Human carotid plaque risk imaging using multiparametric photoacoustic and ultrasound fusion (hCAPRI)

Assessing the risk of carotid plaque rupture remains limited because current imaging methods cannot provide both plaque composition and structural information in real time. Here, we present human carotid plaque risk imaging (hCAPRI), a multiparametric photoacoustic and ultrasound (PA/US) fusion method for real-time carotid plaque assessment. hCAPRI combines PA imaging for detecting intraplaque hemorrhage (IPH) with US imaging for evaluating the plaque structure. PA imaging measured IPH size and methemoglobin content, while US imaging assessed stenosis severity, calcification, and plaque thickness. Combining these PA/US parameters, we compute an hCAPRI score. In 171 carotid arteries (CAs) from 120 patients, hCAPRI revealed the relationships among the PA/US parameters. In 36 CAs validated with magnetic resonance imaging (MRI), hCAPRI showed high agreement with MRI. The hCAPRI score achieved 89% sensitivity and 84% specificity for high-risk plaque classification. hCAPRI offers a low-cost, real-time, and contrast-free approach for carotid plaque risk imaging.