Magnetic resonance imaging for evaluation of childhood aplastic anemia.
OBJECTIVE
We prospectively evaluated the ability of magnetic resonance imaging (MRI) of the thoraco-lumbar vertebrae to determine the relative amount of red and fatty marrow in children with aplastic anemia.


METHODS
Twenty pediatric patients (ages 1-19 years) with aplastic anemia underwent T1-weighted (T1W, n = 31) and short T1 inversion recovery (STIR, n = 30) MRI of the midline sagittal thoraco-lumbar spine. Bone marrow (BM) biopsies from the posterior iliac crest (n = 29) were also performed. All studies were evaluated by blinded observers; MR grading was based on visual inspection of signal intensity. Biopsy-estimated cellularity was compared with T1W and STIR grading when these were performed within 14 days of each other (n = 16). All studies were compared to a simultaneous absolute neutrophil count (ANC), absolute reticulocyte count (ARC), and platelet count.


RESULTS
BM cellularity estimated by BM biopsy was significantly associated with STIR grading (p = 0.032, Jonckheere-Terpstra test), as were peripheral ANC (p = 0.044), ARC (p = 0.007), and platelet count (p = 0.003). T1W grade was significantly associated with ANC (P = 0.011) but not ARC (p = 0.053) or platelet count (p = 0.377). Biopsy-estimated cellularity was associated with ANC (p = 0.032) and ARC (p = 0.036), but not platelet count (p = 0.282).


CONCLUSIONS
In childhood aplastic anemia patients, STIR (and, to a lesser extent, T1W) MRI of the thoraco-lumbar spine reflects BM activity, as measured by peripheral blood ANC, ARC, and platelet count, and BM cellularity, as measured by BM biopsy. MRI may thus provide a noninvasive measure of hematopoietic status.
Kanwar
V S
VS
Department of Hematology-Oncology, St. Jude Children's Research Hospital, Memphis, TN 38101-0318, USA.
Wang
W C
WC
Winer-Muram
H T
HT
Kauffman
W M
WM
Gronemeyer
S A
SA
Head
D R
DR
D000293:Adolescent; D000328:Adult; D000741:Anemia, Aplastic / Q000175:diagnosis*; D001706:Biopsy; D001772:Blood Cell Count; D001853:Bone Marrow / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male