Inter-observer variability between radiologists reporting on cerebellopontine angle tumours on magnetic resonance imaging.
BACKGROUND
Studies demonstrate the significance of intra- and inter-observer variability when measuring cerebellopontine angle tumours on magnetic resonance imaging, with measured differences as high as 2 mm.


OBJECTIVE
To determine intra- and inter-observer measurement variability of cerebellopontine angle tumours in a specialised institution.


METHODS
The magnetic resonance imaging maximal diameter of 12 randomly selected cerebellopontine angle tumours were independently measured by 4 neuroradiologists at a tertiary referral centre using a standard definition for maximal tumour diameter. Average deviation and intraclass correlation were subsequently calculated.


RESULTS
Inter-observer difference averaged 0.33 ± 0.04 mm (range, 0.0-0.8 mm). Intra-observer measurements were more consistent than inter-observer measurements, with differences averaging 0.17 mm (95 per cent confidence interval = 0.27-0.06, p = 0.002). Inter-observer reliability was 0.99 (95 per cent confidence interval = 0.97-0.99), suggesting high reliability between the readings.


CONCLUSIONS
The use of a standard definition for maximal tumour volume provided high reliability amongst radiologists' readings. To avoid oversizing tumours, it is recommended that conservative monitoring be conducted by the same institution with thin slice magnetic resonance imaging scans.
University of New South Wales,Sydney,Australia.
S R
SR
Teh
Department of Otolaryngology,St Vincent's Private Hospital,Sydney,Australia.
S
S
Ranguis
Department of Otolaryngology,St Vincent's Private Hospital,Sydney,Australia.
P
P
Fagan
D006801:Humans; D008279:Magnetic Resonance Imaging; D009464:Neuroma, Acoustic / Q000000981:diagnostic imaging* / Q000473:pathology; D015588:Observer Variation; D011871:Radiology; D015203:Reproducibility of Results; D047368:Tumor Burden
Acoustics; Cerebellopontine Angle; Magnetic Resonance Imaging; Neuroma; Observer Variation; Reproducibility Of Results