title: Longstanding tectal tumors: proton MR spectroscopy and diffusion MRI findings.
abstract: Four patients with longstanding tectal tumors are included in this study. The tectal lesion in a neurofibromatosis type 1 (NF1) patient was due to a hamartoma, while others represented gliomas. On spectroscopy, decreased NAA peaks with resultant decreases in the NAA/Cho, and NAA/Cr ratios were observed in two patients. In three patients, on diffusion MRI the tectal tumors were hyperintense on b=1000 s/mm(2) (heavily diffusion-weighted) images. On apparent diffusion coefficient (ADC) maps, they had high signal, and high ADC values (mean=1.20 x 10(-3)mm(2)/s), compared to normal cerebral parenchyma. Diffusion MRI findings suggested that tectal tumors had a relatively high nuclear to cytoplasmic ratio (high-signal on b=1000 s/mm(2) images) in association with a relatively loose intercellular matrix (high ADC values).
authors.affiliation: Department of Radiology, Ege University Hospital, Bornova, Izmir 35100, Turkey. rnsener@hotmail.com
authors.forename: R N
authors.initials: RN
authors.lastname: Sener
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000473:pathology*; D002648:Child; D004058:Diffusion; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D011522:Protons; D003336:Tectum Mesencephali / Q000473:pathology*
chemical_list: D011522:Protons