Detection of Cholesterol Crystals in Progressive High-Intensity Plaque With the Use of T1-Weighted Magnetic Resonance Imaging

A 53-year-old man presented to our department with unstable angina pectoris. Coronary computed tomography showed severe stenosis in the middle left anterior descending artery (LAD) (Fig. 1A), mild stenosis with a napkin-ring sign, positive remodelling, and a low-attenuation plaque in the proximal right coronary artery (RCA) (Fig. 1B). Noncontrast T1-weighted magnetic resonance imaging (T1WI MRI) revealed a high-intensity plaque (HIP) in the same RCA lesion (Fig. 1C; Video 1 , view video online). Coronary angiography (CAG) showed severe stenosis in the proximal LAD (Fig. 1D) and a mild plaque in the proximal RCA (Fig. 1E). Therefore, a percutaneous coronary intervention (PCI) was performed in the LAD and statin was started. Six months later, the patient experienced chest pain while exercising. T1WI MRI showed a progression in HIP volume and increased signal intensity of HIP in the RCA lesion compared with the previous encounter (Fig. 1F; Video 2 , view video online). CAG revealed severe stenosis in the proximal RCA, and therefore PCI was performed (Fig. 1G). Intravascular ultrasound (IVUS) detected an attenuated plaque in the target lesion (Fig. 1H), for which a distal protection device was used (Fig. 1I). After balloon dilatation, electrocardiography showed ST-segment elevation in inferior leads and the slow-flow phenomenon was observed. IVUS after stent deployment revealed plaque prolapse through the stent struts (Fig. 1J). After PCI, a large amount of debris was collected in the device filter and cholesterol crystals were identified under a polarising microscope (Fig. 1, K and L). On the following day, the troponin T value increased to 0.216 ng/mL, and periprocedural myocardial injury (PMI) occurred.