Volumetry of Artificial Pulmonary Nodules inEx VivoPorcine Lungs: Comparison of Semi-automated Volumetry and Radiologists' Performance

Abstract

Purpose: With the advent of MSCT, the detection rate of small pulmonary nodules is markedly greater. However, there is no definite diagnostic clue to differentiate between malignant and benign nodules, except for the interval growth in small nodule less than 1 cm in diameter. We evaluated the accuracy of computeraided volumetry (CAV) and compared it with 4 radiologists' measurement. Materials and Methods: Fifteen artificial nodules that were embedded in the ex vivo porcine lung were scanned by MSCT. The diameters and volumes of nodules were independently measured three times, at 5-day intervals, and by four radiologists as well as by CAV. We evaluated the accuracy of the measurements on the basis of the true diameter and volume of the nodules. Using a paired t-test and a Bland-Altman plot, we evaluated whether there was a statistically significant difference between the radiologists' measurements and the CAV. Results: The accuracy of the manual measurements by radiologists revealed a statistically significant difference from the true diameter and volume of the artificial nodules (p0.01) Conclusion: The results of this study suggest that CAV is an accurate and useful tool to evaluate the volume of pulmonary nodules and can eventually be used to differentiate malignant and benign nodules as well as evaluate the therapeutic response of lung cancer.