Summary: Low-dose CT scans reduce the sensitivity of CAD systems in detecting small lung nodules in pediatric patients, especially for nodules smaller than 5 mm, according to a study comparing standard and low-dose scans.

Key Takeaways

  • Reduced Sensitivity in Low-Dose Scans: Low-dose CT protocols significantly reduce the sensitivity of CAD systems in detecting small lung nodules in pediatric patients, particularly for nodules smaller than 5 mm.
  • FlyerScan and MONAI Performance: Both FlyerScan and MONAI CAD systems showed lower detection rates on low-dose scans compared to standard-dose scans, with FlyerScan detecting 66.8% of nodules on low-dose and MONAI detecting 62.3%.
  • Importance of Caution: The findings highlight the need for caution when using low-dose CT in combination with CAD systems in pediatric imaging to avoid missing smaller nodules.

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Caution is advised when using low-dose CT protocols with computer-aided detection (CAD) systems to identify small lung nodules in pediatric patients. This warning comes from an accepted manuscript in the American Journal of Roentgenology (AJR).

“Two lung-nodule CAD systems showed reduced sensitivity on low-dose compared to standard-dose pediatric CT scans performed on the same patients,” wrote Russell C. Hardie, PhD, a professor in the department of electrical and computer engineering at the University of Dayton in Ohio. “The reduced detection was more pronounced for nodules smaller than 5 mm.”

Standard vs. Low-Dose Pediatric CT Scans

The study analyzed 73 patients (32 female, 41 male, mean age 14.7 years) who underwent both standard and low-dose chest CT scans from November 2018 to August 2020. Pediatric radiologists annotated lung nodules as a reference standard, and two CAD systems—FlyerScan and MONAI—were tested on these scans. The systems were trained using adult data and evaluated for their ability to detect nodules measuring 3-30 mm, at two false-positives per scan.

FlyerScan detected 76.9% of nodules on standard-dose scans and 66.8% on low-dose scans. MONAI detected 67.6% on standard-dose scans and 62.3% on low-dose scans.

Featured image: 12-year-old male patient who underwent chest CT due to hepatocellular carcinoma.