Cinematic Rendering as an Adjunct in Coronary CT Angiography: A Case Series on Myocardial Bridging and Intracameral-Appearing Coronary Courses

Background/Objectives: Myocardial bridging is a common anatomic variant in which an epicardial coronary artery takes an intramyocardial course. A true intracameral, or intracavitary, coronary course is rare. On coronary CT angiography (CTA), multiplanar and curved planar reformations answer most of these questions, but some cases stay equivocal because of partial-volume effects, cardiac motion, and loss of depth cues. A vessel next to a thin or fat-infiltrated wall can also mimic an intracameral course. Cinematic rendering (CR) is a photorealistic three-dimensional post-processing method that uses Monte Carlo path tracing with global illumination to reproduce natural depth and soft-tissue shading. Methods: In this retrospective, single-center, four-patient case series, we describe patients in whom CR was used alongside standard two-dimensional and reformatted CTA after the planar reconstructions had been read as equivocal. The cases were purposively selected as illustrative examples rather than consecutively enrolled, and the report is intended to be hypothesis-generating. Results: In two patients with left anterior descending (LAD) myocardial bridging, CR showed the tunneled segment with depth and was useful for discussion with referring clinicians and for teaching. In two patients whose coronary segment looked intracameral on planar images, CR showed intact overlying myocardium, which favored an intramyocardial course over chamber entry. Conclusions: In these selected patients, CR did not add anatomic information that was unavailable on expert reformations. It appeared to improve perceived depth and reader confidence in these equivocal cases and was useful for communication and teaching; no quantitative image analysis or formal reader study was performed. Because this is a small, retrospective case series without a comparison group, these observations are illustrative and hypothesis-generating and cannot be extrapolated to coronary CTA in general; prospective comparative studies are needed to determine whether CR adds diagnostic value over standard reconstructions.