Spiral CT of pulmonary nodules: interobserver variation in assessment of lesion size

Abstract

The aim of this study was to assess interobserver variability in size determination of pulmonary nodules at spiral CT. Twenty-three patients with known pulmonary nodules (diameter 2-40 mm, mean diameter 7 mm) underwent spiral chest CT (collimation 5 mm, pitch 1). Images were reconstructed at 3- and 5-mm intervals (RI). Hard copies were analyzed by two radiologists who recorded every nodule with regard to location, diagnostic confidence ("definite," "probable") and nodule size in increments of 1 mm with specific attention to correct classification into one of three size classes (< or = 5 mm, 6-10 mm, > 10 mm). Interobserver variability was determined with Pearson's correlation coefficient and kappa measure. Of a total of 286 nodules, 103 nodules were found accordingly by both readers at 3 mm RI, and 96 at 5 mm RI. There was a good correlation of measurements (in millimeters) between both readers (Pearson's correlation coefficient: 0.89-0.95). Interobserver variability in categories was good at both reconstruction intervals (kappa: 0.61 at 3 mm, 0.74 at 5 mm RI) and very good (0.81) at 5 mm RI when uncertain nodules were excluded. Spiral CT allows reproducible size determination of pulmonary nodules as shown by good interobserver agreement in exact size measurement and categorization into three size classes.

No Benefit for Consensus Double Reading at Baseline Screening for Lung Cancer with the Use of Semiautomated Volumetry Software

“…The interobserver agreement was moderate to substantial, and potential for considerable improvement existed. Similar results have been reported in clinical settings with a relatively high interobserver variability for the detection and characterization of pulmonary nodules (16)(17)(18). Theoretically, the more nodules identifi ed, the higher the probability to detect cancer.…”

“…Interobserver variability in reader performance for the detection and characterization of pulmonary nodules has been found to be relatively high with chest computed tomographic (CT) imaging both in the clinical setting and in lung cancer screening (18)(19)(20)(21). So far, the effect of double reading on the cancer detection in lung cancer CT screening has, to our knowledge, not been…”

Interobserver and Intraobserver Variability among Measurements of FDG PET/CT Parameters in Pulmonary Tumors

“…In the literature, several studies have reported good interobserver and intraobserver agreement of tumor size measurements (20,21). However, some other studies have demonstrated substantial variation (22,23).…”

Assessment of Interobserver Reproducibility in Quantitative 18F-FDG PET and CT Measurements of Tumor Response to Therapy

“…Presently, the major response criteria for solid tumors, Response Evaluation Criteria in Solid Tumors (RECIST) (1) and the World Health Organization criteria (2), primarily rely on changes in tumor size on anatomic imaging. Although several studies have demonstrated reasonably good intra-and interobserver reproducibility of tumor size measurements (3,4), others have demonstrated that inconsistent tumor size measurements can lead to incorrect interpretations of tumor response (5,6).…”