Abstract
Optical coherence tomography angiography (OCTA) images retinal blood flow, giving capillary-perfusion and foveal-avascular-zone biomarkers that grade diabetic-retinopathy ischemia. Because OCTA hardware is less common than structural OCT, recent work synthesizes it from OCT, reporting strong reconstruction (3D PSNR >31 dB, SSIM >0.9). We ask not whether the synthetic image looks similar, but whether it supports the measurements OCTA is acquired for. A frozen real-OCTA segmenter, applied as a probe to two synthesizers (XOCT, TransPro), shows downstream Dice falling with structural fineness: large vessels survive (0.862 → 0.831) while the fine capillary network collapses (0.798 → 0.635, five times the large-vessel loss; paired Wilcoxon p < 10−3), TransPro worse throughout. Matched-blur and alignment controls show this detail is neither blurred away nor displaced, but wrongly connected. Retrained on a private Spectralis dataset, neither synthesizer reproduces the neovascular lesion (qualitative, n=3). Reconstruction fidelity is not clinical utility; we establish downstream-task fidelity as the evaluation OCT-to-OCTA synthesis needs.
Links to Paper and Supplementary Materials
Main Paper (Open Access Version): https://papers.miccai.org/miccai-2026-sat/paper/OMIA_042.pdf
SharedIt Link: Not yet available
SpringerLink (DOI): Not yet available
Supplementary Material: https://papers.miccai.org/miccai-2026-sat/supp/OMIA_042_supp.pdf
Link to Open Review
Open Review Page: https://openreview.net/forum?id=dC8wUbKgnU
BibTex
@InProceedings{CheMic_In_MICCAISAT2026,
author = { Chertok, Michael AND Tiosano, Alon AND Gal-Or, Orly AND Kramarski, Lior AND Baharav Shlezinger, Einav AND Bahar, Irit AND Wolf, Lior},
title = { { In Defense of OCTA: The Reconstruction-Utility Gap in OCT-to-OCTA Synthesis } },
booktitle = {Medical Image Computing and Computer Assisted Intervention -- MICCAI 2026 Workshops and Challenges},
year = {2026},
publisher = {Springer Nature Switzerland},
volume = {LNCS 17270},
month = {pending},
page = {pending}
}