Radiology, Vol 171, 449-453, Copyright © 1989 by Radiological Society of North America
Nonacute subdural hematoma: fundamental interpretation of MR images based on biochemical and in vitro MR analysis
T Ebisu, S Naruse, Y Horikawa, C Tanaka and T Higuchi
Department of Neurosurgery, Kyoto Prefectural University of Medicine, Japan.
Few reports have described the nature of the appearance of nonacute
subdural hematoma on magnetic resonance (MR) images. The authors analyzed
MR images in 39 cases of nonacute subdural hematoma and subdural effusion
by measuring in vitro proton relaxation times and the biochemical variables
of hematoma fluids. T1 became proportionally shorter than T2 with an
increase in hematocrit but the direct cause of the variation in T1 and T2
was the amount of methemoglobin. The free iron content, not the bound iron
content, was another main cause for shortened T1 and T2. Paradoxical
findings in the correlation between the total protein or albumin
concentration and relaxation times were noted. It is possible that as the
protein level in the supernatant increased, more free iron was bound to the
protein, decreasing the influence of the free iron on the relaxation times.
