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Zhu Q, Wei S, Wang Z, Xu H, Zhou B, Qu H, Nie M, Guo N, Wang W, Yang B, Qiu J. Feasibility of dose calculation for treatment plans using electron density maps from a novel dual-layer detector spectral CT simulator. Radiat Oncol 2024; 19:93. [PMID: 39049106 PMCID: PMC11267670 DOI: 10.1186/s13014-024-02479-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Accepted: 06/21/2024] [Indexed: 07/27/2024] Open
Abstract
BACKGROUND Conventional single-energy CT can only provide a raw estimation of electron density (ED) for dose calculation by developing a calibration curve that simply maps the HU values to ED values through their correlations. Spectral CT, also known as dual-energy CT (DECT) or multi-energy CT, can generate a series of quantitative maps, such as ED maps. Using spectral CT for radiotherapy simulations can directly acquire ED information without developing specific calibration curves. The purpose of this study is to assess the feasibility of utilizing electron density (ED) maps generated by a novel dual-layer detector spectral CT simulator for dose calculation in radiotherapy treatment plans. METHODS 30 patients from head&neck, chest, and pelvic treatment sites were selected retrospectively, and all of them underwent spectral CT simulation. Treatment plans based on conventional CT images were transplanted to ED maps with the same structure set, including planning target volume (PTV) and organs at risk (OARs), and the dose distributions were then recalculated. The differences in dose and volume histogram (DVH) parameters of the PTV and OARs between the two types of plans were analyzed and compared. Besides, gamma analysis between these plans was performed by using MEPHYSTO Navigator software. RESULTS In terms of PTV, the homogeneity index (HI), gradient index (GI), D2%, D98%, and Dmean showed no significant difference between conventional plans and ED plans. For OARs, statistically significant differences were observed in parotids D50%, brainstem in head&neck plans, spinal cord in chest plans and rectum D50% in pelvic plans, whereas the variance remained minor. For the rest, the DVH parameters exhibited no significant difference between conventional plans and ED plans. All of the mean gamma passing rates (GPRs) of gamma analysis were higher than 90%. CONCLUSION Compared to conventional treatment plans relying on CT images, plans utilizing ED maps demonstrated similar dosimetric quality. However, the latter approach enables direct utilization in dose calculation without the requirements of establishing and selecting a specific Hounsfield unit (HU) to ED calibration curve, providing an advantage in clinical applications.
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Affiliation(s)
- Qizhen Zhu
- Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Shuoyang Wei
- Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Zhiqun Wang
- Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Haoran Xu
- Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Bing Zhou
- Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Huiying Qu
- Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | | | - Ning Guo
- Philips Clinical Science, Beijing, China
| | | | - Bo Yang
- Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
| | - Jie Qiu
- Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
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Rodriguez-Granillo GA, Cirio J, Vila JF, Langzam E, Ivanc T, Fontana L, Descalzo A, Rubilar B, Lylyk P. Noncontrast Myocardial Characterization in Acute Myocardial Infarction Using Electron Density Imaging. J Thorac Imaging 2024; 39:173-177. [PMID: 37884390 DOI: 10.1097/rti.0000000000000749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
PURPOSE Spectral computed tomography (CT) enables improved tissue characterization, although virtually all research has focused on contrast-enhanced examinations. We hypothesized that changes in myocardial tissue related to acute myocardial infarction (AMI) might potentially be identified without the need for contrast administration using electron density (ED) imaging. PATIENTS AND METHODS This retrospective observational study involved a small series (n = 15) of patients admitted to our institution with a first AMI without signs of hemodynamic instability and identification of a culprit vessel with invasive coronary angiography during the same admission, who also underwent a noncontrast, low-dose chest CT using a dual-layer spectral CT scanner. Images were assessed in search of dark areas with low density on ED imaging, and the mean percentage ED relative to water (%EDW) was calculated. RESULTS Using a qualitative approach, ED assessment enabled the identification of 11/15 (73%) affected coronary territories, with a sensitivity of 73% (95% CI: 45; 92%) and a specificity of 87% (95% CI: 69; 96%). AMI segments showed significantly lower ED values than the remote myocardium (103.8 ± 0.8 vs 104.3 ± 0.6 %EDW, P < 0.0001), and a threshold below 103.9 %EDW had a sensitivity of 66% and specificity of 79% for the identification of AMI. In a control group of patients without a history of cardiovascular disease, none had areas with focal reduction of ED following the shape of the myocardial wall. CONCLUSIONS In our preliminary series, ED imaging showed the potential to enable the identification of myocardial tissue changes related to AMI without iodinated contrast requirement.
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Affiliation(s)
| | | | | | - Eran Langzam
- Philips Healthcare, CT Clinical Science, Buenos Aires, Argentina
| | - Thomas Ivanc
- Philips Healthcare, CT Clinical Science, Buenos Aires, Argentina
| | | | | | | | - Pedro Lylyk
- Department of Interventional Neuroradiology, Instituto Medico ENERI, Clinica La Sagrada Familia
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Chen M, Jiang Y, Zhou X, Wu D, Xie Q. Dual-Energy Computed Tomography in Detecting and Predicting Lymph Node Metastasis in Malignant Tumor Patients: A Comprehensive Review. Diagnostics (Basel) 2024; 14:377. [PMID: 38396416 PMCID: PMC10888055 DOI: 10.3390/diagnostics14040377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 02/05/2024] [Accepted: 02/06/2024] [Indexed: 02/25/2024] Open
Abstract
The accurate and timely assessment of lymph node involvement is paramount in the management of patients with malignant tumors, owing to its direct correlation with cancer staging, therapeutic strategy formulation, and prognostication. Dual-energy computed tomography (DECT), as a burgeoning imaging modality, has shown promising results in the diagnosis and prediction of preoperative metastatic lymph nodes in recent years. This article aims to explore the application of DECT in identifying metastatic lymph nodes (LNs) across various cancer types, including but not limited to thyroid carcinoma (focusing on papillary thyroid carcinoma), lung cancer, and colorectal cancer. Through this narrative review, we aim to elucidate the clinical relevance and utility of DECT in the detection and predictive assessment of lymph node metastasis in malignant tumors, thereby contributing to the broader academic discourse in oncologic radiology and diagnostic precision.
