title: Measuring partial body potassium in the arm versus total body potassium.
abstract: Skeletal muscle (SM), the body's main structural support, has been implicated in metabolic, physiological, and disease processes in humans. Despite being the largest tissue in the human body, its assessment remains difficult and indirect. However, being metabolically active it contains over 50% of the total body potassium (TBK) pool. We present our preliminary results from a new system for measuring partial body K (PBK) that presently are limited to the arm yet provide a direct and specific measure of the SM. This uniquely specific quantification of the SM mass in the arm, which is shielded from the body during measurement, allows us to simplify the assumptions used in deriving the total SM, thereby possibly improving the modeling of the human body compartments. Preliminary results show that PBK measurements are consistent with those from the TBK previously obtained from the same subjects, thus offering a simpler alternative to computed tomography and magnetic resonance imaging used for the same purposes. The PBK system, which can be set up in a physician's office or bedside in a hospital, is completely passive, safe, and inexpensive; it can be used on immobilized patients, children, pregnant women, or other at-risk populations.
authors.affiliation: Brookhaven National Laboratory, Medical Department, Upton, NY 11973, USA. lwielo@bnl.gov
authors.forename: L
authors.initials: L
authors.lastname: Wielopolski
authors.forename: L M
authors.initials: LM
authors.lastname: Ramirez
authors.forename: D
authors.initials: D
authors.lastname: Gallagher
authors.forename: S R
authors.initials: SR
authors.lastname: Sarkar
authors.forename: F
authors.initials: F
authors.lastname: Zhu
authors.forename: G A
authors.initials: GA
authors.lastname: Kaysen
authors.forename: N W
authors.initials: NW
authors.lastname: Levin
authors.forename: S B
authors.initials: SB
authors.lastname: Heymsfield
authors.forename: Z M
authors.initials: ZM
authors.lastname: Wang
mesh_terms: D000328:Adult; D000465:Algorithms; D001132:Arm / Q000502:physiology*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D009928:Organ Specificity; D011188:Potassium / Q000032:analysis*; D011197:Potassium Radioisotopes / Q000032:analysis; D011865:Radioisotope Dilution Technique; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013051:Spectrometry, Gamma / Q000379:methods*; D014018:Tissue Distribution; D014915:Whole-Body Counting / Q000379:methods*
chemical_list: D011197:Potassium Radioisotopes; D011188:Potassium