Radiologic volumetry on a personal computer with a stereologic method

Rationale and Objectives. There is no universally accepted way to estimate organ and tumor volumes, and manual tracing of the outline of an organ or tumor is tedious, time-consuming,and therefore not widely used. The authors developed a stereologic method for estimating organ and tumor volumes with a personal computer and evaluated its accuracy and efficiency with computed tomographic images. Materials and Methods. CT images were obtained of a 200-cm(3) phantom sphere, a normal liver, a normal spleen, a brain tumor, and a large abdominopelvic tumor. were estimated with a computer program developed on a personal computer. The estimated volumes were compared with those found with the manual tracing method, which was used as a standard of reference. The time to complete each procedure was recorded. Results. When approximately 200 grid points were used, the volumes estimated with the computer were varied from the reference by 1.9%-4.5%. The volumes ranged from 51 to 2,679 cm(3), and the time to estimate these ranged from 42 to 96 seconds. Conclusion. Stereologic estimation of organ and tumor volumes from cross-sectional images with a personal computer can be accurate and efficient at a relatively low cost.