Pulmonary Embolism Scores
Most of the work of a PE pathway happens before the scanner: is imaging the next step, or is a D-dimer enough? The scores below are that decision. The CT tools describe a study that has already been done. They are not substitutes for each other.
Educational reference for qualified professionals. Confirm the result against the source cited on the tool page and against local protocol.
Before the scan
Pretest scores decide whether to image. They do not diagnose embolism, and a low score does not describe the clot burden of a CT that was done anyway.
- Wells Score for Pulmonary EmbolismCalculator
Two-tier and three-tier Wells score for suspected pulmonary embolism.
- Revised Geneva Score for Pulmonary EmbolismCalculator
Revised Geneva score, when the department uses that rule instead of Wells.
- PERC Rule (Pulmonary Embolism Rule-out Criteria)Calculator
Rule-out criteria for a patient who is already low probability. Not a score for everyone.
- Age-Adjusted D-dimer (ADJUST-PE)Calculator
Age-adjusted D-dimer threshold used when the pathway calls for a dimer.
- Suspected acute pulmonary embolismVetting
Which study the clinical question actually needs, including when CTPA is not it.
After a positive study
Severity and burden tools describe a diagnosed embolism. They do not decide whether the CT should have been done.
- PESI / sPESI (Pulmonary Embolism Severity Index)Calculator
PESI and sPESI — clinical severity, not an imaging measurement.
- Qanadli CT Pulmonary Obstruction IndexCalculator
CT obstruction index from the arteries that are blocked.
- RV/LV Diameter Ratio on CTPACalculator
Right-to-left ventricular diameter ratio on the CT that showed the embolism.
- CTPA — Standard Bolus-TrackedProtocol
How a CT pulmonary angiogram is timed and what makes it non-diagnostic.
Questions these pages get
Which score decides whether to do a CTPA?
Wells or revised Geneva, sometimes with PERC when probability is already low, and a D-dimer when the pathway says so. PESI, Qanadli and the RV/LV ratio describe a patient or a scan after the diagnosis is in view. They are the wrong tools for the request.
Where is the protocol?
The CTPA protocol page covers bolus timing, contrast and the failures that produce a non-diagnostic study. The vetting guide covers whether CTPA is the study to request in the first place.