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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. </div>
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Hi Stephanie,</div>
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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.</div>
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Xiangyang</div>
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Xiangyang Tang, PhD, DABR, FSPIE, FAAPM & FAIMBE</div>
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Emory University School of Medicine</div>
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The book entitled "<a href="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$" title="https://www.amazon.com/Spectral-Multi-Detector-Computed-Tomography-sMDCT/dp/0367137534?source=ps-sl-shoppingads-lpcontext&ref_=fplfs&psc=1&smid=ATVPDKIKX0DER"><b>Spectral
Multi-Detector CT (sMDCT): Data Acquisition, Image Formation, Quality Assessment and Contrast Enhancement</b></a><b>"</b></div>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list-bounces+xiangyang.tang=emory.edu@lists.osu.edu> on behalf of Li, Baojun via Intl_dxmedphys_wd_osu_list
<intl_dxmedphys_wd_osu_list@lists.osu.edu><br>
<b>Sent:</b> Wednesday, July 15, 2026 2:40 PM<br>
<b>To:</b> Stephanie M. Leon <Stephanie.M.Leon@hitchcock.org>; intl_dxmedphys_wd_osu_list@lists.osu.edu <intl_dxmedphys_wd_osu_list@lists.osu.edu><br>
<b>Subject:</b> [External] Re: [Intl_DxMedPhys] CT artifact</font>
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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</div>
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<p class="x_MsoNormal"><span style="font-size:11.0pt; font-family:"Calibri",sans-serif; color:#1F497D">Hi Stephanie,</span></p>
<p class="x_MsoNormal"><span style="font-size:11.0pt; font-family:"Calibri",sans-serif; color:#1F497D"> </span></p>
<p class="x_MsoNormal"><span style="font-size:11.0pt; font-family:"Calibri",sans-serif; color:#1F497D">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.</span></p>
<p class="x_MsoNormal"><span style="font-size:11.0pt; font-family:"Calibri",sans-serif; color:#1F497D"> </span></p>
<p class="x_MsoNormal"><span style="font-size:11.0pt; font-family:"Calibri",sans-serif; color:#1F497D">Baojun</span></p>
<p class="x_MsoNormal"><span style="font-size:11.0pt; font-family:"Calibri",sans-serif; color:#1F497D"> </span></p>
<p class="x_MsoNormal"><span style="font-size:11.0pt; font-family:"Calibri",sans-serif; color:#1F497D"> </span></p>
<p class="x_MsoNormal"><b><span style="font-size:11.0pt; font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt; font-family:"Calibri",sans-serif"> Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list-bounces@lists.osu.edu>
<b>On Behalf Of </b>Stephanie M. Leon via Intl_dxmedphys_wd_osu_list<br>
<b>Sent:</b> Wednesday, July 15, 2026 12:21 PM<br>
<b>To:</b> intl_dxmedphys_wd_osu_list@lists.osu.edu<br>
<b>Subject:</b> [Intl_DxMedPhys] CT artifact</span></p>
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<p class="x_MsoNormal" style=""><span style="font-size:1.0pt; color:white">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</span></p>
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<p class="x_MsoNormal">Hi all,</p>
<p class="x_MsoNormal"> </p>
<p class="x_MsoNormal">I have an odd CT artifact that a radiologist brought to my attention. The top image has bright gyri on the right cerebrum. The 2<sup>nd</sup> image shows the gyri okay in the left cerebrum, but very bright in the cerebellum. The cerebellum
is also very bright in the 3<sup>rd</sup> image. </p>
<p class="x_MsoNormal"> </p>
<p class="x_MsoNormal">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.</p>
<p class="x_MsoNormal"> </p>
<p class="x_MsoNormal">Any ideas??</p>
<p class="x_MsoNormal"> </p>
<p class="x_MsoNormal"> </p>
<p class="x_MsoNormal"><span style=""><img width="463" height="416" id="x_Picture_x0020_5" alt="cid:image002.png@01DD1454.4BD806C0" style="width:4.8263in; height:4.3333in" data-outlook-trace="F:1|T:1" src="cid:image001.png@01DD1467.DB7D9390"></span></p>
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<p class="x_MsoNormal"> </p>
<p class="x_MsoNormal"><b><span style="font-family:"Arial",sans-serif; color:#639044">Stephanie M. Leon, PhD, DABR, DABSNM</span></b><span style="font-family:"Arial",sans-serif; color:#78BE20"></span></p>
<p class="x_MsoNormal"><span style="font-family:"Arial",sans-serif; color:#00664F">Chief of Diagnostic Medical Physics</span></p>
<p class="x_MsoNormal" style="margin-bottom:12.0pt"><span style="font-family:"Arial",sans-serif; color:#00664F">Associate Professor of Radiology</span></p>
<p class="x_MsoNormal"><span style="font-family:"Arial",sans-serif; color:#00664F">Tel (603) 650-3796<br>
Dartmouth-Health.org</span></p>
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