Quantitative Features of Liver Lesions, Lung Nodules, and Renal Stones at Multi Detector Row CT Examinations: Dependency on Radiation Dose and Reconstruction Algorithm.
PURPOSE To determine if radiation dose and reconstruction algorithm affect the computer based extraction and analysis of quantitative imaging features in lung nodules, liver lesions, and renal stones at multi detector row computed tomography (CT) MATERIALS AND METHODS Retrospective analysis of data from a prospective, multicenter, HIPAA compliant, institutional review board approved clinical trial was performed by extracting 23 quantitative imaging features (size, shape, attenuation, edge sharpness, pixel value distribution, and texture) of lesions on multi detector row CT images of 20 adult patients (14 men, six women; mean age, 63 years; range, 38 72 years) referred for known or suspected focal liver lesions, lung nodules, or kidney stones. Data were acquired between September 2011 and April 2012. All multi detector row CT scans were performed at two different radiation dose levels; images were reconstructed with filtered back projection, adaptive statistical iterative reconstruction, and model based iterative reconstruction (MBIR) algorithms. A linear mixed effects model was used to assess the effect of radiation dose and reconstruction algorithm on extracted features. RESULTS Among the 23 imaging features assessed, radiation dose had a significant effect on five, three, and four of the features for liver lesions, lung nodules, and renal stones, respectively (P .002 for all comparisons) Adaptive statistical iterative reconstruction had a significant effect on three, one, and one of the features for liver lesions, lung nodules, and renal stones, respectively (P .002 for all comparisons) MBIR reconstruction had a significant effect on nine, 11, and 15 of the features for liver lesions, lung nodules, and renal stones, respectively (P .002 for all comparisons) Of note, the measured size of lung nodules and renal stones with MBIR was significantly different than those for the other two algorithms (P .002 for all comparisons) Although lesion texture was significantly affected by the reconstruction algorithm used (average of 3.33 features affected by MBIR throughout lesion types; P .002, for all comparisons) no significant effect of the radiation dose setting was observed for all but one of the texture features (P .002 .998) CONCLUSION Radiation dose settings and reconstruction algorithms affect the extraction and analysis of quantitative imaging features in lesions at multi detector row CT.
Radiology