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Affiliation(s)
| | | | | | - Di Wu
- Department of Radiology, The Eighth Affiliated Hospital, Sun Yat-sen University, Shenzhen 518036, China; (M.C.); (Y.J.); (X.Z.)
| | - Qiuxia Xie
- Department of Radiology, The Eighth Affiliated Hospital, Sun Yat-sen University, Shenzhen 518036, China; (M.C.); (Y.J.); (X.Z.)
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Zhu L, Du Y, Peng Y, Xiang X, Wang X. Investigation on the proton range uncertainty with spectral CT-based virtual monoenergetic images. J Appl Clin Med Phys 2023; 24:e14062. [PMID: 37312288 PMCID: PMC10562040 DOI: 10.1002/acm2.14062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 05/22/2023] [Accepted: 05/23/2023] [Indexed: 06/15/2023] Open
Abstract
OBJECTIVE The stopping power ratio (SPR) prediction error will contribute to the range uncertainty of proton therapy. Spectral CT is promising in reducing the uncertainty in SPR estimation. The purpose of this research is to determine the optimal energy pairs of SPR prediction for each tissue and to evaluate the dose distribution and range difference between the spectral CT with the optimal energy pairs method and the single energy CT (SECT) method. METHODS A new method was proposed based on image segmentation to calculate the proton dose with spectral CT images for the head and body phantom. CT number of each organ region were converted to SPR with the optimal energy pairs of each organ. The CT images were segmented into different organ parts with thresholding method. Virtual monoenergetic (VM) images from 70 keV to 140 keV were investigated to determine the optimal energy pairs for each organ based on Gammex 1467 phantom. The beam data of Shanghai Advanced Proton Therapy facility (SAPT) was employed in matRad (an open-source software for radiation treatment planning) for the dose calculation. RESULTS The optimal energy pairs were obtained for each tissue. The dose distribution of two tumor sites (brain and lung) were calculated with the aforementioned optimal energy pairs. The maximum dose deviation between spectral CT and SECT at the target region was 2.57% and 0.84% for the lung tumor and brain tumor respectively. The range difference between spectral and SECT was significant with 1.8411 mm for the lung tumor. γ passing rate was 85.95% and 95.49% for the lung tumor and brain tumor with the criterion 2%/2 mm. CONCLUSIONS This work presents a way to determine the optimal energy pairs for each organ and to calculate the dose distribution based on the more accurate SPR prediction.
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Affiliation(s)
- Libing Zhu
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, PR China
| | - Yi Du
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiotherapy, Peking University Cancer Hospital & Institute, Beijing, PR China
| | - Yahui Peng
- School of Electronic and Information Engineering, Beijing Jiaotong University, Beijing, PR China
| | - Xincheng Xiang
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, PR China
| | - Xiangang Wang
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, PR China
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Peña JA, Shaul JL, Müller M, Damm T, Barkmann R, Kurz B, Campbell GM, Freitag-Wolf S, Glüer CC. Dual-Layer Spectral-Computed Tomography Enhances the Separability of Calcium-Based Implant Material from Bone: An Ex Vivo Quantitative Imaging Study. J Bone Miner Res 2022; 37:2472-2482. [PMID: 36125939 DOI: 10.1002/jbmr.4710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 08/22/2022] [Accepted: 09/17/2022] [Indexed: 11/10/2022]
Abstract
Local treatment of bone loss with an injection of a resorbable, calcium-based implant material to replace bone has a long history of clinical use. The in vivo discrimination of changes in bone versus implant is challenging with standard computed tomography (CT). However, spectral-CT techniques enable the separation between tissues of similar densities but different chemical compositions. Dual-layer spectral-CT imaging and postprocessing analysis methods were applied to investigate the separability of AGN1 (a triphasic calcium-based implant) and bone after AGN1 injection in n = 10 male cadaveric femurs ex vivo. Using the area under the curve (AUC) from receiver-operating characteristic (ROC) analyses, the separability of AGN1 from bone was assessed for AGN1 (postoperatively) versus compact and versus femoral neck cancellous bone (both preoperatively). CT techniques included conventional Hounsfield (HU) and density-equivalent units (BMD, mg hydroxyapatite [HA]/cm3 ) and spectral-CT measures of effective atomic number (Zeff) and electron density (ED). The samples had a wide range of femoral neck BMD (55.66 to 241.71 mg HA/cm3 ). At the injection site average BMD, HU, Zeff, and ED increased from 69.5 mg HA/cm3 , 109 HU, 104.38 EDW, and 8.30 Zeff in the preoperative to 1233 mg HA/cm3 , 1741 HU, 181.27 EDW, and 13.55 Zeff in the postoperative CT scan, respectively. For compact bone at the femoral shaft the preoperative values were 1124.15 mg HA/cm3 , 1648 HU, 177 EDW, and 13.06 Zeff and were maintained postoperatively. Zeff showed substantially sharper distributions and significantly greater separability compared to ED, BMD, and HU (all p < 0.002, for both regions) with average AUCs for BMD, HU, ED, and Zeff of 0.670, 0.640, 0.645, and 0.753 for AGN1 versus compact and 0.996, 0.995, 0.994, and 0.998 for AGN1 versus femoral neck cancellous sites, respectively. Spectral-CT permits better discrimination of calcium-based implants like AGN1 from bone ex vivo. Our results warrant application of spectral-CT in patients undergoing procedures with similar implants. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Jaime A Peña
- Section Biomedical Imaging, Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein (UKSH), Kiel, Germany
| | | | - Michael Müller
- Clinic for Orthopedics and Trauma Surgery, University Medical Center Schleswig-Holstein (UKSH), Kiel, Germany
| | - Timo Damm
