In vivo absolute quantification of carnosine in the vastus lateralis muscle with
1H MRS using a surface coil and water as internal reference.
Skeletal Radiol 2023;
52:157-165. [PMID:
35978163 DOI:
10.1007/s00256-022-04149-8]
[Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 08/03/2022] [Accepted: 08/04/2022] [Indexed: 02/02/2023]
Abstract
OBJECTIVE
To standardize a method for 1H MRS intramuscular absolute quantification of carnosine in the thigh, using a surface coil and water as internal reference.
MATERIALS AND METHODS
Carnosine spectra were acquired in phantoms (5, 10, and 15 mM) as well as in the right gastrocnemius medialis (GM) and right vastus lateralis (VLM) muscles of young team sports athletes, using volume (VC) and surface (SC) coils on a 3 T scanner, with the same receiver gain. Water spectra were used as internal reference for the absolute quantification of carnosine.
RESULTS
Phantom's experiments showed a maximum error of 7%, highlighting the validity of the measurements in the study setup. The carnosine concentrations (mmol/kg ww, mean ± SD) measured in the GM were 6.8 ± 2.2 with the VC (CcarVC) and 10.2 ± 3.0 with the SC (CcarSC) (P = 0.013; n = 9). Therefore, a correction was applied to these measurements (CcarVC = 0.6582*CcarSC), to make coils performance comparable (6.8 ± 2.2 for VC and 6.7 ± 2.0 for SC, P = 0.97). After that, only the SC was used to quantify carnosine in the VLM, where a concentration of 5.4 ± 1.5 (n = 30) was found, with significant differences between men (6.2 ± 1.3; n = 15) and women (4.6 ± 1.2; n = 15). The error in quantitation was 5.3-5.5% with both coils.
CONCLUSION
The method using the SC and water as internal reference can be used to quantify carnosine in voluminous muscles and regions of the body in humans, where the VC is not suitable, such as the VLM.
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