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Interobserver agreement for the direct and indirect signs of pulmonary embolism evaluated using contrast enhanced
Nanae Tsuchiya1,2,3, Donald G Benson1,4,3, Colin Longhurst5,3
1Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States.
Background:
Accurate diagnosis of pulmonary embolism (PE) using contrast enhanced MRA (CE-MRA) requires awareness of both the direct and indirect findings of PE.
Purpose:
To evaluate reader agreement of the direct and indirect findings of PE on CE-MRA.
Methods:
We evaluated pulmonary artery diameter, right ventricle/left ventricle ratio, and clot/vessel lumen signal intensity ratio. Also, eight direct and eight indirect findings of PE were interpreted twice by two radiologists with different experience levels. The prevalence, and intra- and inter-reader agreement for the direct and indirect findings of PE were recorded. Statistical analysis of the measurements was assessed using intraclass correlation while Cohen's kappa test determined inter- and intra-reader agreement.
Results:
We reviewed 66 positive CE-MRA exams, 10 of which cases were used for training. The largest PE for each of the remaining 56 cases (40 woman) were included in this analysis (38.9 ± 19.7 (mean age (years) ± S.D.)). The highest interobserver agreement for the direct findings were vessel cutoff (κ = 0.52, 95 % CI = (0.30, 0.74), p < .0001) and bright clot (κ = 0.51, 95 % CI = (0.26, 0.78), p = .0001). The highest interobserver agreement for the indirect findings were for atelectasis (κ = 0.67, 95 % CI = (0.49, 0.87), p < .0001), pleural effusions (κ = 0.56, 95 % CI = (0.32, 0.79), p = 0001) and blank slate sing (κ = 0.56, 95 % CI = (0.18, 0.94), p < .0001).
Conclusion:
The indirect findings of atelectasis and pleural effusion had better interobserver reproducibility than the direct findings of vessel cutoff and bright clot. The intraobserver reproducibility of the direct and indirect findings is dependent on experience level.
Summary Statement:
Using contrast enhanced magnetic resonance angiography for the diagnosis of pulmonary embolism, the indirect findings of atelectasis and pleural effusion had better interobserver reproducibility than the direct findings of vessel cutoff and bright clot.
Insights
Radiologists showed better agreement on indirect signs of pulmonary embolism (PE) like atelectasis and pleural effusion compared to direct signs such as vessel cutoff on contrast-enhanced MRA. Reader experience influences reproducibility of these findings.
Area of Science:
- Radiology
- Medical Imaging
- Cardiovascular Imaging
Background:
- Accurate diagnosis of pulmonary embolism (PE) using contrast-enhanced magnetic resonance angiography (CE-MRA) relies on recognizing both direct and indirect imaging findings.
- Understanding reader agreement on these findings is crucial for consistent diagnostic performance.
Purpose of the Study:
- To evaluate the inter-reader and intra-reader agreement for direct and indirect findings of PE on CE-MRA.
- To assess the reproducibility of specific imaging markers used in PE diagnosis via CE-MRA.
Main Methods:
- Two radiologists with varying experience levels independently interpreted direct and indirect PE findings on 56 CE-MRA exams.
- Quantitative measurements included pulmonary artery diameter and ventricle/clot ratios.
- Statistical analysis utilized intraclass correlation for measurements and Cohen's kappa for agreement.
Main Results:
- Highest interobserver agreement for direct findings: vessel cutoff (κ=0.52) and bright clot (κ=0.51).
- Highest interobserver agreement for indirect findings: atelectasis (κ=0.67), pleural effusions (κ=0.56), and blank slate sign (κ=0.56).
- Intraobserver agreement varied based on reader experience level.
Conclusions:
- Indirect findings of atelectasis and pleural effusion demonstrated superior interobserver reproducibility compared to direct findings like vessel cutoff and bright clot.
- The reproducibility of both direct and indirect PE findings on CE-MRA is influenced by the radiologist's experience level.
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