- Section Biomedical Imaging, Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein (UKSH), Kiel, Germany
| | - Reinhard Barkmann
- Section Biomedical Imaging, Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein (UKSH), Kiel, Germany
| | - Bodo Kurz
- Department of Anatomy, Christian-Albrechts University (CAU), Kiel, Germany
| | | | - Sandra Freitag-Wolf
- Institute of Medical Informatics and Statistics, Christian-Albrechts University (CAU), Kiel, Germany
| | - Claus-C Glüer
- Section Biomedical Imaging, Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein (UKSH), Kiel, Germany
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Koch V, Albrecht MH, Gruenewald LD, Yel I, Eichler K, Gruber-Rouh T, Hammerstingl RM, Burck I, Wichmann JL, Alizadeh LS, Vogl TJ, Lenga L, Wesarg S, Martin SS, Mader C, Dimitrova M, D'Angelo T, Booz C. Impact of Intravenously Injected Contrast Agent on Bone Mineral Density Measurement in Dual-Source Dual-Energy CT. Acad Radiol 2022; 29:880-887. [PMID: 34266738 DOI: 10.1016/j.acra.2021.06.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/07/2021] [Accepted: 06/11/2021] [Indexed: 12/01/2022]
Abstract
PURPOSE To assess the influence of intravenously injected contrast agent on bone mineral density (BMD) assessment in dual-source dual-energy CT. METHODS This retrospective study included 1,031 patients (mean age, 53 ± 7 years; 519 women) who had undergone third-generation dual-source dual-energy CT in context of tumor staging between January 2019 and December 2019. Dedicated postprocessing software based on material decomposition was used for phantomless volumetric BMD assessment of trabecular bone of the lumbar spine. Volumetric trabecular BMD values derived from unenhanced and contrast-enhanced portal venous phase were compared by calculating correlation and agreement analyses using Pearson product-moment correlation, linear regression, and Bland-Altman plots. RESULTS Mean BMD values were 115.53 ± 37.23 and 116.10 ± 37.78 mg/cm3 in unenhanced and contrast-enhanced dual-energy CT series, respectively. Values from contrast-enhanced portal venous phase differed not significantly from those of the unenhanced phase (p = 0.44) and showed high correlation (r = 0.971 [95% CI, 0.969-0.973]) with excellent agreement in Bland-Altman plots. Mean difference of the two phases was 0.61 mg/cm3 (95% limits of agreement, -17.14 and 18.36 mg/cm3). CONCLUSION Portal venous phase dual-source dual-energy CT allows for accurate opportunistic BMD assessment of trabecular bone of the lumbar spine compared to unenhanced imaging. Therefore, dual-source CT may provide greater flexibility regarding BMD assessment in clinical routine and reduce radiation exposure by avoiding additional osteodensitometry examinations, as contrast-enhanced CT scans in context of tumor staging are increasingly performed in dual-energy mode.
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Affiliation(s)
- Vitali Koch
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Moritz H Albrecht
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Leon D Gruenewald
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Ibrahim Yel
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Katrin Eichler
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Tatjana Gruber-Rouh
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Renate M Hammerstingl
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Iris Burck
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Julian L Wichmann
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Leona S Alizadeh
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Thomas J Vogl
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany; Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Lukas Lenga
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Stefan Wesarg
- Fraunhofer IGD, Cognitive Computing & Medical Imaging, Darmstadt, Germany
| | - Simon S Martin
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Christoph Mader
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Mirela Dimitrova
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Tommaso D'Angelo
- Department of Biomedical Sciences and Morphological and Functional Imaging, University Hospital Messina, Messina, Italy
| | - Christian Booz
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany.
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Dual-energy CT of acute bowel ischemia. Abdom Radiol (NY) 2022; 47:1660-1683. [PMID: 34191075 DOI: 10.1007/s00261-021-03188-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 12/17/2022]
Abstract
Acute bowel ischemia is a condition with high mortality and requires rapid intervention to avoid catastrophic outcomes. Swift and accurate imaging diagnosis is essential because clinical findings are commonly nonspecific. Conventional contrast enhanced CT of the abdomen has been the imaging modality of choice to evaluate suspected acute bowel ischemia. However, subtlety of image findings and lack of non-contrast or arterial phase images can make correct diagnosis challenging. Dual-energy CT provides valuable information toward assessing bowel ischemia. Dual-energy CT exploits the differential X-ray attenuation at two different photon energy levels to characterize the composition of tissues and reveal the presence or absence of faint intravenous iodinated contrast to improve reader confidence in detecting subtle bowel wall enhancement. With the same underlying technique, virtual non-contrast images can help to show non-enhancing hyperdense hemorrhage of the bowel wall in intravenous contrast-enhanced scans without the need to acquire actual non-contrast scans. Dual-energy CT derived low photon energy (keV) virtual monoenergetic images emphasize iodine contrast and provide CT angiography-like images from portal venous phase scans to better evaluate abdominal arterial patency. In Summary, dual-energy CT aids diagnosing acute bowel ischemia in multiple ways, including improving visualization of the bowel wall and mesenteric vasculature, revealing intramural hemorrhage in contrast enhanced scans, or possibly reducing intravenous contrast dose.
