The effects of the method of death and lapsed time on proton relaxation time T1 in autopsied muscle samples.
OBJECTIVE
The variation of measured magnetic resonance T1 relaxation times of autopsied human muscle samples is confusing. Hence, the authors studied rats' muscles to evaluate the effect of fiber type, the relative area of nonmyofiber space, fat and water content, cell death, and the mechanism of death on proton T1.


METHODS
Rats were studied on a 0.1 T magnetic resonance device. We studied how death by cervical dislocation, pentobarbital injection, or a combination of these methods, as well as the amount of time lapsed after death, variably affected T1.


RESULTS
Death itself did not affect T1, but the mechanism of death did: rats killed by cervical dislocation after ether anesthesia had longer T1 than those killed with an overdose of pentobarbital. T1 was significantly shorter 1 day after death than at 4 hours after and returned to baseline levels within 4 days after death. Repeated warming caused variation in T1 and obscured other possible changes.


CONCLUSIONS
Investigation methods should be strictly controlled and standardized before measurements of the relaxation time, T1, of muscle tissue will provide consistent results.
Alanen
A M
AM
Departments of Diagnostic Radiology and Pathology, Turku University Central Hospital, Finland.
Parkkola
R K
RK
Lillsunde
I G
IG
Virtanen
K O
KO
Kalimo
H O
HO
Komu
M E
ME
Kormano
M J
MJ
D000818:Animals; D002423:Cause of Death; D002574:Cervical Vertebrae / Q000293:injuries; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009132:Muscles / Q000473:pathology*; D010424:Pentobarbital / Q000506:poisoning; D011180:Postmortem Changes; D051381:Rats; D017208:Rats, Wistar; D013124:Spinal Injuries / Q000473:pathology; D013997:Time Factors
D010424:Pentobarbital