682:Gadolinium