Evidence map›Paper›PMID 42665934›Full record

ArticleJournal of applied clinical medical physics2026

Phantom evaluation of small-pixel effect in ultra-high-resolution photon-counting CT: Noise texture and high-contrast spatial resolution.

Kyu-Ho Song, Colin Shan, Gary Xu, Xinhui Duan, Yue Zhang, Kuan Zhang, Liqiang Ren

Abstract readEvaluation Study
In one paragraph

Article in Journal of applied clinical medical physics, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing 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

1 citing paper in PubMed.

  1. Article
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

7 authors.

Kyu-Ho SongDepartment of Radiology, UT Southwestern Medical Center, Dallas, Texas, USA.
Colin ShanDepartment of Radiology, UT Southwestern Medical Center, Dallas, Texas, USA.
Gary XuImaging Services, UT Southwestern Medical Center, Dallas, Texas, USA.
Xinhui DuanDepartment of Radiology, UT Southwestern Medical Center, Dallas, Texas, USA.
Yue ZhangDepartment of Radiology, UT Southwestern Medical Center, Dallas, Texas, USA.
Kuan ZhangDepartment of Radiology, UT Southwestern Medical Center, Dallas, Texas, USA.
Liqiang RenDepartment of Radiology, UT Southwestern Medical Center, Dallas, Texas, USA.

Funding

RSNA Research and Education Foundation RSCH2302
6 · The paper itself

Abstract

backgroundUltra-high-resolution (UHR) photon-counting CT (PCCT) with small-pixel detectors improves resolution and noise, but its dependence on diverse imaging conditions remains insufficiently characterized. PURPOSE: To systematically evaluate the small-pixel effect in UHR PCCT by assessing noise properties and high-contrast spatial resolution under varying acquisition and reconstruction conditions.

methodsImages of an ACR CT accreditation phantom with a body ring simulating a medium-sized patient were acquired on a clinical PCCT system (NAEOTOM Alpha.Peak, Siemens Healthineers, Germany) using standard-resolution (STD) and UHR modes. Scans were performed at dose levels ranging from 3 to 24 mGy. Reconstructions included slice thicknesses from 0.2/0.4 to 3.0 mm, convolution kernels from Br36 to Br72, quantum iterative reconstruction both off and at strength levels 1-4, matrix sizes of 512 to 1024, and field-of-view (FOV) settings from 210 to 350 mm. Both low-energy threshold (T3D) and virtual monoenergetic images were evaluated. Image noise was quantified using noise magnitude, noise power spectrum (NPS), and average spatial frequency. High-contrast spatial resolution was evaluated using the modulation transfer function and visual assessment of resolution patterns.

resultsCompared with the STD mode, the UHR mode consistently reduced image noise, with the greatest reductions observed at thinner slice thicknesses and with sharper kernels. In contrast, dose level, QIR strength, matrix size, and spectral image type had minimal influence on the relative noise differences between the two modes. NPS analysis further demonstrated lower noise magnitude and, depending on the imaging conditions, a shift of the noise spectrum toward lower spatial frequencies, indicating relative suppression of high-frequency noise in the UHR mode. High-contrast spatial resolution was more strongly influenced by imaging sampling conditions, particularly matrix size and FOV, and remained overall comparable between the STD and UHR modes.

conclusionsThe UHR mode of PCCT consistently achieves lower image noise than the STD mode without compromising high-contrast spatial resolution. Its greatest benefit is observed in high-spatial-resolution imaging protocols employing thin slice thicknesses and sharp reconstruction kernels, whereas the incremental benefit is limited for routine CT imaging. These findings support a task-based implementation of the UHR mode to optimize protocol selection according to clinical imaging requirements.

Indexed as

Image Processing, Computer-AssistedPhantoms, ImagingPhotonsTomography, X-Ray ComputedAlgorithmsHumansRadiotherapy Planning, Computer-AssistedSignal-To-Noise Ratiomodulation transfer functionnoise power spectrumphoton‐counting computed tomographysmall‐pixel effectultra‐high resolution

Identifiers

PMID42665934
PMCPMC13525204

What OpenQuestion holds

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Registered trials

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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.