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Akyea-Larbi KO, Hasford F, Inkoom S, Tetteh MA, Gyekye PK. Evaluation of organ and effective doses using anthropomorphic phantom: A comparison between experimental measurement and a commercial dose calculator. Radiography (Lond) 2024; 30:1-5. [PMID: 37864985 DOI: 10.1016/j.radi.2023.10.003] [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: 08/10/2023] [Revised: 10/02/2023] [Accepted: 10/03/2023] [Indexed: 10/23/2023]
Abstract
INTRODUCTION The aim of this study was to experimentally measure organ doses for computed tomography (CT) procedures using thermoluminescence dosimeters (TLDs) on a RANDO anthropomorphic phantom and verify the measured doses using CT-Expo software. METHODS The phantom was irradiated using clinical CT scan protocols routinely used for specific procedures in the radiology department. Fifty TLD chips were used in this study. The scanning parameters (kVp, mA, s) used to scan the phantom were used as input parameters for CT-Expo dose estimations. RESULTS The TLD measured organ doses varied between 3.97 mGy for the esophagus and 56.22 mGy for the brain. High doses were recorded in the brain (37.80-56.22 mGy) and the eye lens (29.94-36.16 mGy). Comparing the organ dose measurements between TLD and CT-Expo, the maximum organ dose difference was obtained for the eye lens. A comparison between the two methods for the other organs were all less than 32 %. The effective doses from the TLD measurements for the head, chest, and abdominopelvic CT examinations were 2.78, 6.67, and 17 mSv, respectively and CT-Expo were 2.20, 10.30, and 16.70 mSv, respectively. CONCLUSION The experimental and computational results are comparable, and the reliability of the TLD measurements and CT-Expo dose calculator has been proven. IMPLICATIONS FOR STUDY A reason for the difference in dose measurements between the two methods has been attributed to the dissimilarity in the organ position in the Rando anthropomorphic phantom and the standard mathematical phantom used by CT-Expo. The experimental and computational results have been found to be comparable.
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Affiliation(s)
- K O Akyea-Larbi
- Department of Medical Physics, School of Nuclear and Allied Sciences, University of Ghana, Accra, Ghana; Radiation Protection Institute, Ghana Atomic Energy Commission, Accra, Ghana.
| | - F Hasford
- Department of Medical Physics, School of Nuclear and Allied Sciences, University of Ghana, Accra, Ghana; Radiological and Medical Sciences Research Institute, Ghana Atomic Energy Commission Accra, Ghana
| | - S Inkoom
- Department of Medical Physics, School of Nuclear and Allied Sciences, University of Ghana, Accra, Ghana; Radiation Protection Institute, Ghana Atomic Energy Commission, Accra, Ghana
| | - M A Tetteh
- Department of Medical Physics, School of Nuclear and Allied Sciences, University of Ghana, Accra, Ghana; Radiology Department, Akershus University Hospital, Oslo, Norway
| | - P K Gyekye
- Department of Medical Physics, School of Nuclear and Allied Sciences, University of Ghana, Accra, Ghana; Radiological and Non-Ionizing Directorate, Nuclear Regulatory Authority, Accra, Ghana
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Vazquez-Bañuelos J, Campillo-Rivera GE, Vega-Carrillo HR, Torres-Cortes CO, Marquez-Mata CA, Vasquez-Arteaga M. Spectra, fluence and absorbed doses in sensitive organs due to scattered X-rays during a chest CT. Appl Radiat Isot 2023; 194:110723. [PMID: 36804700 DOI: 10.1016/j.apradiso.2023.110723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 01/10/2023] [Accepted: 02/10/2023] [Indexed: 02/13/2023]
Abstract
The use of ionizing radiation for the treatment and diagnosis of diseases is becoming more frequent. The technologies associated with diagnostic imaging are constantly evolving, allowing faster and cheaper diagnoses to benefit the patient. However, this has caused an increase in the exposure to ionizing radiation of patients and health professionals. One of the diagnostic techniques for obtaining high-resolution anatomical images of patients is computed tomography (CT). Due to the detail and quality of the images obtained with CT, its use is becoming more frequent. The information provided by these images allows the specialist to make better diagnoses; however, exposure to X-rays deposits a dose in the patient. CT represents approximately 20% of all X-ray examinations but it is responsible for 70% of the medical dose accumulated by the patient. During the acquisition of the images, the highest dose is deposited in the area of the body whose image is to be obtained. During the incidence of X-rays, there is dispersion of these that reach sensitive organs whose dose is not evaluated. The objective of this work was to estimate, using Monte Carlo methods, the fluence and X-ray spectra and to obtain a factor that allows knowing the absorbed dose in sensitive organs due to scattered radiation during a chest CT. With the MCNP5 code, the CT equipment and a hybrid anthropomorphic phantom, type BOMAB it was found that the absorbed dose in these organs depends on the size of the organ and the distance between the organ and the surface of the slice on the thorax where the X-rays are incident.