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Sato K, Sato C, Takahashi A, Takano H, Kayano S, Ishiguro A, Takane Y, Kaneta T. Accuracy of virtual monochromatic images generated by the decomposition of photoelectric absorption and Compton scatter in dual-energy computed tomography. Phys Eng Sci Med 2022; 45:239-249. [PMID: 35089524 DOI: 10.1007/s13246-022-01107-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 01/19/2022] [Indexed: 11/27/2022]
Abstract
The decomposition of the linear attenuation coefficient into photoelectric absorption and Compton scattering provides virtual monochromatic images (VMIs). The accuracy of the computed tomography (CT) number of VMI, which is obtained by decomposing the linear attenuation coefficient into photoelectric absorption and Compton scattering, was verified in the energy range of 40-200 keV. The possibility of improving the accuracy of CT numbers by using pre-energy-calibrated images as input was also investigated. The VMIs were generated in two groups of images: (i) dual-energy scanned images and (ii) high- and low-energy images generated by two-material decomposition (i.e., pre-energy-calibrated images). The object for analysis was solid iodine rods inserted in the center of the multi-energy CT phantom. The VMIs were generated from the dual-energy scanned images and pre-energy-calibrated images, and the theoretical and measured CT numbers of solid iodine rods were compared. Furthermore, the absolute error (AE) and relative error (RE) were calculated. With both images, the accuracy of the CT numbers was extremely high for regions close to the high- and low-tube-voltage X-ray energy or the high and low energy of the input images. By using the pre-energy-calibrated images, the maximum AE was reduced from 133 to 96 HU at an energy of 40 keV. Similarly, the maximum RE was reduced from 325 to 50% at an energy of 200 keV. The pre-energy-calibrated images reduced the overall error of the CT numbers and controlled the energy region where accurate CT numbers could be obtained.
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Affiliation(s)
- Kazuhiro Sato
- Health Sciences, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
| | - Chifumi Sato
- Tohoku University School of Health Sciences, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Ayami Takahashi
- Tohoku University School of Health Sciences, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Hirokazu Takano
- Department of Radiology, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8574, Japan
| | - Shingo Kayano
- Department of Radiology, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8574, Japan
| | - Ayana Ishiguro
- Department of Radiology, Sendai Open Hospital, 5‑22‑1 Tsurugaya, Miyagino‑ku, Sendai, Miyagi, 983‑0824, Japan
| | - Yumi Takane
- Department of Radiology, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8574, Japan
| | - Tomohiro Kaneta
- Health Sciences, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
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Shim E, Kim BH, Kang WY, Hong SJ, Kang CH, Ahn KS, Lee H, Kwack TJ. Diagnostic performance of electron-density dual-energy CT in detection of cervical disc herniation in comparison with standard gray-scale CT and virtual non-calcium images. Eur Radiol 2022; 32:2209-2220. [PMID: 35064315 PMCID: PMC8782689 DOI: 10.1007/s00330-021-08374-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 09/14/2021] [Accepted: 09/30/2021] [Indexed: 01/07/2023]
Abstract
Objectives To assess the diagnostic performance of dual-energy CT (DECT) with electron-density (ED) image reconstruction compared with standard CT (SC) and virtual non-calcium (VNCa) image CT reconstruction for detecting cervical disc herniation. Methods This cross-sectional study was approved by the IRB. We enrolled 64 patients (336 intervertebral discs from C2/3 to C7/T1; mean age, 55 years; 17 women and 47 men) who underwent DECT with spectral reconstruction and 3-T MRI within 2 weeks between January 2018 and June 2020. Four radiologists independently evaluated the first image set of randomized SC, VNCa, and ED images to detect cervical disc herniation. After 8 weeks, the readers re-evaluated the second and the last image sets with an 8-week interval. MRI evaluations performed by two other experienced served as the reference standard. Comparing diagnostic performance between each images set was evaluated by a generalized estimating equation. Results A total of 233 cervical disc herniations were noted on MRI. For detecting cervical disc herniation, electron-density images showed higher sensitivity (94% [219/233; 95% CI, 90–97] vs. 76% [177/233; 70–81] vs. 69% [160/233; 62–76]) (p < 0.001) and similar specificity (90% [93/103; 83–95] vs. 89% [92/103; 82–96] vs. 90% [93/103; 83–95]) (p > 0.05) as SC and VNCa images, respectively. Inter-reader agreement for cervical disc herniation calculated among the four readers was moderate for all image sets (κ = 0.558 for ED, κ = 0.422 for SC, and κ = 0.449 for VNCa). Conclusion DECT with ED reconstruction can improve cervical disc herniation detection and diagnostic confidence compared with SC and VNCa images. Key Points • Intervertebral discs with high material density are well visualized on electron-density images obtained from dual-energy CT. • Electron-density images showed much higher sensitivity and diagnostic accuracy than standard CT and virtual non-calcium images for the detection of cervical disc herniation. • Electron-density images can have false-negative results, especially for disc herniation with high signal intensity on T2W images and can show pseudo-disc extrusion at the lower cervical spine. Supplementary Information The online version contains supplementary material available at 10.1007/s00330-021-08374-y.
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Longarino FK, Tessonnier T, Mein S, Harrabi SB, Debus J, Stiller W, Mairani A. Dual-layer spectral CT for proton, helium, and carbon ion beam therapy planning of brain tumors. J Appl Clin Med Phys 2022; 23:e13465. [PMID: 34724327 PMCID: PMC8803296 DOI: 10.1002/acm2.13465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 08/23/2021] [Accepted: 10/14/2021] [Indexed: 01/21/2023] Open
Abstract
Pretreatment computed tomography (CT) imaging is an essential component of the particle therapy treatment planning chain. Treatment planning and optimization with charged particles require accurate and precise estimations of ion beam range in tissues, characterized by the stopping power ratio (SPR). Reduction of range uncertainties arising from conventional CT-number-to-SPR conversion based on single-energy CT (SECT) imaging is of importance for improving clinical practice. Here, the application of a novel imaging and computational methodology using dual-layer spectral CT (DLCT) was performed toward refining patient-specific SPR estimates. A workflow for DLCT-based treatment planning was devised to evaluate SPR prediction for proton, helium, and carbon ion beam therapy planning in the brain. DLCT- and SECT-based SPR predictions were compared in homogeneous and heterogeneous anatomical regions. This study included eight patients scanned for diagnostic purposes with a DLCT scanner. For each patient, four different treatment plans were created, simulating tumors in different parts of the brain. For homogeneous anatomical regions, mean SPR differences of about 1% between the DLCT- and SECT-based approaches were found. In plans of heterogeneous anatomies, relative (absolute) proton range shifts of 0.6% (0.4 mm) in the mean and up to 4.4% (2.1 mm) at the distal fall-off were observed. In the investigated cohort, 12% of the evaluated organs-at-risk (OARs) presented differences in mean or maximum dose of more than 0.5 Gy (RBE) and up to 6.8 Gy (RBE) over the entire treatment. Range shifts and dose differences in OARs between DLCT and SECT in helium and carbon ion treatment plans were similar to protons. In the majority of investigated cases (75th percentile), SECT- and DLCT-based range estimations were within 0.6 mm. Nonetheless, the magnitude of patient-specific range deviations between SECT and DLCT was clinically relevant in heterogeneous anatomical sites, suggesting further study in larger, more diverse cohorts. Results indicate that patients with brain tumors may benefit from DLCT-based treatment planning.
