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Tunissen SAM, Smit EJ, Mikerov M, Prokop M, Sechopoulos I. Performance evaluation of a 4D similarity filter for dynamic CT angiography imaging of the liver. Med Phys 2024. [PMID: 39264288 DOI: 10.1002/mp.17394] [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: 05/09/2024] [Revised: 08/20/2024] [Accepted: 08/23/2024] [Indexed: 09/13/2024] Open
Abstract
BACKGROUND Dynamic computed tomography (CT) angiography of the abdomen provides perfusion information and characteristics of the tissues present in the abdomen. This information could potentially help characterize liver metastases. However, radiation dose has to be relatively low for the patient, causing the images to have very high noise content. Denoising methods are needed to increase image quality. PURPOSE The purpose of this study was to investigate the performance, limitations, and behavior of a new 4D filtering method, called the 4D Similarity Filter (4DSF), to reduce image noise in temporal CT data. METHODS The 4DSF averages voxels with similar time-intensity curves (TICs). Each phase is filtered individually using the information of all phases except for the one being filtered. This approach minimizes the bias toward the noise initially present in this phase. Since the 4DSF does not base similarity on spatial proximity, loss of spatial resolution is avoided. The 4DSF was evaluated on a 12-phase liver dynamic CT angiography acquisition of 52 digital anthropomorphic phantoms, each containing one hypervascular 1 cm lesion with a small necrotic core. The metrics used for evaluation were noise reduction, lesion contrast-to-noise ratio (CNR), CT number accuracy using peak-time and peak-intensity of the TICs, and resolution loss. The results were compared to those obtained by the time-intensity profile similarity (TIPS) filter, which uses the whole TIC for determining similarity, and the combination 4DSF followed by TIPS filter (4DSF + TIPS). RESULTS The 4DSF alone resulted in a median noise reduction by a factor of 6.8, which is lower than that obtained by the TIPS filter at 8.1, and 4DSF + TIPS at 12.2. The 4DSF increased the median CNR from 0. 44 to 1.85, which is less than the TIPS filter at 2.59 and 4DSF + TIPS at 3.12. However, the peak-intensity accuracy in the TICs was superior for the 4DSF, with a median intensity decrease of -34 HU compared to -88 and -50 HU for the hepatic artery when using the TIPS filter and 4DSF + TIPS, respectively. The median peak-time accuracy was inferior for the 4DSF filter and 4DSF + TIPS, with a time shift of -1 phases for the portal vein TIC compared to no shift in time when using the TIPS. The analysis of the full-width-at-half-maximum (FWHM) of a small artery showed significantly less spatial resolution loss for the 4DSF at 3.2 pixels, compared to the TIPS filter at 4.3 pixels, and 3.4 pixels for the 4DSF + TIPS. CONCLUSION The 4DSF can reduce noise with almost no resolution loss, making the filter very suitable for denoising 4D CT data for detection tasks, even in very low dose, i.e., very high noise level, situations. In combination with the TIPS filter, the noise reduction can be increased even further.
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Affiliation(s)
- Sjoerd A M Tunissen
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ewoud J Smit
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Mikhail Mikerov
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Mathias Prokop
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Radiology, University Medical Center Groningen, Groningen, The Netherlands
| | - Ioannis Sechopoulos
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands
- Dutch Expert Centre for Screening (LRCB), Nijmegen, The Netherlands
- Technical Medicine Centre, University of Twente, Enschede, The Netherlands
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Karout L, Kalra MK. Survey of CT radiation doses and iodinated contrast medium administration: an international multicentric study. Eur Radiol 2024:10.1007/s00330-024-11017-7. [PMID: 39181948 DOI: 10.1007/s00330-024-11017-7] [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: 01/03/2024] [Revised: 06/24/2024] [Accepted: 07/15/2024] [Indexed: 08/27/2024]
Abstract
OBJECTIVE To assess the relationship between intravenous iodinated contrast media (ICM) administration usage and radiation doses for contrast-enhanced (CE) CT of head, chest, and abdomen-pelvis (AP) in international, multicenter settings. METHODS Our international (n = 16 countries), multicenter (n = 43 sites), and cross-sectional (ConRad) study had two parts. Part 1: Redcap survey with questions on information related to CT and ICM manufacturer/brand and respective protocols. Part 2: Information on 3,258 patients (18-96 years; M:F 1654:1604) who underwent CECT for a routine head (n = 456), chest (n = 528), AP (n = 599), head CT angiography (n = 539), pulmonary embolism (n = 599), and liver CT examinations (n = 537) at 43 sites across five continents. The following information was recorded: hospital name, patient age, gender, body mass index [BMI], clinical indications, scan parameters (number of scan phases, kV), IV-contrast information (concentration, volume, flow rate, and delay), and dose indices (CTDIvol and DLP). RESULTS Most routine chest (58.4%) and AP (68.7%) CECT exams were performed with 2-4 scan phases with fixed scan delay (chest 71.4%; AP 79.8%, liver CECT 50.7%) following ICM administration. Most sites did not change kV across different patients and scan phases; most CECT protocols were performed at 120-140 kV (83%, 1979/2685). There were no significant differences between radiation doses for non-contrast (CTDIvol 24 [16-30] mGy; DLP 633 [414-702] mGy·cm) and post-contrast phases (22 [19-27] mGy; 648 [392-694] mGy·cm) (p = 0.142). Sites that used bolus tracking for chest and AP CECT had lower CTDIvol than sites with fixed scan delays (p < 0.001). There was no correlation between BMI and CTDIvol (r2 ≤ - 0.1 to 0.1, p = 0.931). CONCLUSION Our study demonstrates up to ten-fold variability in ICM injection protocols and radiation doses across different CT protocols. The study emphasizes the need for optimizing CT scanning and contrast protocols to reduce unnecessary contrast and radiation exposure to patients. CLINICAL RELEVANCE STATEMENT The wide variability and lack of standardization of ICM media and radiation doses in CT protocols suggest the need for education and optimization of contrast usage and scan factors for optimizing image quality in CECT. KEY POINTS There is a lack of patient-centric CT protocol optimization taking into consideration mainly patients' size. There is a lack of correlation between ICM volume and CT radiation dose across CT protocol. A ten-fold variation in iodine-load for the same CT protocol in sites suggests a lack of standardization.
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Affiliation(s)
- Lina Karout
- Massachusetts General Hospital, Boston, MA, USA
| | - Mannudeep K Kalra
- Faculty of Applied Medical, Jordan University of Science and Technology, Irbid, Jordan.
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Pinnock MA, Hu Y, Bandula S, Barratt DC. Time conditioning for arbitrary contrast phase generation in interventional computed tomography. Phys Med Biol 2024; 69:115010. [PMID: 38697200 PMCID: PMC11103281 DOI: 10.1088/1361-6560/ad46dd] [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: 12/19/2023] [Revised: 04/16/2024] [Accepted: 05/01/2024] [Indexed: 05/04/2024]
Abstract
Minimally invasive ablation techniques for renal cancer are becoming more popular due to their low complication rate and rapid recovery period. Despite excellent visualisation, one drawback of the use of computed tomography (CT) in these procedures is the requirement for iodine-based contrast agents, which are associated with adverse reactions and require a higher x-ray dose. The purpose of this work is to examine the use of time information to generate synthetic contrast enhanced images at arbitrary points after contrast agent injection from non-contrast CT images acquired during renal cryoablation cases. To achieve this, we propose a new method of conditioning generative adversarial networks with normalised time stamps and demonstrate that the use of a HyperNetwork is feasible for this task, generating images of competitive quality compared to standard generative modelling techniques. We also show that reducing the receptive field can help tackle challenges in interventional CT data, offering significantly better image quality as well as better performance when generating images for a downstream segmentation task. Lastly, we show that all proposed models are robust enough to perform inference on unseen intra-procedural data, while also improving needle artefacts and generalising contrast enhancement to other clinically relevant regions and features.
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Affiliation(s)
- Mark A Pinnock
- Centre for Medical Image Computing, University College London, London, United Kingdom
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, London, United Kingdom
| | - Yipeng Hu
- Centre for Medical Image Computing, University College London, London, United Kingdom
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, London, United Kingdom
| | - Steve Bandula
- Centre for Medical Imaging, Division of Medicine, University College London, London, United Kingdom
- Department of Interventional Radiology, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Dean C Barratt
- Centre for Medical Image Computing, University College London, London, United Kingdom
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, London, United Kingdom
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Fan CY, Chen CH, Chen JW, Chang JH, Huang EPC, Sung CW. Chief complaints and computed tomography results in the emergency department: a three-year retrospective cohort study. BMC Emerg Med 2024; 24:87. [PMID: 38764022 PMCID: PMC11103846 DOI: 10.1186/s12873-024-01003-z] [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: 08/28/2023] [Accepted: 05/10/2024] [Indexed: 05/21/2024] Open
Abstract
BACKGROUND Computed tomography (CT) is frequently performed in the patients who admitted to the emergency department (ED), discharged but returned to ED within 72 h. It is unknown whether the main complaints of patients assist physicians to use CT effectively. This study aimed to find the association between chief complaints and the CT results. METHODS This three-year retrospective cohort study was conducted in the ED of a tertiary medical center. Adult patients who returned to the ED after the index visit were included from 2019 to 2021. Demographics, pre-existing diseases, chief complaints, and CT region were recorded by independent ED physicians. A logistic regression model with an odds ratio (OR) and 95% confidence interval (CI) was used to determine the relationship between chief complaints and positive CT results. RESULTS In total, 7,699 patients revisited ED after the index visit; 1,202 (15.6%) received CT. The top chief complaints in patients who received CT were abdominal pain, dizziness, and muscle weakness. Patients with abdominal pain or gastrointestinal symptoms had a significantly higher rate of positive abdominopelvic CT than those without it (OR 2.83, 95% CI 1.98-4.05, p < 0.001), while the central nervous system and cardiopulmonary chief complaints were not associated (or negatively associated) with new positive CT findings. CONCLUSION Chief complaints of patients on revisit to the ED are associated with different yields of new findings when CT scans of the chest, abdomen and head are performed. Physicians should consider these differential likelihoods of new positive findings based on these data.
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Affiliation(s)
- Cheng-Yi Fan
- Department of Emergency Medicine, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu, 300, Taiwan
| | - Chi-Hsin Chen
- Department of Emergency Medicine, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu, 300, Taiwan
| | - Jiun-Wei Chen
- Department of Emergency Medicine, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu, 300, Taiwan
| | - Jia-How Chang
- Department of Emergency Medicine, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu, 300, Taiwan
- Department of Emergency Medicine, College of Medicine, National Taiwan University, Taipei, 100, Taiwan
| | - Edward Pei-Chuan Huang
- Department of Emergency Medicine, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu, 300, Taiwan
- Department of Emergency Medicine, National Taiwan University Hospital, Taipei, 100, Taiwan
- Department of Emergency Medicine, College of Medicine, National Taiwan University, Taipei, 100, Taiwan
| | - Chih-Wei Sung
- Department of Emergency Medicine, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu, 300, Taiwan.
- Department of Emergency Medicine, College of Medicine, National Taiwan University, Taipei, 100, Taiwan.
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Schüle S, Bunert F, Hackenbroch C, Beer M, Ostheim P, Stewart S, Port M, Scherthan H, Abend M. The Influence of Computed Tomography Contrast Agent on Radiation-Induced Gene Expression and Double-Strand Breaks. Radiat Res 2024; 201:396-405. [PMID: 38282002 DOI: 10.1667/rade-23-00118.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 10/14/2023] [Indexed: 01/30/2024]
Abstract
After nuclear scenarios, combined injuries of acute radiation syndrome (ARS) with, e.g., abdominal trauma, will occur and may require contrast-enhanced computed tomography (CT) scans for diagnostic purposes. Here, we investigated the effect of iodinated contrast agents on radiation-induced gene expression (GE) changes used for biodosimetry (AEN, BAX, CDKN1A, EDA2R, APOBEC3H) and for hematologic ARS severity prediction (FDXR, DDB2, WNT3, POU2AF1), and on the induction of double-strand breaks (DSBs) used for biodosimetry. Whole blood samples from 10 healthy donors (5 males, 5 females, mean age: 28 ± 2 years) were irradiated with X rays (0, 1 and 4 Gy) with and without the addition of iodinated contrast agent (0.016 ml contrast agent/ml blood) to the blood prior to the exposure. The amount of contrast agent was set to be equivalent to the blood concentration of an average patient (80 kg) during a contrast-enhanced CT scan. After irradiation, blood samples were incubated at 37°C for 20 min (DSB) and 8 h (GE, DSB). GE was measured employing quantitative real-time polymerase chain reaction. DSB foci were revealed by γH2AX + 53BP1 immunostaining and quantified automatically in >927 cells/sample. Radiation-induced differential gene expression (DGE) and DSB foci were calculated using the respective unexposed sample without supplementation of contrast agent as the reference. Neither the GE nor the number of DSB foci was significantly (P = 0.07-0.94) altered by the contrast agent application. However, for some GE and DSB comparisons with/without contrast agent, there were weakly significant differences (P = 0.03-0.04) without an inherent logic and thus are likely due to inter-individual variation. In nuclear events, the diagnostics of combined injuries can require the use of an iodinated contrast agent, which, according to our results, does not alter or influence radiation-induced GE changes and the quantity of DSB foci. Therefore, the gene expression and γH2AX focus assay can still be applied for biodosimetry and/or hematologic ARS severity prediction in such scenarios.
