Journal Article

DKFZ-2026-02361

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Anatomy- and Time-Based Post-Processing with CT Perfusion-Derived Time-Vessel Maps to Reduce Incorrect Occlusion Detections in Late-Phase CT Angiography.

Martinez Mora, A. (First author)DKFZ* ; Mojtahedi, M. ; de Vries, L. ; Baumgartner, M.DKFZ* ; Kirchhoff, Y.DKFZ* ; Zenk, M.DKFZ* ; Eckstein, K.DKFZ* ; Kächele, J.DKFZ* ; Brugnara, G.DKFZ* ; Bendszus, M. ; Radbruch, A. ; Roos, Y. ; van Zwam, W. ; van Oostenbrugge, R. ; Dippel, D. W. J. ; Emmer, B. J. ; Majoie, C. ; Vollmuth, P.DKFZ* ; Sánchez, C. I. ; Maier-Hein, K. H.DKFZ* ; Marquering, H. A.

2026
MDPI Basel

Abstract: Background/Objectives: Computer-aided vessel occlusion detection for acute ischemic stroke is typically developed on early-phase CT angiography (CTA). In late-phase CTA, enhanced venous contrast can mimic arterial occlusions and lead to incorrect occlusion detections. To counteract this, we propose a constraint-based post-processing framework that leverages anatomical and temporal vascular information from CT perfusion (CTP) scans. Methods: Vascular anatomy and relative contrast-arrival times were encoded as time-vessel maps. Three complementary constraints worked on these maps to remove incorrect detections based on distance-to-vessel truncation points, contrast-arrival time, and spatial priors. Constraints were fixed on a 32-case late-phase development subset and applied to an external held-out cohort of late-phase CTA (N = 354). To enable application without CTP, an auxiliary CTA-to-time-vessel map generator was designed to estimate maps directly from CTA. Results: In the external cohort, the framework reduced incorrect occlusions per scan from 3.9 (95% CI 3.6-4.2) to 2.1 (95% CI 1.9-2.3), preserving occlusion-level sensitivity at 80% (95% CI 69-91). The patient-level AUROC was 83 for the baseline versus 88 with post-processing. Improvements were also observed in detectors exposed to late-phase CTA, where post-processing reduced incorrect occlusions per scan from 2.8 to 1.9. As only 51 occlusion-positive cases were present in the external cohort, confidence intervals were wide. Consequently, these estimates should be interpreted with caution. Conclusions: Anatomically and temporally informed post-processing reduced incorrect occlusion detections in late-phase CTA without measurable loss of sensitivity, potentially improving robustness against CTA phase changes in external institutions.

Keyword(s): CT angiography ; CT perfusion ; acute ischemic stroke ; anatomical priors ; incorrect occlusion removal ; temporal priors ; vessel occlusion detection

Note: #EA:E230# / #DKTKZFB26# / #NCTZFB26#

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Contributing Institute(s):

1. Medizinische Bildverarbeitung (E230)
2. DKTK HD zentral (HD01)
3. Koordinierungsstelle NCT Heidelberg (HD02)

Research Program(s):

1. 315 - Bildgebung und Radioonkologie (POF4-315) (POF4-315)

Appears in the scientific report 2026

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Database coverage:
; ; ; Article Processing Charges ; Clarivate Analytics Master Journal List ; Current Contents - Clinical Medicine ; DOAJ Seal ; Ebsco Academic Search ; Essential Science Indicators ; Fees ; IF < 5 ; JCR ; PubMed Central ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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