Cine magnetic resonance microscopy of the rat heart using cardiorespiratory-synchronous projection reconstruction.
OBJECTIVE
To tailor a cardiac magnetic resonance (MR) microscopy technique for the rat that combines improvements in pulse sequence design and physiologic control to acquire high-resolution images of cardiac structure and function.


METHODS
Projection reconstruction (PR) was compared to conventional Cartesian techniques in point-spread function simulations and experimental studies to evaluate its artifact sensitivity. Female Sprague-Dawley rats were imaged at 2.0 T using PR with direct encoding of the free induction decay. Specialized physiologic support and monitoring equipment ensured consistency of biological motion and permitted synchronization of imaging with the cardiac and respiratory cycles.


RESULTS
The reduced artifact sensitivity of PR offered improved delineation of cardiac and pulmonary structures. Ventilatory synchronization further increased the signal-to-noise ratio by reducing inter-view variability. High-quality short-axis and long-axis cine images of the rat heart were acquired with 10-msec temporal resolution and microscopic spatial resolution down to 175 microm x 175 microm x 1 mm.


CONCLUSIONS
Integrating careful biological control with an optimized pulse sequence significantly limits both the source and impact of image artifacts. This work represents a novel integration of techniques designed to support measurement of cardiac morphology and function in rodent models of cardiovascular disease.
Brau
Anja C S
AC
Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC 27710, USA. Anja.Brau@med.ge.com
Hedlund
Laurence W
LW
Johnson
G Allan
GA
D000818:Animals; D016477:Artifacts; D005260:Female; D007091:Image Processing, Computer-Assisted / Q000379:methods; D019028:Magnetic Resonance Imaging, Cine; D008853:Microscopy; D009200:Myocardial Contraction; D051381:Rats; D017207:Rats, Sprague-Dawley; D012119:Respiration