Evidence map›Paper›PMID 42684484›Full record

ArticleEuropean radiology2026

Identifying optimal dose head CT acquisition techniques through cluster analysis from 904,209 scans.

Berk Yildirim, Denise Bos, Taewoon Kang, Carly Stewart, Timothy P Szczykutowicz, Rebecca Smith-Bindman

Abstract read
PubMed Publisher
In one paragraph

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

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Berk YildirimClinic for Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany. Berk.Yildirim@med.uni-heidelberg.de.ORCID http://orcid.org/0009-0009-8533-6016
Denise BosInstitute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
Taewoon KangDepartment of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, USA.
Carly StewartDepartment of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, USA.
Timothy P SzczykutowiczDepartment of Radiology, University of Wisconsin, Madison, WI, USA.
Rebecca Smith-BindmanDepartment of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, USA.

Funding

NCI NIH HHS 1R01CA181191-01A1Patient-Centered Outcomes Research Institute CD-1304-7043 and DI-2018C1-11375
6 · The paper itself

Abstract

objectivesTo identify clinically established and frequently utilized routine head computed tomography (CT) acquisition techniques in children and adults that achieve lower radiation. MATERIALS AND

methodsThe level of the analysis is at the CT scan (series) level. CT acquisition parameters were analyzed from a large, international CT dose registry. Scans were analyzed separately in adults and children, and by approach (helical or axial), resulting in four strata. K-means clustering, an unsupervised machine learning approach, assigned the scans into clusters based on the following acquisition parameters: Tube current, voltage, collimation, scan length, and for helical scans, pitch. Effective patient diameter, unadjusted and patient size-adjusted dose-length product (DLP), and volume CT dose index (CTDI

results864,182 CT scans in adults and 40,027 scans in children between January 1, 2015, and March 11, 2021, were included in the analysis. Scans were classified into seven helical and six axial clusters in adults, six helical and four axial clusters in children. In all four strata, the mean size-adjusted DLP varied more than two-fold, and up to 3.4-fold, across the clusters. For example, for adult helical scans (the largest strata), the size-adjusted DLP ranged from 372 mGy·cm to 998 mGy·cm (relative dose 2.7) across clusters. Clusters with the lowest radiation generally utilized lower tube current and voltage, but protocols utilized various approaches to result in lower doses.

conclusionThere remains a large variation in the radiation dose within frequently used head CT acquisition techniques. Clustering analysis enables identifying protocols with lower doses. KEY POINTS: Question Is there a large variation in the doses used for routine head CT, and can we identify best-practice, lowest dose approaches for scanning? Findings Across each stratum (adult/pediatric, helical/axial), the mean size-adjusted DLP varied by more than two-fold across the CT scan clusters, reflecting significant differences in radiation. Clinical relevance Many routine head CT acquisition techniques use excessive radiation doses. Standardizing practice to the lowest dose clusters would result in significant reductions in patient dose.

Indexed as

HeadHealth physicsPatient safetyRadiation protectionTomography, X-ray computed

Identifiers

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

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.