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Affiliation(s)
- Joel Vazquez-Bañuelos
- Programa de Doctorado en Ingenieria y Tecnologia Aplicada, Unidad Academica de Ingenieria Electrica, Universidad Autonoma de Zacatecas, Av. Ramon Lopez Velarde 800, Col. Centro, 98000, Zacatecas, Zac, Mexico.
| | - Guillermo Eduardo Campillo-Rivera
- Programa de Doctorado en Ingenieria y Tecnologia Aplicada, Unidad Academica de Ingenieria Electrica, Universidad Autonoma de Zacatecas, Av. Ramon Lopez Velarde 800, Col. Centro, 98000, Zacatecas, Zac, Mexico
| | - Hector Rene Vega-Carrillo
- Programa de Doctorado en Ingenieria y Tecnologia Aplicada, Unidad Academica de Ingenieria Electrica, Universidad Autonoma de Zacatecas, Av. Ramon Lopez Velarde 800, Col. Centro, 98000, Zacatecas, Zac, Mexico; Unidad Académica de Estudios Nucleares, Universidad Autonoma de Zacatecas, Ciprés 10, Fracc. La Peñuela, 98060, Zacatecas, Zac, Mexico
| | - Carina Oliva Torres-Cortes
- Unidad Academica de Ingenieria I, Universidad Autonoma de Zacatecas, Av. Ramon Lopez Velarde 800, Col. Centro, 98000, Zacatecas, Zac, Mexico
| | - Claudia Angelica Marquez-Mata
- ITM/Instituto Tecnologico de Aguascalientes, Av. Adolfo Lopez Mateos Ote. 1801, Bona Gens, 20256, Aguascalientes, Ags, Mexico
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Cancer risk in healthy patients who underwent chest tomography comparing three different technologies. Appl Radiat Isot 2023; 193:110625. [PMID: 36680979 DOI: 10.1016/j.apradiso.2022.110625] [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: 02/28/2022] [Revised: 12/15/2022] [Accepted: 12/20/2022] [Indexed: 12/30/2022]
Abstract
This research aimed to estimate the risk of cancer associated with patients without previous disease undergoing chest tomography. Siemens CT scanners have 6, 64, and 128 detectors. The Biologic Effects of Ionizing Radiation Reports - BEIR VII methodology was used. The study presented a sample of 64 patients aged between 18 and 80 years, in the city of Belo Horizonte, Minas Gerais - Brazil. The IMPACT CT software and CalDose X CT Online were used to calculate the absorbed and equivalent dose from the Volumetric Computed Tomography Dose Index - CTDIvol (mGy) and Dose Length Product - DLP values provided by the equipment. CT-Expo Software was also used to estimate Specific Dose Estimates (SSDEs) values. The CTDvol results for the MG1, MG,2 and MG3 Diagnostic Centers in mGy were respectively 4.369 ± 1.352, 6.99 4 ± 1.53,3 and 9.984 ± 2.282 and the SSDE values were 3.800, 6.40,0 and 9,.500. The values for the equivalent dose, at the MG2 Diagnostic Center, by IMPACT CT, in (mSv) for the breasts, esophagus, heart, thyroid, lung and thymus were respectively 3.9, 5.7, 4.7, 1.0, 4.8 and 5.7. The CalDose Software, for the same equipment and the same organs, in mSv, estimated the values 7.4, 9.4, 11.1, 5.3, 10.8 and 11.3 for women and 7.1, 9.3, 11.0, 5.3, 10.2 and 10.9 for men. The estimated risk of cancer decreased according to the patient's age, but with a higher incidence for females. The use of each software must be carefully analyzed to avoid undue values due to the particularities of each one. The results also showed that the risk of developing cancer due to radiation decreases with patient age and is higher in females.
