PC.30 3T proton magnetic resonance spectroscopy in neonatal encephalopathy: lactate/n-acetylaspartate prognosis. (9th June 2014)

• Record Type: Journal Article
• Authors: Badii, S; Uria-Avellanal, C; Bainbridge, A; Price, D; Dinan, M; Kendall, J; Robertson, NJ
• Is Part Of: Archives of disease in childhood. Volume 99:Supplement 1(2014)
• Page Start: A46
• Page End: A46
• Publication Date: 2014-06-09
• Subjects: Infants -- Diseases -- Periodicals; Newborn infants -- Diseases -- Periodicals; Fetus -- Diseases -- Periodicals; 618.920105
• DOI: 10.1136/archdischild-2014-306576.131
• Languages: English
• ISSNs: 1359-2998

Abstract

Abstract : Introduction: Lactate (Lac) / N-acetyl-aspartate (Naa) peak area ratio measured at long echo time on proton magnetic resonance spectroscopy (1H MRS) in the thalamus is a robust biomarker of outcome between day 5–14 in babies presenting with neonatal encephalopathy (NE). 1 Previous studies have been done at 2.35 and 1.5 Tesla; a specific median Lac/Naa threshold of 0.29 differentiated those infants with subsequent good and adverse outcome at 2 years. The optimum threshold may differ at higher field strengths (eg 3 Tesla) as the T2 values of Lac and Naa will be different to those at lower field. Aim: To determine whether the threshold for assigning prognosis is altered at 3 Tesla. Patients and methods: 42 infants with NE were scanned using 1H MRS (PRESS: TR = 2298 ms, TE = 288 ms, 1.5cm 3 voxel in thalamus) at 3 Tesla. Of these, 26 (gestational age: 39.6 +/- 0.3 weeks, birth weight: 3155 ± 425 grams, postnatal age at scan 5.6 +/- 1.7 days; mean +/- SD) had 12 month clinical follow up using Bayley III scales. 20 infants had good outcomes (normal or mild impairment) and 6 had adverse outcomes (death or severe disability). Results: Figure 1 shows the ROC curve for Lac/Naa. Using a 0.29 threshold yielded a true positive rate of 100% for adverse outcomes with 2 false positive results. (PPV: 0.75; NPV: 1.00) Conclusion: A thalamic 1H MRS Lac/Naa peak area ratio threshold of 0.29 differentiates babies with subsequent normal and adverse outcomes at 3T. Reference: Thayyil S, Chandrasekaran M, Taylor AM, Bainbridge A, Cady EB, Chong WK, Murad S, Omar RZ, Robertson NJ. In-vivo cerebral magnetic resonance biomarkers for predicting long-term neurodevelopmental outcome following neonatal encephalopathy: A meta-analysis. Pediatrics . 2010;125(2):e382–e395