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Affiliation(s)
- Friderike K. Longarino
- German Cancer Research Center (DKFZ)Clinical Cooperation Unit Radiation OncologyHeidelbergGermany
- Department of Radiation OncologyHeidelberg University HospitalHeidelbergGermany
- Department of Physics and AstronomyHeidelberg UniversityHeidelbergGermany
| | | | - Stewart Mein
- Department of Radiation OncologyHeidelberg University HospitalHeidelbergGermany
- Heidelberg Ion Beam Therapy Center (HIT)HeidelbergGermany
- German Cancer Research Center (DKFZ)Translational Radiation OncologyHeidelbergGermany
- National Center for Radiation Research in Oncology (NCRO)Heidelberg Institute of Radiation Oncology (HIRO)HeidelbergGermany
- National Center for Tumor Diseases (NCT)HeidelbergGermany
| | - Semi B. Harrabi
- Department of Radiation OncologyHeidelberg University HospitalHeidelbergGermany
- Heidelberg Ion Beam Therapy Center (HIT)HeidelbergGermany
- National Center for Radiation Research in Oncology (NCRO)Heidelberg Institute of Radiation Oncology (HIRO)HeidelbergGermany
- National Center for Tumor Diseases (NCT)HeidelbergGermany
| | - Jürgen Debus
- German Cancer Research Center (DKFZ)Clinical Cooperation Unit Radiation OncologyHeidelbergGermany
- Department of Radiation OncologyHeidelberg University HospitalHeidelbergGermany
- Heidelberg Ion Beam Therapy Center (HIT)HeidelbergGermany
- National Center for Radiation Research in Oncology (NCRO)Heidelberg Institute of Radiation Oncology (HIRO)HeidelbergGermany
- National Center for Tumor Diseases (NCT)HeidelbergGermany
- Partner Site HeidelbergGerman Cancer Consortium (DKTK)HeidelbergGermany
| | - Wolfram Stiller
- Diagnostic and Interventional Radiology (DIR)Heidelberg University HospitalHeidelbergGermany
| | - Andrea Mairani
- Department of Radiation OncologyHeidelberg University HospitalHeidelbergGermany
- Heidelberg Ion Beam Therapy Center (HIT)HeidelbergGermany
- National Center for Tumor Diseases (NCT)HeidelbergGermany
- Medical PhysicsNational Centre of Oncological Hadrontherapy (CNAO)PaviaItaly
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11
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Bae K, Jeon KN. Diagnosis of Pulmonary Embolism in Unenhanced Dual Energy CT Using an Electron Density Image. Diagnostics (Basel) 2021; 11:diagnostics11101841. [PMID: 34679538 PMCID: PMC8534653 DOI: 10.3390/diagnostics11101841] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 10/01/2021] [Accepted: 10/04/2021] [Indexed: 11/19/2022] Open
Abstract
Dual-energy computed tomography (CT) is a promising tool, providing both anatomical information and material properties. Using spectral information such as iodine mapping and virtual monoenergetic reconstruction, dual-energy CT showed added value over pulmonary CT angiography in the diagnosis of pulmonary embolism. However, the role of non-contrast-enhanced dual energy CT in pulmonary embolism has never been reported. Here, we report a case of acute pulmonary embolism detected on an electron density image from an unenhanced dual-energy CT using a dual-layer detector system.
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Affiliation(s)
- Kyungsoo Bae
- Department of Radiology, Institute of Health Sciences, School of Medicine, Gyeongsang National University, Jinju 52727, Korea;
- Department of Radiology, Gyeongsang National University Changwon Hospital, Changwon 51472, Korea
| | - Kyung-Nyeo Jeon
- Department of Radiology, Institute of Health Sciences, School of Medicine, Gyeongsang National University, Jinju 52727, Korea;
- Department of Radiology, Gyeongsang National University Changwon Hospital, Changwon 51472, Korea
- Correspondence: ; Tel.: +82-55-214-3896
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12
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Yingying L, Zhe Z, Xiaochen W, Xiaomei L, Nan J, Shengjun S. Dual-layer detector spectral CT-a new supplementary method for preoperative evaluation of glioma. Eur J Radiol 2021; 138:109649. [PMID: 33730659 DOI: 10.1016/j.ejrad.2021.109649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 02/27/2021] [Accepted: 03/09/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE To investigate the value of the iodine concentration (IC) measured by dual-layer detector spectral CT (DLDSCT) in evaluating the factors related to the treatment scheme and survival prognosis of patients with glioma. METHODS From 2018 to 2019, we prospectively collected the data of 99 patients with glioma. The degree of CT enhancement and the IC of low grade gliomas (LGGs, II), high grade gliomas (HGGs, III and IV), grade II and III gliomas, were compared. The predictive performance of the degree of CT enhancement and IC was examined via receiver operating characteristic (ROC) analysis. The correlations between IC and Ki-67 labeling index, isocitrate dehydrogenase (IDH) mutation, chromosome 1p/19q deletion status of the tumor were examined. RESULTS Both IC and the degree of CT enhancement of patients with HGG were significantly higher than those of patients with LGG (p < 0.001; χ2 =41.707, p < 0.001); IC had large area under the ROC curve for diagnostic HGG (0.931; 95 % CI: 0.882-0.979; p < 0.001). The IC in the grade III gliomas was significantly higher than that in grade II gliomas (p < 0.001); IC had a large area under the ROC curve for diagnostic grade III gliomas (0.865; 95 % CI: 0.779-0.952; p < 0.001). There was a significant positive correlation between IC and Ki-67 LI (r = 0.679; p < 0.001). CONCLUSIONS The DLDSCT technology can be used as a supplementary method to provide more information for preoperative grading of the gliomas and the prognosis assessment of the patients.
