Electron Density Phantom

Model 062M
Correlate CT Numner and Tissue Electron Density

Because CT scans are used to correct for tissue inhomogeneities in radiation therapy treatment planning, it’s important to obtain a precise relationship between CT number (in Hounsfield units) and electron densities. The Electron Density Phantom enables precise correlation of CT data to electron density of various tissues and is manufactured from CIRS tissue equivalent materials.

Tissue Equivalent Technology 

The phantom consists of two nested disks made from Plastic Water®-LR. The disks can represent both head and abdomen configurations. Nine different tissue equivalent electron density plugs can be positioned at 17 locations within the scan field. Included is a vial plug that can be filled with any fluid. Optional distance marker plugs enable quick assessment of the CT scanner’s distance measurement accuracy. 

Improved Accuracy 

Physicists performing treatment planning need accurate tools to evaluate CT scan data, correct for inhomogeneities and to document the relationship between CT number and tissue density. To improve the accuracy of your treatment planning, consider the Electron Density Phantom. 

  • Evaluate CT scan data
  • Correct for inhomogeneities
  • Document relationship between CT number and tissue electron density
  • Simulate indicated tissue within the diagnostic energy range
  • Quickly assess distance registration


Data Sheet

Electron Density Phantom: Data Sheet

Ronkainen, Ari-Petteri; Al-Gburi, Ali; Liimatainen, Timo; Matikka, Hanna; 'A dose–neutral image quality comparison of different CBCT and CT systems using paranasal sinus imaging protocols and phantoms'. European Archives of Oto-Rhino-Laryngology. 2022; 8-Jan. Springer. View
Hu, Yunfei; Arnesen, Marius; Aland, Trent; 'Characterization of an advanced cone beam CT (CBCT) reconstruction algorithm used for dose calculation on Varian Halcyon linear accelerators'. Biomedical Physics & Engineering Express. 2022; 8 (2): 25023. IOP Publishing. View
Gaddipati, Ravi; Jensen, Garrett L; Swanson, Gregory; Hammonds, Kendall; Morrow, Andrew; 'The Effect of High-Dose Radiation Therapy on Healthy Vertebral Bone Density'. Cureus. 2022; 14 (2): Cureus. View
Le Deroff, Coralie; Berger, Lucie; Bellec, Julien; Boissonnat, Guillaume; Chesneau, Héléna; Chiavassa, Sophie; Desrousseaux, Julie; Gempp, Stéphanie; Henry, Olivier; Jarril, Jimmy; 'Monte Carlo-based software for 3D personalized dose calculations in image-guided radiotherapy'. Physics and imaging in radiation oncology. 2022; 21: 108-114. Elsevier. View
Kolarevic, Goran; Jaroš, Dražan; Pavičar, Bojan; Ignjć, Tatjana; Kostovski, Aleksandar; Marosevic, Goran; Predojević, Branko; Mirjanić, Dragoljub; 'Computed tomography simulator conversion curve dependence on scan parameters and phantom dimension'. Journal of Health Sciences. 2021; View

Summary: The paper describes commissioning of a Varian Halcyon 1.0 linear accelerator, in which the Model 62M was used to calibrate CBCT image data to electron density units for the Eclipse Treatment Planning System while final end-to-end testing was performed using the Model 002LFC IMRT Thorax Phantom.
NIAMSAWAN, SASIPRAPA; Sookpeng, Supawitoo; 'The Impact of the variation of computed tomography simulation parameters to dose calculation in computer treatment planning for lung cancer patient'. 2021; Naresuan University. View
Al-Hayek, Yazan; Spuur, Kelly; Davidson, Rob; Hayre, Christopher; Zheng, Xiaoming; 'The Impact of Vertical Off-Centring, Tube Voltage and Phantom Size on CT Numbers: An Experimental Study'. Research Gate. 2021; View

Summary: Dedicated CT-to-ED phantom was scanned at 120 kV and 140 kV, to obtain CT-to-ED (ED- Electron Density) conversion curves as well as CTDIvol. Thoracal phantoms were scanned in standard and extended field of view to evaluate dosimetric effect on treatment planning and delivery.
Pettersson, E; Bäck, A; Thilander-Klang, A; 'Comparison of Metal Artefacts for Different Dual Energy CT Techniques'. Radiation Protection Dosimetry. 2021; View

