Fig.1. Study flowchart.

CN, calcified nodule; IVUS, intravascular ultrasound; OCT, optical coherence tomography; OFDI, optical frequent domain imaging; RA, rotational atherectomy.

CN, calcified nodule; IVUS, intravascular ultrasound; OCT, optical coherence tomography; OFDI, optical frequent domain imaging; RA, rotational atherectomy.