J Genet Med.  2012 Dec;9(2):84-88. 10.5734/JGM.2012.9.2.84.

Correlation Between Unidentified Bright Objects on Brain Magnetic Resonance Imaging (MRI) and Cerebral Glucose Metabolism in Patients with Neurofibromatosis Type 1

• Sohn YB
• An YS
• Lee SJ
• Choi JW
• Jeong SY
• Kim HJ
• Ko JM

• KMID: 1428899
• DOI: http://doi.org/10.5734/JGM.2012.9.2.84

Abstract

PURPOSE
Neurofibromatosis type 1 (NF1), which is caused by mutations of the NF1 gene, is the most frequent single gene disorder to affect the nervous system. Unidentified bright objects (UBOs) are commonly observed on brain magnetic resonance imaging (MRI) in patients with NF1. However, their clinical and pathologic significance is not well understood. The purpose of this study was to investigate the correlation between UBOs and cerebral glucose metabolism measured by 18F-2-Fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET) in Korean patients with NF1.
MATERIALS AND METHODS
Medical records of 75 patients (34 males and 41 females) with NF1 who underwent brain MRI and PET between 2005 and 2011 were evaluated retrospectively. Clinical data including demographics, neurological symptoms, and brain MRI and PET findings, were reviewed.
RESULTS
UBOs were detected in the brain MRI scans of 31 patients (41%). The region most frequently affected by UBOs was the basal ganglia. The most frequent brain PET finding was thalamic glucose hypometabolism (45/75, 60%). Of the 31 patients with UBOs, 26 had thalamic glucose hypometabolism on brain PET, but the other 5 had normal brain PET findings. Conversely, of the 45 patients with thalamic glucose hypometabolism on brain PET, 26 showed UBOs on their brain MRI scans, but 19 had normal findings on brain MRI scans.
CONCLUSION
UBOs on brain MRI scans and thalamic glucose hypometabolism on PET appear to be 2 distinctive features of NF1 rather than correlated symptoms. Because the clinical significance of these abnormal imaging findings remains unclear, a longitudinal follow-up study of changes in clinical manifestations and imaging findings is necessary.

Keyword

Neurofibromatosis 1; Unidentified bright objects; Positron emission tomography; Cerebral glucose metabolism

MeSH Terms

Basal Ganglia
Brain
Demography
Follow-Up Studies
Genes, Neurofibromatosis 1
Glucose
Humans
Magnetic Resonance Imaging
Magnetic Resonance Spectroscopy
Magnetics
Magnets
Male
Medical Records
Nervous System
Neurofibromatoses
Neurofibromatosis 1
Positron-Emission Tomography
Retrospective Studies
Glucose