Pilot-Scale Evaluation of Partial-Slide Imaging for Detecting Critical Morphological Features (Excluding Parasites):...

This UK-based pilot study explores a hybrid approach integrating virtual (VM) and light microscopy (LM), using partial-slide imaging (PSI) at ×20 magnification (equivalent to approximately ×58 effective output magnification).

This study utilised a 3D Histech Pannoramic MIDI II Slide scanner to digitise 50 peripheral blood smears. PSI was specifically defined by capturing the feathered edge and monolayer regions of the smears. A diverse range of 44 conditions, characterised by distinct morphological features across red blood cell, white blood cell and platelet lineages, was investigated. A comparative analysis between traditional LM and VM was then performed, alongside assessment of scan times and storage requirements, with statistical analyses using Student's t-tests, where a p ≤ 0.05 was considered statistically significant.

Excluding parasites, the critical morphological features were reliably assessed, with diagnostic images from VM judged comparable and adequate to LM: the three subcellular features-Döhle bodies, basophilic stippling and Auer rods-were verified side-by-side, while overall 44 features were assessed using a three-point graded scale. Operationally, PSI at ×20 magnification demonstrated substantial efficiency, with a mean scan time of 4 min 17 s and storage of 1.18 GB per slide, representing statistically significant reductions (p < 0.05) in both scanning time and storage compared to whole-slide imaging.

This pilot-scale study supports a hybrid model, demonstrating that PSI at 20× shows promising feasibility for morphological assessment within a hybrid VM-LM model, but further validation is required to confirm diagnostic equivalence with LM. This study offers significantly reduced scan times and storage requirements compared to whole-slide imaging.