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Lestari YM, Anam C, Sutanto H, Arifin Z, Alkian I, Suyudi I, Dougherty G. Evaluation of silicone rubber-lead shield's effectiveness in protecting the breast during thoracic CT. Biomed Phys Eng Express 2023; 9. [PMID: 36689768 DOI: 10.1088/2057-1976/acb551] [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: 11/15/2022] [Accepted: 01/23/2023] [Indexed: 01/24/2023]
Abstract
Radiation of thoracic computed tomography (CT) involves the breast although it is not considered an organ of interest. According to the International Commission on Radiological Protection (ICRP) No. 103, the breast is an organ with a high level of sensitivity when interacting with x-rays, increasing the potential risk of breast cancer. Therefore, the radiation dose must be optimized while maintaining image quality. The dose optimization can be accomplished using a radiation shield. This study aims to determine the effect of silicone rubber (SR)-lead (Pb) in various thicknesses as an alternative protective material limiting dose and preserving the image quality of the breast in thoracic CT. SR-Pb was made from SR and Pb by a simple method. The SR-Pb had thicknesses of 3, 6, 9, and 12 mm. The breast dose was measured using a CT dose profiler on the surface of the breast phantom. The CT number and the noise level of the resulting image were determined quantitatively. The dose without the radiation shield was 5.4 mGy. The doses measured using shielding with thicknesses of 3, 6, 9, and 12 mm were 5.2, 4.5, 4.3, and 3.3 mGy, respectively. Radiation shielding with a thickness of 12 mm reduced breast surface dose by up to 38%. The CT numbers and noise levels for the left and right breast phantom images were almost the same as those without radiation shields indicating there were only slight artifacts in the image. Therefore, SR-Pb is considered a good shielding material which can be pplied in a clinical setting by placing it directly on the breast surface for dose optimization.
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Affiliation(s)
| | - Choirul Anam
- Department of Physics, Diponegoro University, Semarang, Indonesia
| | - Heri Sutanto
- Department of Physics, Diponegoro University, Semarang, Indonesia.,Smart Material Research Center, Diponegoro University, Semarang, Indonesia
| | - Zaenal Arifin
- Department of Physics, Diponegoro University, Semarang, Indonesia
| | - Ilham Alkian
- Smart Material Research Center, Diponegoro University, Semarang, Indonesia
| | - Imam Suyudi
- Radiology Installation, Kardinah Hospital, Tegal, Indonesia
| | - Geoff Dougherty
- Department of Applied Physics and Medical Imaging, California State University Channel Islands, Camarillo, CA 93012, United States of America
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Sulieman A, Tamam N, Elnour A, Alkhorayef M, Babikir E, Al-Mohammed H, Abuhadi N, Khandaker MU, A.Bradley D. Effective radiation dose and radiogenic cancer risk during contrast enhanced abdominal computed tomography examinations. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Measurement uncertainty analysis of radiophotoluminescent glass dosimeter reader system based on GD-352M for estimation of protection quantity. NUCLEAR ENGINEERING AND TECHNOLOGY 2022. [DOI: 10.1016/j.net.2021.08.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Kayun Z, Abdul Karim MK, Harun HH, Shaari AH, Mahmud R, Hamid HA, Sabarudin A, Chew MT. Radiation doses and size-specific dose estimate from CT brain examinations according to head sizes in a tertiary hospital in Malaysia. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2021.109694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Evaluation of Organ Dose and Image Quality Metrics of Pediatric CT Chest-Abdomen-Pelvis (CAP) Examination: An Anthropomorphic Phantom Study. