Epiphyseal marrow in infancy: MR imaging.
Hypointense epiphyseal marrow on T1-weighted magnetic resonance images often suggests disease. To determine whether hypointense marrow sometimes represents normal red marrow in a recently ossified epiphyseal center, the authors studied 38 infants without known marrow disease. Patients with hypointense epiphyseal marrow on T1-weighted images were younger (3.9 months +/- 3.2) than those with hyperintense marrow (9.6 months +/- 3.9) (P less than .001). T1-weighted imaging and histologic correlation were also performed in animals. The signal was hypointense and the marrow was red in the epiphyseal centers of all newborn animals, while all 6-week-old animals had hyperintense signal and yellow marrow. The authors conclude that hypointense marrow on T1-weighted images represents normal red marrow in a recently formed ossification center in newborn rabbits and lambs, and the same is probably true in humans. Epiphyseal marrow becomes hyperintense within a few months of development of the secondary center of ossification.
Jaramillo
D
D
Department of Radiology, Children's Hospital, Boston, MA 02115.
Laor
T
T
Hoffer
F A
FA
Zaleske
D J
DJ
Cleveland
R H
RH
Buchbinder
B R
BR
Egglin
T K
TK
D000818:Animals; D000831:Animals, Newborn / Q000033:anatomy & histology; D001853:Bone Marrow / Q000033:anatomy & histology*; D004838:Epiphyses / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D010012:Osteogenesis; D011817:Rabbits; D012016:Reference Values; D012756:Sheep