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Affiliation(s)
- Simone Schüle
- Bundeswehr Institute of Radiobiology affiliated to the University of Ulm, Neuherbergstraße 11, 80937 Munich, Germany
- Department of Diagnostic and Interventional Radiology and Neuroradiology, German Armed Force Hospital of Ulm, Oberer Eselsberg 40, 89081 Ulm, Germany
| | - Felix Bunert
- Bundeswehr Institute of Radiobiology affiliated to the University of Ulm, Neuherbergstraße 11, 80937 Munich, Germany
| | - Carsten Hackenbroch
- Department of Diagnostic and Interventional Radiology and Neuroradiology, German Armed Force Hospital of Ulm, Oberer Eselsberg 40, 89081 Ulm, Germany
- Department of Radiology, University Hospital of Ulm, Albert-Einstein-Allee 23, 89081 Ulm, Germany
| | - Meinrad Beer
- Department of Radiology, University Hospital of Ulm, Albert-Einstein-Allee 23, 89081 Ulm, Germany
| | - Patrick Ostheim
- Bundeswehr Institute of Radiobiology affiliated to the University of Ulm, Neuherbergstraße 11, 80937 Munich, Germany
- Department of Radiology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg
| | - Samantha Stewart
- Bundeswehr Institute of Radiobiology affiliated to the University of Ulm, Neuherbergstraße 11, 80937 Munich, Germany
| | - Matthias Port
- Bundeswehr Institute of Radiobiology affiliated to the University of Ulm, Neuherbergstraße 11, 80937 Munich, Germany
| | - Harry Scherthan
- Bundeswehr Institute of Radiobiology affiliated to the University of Ulm, Neuherbergstraße 11, 80937 Munich, Germany
| | - Michael Abend
- Bundeswehr Institute of Radiobiology affiliated to the University of Ulm, Neuherbergstraße 11, 80937 Munich, Germany
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Sperry BW, Vamenta MS, Gunta SP, Thompson RC, Einstein AJ, Castillo M, Chaudhary PD, Bremner LI, Cohen YA, Bateman TM, McGhie AI. Influence of Body Mass Index on Radiation Exposure Across Imaging Modalities in the Evaluation of Chest Pain. J Am Heart Assoc 2024; 13:e033566. [PMID: 38591342 PMCID: PMC11262536 DOI: 10.1161/jaha.123.033566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 03/07/2024] [Indexed: 04/10/2024]
Abstract
BACKGROUND Essential to a patient-centered approach to imaging individuals with chest pain is knowledge of differences in radiation effective dose across imaging modalities. Body mass index (BMI) is an important and underappreciated predictor of effective dose. This study evaluated the impact of BMI on estimated radiation exposure across imaging modalities. METHODS AND RESULTS This was a retrospective analysis of patients with concern for cardiac ischemia undergoing positron emission tomography (PET)/computed tomography (CT), cadmium zinc telluride single-photon emission CT (SPECT) myocardial perfusion imaging, or coronary CT angiography (CCTA) using state-of-the-art imaging modalities and optimal radiation-sparing protocols. Radiation exposure was calculated across BMI categories based on established cardiac imaging-specific conversion factors. Among 9046 patients (mean±SD age, 64.3±13.1 years; 55% men; mean±SD BMI, 30.6±6.9 kg/m2), 4787 were imaged with PET/CT, 3092 were imaged with SPECT/CT, and 1167 were imaged with CCTA. Median (interquartile range) radiation effective doses were 4.4 (3.9-4.9) mSv for PET/CT, 4.9 (4.0-6.3) mSv for SPECT/CT, and 6.9 (4.0-11.2) mSv for CCTA. Patients at a BMI <20 kg/m2 had similar radiation effective dose with all 3 imaging modalities, whereas those with BMI ≥20 kg/m2 had the lowest effective dose with PET/CT. Radiation effective dose and variability increased dramatically with CCTA as BMI increased, and was 10 times higher in patients with BMI >45 kg/m2 compared with <20 kg/m2 (median, 26.9 versus 2.6 mSv). After multivariable adjustment, PET/CT offered the lowest effective dose, followed by SPECT/CT, and then CCTA (P<0.001). CONCLUSIONS Although median radiation exposure is modest across state-of-the-art PET/CT, SPECT/CT, and CCTA systems using optimal radiation-sparing protocols, there are significant variations across modalities based on BMI. These data are important for making patient-centered decisions for ischemic testing.
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Affiliation(s)
- Brett W. Sperry
- Saint Luke’s Mid America Heart InstituteKansas CityMO
- University of Missouri–Kansas CityKansas CityMO
| | - Mary Stefanie Vamenta
- Saint Luke’s Mid America Heart InstituteKansas CityMO
- University of Missouri–Kansas CityKansas CityMO
| | | | - Randall C. Thompson
- Saint Luke’s Mid America Heart InstituteKansas CityMO
- University of Missouri–Kansas CityKansas CityMO
| | - Andrew J. Einstein
- Seymour, Paul and Gloria Milstein Division of CardiologyNew YorkNY
- Department of MedicineMailman School of Public Health at Columbia University Irving Medical Center/New York Presbyterian HospitalNew YorkNY
- Department of RadiologyMailman School of Public Health at Columbia University Irving Medical Center/New York Presbyterian HospitalNew YorkNY
| | - Michelle Castillo
- Seymour, Paul and Gloria Milstein Division of CardiologyNew YorkNY
- Department of MedicineMailman School of Public Health at Columbia University Irving Medical Center/New York Presbyterian HospitalNew YorkNY
| | - Priyanka D. Chaudhary
- Department of RadiologyMailman School of Public Health at Columbia University Irving Medical Center/New York Presbyterian HospitalNew YorkNY
| | - Luca I. Bremner
- Seymour, Paul and Gloria Milstein Division of CardiologyNew YorkNY
- Vagelos College of Physicians and SurgeonsMailman School of Public Health at Columbia University Irving Medical Center/New York Presbyterian HospitalNew YorkNY
| | - Yosef A. Cohen
- Seymour, Paul and Gloria Milstein Division of CardiologyNew YorkNY
- Department of MedicineMailman School of Public Health at Columbia University Irving Medical Center/New York Presbyterian HospitalNew YorkNY
- Mailman School of Public Health at Columbia University Irving Medical Center/New York Presbyterian HospitalNew YorkNY
| | - Timothy M. Bateman
- Saint Luke’s Mid America Heart InstituteKansas CityMO
- University of Missouri–Kansas CityKansas CityMO
| | - A. Iain McGhie
- Saint Luke’s Mid America Heart InstituteKansas CityMO
- University of Missouri–Kansas CityKansas CityMO
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Sauer TJ, McCabe C, Abadi E, Samei E, Segars WP. Surface-based anthropomorphic bone structures for use in high-resolution simulated medical imaging. Phys Med Biol 2023; 69:10.1088/1361-6560/ad1275. [PMID: 38052093 PMCID: PMC10792658 DOI: 10.1088/1361-6560/ad1275] [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: 06/16/2023] [Accepted: 12/05/2023] [Indexed: 12/07/2023]
Abstract
Objective.Virtual imaging trials enable efficient assessment and optimization of medical image devices and techniques via simulation rather than physical studies. These studies require realistic, detailed ground-truth models or phantoms of the relevant anatomy or physiology. Anatomical structures within computational phantoms are typically based on medical imaging data; however, for small and intricate structures (e.g. trabecular bone), it is not reasonable to use existing clinical data as the spatial resolution of the scans is insufficient. In this study, we develop a mathematical method to generate arbitrary-resolution bone structures within virtual patient models (XCAT phantoms) to model the appearance of CT-imaged trabecular bone.Approach. Given surface definitions of a bone, an algorithm was implemented to generate stochastic bicontinuous microstructures to form a network to define the trabecular bone structure with geometric and topological properties indicative of the bone. For an example adult male XCAT phantom (50th percentile in height and weight), the method was used to generate the trabecular structure of 46 chest bones. The produced models were validated in comparison with published properties of bones. The utility of the method was demonstrated with pilot CT and photon-counting CT simulations performed using the accurate DukeSim CT simulator on the XCAT phantom containing the detailed bone models.Main results. The method successfully generated the inner trabecular structure for the different bones of the chest, having quantiative measures similar to published values. The pilot simulations showed the ability of photon-counting CT to better resolve the trabecular detail emphasizing the necessity for high-resolution bone models.Significance.As demonstrated, the developed tools have great potential to provide ground truth simulations to access the ability of existing and emerging CT imaging technology to provide quantitative information about bone structures.
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Affiliation(s)
- Thomas J Sauer
- Center for Virtual Imaging Trials, Duke University, Durham NC, United States of America
| | - Cindy McCabe
- Center for Virtual Imaging Trials, Duke University, Durham NC, United States of America
| | - Ehsan Abadi
- Center for Virtual Imaging Trials, Duke University, Durham NC, United States of America
| | - Ehsan Samei
- Center for Virtual Imaging Trials, Duke University, Durham NC, United States of America
| | - W Paul Segars
- Center for Virtual Imaging Trials, Duke University, Durham NC, United States of America
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Leiknes JB, Hiorth A, Havnen J, Greve OJ, Kurz KD, Larsen AI. Estimating cardiac output from coronary CT angiography: an individualized compartment model in comparison to the Stewart-Hamilton method. Front Cardiovasc Med 2023; 10:1156332. [PMID: 38054087 PMCID: PMC10694230 DOI: 10.3389/fcvm.2023.1156332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 10/10/2023] [Indexed: 12/07/2023] Open
Abstract
Background Attenuation is correlated with the concentration of contrast medium (CM) in the arteries. The cardiac output (CO) affects the concentration of CM in the circulatory system; therefore, CO affects the time-density curve (TDC). Thus, estimating CO using TDC from test-bolus images acquired in computed tomography (CT) is possible. In this study, we compare two methods of estimating CO, namely, an individualized mathematical compartment model, integrating patient, contrast, and scanning factors with TDC, and the Stewart-Hamilton method based on the area under the curve of the TDC. Materials and methods Attenuation in the aorta was measured during test-bolus in 40 consecutive patients with a clinical indication for coronary CT angiography (CCTA). Each participant underwent cardiac magnetic resonance imaging following CCTA to validate the estimated CO. The individual compartment model used TDC in conjunction with scanning and patient-specific parameters to estimate the concentration of CM and CO over time. This was compared to the CO calculated from the area under the curve using the Stewart-Hamilton method. Results Both CO estimated with our individualized compartment model (r = 0.66, p < 0.01) and the Stewart-Hamilton method (r = 0.53, p < 0.01) were moderately correlated with CO measured with cardiac MRI. Body surface area (BSA) and time to peak (TTP) affected the accuracy of our model. Lower BSA resulted in overestimation, and lower TTP resulted in CO underestimation, respectively. We found no gender-specific difference in the accuracy of our model when correcting for BSA. The Stewart-Hamilton method performed better with a more complete TDC, whereas the compartment model performed better overall with a partial TDC. Conclusion The TDC acquired in CCTA allows for CO estimation. Both the Stewart-Hamilton method and our mathematical compartment model show moderate correlation when applied to our data, although each method has its strengths and limitations. If the majority of the TDC is known, the Stewart-Hamilton method may be more reliable, but an individual compartment model is preferable when there are insufficient data points in the TDC. Regardless, both methods can potentially increase the diagnostic information acquired from a CCTA, which is increasingly recommended in clinical guidelines.
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Affiliation(s)
- Jon Bjarne Leiknes
- Stavanger Medical Imaging Laboratory, Department of Radiology, Stavanger University Hospital, Stavanger, Norway
- Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Aksel Hiorth
- Department of Energy Resources, University of Stavanger, Stavanger, Norway
| | - Jorunn Havnen
- Stavanger Medical Imaging Laboratory, Department of Radiology, Stavanger University Hospital, Stavanger, Norway
| | - Ole Jacob Greve
- Stavanger Medical Imaging Laboratory, Department of Radiology, Stavanger University Hospital, Stavanger, Norway
| | - Kathinka Dæhli Kurz
- Stavanger Medical Imaging Laboratory, Department of Radiology, Stavanger University Hospital, Stavanger, Norway
- Department of Electrical Engineering and Computer Science, University of Stavanger, Stavanger, Norway
| | - Alf Inge Larsen
- Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Cardiology, Stavanger University Hospital, Stavanger, Norway
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Myronakis M, Stratakis J, Damilakis J. Rapid estimation of patient-specific organ doses using a deep learning network. Med Phys 2023; 50:7236-7244. [PMID: 36918360 DOI: 10.1002/mp.16356] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 01/23/2023] [Accepted: 02/26/2023] [Indexed: 03/16/2023] Open
Abstract
BACKGROUND Patient-specific organ-dose estimation in diagnostic CT examinations can provide useful insights on individualized secondary cancer risks, protocol optimization, and patient management. Current dose estimation techniques mainly rely on time-consuming Monte Carlo methods or/and generalized anthropomorphic phantoms. PURPOSE We proposed a proof-of-concept rapid workflow based on deep learning networks to estimate organ doses for individuals following thorax Computed Tomography (CT) examinations. METHODS CT scan data from 95 individuals undergoing thorax CT examinations were used. Monte Carlo simulations were performed and three-dimensional (3D) dose distributions for each patient were obtained. A fully connected sequential deep learning network model was constructed and trained for each organ considered in this study. Water-equivalent diameter (WED), scan length, and tube current were the independent variables. Organ doses for heart, lungs, esophagus, and bones were calculated from the Monte Carlo 3D distribution and used to train the deep learning networks. Organ dose predictions from each network were evaluated using an independent data set of 19 patients. RESULTS The trained networks provided organ dose predictions within a second. There was very good agreement between the deep learning network predictions and reference organ dose values calculated from Monte Carlo simulations. The average difference was -1.5% for heart, -1.6% for esophagus, -1.0% for lungs, and -0.4% for bones in the 95 patients dataset, and -5.1%, 4.3%, 0.9%, and 1.4% respectively in the 19 patients test dataset. CONCLUSIONS The proposed workflow demonstrated that patient-specific organ-doses can be estimated in nearly real-time using deep learning networks. The workflow can be readily implemented and requires a small set of representative data for training.
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Affiliation(s)
- Marios Myronakis
- Department of Medical Physics, School of Medicine, University of Crete, Iraklion, Greece
| | - John Stratakis
- Department of Medical Physics, School of Medicine, University of Crete, Iraklion, Greece
- Medical Physics Department, University Hospital of Crete, Iraklion, Greece
| | - John Damilakis
- Department of Medical Physics, School of Medicine, University of Crete, Iraklion, Greece
- Medical Physics Department, University Hospital of Crete, Iraklion, Greece
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10
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Mazloumi M, Van Gompel G, Tanaka K, Argacha JF, de Mey J, Buls N. The impact of iodine contrast agent on radiation dose of heart and blood: a comparison between coronary CT angiography and cardiac calcium scoring CT. Acta Radiol 2023; 64:2387-2392. [PMID: 37138465 DOI: 10.1177/02841851231170850] [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] [Indexed: 05/05/2023]
Abstract
BACKGROUND Iodine contrast agent (CA) is widely used in cardiac computed tomography (CT). The CA can increase the organ radiation doses due to the photoelectric effect. PURPOSE To investigate the impact of CA on radiation dose in cardiac CT by comparing the radiation dose between contrast coronary CT angiography (CCTA) and non-contrast calcium scoring CT (CSCT). MATERIAL AND METHODS Radiation doses were computationally calculated for 30 individual patients who received CSCT and CCTA in the same exam session. The geometry and acquisition parameters were modeled in the simulations based on individual patient CT images and acquisitions. Doses in the presence and absence of CA were obtained in the aorta, left ventricle (LV), right ventricle (RV), and myocardial tissue (MT). The dose values were normalized by size-specific dose estimate (SSDE). The dose enhancement factors (DEFSSDE) were calculated as the ratio of doses in CCTA over doses in CSCT. RESULTS Compared to the CSCT scans, doses increase in the CCTA scans in the aorta (DEFSSDE = 2.14 ± 0.20), LV (DEFSSDE = 1.78 ± 0.26), and RV (DEFSSDE = 1.31 ± 0.22). A linear relation is observed between the local CA concentrations and the dose increase in the heart; DEFSSDE = 0.07*I(mg/mL) + 0.80 (R2 = 0.8; p < 0.01). The DEFSSDE in the MT (DEFSSDE = 0.96 ± 0.08) showed no noticeable impact of CA on the dose in this tissue. In addition, patient variability in the dose distributions was observed. CONCLUSION A linear causal relation exists between local CA concentration and increase in radiation dose in cardiac CT. For the same CT exposure, dose to the heart is on average 55% higher in contrast cardiac CT.
