Yuqin Ding1,2, Daniele Marin1, Federica Vernuccio3, Fernando Gonzalez4, Hannah V Williamson5, Hans-Christoph Becker6, Bhavik N Patel6, Justin Solomon7, Juan Carlos Ramirez-Giraldo8, Ehsan Samei7, Rendon C Nelson1, Mathias Meyer9. 1. Department of Radiology, Duke University Medical Center, 2301 Erwin Rd, Durham, NC, 27710, USA. 2. Department of Radiology, Zhongshan Hospital, Fudan University; Shanghai Institute of Medical Imaging, Shanghai, 200032, China. 3. Department ProMISE (Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties), University Hospital of Palermo, Piazza Delle Cliniche, 90127, Palermo, Italy. 4. Department of Radiology, Clínica Alemana de Santiago, Universidad del Desarrollo, 8320000, Santiago, Chile. 5. Duke Cancer Institute-Biostatistics, Duke University Medical Center, Durham, NC, 27705, USA. 6. Department of Radiology, Stanford University, School of Medicine, Stanford, CA, 94305, USA. 7. The Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, NC, 27705, USA. 8. Siemens Healthineers, 40 Liberty Boulevard, Malvern, PA, 19355, USA. 9. Department of Radiology, Duke University Medical Center, 2301 Erwin Rd, Durham, NC, 27710, USA. mathias.meyer@duke.edu.
Abstract
PURPOSE: To evaluate the variability of quantitative measurements of metastatic liver lesions by using a multi-radiation-dose-level and multi-reader comparison. METHODS: Twenty-three study subjects (mean age, 60 years) with 39 liver lesions who underwent a single-energy dual-source contrast-enhanced staging CT between June 2015 and December 2015 were included. CT data were reconstructed with seven different radiation dose levels (ranging from 25 to 100%) on the basis of a single CT acquisition. Four radiologists independently performed manual tumor measurements and two radiologists performed semi-automated tumor measurements. Interobserver, intraobserver, and interdose sources of variability for longest diameter and volumetric measurements were estimated and compared using Wilcoxon rank-sum tests and intraclass correlation coefficients. RESULTS: Inter- and intraobserver variabilities for manual measurements of the longest diameter were higher compared to semi-automated measurements (p < 0.001 for overall). Inter- and intraobserver variabilities of volume measurements were higher compared to the longest diameter measurement (p < 0.001 for overall). Quantitative measurements were statistically different at < 50% radiation dose levels for semi-automated measurements of the longest diameter, and at 25% radiation dose level for volumetric measurements. The variability related to radiation dose was not significantly different from the inter- and intraobserver variability for the measurements of the longest diameter. CONCLUSION: The variability related to radiation dose is comparable to the inter- and intraobserver variability for measurements of the longest diameter. Caution should be warranted in reducing radiation dose level below 50% of a conventional CT protocol due to the potentially detrimental impact on the assessment of lesion response in the liver.
PURPOSE: To evaluate the variability of quantitative measurements of metastatic liver lesions by using a multi-radiation-dose-level and multi-reader comparison. METHODS: Twenty-three study subjects (mean age, 60 years) with 39 liver lesions who underwent a single-energy dual-source contrast-enhanced staging CT between June 2015 and December 2015 were included. CT data were reconstructed with seven different radiation dose levels (ranging from 25 to 100%) on the basis of a single CT acquisition. Four radiologists independently performed manual tumor measurements and two radiologists performed semi-automated tumor measurements. Interobserver, intraobserver, and interdose sources of variability for longest diameter and volumetric measurements were estimated and compared using Wilcoxon rank-sum tests and intraclass correlation coefficients. RESULTS: Inter- and intraobserver variabilities for manual measurements of the longest diameter were higher compared to semi-automated measurements (p < 0.001 for overall). Inter- and intraobserver variabilities of volume measurements were higher compared to the longest diameter measurement (p < 0.001 for overall). Quantitative measurements were statistically different at < 50% radiation dose levels for semi-automated measurements of the longest diameter, and at 25% radiation dose level for volumetric measurements. The variability related to radiation dose was not significantly different from the inter- and intraobserver variability for the measurements of the longest diameter. CONCLUSION: The variability related to radiation dose is comparable to the inter- and intraobserver variability for measurements of the longest diameter. Caution should be warranted in reducing radiation dose level below 50% of a conventional CT protocol due to the potentially detrimental impact on the assessment of lesion response in the liver.
Authors: Christiane K Kuhl; Yunus Alparslan; Jonas Schmoee; Bruno Sequeira; Annika Keulers; Tim H Brümmendorf; Sebastian Keil Journal: Radiology Date: 2018-11-06 Impact factor: 11.105