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Affiliation(s)
- Li Yingying
- Department of Radiology, Beijing Chaoyang Hospital, Capital Medical University, No. 8 Gongti South Road, Beijing, 100024, China
| | - Zhang Zhe
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China; China National Clinical Research Center for Neurological Diseases, Beijing, China
| | - Wang Xiaochen
- Department of Radiology, Beijing Tiantan Hospital, Capital Medical University, No.119 Fanyang Road, Fengtai District, Beijing, 100070, China
| | - Lu Xiaomei
- CT Clinical Science, Philips Healthcare, Shenyang, 110016, China
| | - Ji Nan
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China; China National Clinical Research Center for Neurological Diseases, Beijing, China; Advanced Innovation Center for Big Data-Based Precision Medicine, China.
| | - Sun Shengjun
- Department of Neuroradiology, Beijing Neurosurgical Institute, No.119 Fanyang Road, Fengtai District, Beijing, 100070, China.
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13
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Rehani MM, Heil J, Baliyan V. Multicentric study of patients receiving 50 or 100 mSv in a single day through CT imaging-frequency determination and imaging protocols involved. Eur Radiol 2021; 31:6612-6620. [PMID: 33683390 DOI: 10.1007/s00330-021-07734-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 12/17/2020] [Accepted: 02/01/2021] [Indexed: 02/06/2023]
Abstract
OBJECTIVES To assess the magnitude and characterization of CT imaging protocols of patients receiving 50 or 100 mSv in a single day. METHODS In this multicentric retrospective study covering up to 279 hospitals from January 2015 to December 2019, the effective dose (E) as estimated by dose management system from dose length product of patients was filtered and grouped into per-day dose bands (≤ 20, > 20-50, > 50-70, > 70-100, > 100-200, > 200 mSv). Information on patient's age and imaging protocol was noted. The data were analyzed to determine the frequency of occurrence in each dose band. Top 20 CT imaging protocols that led to patients with a dose of ≥ 50 mSv in a single acquisition were identified and their relative frequency was estimated. RESULTS A total of approx. 4.3 million (4,283,738) CT exams were performed in approx. 3.9 million (3,880,524) patient-days indicating 9.41% had more than one CT exam in a single day. There were 31,058 (0.8%) patient-days with ≥ 50 mSv and 1191 (0.03%) with ≥ 100 mSv. Nearly 1/3rd patient-days reaching ≥ 50 mSv were of patients aged 50 years or younger. The top 20 CT imaging protocols that led to ≥ 50 mSv in a single day belonged to the body region (chest or abdomen and pelvis) and nearly one-third were angiographic studies. CONCLUSIONS In the first study of its kind, we report that patients with 50 mSv+ in a single day or a single exam are not rare. The information on imaging protocols leading to such doses and their frequency has been provided to help develop dose management strategies. KEY POINTS • Our study of 4,283,738 CT exams performed in 3,880,524 patient-days indicates 0.8% with 50 mSv+ and 0.03% with 100 mSv+ in a single day. • A total of 9.41% underwent more than one CT exam in a single day; nearly 1/3rd of those with 50 mSv+ were ≤ 50 years of age. • Identified top 20 CT imaging protocols that led to 50 mSv+ doses in a single exam. All belong to chest or abdomen and pelvis and nearly 1/3rd were angiographic studies.
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Affiliation(s)
- Madan M Rehani
- Massachusetts General Hospital, 55 Fruit Str, Boston, MA, 02114, USA. .,Radiology Department, Massachusetts General Hospital, 175 Cambridge Str., Suite 244, Boston, MA, 02114, USA.
| | - John Heil
- Imalogix Research Institute, Bryn Mawr, PA, 19010, USA
| | - Vinit Baliyan
- Massachusetts General Hospital, 55 Fruit Str, Boston, MA, 02114, USA
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14
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Noid G, Schott D, Paulson E, Zhu J, Shah J, Li XA. Technical Note: Using virtual noncontrast images from dual-energy CT to eliminate the need of precontrast CT for x-ray radiation treatment planning of abdominal tumors †. Med Phys 2021; 48:1365-1371. [PMID: 33386614 DOI: 10.1002/mp.14702] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 10/27/2020] [Accepted: 12/09/2020] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Radiation therapy (RT) planning frequently utilizes contrast-enhanced CT. However, dose calculations should not be performed on a contrast-enhanced CT because the patient will not receive bolus during treatment. It is typical to acquire CT twice during RT simulation: once before injection of bolus and once after. The registration between these datasets introduces errors. In this work, we investigate the use of virtual noncontrast images (VNC) derived from dual-energy CT (DECT) to eliminate the precontrast CT and the registration error. METHODS CT datasets, including conventional 120 kVp pre- and postcontrast CTs and postcontrast DECT, acquired for ten pancreatic cancer patients were evaluated. The DECTs were acquired simultaneously using a dual source (DS) CT simulator. VNC and virtual mono-energetic images (VMI) were derived from DECTs. Gross tumor volumes (GTV), planning target volumes (PTV), and organs at risks (OAR) were delineated on the postcontrast CT and then populated to the precontrast CT and the VNC. An IMRT plan (50.4 Gy in 28 fractions) was then optimized on the precontrast CT. Dose distributions were recalculated on the VNC images. Contours from the pre- and postcontrast CTs and the dose distributions based on both were compared. RESULTS On average, the distance of centroids of the populated duodenum contours on precontrast CT differed by 6.0 ± 4.0 mm from those on postcontrast CTs. The dose distributions on the precontrast CT and VNC were almost identical. The PTV mean and maximum doses differed by 0.1% and 0.2% between the two plans, respectively. CONCLUSION The VNC derived from DECT can be used to replace the conventional precontrast CT scan for RT planning, eliminating the need for an additional precontrast CT scan and eliminating the registration errors. Thus, VNC can become an important asset to the future of RT.
