TY - JOUR JO - EuroIntervention TI - Tangential signal dropout artefact in optical frequency domain imaging AB - <p><strong>Background:</strong> Tangential signal dropout (TSD), which occurs when the optical frequency domain imaging (OFDI) beam strikes the vessel wall under a glancing angle and travels almost parallel to the vessel wall, is the most important imaging artefact leading to the erroneous diagnosis of lipid-rich plaques.</p> <p><strong>Aims:</strong> This study aimed to evaluate the OFDI artefact of TSD, which mimics the appearance of lipid-rich plaque and macrophage (M&oslash;) infiltration.</p> <p><strong>Methods:</strong> A total of 1,019 histological cross-sections from 23 autopsy hearts were matched with the corresponding OFDI images. Of these, 232 OFDI cross-sections that contained signal-poor regions with diffuse borders were classified as lipid-rich plaques. The angle &theta; was calculated between the OFDI beam that strikes the edge of the luminal surface of the low-intensity region and that which strikes the surface line of the low-intensity region.</p> <p><strong>Results:</strong> On histological evaluation, 182 (78%) cross-sections were classified as histologically lipidic/M&oslash; infiltration, while the remaining 50 (22%) cross-sections were classified as histologically non-lipidic/M&oslash; infiltration. The angle &theta; was significantly smaller in the non-lipidic/M&oslash; infiltration group than in the lipidic/M&oslash; infiltration group (12&plusmn;6&deg; versus 37&plusmn;14&deg;, p&lt;0.001). Receiver operating curve analysis revealed that the optimal cut-off value of the incident angle for predicting TSD was 23&deg; with an area under the curve of 0.98.</p> <p><strong>Conclusions:</strong> When the OFDI imaging beam strikes the tissue at an angle &theta;&lt;23&deg;, TSD artefact could occur. To eliminate image misinterpretation, our findings suggest that the OFDI catheter geometry should be considered for the accurate diagnosis of lipid-rich plaques and M&oslash; infiltration.</p> AU - Shibutani Hiroki AU - Fujii Kenichi AU - Kawakami Rika AU - Imanaka Takahiro AU - Kawai Kenji AU - Tsujimoto Satoshi AU - Matsumura Koichiro AU - Otagaki Munemitsu AU - Morishita Shun AU - Hashimoto Kenta AU - Hirota Seiichi AU - Shiojima Ichiro VL - 17 IS - 4 Y1 - 20/07/2021 Y1 - 2021 DOI - 10.4244/EIJ-D-20-00014 SP - e326 EP - e331 KW - optical coherence tomography KW - clinical research KW - stable angina PB - Europa Digital & Publishing SE - Coronary interventions UR - https://eurointervention.pcronline.com/article/tangential-signal-dropout-mimicking-the-appearance-of-lipid-rich-plaques-and-macrophage-infiltration-on-optical-frequency-domain-imaging SN - 1774-024X ER -