Summary: In this comparison of two methods for obtaining dual-energy CT (DECT) images, performed with the 062M Electron Density Phantom, fast kV-switching was found to more accurately depict metal inserts than dual-source DECT.
Moteghaed, Niloofar Yousefi; Mostaar, Ahmad; Maghooli, Keivan; Houshyari, Mohammad; Ameri, Ahmad; 'Estimation and evaluation of pseudo-CT images using linear regression models and texture feature extraction from MRI images in the brain region to design external radiotherapy planning'. Radiation Oncology. 2021; 16 (1): 10-Jan. BioMed Central.

Summary: In this effort to develop Pseudo-CT planning images from MRIs of the head, the 62M electron density phantom was used to verify the accuracy of the HU-to-electron density measurement obtained from the reference CT scan.
Abascal, Juan FPJ; Ducros, Nicolas; Pronina, Valeriya; Rit, Simon; Rodesch, Pierre-Antoine; Broussaud, Thomas; Bussod, Suzanne; Douek, Philippe C; Hauptmann, Andreas; Arridge, Simon; 'Material Decomposition in Spectral CT using deep learning: A Sim2Real transfer approach'. IEEE Access. 2021; 9: 25632-25647. IEEE. View

Summary: Testing of a deep-learning algorithm designed to improve the speed and accuracy of spectral CT systems, performed in part on the CIRS Model 62M, is described.
Petrović, Borislava S; Faj, Dario Z; Marković, Mladen B; Tot, Arpad A; Marjanović, Milana S; Kasabašić, Mladen D; Gencel, Ivan V; Paunović, Dragomir R; Stanković, Jelena V; Krestić-Vesović, Jelena; 'Assessment of ct simulators used in radiotherapy treatment planning in Serbia, Croatia and Bosnia and Herzegovina'. On Line First. 2021; View
Brindhaban, A; Jassim, O; 'Effect of X-ray beam energy and image reconstruction technique on computed tomography numbers of various tissue equivalent materials'. Radiography. 2021; 27 (1): 95-100. epub. View
Hu, Yanle; Ding, Xiaoning; Shen, Jiajian; Bues, Martin; Liu, Wei; Kang, Yixiu; Leng, Shuai; Yu, Lifeng; 'Feasibility of using megavoltage computed tomography to reduce proton range uncertainty: A simulation study'. Journal of Applied Clinical Medical Physics. 2021; View
Zheng, Xiaoming; Al-Hayek, Yazan; Cummins, Chris; 'CORRECTION FOR CT NUMBER CHANGES CAUSED BY OFF-CENTRE PATIENT POSITIONING: A PHANTOM STUDY'. 19th Asian Oceanian Congress of Radiology. 2021; View
Jensen, Garrett L; Gaddipati, Ravi; Hammonds, Kendall P; Morrow, Andrew; Swanson, Gregory P; 'Bone Density Changes Following Radiotherapy to Vertebral Metastases'. Cureus. 2021; 13 (6): Cureus. View
Kassaee, Anthony; Cheng, Chingyun; Yin, Lingshu; Zou, Wei; Li, Taoran; Lin, Alexander; Swisher-McClure, Samuel; Lukens, John N; Lustig, Robert A; O'Reilly, Shannon; 'Dual-Energy Computed Tomography Proton-Dose Calculation with Scripting and Modified Hounsfield Units'. Int Jour Particle Therapy. 2021; 8 (1): View
Gong, Hao; Tao, Shengzhen; Gagneur, Justin D; Liu, Wei; Shen, Jiajian; McCollough, Cynthia H; Hu, Yanle; Leng, Shuai; 'Implementation and experimental evaluation of Mega-voltage fan-beam CT using a linear accelerator'. Radiation Oncology. 2021; View
Andersson, P; Pettersson, N; Lindberg, A; Swanpalmer, J; Chakarova, R; 'Effects of lung tissue characterization in radiotherapy of breast cancer under deep inspiration breath hold when using Monte Carlo dosimetry'. Physica Medica. 2021; View
Oria, Carmen Seller; Marmitt, Gabriel G; Free, Jeffrey; Langendijk, Johannes A; Both, Stefan; Knopf, Antje-Christin; Meijers, Arturs; 'Optimizing calibration settings for accurate water equivalent path length assessment using flat panel proton radiography'. Physics in Medicine & Biology. 2021; IOP Publishing. View
Puvanasunthararajah, Sathyathas; Fontanarosa, Davide; Wille, Marie‐Luise; Camps, Saskia M; 'The application of metal artifact reduction methods on computed tomography scans for radiotherapy applications: A literature review'. Journal of Applied Clinical Medical Physics. 2021; View
Buranaporn, Panyapat; Dankulchai, Pittaya; Jaikuna, Tanwiwat; Prasartseree, Tissana; 'Relation between DIR recalculated dose based CBCT and GI and GU toxicity in postoperative prostate cancer patients treated with VMAT'. Radiotherapy and Oncology. 2021; 157: 14-Aug. Elsevier. View
Zheng, Xiaoming; Gutsche, Lachlan; Al-Hayek, Yazan; Stanton, Johanna; Elshami, Wiam; Jensen, Kelsey; 'Impacts of Phantom Off-Center Positioning on CT Numbers and Dose Index CTDIv: An Evaluation of Two CT Scanners from GE'. Journal of Imaging. 2021; 7 (11): 235. Multidisciplinary Digital Publishing Institute. View

