Ex Vivo Histopathological Validation of Optical Frequency Domain Imaging for Diagnosing Intimal and Medial Calcification in a Single Femoropopliteal Lesion.

Optical frequency domain imaging (OFDI) is available to guide atherectomy for severely calcified femoropopliteal lesions in patients with lower extremity artery disease, although its diagnostic accuracy has not been histologically validated. We evaluated the diagnostic capability of OFDI through histopathological co-registration. A total of 38 OFDI cross-sectional images from a single vessel in one patient were successfully co-registered with corresponding histological sections and analyzed. The internal elastic lamina was not identified in 52.6% of images. OFDI detected 60.2% of all calcifications identified histologically, with substantially higher detection rates for intimal than medial calcification (72.3% vs 30.8%). These findings indicate that OFDI provides acceptable assessment of intimal calcification but has limited capability for visualizing the medial layer in severely calcified femoropopliteal lesions. Recognition of these limitations may facilitate more appropriate pre-procedural planning for atherectomy in patients with severely calcified femoropopliteal disease.