AI can measure the right ventricle on CTPA, but the RVD/LVD ratio is where it struggles

AI can measure the right ventricle on CTPA, but the RVD/LVD ratio is where it struggles

A Real-World Clinical Study on Computed Tomography Pulmonary Angiography-Based Artificial Intelligence-Driven Risk Stratification in Pulmonary Embolism

Journal of Thoracic Imaging, 2026

Abstract

Purpose

To evaluate the efficacy of a computed tomography pulmonary angiography (CTPA)-based artificial intelligence system for use in the clinical setting to stratify the risk of pulmonary embolism (PE).

Materials and Methods

This study enrolled 115 patients diagnosed with PE based on positive CTPA reports at our institution between January 1 and October 10, 2023. Cases were classified as relatively high-risk or low-risk according to the 2019 ESC Guidelines. Two radiologists independently and blindly measured risk-related imaging parameters, including main pulmonary artery diameter (MPAD), ascending aortic diameter (AAD), right and left ventricular diameters (RVD, LVD), the right-to-left ventricular diameter ratio (RVD/LVD ratio), pulmonary artery obstruction index (PAOI), and pulmonary embolism volume (PEV). These results were compared with those from the automated artificial intelligence (AI) system to assess consistency.

Results

The agreement (intraclass correlation coefficients, ICCs) of MPAD, AAD, RVD, PAOI, LVD, and RVD/LVD ratio between AI system and manual measurements were 0.94, 0.79, 0.78, 0.80, 0.54, and 0.48, respectively. Among the AI-extracted covariates, an RVD/LVD ratio >1.2 showed good performance in identifying relatively high-risk PE cases, with an area under the curve (AUC) of 0.771. The AI model incorporating all covariates achieved an AUC of 0.848 for classifying high-risk PE.

Conclusions

The CTPA-based AI system can rapidly extract the key imaging parameters relevant to PE risk stratification in real-world clinical settings, significantly reducing the CTPA interpretation time and improving evaluation efficiency.

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