Matthias Hammon1, Susan Grossmann2, Peter Linz3, Christoph Kopp3, Anke Dahlmann3, Rolf Janka2, Alexander Cavallaro2, Michael Uder2, Jens Titze4. 1. Department of Radiology, University Hospital Erlangen, Maximiliansplatz 1, Erlangen 91054, Germany. Electronic address: matthias.hammon@uk-erlangen.de. 2. Department of Radiology, University Hospital Erlangen, Maximiliansplatz 1, Erlangen 91054, Germany. 3. Department of Nephrology and Hypertension, University Hospital Erlangen, Erlangen, Germany. 4. Department of Medicine, Vanderbilt University, Nashville, Tennessee.
Abstract
RATIONALE AND OBJECTIVES: The aim of the work described here was to determine the feasibility of monitoring Na(+) concentration and distribution in muscle/skin during aerobic/anaerobic exercise with (23)Na magnetic resonance imaging (MRI). MATERIALS AND METHODS: The Na(+) concentration and water content of muscle/skin of the left lower leg of six healthy subjects (mean age, 26 years; range, 22-30 years; three men and three women) were assessed before and after aerobic/anaerobic cycle ergometry and during recovery with 3-T (23)Na/(1)H MRI. (23)Na MRI was performed with a custom-made knee coil. A gradient echo sequence with an acquisition time of 3.25 minutes, echo time of 2.07 ms, repetition time of 100 ms, and spatial resolution of 3 × 3 × 30 mm(3) was applied. Phantoms with increasing sodium concentration served for quantification via linear extrapolation. Blood values were determined by blood gas analysis. RESULTS: The concentration of Na(+) significantly increased during anaerobic exercise in all muscle compartments except the medial gastrocnemius muscle, whereas no significant change was observed in most muscle compartments during aerobic exercise (only the soleus muscle exhibited a significant increase in Na(+) concentration during aerobic exercise: 1.6 ± 1.5 mmol/kg, 4.5%, P = .046). During anaerobic exercise, the mean Na(+) concentration of the triceps surae and the whole leg increased by 9.0% (3.1 ± 2.1 mmol/kg, P = .016) and 6.5% (2.2 ± 1.3 mmol/kg, P < .01). MRI revealed a water-independent increase in Na(+) concentration in most muscle compartments during anaerobic exercise. Na(+) concentration significantly decreased during recovery after anaerobic and aerobic exercise in all muscle compartments except the soleus. The Na(+) concentration of the skin did not significantly change during anaerobic/aerobic exercise. CONCLUSIONS: Sodium(23) MRI allows reliable and noninvasive visualization and quantification of Na(+) concentration and distribution in muscle and skin during exercise. (23)Na MRI can be used to gain new insights into Na(+) homeostasis, presumably leading to better comprehension of pathophysiology.
RATIONALE AND OBJECTIVES: The aim of the work described here was to determine the feasibility of monitoring Na(+) concentration and distribution in muscle/skin during aerobic/anaerobic exercise with (23)Na magnetic resonance imaging (MRI). MATERIALS AND METHODS: The Na(+) concentration and water content of muscle/skin of the left lower leg of six healthy subjects (mean age, 26 years; range, 22-30 years; three men and three women) were assessed before and after aerobic/anaerobic cycle ergometry and during recovery with 3-T (23)Na/(1)H MRI. (23)Na MRI was performed with a custom-made knee coil. A gradient echo sequence with an acquisition time of 3.25 minutes, echo time of 2.07 ms, repetition time of 100 ms, and spatial resolution of 3 × 3 × 30 mm(3) was applied. Phantoms with increasing sodium concentration served for quantification via linear extrapolation. Blood values were determined by blood gas analysis. RESULTS: The concentration of Na(+) significantly increased during anaerobic exercise in all muscle compartments except the medial gastrocnemius muscle, whereas no significant change was observed in most muscle compartments during aerobic exercise (only the soleus muscle exhibited a significant increase in Na(+) concentration during aerobic exercise: 1.6 ± 1.5 mmol/kg, 4.5%, P = .046). During anaerobic exercise, the mean Na(+) concentration of the triceps surae and the whole leg increased by 9.0% (3.1 ± 2.1 mmol/kg, P = .016) and 6.5% (2.2 ± 1.3 mmol/kg, P < .01). MRI revealed a water-independent increase in Na(+) concentration in most muscle compartments during anaerobic exercise. Na(+) concentration significantly decreased during recovery after anaerobic and aerobic exercise in all muscle compartments except the soleus. The Na(+) concentration of the skin did not significantly change during anaerobic/aerobic exercise. CONCLUSIONS:Sodium(23) MRI allows reliable and noninvasive visualization and quantification of Na(+) concentration and distribution in muscle and skin during exercise. (23)Na MRI can be used to gain new insights into Na(+) homeostasis, presumably leading to better comprehension of pathophysiology.
Authors: Jens Titze; Natalia Rakova; Christoph Kopp; Anke Dahlmann; Jonathan Jantsch; Friedrich C Luft Journal: Nephrol Dial Transplant Date: 2015-09-25 Impact factor: 5.992
Authors: Rachelle Crescenzi; Adriana Marton; Paula M C Donahue; Helen B Mahany; Sarah K Lants; Ping Wang; Joshua A Beckman; Manus J Donahue; Jens Titze Journal: Obesity (Silver Spring) Date: 2017-12-27 Impact factor: 5.002
Authors: Anke Dahlmann; Matthias Hammon; Christoph Kopp; Peter Linz; Alexander Cavallaro; Hannes Seuss; Kai-Uwe Eckardt; Friedrich C Luft; Jens Titze; Michael Uder Journal: Springerplus Date: 2016-05-23