ABSTRACT
The objective of this study was to describe a radiofrequency (RF) coil design for in vivo sodium magnetic resonance imaging (MRI) for use in small animals. Accumulating evidence has indicated the importance and potential of sodium imaging with improved magnet strength (> 7T), faster gradient, better hardware, multi-nucleus imaging methods, and optimal coil design for patient and animal studies. Thus, we developed a saddle-shaped sodium volume coil with a diameter/length of 30/30 mm. To evaluate the efficiency of this coil, bench-level measurement was performed. Unloaded Q value, loaded Q value, and ratio of these two values were estimated to be 352.8, 211.18, and 1.67, respectively. Thereafter, in vivo acquisition of sodium images was performed using normal mice (12 weeks old; n = 5) with a two-dimensional gradient echo sequence and minimized echo time to increase spatial resolution of images. Sodium signal-to-noise ratio in mouse kidneys (renal cortex, medulla, and pelvis) was measured. We successfully acquired sodium MR images of the mouse kidney with high spatial resolution (approximately 0.625 mm) through a combination of sodium-proton coils.
Subject(s)
Animals , Humans , Mice , Kidney , Magnetic Resonance Imaging , Signal-To-Noise Ratio , SodiumABSTRACT
Physiological MR imaging techniques provide abundant information for the diagnosis and research of knee cartilage le -sions.It can not only evaluate the morphology and structure of cartilage , but also analyze the functional , metabolic and biochemical changes quantitatively , to explore the causes of cartilage lesions at the molecular level .Application and advance of physiological MR imaging of knee articular cartilage are reviewed , including sodium imaging , delayed gadolinium enhanced magnetic resonance imaging of cartilage, T1ρ, T2 mapping, chemical exchange saturation transfer , diffusion imaging and so on, aiming at providing references for choosing MR imaging of knee articular cartilage .