Observer accuracy in the detection of pulmonary nodules on CT: effect of cine frame rate

To assess the effect of cine frame rate on the accuracy of the detection of pulmonary nodules at computed tomography (CT).

CT images of 15 consecutive patients with (n = 13) or without (n = 2) pulmonary metastases were identified. Initial assessment by two thoracic radiologists provided the "actual" or reference reading. Subsequently, 10 radiologists [board certified radiologists (n = 4) or radiology residents (n = 6)] used different fixed cine frame rates for nodule detection. Within-subjects analysis of variance (ANOVA) was used to evaluate the data.

Eighty-nine nodules were identified by the thoracic radiologists (median 8, range 0-29 per patient; median diameter 9 mm, range 4-40 mm). There was a non-statistically significant trend to reduced accuracy at higher frame rates (p=0.113) with no statistically significant difference between experienced observers and residents (p = 0.79).

The accuracy of pulmonary nodule detection at higher cine frame rates is reduced, unrelated to observer experience.