Comparative prognostic utilities of early quantitative magnetic resonance imaging spin-spin relaxometry and proton magnetic resonance spectroscopy in neonatal encephalopathy.
OBJECTIVE
We sought to compare the prognostic utilities of early MRI spin-spin relaxometry and proton magnetic resonance spectroscopy in neonatal encephalopathy.


METHODS
Twenty-one term infants with neonatal encephalopathy were studied at a mean age of 3.1 days (range: 1-5). Basal ganglia, thalamic and frontal, parietal, and occipital white matter spin-spin relaxation times were determined from images with echo times of 25 and 200 milliseconds. Metabolite ratios were determined from an 8-mL thalamic-region magnetic resonance spectroscopy voxel (1H point-resolved spectroscopy; echo time 270 milliseconds). Outcomes were assigned at age 1 year as follows: (1) normal, (2) moderate (neuromotor signs or Griffiths developmental quotient of 75-84), (3) severe (functional neuromotor deficit or developmental quotient <75 or died). Predictive efficacies for differentiation between normal and adverse (combined moderate and severe) outcomes were compared by receiver operating characteristic curve analysis and logistic regression.


RESULTS
Thalamic and basal ganglia spin-spin relaxation times correlated positively with outcome and predicted adversity. Although thalamic and basal ganglia spin-spin relaxation times were prognostic of adversity, magnetic resonance spectroscopy metabolite ratios were better predictors, and, of these, lactate/N-acetylaspartate was most accurate.


CONCLUSIONS
Deep gray matter spin-spin relaxation time was increased in the first few days after birth in infants with an adverse outcome. Proton magnetic resonance spectroscopy was more prognostic than spin-spin relaxation time, with lactate/N-acetylaspartate the best measure. Nevertheless, both techniques were useful for early prognosis, and the potential superior spatial resolution of spin-spin relaxometry may define better the precise anatomic pattern of injury in the early days after birth.
Shanmugalingam
Shanthi
S
Centre for Perinatal Brain Research, Institute for Women's Health, London, United Kingdom.
Thornton
John S
JS
Iwata
Osuke
O
Bainbridge
Alan
A
O'Brien
Frances E
FE
Priest
Andrew N
AN
Ordidge
Roger J
RJ
Cady
Ernest B
EB
Wyatt
John S
JS
Robertson
Nicola J
NJ
D001923:Brain Chemistry; D001927:Brain Diseases / Q000175:diagnosis* / Q000473:pathology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D016015:Logistic Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D011237:Predictive Value of Tests; D011379:Prognosis; D011522:Protons; D012372:ROC Curve; D014867:Water / Q000032:analysis
D011522:Protons; D014867:Water