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Three-dimensional saturation transfer ³¹P-MRI in muscles of the lower leg at 3.0 T.

Parasoglou P, Xia D, Chang G, Regatte RR - Sci Rep (2014)

Bottom Line: However, due to the low MR sensitivity of the (31)P nucleus, most studies on clinically approved magnetic fields (≤3.0 T) have been performed with coarse resolution and limited tissue coverage.We imaged the lower leg muscles of ten healthy volunteers (total experimental time: 40 min, nominal voxel sizes 0.5 mL), and found statistically significant differences between the kinetics of the CK reaction among muscle groups.Our developed technique may allow in the future the early detection of focal metabolic abnormalities in diseases that affect the function of the skeletal muscle.

View Article: PubMed Central - PubMed

Affiliation: Quantitative Multinuclear Musculoskeletal Imaging Group (QMMIG), Department of Radiology, Center for Biomedical Imaging, New York University Langone Medical Center, New York, NY, USA.

ABSTRACT
The creatine kinase (CK) reaction plays a critical role in skeletal muscle function, and can be studied non-invasively using phosphorus ((31)P) saturation transfer (ST) techniques. However, due to the low MR sensitivity of the (31)P nucleus, most studies on clinically approved magnetic fields (≤3.0 T) have been performed with coarse resolution and limited tissue coverage. However, such methods are not able to detect spatially resolved metabolic heterogeneities, which may be important in diseases of the skeletal muscle. In this study, our aim was to develop and implement a (31)P-MRI method for mapping the kinetics of the CK reaction, and the unidirectional phosphocreatine (PCr) to adenosine triphosphate (ATP) metabolic fluxes in muscles of the lower leg on a clinical 3.0 T MR scanner. We imaged the lower leg muscles of ten healthy volunteers (total experimental time: 40 min, nominal voxel sizes 0.5 mL), and found statistically significant differences between the kinetics of the CK reaction among muscle groups. Our developed technique may allow in the future the early detection of focal metabolic abnormalities in diseases that affect the function of the skeletal muscle.

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Related in: MedlinePlus

Water/fat fractions in the lower leg.The water (left) and fat (right) images of a subject (BMI = 30.4) are shown. The fat fraction (right) shows fat infiltration in the leg muscles.
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f2: Water/fat fractions in the lower leg.The water (left) and fat (right) images of a subject (BMI = 30.4) are shown. The fat fraction (right) shows fat infiltration in the leg muscles.

Mentions: Fat infiltration, especially in high body mass index (BMI) subjects, can reduce the volume fraction of lean muscle in a certain volume of tissue affecting quantification of PCr concentration. In order to account for the fat content in the muscle, the Hierarchical IDEAL method15 was applied across all subjects. The fat volume fractions in the TA were 0.035 ± 0.006 across all subjects, significantly lower than in the GL (0.056 ± 0.019, P = 0.012), the GM (0.051 ± 0.020, P < 0.001) and the S (0.063 ± 0.020, P = 0.002) muscles. Figure 2 shows a case of a higher BMI (30.4) subject. The water/fat separation method shows fat infiltration in the leg muscles. The fat volume fraction in the GM was 0.11, and 0.04 in the TA, which, if not accounted for (especially the GM), can lead to under-estimation of the PCr concentration.


Three-dimensional saturation transfer ³¹P-MRI in muscles of the lower leg at 3.0 T.

Parasoglou P, Xia D, Chang G, Regatte RR - Sci Rep (2014)

Water/fat fractions in the lower leg.The water (left) and fat (right) images of a subject (BMI = 30.4) are shown. The fat fraction (right) shows fat infiltration in the leg muscles.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4048915&req=5

f2: Water/fat fractions in the lower leg.The water (left) and fat (right) images of a subject (BMI = 30.4) are shown. The fat fraction (right) shows fat infiltration in the leg muscles.
Mentions: Fat infiltration, especially in high body mass index (BMI) subjects, can reduce the volume fraction of lean muscle in a certain volume of tissue affecting quantification of PCr concentration. In order to account for the fat content in the muscle, the Hierarchical IDEAL method15 was applied across all subjects. The fat volume fractions in the TA were 0.035 ± 0.006 across all subjects, significantly lower than in the GL (0.056 ± 0.019, P = 0.012), the GM (0.051 ± 0.020, P < 0.001) and the S (0.063 ± 0.020, P = 0.002) muscles. Figure 2 shows a case of a higher BMI (30.4) subject. The water/fat separation method shows fat infiltration in the leg muscles. The fat volume fraction in the GM was 0.11, and 0.04 in the TA, which, if not accounted for (especially the GM), can lead to under-estimation of the PCr concentration.

Bottom Line: However, due to the low MR sensitivity of the (31)P nucleus, most studies on clinically approved magnetic fields (≤3.0 T) have been performed with coarse resolution and limited tissue coverage.We imaged the lower leg muscles of ten healthy volunteers (total experimental time: 40 min, nominal voxel sizes 0.5 mL), and found statistically significant differences between the kinetics of the CK reaction among muscle groups.Our developed technique may allow in the future the early detection of focal metabolic abnormalities in diseases that affect the function of the skeletal muscle.

View Article: PubMed Central - PubMed

Affiliation: Quantitative Multinuclear Musculoskeletal Imaging Group (QMMIG), Department of Radiology, Center for Biomedical Imaging, New York University Langone Medical Center, New York, NY, USA.

ABSTRACT
The creatine kinase (CK) reaction plays a critical role in skeletal muscle function, and can be studied non-invasively using phosphorus ((31)P) saturation transfer (ST) techniques. However, due to the low MR sensitivity of the (31)P nucleus, most studies on clinically approved magnetic fields (≤3.0 T) have been performed with coarse resolution and limited tissue coverage. However, such methods are not able to detect spatially resolved metabolic heterogeneities, which may be important in diseases of the skeletal muscle. In this study, our aim was to develop and implement a (31)P-MRI method for mapping the kinetics of the CK reaction, and the unidirectional phosphocreatine (PCr) to adenosine triphosphate (ATP) metabolic fluxes in muscles of the lower leg on a clinical 3.0 T MR scanner. We imaged the lower leg muscles of ten healthy volunteers (total experimental time: 40 min, nominal voxel sizes 0.5 mL), and found statistically significant differences between the kinetics of the CK reaction among muscle groups. Our developed technique may allow in the future the early detection of focal metabolic abnormalities in diseases that affect the function of the skeletal muscle.

Show MeSH
Related in: MedlinePlus