[Intl_DxMedPhys] [External] Re: CT artifact

Thu Jul 16 10:28:35 EDT 2026

It is a little sus that the cerebellum is enhancing so much within the well defined borders of the tentorium cerebelli (that hyper dense strip between the cerebelum and the rest of the brain). I think the hyperdense region in the middle of the cerebellum on the images you showed is partly a result of some beam hardening near the t bone anatomy like previously discussed, but no cone angle or BH artifact is going to enhance the entire cereblumm like that. If the complaint is just about the slightly higher hyperdensities here (see the image below from a routine head from my place, I put a cross hair on an axial and SA, you can see the hyper density part if away from the borders of the hounsfield's bar region), this may be some BH from the temporal bone anatomy.

So this dark/bright appearance can be thought of as the darkness from hounsdield bar between the t bone, and the brightness from traditional bone bleed through into brain, causing that cereblum to have the appearance it does. But this is pretty common on most heads. I would have the rad review a few cases with you, or compare some CT priors for another patient who got the same protocol on the same scanner but has scans from another CT scanner in your fleet as a prior.

As an aside, I would check how your site is making the reformats, they look like they are being made form too thick of source recons. On a canon scanner that you have, you can set the source volume to have thin, like 0.5 or 1 right? Then make reformats from that thicker? The reformats you show look like they are thick made from this. Compare to my SA below, the correlations in noise are uniform image top-bottom left-right, wheraes your are longer top-bottom which tells me the source slice was possibly too large?

[cid:aa796f02-2b43-4549-a376-6712a465b2fb]

Timothy P. Szczykutowicz, Ph.D., DABR
Professor
Departments of Radiology, Medical Physics and BME
University of Wisconsin Madison
Cell# 1-716-560-7751<tel:(716)%20560-7751>
Office# 1-608-263-5729
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From: Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list-bounces at lists.osu.edu> on behalf of Tang, Xiangyang via Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list at lists.osu.edu>
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To: Stephanie M. Leon <Stephanie.M.Leon at hitchcock.org>; intl_dxmedphys_wd_osu_list at lists.osu.edu <intl_dxmedphys_wd_osu_list at lists.osu.edu>; Li, Baojun <baojunli at bu.edu>
Subject: Re: [Intl_DxMedPhys] [External] Re: CT artifact

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Hi Stephanie, In addition to Baojun's comments, another possibility for the root cause for the artifacts can be the data inconsistency that is induced by the cone angle during data acquisition, which may exist in either helical or axial scan. 
Hi Stephanie,

In addition to Baojun's comments, another possibility for the root cause for the artifacts can be the data inconsistency that is induced by the cone angle during data acquisition, which may exist in either helical or axial scan.

Best regards,

Xiangyang

Xiangyang Tang, PhD, DABR, FSPIE, FAAPM & FAIMBE
Professor of Radiology and Imaging Sciences
PI, Translational Research in CT Lab
Director, Medical Physics Imaging Residency Program
Department of Radiology and Imaging Sciences
Emory University School of Medicine

The book entitled "Spectral Multi-Detector CT (sMDCT): Data Acquisition, Image Formation, Quality Assessment and Contrast Enhancement<https://urldefense.com/v3/__https://www.amazon.com/Spectral-Multi-Detector-Computed-Tomography-sMDCT/dp/0367137534?source=ps-sl-shoppingads-lpcontext&ref_=fplfs&psc=1&smid=ATVPDKIKX0DER__;!!KGKeukY!0OUypJHAAFg21kS7W3auLfH133sr72DMejboDtUYaxJXzaMB0DG8MxB799_4PdMGaaVlHi4SKKTXpW5M0nBDjacrHLFStAE_Z8b1uT7BM84iY1Jeyg$>"

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email: xiangyang.tang at emory.edu

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From: Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list-bounces+xiangyang.tang=emory.edu at lists.osu.edu> on behalf of Li, Baojun via Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list at lists.osu.edu>
Sent: Wednesday, July 15, 2026 2:40 PM
To: Stephanie M. Leon <Stephanie.M.Leon at hitchcock.org>; intl_dxmedphys_wd_osu_list at lists.osu.edu <intl_dxmedphys_wd_osu_list at lists.osu.edu>
Subject: [External] Re: [Intl_DxMedPhys] CT artifact

Hi Stephanie, The cerebellum is near the temporal bone and the skull base, so it tends to be affected by beam hardening. The BH effect makes the pixels brighter. I also observed some radial banding patterns, which may be the result of helical

Hi Stephanie,

The cerebellum is near the temporal bone and the skull base, so it tends to be affected by beam hardening. The BH effect makes the pixels brighter. I also observed some radial banding patterns, which may be the result of helical interpolation or sagittal reformatting.

Baojun

From: Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list-bounces at lists.osu.edu> On Behalf Of Stephanie M. Leon via Intl_dxmedphys_wd_osu_list
Sent: Wednesday, July 15, 2026 12:21 PM
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Subject: [Intl_DxMedPhys] CT artifact

Hi all, I have an odd CT artifact that a radiologist brought to my attention. The top image has bright gyri on the right cerebrum. The 2nd image shows the gyri okay in the left cerebrum, but very bright in the cerebellum. The cerebellum is also

Hi all,

I have an odd CT artifact that a radiologist brought to my attention. The top image has bright gyri on the right cerebrum.  The 2nd image shows the gyri okay in the left cerebrum, but very bright in the cerebellum.  The cerebellum is also very bright in the 3rd image.

This is from a Canon Aquilion Prime SP, helical acquisition, AIDR 3D recon and FC26 kernel. It is apparent in the axial images too, just a bit harder to see. The patient received an MRI to follow up, which was normal.

Any ideas??

[cid:image002.png at 01DD1454.4BD806C0]

[cid:image006.png at 01DD1467.CBEBFB10]

[cid:image007.png at 01DD1467.CBEBFB10]

Stephanie M. Leon, PhD, DABR, DABSNM

Chief of Diagnostic Medical Physics

Associate Professor of Radiology

Tel (603) 650-3796
Dartmouth-Health.org

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