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Published on: August 26, 2025
Mandatory adherence to diagnostic protocol increases the yield of CTPA for pulmonary embolism
Stefan Walen1, Erwin de Boer2, Mireille A Edens3
1Department of Pulmonology, Isala, Dr. van Heesweg 2, 8025 AB, Zwolle, The Netherlands. s.walen@isala.nl.
Insights
Mandatory adherence to a diagnostic protocol significantly increased the diagnostic yield of computed tomography pulmonary angiographies (CTPAs) for pulmonary embolism (PE). Previous deep venous thrombosis (DVT) and clinical signs of DVT were associated with a higher likelihood of positive PE findings.
Area of Science:
- Medical Imaging and Diagnostics
- Pulmonary Medicine
- Clinical Protocol Optimization
Background:
- Pulmonary embolism (PE) diagnosis relies on computed tomography pulmonary angiography (CTPA).
- Optimizing diagnostic protocols can improve the accuracy and efficiency of PE detection.
- Previous studies have explored factors influencing CTPA diagnostic yield.
Purpose of the Study:
- To evaluate the impact of mandatory diagnostic protocol adherence on CTPA positive rates for PE.
- To identify clinical factors associated with an increased diagnostic yield of CTPA for PE.
Main Methods:
- A prospective cohort of patients with suspected PE undergoing CTPA was analyzed.
- Physicians were mandated to follow a diagnostic workup including Wells score and D-dimer testing.
- The percentage of positive CTPA scans was compared to a historical cohort.
Main Results:
- A statistically significant increase in positive CTPA scans for PE was observed following protocol implementation (p=0.001).
- Previous deep venous thrombosis (DVT) and clinical signs of DVT were independent predictors of a positive CTPA (ORs 3.22 and 2.71, respectively).
- Chronic obstructive pulmonary disease (COPD) showed a negative association with PE (OR 0.33).
Conclusions:
- Mandatory adherence to a diagnostic protocol effectively enhances the diagnostic yield of CTPA for PE.
- Clinical history of DVT and current signs of DVT are key indicators for PE suspicion.
- Patients with low Wells scores and low D-dimer levels did not present with PE in this cohort.
Objectives:
To determine if mandatory adherence to a diagnostic protocol increases the rate of computed tomography pulmonary angiographies (CTPAs) positive for pulmonary embolism (PE)-the so-called diagnostic yield. Further, we aim to identify factors associated with this diagnostic yield.
Methods:
We included all patients with suspected PE requiring CTPA from 9 January 2014 t0 3 June 2014. The requesting physicians were forced to follow diagnostic workup for PE by calculating a Wells score and, if necessary, determining D-dimer level. The percentage of positive CTPA scans was calculated and compared with our previous cohort (Walen et al. Insights Imaging 2014;5(2):231-236). Odds ratios were calculated as a measure of association between dichotomous variables and CTPA findings.
Results:
Of 250 scans, 74 were positive (29.6 % [95 % CI, 24.3-35.5 %]) and 175 were negative (70 %). The percentage positive scans increased with 6.6 % and the percentage negative scans decreased with 3.1 %. This change was statistically significant (p = 0.001). Independent clinical predictors of diagnostic yield were previous deep venous thrombosis (DVT) (OR, 3.22; p = 0.013) and clinical signs of DVT (OR, 2.71; p = 0.012). Chronic obstructive pulmonary disease (COPD) was negatively associated with PE (OR, 0.33; p = 0.045).
Conclusions:
This study shows that mandatory adherence to a diagnostic protocol increases the yield of CTPA for PE in our centre.
Main Messages:
• Mandatory adherence to diagnostic protocol increases the yield of CTPA for PE • Previous DVT and signs of DVT were associated with a higher yield • No patients with a low Wells score and a low D-dimer had PE.
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