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Affiliation(s)
- Mahta Mazloumi
- Department of Radiology, Vrije Universiteit Brussel, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
| | - Gert Van Gompel
- Department of Radiology, Vrije Universiteit Brussel, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
| | - Kaoru Tanaka
- Department of Radiology, Vrije Universiteit Brussel, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
| | - Jean-François Argacha
- Department of Cardiology, Vrije Universiteit Brussel, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
| | - Johan de Mey
- Department of Radiology, Vrije Universiteit Brussel, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
| | - Nico Buls
- Department of Radiology, Vrije Universiteit Brussel, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
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11
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Salah H, Rabbaa M, Abuljoud M, Babikir E, Alkhorayef M, Tamam N, Tahir D, Sulieman A, Bradley DA. Paediatric effective radiation doses during brain computed tomography angiography procedure. Appl Radiat Isot 2023; 192:110610. [PMID: 36525913 DOI: 10.1016/j.apradiso.2022.110610] [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: 02/17/2022] [Revised: 12/06/2022] [Accepted: 12/06/2022] [Indexed: 12/12/2022]
Abstract
In comparison to adults and paediatric are more sensitive to ionizing radiation exposure. Computed tomography (CT) is now the dominant source of medical radiologic tests for patients, accounting for more than 70% of total doses to the general public. Paediatric CT brain scans (with and without contrast) are routinely performed for a variety of clinical reasons. As a result, this parameter must be calculated in order to determine relative radiation risk. The goal of this study is to assess the radiation risk to children during CT brain diagnostic procedures. Three hundred fifty three child patients' radiation risk doses were assessed over the course of a year. The mean and ranged of the children's radiation doses were 40.6 ± 8.8 (27.8-45.8) CTDIvol (mGy) and 850 ± 230 (568.1-1126.4) DLP (mGy.cm) for the brain with contrast medium. For CT brain without contrast, the patients' doses were 40.9 ± 9.4 (14.27-64.07) CTDIvol (mGy), and 866.1 ± 289.3 (203.6-2484.9) DLP (mGy.cm). The characteristics related to the radiation dose were retrieved from the scan protocol generated by the CT system by the participating physicians after each procedure. Furthermore, optimizing the CT acquisition parameter is critical for increasing the benefit while lowering the procedure's radiogenic risk. The patients' radiation dose is comparable with the most previously published studies and international diagnostic reference levels (DRLs). Radiation dose optimization is recommended due to high sensitivity of the paediatric patients to ionizing radiation.
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Affiliation(s)
- H Salah
- INAYA Medical Collage, Nuclear Medicine Department, Riyadh, Saudi Arabia; College of Medical Radiologic Science, Sudan University of Science and Technology, Khartoum, Sudan.
| | - Mohammad Rabbaa
- Radiology Department, Riyadh Care Hospital, Riyadh, Saudi Arabia
| | | | - E Babikir
- Radiologic Technology Program, College of Health and Sport Sciences, University of Bahrain, Sakhir Campus, Zallaq, P.O. Box 32038, Bahrain
| | - M Alkhorayef
- Department of Radiological Sciences, College of Applied Medical Sciences, King Saud University, P.O Box 10219, Riyadh, 11433, Saudi Arabia
| | - N Tamam
- Department of Physics, College of Sciences, Princess Nourah bint Abdulrahman University, P.O Box 84428, Riyadh, 11671, Saudi Arabia
| | - Dahlang Tahir
- Department of Physics, Hasanuddin University, Makassar, 90245, Indonesia
| | - A Sulieman
- Prince Sattam bin Abdulaziz University, College of Applied Medical Sciences, Radiology and Medical Imaging Department, P.O. Box 422, Alkharj, 11942, Saudi Arabia
| | - D A Bradley
- Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford, United Kingdom; Centre for Applied Physics and Radiation Technologies, School of Engineering and Technology, Sunway University, 47500, Bandar Sunway, Selangor, Malaysia
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12
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Bae JS, Lee JM, Kim SW, Park S, Han S, Yoon JH, Joo I, Hong H. Low-contrast-dose liver CT using low monoenergetic images with deep learning-based denoising for assessing hepatocellular carcinoma: a randomized controlled noninferiority trial. Eur Radiol 2022; 33:4344-4354. [PMID: 36576547 DOI: 10.1007/s00330-022-09298-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 09/29/2022] [Accepted: 11/13/2022] [Indexed: 12/29/2022]
Abstract
OBJECTIVE Low monoenergetic images obtained using noise-reduction techniques may reduce CT contrast media requirements. We aimed to investigate the effectiveness of low-contrast-dose CT using dual-energy CT and deep learning-based denoising (DLD) techniques in patients at high risk of hepatocellular carcinoma (HCC). METHODS We performed a prospective, randomized controlled noninferiority trial at a tertiary hospital between June 2019 and August 2020 (NCT04027556). Patients at high risk of HCC were randomly assigned (1:1) to the standard-contrast-dose group or low-contrast-dose group, which targeted a 40% reduction in contrast medium dose based on lean body weight. HCC conspicuity on arterial phase images was the primary endpoint with a noninferiority margin of 0.2. Images were independently assessed by three radiologists; model-based iterative reconstruction (MBIR) images of the standard-contrast-dose group and low monoenergetic (50-keV) DLD images of the low-contrast-dose group were compared using a generalized estimating equation. RESULTS Ninety participants (age 59 ± 10 years; 68 men) were analyzed. Compared with the standard-contrast-dose group (n = 47), 40% less contrast media was used in the low-contrast-dose group (n = 43) (107.0 ± 17.1 mL vs. 64.5 ± 11.3 mL, p < 0.001). In the arterial phase, HCC conspicuity on 50-keV DLD images in the low-contrast-dose group was noninferior to that of MBIR images in the standard-contrast-dose group (2.92 vs. 2.56; difference, 0.36; 95% confidence interval, -0.13 to ∞; p = 0.013). CONCLUSIONS The contrast dose in liver CT can be reduced by 40% without impairing HCC conspicuity when using 50-keV and DLD techniques. KEY POINTS • In the arterial phase, hepatocellular carcinoma conspicuity on 50-keV deep learning-based denoising images in the low-contrast-dose group was noninferior to that of model-based iterative reconstruction images in the standard-contrast-dose group. • HCC detection was comparable between 50-keV deep learning-based denoising images in the low-contrast-dose group and model-based iterative reconstruction images in the standard-contrast-dose group.
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Affiliation(s)
- Jae Seok Bae
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Jeong Min Lee
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea. .,Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea. .,Institute of Radiation Medicine, Seoul National University Medical Research Center, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
| | - Se Woo Kim
- Department of Radiology, Armed Forces Daejeon Hospital, 90, Jaun-ro, Yuseong-gu, Daejeon, 34059, Republic of Korea
| | - Sungeun Park
- Department of Radiology, Konkuk University Medical Center, 120-1, Neungdong-ro, Gwangjin-gu, Seoul, 05030, Republic of Korea
| | - Seungchul Han
- Department of Radiology, Samsung Medical Center, 81, Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea
| | - Jeong Hee Yoon
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Ijin Joo
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Hyunsook Hong
- Division of Biostatistics, Medical Research Collaborating Center, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
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13
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Imai K, Takeda K, Fujii K, Kawaura C, Nishimoto T, Mori M, Yamamoto Y, Izumi T. Relationship between Dilution Magnification of Non-Ionic Iodinated Contrast Medium and Amplification Effect of Radiation Dose. JOURNAL OF NEUROENDOVASCULAR THERAPY 2022; 16:586-592. [PMID: 37502666 PMCID: PMC10370713 DOI: 10.5797/jnet.oa.2022-0041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 09/02/2022] [Indexed: 07/29/2023]
Abstract
Objective Neuroendovascular treatments are less invasive than surgical clipping. However, the number of fluoroscopy runs may be greater when a contrast medium is used than when routine angiography is performed. Several recent studies have suggested that an iodinated contrast medium causes an increase in the radiation dose. Therefore, it is clinically important to identify physical factors causing amplification of the radiation dose. The purpose of this study was to investigate how dilution of a contrast medium with water influences the amplification effect of the radiation dose using simulation analysis. Methods Three different types of commercially available contrast media, namely, iopamidol, iohexol, and iodixanol, were diluted 1.7-3.3 times with water and placed in the left brain parenchyma of a numerical brain phantom. Using the Monte Carlo simulation method, the phantom was exposed to X-ray beams under constant exposure conditions, and the energy absorbed in the entire region of the left brain parenchyma was estimated. At the same time, the content and volume of a contrast medium in the cerebral vessels were predicted on the basis of pharmacokinetic and fractal analyses. Results The increase in absorbed energy was attributed to secondary electrons emitted from the contrast medium and varied depending on its content and volume. Interestingly, the amount of energy absorbed increased with increasing dilution of the contrast medium. Furthermore, the amplification effect of the radiation dose varied according to the type of contrast medium used. Conclusion These results suggest that the amplification effect of the radiation dose is closely related to an increase in the cross-sectional area in which the X-rays interact with the contrast medium, which is caused by increased distribution of contrast medium in the cerebral vessels. When the contrast medium is diluted with water, its spread in the cerebral vessels plays a more important role than its content in the amplification effect of the radiation dose.
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Affiliation(s)
- Kuniharu Imai
- Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Kento Takeda
- Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Keisuke Fujii
- Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Chiyo Kawaura
- Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Takuya Nishimoto
- Division of Radiological Technology, Nagoya University Hospital, Nagoya, Aichi, Japan
| | - Masaki Mori
- Division of Radiological Technology, Nagoya University Hospital, Nagoya, Aichi, Japan
| | - Yuki Yamamoto
- Division of Radiological Technology, Fujita Health University Okazaki Medical Center, Nagoya, Aichi, Japan
| | - Takashi Izumi
- Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
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14
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Contrast Medium Use in Computed Tomography for Patients Presenting with Headache: 4-year Retrospective Two-Center Study in Central and Western Regions of Ghana. Radiol Res Pract 2022; 2022:4736455. [PMID: 36248021 PMCID: PMC9553476 DOI: 10.1155/2022/4736455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 08/04/2022] [Accepted: 09/14/2022] [Indexed: 11/17/2022] Open
Abstract
Background Contrast medium (CM) administration during computed tomography (CT) enhances the accuracy in the detection and interpretation of abnormalities. Evidence from literature also validate the essence of CM in imaging studies. CT, by virtue of its ubiquity, ease of use, speed, and lower financial footprint, is usually the first investigation in cases of headache. Through a multicenter retrospective analysis, we compared findings of contrast-enhanced CT (CECT) to noncontrast-enhanced CT (NCECT) head examinations among patients presenting with headache. Methods A multicenter retrospective analysis of four years' CT head examination data at two radiology centers located in Central and Western Regions of Ghana were reviewed. Records of patients who presented with headache as principal complaint between January 2017 and December 2020 were reviewed. A total of 477 records of patients with headache were identified, retrieved and evaluated. A Chi-square test and Fisher exact test were used to compare the CECT and NCECT groups. Binary logistic regression analysis was computed to assess association between CECT and each CT findings. Statistical significance was considered at p < 0.05 with a 95% confidence interval. Results A significant proportion of the patients was females (51.8% in CECT and 60% in NCECT). The NCECT group (40.06 ± 14.76 years) was relatively older than the CECT group (38.43 ± 17.64 years). There was a significant difference between the CECT and NCECT in terms of age (p=0.002) and facility CT was performed (p < 0.0001). The rate of abnormalities was higher in CECT (43.5%, 166/382) compared NCECT (37.9%, 36/95). There was no significant association between CT head findings and contrast enhancement. Conclusion CECT examination accounted for 5.6% increase in the detection of head abnormalities. Efforts required to establish local standard operation procedures (SOPs) for contrast medium use especially in CT head examinations. Further studies to improve the knowledge of agents, mechanism of action, and safety of contrast media used among practitioners in Ghana is recommended.
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15
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Kul M, Kuru Öz D, Gürsoy Coruh A, Özalp Ateş F, Gülpınar B, Uzun Ç, Atasoy K. Biphasic split-bolus injection protocol for routine contrast-enhanced chest CT: comparison with conventional early-phase single bolus technique. Br J Radiol 2022; 95:20210775. [PMID: 35171718 PMCID: PMC10996411 DOI: 10.1259/bjr.20210775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 02/03/2022] [Accepted: 02/08/2022] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To present a routine contrast-enhanced chest CT protocol with a split-bolus injection technique achieving combined early- and delayed phase images with a single aquisition, and to compare this technique with a conventional early-phase single-bolus chest CT protocol we formerly used at our institution, in terms of attenuation of great thoracic vessels, pleura, included hepatic and portal venous enhancement, contrast-related artifacts, and image quality. METHODS A total of 202 patients, who underwent routine contrast-enhanced chest CT examination aquired with either conventional early-phase single-bolus technique (group A,n = 102) or biphasic split-bolus protocol (group B,n = 100), were retrospectively included. Attenuation measurements were made by two radiologists independently on mediastinal window settings using a circular ROI at the following sites: main pulmonary artery (PA) at its bifurcation level, thoracal aorta (TA) at the level of MPA bifurcation,portal vein (PV) at porta hepatis, left and right hepatic lobe, and if present, thickened pleura (>2 mm) at the level with the most intense enhancement. Respective normalized enhancement values were also calculated. Contrast-related artifacts were graded and qualitative evaluation of mediastinal lymph nodes was performed by both reviewers independently. Background noise was measured and contrast-to-noise ratios (CNRs) of the liver and TA were calculated. RESULTS While enhancement of thoracic vessels and normalised MPA enhancement did not differ significantly between both groups (p > 0.05), enhancement and normalised enhancement of pleura, liver parenchyma and PV was significantly greater in group B (p < 0.001). Perivenous artifacts limiting evaluation were less frequent in group B than in A and mediastinal lymph nodes were judged to be evaluated worse in group A than in group B with an excellent agreement between both observers. No significant difference was detected in CNRTA (p = 0.633), whereas CNR liver was higher in group B (p < 0.001). CONCLUSION Our split-bolus chest CT injection protocol enables simultaneous enhancement for both vascular structures and soft tissues, and thus, might raise diagnostic confidence without the need of multiple acquisitions. ADVANCES IN KNOWLEDGE We think that this CT protocol might also be a promising alternative in lung cancer staging, where combined contrast-enhanced CT of the chest and abdomen is indicated. We therefore suggest to further evaluate its diagnostic utility in this setting, in particular in comparison with a late delayed chest-upper abdominal CT imaging protocol.
