Send to

Choose Destination
Magn Reson Med. 2016 Jun;75(6):2324-31. doi: 10.1002/mrm.25822. Epub 2015 Jun 26.

Dynamic PCr and pH imaging of human calf muscles during exercise and recovery using (31) P gradient-Echo MRI at 7 Tesla.

Author information

MR Centre of Excellence, Medical University of Vienna, Vienna, Austria.
Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.
Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria.
Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria.
Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia.



Simultaneous acquisition of spatially resolved (31) P-MRI data for evaluation of muscle specific energy metabolism, i.e., PCr and pH kinetics.


A three-dimensional (3D) gradient-echo sequence for multiple frequency-selective excitations of the PCr and Pi signals in an interleaved sampling scheme was developed and tested at 7 Tesla (T). The pH values were derived from the chemical shift-induced phase difference between the resonances. The achieved spatial resolution was ∼2 mL with image acquisition time below 6 s. Ten healthy volunteers were studied performing plantar flexions during the delay between (31) P-MRI acquisitions, yielding a temporal resolution of 9-10 s.


Signal from anatomically matched regions of interest had sufficient signal-to-noise ratio to allow single-acquisition PCr and pH quantification. The Pi signal was clearly detected in voxels of actively exercising muscles. The PCr depletions were in gastrocnemius 42 ± 14% (medialis), 48 ± 17% (lateralis) and in soleus 20 ± 11%. The end exercise pH values were 6.74 ± 0.18 and 6.65 ± 0.27 for gastrocnemius medialis and lateralis, respectively, and 6.96 ± 0.12 for soleus muscle.


Simultaneous acquisition of PCr and Pi images with high temporal resolution, suitable for measuring PCr and pH kinetics in exercise-recovery experiments, was demonstrated at 7T. This study presents a fast alternative to MRS for quantifying energy metabolism of posterior muscle groups of the lower leg. Magn Reson Med 75:2324-2331, 2016. © 2015 Wiley Periodicals, Inc.


X-nuclei imaging; dynamic imaging; high energy phosphate; pH; skeletal muscle

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center