In vivo absolute quantification for mouse muscle metabolites using an inductively coupled synthetic signal injection method and newly developed (1) H/(31) P dual tuned probe.
OBJECTIVE
To obtain robust estimates of (31) P metabolite content in mouse skeletal muscles using our recently developed MR absolute quantification method and a custom-built (1) H/(31) P dual tuned radiofrequency (RF) coil optimized for mouse leg.


METHODS
We designed and fabricated a probe consisting of two dual tuned (1) H/(31) P solenoid coils: one leg was inserted to each solenoid. The mouse leg volume coil was incorporated with injector coils for MR absolute quantification. The absolute quantification method uses a synthetic reference signal injection approach and solves several challenges in MR absolute quantification including changes of coil loading and receiver gains.


RESULTS
The (1) H/(31) P dual tuned probe was composed of two separate solenoid coils, one for each leg, to increase coil filling factors and signal-to-noise ratio. Each solenoid was equipped with a second coil to allow injection of reference signals. (31) P metabolite concentrations determined for normal mice were well within the expected range reported in the literature.


CONCLUSIONS
We developed an RF probe and an absolute quantification approach adapted for mouse skeletal muscle.
Department of Radiology, University of Washington, Seattle, Washington, USA.
Donghoon
D
Lee
Kenneth
K
Marro
Mark
M
Mathis
Eric
E
Shankland
Cecil
C
Hayes
D000818:Animals; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006614:Hindlimb; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation* / Q000379:methods*; D008280:Magnetics / Q000295:instrumentation*; D051379:Mice; D008810:Mice, Inbred C57BL; D057054:Molecular Imaging / Q000295:instrumentation*; D018482:Muscle, Skeletal / Q000378:metabolism*; D010759:Phosphorus Isotopes / Q000493:pharmacokinetics*; D011522:Protons; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers
D010759:Phosphorus Isotopes; D011522:Protons
31P metabolites; absolute quantification; dual tuned RF coil; inductive coupling; mouse muscle; signal injection method