Evidence map›Paper›PMID 41627717›Full record

ArticleRadiological physics and technology2026

Megavoltage computed tomography image quality assessment in a modern tomotherapy system: a frequency-domain analysis.

Hiroshi Kunitomo, Masato Yamada, Yuta Eguchi, Yuto Kitagawa, Kazuya Ohashi, Takahiro Tsuchiya, Hiroshi Fukuma, Katsuhiro Ichikawa

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Article in Radiological physics and technology, 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

What it found

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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

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

8 authors.

Hiroshi KunitomoMedical Equipment Engineering, School of Medical Sciences, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan. hiroshi.kunitomo@fujita-hu.ac.jp.ORCID http://orcid.org/0000-0002-2229-6565
Masato YamadaDepartment of Radiology, Nagoya City University Hospital, 1 Kawasumi, Mizuho, Mizuho, Nagoya, Aichi, 467-8602, Japan.
Yuta EguchiDepartment of Radiology, Nagoya City University Midori Municipal Hospital, 1-77 Shiomigaoka, Midori, Nagoya, Aichi, 458-0037, Japan.
Yuto KitagawaDepartment of Radiology, Nagoya City University Hospital, 1 Kawasumi, Mizuho, Mizuho, Nagoya, Aichi, 467-8602, Japan.
Kazuya OhashiDepartment of Radiology, Nagoya City University Midori Municipal Hospital, 1-77 Shiomigaoka, Midori, Nagoya, Aichi, 458-0037, Japan.
Takahiro TsuchiyaDepartment of Radiology, Nagoya City University Hospital, 1 Kawasumi, Mizuho, Mizuho, Nagoya, Aichi, 467-8602, Japan.
Hiroshi FukumaDepartment of Radiology, Nagoya City University Hospital, 1 Kawasumi, Mizuho, Mizuho, Nagoya, Aichi, 467-8602, Japan.
Katsuhiro IchikawaFaculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa, 920-0942, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

This study aimed to comprehensively evaluate the image quality of iterative (IR) and filtered back-projection (FBP) reconstruction in a modern megavoltage computed tomography (MV-CT) system using frequency-domain methods in both the in-plane and longitudinal directions. MV-CT scans of a Catphan 504 phantom were obtained using various pitch factors (PFs). The in-plane image quality was assessed using a task-based transfer function (TTF) and a noise power spectrum (NPS). The longitudinal characteristics were evaluated using the slice sensitivity profile (SSP) and modulation transfer function (MTF). Finally, the helical artifacts and radiation doses were quantified. The in-plane TTF and NPS for IR were independent of the PF. Compared to FBP, IR provided significant noise reduction (e.g., 73.3% lower NPS at 0.2 mm⁻1) but showed slightly lower TTF for moderate-contrast objects at low frequencies. In contrast, the longitudinal resolution was directly dependent on the PF; specifically, with increasing PF, the effective slice thickness widened from 3.7 mm (Fine) to 6.0 mm (Coarse), and the MTF degraded. This was accompanied by more pronounced helical artifacts as the circularity of the object decreased from 0.95 (PF 1.0) to 0.69 (PF 3.0). The IR provided remarkable noise reduction and improved soft-tissue visualization. However, the disparate behavior of resolution between imaging directions is a key finding: while the in-plane quality is consistent across pitch factors, the longitudinal resolution degrades significantly with a higher pitch. This characteristic has direct implications for the choice of imaging protocol, particularly for high-precision treatments where geometric accuracy is paramount.

Indexed as

Image Processing, Computer-AssistedTomography, X-Ray ComputedArtifactsPhantoms, ImagingQuality ControlRadiation DosageFrequency-Domain AnalysisImage-Guided Radiotherapy (IGRT)Image QualityIterative Reconstruction (IR)Megavoltage Computed Tomography (MV-CT)

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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.