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T 1 measurements of 31 P metabolites in resting and exercising human gastrocnemius/soleus muscle at 1.5 Tesla
Author(s) -
Newcomer Bradley R.,
Boska Michael D.
Publication year - 1999
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/(sici)1522-2594(199903)41:3<486::aid-mrm10>3.0.co;2-#
Subject(s) - isometric exercise , chemistry , phosphocreatine , nuclear magnetic resonance , plantar flexion , gastrocnemius muscle , calf muscle , soleus muscle , nuclear medicine , skeletal muscle , medicine , anatomy , physics , energy metabolism , ankle
This study has measured the apparent 31 P T 1 times at 1.5 T in human gastrocnemius/soleus muscle groups at rest, during exercise, and during recovery from a 90‐sec submaximal plantar flexion exercise. T 1 times were measured with a 10‐sec time resolution in 11 normally active volunteers using a surface coil with a nine‐point progressive saturation technique. A two‐point short repetition time technique was also used. Both techniques showed similar trends in the apparent T 1 1 times of all the 31 P metabolites at rest, during exercise, and during recovery. For the nine‐point progressive saturation technique, the apparent T 1 of PCr and β‐ATP decreased approximately 20% to a steady‐state value ( P = 0.027 and P = 0.004, respectively). The two‐point short repetition time technique demonstrated a 10% reduction in the apparent T 1 of PCr and β‐ATP. Both techniques demonstrated an apparent T 1 increase of 58% for inorganic phosphate at the beginning of exercise ( P < 0.0001) and a return to resting value during the 90‐sec submaximal isometric contraction. Neither technique showed any significant differences between resting and exercising T 1 times of the α‐ATP and γ‐ATP resonances ( P = 0.06 and P > 0.40, respectively). Magn Reson Med 41:486–494, 1999. © 1999 Wiley‐Liss, Inc.