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Affiliation(s)
- George Noid
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Diane Schott
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Eric Paulson
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Justin Zhu
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Jainil Shah
- Siemens Medical Solutions USA, Inc., Malvern, PA, USA
| | - X Allen Li
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, USA
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15
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Quantitative accuracy of virtual non-contrast images derived from spectral detector computed tomography: an abdominal phantom study. Sci Rep 2020; 10:21575. [PMID: 33299004 PMCID: PMC7725817 DOI: 10.1038/s41598-020-78518-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 11/17/2020] [Indexed: 11/25/2022] Open
Abstract
Dual-energy CT allows for the reconstruction of virtual non-contrast (VNC) images. VNC images have the potential to replace true non-contrast scans in various clinical applications. This study investigated the quantitative accuracy of VNC attenuation images considering different parameters for acquisition and reconstruction. An abdomen phantom with 7 different tissue types (different combinations of 3 base materials and 5 iodine concentrations) was scanned using a spectral detector CT (SDCT). Different phantom sizes (S, M, L), volume computed tomography dose indices (CTDIvol 10, 15, 20 mGy), kernel settings (soft, standard, sharp), and denoising levels (low, medium, high) were tested. Conventional and VNC images were reconstructed and analyzed based on regions of interest (ROI). Mean and standard deviation were recorded and differences in attenuation between corresponding base materials and VNC was calculated (VNCerror). Statistic analysis included ANOVA, Wilcoxon test and multivariate regression analysis. Overall, the VNCerror was − 1.4 ± 6.1 HU. While radiation dose, kernel setting, and denoising level did not influence VNCerror significantly, phantom size, iodine content and base material had a significant effect (e.g. S vs. M: − 1.2 ± 4.9 HU vs. − 2.1 ± 6.0 HU; 0.0 mg/ml vs. 5.0 mg/ml: − 4.0 ± 3.5 HU vs. 5.1 ± 5.0 HU and 35-HU-base vs. 54-HU-base: − 3.5 ± 4.4 HU vs. 0.7 ± 6.5; all p ≤ 0.05). The overall accuracy of VNC images from SDCT is high and independent from dose, kernel, and denoising settings; however, shows a dependency on patient size, base material, and iodine content; particularly the latter results in small, yet, noticeable differences in VNC attenuation.
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Pawałowski B, Panek R, Szweda H, Piotrowski T. Combination of dual-energy computed tomography and iterative metal artefact reduction to increase general quality of imaging for radiotherapy patients with high dense materials. Phantom study. Phys Med 2020; 77:92-99. [PMID: 32818774 DOI: 10.1016/j.ejmp.2020.08.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 07/23/2020] [Accepted: 08/07/2020] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To evaluate the use of pseudo-monoenergetic reconstructions (PMR) from dual-energy computed tomography, combined with the iterative metal artefact reduction (iMAR) method. METHODS Pseudo-monoenergetic CT images were obtained using the dual-energy mode on the Siemens Somatom Definition AS scanner. A range of PMR combinations (70-130 keV) were used with and without iMAR. A Virtual Water™ phantom was used for quantitative assessment of error in the presence of high density materials: titanium, alloys 330 and 600. The absolute values of CT number differences (AD) and normalised standard deviations (NSD) were calculated for different phantom positions. Image quality was assessed using an anthropomorphic pelvic phantom with an embedded hip prosthesis. Image quality was scored blindly by five observers. RESULTS AD and NSD values revealed differences in CT number errors between tested sets. AD and NSD were reduced in the vicinity of metal for images with iMAR (p < 0.001 for AD/NSD). For ROIs away from metal, with and without iMAR, 70 keV PMR and pCT AD values were lower than for the other reconstructions (p = 0.039). Similarly, iMAR NSD values measured away from metal were lower for 130 keV and 70 keV PMR (p = 0.002). Image quality scores were higher for 70 keV and 130 keV PMR with iMAR (p = 0.034). CONCLUSION The use of 70 keV PMR with iMAR allows for significant metal artefact reduction and low CT number errors observed in the vicinity of dense materials. It is therefore an attractive alternative to high keV imaging when imaging patients with metallic implants, especially in the context of radiotherapy planning.
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Affiliation(s)
- Bartosz Pawałowski
- Department of Medical Physics, Greater Poland Cancer Centre, Poznań, Poland; Department of Technical Physics, Poznan University of Technology, Poznań, Poland
| | - Rafał Panek
- Medical Physics & Clinical Engineering, Nottingham University Hospitals NHS Trust, Nottingham, UK; School of Medicine, University of Nottingham, Nottingham, UK
| | - Hubert Szweda
- Department of Medical Physics, Greater Poland Cancer Centre, Poznań, Poland
| | - Tomasz Piotrowski
- Department of Medical Physics, Greater Poland Cancer Centre, Poznań, Poland; Department of Electroradiology, Poznań University of Medical Sciences, Poznań, Poland.
