Pulmonary embolism (PE) is a threatening clinical entity. The estimated annual incidence worldwide is approximately of 1 per 1000 people and up to 20% of people diagnosed with acute PE die in the next 90 days. Risk stratification of patients with suspected acute PE is mandatory for determining the appropriate approach and it is based on clinical symptoms and signs of haemodynamic instability. The most commonly encountered symptoms are dyspnoea, chest pain, presyncope or syncope, haemoptysis. Also, it is important to evaluate risk factors that can increase the probability of a PE event, that can be genetic (like thrombolphilia, mutation of Leiden V, ect..) or acquired (like a prolongued immobilization, malignancy, recent orthopaedic surgery, ect..) [table] 1. 

The most straightforward diagnostic algorithms for suspected PE—with and without haemodynamic instability— are presented in [fig] 1. In case of haemodynamic instability, after a fast evaluation with transthoracic ecocardiosonography, the patient is redirected either to CTPA (if the scanner is immediately available) or to treatment for supected high-risk PE. In case of a patient hemodynamically stable, clinical suspicion and risk stratification are the crucial steps to an optimal management. After a correct clinical assessment, validated pre-test systems like revised Geneva Score [fig] 2, modified Wells Score [fig] 3, and Pulmonary Embolism Rule-out Criteria (PERC) [fig] 4 are useful tools to direct the patient towards CTPA or D-Dimer test. 

CTPA is the method of choice for imaging pulmonary vessels [fig] 5 in patients with suspected PE. It is readily available, noninvasive, it has short acquisition time and the possibility to grant alternative diagnoses, excellent performance (83% sensitivity, 96% specificity). The number of CTPA is on the rise, especially after COVID-19 pandemic mostly due to the increased number of biologically and radiobiologically proving examinations and to the awareness about pulmonary embolism and its correlated risks. 

In our retrospective study, we considered 500 patients in one-year period (January 2022 – January 2023) that underwent CTPA with the clinical suspicion of pulmonary embolism. The patients were divided in groups based on the concordance with one of most impactful clinical stratification systems and an evaluation on the most impactful clinical features leading to correct stratification was conducted.