Ann Lab Med 2017; 37(6): 499-504
Multicenter Evaluation of an Image Analysis Device (APAS): Comparison Between Digital Image and Traditional Plate Reading Using Urine Cultures
John Glasson, M.S.1, Rhys Hill, B.S.1,2, Michael Summerford, B.S.1, Dianne Olden, Ph.D.3, Fotula Papadopoulos, B.S.4, Stephen Young, Ph.D.5, and Steven Giglio, Ph.D.1
LBT Innovations Ltd.1, Adelaide, Australia; Australian Centre for Visual Technologies2, University of Adelaide, Adelaide, Australia; Australian Clinical Laboratories (formerly Healthscope Pathology)3, Clayton, Australia; SydPath4, St Vincent’s Pathology, Darlinghurst, Australia; Tricore Reference Laboratories5, Albuquerque, NM, USA
Corresponding author: Steven Giglio
LBT Innovations Ltd., Level 1, 300 Flinders Street, Adelaide, SA 5000, Australia
Tel: +61-8-8470-6818 Fax: +61-8-8223-1775 E-mail:
Received: October 25, 2016; Revised: January 9, 2017; Accepted: June 20, 2017; Published online: November 1, 2017.
© Korean Society for Laboratory Medicine. All rights reserved.

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Background: The application of image analysis technologies for the interpretation of microbiological cultures is evolving rapidly. The primary aim of this study was to establish whether the image analysis system named Automated Plate Assessment System (APAS; LBT Innovations Ltd., Australia) could be applied to screen urine cultures. A secondary aim was to evaluate differences between traditional plate reading (TPR) and the reading of cultures from images, or digital plate reading (DPR).
Methods: A total of 9,224 urine samples submitted for culture to three clinical laboratories, two in Australia and one in the USA, were included in the study. Cultures were prepared on sheep blood and MacConkey agar plates and read by panels of three microbiologists. The plates were then presented to APAS for image capture and analysis, and the images and results were stored for later review.
Results: Image analysis of cultures using APAS produced a diagnostic sensitivity and specificity of 99.0% and 84.5%, respectively. Colonies were detected by APAS on 99.0% of blood agar plates with growth and on 99.5% of MacConkey agar plates. DPR agreed with TPR for colony enumeration on 92.1% of the plates, with a sensitivity of 90.8% and specificity of 92.8% for case designation. However, several differences in the classification of colony morphologies using DPR were identified.
Conclusions: APAS was shown to be a reliable screening system for urine cultures. The study also showed acceptable concordance between DPR and TPR for colony detection, enumeration, and case designation.
Keywords: Urine cultures, Image analysis, Digital image plate reading

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