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17
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Noid G, Zhu J, Tai A, Mistry N, Schott D, Prah D, Paulson E, Schultz C, Li XA. Improving Structure Delineation for Radiation Therapy Planning Using Dual-Energy CT. Front Oncol 2020; 10:1694. [PMID: 32984048 PMCID: PMC7484725 DOI: 10.3389/fonc.2020.01694] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 07/29/2020] [Indexed: 12/11/2022] Open
Affiliation(s)
- George Noid
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Justin Zhu
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - An Tai
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Nilesh Mistry
- Siemens Medical Solutions USA, Inc., Malvern, PA, United States
| | - Diane Schott
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Douglas Prah
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Eric Paulson
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Christopher Schultz
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - X. Allen Li
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States
- *Correspondence: X. Allen Li,
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18
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Faller FK, Mein S, Ackermann B, Debus J, Stiller W, Mairani A. Pre-clinical evaluation of dual-layer spectral computed tomography-based stopping power prediction for particle therapy planning at the Heidelberg Ion Beam Therapy Center. ACTA ACUST UNITED AC 2020; 65:095007. [DOI: 10.1088/1361-6560/ab735e] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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19
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Pawałowski B, Szweda H, Dudkowiak A, Piotrowski T. Quality evaluation of monoenergetic images generated by dual-energy computed tomography for radiotherapy: A phantom study. Phys Med 2019; 63:48-55. [PMID: 31221408 DOI: 10.1016/j.ejmp.2019.05.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 04/08/2019] [Accepted: 05/25/2019] [Indexed: 12/15/2022] Open
Abstract
PURPOSE Quantification analysis for monoenergetic computed tomography (CT) images obtained from dual-energy CT scanning was performed in the light of their potential use for structures delineation during radiotherapy. METHODS Parameters that describe the quality of the images are: linearity, low and high contrast resolution, uniformity, noise and signal to noise ratio (SNR). To evaluate these parameters, a Catphan phantom was scanned using a dual-energy mode at Somatom Definition AS. Based on the polyenergetic CT images, sixteen monoenergetic series (ranged from 40 keV to 190 keV) were created by CT scanner software and automatically analyzed using Artiscan software. RESULTS Analysis of linearity shows that a potential use of any monoenergetic images in radiotherapy planning requires that individual calibration curves are implemented for each of them. While the results of the high contrast resolution analysis were comparable for each energy (5 lp/cm), the results of the analyses for uniformity, low contrast resolution, noise and SNR allowed us to select the best imaging energies. The highest relative uniformity was detected for images reconstructed for energies of 60 keV and 70 keV (98.54% and 98.61%). Similar results were observed for low contrast resolution, where the largest number of disks was detected for these energies, and the noise values (0.42% for 60 keV, 0.44% for 70 keV). The best SNR was observed for images reconstructed for energy of 60 keV. CONCLUSIONS Taking into account these results, the energy of 70 keV was selected as potentially the best for reconstruction of monoenergetic images used for structures delineation during radiotherapy.
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Affiliation(s)
- Bartosz Pawałowski
- Department of Medical Physics, Greater Poland Cancer Centre, Poznań, Poland; Department of Technical Physics, Poznan University of Technology, Poznan, Poland
| | - Hubert Szweda
- Department of Medical Physics, Greater Poland Cancer Centre, Poznań, Poland
| | - Alina Dudkowiak
- Department of Technical Physics, Poznan University of Technology, Poznan, Poland
| | - Tomasz Piotrowski
- Department of Medical Physics, Greater Poland Cancer Centre, Poznań, Poland; Department of Electroradiology, Poznań University of Medical Sciences, Poznań, Poland.
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20
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Landry G, Dörringer F, Si‐Mohamed S, Douek P, Abascal JFPJ, Peyrin F, Almeida IP, Verhaegen F, Rinaldi I, Parodi K, Rit S. Technical Note: Relative proton stopping power estimation from virtual monoenergetic images reconstructed from dual‐layer computed tomography. Med Phys 2019; 46:1821-1828. [DOI: 10.1002/mp.13404] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 01/14/2019] [Accepted: 01/18/2019] [Indexed: 01/24/2023] Open
Affiliation(s)
- Guillaume Landry
- Department of Medical Physics Faculty of Physics Ludwig‐Maximilians‐Universität München Munich Germany
| | - Fabian Dörringer
- Department of Medical Physics Faculty of Physics Ludwig‐Maximilians‐Universität München Munich Germany
| | - Salim Si‐Mohamed
- Radiology Department Centre Hospitalier Universitaire Lyon France
- Univ Lyon INSA‐Lyon Université Claude Bernard Lyon 1 UJM‐Saint‐Étienne CNRS Inserm CREATIS UMR 5220 U1206 F‐69373 Lyon France
| | - Philippe Douek
- Radiology Department Centre Hospitalier Universitaire Lyon France
- Univ Lyon INSA‐Lyon Université Claude Bernard Lyon 1 UJM‐Saint‐Étienne CNRS Inserm CREATIS UMR 5220 U1206 F‐69373 Lyon France
| | - Juan F. P. J. Abascal
- Univ Lyon INSA‐Lyon Université Claude Bernard Lyon 1 UJM‐Saint‐Étienne CNRS Inserm CREATIS UMR 5220 U1206 F‐69373 Lyon France
| | - Françoise Peyrin
- Univ Lyon INSA‐Lyon Université Claude Bernard Lyon 1 UJM‐Saint‐Étienne CNRS Inserm CREATIS UMR 5220 U1206 F‐69373 Lyon France
- ESRF The European Synchrotron Grenoble France
| | - Isabel P. Almeida
- Department of Radiation Oncology (MAASTRO) GROW School for Oncology and Developmental Biology Maastricht University Medical Centre Maastricht The Netherlands
| | - Frank Verhaegen
- Department of Radiation Oncology (MAASTRO) GROW School for Oncology and Developmental Biology Maastricht University Medical Centre Maastricht The Netherlands
| | - Ilaria Rinaldi
- Department of Radiation Therapy and Oncology Heidelberg University Hospital Im Neuenheimer Feld 400 69120 Heidelberg Germany
- CNRS/IN2P3 and Lyon 1 University UMR 5822 Villeurbanne France
- MAASTRO Clinic Dr. Tanslaan 12 6229 ET Maastricht The Netherlands
| | - Katia Parodi
- Department of Medical Physics Faculty of Physics Ludwig‐Maximilians‐Universität München Munich Germany
| | - Simon Rit
- Univ Lyon INSA‐Lyon Université Claude Bernard Lyon 1 UJM‐Saint‐Étienne CNRS Inserm CREATIS UMR 5220 U1206 F‐69373 Lyon France
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