Variability of three-dimensional ultrasonography for assessment of intraocular tumours

• Published in: Canadian journal of ophthalmology 2002-08, Vol.37 (5), p.283-289
• Main Authors: Maberley, David, Fisher, Yale, Carvahlo, Claudio, Goldbaum, Mauro, Raboud, Janet, Shields, Jerry A., Chang, Stanley, Yannuzzi, Lawrence A.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Choroid Neoplasms - diagnostic imaging; Choroid Neoplasms - pathology; Ent, orbit; Hemangioma, Capillary - diagnostic imaging; Hemangioma, Capillary - pathology; Humans; Imaging, Three-Dimensional - methods; Investigative techniques, diagnostic techniques (general aspects); measurement; Medical sciences; Melanoma - diagnostic imaging; Melanoma - pathology; Observer Variation; Reproducibility of Results; Retinal Neoplasms - diagnostic imaging; Retinal Neoplasms - pathology; tumour; Ultrasonic investigative techniques; Ultrasonography; ultrasound; variability
• ISSN: 0008-4182; 1715-3360
• DOI: 10.1016/S0008-4182(02)80023-0

Background: Variability is introduced in three-dimensional (3-D) ultrasound assessments of intraocular tumours when multiple observers examine the same tumour or when multiple scans and measurements of the same tumour are carried out. We evaluated the magnitude and sources of variation associated with 3-D ultrasound measurements of choroidal tumour volume. Methods: Three examiners performed 3-D ultrasonography of five choroidal tumours. Each examiner performed three scans of each tumour and then measured each scan three times to determine the volume. We determined the variation attributable to differences between examiners, scans and measurements by evaluating the contribution of each to the overall variation in tumour volume. A similar process was performed for tumour height for comparison purposes. Results: The reliability of tumour volume measurements was found to be very high. The amount of overall variation, as defined by the coefficient of variation, was similar for tumour volume and tumour height and ranged from 4% to 17%. A total of 97% of the variation in tumour volume measurements and 84% of the variation in tumour height measurements was due to differences between tumours. Differences between examiners accounted for the most of the remaining variation (2% for volume and 7% for height). Interpretation: Three-dimensional ultrasonography of intraocular tumours was highly reliable. Differences between examiners were the main source of variation. Contexte : L'on ne connaît pas le degré de variabilité des évaluations ultrasonores tridimensionnelles (3-D) des tumeurs oculaires, lorsque plusieurs spécialistes examinent la même tumeur ou qu'on en fait plusieurs échographies et mesures. Nous avons apprécié les sources de variation associées à la mesure ultrasonore 3-D du volume de tumeurs choroïdiennes. Méthodes: Trois examinateurs ont fait des échographies 3-D de cinq tumeurs de la choroïde. Chacun a fait trois echographies de chaque tumeur et a mesuré chaque échographie trois fois pour établir le volume des tumeurs. Nous avons établi les variations dues aux écarts entre les examinateurs, les échographies et les mesures, en évaluant la contribution de chacun à l'ensemble des variations portant sur le volume des tumeurs. On a suivi le meme procédé pour ce qui est de la taille des tumeurs, afin de comparer les diverses sources de variation. Résultats : L'on a constaté que la fiabilité des mesures du volume des tumeurs était très élevée. Dans l'ensemble, le