Proton and sodium MRI assessment of fluid level in calf tissue.
OBJECTIVE
To investigate the feasibility of using (1)H and (23)Na MRI to detect fluid levels in the lower leg muscle.


METHODS
Proton and sodium MRI was applied to detect body fluid levels in the lower leg muscles of 18 healthy young male subjects at 3T and 4T. The paradigms under investigation were a postural change from sitting upright to lying supine, and saline infusion.


RESULTS
We found that the average proton MR signal in gastrocnemius and soleus muscles were reduced following the postural change by 3.5% +/- 1.4% (P < 0.05) and rose following saline infusion by 3.7% +/- 0.9% (P < 0.01). More dramatically, the sodium MR signal decreased by 7.1% +/- 1.2% (P < 0.01) following the postural change and increased following saline infusion by 12% +/- 3.8% (P < 0.05). The ratio of intra- to extracellular fluid levels was 1.6 +/- 0.5 for the subjects based on the acquired proton and sodium data.


CONCLUSIONS
Our results indicate that proton and sodium MRI can be used to assess fluid levels in the lower extremities, and this technique may be applied to evaluate fluid retention.
Zuo
Chun S
CS
Brain Imaging Center, McLean Hospital, Harvard Medical School, Belmont, Massachusetts, USA. chun@mclean.harvard.edu
Villafuerte
Rosemond A
RA
Henry
Michael E
ME
Butman
Michelle
M
Dobbins
Robert L
RL
He
Yiwu
Y
Orban
Barbara S
BS
Cayetano
Kenroy
K
Wang
Liqun
L
Brown
Andrew P
AP
Nunez
Derek J
DJ
Brown
John
J
Renshaw
Perry F
PF
D000293:Adolescent; D000328:Adult; D001826:Body Fluids; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D018482:Muscle, Skeletal / Q000473:pathology*; D009132:Muscles / Q000378:metabolism*; D011522:Protons; D012964:Sodium / Q000494:pharmacology*
D011522:Protons; D012964:Sodium