Evidence map›Paper›PMID 42032488›Full record

ArticleBMC medical imaging2026

Comparison of multistage and single-stage framework for automated landmark localization and radiologic measurement: a case of the C1-2 complex on cervical spine lateral radiographs.

Wounsuk Rhee, Jeuk Lee, Ihnseok Chae, Beom-Su Kim, Sung Cheol Park, Sam Yeol Chang, Bong-Soon Chang, Hyoungmin Kim

Abstract readComparative Study
In one paragraph

Article in BMC medical imaging, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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2 · The registry

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4 · The record

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5 · Who and what money

Authors and funding

8 authors.

Wounsuk RheeMinistry of Health and Welfare, Government of the Republic of Korea, 13, Doum 4-ro, Sejong, 30113, Republic of Korea.ORCID 0000-0001-7770-5760
Jeuk LeeDepartment of Orthopedic Surgery, Seoul National University Hospital, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
Ihnseok ChaeDepartment of Orthopedic Surgery, Seoul National University Hospital, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
Beom-Su KimDepartment of Orthopedic Surgery, Seoul National University Hospital, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
Sung Cheol ParkDepartment of Orthopedic Surgery, Bumin Hospital Seoul, 389, Gonghang-daero, Gangseo-gu, Seoul, 07590, Republic of Korea.
Sam Yeol ChangDepartment of Orthopedic Surgery, Seoul National University Hospital, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.ORCID 0000-0003-4152-687X
Bong-Soon ChangDepartment of Orthopedic Surgery, Seoul National University Hospital, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.ORCID 0000-0002-8992-2559
Hyoungmin KimHealthcare AI Research Institute, Seoul National University Hospital, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea. hmkhm@snu.ac.kr.ORCID 0000-0002-4500-9653

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundDespite recent advances, applying deep learning to X-rays remains challenging due to the need for substantial downsampling and limited dataset sizes. While multistage frameworks have been proposed to promote stable performance, their advantages over single-stage designs remain unclear. This study aims to systematically compare the two designs for analyzing the C1-2 complex on cervical spine lateral radiographs.

methodsA total of 1200 dynamic cervical spine X-ray and MRI pairs were collected from a tertiary care institution, and 300 studies from another institution were set aside for external validation. Two deep learning-based frameworks for localizing 8 landmarks and measuring 14 radiologic indices of the C1-2 complex were developed. The first of which is a multistage pipeline that implements coarse-to-fine localization, and the other is a single-stage model that processes full-region images. Five-fold cross-validation and an anatomy-aware multi-term loss were implemented, and performance was compared in terms of localization, segmentation, and measurement accuracy.

resultsThe multistage framework demonstrated significantly smaller errors for the localization of the basion and C2 landmarks on the test sets (p < 0.001). For vertebral segmentation, the multistage framework achieved better performance (p < 0.001), yielding DSC and IoU of over 0.90 and 0.80, respectively. Radiologic measurements were more precise with the multistage design, exhibiting mean errors of 1–2° for angular measurements and 0.5–1.5 mm for distance measurements.

conclusionsWe demonstrate that the multistage framework can consistently achieve superior performance over single-stage counterparts in analyzing cervical spine radiographs. It is expected to provide evidence for architectural design when developing deep learning models for the analysis of musculoskeletal imaging studies. CLINICAL TRIAL NUMBER: Not applicable.

Indexed as

Anatomic LandmarksCervical VertebraeDeep LearningHumansImage Processing, Computer-AssistedMagnetic Resonance ImagingRadiographyC1-2 complexCervical spine X-rayDeep learningImage segmentationLandmark localizationMultistage frameworkRadiologic measurement

Identifiers

PMID42032488
PMCPMC13273991

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.