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11052047] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The aim of this study is to investigate the impact of CT acquisition parameter setting on organ dose and its influence on image quality metrics in pediatric phantom during CT examination. The study was performed on 64-slice multidetector CT scanner (MDCT) Siemens Definition AS (Siemens Sector Healthcare, Forchheim, Germany) using various CT CAP protocols (P1–P9). Tube potential for P1, P2, and P3 protocols were fixed at 100 kVp while P4, P5, and P6 were fixed at 80 kVp with used of various reference noise values. P7, P8, and P9 were the modification of P1 with changes on slice collimation, pitch factor, and tube current modulation (TCM), respectively. TLD-100 chips were inserted into the phantom slab number 7, 9, 10, 12, 13, and 14 to represent thyroid, lung, liver, stomach, gonads, and skin, respectively. The image quality metrics, signal to noise ratio (SNR) and contrast to noise ratio (CNR) values were obtained from the CT console. As a result, this study indicates a potential reduction in the absorbed dose up to 20% to 50% along with reducing tube voltage, tube current, and increasing the slice collimation. There is no significant difference (p > 0.05) observed between the protocols and image metrics.
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Muhammad N, Sabarudin A, Ismail N, Karim M. A systematic review and meta-analysis of radiation dose exposure from computed tomography examination of thorax-abdomen-pelvic regions among paediatric population. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2020.109148] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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The influence of iterative reconstruction level on image quality and radiation dose in CT pulmonary angiography examinations. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2020.108989] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Yang MX, Chen B, Zhang YP, Zhao ZH. Feasibility of customizing titanium implant with three-dimensional CT imaging of low dose in skull. Medicine (Baltimore) 2020; 99:e21009. [PMID: 32664105 PMCID: PMC7360305 DOI: 10.1097/md.0000000000021009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
OBJECT To explore the feasibility and practicability of making virtual three-dimensional model of skull defect and customizing titanium implant by skull three-dimensional CT examination of low dose. METHODS Sixty patients with skull defects who underwent skull three-dimensional CT before cranioplasty were randomly divided into 4 groups: group A (conventional dose 120 peak Kilovoltage (kVp), 150 tube current time product (mAs)), low dose group B (120 kVp, 50 mAs), low dose group C (100 kVp, 50 mAs), low dose group D (100 kVp, 30 mAs). After the scanning, we compared radiation doses and image quality among the groups. The CT data were sent to the reconstruction company to produce accurate titanium implants, and neurosurgeons performed cranioplasty. After the operation, patients immediately underwent head CT scans to confirm the accuracy of the implantation position, and a series of clinical functions were evaluated. RESULTS There were significant differences in dose length product (DLP) and effective dose (ED) among the 4 groups (P < .001). The volume CT dose index (CDTIvol), DLP, and ED in group D were, respectively, 87.1%, 86.9%, and 87.3% lower than those in group A (P < .001). All images quality were at or above the general level, and there was no statistical difference (P > .05). Titanium implants were successfully manufactured, every cranioplasty was carried out smoothly, and the clinical function of patients recovered well. CONCLUSION Customizing titanium implant with three-dimensional CT imaging of low dose in skull not only met the clinical requirements, but also significantly reduced the radiation dose and hazard.
