title: Postmortem 31P magnetic resonance spectroscopy of the skeletal muscle: α-ATP/Pi ratio as a forensic tool?
abstract: OBJECTIVE
  Phosphor magnetic resonance spectroscopy ((31)P MRS) is an established method for metabolic examinations of resting and exercising skeletal muscle. So far, there are few MRS investigations of human corpses. The aim of this study was to investigate the temporal postmortem pattern of phosphor metabolites in the adductor magnus muscle and to check the value of MRS as a forensic tool, especially for the determination of the time of death.
  
  
  METHODS
  Eight corpses, died of natural cause, were examined (5 males, 3 females; age: 73±7 y, weight 65.8±15.9 kg). A control group of 3 subjects (2 males, 1 female, mean age: 51±24 y, range: 24-69 y, mean body weight: 84.0±16.5 kg) was examined at a single time point as well. (31)P MRS was performed on a 1.5 T MRI (TR 700 ms, TE 0.35 ms, averages 256, flip angle 90°). A standard (31)P/(1)H heart/liver coil was employed (receiver coil diameter 12 cm). The (31)P MRS scans were repeated in intervals of 1 h over a period from 4.5 to 24 h postmortem (p.m.). The core temperature was rectally measured throughout the MRI examination.
  
  
  RESULTS
  The mean core temperature decreased from 36.0°C to 25.7°C. In vivo and ex vivo spectra showed characteristic differences, especially the PCr metabolite was no longer detectable after 10 h p.m. The α-ATP/Pi ratio decreased with time from 0.445 to 0.032 over 24 h p.m.
  
  
  CONCLUSIONS
  There is a characteristic postmortem time pattern of the phosphor metabolites. Especially the acquired α-ATP/Pi ratio could be described by a significant exponential time course (r(2)=0.92, p<0.001). (31)P MRS might be added to the postmortem imaging methods.
authors: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. Electronic address: tonymanfred.schmidt@gmail.com.
authors: Tony M
authors: TM
authors: Schmidt
authors: Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors: Zhiyue J
authors: ZJ
authors: Wang
authors: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors: Sarah
authors: S
authors: Keller
authors: Department of Legal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors: Axel
authors: A
authors: Heinemann
authors: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors: Suzan
authors: S
authors: Acar
authors: Siemens AG, Hamburg, Germany.
authors: Joachim
authors: J
authors: Graessner
authors: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors: Bjoern P
authors: BP
authors: Schoennagel
authors: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors: Gerhard
authors: G
authors: Adam
authors: Children's Hospital & Research Center Oakland, Oakland, CA, USA; Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors: Roland
authors: R
authors: Fischer
authors: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors: Jin
authors: J
authors: Yamamura
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D049429:Forensic Pathology; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism*; D011180:Postmortem Changes
chemical_list: D010710:Phosphates; D010758:Phosphorus; D000255:Adenosine Triphosphate
keywords: 31P MRS; Forensic; Magnetic resonance imaging; Postmortem; Spectroscopy; Time of death