The use of short-echo-time 1H MRS for childhood cerebellar tumours prior to histopathological diagnosis.
BACKGROUND
Proton magnetic resonance spectroscopy (MRS) measures concentrations of metabolites in vivo and provides a powerful method for identifying tumours. MRS has not entered routine clinical use partly due to the difficulty of analysing the spectra.


OBJECTIVE
To create a straightforward method for interpreting short-echo-time MRS of childhood cerebellar tumours.


METHODS
Single-voxel MRS (1.5-T Siemens Symphony NUM4, TR/TE 1,500/30 ms) was performed at presentation in 30 children with cerebellar tumours. The MRS results were analysed for comparison with histological diagnosis. Peak heights for N-acetyl aspartate (NAA), creatine (Cr), choline (Cho) and myo-inositol (mIns) were determined and receiver operator characteristic curves used to select ratios that best discriminated between the tumour types. The method was implemented by a group of clinicians and scientists, blinded to the results.


RESULTS
A total of 27 MRS studies met the quality control criteria. NAA/Cr >4.0 distinguished all but one of the astrocytomas from the other tumours. A combination of Cr/Cho <0.75 and mIns/NAA <2.1 separated all the medulloblastomas from the ependymomas.


CONCLUSIONS
Peak height ratios from short-echo-time MRS can accurately predict the histopathology of childhood cerebellar tumours.
Harris
Lisa M
LM
Academic Department of Paediatrics and Child Health, University of Birmingham, Whittall Street, Birmingham, B4 6NH, UK.
Davies
Nigel
N
Macpherson
Lesley
L
Foster
Katharine
K
Lateef
Shaheen
S
Natarajan
Kal
K
Sgouros
Spyridon
S
Brundler
Marie-Anne
MA
Arvanitis
Theodoros N
TN
Grundy
Richard G
RG
Peet
Andrew C
AC
D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis*; D002528:Cerebellar Neoplasms / Q000175:diagnosis* / Q000378:metabolism*; D002531:Cerebellum / Q000378:metabolism; D002648:Child; D002794:Choline / Q000032:analysis*; D003401:Creatine / Q000032:analysis*; D006801:Humans; D007294:Inositol / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D011522:Protons; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016037:Single-Blind Method