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Affiliation(s)
- Min-Xia Yang
- Department of Radiology, Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, Zhejiang Province, China
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Gharbi S, Labidi S, Mars M. AUTOMATIC BRAIN DOSE ESTIMATION IN COMPUTED TOMOGRAPHY USING PATIENT DICOM IMAGES. RADIATION PROTECTION DOSIMETRY 2020; 188:536-542. [PMID: 32043150 DOI: 10.1093/rpd/ncaa006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 12/03/2019] [Accepted: 01/13/2020] [Indexed: 06/10/2023]
Abstract
This study aims to develop an Automatic Brain Dose Estimation (ABDE) methodology for head computed tomography examinations. The ABDE is to be applied first to an anthropomorphic Alderson phantom to obtain a Correction factor (Cf) between the ABDE and the direct absorbed brain dose using dosemeters positioned within the anthropomorphic phantom. Then, in order to estimate the correct brain dose for patient, the Cf was multiplied by the mean ABDE values for each patient. Results were compared to those registered with a mathematical simulation phantom using CT-Expo V 2.4 software. Results showed no significant difference between the correct ABDE values and the CT-Expo values with a mean percent difference of 2.54 ± 0.01%. In conclusion, ABDE yields a correct estimation of brain dose, taking into account the size and attenuation of the irradiated region. Thus, it is clinically recommended for accurate patient brain dose assessment.
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Affiliation(s)
- Souha Gharbi
- Université Tunis EL Manar, Institut Supérieur des Technologies Médicales de Tunis, Laboratoire de recherche de Biophysique et de Technologies Médicales, 9, Avenue du Docteur Z. Essafi, Tunis 1006, Tunisia
| | - Salam Labidi
- Université Tunis EL Manar, Institut Supérieur des Technologies Médicales de Tunis, Laboratoire de recherche de Biophysique et de Technologies Médicales, 9, Avenue du Docteur Z. Essafi, Tunis 1006, Tunisia
| | - Mokhtar Mars
- Université Tunis EL Manar, Institut Supérieur des Technologies Médicales de Tunis, Laboratoire de recherche de Biophysique et de Technologies Médicales, 9, Avenue du Docteur Z. Essafi, Tunis 1006, Tunisia
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Harun HH, Karim MKA, Abbas Z, Sabarudin A, Muniandy SC, Ibahim MJ. Effect of iterative reconstruction algorithm levels on noise index and figure-of-merit in CT pulmonary angiography examinations. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2020; 28:893-903. [PMID: 32741801 DOI: 10.3233/xst-200699] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
PURPOSE To evaluate the influence of iterative reconstruction (IR) levels on Computed Tomography (CT) image quality and to establish Figure of Merit (FOM) value for CT Pulmonary Angiography (CTPA) examinations. METHODS Images of 31 adult patients who underwent CTPA examinations in our institution from March to April 2019 were retrospectively collected. Other data, such as scanning parameters, radiation dose and body habitus information from the subjects were also recorded. Six different levels of IR were applied to the volume data of the subjects. Five circles of the region of interest (ROI) were drawn in five different arteries namely, pulmonary trunk, right pulmonary artery, left pulmonary artery, ascending aorta and descending aorta. The mean Signal-to-noise ratio (SNR) was obtained, and the FOM was calculated in a fraction of the SNR2 divided by volume-weighted CT dose index (CTDIvol) and SNR2 divided by the size-specific dose estimates (SSDE). RESULTS Overall, we observed that the mean value of CTDIvol and SSDE were 13.79±7.72 mGy and 17.25±8.92 mGy, respectively. Notably, SNR values significantly increase with increase of the IR level (p < 0.05). There are also significant differences (p < 0.05) in the FOM for both SNR2/SSDE and SNR2/CTDIvol attained in different IR levels. CONCLUSION We successfully evaluate the value of radiation dose and image quality performance and set up a figure of merit for both parameters to further verify scanning protocols by radiology personnel.
