Radiomics-Based Carotid Ultrasound Identifies Patterns Associated with Severe Coronary Calcification in the Absence of Carotid Plaque

BackgroundTo assess whether radiomics analysis of carotid ultrasound (CUS) can identify texture features associated with severe coronary artery calcification, even in individuals without carotid plaque. MethodsThis study included 105 participants with coronary artery calcium score (CACS) > 400 and no carotid plaque, matched by age and sex to 105 controls with CACS=0. B-mode CUS images of the bilateral distal common carotid arteries (CCA) were analyzed, with 1-cm longitudinal regions of interest extending from the lumen to the adventitia. Radiomic features were extracted from each frame, filtered by variance and correlation, and ranked using bootstrap-based XGBoost feature importance (FI) and evaluated on internal and external datasets. ResultsAmong 700 extracted features, the final retained features were reproducible: 8 (right) and 11 (left) for CACS=0, and 7 (right) and 10 (left) for CACS > 400 (all p < 0.05). Group-specific features, observed only in the CACS 0 or CACS > 400 group, included 90th Percentile (CACS=0: right distal CCA, FI=0.030; left distal CCA, FI=0.025) and Run Entropy (CACS > 400: right distal CCA, FI=0.046; left distal CCA, FI=0.038). Shared features such as Long Run Emphasis, Dependence Non-Uniformity, and Entropy were consistently observed across both groups and sides (FI=0.023-0.029), with Dependence Non-Uniformity consistent in the left distal CCA across both groups and datasets. ConclusionsAlthough no plaque was detected on CUS, radiomics can identify ultrasound texture patterns associated with severe coronary calcification. This approach may improve detection of high-risk individuals who would otherwise be classified as low-risk by CUS alone. Graphic AbstractTexture-Based Radiomics of Carotid Ultrasound Reveals Severe Coronary Calcification. (A), Imaging modalities and study population: Adults undergoing health screenings at tertiary hospitals in City A and City B (2018-2022) who received same-day carotid ultrasound and CACS CT. After excluding plaque, CVD history, and poor image quality, 105 plaque-free participants with CACS > 400 were identified and age- and sex-matched to 105 plaque-free participants with CACS = 0. (B), Radiomics pipeline: carotid ultrasound images were segmented, preprocessed, filtered, and processed for feature extraction and selection, yielding reproducible texture features. (C), Radiomics feature maps: representative examples of plaque-free carotid ultrasound in patients with CACS = 0 and CACS >400. Entropy and dependence non-uniformity maps demonstrate distinct texture patterns associated with severe coronary calcification. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=128 SRC="FIGDIR/small/25337136v1_ufig1.gif" ALT="Figure 1"> View larger version (51K): org.highwire.dtl.DTLVardef@eb2b93org.highwire.dtl.DTLVardef@179c26aorg.highwire.dtl.DTLVardef@caf446org.highwire.dtl.DTLVardef@6b2325_HPS_FORMAT_FIGEXP M_FIG C_FIG