Abstract
In low-resource malaria microscopy, a model trained on one smear preparation routinely meets images from another, and how well morphology-based constraints transfer across this acquisition gap is unclear. We study this on real field microscopy from Uganda (Lacuna), asking where encoding measured parasite morphology as a training constraint improves cross-acquisition transfer and where generic regularisation suffices. We present MORPHA, a morphological consistency constraint that derives stage-conditional statistics from the stage-annotated BBBC041 dataset and penalises predictions that deviate from them. Defined uniformly across binary, object-level, and stage-aware regimes without changing the architecture or inference, it shapes training in the binary regime. The detection regime is a mapped boundary. On transfer from thin-smear cells to thick-smear field images, the constraint reduces the binary-classification generalisation drop by 30.8% (F1: 0.578 to 0.699) at negligible within-domain cost and lowers in-distribution calibration error by 49% (ECE: 0.0162 to 0.0082). A content-free control applying the identical constraint to random statistics recovers less of the drop (25.3% vs. 30.8%), indicating that the measured content, rather than constraining alone, contributes to the gain. Two standard confidence regularisers exceed the constraint on raw transfer, locating where morphology adds value and where generic regularisation suffices. We map two deployment-relevant boundaries: thin-smear statistics do not transfer to thick-smear detection (trophozoite ap@0.50 falls to 0.000), and cross-acquisition pseudolabelling fails before filtering applies. Together, these yield a morphology-grounded consistency signal and evidence-based guidance for malaria dataset and model design in low-resource settings.
Links to Paper and Supplementary Materials
Main Paper (Open Access Version): https://papers.miccai.org/miccai-2026-sat/paper/MIRASOL_011.pdf
SharedIt Link: Not yet available
SpringerLink (DOI): Not yet available
Supplementary Material: https://papers.miccai.org/miccai-2026-sat/supp/MIRASOL_011_supp.pdf
Link to Open Review
Open Review Page: https://openreview.net/forum?id=oAEWd7zzCX
BibTex
@InProceedings{IgwFav_MORPHA_MICCAISAT2026,
author = { Igwezeke, Favour Okechukwu AND Ugwuishiwu, Chikodili Helen AND Anozie, Ekenechukwu Lilian AND Emesiani, Joseph Uzochukwu AND Agada, Samuel Ifebuche AND Kama, Mary Ofuru AND Anazodo, Udunna C. AND Zhang, Dong AND Raymond, Confidence AND Iorumbur, Aondona Moses AND Emegoakor, Adaobi Chiazor},
title = { { MORPHA: Morphology-Constrained Training and the Limits of Cross-Acquisition Transfer in Low-Resource Malaria Microscopy } },
booktitle = {Medical Image Computing and Computer Assisted Intervention -- MICCAI 2026 Workshops and Challenges},
year = {2026},
publisher = {Springer Nature Switzerland},
volume = {LNCS 17264},
month = {pending},
page = {pending}
}