Three-dimensional ultrasound for the measurement of choroidal melanomas

Objective: To evaluate the reliability of 3-dimensional ultrasound (3D-US) for the measurement of choroidal melanomas. Design: Retrospective case series. Participants: Forty-two consecutive cases of choroidal melanoma imaged with 3D-US. Methods: Tumor measurements obtained with ophthalmoscopy, transillumination , standard ultrasound techniques, 3D-US, and pathological studies, Tumor di ameters, heights, and volumes were compared. Our 3D-US tumor measurement te chniques were tested for intraobserver and interscan reproducibility. Results: Fifty 3D-US images were studied. The 3D-US tumor measurements were found to be reproducible (height coefficient of variation [CV] less than o r equal to3%; diameter CV less than or equal to9.7%; volume CV less than or equal to 13.2%). There was significant correlation with the usual methods of tumor measurement (diameter r=0.76; height r greater than or equal to0.9 8). Significant differences were found between measurements at pathological examination, as compared with both 2-dimensional and 3D-US height measurem ents (range, 0.73-0.83 mm). This finding was thought to be due to specimen shrinkage. Three-dimensional ultrasound was found to be at least as reprodu cible as clinical examination and standard ultrasound techniques used for m easurement of diameter and height of choroidal melanomas. It was our impres sion that the 3D-US volume measurements accounted for the geometry of the t umor better than volume estimates calculated from basal area and tumor heig ht. Conclusions: Three-dimensional ultrasound measurements of choroidal melanom a were reproducible, correlated well with other tumor measurement technique s, and can be used for measurement of choroidal melanomas.