Summary: Electron-density values from the 62M were used to assess the affect of off-axis patient positioning during CT scanning of patients on dose delivery.
Yanju, YANG; Yang, ZHONG; Weigang, HU; Dadi, GAO; Jun, ZHAO; 'Effects of CT-RED calibration curves of different simulators on dose distribution of tumor target and organs at risk'. China Oncology. 2021; 31 (9): 828-837. View
Zimmermann, Lukas; Knäusl, Barbara; Stock, Markus; Lütgendorf-Caucig, Carola; Georg, Dietmar; Kuess, Peter; 'An MRI sequence independent convolutional neural network for synthetic head CT generation in proton therapy'. Zeitschrift für Medizinische Physik. 2021; Elsevier. View
Scholey, Jessica Elizabeth; 'Multimodal imaging and deep learning-based methods for improved dose calculation accuracy in photon and proton radiotherapy'. 2021; UCSF. View
Pelas, Chaz; 'Proton Radiography Using High Energy Pencil Beams from the Mevion S250i Proton Therapy System'. 2021; The University of Oklahoma Health Sciences Center. View
Yang, Bo; Yu, Lang; Wang, Zhiqun; Wang, Bei; Li, Wenbo; Zhang, Jie; Zhang, Xin; Wu, Zhufeng; Zhou, Zongkai; Sui, Hui; 'Experience on Commissioning the first Halcyon Linear Accelerator in China'. 2020; View
Hu, Yunfei; Byrne, Mikel; Archibald-Hareen, Ben; Collett, Nick; Liu, Guilin; Aland, Trent 'Validation of the preconfigured Varian Ethos Acuros XB Beam Model for treatment planning dose calculations: A dosimetric study.'. Journal of Applied Clinical Medical Physics. 2020; View
Kim, Bitbyeol; Junga, Seongmoon; Sona, Jaeman; Choi, Chang Heon; Kim, Jung-in; Park, Jong Min; 'Estimation of Effective Atomic Number using Dual-Energy Imaging of CT Simulator for Radiation Therapy'. Transaction of the Korean Nuclear Society Virtual Autumn Meeting. 2020; View

Summary: Measurements of electron density were used to estimate effective atomic numbers with a CT simulator. Implementation of appropriate noise reduction techniques is recommended before this technique can replace DECT measurements.
Yoonc, Euntaek; Junga, Seongmoon; Sona, Jaeman; Kimc, Bitbyeol; Choia, Chang Heon; Parka, Jong Min; 'Dose calculation on dual energy CT images for carbon ion therapy using TOPAS: a Monte Carlo Study'. Transaction of the Korean Nuclear Society Virtual Autumn Meeting. 2020; View

