Course of murine leukemia retrovirus infection determined in vivo by magnetic resonance imaging.
Magnetic resonance imaging was applied to measure the volumes of spleens and lymph nodes of mice infected with three different leukemia retroviruses (LP-BM5 murine leukemia virus, Friend, and Rauscher) in vivo. Anesthesia by rapid intraperitoneal injection of Saffan was sufficient for magnetic resonance imaging and could be repeated at appropriate intervals. Eleven frontal magnetic resonance images through the abdomen with a center-to-center distance of 1.5 mm between adjacent slices were acquired simultaneously. To optimally demarcate spleens from the surrounding tissues, the magnetic resonance images were mildly T2-weighted for mice infected with LP-BM5 murine leukemia virus and mildly T1-weighted for those infected with Friend and Rauscher virus. Measurements requiring only 3 to 4 hours in groups of 24 to 28 mice were accomplished by using a standardized holder (i) accommodating two animals in the supine position and (ii) ensuring reproducible positioning in the magnetic resonance-instrument, and (iii) by reducing the number of phase-encoding steps of mildly T2-weighted magnetic resonance images from 256 to 128. Volumes of spleens and inguinal lymph nodes were calculated from the respective cross-sectional areas. The weights and magnetic resonance image-derived volumes of spleens and inguinal lymph nodes correlated well (r greater than 0.95). Despite large variations in the extent of splenomegaly and lymphadenopathy at any given time, the progression of the disease could easily be followed by repeating magnetic resonance imaging at intervals. Thus, statistically relevant results can be obtained in an infection model requiring the use of only a few animals.
Allegrini
P R
PR
Physics Department, CIBA GEIGY Limited, Basle, Switzerland.
Wachsmuth
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ED
D000530:Alfaxalone Alfadolone Mixture / Q000494:pharmacology; D000758:Anesthesia; D000818:Animals; D005260:Female; D005622:Friend murine leukemia virus; D006400:Hematocrit; D009052:Leukemia Virus, Murine; D007942:Leukemia, Experimental / Q000175:diagnosis*; D008198:Lymph Nodes / Q000473:pathology; D008279:Magnetic Resonance Imaging; D051379:Mice; D008810:Mice, Inbred C57BL; D011925:Rauscher Virus; D013154:Spleen / Q000473:pathology
D000530:Alfaxalone Alfadolone Mixture