Quantitation of ellipsoid tumor areas using a circumferential measuring device.
A controlled trial of a new circumferential area measuring device, the Tumorimeter, was performed on a set of 30 radiographs of chest nodules ranging in size from 1.5 to 5.0 cm diameter. The Tumorimeter is a hand-held device with a sliding radiolucent loop used to circumferentially measure ellipsoid tumors. It is calibrated in cm2 of surface area. In a crossover comparison with standard Vernier-type calipers, the Tumorimeter was significantly more accurate than bidimensional caliper determinations (less than or equal to 5% surface area error vs a 21-28% overestimate error for calipers). It was also more rapid (an average of 10.5 sec for the Tumorimeter vs 22.3 sec for calipers for each measurement). Both results were statistically significant, P less than 0.0001 by analysis of variance. This trial demonstrates that enhanced speed and accuracy in tumor measurement are possible by using ellipsoid assessments of radiographs. A prospective clinical trial is planned to compare rectangular areas obtained using bidimensional tumor widths, with ellipsoid areas obtained by circumferential tumor measurements using the Tumorimeter.
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Department of Medicine, College of Medicine, University of Arizona, Tucson 85724.
Alberts
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D004864:Equipment and Supplies; D006801:Humans; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D011859:Radiography; D011897:Random Allocation; D015203:Reproducibility of Results; D013899:Thoracic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D014894:Weights and Measures