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Affiliation(s)
- H H Harun
- Department of Physics, Faculty of Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - M K A Karim
- Department of Physics, Faculty of Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Z Abbas
- Department of Physics, Faculty of Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - A Sabarudin
- Department of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysiainstitution>
| | - S C Muniandy
- Department of Radiology, Hospital Kuala Lumpur, Jalan Pahang, Kuala Lumpur, Malaysia
| | - M J Ibahim
- Department of Biochemistry and Molecular Medicine, Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh, Selangor, Malaysia
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Muhammad N, Karim M, Hassan H, Kamarudin M, Wong J, Ibahim M. Estimation of effective dose and organ cancer risk from paediatric computed tomography thorax – Abdomen - Pelvis examinations. Radiat Phys Chem Oxf Engl 1993 2019. [DOI: 10.1016/j.radphyschem.2019.108438] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Karim MKA, Sabarudin A, Muhammad NA, Ng KH. A comparative study of radiation doses between phantom and patients via CT angiography of the intra-/extra-cranial, pulmonary, and abdominal/pelvic arteries. Radiol Phys Technol 2019; 12:374-381. [PMID: 31468370 DOI: 10.1007/s12194-019-00532-8] [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] [Received: 02/18/2019] [Revised: 08/09/2019] [Accepted: 08/10/2019] [Indexed: 10/26/2022]
Abstract
This study aimed to evaluate effective dose and size-specific dose estimate (SSDE) of computed tomography angiography (CTA) examination using an anthropomorphic phantom. We included three CTA examination protocols to evaluate the intra- and extra-cranial arteries, pulmonary artery (CTPA), and abdominal vessels. Patient SSDEs were measured retrospectively to estimate patient dose, relative to the bodyweight of the patient and volume CT dose index (CTDIvol). Our findings revealed that the highest dose was absorbed by the left lobe of the thyroid gland during intra-/extra-cranial CTA and CTPA, that is, 14.11 ± 0.24 mGy and 16.20 ± 3.95 mGy, respectively. However, the highest absorbed dose in abdominal/pelvic CTA was the gonads (8.98 ± 0.30 mGy), while other radiosensitive organs in intra- and extra-cranial CTA, CTPA, and abdominal/pelvic CTA did not demonstrate significant differences between organs/structures with p value 0.88, 0.11, and 0.54, respectively. The estimated effective dose in intra-/extra-cranial CTA was lower in patients (0.80 ± 0.60 mSv) than in the phantom (0.83 mSv), but it was the opposite for CTPA, with the effective dose being higher in patients (7.54 ± 3.09 mSv) than in the phantom (6.68 mSv). Similar to the effective dose, only CTPA SSDEs were significantly higher in men than in women (19.74 ± 4.79 mGy versus 7.9 mGy). Effective dose and SSDE are clinically relevant parameters that can help estimate a more accurate patient dose based on a patient's size.
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Affiliation(s)
- M K A Karim
- Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.
| | - A Sabarudin
- Programme of Diagnostic Imaging and Radiotherapy, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, 56000, Kuala Lumpur, Malaysia
| | - N A Muhammad
- Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - K H Ng
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
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A comparison study of radiation effective dose in ECG-Gated Coronary CT Angiography and calcium scoring examinations performed with a dual-source CT scanner. Sci Rep 2019; 9:4374. [PMID: 30867480 PMCID: PMC6416329 DOI: 10.1038/s41598-019-40758-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 02/21/2019] [Indexed: 11/08/2022] Open
Abstract
In this report we have evaluated radiation effective dose received by patients during ECG-gated CCTA examinations based on gender, heart rate, tube voltage protocol and body mass index (BMI). A total of 1,824 patients were retrospectively recruited (1,139 men and 685 women) and they were divided into Group 1 (CCTA with calcium scoring), Group 2 (CCTA without calcium scoring) and Group 3 (only calcium scoring), where the association between gender, heart rate, tube voltage protocol and body mass index (BMI) were analysed. Examinations were performed using a retrospective ECG-gated CCTA protocol and the effective doses were calculated from the dose length product with a conversion coefficient of 0.026 mSv.mGy-1cm-1. No significant differences were observed in the mean effective dose between gender in all groups. The mean estimated dose was significantly higher when the heart rate was lower in Group 1 (p < 0.001) and Group 2 (p = 0.002). There were also significant differences between the mean effective dose in tube voltage protocol and BMI among the three groups. The mean effective dose was positively correlated with BMI (p < 0.001), but inversely related to the heart rate. This study supported the theory that a high heart rate, low tube voltage and low BMI could significantly reduce radiation dose exposure.