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Affiliation(s)
- Melahat Kul
- Department of Radiology, School of Medicine, Ankara
University, Ankara,
Turkey
| | - Diğdem Kuru Öz
- Department of Radiology, School of Medicine, Ankara
University, Ankara,
Turkey
| | | | - Funda Özalp Ateş
- Department of Biostatistics, School of Medicine, Manisa Celal
Bayar University, Manisa,
Turkey
| | - Başak Gülpınar
- Department of Radiology, School of Medicine, Ankara
University, Ankara,
Turkey
| | - Çağlar Uzun
- Department of Radiology, School of Medicine, Ankara
University, Ankara,
Turkey
| | - K.Çetin Atasoy
- Department of Radiology, School of Medicine, Koç
University, İstanbul,
Turkey
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16
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Sauer TJ, Abadi E, Segars P, Samei E. Anatomically and physiologically informed computational model of hepatic contrast perfusion for virtual imaging trials. Med Phys 2022; 49:2938-2951. [PMID: 35195901 PMCID: PMC9547339 DOI: 10.1002/mp.15562] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 02/02/2022] [Accepted: 02/02/2022] [Indexed: 12/10/2022] Open
Abstract
PURPOSE Virtual (in silico) imaging trials (VITs), involving computerized phantoms and models of the imaging process, provide a modern alternative to clinical imaging trials. VITs are faster, safer, and enable otherwise-impossible investigations. Current phantoms used in VITs are limited in their ability to model functional behavior such as contrast perfusion which is an important determinant of dose and image quality in CT imaging. In our prior work with the XCAT computational phantoms, we determined and modeled inter-organ (organ to organ) intravenous contrast concentration as a function of time from injection. However, intra-organ concentration, heterogeneous distribution within a given organ, was not pursued. We extend our methods in this work to model intra-organ concentration within the XCAT phantom with a specific focus on the liver. METHODS Intra-organ contrast perfusion depends on the organ's vessel network. We modeled the intricate vascular structures of the liver, informed by empirical and theoretical observations of anatomy and physiology. The developed vessel generation algorithm modeled a dual-input-single-output vascular network as a series of bifurcating surfaces to optimally deliver flow within the bounding surface of a given XCAT liver. Using this network, contrast perfusion was simulated within voxelized versions of the phantom by using knowledge of the blood velocities in each vascular structure, vessel diameters and length, and the time since the contrast entered the hepatic artery. The utility of the enhanced phantom was demonstrated through a simulation study with the phantom voxelized prior to CT simulation with the relevant liver vasculature prepared to represent blood and iodinated contrast media. The spatial extent of the blood-contrast mixture was compared to clinical data. RESULTS The vascular structures of the liver were generated with size and orientation which resulted in minimal energy expenditure required to maintain blood flow. Intravenous contrast was simulated as having known concentration and known total volume in the liver as calibrated from time-concentration curves. Measurements of simulated CT ROIs were found to agree with clinically observed values of early arterial phase contrast enhancement of the parenchyma (∼ 5 $ \sim 5$ HU). Similarly, early enhancement in the hepatic artery was found to agree with average clinical enhancement( 180 $(180$ HU). CONCLUSIONS The computational methods presented here furthered the development of the XCAT phantoms allowing for multi-timepoint contrast perfusion simulations, enabling more anthropomorphic virtual clinical trials intended for optimization of current clinical imaging technologies and applications.
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Affiliation(s)
- Thomas J. Sauer
- Center for Virtual Imaging Trials (CVIT), Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center
| | - Ehsan Abadi
- Center for Virtual Imaging Trials (CVIT), Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center
| | - Paul Segars
- Center for Virtual Imaging Trials (CVIT), Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center
| | - Ehsan Samei
- Center for Virtual Imaging Trials (CVIT), Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center
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17
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Fischer AM, Decker JA, Schoepf J, Varga-Szemes A, Flohr T, Schmidt B, Gutjahr R, Sahbaee P, Giovagnoli DA, Emrich T, Martinez JD, Lari KB, Bayer RR, Martin SS. Optimization of contrast material administration for coronary CT angiography using a software-based test-bolus evaluation algorithm. Br J Radiol 2022; 95:20201456. [PMID: 35084228 PMCID: PMC10993975 DOI: 10.1259/bjr.20201456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 11/23/2021] [Accepted: 01/12/2022] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To evaluate the benefit of a prototype circulation time-based test bolus evaluation algorithm for the individualized optimal timing of contrast media (CM) delivery in patients undergoing coronary CT angiography (CCTA). METHODS Thirty-two patients (62 ± 16 years) underwent CCTA using a prototype bolus evaluation tool to determine the optimal time-delay for CM administration. Contrast attenuation, signal-to-noise ratio (SNR), objective, and subjective image quality were evaluated by two independent radiologists. Results were compared to a control cohort (matched for age, sex, body mass index, and tube voltage) of patients who underwent CCTA using the generic test bolus peak attenuation +4 s protocol as scan delay. RESULTS In the study group, the mean time delay to CCTA acquisition was significantly longer (26.0 ± 2.9 s) compared to the control group (23.1 ± 3.5 s; p < 0.01). In the study group, SNR improvement was seen in the right coronary artery (17.5 vs 13; p = 0.028), the left main (15.3 vs 12.3; p = 0.027), and the left anterior descending artery (18.5 vs 14.1; p = 0.048). Subjective image quality was rated higher in the study group (4.75 ± 0.7 vs 3.64 ± 0.5; p < 0.001). CONCLUSIONS The prototype test bolus evaluation algorithm provided a reliable patient-specific scan delay for CCTA that ensured homogenous vascular attenuation, improvement in objective and subjective image quality, and avoidance of beam hardening artifacts. ADVANCES IN KNOWLEDGE The prototype contrast bolus evaluation and optimization tool estimated circulation time-based time-delay improves the overall quality of CCTA.
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Affiliation(s)
- Andreas M Fischer
- Division of Cardiovascular Imaging, Department of Radiology and
Radiological Science, Medical University of South
Carolina, Charleston, South Carolina,
USA
- University Department of Geriatric Medicine FELIX PLATTER and
University of Basel, Basel,
Switzerland
| | - Josua A. Decker
- Division of Cardiovascular Imaging, Department of Radiology and
Radiological Science, Medical University of South
Carolina, Charleston, South Carolina,
USA
- Department of Diagnostic and Interventional Radiology,
University Hospital Augsburg,
Augsburg, Germany
| | - Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and
Radiological Science, Medical University of South
Carolina, Charleston, South Carolina,
USA
| | - Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and
Radiological Science, Medical University of South
Carolina, Charleston, South Carolina,
USA
| | | | | | | | | | - Dante A Giovagnoli
- Division of Cardiovascular Imaging, Department of Radiology and
Radiological Science, Medical University of South
Carolina, Charleston, South Carolina,
USA
| | - Tilman Emrich
- Division of Cardiovascular Imaging, Department of Radiology and
Radiological Science, Medical University of South
Carolina, Charleston, South Carolina,
USA
- Department of Diagnostic and Interventional Radiology,
University Medical Center, Mainz,
Germany
- German Center for Cardiovascular Research (DZHK), Partner Site
Rhine Main, Mainz,
Germany
| | - John D Martinez
- Division of Cardiovascular Imaging, Department of Radiology and
Radiological Science, Medical University of South
Carolina, Charleston, South Carolina,
USA
| | - Kia B Lari
- University of South Carolina School of Medicine
Greenville, Greenville, South
Carolina, USA
| | - Robert R Bayer
- Division of Cardiovascular Imaging, Department of Radiology and
Radiological Science, Medical University of South
Carolina, Charleston, South Carolina,
USA
- Division of Cardiology, Department of Medicine, Medical
University of South Carolina, Charleston, South
Carolina, USA
| | - Simon S Martin
- Division of Cardiovascular Imaging, Department of Radiology and
Radiological Science, Medical University of South
Carolina, Charleston, South Carolina,
USA
- Department of Diagnostic and Interventional Radiology,
University Hospital Frankfurt,
Frankfurt, Germany
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18
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Wang Q, Fu Q, Pang C. A NEW METHOD FOR ESTIMATING INCREASE IN RADIATION DOSE ASSOCIATED WITH IODINATED CONTRAST USE. RADIATION PROTECTION DOSIMETRY 2022; 198:281-289. [PMID: 35368083 DOI: 10.1093/rpd/ncac026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 01/25/2022] [Accepted: 02/02/2022] [Indexed: 06/14/2023]
Abstract
This work investigates the impact of iodinated contrast medium (ICM) on radiation dose in computed tomography (CT) scans using linear models established through a phantom study. Thermoluminescence dosemeters (TLDs) were calibrated using semi-conductor X-ray dosemeters. An electron density phantom, with a vial containing TLDs and different concentrations of iodinated blood, were scanned at different tube voltages. Irradiated TLD outputs were measured and absorbed dose to iodinated blood calculated. CT numbers (tissue attenuation as measured by Hounsfield units) were plotted against absorbed doses to obtain linear models. Data from 49 real patient scans were used to validate the linear models. At each X-ray energy, CT numbers were linearly correlated with the absorbed doses, that is with the increase of blood iodine concentration, the CT number increased and the absorbed dose increased accordingly. ICM can cause an increase of organ dose; the average dose increases were 31.8 ± 8.9% for thyroid, 37.1 ± 9.2% for cardiac muscle, 77.7 ± 14.0% for cardiac chamber, 7.1 ± 2.3% for breast, 26.1 ± 7.3% for liver, 39.8 ± 11.8% for spleen, 96.3 ± 12.2% for renal cortex and 82.4 ± 11.6% for medulla nephrica. ICM used in enhanced CT scan resulted in increased organ doses. Our models for estimating organ dose based on CT number were established by experiment and verified in clinical use.
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Affiliation(s)
- Qiang Wang
- Department of Occupational Disease Prevention, Changzhou Center for Disease Control and Prevention, Changzhou, Jiangsu 213022, China
| | - Qiang Fu
- Department of Occupational Disease Prevention, Changzhou Center for Disease Control and Prevention, Changzhou, Jiangsu 213022, China
| | - Cong Pang
- The First People's Hospital of Changzhou, Changzhou, Jiangsu 213022, China
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Yoshida M, Nakaura T, Oda S, Kidoh M, Nagayama Y, Uetani H, Azuma M, Sakabe D, Hirai T, Funama Y. Effects of tube voltage and iodine contrast medium on radiation dose of whole-body CT. Acta Radiol 2022; 63:458-466. [PMID: 33709794 DOI: 10.1177/02841851211001539] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The low-tube-voltage scan generally needs a higher tube current than the conventional 120 kVp to maintain the image noise. In addition, the low-tube-voltage scan increases the photoelectric effect, which increases the radiation absorption in organs. PURPOSE To compare the organ radiation dose caused by iodine contrast medium between low tube voltage with low contrast medium and that of conventional 120-kVp protocol with standard contrast medium. MATERIAL AND METHODS After the propensity-matching analysis, 66 patients were enrolled including 33 patients with 120 kVp and 600 mgI/kg and 33 patients with 80 kVp and 300 mgI/kg (50% iodine reduction). The pre- and post-contrast phases were assessed in all patients. The Monte Carlo simulation tool was used to simulate the radiation dose. The computed tomography (CT) numbers for 10 organs and the organ doses were measured. The organ doses were normalized by the volume CT dose index, and the 120-kVp protocol was compared with the 80-kVp protocol. RESULTS On contrast-enhanced CT, there were no significant differences in the mean CT numbers of the organs between 80-kVp and 120-kVp protocols except for the pancreas, kidneys, and small intestine. The normalized organ doses at 80 kVp were significantly lower than those of 120 kVp in all organs (e.g. liver, 1.6 vs. 1.9; pancreas, 1.5 vs. 1.8; spleen, 1.7 vs. 2.0) on contrast-enhanced CT. CONCLUSION The low tube voltage with low-contrast-medium protocol significantly reduces organ doses at the same volume CT dose index setting compared with conventional 120-kVp protocol with standard contrast medium on contrast-enhanced CT.
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Affiliation(s)
| | | | - Seitaro Oda
- Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Masafumi Kidoh
- Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | | | - Hiroyuki Uetani
- Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - M Azuma
- Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Daisuke Sakabe
- Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
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Sookpeng S, Martin CJ. A PHANTOM EVALUATION OF THE USE OF CT AUTOMATIC TUBE CURRENT MODULATION WITH LOW TUBE POTENTIALS FOR IODINATED CONTRAST STUDIES. RADIATION PROTECTION DOSIMETRY 2022; 198:188-195. [PMID: 35224645 DOI: 10.1093/rpd/ncac023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 10/29/2021] [Accepted: 02/08/2022] [Indexed: 06/14/2023]
Abstract
This paper aimed to investigate effects of different tube voltage and image quality settings on radiation dose and image quality for patients undergoing computed tomography iodinated contrast studies using automatic tube current modulation system and to recommend settings to achieve improved radiation dose and image quality values. A Pagoda phantom with an additional rod of iodine contrast was scanned using different tube voltages and noise index (NI) settings. Size-specific dose estimate (SSDE) and image quality (noise, contrast, contrast-to-noise ratio (CNR) and figure of merit (FOM)) were analysed. Values of SSDE were maintained with similar NI settings. Contrast and CNR were higher for lower tube voltage settings. Better FOM values can be achieved with higher NI settings with the lower kVs. To achieve better CNR and SSDE compared with the standard setting of 120 kV, a 80 kV with an NI setting of 15 was recommended.
