The validity of routine brain MRI in detecting post-laminar optic nerve involvement in retinoblastoma.
OBJECTIVE
To describe the diagnostic validity of a gadolinium-enhanced routine brain MRI scan with 5 mm section thickness for the detection of optic nerve involvement in patients with retinoblastoma.


METHODS
Medical records of primarily enucleated retinoblastoma patients who underwent routine preoperative brain MRI scan with section thickness of 5 mm were retrospectively reviewed. Preoperative magnetic resonance images were independently reviewed in a masked fashion by two radiologists and compared with histological findings.


RESULTS
41 eyes of 41 patients were included and the mean age at enucleation was 23.1 months. Among 41 eyes, 14 eyes were diagnosed to have post-laminar optic nerve invasion on histopathology. The accuracy, sensitivity and specificity of MRI for the diagnosis of post-laminar invasion were 73.2%, 35.7% and 92.6%, respectively, by the first radiologist and 78.0%, 42.9% and 96.3%, respectively, by the second radiologist. Moderate agreement was found between two radiologists (κ =0.48, p<0.01).


CONCLUSIONS
Compared with the results of previous studies using orbital MRI with less than 3 mm section thickness, routine brain MRI with section thickness of 5 mm showed comparable specificity but inferior sensitivity in detecting optic nerve involvement of retinoblastoma.
Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea.
Byung Joo
BJ
Lee
Jeong Hun
JH
Kim
Dong Hun
DH
Kim
Sung-Hye
SH
Park
Young Suk
YS
Yu
D005260:Female; D005682:Gadolinium; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards* / Q000706:statistics & numerical data; D008297:Male; D015588:Observer Variation; D009900:Optic Nerve / Q000473:pathology; D019574:Optic Nerve Neoplasms / Q000473:pathology*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D019572:Retinal Neoplasms / Q000473:pathology*; D012175:Retinoblastoma / Q000473:pathology*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
D005682:Gadolinium