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De Roo B, Stichelbaut N, Hoste P, Verstraete K, Bacher K. The effective and collective dose to patients undergoing abdominopelvic and trunk computed tomography examinations: A Belgian multicentre study. Eur J Radiol 2019; 111:81-87. [DOI: 10.1016/j.ejrad.2018.12.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 12/18/2018] [Accepted: 12/23/2018] [Indexed: 10/27/2022]
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Isa INC, Rahmat SMS, Dom SM, Kayun Z, Karim MKA. The effects of mis-centering on radiation dose during CT head examination: A phantom study. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2019; 27:631-639. [PMID: 31205011 DOI: 10.3233/xst-190491] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
There are several factors that may contribute to the increase in radiation dose of CT including the use of unoptimized protocols and improper scanning technique. In this study, we aim to determine significant impact on radiation dose as a result of mis-centering during CT head examination. The scanning was performed by using Toshiba Aquilion 64 slices multi-detector CT (MDCT) scanner and dose were measured by using calibrated ionization chamber. Two scanning protocols of routine CT head; 120 kVp/ 180 mAs and 100 kVp/ 142 mAs were used represent standard and low dose, respectively. As reference measurement, the dose was first measured on standard cylindrical polymethyl methacrylate (PMMA) phantom that positioned at 104 cm from the floor (reference isocenter). The positions then were varied to simulate mis-centering by 5 cm from isocenter, superiorly and inferiorly at 109 cm, 114 cm, 119 cm, 124 cm and 99 cm, 94 cm, 89 cm, 84 cm, respectively. Scanning parameter and dose information from the console were recorded for the radiation effective dose (E) measurement. The highest mean CTDIvol value for MCS and MCI were 105.06 mGy (at +10 cm) and 105.51 mGy (at - 10 cm), respectively which differed significantly (p < 0.05) as compared to the isocenter. There were large significant different (p < 0.05) of mean Dose Length Product (DLP) recorded between isocenter to the MCS (85.8 mGy.cm) and MCI (93.1 mGy.cm). As the low dose protocol implemented, the volume CTDI (CTDIvol) were significantly increase (p < 0.05) for MCS (at +10 cm) and MCI (at - 10 cm) when compared to the isocenter. The phantom study revealed a noticeable different in radiation dose between isocenter and experimental groups due to degradation of the bowtie filter performance. It is anticipated that these noteworthy findings may emphasize the importance of accurate patient centering at the isocenter of CT gantry, so that CT optimization practice can be achieved.