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Affiliation(s)
- Supawitoo Sookpeng
- Department of Radiological Technology, Faculty of Allied Health Sciences, Naresuan University, Phitsanulok 65000, Thailand
| | - Colin J Martin
- Department of Clinical Physics and Bioengineering, University of Glasgow, Gartnavel Royal Hospital, Glasgow G12 0XH, UK
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Hoshika M, Nakaura T, Oda S, Kidoh M, Nagayama Y, Sakabe D, Hirai T, Funama Y. Comparison of the effects of varying tube voltage and iodinated concentration on increasing the iodinated radiation dose in computed tomography. Phys Med 2022; 95:57-63. [DOI: 10.1016/j.ejmp.2022.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 12/09/2021] [Accepted: 01/20/2022] [Indexed: 11/16/2022] Open
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22
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OUP accepted manuscript. Eur Heart J Cardiovasc Imaging 2022; 23:e279-e289. [DOI: 10.1093/ehjci/jeac048] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 03/02/2022] [Indexed: 11/14/2022] Open
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Dalah EZ, Obaideen A, Anam S, Khalid M, Nadishani T, Hashim S, Ghoshal SK. Cumulative lifetime attributed risks for patients subjected to contrast enhanced chest CT examinations. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2021.109710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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24
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Van Cauteren T, Tanaka K, Belsack D, Van Gompel G, Kersemans V, Jochmans K, Droogmans S, de Mey J, Buls N. Potential increase in radiation-induced DNA double-strand breaks with higher doses of iodine contrast during coronary CT angiography. Med Phys 2021; 48:7526-7533. [PMID: 34564862 PMCID: PMC9293077 DOI: 10.1002/mp.15253] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 06/25/2021] [Accepted: 09/14/2021] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To investigate the contrast media iodine dose dependency of radiation-induced DNA double-strand breaks (DSBs) during a coronary computed tomography angiography (CCTA) scan. METHODS This prospective patient study was approved by the ethical committee. Between November 2018 and July 2019, 50 patients (31 males and 19 females, mean age 64 years) were included in the study, 45 CCTA and five noncontrast-enhanced (NCE) cardiac computed tomography (CT) patients. A single-heartbeat scan protocol with a patient-tailored contrast media injection protocol was used, administering a patient-specific iodine dose. DNA double-strand breaks were quantified using a γH2AX foci assay on peripheral blood lymphocytes. The net amount of γH2AX/cell was normalized to the individual patient CT dose by the size-specific dose estimate (SSDE). Correlation between the administered and blood-iodine dose and the SSDE normalized amount of DNA DSBs was investigated using a Pearson correlation test. RESULTS CCTA patients were scanned with a mean CTDIvol of 10.6 ± 5.6 mGy, corresponding to a mean SSDE of 11.3 ± 5.3 mGy while the NCE cardiac CT patients were scanned with a mean CTDIvol of 6.00 ± 1.8 mGy, corresponding to a mean SSDE of 6.6 ± 2.7 mGy. The administered iodine dose ranged from 16.5 to 34.0 gI in the CCTA patients, resulting in a blood-iodine dose range from 5.1 to 15.0 gI in the exposed blood volume. A significant linear relationship (r = 0.79, p-value < 0.001) was observed between the blood iodine dose and SSDE normalized radiation-induced DNA DSBs. A similar significant linear relationship (r = 0.62, p-value < 0.001) was observed between the administered iodine dose and SSDE normalized radiation-induced DNA DSBs. CONCLUSIONS This study shows that contrast media iodine dose increases the level of radiation-induced DNA DSBs in peripheral blood lymphocytes in a linear dose-dependent manner with CCTA. Importantly, the level of DNA DSBs can be reduced by lowering the administered iodine dose.
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Affiliation(s)
- Toon Van Cauteren
- Department of RadiologyVrije Universiteit Brussel (VUB)Universitair Ziekenhuis Brussels (UZB)BrusselsBelgium
| | - Kaoru Tanaka
- Department of RadiologyVrije Universiteit Brussel (VUB)Universitair Ziekenhuis Brussels (UZB)BrusselsBelgium
| | - Dries Belsack
- Department of RadiologyVrije Universiteit Brussel (VUB)Universitair Ziekenhuis Brussels (UZB)BrusselsBelgium
| | - Gert Van Gompel
- Department of RadiologyVrije Universiteit Brussel (VUB)Universitair Ziekenhuis Brussels (UZB)BrusselsBelgium
| | - Veerle Kersemans
- Department of OncologyCRUK/MRC Institute for Radiation OncologyUniversity of OxfordOxfordUK
| | - Kristin Jochmans
- Department of HematologyVrije Universiteit Brussel (VUB)Universitair Ziekenhuis Brussels (UZB)BrusselsBelgium
| | - Steven Droogmans
- Department of CardiologyVrije Universiteit Brussel (VUB)Universitair Ziekenhuis Brussels (UZB)BrusselsBelgium
| | - Johan de Mey
- Department of RadiologyVrije Universiteit Brussel (VUB)Universitair Ziekenhuis Brussels (UZB)BrusselsBelgium
| | - Nico Buls
- Department of RadiologyVrije Universiteit Brussel (VUB)Universitair Ziekenhuis Brussels (UZB)BrusselsBelgium
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Nautiyal A, Mondal T, Manii M, Kaushik A, Goel A, Dey SK, Mitra D. Significant reduction of radiation dose and DNA damage in 18F- FDG whole-body PET/CT study without compromising diagnostic image quality. JOURNAL OF RADIATION RESEARCH AND APPLIED SCIENCES 2021. [DOI: 10.1080/16878507.2021.1969197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Amit Nautiyal
- Institute of Nuclear Medicine & Molecular Imaging, Amri Hospitals, Dhakuria, Kolkata
- Amity Institute of Nuclear Science & Technology, Amity University Uttar Pradesh, Noida
| | - Tanmoy Mondal
- Department of Biotechnology, Maulana Abul Kalam Azad University of Technology, Salt Lake, Kolkata
| | - Manu Manii
- Department of Nuclear Medicine, Quadra Medical Services Private Limited, Kolkata
| | - Aruna Kaushik
- Institute of Nuclear Medicine & Allied Sciences, Timarpur, Delhi
| | - Alpana Goel
- Amity Institute of Nuclear Science & Technology, Amity University Uttar Pradesh, Noida
| | - Subrata Kumar Dey
- Department of Biotechnology, Maulana Abul Kalam Azad University of Technology, Salt Lake, Kolkata
| | - Deepanjan Mitra
- Institute of Nuclear Medicine & Molecular Imaging, Amri Hospitals, Dhakuria, Kolkata
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Li G, Dong J, Cao Z, Wang J, Cao D, Zhang X, Zhang L, Lu G. Application of low-dose CT to the creation of 3D-printed kidney and perinephric tissue models for laparoscopic nephrectomy. Cancer Med 2021; 10:3077-3084. [PMID: 33797861 PMCID: PMC8085913 DOI: 10.1002/cam4.3851] [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: 01/12/2021] [Revised: 02/25/2021] [Accepted: 02/26/2021] [Indexed: 12/13/2022] Open
Abstract
PURPOSE The aim of this study was to explore the feasibility of 3D printing of kidney and perinephric fat based on low-dose CT technology. PATIENTS AND METHODS A total of 184 patients with stage T1 complex renal tumors who underwent laparoscopic nephrectomy were prospectively enrolled and divided into three groups: group A (conventional dose kidney and perinephric fat 3D printing group, n = 62), group B (low-dose kidney and perinephric fat 3D printing, n = 64), and group C (conventional dose merely kidney 3D printing group, n = 58). The effective dose (ED), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were determined. The 3D printing quality was evaluated using a 4-point scale, and interobserver agreement was assessed using the intraclass correlation coefficient (ICC). RESULTS The ED of group B was lower than that of group A, with a decrease of 55.1%. The subjective scores of 3D printing quality in all groups were 3 or 4 points. The interobserver agreement among the three observers in 3D printing quality was good (ICC = 0.84-0.92). The perioperative indexes showed that operation time (OT), warm ischemia time (WIT), estimated blood loss (EBL), and laparoscopic partial nephrectomy (LPN) conversion to laparoscopic radical nephrectomy (LRN) in groups A or B were significantly less than those in group C. LPN was more frequent in group A and group B than in group C (all p < 0.017). There were no significant differences in perioperative indexes between group A and group B (all p > 0.017). CONCLUSION Low-dose CT technology can be effectively applied to 3D printing of kidney and perinephric fat and reduce the patient's radiation dose without compromising 3D printing quality. 3D printing of kidney and perinephric fat can significantly increase the success rate of LPN and decrease OT, WIT, and EBL.
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Affiliation(s)
- Guan Li
- Department of Radiology, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Jie Dong
- Department of Urology, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Zhiqiang Cao
- Department of Urology, General Hospital of Northern Theater Command, Shenyang, China
| | - Jinbao Wang
- Department of Radiology, General Hospital of Northern Theater Command, Shenyang, China
| | - Dongbing Cao
- Department of Urology, Cancer Hospital of China Medical University, Shenyang, China
| | - Xin Zhang
- Department of Radiology, The First Affiliated Hospital of China Medical University, Shenyang, China
| | - Longjiang Zhang
- Department of Radiology, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Guangming Lu
- Department of Radiology, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
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Double Low-Dose Dual-Energy Liver CT in Patients at High-Risk of HCC: A Prospective, Randomized, Single-Center Study. Invest Radiol 2021; 55:340-348. [PMID: 31917765 DOI: 10.1097/rli.0000000000000643] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVES The aim of this study was to investigate the clinical feasibility of the simultaneous reduction of radiation and contrast doses using spectral computed tomography (CT) in patients at high-risk for hepatocellular carcinoma. MATERIALS AND METHODS Between May 2017 and March 2018, this prospective study recruited participants at risk of hepatocellular carcinoma with body mass indexes less than 30 and randomly assigned them to either the standard-dose group or the double low-dose group, which targeted 30% reductions in both radiation and contrast media (NCT03045445). Lesion conspicuity as a primary endpoint and lesion detection rates were then compared between hybrid iterative reconstruction (iDose) images of standard-dose group and low monoenergetic (50 keV) images of double low-dose group. Qualitative and quantitative image noise and contrast were also compared between the 2 groups. Participants and reviewers were blinded for scan protocols and reconstruction algorithms. Lesion conspicuity was analyzed using generalized estimating equation analysis. Lesion detection was evaluated using weighted jackknife alternative free-response receiver operating characteristic analysis. RESULTS Sixty-seven participants (male-to-female ratio, 59:8; mean age, 64 ± 9 years) were analyzed. Compared with the standard-dose group (n = 32), significantly lower CTDIvol (8.8 ± 1.7 mGy vs 6.1 ± 0.6 mGy) and contrast media (116.9 ± 15.7 mL vs 83.1 ± 9.9 mL) were utilized in the double low-dose group (n = 35; P < 0.001). Comparative analysis demonstrated that lesion conspicuity was significantly higher on 50 keV images of double low-dose group than on iDose images of standard dose on both arterial (2.62 [95% confidence interval (CI), 2.31-2.93] vs 2.02 [95% CI, 1.73-2.30], respectively, P = 0.004) and portal venous phases (2.39 [95% CI, 2.11-2.67] vs 1.88 [95% CI, 1.67-2.10], respectively, P = 0.005). No differences in lesion detection capability were observed between the 2 groups (figure of merit: 0.63 in standard-dose group; 0.65, double low-dose group; P = 0.52). Fifty kiloelectronvolt images of double low-dose group showed better subjective image noise and contrast than iDose image of standard-dose group on arterial and portal venous phases (P < 0.001 for all). Contrast-to-noise ratio of the aorta and portal vein was also higher in double low-dose group than in standard-dose group (P < 0.001 for all), whereas there was no significant difference of quantitative image noise between the 2 groups on arterial and portal phases (P = 0.4~0.5). CONCLUSIONS Low monoenergetic spectral CT images (50 keV) can provide better focal liver lesion conspicuity than hybrid iterative reconstruction image of standard-dose CT in nonobese patients while using lower radiation and contrast media doses.
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The presence of contrast agent increases organ radiation dose in contrast-enhanced CT. Eur Radiol 2021; 31:7540-7549. [PMID: 33783569 PMCID: PMC8452580 DOI: 10.1007/s00330-021-07763-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 01/08/2021] [Accepted: 02/05/2021] [Indexed: 01/09/2023]
Abstract
Objectives Routine dosimetry calculations do not account for the presence of iodine in organs and tissues during CT acquisition. This study aims to investigate the impact of contrast agent (CA) on radiation dose. Methods First, relation between absorbed radiation dose and iodine concentrations was investigated using a cylindrical water phantom with iodine-saline dilution insertions. Subsequently, a retrospective study on abdominal dual-energy CT (DECT) patient data was performed to assess the increase of the local absorbed radiation dose compared to a non-contrast scan. Absorbed doses were estimated with Monte Carlo simulations using the individual CT voxel data of phantom and patients. Further, organ segmentations were performed to obtain the dose in liver, liver parenchyma, left kidney, right kidney, aorta, and spleen. Results In the phantom study, a linear relation was observed between the radiation dose normalized by computed tomography dose index (CTDI) and CA concentrations Iconc (mg/ml) for three tube voltages; \documentclass[12pt]{minimal}
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\begin{document}$$ \frac{D_{80 kVp}}{CTDI_{vol}} $$\end{document}D80kVpCTDIvol = 0.14 × Iconc + 1.02, \documentclass[12pt]{minimal}
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\begin{document}$$ \frac{D_{120 kVp}}{CTDI_{vol}} $$\end{document}D120kVpCTDIvol = 0.16 × Iconc + 1.21, \documentclass[12pt]{minimal}
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\begin{document}$$ \frac{D_{140 kVp}}{CTDI_{vol}} $$\end{document}D140kVpCTDIvol = 0.16 × Iconc + 1.24, and for DECT acquisition; \documentclass[12pt]{minimal}
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\begin{document}$$ \frac{D_{DECT}}{CTDI_{vol}} $$\end{document}DDECTCTDIvol = 0.15 × Iconc + 1.09. Similarly, a linear relation was observed between the dose increase and the organ iodine contents (R2 = 0.86 and pvalue < 0.01) in the patient study. The relative doses increased in the liver (21 ± 5%), liver parenchyma (20 ± 5%), right kidney (37 ± 7%), left kidney (39 ± 7%), aorta (34 ± 6%) and spleen (26 ± 4%). In addition, the local dose distributions changed based on patient’s anatomy and physiology. Conclusions Compared to a non-contrast scan, the organ doses increase by 30% in contrast-enhanced abdominal CT. This study suggests considering CA in dosimetry calculations, epidemiological studies, and organ dose estimations while developing new CT protocols. Key Points • The presence of contrast media increases radiation absorption in CT, and this increase is related to the iodine content in the organs. • The increased radiation absorption due to contrast media can lead to an average 30% increase in absorbed organ dose. • Iodine should be considered in CT radiation safety studies.
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Zawam Dalah E, Dhou S, Mudalige T, Amin F, Obaideen A. Challenges estimating patient organs doses undergoing enhanced chest CT examination: exploratory study. Biomed Phys Eng Express 2021; 7. [PMID: 33588398 DOI: 10.1088/2057-1976/abe68e] [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: 11/23/2020] [Accepted: 02/15/2021] [Indexed: 11/11/2022]
Abstract
Purpose: Estimate organs doses (ODs) of patients subjected to unenhanced (S1) and enhanced (S2) chest CT studies relying on image parameters such as Hounsfield Units (HUs).Materials and Methods: CT scans and images of a total of 16 patients who underwent two series of chest CT studies were obtained and retrospectively examined. OD increments of liver and pancreas for both series (S1 & S2) were estimated using two different independent methods, namely simulation approach using CT-EXPO and Amato's phantom-based fitting model (APFM). HUs were quantified for each organ by manually drawing fixed area-sized regions of interest (ROIs). The mean HUs were collected to obtain the ODs increments following APFM. Regression analysis was applied to find and assess the relationship between the HUs and the OD increments estimated using APFM and that using CT-EXPO. Spearman Coefficient and Wilcoxon Matched Pairedt-testwere conducted to show statistical correlation and difference between ODs increments using the two methods.Results:A strong significant difference was depicted between S1 and S2 scan series of liver and pancreas using CT-EXPO simulation. Mean HU values for S1 were lower than S2, resulting in statistically significant (p < 0.0001) HU changes. CT-EXPO simulation yielded significantly higher difference in ODs compared to the APFM for liver (p = 0.0455) and pancreas (p = 0.0031). Regression analysis revealed a strong relationship between HU of S1 and S2 and ODs increments using APFM in both organs (R2 = 0.99), dissimilar to CT-EXPO (R2 = 0.39 in liver andR2 = 0.05 in pancreas).Conclusions: Although CT-EXPO allows for estimating ODs accounting for major acquisition scan parameters, it is not a reliable tool to evaluate the impact of contrast enhancement on ODs. On the other hand, the APFM accounts for contrast enhancement accumulation yet only provides relative OD increments, an information of limited clinical use.
