The role of MRI and MRS in the diagnosis of non hydrocephalic macrocrania in infancy and early childhood

Abstract The aim of this study was to determine the key MRI findings in different disease causing macrocrania in early childhood that will help in early detection and diagnosis. Patients and methods This study was conducted on 20 patients (their age ranged from 3.5 months to 5 years) referred to the radiodiagnosis department in the period between February 2013 and June 2014. All patients were subjected to conventional MRI. MRS was done in 8 cases using PRESS 3D multi-voxel chemical shift imaging. Results The patients subdivided into 7 groups. Glutaric aciduria type 1 (40%) MRI showed wide operculum sign; MRS done in 4 patients showed elevated choline with preserved NAA peak. Benign macrocrania of infancy (15%), and MRI showed enlarged cranio-cortical and inter-hemispheric subarachnoid spaces beyond 5 mm, mildly dilated ventricles. Van der Knaap disease (15%) showed bilateral symmetrical confluent white matter dysmyelination with bilateral fronto-temporal subcortical cystic changes .MRS done in 2 patients showed increase in Cho/NAA ratios. Mucopolysaccharidosis (10%) showed dilated Virchow Robin spaces. MRS done in one patient showed decreased NAA, and increased choline/creatine ratio. Canavan disease (10%) MRI showed bilateral symmetrical extensive white matter dysmyelination. MRS showed markedly elevated NAA. Alexander disease (5%) showed bilateral symmetrical white matter dysmyelination with frontal predilection. MRS revealed increased NAA/Cr, increased myo-inositol/Cr, and lactate doublet. Gangliosidosis (5%) MRI showed bilateral symmetrical T2 and FLAIR hyperintense putamen. CT showed bilateral symmetric thalamic hyperdensities. Conclusion MRI can diagnose different causes of non hydrocephalic macrocrania. MRS is helpful in differentiating benign macrocrania of infancy from dysmyelinating diseases and is specific in Canavan Disease.