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Affiliation(s)
- I N C Isa
- Diagnostic Imaging & Radiotherapy Program, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - S M S Rahmat
- Department of Radiology, National Cancer Institute, Putrajaya, Malaysia
- Faculty of Health Sciences, Universiti Teknologi MARA, Puncak Alam, Selangor, Malaysia
| | - S M Dom
- Faculty of Health Sciences, Universiti Teknologi MARA, Puncak Alam, Selangor, Malaysia
| | - Z Kayun
- Department of Physics, Faculty of Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - M K A Karim
- Department of Physics, Faculty of Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
- Center for Diagnostic Nuclear Imaging, Faculty of Medicine, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
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Karim MKA, Rahim NA, Matsubara K, Hashim S, Mhareb MHA, Musa Y. The effectiveness of bismuth breast shielding with protocol optimization in CT Thorax examination. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2019; 27:139-147. [PMID: 30584178 DOI: 10.3233/xst-180397] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
BACKGROUND Numerous techniques had been proposed to reduce radiation exposure in computed tomography (CT) including the use of radiation shielding. OBJECTIVE This study aims to evaluate efficacy of using a bismuth breast shield and optimized scanning parameter to reduce breast absorbed doses from CT thorax examination. METHODS Five protocols comprising the standard CT thorax clinical protocol (CP1) and four modified protocols (CP2 to CP5) were applied in anthropomorphic phantom scans. The phantom was configured as a female by placing a breast component on the chest. The breast component was divided into four quadrants, where 2 thermoluminescence dosimeters (TLD-100) were inserted into each quadrant to measure the absorbed dose. The bismuth shield was placed over the breast component during CP4 and CP5 scans. RESULTS The pattern of absorbed doses in each breast and quadrant were approximately the same for all protocols, where the 4th quadrant > 3rd quadrant > 2nd quadrant > 1st quadrant. The mean absorbed dose value in CP3 was reduced to almost 34% of CP1's mean absorbed dose. It was reduced even lower to 15% of CP1's mean absorbed dose when the breast shield was used in CP5. CONCLUSION This study showed that CT radiation exposure on the breast could be reduced by using a bismuth shield and low tube potential protocol without compromising the image quality.
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Affiliation(s)
- M K A Karim
- Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - N A Rahim
- Department of Radiology, National Cancer Institute, Precint 7, 62250 Putrajaya, Malaysia
| | - K Matsubara
- Department of Quantum Medical Technology, Faculty of Health Sciences, Kanazawa University, Japan
| | - S Hashim
- Department of Physics, Faculty of Science, Universiti Teknologi Malaysia Johor Baru, Malaysia
| | - M H A Mhareb
- Department of Physics, College of Science, Imam Abdurrahman Bin Faisal University, Saudi Arabia, City Dammam, Saudi Arabia
| | - Y Musa
- Department of Physics, Faculty of Science, Universiti Teknologi Malaysia Johor Baru, Malaysia
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Gharbi S, Labidi S, Mars M, Chelli M, Meftah S, Ladeb MF. Assessment of organ dose and image quality in head and chest CT examinations: a phantom study. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2018; 38:807-818. [PMID: 29869615 DOI: 10.1088/1361-6498/aac336] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The purpose of this study is to assess dose for radiosensitive organs and image quality in head and chest computed tomography (CT) examinations. Our focus was in the brain, eye lens and lung organs using two protocols; one protocol with fixed mAs and filtered back projection (FBP) and another with tube current modulation (TCM) and sinogram affirmed iterative reconstruction (SAFIRE). Measurements were performed on a 128-slice CT scanner by placing thermoluminescent dosimeters (TLDs) in an anthropomorphic adult phantom. Results were compared to a CT-Expo software. Objective image quality was assessed in terms of signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). SPSS software was used for data analyses. Results showed that, using TCM, doses were reduced by 22.84%-25.06% for brain, by 21.82%-23.48% for eye lens and by 54%-53.22% for lung with TLD and CT-Expo respectively. The increased SNR and CNR values achieved for scans performed with TCM combined with iterative reconstruction techniques were 38.68%-58.81% and 38.91%-43.60% respectively. We conclude that, using TCM, a significant mean organ dose reduction is achieved for brain, eye lens and lung organs. Then, combined with iterative reconstruction, image quality was well maintained in terms of SNR and CNR. Thus it is highly recommended in clinical practice optimization in head and chest CT examinations.
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Affiliation(s)
- S Gharbi
- Université Tunis EL Manar, Institut Supérieur des Technologies Médicales de Tunis, Laboratoire de recherche de Biophysique et de Technologies Médicales, 9, Avenue du Docteur Z. Essafi, Tunis 1006, Tunisia
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