Nancy A Obuchowski1. 1. Department of Quantitative Health Sciences/Wb4, and the Imaging Institute, The Cleveland Clinic, Cleveland, OH 44195, USA. obuchon@ccf.org
Abstract
RATIONALE AND OBJECTIVES: Multireader, multicase (MRMC) receiver-operating characteristic studies often require large numbers of patients, readers, and reader interpretations. The objective of this work is to evaluate a new "mixed" MRMC study design that reduces the number of reader interpretations. MATERIALS AND METHODS: As compared to the traditional MRMC design, the number of reader interpretations and the number of cases that must be truth-verified for the new mixed design was evaluated theoretically and empirically for various correlation values and sample sizes. RESULTS: For large MRMC studies, the new mixed design offers a substantial savings in the number of reader interpretations if the magnitude of the difference in between-reader correlations is not zero. For example, compared to a traditional design with 20 readers, 200 total cases, and a difference in between-reader correlations of 0.05, the newly proposed mixed design requires each reader to interpret only 132 cases, but at a cost of truth-verifying an additional 64 cases. CONCLUSIONS: The mixed design can reduce the number of cases that readers need to interpret and the overall duration of a study, but at a cost in terms of the number of cases that must be truth-verified. The mixed design is particularly useful for studies where the condition being detected is not rare and patients routinely undergo the gold standard assessment.
RATIONALE AND OBJECTIVES: Multireader, multicase (MRMC) receiver-operating characteristic studies often require large numbers of patients, readers, and reader interpretations. The objective of this work is to evaluate a new "mixed" MRMC study design that reduces the number of reader interpretations. MATERIALS AND METHODS: As compared to the traditional MRMC design, the number of reader interpretations and the number of cases that must be truth-verified for the new mixed design was evaluated theoretically and empirically for various correlation values and sample sizes. RESULTS: For large MRMC studies, the new mixed design offers a substantial savings in the number of reader interpretations if the magnitude of the difference in between-reader correlations is not zero. For example, compared to a traditional design with 20 readers, 200 total cases, and a difference in between-reader correlations of 0.05, the newly proposed mixed design requires each reader to interpret only 132 cases, but at a cost of truth-verifying an additional 64 cases. CONCLUSIONS: The mixed design can reduce the number of cases that readers need to interpret and the overall duration of a study, but at a cost in terms of the number of cases that must be truth-verified. The mixed design is particularly useful for studies where the condition being detected is not rare and patients routinely undergo the gold standard assessment.
Authors: Brandon D Gallas; Heang-Ping Chan; Carl J D'Orsi; Lori E Dodd; Maryellen L Giger; David Gur; Elizabeth A Krupinski; Charles E Metz; Kyle J Myers; Nancy A Obuchowski; Berkman Sahiner; Alicia Y Toledano; Margarita L Zuley Journal: Acad Radiol Date: 2012-02-03 Impact factor: 3.173
Authors: Nicholas Petrick; Berkman Sahiner; Samuel G Armato; Alberto Bert; Loredana Correale; Silvia Delsanto; Matthew T Freedman; David Fryd; David Gur; Lubomir Hadjiiski; Zhimin Huo; Yulei Jiang; Lia Morra; Sophie Paquerault; Vikas Raykar; Frank Samuelson; Ronald M Summers; Georgia Tourassi; Hiroyuki Yoshida; Bin Zheng; Chuan Zhou; Heang-Ping Chan Journal: Med Phys Date: 2013-08 Impact factor: 4.071
Authors: M Voth; U I Attenberger; A Luckscheiter; S Haneder; T Henzler; S O Schoenberg; C Schwenke; H J Michaely Journal: Eur Radiol Date: 2010-10-23 Impact factor: 5.315