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Affiliation(s)
- Entesar Zawam Dalah
- Department of Clinical Support Services and Nursing Sector, Dubai Health Authority, Dubai, UAE.,Department of Medical Diagnostic Imaging, University of Sharjah, Sharjah, UAE
| | - Salam Dhou
- Department of Computer Science and Engineering, American University of Sharjah, Sharjah, UAE
| | - Thilini Mudalige
- Department of Medical Diagnostic Imaging, University of Sharjah, Sharjah, UAE
| | - Fatima Amin
- Department of Medical Diagnostic Imaging, University of Sharjah, Sharjah, UAE
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Kamal R, Thaper D, Kumar R, Singh G, Yadav HP, Oinam AS, Kumar V, Sharma H. Dosimetric impact of contrast-enhanced 4d computed tomography for stereotactic body radiation therapy of hepatocelluar carcinoma. Rep Pract Oncol Radiother 2021; 26:598-604. [PMID: 34434576 PMCID: PMC8382070 DOI: 10.5603/rpor.a2021.0075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 02/27/2021] [Indexed: 05/08/2023] Open
Abstract
BACKGROUND A purpose of the study was to investigate the dosimetric impact of contrast media on dose calculation using average 4D contrast-enhanced computed tomography (4D-CECT) and delayed 4D-CT (d4D-CT) images caused by CT simulation contrast agents for stereotactic body radiation therapy (SBRT) of liver cases. MATERIALS AND METHODS Fifteen patients of liver SBRT treated using the volumetric modulated arc therapy (VMAT) technique were selected retrospectively. 4D-CECT, and d4D-CT were acquired with the Anzai gating system and GE CT. For all patients, gross target volume (GTV) was contoured on the ten phases after rigid registration of both the contrast and delayed scans and merged to generate internal target volume (ITV) on average CT images. Region of interest (ROI) was drawn on contrast images and then copied to the delayed images after rigid registration of two average CT datasets. The treatment plans were generated for contrast enhanced average CT, delayed average CT and contrast enhanced average CT with electron density of the heart overridden. RESULTS No significant dosimetric difference was observed in plans parameters (mean HU value of the liver, total monitor units, total control points, degree of modulation and average segment area) except mean HU value of the aorta amongst the three arms. All the OARs were evaluated and resulted in statistically insignificant variation (p > 0.05) using one way ANOVA analysis. CONCLUSIONS Contrast enhanced 4D-CT is advantageous in accurate delineation of tumors and assessing accurate ITV. The treatment plans generated on average 4D-CECT and average d4D-CT have a clinically insignificant effect on dosimetric parameters.
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Affiliation(s)
- Rose Kamal
- Centre for Medical Physics, Panjab University, Chandigarh, India
- Department of Radiation Oncology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Deepak Thaper
- Centre for Medical Physics, Panjab University, Chandigarh, India
- Department of Radiation Oncology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Rishabh Kumar
- Centre for Medical Physics, Panjab University, Chandigarh, India
| | - Gaganpreet Singh
- Centre for Medical Physics, Panjab University, Chandigarh, India
- Department of Radiotherapy, Post Graduate Institute of Medical Education and Research, Regional Cancer Centre, Chandigarh, India
| | - Hanuman P. Yadav
- Department of Radiation Oncology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Arun S. Oinam
- Department of Radiotherapy, Post Graduate Institute of Medical Education and Research, Regional Cancer Centre, Chandigarh, India
| | - Vivek Kumar
- Centre for Medical Physics, Panjab University, Chandigarh, India
| | - Hitesh Sharma
- Govt. Cancer Hospital, NSCB Medical College, Jabalpur, Madhya Pradesh, India
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Sakabe D, Nakaura T, Oda S, Kidoh M, Utsunomiya D, Masahiro Hatemura RT, Funama Y. Decreasing the radiation dose for contrast-enhanced abdominal spectral CT with a half contrast dose: a matched-pair comparison with a 120 kVp protocol. BJR Open 2020; 2:20200006. [PMID: 33367197 PMCID: PMC7749088 DOI: 10.1259/bjro.20200006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 09/18/2020] [Indexed: 12/15/2022] Open
Abstract
Objectives To compare the estimated radiation dose of 50% reduced iodine contrast medium (halfCM) for virtual monochromatic images (VMIs) with that of standard CM (stdCM) with a 120 kVp imaging protocol for contrast-enhanced CT (CECT). Methods We enrolled 30 adults with renal dysfunction who underwent abdominal CT with halfCM for spectral CT. As controls, 30 matched patients without renal dysfunction using stdCM were also enrolled. CT images were reconstructed with the VMIs at 55 keV with halfCM and 120 kVp images with stdCM and halfCM. The Monte-Carlo simulation tool was used to simulate the radiation dose. The organ doses were normalized to CTDIvol for the liver, pancreas, spleen, and kidneys and measured between halfCM and stdCM protocols. Results For the arterial phase, the mean organ doses normalized to CTDIvol for stdCM and halfCM were 1.22 and 1.29 for the liver, 1.50 and 1.35 for the spleen, 1.75 and 1.51 for the pancreas, and 1.89 and 1.53 for the kidneys. As compared with non-enhanced CT, the average increase in the organ dose was significantly lower for halfCM (13.8% ± 14.3 and 26.7% ± 16.7) than for stdCM (31.0% ± 14.3 and 38.5% ± 14.8) during the hepatic arterial and portal venous phases (p < 0.01). Conclusion As compared with stdCM with the 120 kVp imaging protocol, a 50% reduction in CM with VMIs with the 55 keV protocol allowed for a substantial reduction of the average organ dose of iodine CM while maintaining the iodine CT number for CECT. Advances in knowledge This study provides that the halfCM protocol for abdominal CT with a dual-layer-dual-energy CT can significantly reduce the increase in the average organ dose for non-enhanced CT as compared with the standard CM protocol.
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Affiliation(s)
| | - Takeshi Nakaura
- Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Seitaro Oda
- Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Masafumi Kidoh
- Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Daisuke Utsunomiya
- Diagnostic Radiology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | | | - Yoshinori Funama
- Department of Medical Physics, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
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Karami H, Miri-Hakimabad H, Hoseinian-Azghadi E. The effect of contrast material on radiation dose during computed tomography pulmonary angiography. Z Med Phys 2020; 30:211-221. [PMID: 32540162 DOI: 10.1016/j.zemedi.2020.03.003] [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: 10/26/2019] [Revised: 03/26/2020] [Accepted: 03/30/2020] [Indexed: 11/20/2022]
Abstract
This study evaluated the impact of contrast material (CM) on radiation dose for adults undergoing computed tomography pulmonary angiography (CTPA). A previously developed physiologically based pharmacokinetic (PBPK) model and phantoms representing the average (reference) adult male and female individual were used to evaluate the iodine concentration in tissues as a function of time elapsed since the initiation of iodinated contrast medium administration. In order to estimate the radiation dose more accurately, a detailed model of pulmonary vessels was added to the phantoms. Then, the material composition of phantoms was modified to include the iodine concentration in different organs and tissues at different acquisition times after CM injection. The calculations were performed using Monte Carlo N-Particle extended code (MCNPX) version 2.6.0. The radiation dose estimates during CTPA were provided as a function of scan acquisition time after injection considering the distribution of iodinated CM within ICRP reference phantoms. It was shown that the estimated radiation dose to the lungs could be 31-40% (27-34%) larger when considering the effect of iodinated contrast administration with injection rate of 5 (3)mL/s. Moreover, the effective dose for contrast-enhanced CT (CECT) would be utmost 10-13% larger than that for non-enhanced CT (NECT). The radiation doses to the other organs in-/outside the scanned region would be decreased if the scan performed on time. In case of late scanning, absorbed dose decreases slightly for lungs (∼15-20%) whereas becomes (∼10% or more) higher than its NECT value for some organs such as heart muscle, kidneys, and spleen. To sum up, the late scanning (Δt>5s after the end of injection) is not recommended because of higher dose delivered to other organs than the lungs (particularly heart muscle).
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Affiliation(s)
- Haleh Karami
- Physics Department, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Hashem Miri-Hakimabad
- Physics Department, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran.
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Samei E, Ria F, Tian X, Segars PW. A database of 40 patient-based computational models for benchmarking organ dose estimates in CT. Med Phys 2020; 47:6562-6566. [PMID: 32628272 DOI: 10.1002/mp.14373] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 05/24/2020] [Accepted: 06/26/2020] [Indexed: 11/12/2022] Open
Abstract
PURPOSE Patient radiation burden in computed tomography (CT) can best be characterized through risk estimates derived from organ doses. Organ doses can be estimated by Monte Carlo simulations of the CT procedures on computational phantoms assumed to emulate the patients. However, the results are subject to uncertainties related to how accurately the patient and CT procedure are modeled. Different methods can lead to different results. This paper, based on decades of organ dosimetry research, offers a database of CT scans, scan specifics, and organ doses computed using a validated Monte Carlo simulation of each patient and acquisition. It is aimed that the database can serve as means to benchmark different organ dose estimation methods against a benchmark dataset. ACQUISITION AND VALIDATION METHODS Organ doses were estimated for 40 adult patients (22 male, 18 female) who underwent chest and abdominopelvic CT examinations. Patient-based computational models were created for each patient including 26 organs for female and 25 organs for male cases. A Monte Carlo code, previously validated experimentally, was applied to calculate organ doses under constant and two modulated tube current conditions. DATA FORMAT AND USAGE NOTES The generated database reports organ dose values for chest and abdominopelvic examinations per patient and imaging condition. Patient information and images and scan specifications (energy spectrum, bowtie filter specification, and tube current profiles) are provided. The database is available at publicly accessible digital repositories. POTENTIAL APPLICATIONS Consistency in patient risk estimation, and associated justification and optimization requires accuracy and consistency in organ dose estimation. The database provided in this paper is a helpful tool to benchmark different organ dose estimation methodologies to facilitate comparisons, assess uncertainties, and improve risk assessment of CT scans based on organ dose.
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Affiliation(s)
- Ehsan Samei
- Carl E. Ravin Advanced Imaging Labs, Clinical Imaging Physics Group, Medical Physics Graduate Program, Departments of Radiology, Physics, Biomedical Engineering, and Electrical and Computer Engineering, Duke University, 2424 Erwin Road, Suite 302, Durham, NC, 27710, USA
| | - Francesco Ria
- Carl E. Ravin Advanced Imaging Labs and Clinical Imaging Physics Group, Duke University Health System, 2424 Erwin Road, Suite 302, Durham, NC, 27710, USA
| | - Xiaoyu Tian
- Carl E. Ravin Advanced Imaging Labs, 2424 Erwin Road, Suite 302, Durham, NC, 27710, USA
| | - Paul W Segars
- Carl E. Ravin Advanced Imaging Labs, 2424 Erwin Road, Suite 302, Durham, NC, 27710, USA
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Abadi E, Segars WP, Tsui BMW, Kinahan PE, Bottenus N, Frangi AF, Maidment A, Lo J, Samei E. Virtual clinical trials in medical imaging: a review. J Med Imaging (Bellingham) 2020; 7:042805. [PMID: 32313817 PMCID: PMC7148435 DOI: 10.1117/1.jmi.7.4.042805] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 03/23/2020] [Indexed: 12/13/2022] Open
Abstract
The accelerating complexity and variety of medical imaging devices and methods have outpaced the ability to evaluate and optimize their design and clinical use. This is a significant and increasing challenge for both scientific investigations and clinical applications. Evaluations would ideally be done using clinical imaging trials. These experiments, however, are often not practical due to ethical limitations, expense, time requirements, or lack of ground truth. Virtual clinical trials (VCTs) (also known as in silico imaging trials or virtual imaging trials) offer an alternative means to efficiently evaluate medical imaging technologies virtually. They do so by simulating the patients, imaging systems, and interpreters. The field of VCTs has been constantly advanced over the past decades in multiple areas. We summarize the major developments and current status of the field of VCTs in medical imaging. We review the core components of a VCT: computational phantoms, simulators of different imaging modalities, and interpretation models. We also highlight some of the applications of VCTs across various imaging modalities.
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Affiliation(s)
- Ehsan Abadi
- Duke University, Department of Radiology, Durham, North Carolina, United States
| | - William P. Segars
- Duke University, Department of Radiology, Durham, North Carolina, United States
| | - Benjamin M. W. Tsui
- Johns Hopkins University, Department of Radiology, Baltimore, Maryland, United States
| | - Paul E. Kinahan
- University of Washington, Department of Radiology, Seattle, Washington, United States
| | - Nick Bottenus
- Duke University, Department of Biomedical Engineering, Durham, North Carolina, United States
- University of Colorado Boulder, Department of Mechanical Engineering, Boulder, Colorado, United States
| | - Alejandro F. Frangi
- University of Leeds, School of Computing, Leeds, United Kingdom
- University of Leeds, School of Medicine, Leeds, United Kingdom
| | - Andrew Maidment
- University of Pennsylvania, Department of Radiology, Philadelphia, Pennsylvania, United States
| | - Joseph Lo
- Duke University, Department of Radiology, Durham, North Carolina, United States
| | - Ehsan Samei
- Duke University, Department of Radiology, Durham, North Carolina, United States
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Gao Y, Mahmood U, Liu T, Quinn B, Gollub MJ, Xu XG, Dauer LT. Patient-Specific Organ and Effective Dose Estimates in Adult Oncologic CT. AJR Am J Roentgenol 2020; 214:738-746. [PMID: 31414882 PMCID: PMC7393764 DOI: 10.2214/ajr.19.21197] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE. Patient-specific organ and effective dose provides essential information for CT protocol optimization. However, such information is not readily available in the scan records. The purpose of this study was to develop a method to obtain accurate examination- and patient-specific organ and effective dose estimates by use of available scan data and patient body size information for a large cohort of patients. MATERIALS AND METHODS. The data were randomly collected for 1200 patients who underwent CT in a 2-year period. Physical characteristics of the patients and CT technique were processed as inputs for the dose estimator. Organ and effective doses were estimated by use of the inputs and computational human phantoms matched to patients on the basis of sex and effective diameter. Size-based ratios were applied to correct for patient-phantom body size differences. RESULTS. Patients received a mean of 59.9 mGy to the lens of the eye per brain scan, 10.1 mGy to the thyroid per chest scan, 17.5 mGy to the liver per abdomen and pelvis scan, and 19.0 mGy to the liver per body scan. A factor of 2 difference in dose estimates was observed between patients of various habitus. CONCLUSION. Examination- and patient-specific organ and effective doses were estimated for 1200 adult oncology patients undergoing CT. The dose conversion factors calculated facilitate rapid organ and effective dose estimation in clinics. Compared with nonspecific dose estimation methods, patient dose estimations with data specific to the patient and examination can differ by a factor of 2.