Summary: Single-energy CT reference data from the 62M was used to create an effective atomic number (Zeff) of each tissue imaged under dual-energy CT. Zeff was was then used model dose delivery during carbon ion radiotherapy using the TOPAS Model Carlo simulation.
Brevitt, Barrington A; Suarez, Edwin Ges; Clemente, Rafael A Miller; Voutchkov, Mitko; 'Evaluating the Impact of CT Scanning Parameters on Dose Calculations by the Treatment Planning System in External Beam Radiation Therapy'. Journal of Cancer Therapy and Research. 2020; 1 (1): epub. View
Nakao, Minoru; Ozawa, Shuichi; Miura, Hideharu; Yamada, Kiyoshi; Habara, Kosaku; Hayata, Masahiro; Kusaba, Hayate; Kawahara, Daisuke; Miki, Kentaro; Nakashima, Takeo; 'Development of a CT number calibration audit phantom in photon radiation therapy: A pilot study'. Medical physics. 2020; 47 (4): 1509-1522. Wiley Online Library. View
Sudhyadhom, Atchar; 'On the molecular relationship between Hounsfield Unit (HU), mass density, and electron density in computed tomography (CT)'. PLOS One. 2020; epub. View
Jung, Seongmoon; Kim, Bitbyeol; Kim, Jung-in; Park, Jong Min; Choi, Chang Heon; 'Deriving the Effective Atomic Number with a Dual-Energy Image Set Acquired by the Big Bore CT Simulator'. Journal of Radiation Protection and Research. 2020; 45 (4): 171-177. Korean Association for Radiation Protection. View
Zheng, Xiaoming; Al-Hayek, Yazan; Cummins, Chris; Li, Xiaotian; Nardi, Laura; Albari, Khaled; Evans, James; Roworth, Evan; Seaton, Ty; 'Body size and tube voltage dependent corrections for Hounsfield Unit in medical X-ray computed tomography: theory and experiments'. Scientific reports. 2020; View
Alaka, BG; Bentefour, El H; Chirvase, Cezarina; Samuel, Deepak; Teo, Boon-Keng Kevin; 'Feasibility of energy-resolved dose imaging technique in pencil beam scanning mode'. Biomedical Physics & Engineering Express. 2020; 6 (6): 65009. IOP Publishing. View
Hickman, Dillon; Zhang, Jie; McQuerry, Kristen; Lee, James; 'Should radiologists care about kV? Phantom and clinical study of effects of kV on hemoperitoneum HU in the setting of splenic injuries'. Emergency radiology. 2020; 27 (2): 135-140. Springer. View
Schröder, Lukas; Stankovic, Uros; Sonke, Jan‐Jakob; 'Long‐term stability of Hounsfield unit calibration for cone beam computed tomography'. Medical physics. 2020; 47 (4): 1640-1644. Wiley Online Library. View
Tanaka, Sodai; Noto, Yoshiyuki; Utsunomiya, Satoru; Yoshimura, Takaaki; Matsuura, Taeko; Saito, Masatoshi; 'Proton dose calculation based on converting dual-energy CT data to stopping power ratio (DEEDZ-SPR): a beam-hardening assessment'. Physics in Medicine & Biology. 2020; 65 (23): 235046. IOP Publishing. View
Mohamed Bahaaeldin Afifi, A. Abdelrazek, Nashaat Ahmed Deiab, A.I. Abd El-Hafez, A.H. El-Farrash 'The effects of CT x-ray tube voltage and current variations on the relative electron density (RED) and CT number conversion curves'. Journal of Radiation Research and Applied Sciences. 2020; 13 (1): 11-Jan. View
Cavalcanti, Lucas de Brito; Santos, Maíra Ribeiro dos; 'Validation of the tomography calibration curve for the Radiotherapy planning system at the National Cancer Institute'. Proceedings of the 24. Brazilian congress on medical physics. 2019; View
Gayou, Oliver 'Influence of acquisition parameters on MV-CBCT image quality'. Journal of Applied Clinical Medical Physics. 2012; View
Salas Ramirez, Maikol; 'Methods to Improve Bone Marrow Dosimetry in Molecular Radiotherapy'. Julius-Maximilians-Universität Würzburg. View


Model: 062M Modalities: ,