Lung nodule detection in pediatric chest CT: quantitative relationship between image quality and radiologist performance.

Journal Article (Journal Article)

PURPOSE: To determine the quantitative relationship between image quality and radiologist performance in detecting small lung nodules in pediatric CT. METHODS: The study included clinical chest CT images of 30 pediatric patients (0-16 years) scanned at tube currents of 55-180 mA. Calibrated noise addition software was used to simulate cases at three nominal mA settings: 70, 35, and 17.5 mA, resulting in quantum noise of 7-32 Hounsfield Unit (HU). Using a validated nodule simulation technique, lung nodules with diameters of 3-5 mm and peak contrasts of 200-500 HU were inserted into the cases, which were then randomized and rated independently by four experienced pediatric radiologists for nodule presence on a continuous scale from 0 (definitely absent) to 100 (definitely present). The receiver operating characteristic (ROC) data were analyzed to quantify the relationship between diagnostic accuracy (area under the ROC curve, AUC) and image quality (the product of nodule peak contrast and displayed diameter to noise ratio, CDNR display). RESULTS: AUC increased rapidly from 0.70 to 0.87 when CDNR display increased from 60 to 130 mm, followed by a slow increase to 0.94 when CDNR display further increased to 257 mm. For the average nodule diameter (4 mm) and contrast (350 HU), AUC decreased from 0.93 to 0.71 with noise increased from 7 to 28 HU. CONCLUSIONS: We quantified the relationship between image quality and the performance of radiologists in detecting lung nodules in pediatric CT. The relationship can guide CT protocol design to achieve the desired diagnostic performance at the lowest radiation dose.]

Full Text

Duke Authors

Cited Authors

  • Li, X; Samei, E; Barnhart, HX; Gaca, AM; Hollingsworth, CL; Maxfield, CM; Carrico, CWT; Colsher, JG; Frush, DP

Published Date

  • May 2011

Published In

Volume / Issue

  • 38 / 5

Start / End Page

  • 2609 - 2618

PubMed ID

  • 21776798

International Standard Serial Number (ISSN)

  • 0094-2405

Digital Object Identifier (DOI)

  • 10.1118/1.3582975


  • eng

Conference Location

  • United States