Evaluation of inter-observer agreement between radiologists and students in the detection of breast lesions in mammograms

Abstract

Introduction: Mammography screening is relevant for women at risk for breast cancer.

Objective: To evaluate the inter-observer agreement between a breast radiologist and medical students of a university in the province of Tungurahua, Ecuador, in the detection of breast lesions in mammograms.

Methods: The study was relational, cross-sectional, observational, analytical and prospective. The study population consisted of four medical students and a radiologist specializing in mammography. SPSS statistical software was used and Cohen's Kappa coefficient was calculated. It was hypothesized that there was inter-observer agreement between the breast radiologist and the medical students in the categorization of mammographic findings.

Results: In 19 % of cases where the radiologist reported the mammogram as negative, at least one of the students concurred with that impression. In 28% of the cases categorized as probably benign by the radiologist, all students agreed in assigning that category of suspicion. There was a lower degree of agreement in the category of benign lesion, indicating that in several of these cases the students tended to over or underestimate the abnormality identified by the specialist. According to the Kappa Coefficient, the strength of diagnostic agreement was 0.893 (p<0.001). The results of Pearson's Chi-square test and linear by linear association were highly significant (p<0.001).

Conclusions: There was an adequate correspondence of the assigned diagnostic categories between the radiologist's reading and that of the medical students.