title: Ultra-fast and accurate assessment of cardiac function in rats using accelerated MRI at 9.4 Tesla.
abstract: MRI can accurately and reproducibly assess cardiac function in rodents but requires relatively long imaging times. Therefore, parallel imaging techniques using a 4-element RF-coil array and MR sequences for cardiac MRI in rats were implemented at ultra-high magnetic fields (9.4 Tesla [T]). The hypothesis that these developments would result in a major reduction in imaging time without loss of accuracy was tested on female Wistar rats under isoflurane anesthesia. High-resolution, contiguous short-axis slices (thickness 1.5 mm) were acquired covering the entire heart. Two interleaved data sets (i) with the volume coil (eight averages) and (ii) with the four-element coil array (one average) were obtained. In addition, two-, three-, and fourfold accelerated data sets were generated through postprocessing of the coil array data, followed by a TGRAPPA reconstruction, resulting in five data sets per rat (in-plane voxel size 100 x 100 microm). Using a single blinded operator, excellent agreement was obtained between volume coil (acquisition time: 88 min) and the fourfold accelerated (<3 min) data sets (e.g., LV mass 436 +/- 21 mg vs 433 +/- 19 mg; ejection fraction 74 +/- 5% vs 75 +/- 4%). This finding demonstrates that it is possible to complete a rat cine-MRI study under 3 min with low variability and without losing temporal or spatial resolution, making high throughput screening programs feasible.
authors.affiliation: Department of Cardiovascular Medicine, University of Oxford, United Kingdom. jurgen.schneider@cardiov.ox.ac.uk
authors.forename: Jürgen E
authors.initials: JE
authors.lastname: Schneider
authors.forename: Titus
authors.initials: T
authors.lastname: Lanz
authors.forename: Hannah
authors.initials: H
authors.lastname: Barnes
authors.forename: Debra
authors.initials: D
authors.lastname: Medway
authors.forename: Lee-Anne
authors.initials: LA
authors.lastname: Stork
authors.forename: Craig A
authors.initials: CA
authors.lastname: Lygate
authors.forename: Sean
authors.initials: S
authors.lastname: Smart
authors.forename: Mark A
authors.initials: MA
authors.lastname: Griswold
authors.forename: Stefan
authors.initials: S
authors.lastname: Neubauer
mesh_terms: D000818:Animals; D004867:Equipment Design; D005260:Female; D006321:Heart / Q000502:physiology*; D007091:Image Processing, Computer-Assisted; D019028:Magnetic Resonance Imaging, Cine / Q000295:instrumentation / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar