Cerebral metabolic rate for glucose during the first six months of life: an FDG positron emission tomography study.
OBJECTIVE
To measure the local cerebral metabolic rate for glucose (LCMRGlc) in neonatal brains during maturation using positron emission tomography (PET) and 2-[18F]fluoro-2-deoxy-D-glucose (FDG).


METHODS
Twenty infants were studied using PET during the neonatal period. The postconceptional age ranged from 32.7 to 60.3 weeks. All infants had normal neurodevelopment and were normoglycaemic. The development of the infants was carefully evaluated (follow up 12-36 months) clinically, and by using a method based on Gesell Amatruda's developmental diagnosis. LCMRGlc was quantitated using PET derived from FDG kinetics and calculated in the whole brain and for regional brain structures.


RESULTS
LCMRGlc for various cortical brain regions and the basal ganglia was low at birth (from 4 to 16 mumol/100 g/minute). In infants 2 months of age and younger LCMRGlc was highest in the sensorimotor cortex, thalamus, and brain stem. By 5 months, LCMRGlc had increased in the frontal, parietal, temporal, occipital and cerebellar cortical regions. In general, the whole brain LCMRGlc correlated with postconceptional age (r = 0.90; P < 0.001). The change in the glucose metabolic pattern observed in the neonatal brain reflects the functional maturation of these brain regions.


CONCLUSIONS
These findings show that LCMRGlc in infants increases with maturation. Accordingly, when LCMRGlc is measured during infancy, the postconceptional age has to be taken into account when interpretating the results.
Kinnala
A
A
Department of Pediatrics, University of Turku, Finland.
Suhonen-Polvi
H
H
Aärimaa
T
T
Kero
P
P
Korvenranta
H
H
Ruotsalainen
U
U
Bergman
J
J
Haaparanta
M
M
Solin
O
O
Nuutila
P
P
Wegelius
U
U
D000367:Age Factors; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D001933:Brain Stem / Q000378:metabolism; D002525:Cerebellar Cortex / Q000378:metabolism; D002531:Cerebellum / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism; D002675:Child, Preschool; D003847:Deoxyglucose / Q000031:analogs & derivatives; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D012189:Retrospective Studies; D013788:Thalamus / Q000378:metabolism; D014055:Tomography, Emission-Computed
D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose; D005947:Glucose