Computer-aided diagnosis system for bone scintigrams from Japanese patients: importance of training database

Hiroyuki Horikoshi,Akihiro Kikuchi,Lars Edenbrandt,Karl Sjöstrand,Masahisa Onoguchi

doi:10.1007/s12149-012-0620-5

Abstract

AimComputer-aided diagnosis (CAD) software for bone scintigrams have recently been introduced as a clinical quality assurance tool. The purpose of this study was to compare the diagnostic accuracy of two CAD systems, one based on a European and one on a Japanese training database, in a group of bone scans from Japanese patients.MethodThe two CAD software are trained to interpret bone scans using training databases consisting of bone scans with the desired interpretation, metastatic disease or not. One software was trained using 795 bone scans from European patients and the other with 904 bone scans from Japanese patients. The two CAD softwares were evaluated using the same group of 257 Japanese patients, who underwent bone scintigraphy because of suspected metastases of malignant tumors in 2009. The final diagnostic results made by clinicians were used as gold standard.ResultsThe Japanese CAD software showed a higher specificity and accuracy compared to the European CAD software [81 vs. 57 % (p < 0.05) and 82 vs. 61 % (p < 0.05), respectively]. The sensitivity was 90 % for the Japanese CAD software and 83 % for the European CAD software (n.s).ConclusionThe CAD software trained with a Japanese database showed significantly higher performance than the corresponding CAD software trained with a European database for the analysis of bone scans from Japanese patients. These results could at least partly be caused by the physical differences between Japanese and European patients resulting in less influence of attenuation in Japanese patients and possible different judgement of count intensities of hot spots.

Highlights

Patients with prostate or breast cancer often have bone metastases, and the bone metastases of the primary carcinomas may greatly affect the management and prognosis of the patient, so the diagnosis of metastatic disease is important [1,2,3]
The purpose of this study was to compare the diagnostic accuracy of two Computer-aided diagnosis (CAD) systems, one based on a European and one on a Japanese training database, in a group of bone scans from Japanese patients
The Japanese CAD software showed a higher specificity and accuracy compared to the European CAD software [81 vs. 57 % (p \ 0.05) and 82 vs. 61 % (p \ 0.05), respectively]

Summary

Introduction

Patients with prostate or breast cancer often have bone metastases, and the bone metastases of the primary carcinomas may greatly affect the management and prognosis of the patient, so the diagnosis of metastatic disease is important [1,2,3]. The interpretation of bone scans and other diagnostic images are generally made visually as a pattern recognition task where for example the accumulation of a radiopharmaceutical is assessed. This type of task is subjective and largely dependent on the experience of the interpreter. CAD software has been developed for mammography, colonography and myocardial perfusion scintigrams [4,5,6,7]. Lindahl et al [9] reported that physicians improved their diagnostic capability significantly by the use of CAD software in for the analysis of myocardial perfusion scintigrams

Objectives

Methods

Results

Conclusion