Lung scan interpretation: effect of different observers and different criteria

Area of Science:

• Nuclear Medicine
• Radiology
• Medical Imaging

Background:

• Physicians interpret lung scintigrams using various criteria (McNeil, Biello et al., or integrated approaches).
• Interobserver variability and comparative effectiveness of these interpretation schemes are not well-established.

Purpose of the Study:

• To assess interobserver variation in lung scintigram interpretation.
• To compare the diagnostic performance of different interpretation criteria (McNeil, Biello, and modified criteria).

Main Methods:

• Two experienced nuclear medicine physicians independently reviewed 98 lung scintigrams with angiographic correlation.
• Objective descriptions of perfusion, ventilation, and radiographic abnormalities were recorded.
• Scans were categorized using McNeil and Biello criteria, and a modified criteria set.

Main Results:

• Significant interobserver variation was noted in describing scan abnormalities.
• No statistically significant differences were found between receiver operating characteristic (ROC) curves for individual readers or criteria sets.
• Biello and modified criteria reduced indeterminate classifications without compromising accuracy.
• A significant difference in overall accuracy was observed between the two study years.

Conclusions:

• Current lung scintigram interpretation criteria exhibit substantial interobserver variation.
• No single criterion set demonstrated clear superiority in diagnostic accuracy.
• Modified and Biello criteria may offer advantages in reducing indeterminate interpretations.
• Year-to-year variations in accuracy highlight potential issues in retrospective studies.