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Affiliation(s)
- Yiming Gao
- Department of Medical Physics, Box 84, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Usman Mahmood
- Department of Medical Physics, Box 84, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Tianyu Liu
- Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Brian Quinn
- Department of Medical Physics, Box 84, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Marc J. Gollub
- Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - X. George Xu
- Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Lawrence T. Dauer
- Department of Medical Physics, Box 84, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
- Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
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Karout L, El Asmar K, Naffaa L, Abi-Ghanem AS, El-Merhi F, Salman R, Saade C. Balancing act between quantitative and qualitative image quality between nonionic iodinated dimer and monomer at various vessel sizes during computed tomography: a phantom study. Biomed Phys Eng Express 2020; 6:035001. [PMID: 33438646 DOI: 10.1088/2057-1976/ab78dc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE Investigate the impact of nonionic dimer and monomer on iodine quantification in different vessel sizes when employing a vascular specific phantom and varying iodinated contrast media (ICM) concentrations during computed tomography (CT). MATERIALS AND METHODS We created a vascular specific phantom (30 cm) to simulate human blood vessel diameters (25 cylinders of different diameters: 10 × 9mm, 10 × 12mm and 5 × 21mm). The phantom was filled with two ICM separately: Group: Iohexol(monomer)350 mg ml-1 and B: Iodixanol(Dimer)320 mg ml-1. Cylinders of same size were filled with increasing ICM concentration(10%-100%) while large cylinders were filled in quartiles(25%-100%). Phantom was scanned with different tube potential (80-140kVp), current (50-400mAs), reconstruction method [filtered back projection (FBP), hybrid-based iterative reconstruction (HBIR) and model-based iterative reconstruction (MBIR)] for each ICM. Chi-square was employed to compare mean opacification, contrast/noise ratio (CNR) and noise. Qualitative analysis was assessed by Visual grading characteristic (VGC) and Cohens-kappa analyses. RESULTS At 80 and140kVp significant difference in opacification between Group A (2054 ± 1040HU and 1696 ± 1027HU) and B (2169 ± 1105HU and 1568 ± 1034HU) was demonstrated (p < 0.001). However, at 100 and 120kVp no difference was noted (p > 0.05). When comparing image noise, it was higher in Group A compared to B (p < 0.05). CNR was higher in Group B (119.99 ± 126.10HU) than A (107.09 ± 102.56HU) (p < 0.0001). VGC: Group A outperformed B in image opacification in all vessel sizes and ICM concentrations except at medium vessels with concentration group 2(0.4-0.6 mg ml-1). Cohens'-kappa: agreement in opacification between each ICM group and iodine concentration 1(0-0.3 mg ml-1): κ = 0.253 and 0.014 respectively, concentration 2(0.4-0.6 mg ml-1):κ = -0.017 and -0.005 respectively and concentration 3(0.7-1 mg ml-1):κ = 0.031 and 0.115 respectively. CONCLUSION Nonionic dimer (Iodixanol) surpasses monomer (Iohexol) in quantitative image quality assessment by having lower image noise and higher CNR during CT.
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Affiliation(s)
- Lina Karout
- Diagnostic Radiology Department, American University of Beirut Medical Center, Beirut, American University of Beirut Medical Center, Beirut, Lebanon. P O Box: 11-0236 Riad El-Solh, Beirut, 1107 2020, Lebanon
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Honkanen MKM, Saukko AEA, Turunen MJ, Shaikh R, Prakash M, Lovric G, Joukainen A, Kröger H, Grinstaff MW, Töyräs J. Synchrotron MicroCT Reveals the Potential of the Dual Contrast Technique for Quantitative Assessment of Human Articular Cartilage Composition. J Orthop Res 2020; 38:563-573. [PMID: 31535728 PMCID: PMC7065106 DOI: 10.1002/jor.24479] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 09/13/2019] [Indexed: 02/04/2023]
Abstract
Dual contrast micro computed tomography (CT) shows potential for detecting articular cartilage degeneration. However, the performance of conventional CT systems is limited by beam hardening, low image resolution (full-body CT), and long acquisition times (conventional microCT). Therefore, to reveal the full potential of the dual contrast technique for imaging cartilage composition we employ the technique using synchrotron microCT. We hypothesize that the above-mentioned limitations are overcome with synchrotron microCT utilizing monochromatic X-ray beam and fast image acquisition. Human osteochondral samples (n = 41, four cadavers) were immersed in a contrast agent solution containing two agents (cationic CA4+ and non-ionic gadoteridol) and imaged with synchrotron microCT at an early diffusion time point (2 h) and at diffusion equilibrium (72 h) using two monochromatic X-ray energies (32 and 34 keV). The dual contrast technique enabled simultaneous determination of CA4+ (i.e., proteoglycan content) and gadoteridol (i.e., water content) partitions within cartilage. Cartilage proteoglycan content and biomechanical properties correlated significantly (0.327 < r < 0.736, p < 0.05) with CA4+ partition in superficial and middle zones at both diffusion time points. Normalization of the CA4+ partition with gadoteridol partition within the cartilage significantly (p < 0.05) improved the detection sensitivity for human osteoarthritic cartilage proteoglycan content, biomechanical properties, and overall condition (Mankin, Osteoarthritis Research Society International, and International Cartilage Repair Society grading systems). The dual energy technique combined with the dual contrast agent enables assessment of human articular cartilage proteoglycan content and biomechanical properties based on CA4+ partition determined using synchrotron microCT. Additionally, the dual contrast technique is not limited by the beam hardening artifact of conventional CT systems. © 2019 The Authors. Journal of Orthopaedic Research® published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 38:563-573, 2020.
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Affiliation(s)
- Miitu K. M. Honkanen
- Department of Applied PhysicsUniversity of Eastern FinlandKuopioFinland
- Diagnostic Imaging CenterKuopio University HospitalKuopioFinland
| | - Annina E. A. Saukko
- Department of Applied PhysicsUniversity of Eastern FinlandKuopioFinland
- Department of Medical PhysicsTurku University HospitalTurkuFinland
| | - Mikael J. Turunen
- Department of Applied PhysicsUniversity of Eastern FinlandKuopioFinland
- SIB LabsUniversity of Eastern FinlandKuopioFinland
| | - Rubina Shaikh
- Department of Applied PhysicsUniversity of Eastern FinlandKuopioFinland
| | - Mithilesh Prakash
- Department of Applied PhysicsUniversity of Eastern FinlandKuopioFinland
- Diagnostic Imaging CenterKuopio University HospitalKuopioFinland
- A.I. Virtanen Institute for Molecular SciencesUniversity of Eastern FinlandKuopioFinland
| | - Goran Lovric
- Centre d'lmagerie BioMédicaleÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland
- Swiss Light SourcePaul Scherrer InstituteVilligenSwitzerland
| | - Antti Joukainen
- Department of Orthopedics, Traumatology and Hand SurgeryKuopio University HospitalKuopioFinland
| | - Heikki Kröger
- Department of Orthopedics, Traumatology and Hand SurgeryKuopio University HospitalKuopioFinland
| | - Mark W. Grinstaff
- Departments of Biomedical Engineering, Chemistry, and MedicineBoston UniversityBostonMassachusetts
| | - Juha Töyräs
- Department of Applied PhysicsUniversity of Eastern FinlandKuopioFinland
- Diagnostic Imaging CenterKuopio University HospitalKuopioFinland
- School of Information Technology and Electrical EngineeringThe University of QueenslandBrisbaneQueenslandAustralia
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Shirasaka T, Nagao M, Yamasaki Y, Kojima T, Kondo M, Hamasaki H, Kamitani T, Kato T, Asayama Y. Low Radiation Dose and High Image Quality of 320-Row Coronary Computed Tomography Angiography Using a Small Dose of Contrast Medium and Refined Scan Timing Prediction. J Comput Assist Tomogr 2020; 44:7-12. [PMID: 31939875 DOI: 10.1097/rct.0000000000000951] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The aim of the study was to investigate the feasibility of coronary computed tomography (CT) angiography with a low kilovoltage peak scan and a refined scan timing prediction using a small contrast medium (CM) dose. METHODS In protocol A, 120-kVp scanning and a standard CM dose were used. The scan timing was fixed. In protocol B, 80 kVp and a 60% CM dose were used. The scan timing was determined according to the interval from the CM arrival to the peak time in the ascending aorta. We measured the CT number and recorded the radiation dose. RESULTS Higher CT numbers were observed in the left circumflex (proximal, P = 0.0235; middle, P = 0.0007; distal, P < 0.0001) in protocol B compared with protocol A. The radiation dose in protocol B was significantly lower than in protocol A (2.2 ± 0.9 vs 4.3 ± 1.7 mSv). CONCLUSIONS Low-contrast, low-radiation dose, high-image quality coronary CT angiography can be performed with low kilovoltage peak scanning and a refined scan timing prediction.
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Affiliation(s)
- Takashi Shirasaka
- From the Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Fukuoka Prefecture
| | - Michinobu Nagao
- Department of Diagnostic Imaging & Nuclear Medicine, Tokyo Women's Medical University, Shinjuku-ku, Tokyo
| | | | - Tsukasa Kojima
- From the Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Fukuoka Prefecture
| | - Masatoshi Kondo
- From the Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Fukuoka Prefecture
| | - Hiroshi Hamasaki
- From the Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Fukuoka Prefecture
| | | | - Toyoyuki Kato
- From the Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Fukuoka Prefecture
| | - Yoshiki Asayama
- Advanced Imaging and Interventional Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Fukuoka Prefecture, Japan
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Barat M, Paisant A, Calame P, Purcell Y, Lagadec M, Curac S, Zappa M, Vilgrain V, Ronot M. Unenhanced CT for clinical triage of elderly patients presenting to the emergency department with acute abdominal pain. Diagn Interv Imaging 2019; 100:709-719. [DOI: 10.1016/j.diii.2019.05.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 04/28/2019] [Accepted: 05/18/2019] [Indexed: 02/06/2023]
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40
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Iodine Dose of Administered Contrast Media Affects the Level of Radiation-Induced DNA Damage During Cardiac CT Scans. AJR Am J Roentgenol 2019; 213:404-409. [DOI: 10.2214/ajr.18.20950] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Tan SK, Ng KH, Yeong CH, Raja Aman RRA, Mohamed Sani F, Abdul Aziz YF, Sun Z. Personalized administration of contrast medium with high delivery rate in low tube voltage coronary computed tomography angiography. Quant Imaging Med Surg 2019; 9:552-564. [PMID: 31143647 DOI: 10.21037/qims.2019.03.13] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Background High delivery rate is an important factor in optimizing contrast medium administration in coronary computed tomography angiography (CCTA). A personalized contrast volume calculation algorithm incorporating high iodine delivery rate (IDR) can reduce total iodine dose (TID) and produce optimal vessel contrast enhancement (VCE) in low tube voltage CCTA. In this study, we developed and validated an algorithm for calculating the volume of contrast medium delivered at a high rate for patients undergoing retrospectively ECG-gated CCTA with low tube voltage protocol. Methods The algorithm for an IDR of 2.22 gI·s-1 was developed based on the relationship between VCE and contrast volume in 141 patients; test bolus parameters and characteristics in 75 patients; and, tube voltage in a phantom study. The algorithm was retrospectively tested in 45 patients who underwent retrospectively ECG-gated CCTA with a 100 kVp protocol. Image quality, TID and radiation dose exposure were compared with those produced using the 120 kVp and routine contrast protocols. Results Age, sex, body surface area (BSA) and peak contrast enhancement (PCE) were significant predictors for VCE (P<0.05). A strong linear correlation was observed between VCE and contrast volume (r=0.97, P<0.05). The 100-to-120 kVp contrast enhancement conversion factor (Ec) was calculated at 0.81. Optimal VCE (250 to 450 HU) and diagnostic image quality were obtained with significant reductions in TID (32.1%) and radiation dose (38.5%) when using 100 kVp and personalized contrast volume calculation algorithm compared with 120 kVp and routine contrast protocols (P<0.05). Conclusions The proposed algorithm could significantly reduce TID and radiation exposure while maintaining optimal VCE and image quality in CCTA with 100 kVp protocol.
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Affiliation(s)
- Sock Keow Tan
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,University of Malaya Research Imaging Centre (UMRIC), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kwan Hoong Ng
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,University of Malaya Research Imaging Centre (UMRIC), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Chai Hong Yeong
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Malaysia
| | - Raja Rizal Azman Raja Aman
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,University of Malaya Research Imaging Centre (UMRIC), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Fadhli Mohamed Sani
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,University of Malaya Research Imaging Centre (UMRIC), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Yang Faridah Abdul Aziz
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,University of Malaya Research Imaging Centre (UMRIC), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Zhonghua Sun
- Discipline of Medical Radiation Sciences, Curtin University, Perth, Australia
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Nautiyal A, Mondal T, Mukherjee A, Mitra D, Kaushik A, Goel HC, Goel A, Dey SK. Quantification of DNA damage in patients undergoing non-contrast and contrast enhanced whole body PET/CT investigations using comet assay and micronucleus assay. Int J Radiat Biol 2019; 95:710-719. [PMID: 30707050 DOI: 10.1080/09553002.2019.1577569] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Objective: To quantify DNA damage in patients undergoing non-contrast and contrast-enhanced 18F-FDG PET/CT whole body positron emission tomography/computed tomography (WB PET/CT) investigations using comet assay technique and micronucleus assay, and to study the effect of other baseline parameters of patients on DNA damage. Methodology: Eighty-four patients referred for 18F-FDG PET/CT investigation were included in the study of which 44 patients underwent contrast-enhanced WB PET/CT and 40 patients underwent non-contrast WB PET/CT investigations. The investigations were performed on Discovery 690 PET/CT. For contrast-enhanced investigation, Omnipaque300 was injected intravenously based on the patient body weight. Absorbed dose resulting from the intravenous administration of 18F-FDG was estimated using the ICRP 106 dose coefficients. Radiation dose from the acquisition of CT scans was estimated using CT dose index and dose-length product. Blood samples were collected from the patients for DNA damage analysis. Comet assay and MN assay was used to assess the DNA damage. The Differences in the comet TM (Tail Moment) and MNBC % in both groups were calculated. Result: The radiation dose received by the study population during 18F-FDG WB PET/CT examination was 27.03 ± 2.33 mSv. Comet TM and percentage frequency of MNBC % was 65.22 ± 35.42 and 18.55 ± 10.14, respectively in the patients injected with contrast and 42.49 ± 28.52 and 13.76 ± 7.52 for non-contrast group. Significant increase in DNA damage was observed in the contrast group as compared to non-contrast group. Significant association was observed between patient weight, contrast volume and TM and MNBC%. Baseline parameters of the patients did not show significant correlation with TM and MNBC%. Conclusion: The patients undergoing contrast-enhanced WB PET/CT investigations have demonstrated higher DNA damage. The DNA damage was also observed to be more in heavier patients. The other baseline parameters of patients like age, sex, CBG, serum creatinine did not show any correlation with DNA damage.
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Affiliation(s)
- Amit Nautiyal
- a Institute of Nuclear Medicine & Molecular Imaging , AMRI Hospitals , Kolkata , India
| | - Tanmoy Mondal
- b Department of Biotechnology , Maulana Abul Kalam Azad University of Technology , Kolkata , India
| | - Anirban Mukherjee
- a Institute of Nuclear Medicine & Molecular Imaging , AMRI Hospitals , Kolkata , India
| | - Deepanjan Mitra
- a Institute of Nuclear Medicine & Molecular Imaging , AMRI Hospitals , Kolkata , India
| | - Aruna Kaushik
- c Institute of Nuclear Medicine & Allied Sciences , Delhi , India
| | | | - Alpana Goel
- e Amity Institute of Nuclear Science & Technology, Amity University , Noida , India
| | - Subrata Kumar Dey
- b Department of Biotechnology , Maulana Abul Kalam Azad University of Technology , Kolkata , India
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Patino M, Parakh A, Lo GC, Agrawal M, Kambadakone AR, Oliveira GR, Sahani DV. Virtual Monochromatic Dual-Energy Aortoiliac CT Angiography With Reduced Iodine Dose: A Prospective Randomized Study. AJR Am J Roentgenol 2019; 212:467-474. [DOI: 10.2214/ajr.18.19935] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Affiliation(s)
- Manuel Patino
- Department of Radiology, Division of Abdominal Imaging, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA 02114
| | - Anushri Parakh
- Department of Radiology, Division of Abdominal Imaging, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA 02114
| | - Grace C. Lo
- Department of Radiology, Division of Abdominal Imaging, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA 02114
| | - Mukta Agrawal
- Department of Radiology, Division of Abdominal Imaging, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA 02114
| | - Avinash R. Kambadakone
- Department of Radiology, Division of Abdominal Imaging, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA 02114
| | - George R. Oliveira
- Department of Radiology, Division of Abdominal Imaging, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA 02114
| | - Dushyant V. Sahani
- Department of Radiology, Division of Abdominal Imaging, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA 02114
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Van Cauteren T, Van Gompel G, Nieboer KH, Willekens I, Evans P, Macholl S, Droogmans S, de Mey J, Buls N. Improved enhancement in CT angiography with reduced contrast media iodine concentrations at constant iodine dose. Sci Rep 2018; 8:17493. [PMID: 30504863 PMCID: PMC6269421 DOI: 10.1038/s41598-018-35918-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 11/09/2018] [Indexed: 11/09/2022] Open
Abstract
The study objective is to investigate the impact of a wide range of contrast media (CM) iodine concentrations on CT enhancement at constant total iodine dose (TID) and iodine delivery rate (IDR). Seven injection protocols, based on different iodine concentrations ranging from 120 to 370 mg I/mL, were assessed on 4 minipigs at a constant TID of 320 mg I/kg and IDR of 0.64 g I/s. Dynamic images were acquired on a clinical 64-slice MDCT scanner for 120 s with the abdominal aorta, vena cava inferior and liver parenchyma in the field-of-view. Maximal enhancement, time-to-peak and peak width were assessed. The enhancement curve characteristics were correlated with CM iodine concentration. In particular, CM with lower iodine concentrations yielded a significant increased maximal enhancement and peak width compared to the standard-of-care concentrations: e.g. in the aorta, 245 HU maximal enhancement and 9.2 s peak width with the 320 mg I/mL iodine concentration increased to 291 HU and 16.1 s with 160 mg I/mL. When maintaining a constant TID and IDR, by compensating injection rate and volume, injection of a CM with reduced iodine concentration results in a diagnostically beneficial higher maximal enhancement and longer enhancement peak duration.
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Affiliation(s)
- Toon Van Cauteren
- Departement of Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussels (UZ Brussel), Laarbeeklaan 101, 1090, Brussels, Belgium.
| | - Gert Van Gompel
- Departement of Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussels (UZ Brussel), Laarbeeklaan 101, 1090, Brussels, Belgium
| | - Koenraad H Nieboer
- Departement of Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussels (UZ Brussel), Laarbeeklaan 101, 1090, Brussels, Belgium
| | - Inneke Willekens
- Departement of Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussels (UZ Brussel), Laarbeeklaan 101, 1090, Brussels, Belgium
| | - Paul Evans
- Departement of Imaging R&D, GE Healthcare Life Sciences, Amersham, Buckinghamshire, England
| | - Sven Macholl
- Departement of Imaging R&D, GE Healthcare Life Sciences, Amersham, Buckinghamshire, England
| | - Steven Droogmans
- Departement of Cardiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussels (UZ Brussel), Laarbeeklaan 101, 1090, Brussels, Belgium
| | - Johan de Mey
- Departement of Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussels (UZ Brussel), Laarbeeklaan 101, 1090, Brussels, Belgium
| | - Nico Buls
- Departement of Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussels (UZ Brussel), Laarbeeklaan 101, 1090, Brussels, Belgium
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Phillips J, Mihai G, Hassonjee SE, Raj SD, Palmer MR, Brook A, Zhang D. Comparative Dose of Contrast-Enhanced Spectral Mammography (CESM), Digital Mammography, and Digital Breast Tomosynthesis. AJR Am J Roentgenol 2018; 211:839-846. [DOI: 10.2214/ajr.17.19036] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Affiliation(s)
- Jordana Phillips
- Department of Radiology, Harvard Medical School and Beth Israel Deaconess Medical Center, 330 Brookline Ave, 4th Fl, Boston, MA 02215
| | - Georgeta Mihai
- Department of Radiology, Harvard Medical School and Beth Israel Deaconess Medical Center, 330 Brookline Ave, 4th Fl, Boston, MA 02215
| | - Sarah Esaa Hassonjee
- Department of Radiology, Harvard Medical School and Beth Israel Deaconess Medical Center, 330 Brookline Ave, 4th Fl, Boston, MA 02215
| | - Sean D. Raj
- Department of Radiology, Harvard Medical School and Beth Israel Deaconess Medical Center, 330 Brookline Ave, 4th Fl, Boston, MA 02215
| | - Matthew R. Palmer
- Department of Radiology, Harvard Medical School and Beth Israel Deaconess Medical Center, 330 Brookline Ave, 4th Fl, Boston, MA 02215
| | - Alexander Brook
- Department of Radiology, Harvard Medical School and Beth Israel Deaconess Medical Center, 330 Brookline Ave, 4th Fl, Boston, MA 02215
| | - Da Zhang
- Department of Radiology, Harvard Medical School and Beth Israel Deaconess Medical Center, 330 Brookline Ave, 4th Fl, Boston, MA 02215
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Shi L, Fujioka K, Sakurai-Ozato N, Fukumoto W, Satoh K, Sun J, Awazu A, Tanaka K, Ishida M, Ishida T, Nakano Y, Kihara Y, Hayes CN, Aikata H, Chayama K, Ito T, Awai K, Tashiro S. Chromosomal Abnormalities in Human Lymphocytes after Computed Tomography Scan Procedure. Radiat Res 2018; 190:424-432. [PMID: 30040044 DOI: 10.1667/rr14976.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The incidence of chromosomal abnormalities and cancer risk correlates well with the radiation dose after exposure to moderate- to high-dose ionizing radiation. However, the biological effects and health risks at less than 100 mGy, e.g., from computed tomography (CT) have not been ascertained. To investigate the biological effects of low-dose exposure from a CT procedure, we examined chromosomal aberrations, dicentric and ring chromosomes (dic+ring), in peripheral blood lymphocytes (PBLs), using FISH assays with telomere and centromere PNA probes. In 60 non-cancer patients exposed to CT scans, the numbers of dicentric and ring chromosomes were significantly increased with individual variation. The individual variations in the increment of dicentric and ring chromosomes after CT procedures were confirmed using PNA-FISH analysis of PBLs from 15 healthy volunteers after in vitro low-dose exposure using a 137Cs radiation device. These findings strongly suggest that appropriate medical use of low-dose radiation should consider individual differences in radiation sensitivity.
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Affiliation(s)
- Lin Shi
- Departments of a Cellular Biology
| | | | | | - Wataru Fukumoto
- g Department of Diagnostic Radiology, Hiroshima University, Hiroshima 734-8553, Japan
| | - Kenichi Satoh
- c Environmetrics and Biometrics, Research Institute for Radiation Biology Medicine
| | | | - Akinori Awazu
- h Department of Mathematics.,i Research Center for the Mathematics on Chromatin Live Dynamics, Hiroshima University, Higashi Hiroshima 739-8530, Japan
| | | | - Mari Ishida
- d Departments of Cardiovascular Physiology and Medicine
| | - Takafumi Ishida
- j Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima 960-1295, Japan
| | | | | | - C Nelson Hayes
- f Gastroenterology and Metabolism, Biomedical Sciences, Graduate School of Biomedical and Health Sciences
| | - Hiroshi Aikata
- f Gastroenterology and Metabolism, Biomedical Sciences, Graduate School of Biomedical and Health Sciences
| | - Kazuaki Chayama
- f Gastroenterology and Metabolism, Biomedical Sciences, Graduate School of Biomedical and Health Sciences
| | - Takashi Ito
- k Department of Biochemistry, Nagasaki University School of Medicine, Nagasaki 852-8523, Japan
| | - Kazuo Awai
- g Department of Diagnostic Radiology, Hiroshima University, Hiroshima 734-8553, Japan
| | - Satoshi Tashiro
- Departments of a Cellular Biology.,i Research Center for the Mathematics on Chromatin Live Dynamics, Hiroshima University, Higashi Hiroshima 739-8530, Japan
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47
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What is the underestimation of radiation dose to the pediatric thyroid gland from contrast enhanced CT, if contrast medium uptake is not taken into account? Phys Med 2018; 49:95-98. [DOI: 10.1016/j.ejmp.2018.05.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 05/07/2018] [Accepted: 05/08/2018] [Indexed: 11/17/2022] Open
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48
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Abadi E, Segars WP, Sturgeon GM, Harrawood B, Kapadia A, Samei E. Modeling "Textured" Bones in Virtual Human Phantoms. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2018; 3:47-53. [PMID: 31559375 DOI: 10.1109/trpms.2018.2828083] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The purpose of this study was to develop detailed and realistic models of the cortical and trabecular bones in the spine, ribs, and sternum and incorporate them into the library of virtual human phantoms (XCAT). Cortical bone was modeled by 3D morphological erosion of XCAT homogenously defined bones with an average thickness measured from the CT dataset upon which each individual XCAT phantom was based. The trabecular texture was modeled using a power law synthesis algorithm where the parameters were tuned using high-resolution anatomical images of the Human Visible Female. The synthesized bone textures were added into the XCAT phantoms. To qualitatively evaluate the improved realism of the bone modeling, CT simulations of the XCAT phantoms were acquired with and without the textured bone modeling. The 3D power spectrum of the anatomical images exhibited a power law behavior (R2 = 0.84), as expected in fractal and porous textures. The proposed texture synthesis algorithm was able to synthesize textures emulating real anatomical images, with the simulated CT images with the prototyped bones were more realistic than those simulated with the original XCAT models. Incorporating intra-organ structures, the "textured" phantoms are envisioned to be used to conduct virtual clinical trials in the context of medical imaging in cases where the actual trials are infeasible due to the lack of ground truth, cost, or potential risks to the patients.
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Affiliation(s)
- Ehsan Abadi
- Department of Electrical and Computer Engineering, and the Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University, Durham, NC, 27705 USA
| | - William P Segars
- Carl E. Ravin Advanced Imaging Laboratories, the Department of Radiology, the Medical Physics Graduate Program, and the Department of Biomedical Engineering, Duke University, Durham, NC, 27705 USA
| | - Gregory M Sturgeon
- Carl E. Ravin Advanced Imaging Laboratories and the Department of Radiology, Duke University Medical Center, Durham, NC, 27705 USA
| | - Brian Harrawood
- Carl E. Ravin Advanced Imaging Laboratories and Department of Radiology, Duke University Medical Center, Durham, NC, 27705 USA
| | - Anuj Kapadia
- Carl E. Ravin Advanced Imaging Laboratories, the Department of Radiology, and the Medical Physics Graduate Program, Durham, NC, 27705 USA
| | - Ehsan Samei
- Carl E. Ravin Advanced Imaging Laboratories, the Department of Electrical and Computer Engineering, the Department of Radiology, the Department of Biomedical Engineering, the Medical Physics Graduate Program, and the Department of Physics, Duke University, Durham, NC, 27705 USA
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49
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Boone JM, Hernandez AM. The Effect of Iodine-based Contrast Material on Radiation Dose at CT: It's Complicated. Radiology 2018; 283:624-627. [PMID: 28514218 DOI: 10.1148/radiol.2017170611] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- John M Boone
- From the Department of Radiology, UC Davis Medical Center, 4860 Y St, Suite 3100, Sacramento, CA 95817
| | - Andrew M Hernandez
- From the Department of Radiology, UC Davis Medical Center, 4860 Y St, Suite 3100, Sacramento, CA 95817
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50
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Segars WP, Tsui BMW, Jing Cai, Fang-Fang Yin, Fung GSK, Samei E. Application of the 4-D XCAT Phantoms in Biomedical Imaging and Beyond. IEEE TRANSACTIONS ON MEDICAL IMAGING 2018; 37:680-692. [PMID: 28809677 PMCID: PMC5809240 DOI: 10.1109/tmi.2017.2738448] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The four-dimensional (4-D) eXtended CArdiac-Torso (XCAT) series of phantoms was developed to provide accurate computerized models of the human anatomy and physiology. The XCAT series encompasses a vast population of phantoms of varying ages from newborn to adult, each including parameterized models for the cardiac and respiratory motions. With great flexibility in the XCAT's design, any number of body sizes, different anatomies, cardiac or respiratory motions or patterns, patient positions and orientations, and spatial resolutions can be simulated. As such, the XCAT phantoms are gaining a wide use in biomedical imaging research. There they can provide a virtual patient base from which to quantitatively evaluate and improve imaging instrumentation, data acquisition, techniques, and image reconstruction and processing methods which can lead to improved image quality and more accurate clinical diagnoses. The phantoms have also found great use in radiation dosimetry, radiation therapy, medical device design, and even the security and defense industry. This review paper highlights some specific areas in which the XCAT phantoms have found use within biomedical imaging and other fields. From these examples, we illustrate the increasingly important role that computerized phantoms and computer simulation are playing in the research community.
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