1
|
Alzyoud K, Al-Murshedi S, England A. Effective dose and image quality for different patient sizes during AP upper abdominal radiography: A phantom study. Appl Radiat Isot 2023; 202:111060. [PMID: 37806283 DOI: 10.1016/j.apradiso.2023.111060] [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: 05/14/2023] [Revised: 09/17/2023] [Accepted: 09/28/2023] [Indexed: 10/10/2023]
Abstract
INTRODUCTION Undertaking medical imaging examinations on obese patients can present practical challenges. Choosing optimal imaging protocols can be difficult, especially when promoting the ALARA principle. The aim of this study was to assess the effects of increasing body part thickness on image quality (IQ) and effective dose (ED) during upper abdominal radiography. A secondary aim was to determine the optimum exposure settings for larger sized patients. METHODS Underweight, standard, overweight and obese abdomen sizes were simulated using an anthropomorphic upper abdomen phantom, without and with additional fat layers (6, 10 and 16 cm). Phantoms were imaged using a variety of tube potentials (70-110 kVp), automatic exposure control (AEC) and a source-to-image distance of 120 cm. IQ was assessed visually using a relative visual grading analysis (VGA) method. Radiation dose was evaluated by calculating the ED using the Monte Carlo PCXMC 2.0 computer program. RESULTS IQ values showed a statistical reduction (p = 0.006) with increasing phantom size across all examined tube potentials. The highest IQ scores (3.3, 2.8, 2.5 and 2.2, respectively) were obtained at 70/75 kVp for all phantom thicknesses. As tube potential increased the IQ was also shown to decrease. ED showed a statistically significant increase (p < 0.001) with increasing phantom thicknesses. CONCLUSION Higher EDs were evident when applying lower tube potentials. Using an AEC with high tube potentials (105/110 kVp) can lead to a considerable decrease in ED with acceptable IQ when undertaking upper abdomen radiography on patients with large body part thicknesses. IMPLICATION FOR PRACTICE Applying higher values of tube potentials for patients who have a thicker abdomen can lead to decreased ED.
Collapse
Affiliation(s)
- Kholoud Alzyoud
- Department of Medical Imaging, Faculty of Applied Health Science, The Hashemite University, P.O. Box 330127, Zarqa, 13133, Jordan.
| | - Sadeq Al-Murshedi
- AL-Zahraa University for Women, College of Health and Medical Technology, Karbala, Iraq
| | | |
Collapse
|
2
|
Lim KBL, Yeo ISX, Ng SWL, Pan WJ, Lee NKL. The machine-vision image guided surgery system reduces fluoroscopy time, ionizing radiation and intraoperative blood loss in posterior spinal fusion for scoliosis. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2023; 32:3987-3995. [PMID: 37428212 DOI: 10.1007/s00586-023-07848-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 06/10/2023] [Accepted: 06/27/2023] [Indexed: 07/11/2023]
Abstract
PURPOSE To determine if the novel 3D Machine-Vision Image Guided Surgery (MvIGS) (FLASH™) system can reduce intraoperative radiation exposure, while improving surgical outcomes when compared to 2D fluoroscopic navigation. METHODS Clinical and radiographic records of 128 patients (≤ 18 years of age) who underwent posterior spinal fusion (PSF), utilising either MvIGS or 2D fluoroscopy, for severe idiopathic scoliosis were retrospectively reviewed. Operative time was analysed using the cumulative sum (CUSUM) method to evaluate the learning curve for MvIGS. RESULTS Between 2017 and 2021, 64 patients underwent PSF using pedicle screws with 2D fluoroscopy and another 64 with the MvIGS. Age, gender, BMI, and scoliosis aetiology were comparable between the two groups. The CUSUM method estimated that the MvIGS learning curve with respect to operative time was 9 cases. This curve consisted of 2 phases: Phase 1 comprises the first 9 cases and Phase 2 the remaining 55 cases. Compared to 2D fluoroscopy, MvIGS reduced intraoperative fluoroscopy time, radiation exposure, estimated blood loss and length of stay by 53%, 62% 44%, and 21% respectively. Scoliosis curve correction was 4% higher in the MvIGS group, without any increase in operative time. CONCLUSION MvIGS for screw insertion in PSF contributed to a significant reduction in intraoperative radiation exposure and fluoroscopy time, as well as blood loss and length of stay. The real-time feedback and ability to visualize the pedicle in 3D with MvIGS enabled greater curve correction without increasing the operative time.
Collapse
Affiliation(s)
- Kevin Boon Leong Lim
- Division of Surgery, KK Women's and Children's Hospital, Singapore, Singapore.
- Department of Orthopaedic Surgery, KK Women's & Children's Hospital, Singapore, Singapore.
| | - Inez Su Xian Yeo
- Division of Surgery, KK Women's and Children's Hospital, Singapore, Singapore
| | - Stacy Wei Ling Ng
- Department of Orthopaedic Surgery, KK Women's & Children's Hospital, Singapore, Singapore
| | - Woei Jack Pan
- Department of Orthopaedic Surgery, KK Women's & Children's Hospital, Singapore, Singapore
| | - Nicole Kim Luan Lee
- Division of Surgery, KK Women's and Children's Hospital, Singapore, Singapore
| |
Collapse
|
3
|
Nosrati R, Callahan MJ, Tsai A, Voss SD, Zhang D. Reconsidering pregnancy screening policies for minors: patient-specific estimate of fetus and effective dose for potentially pregnant minors undergoing optimized dose CT of the pelvis. Pediatr Radiol 2023; 53:2054-2059. [PMID: 37423916 DOI: 10.1007/s00247-023-05715-5] [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: 10/14/2022] [Revised: 06/19/2023] [Accepted: 06/27/2023] [Indexed: 07/11/2023]
Abstract
BACKGROUND Only verbal pregnancy screening is recommended for post-menarcheal females undergoing pelvic radiographs. In contrast, usually, a urine/serum pregnancy test for pelvic computed tomographic (CT) exams is required out of concern for higher radiation exposure. OBJECTIVE To estimate patient-specific fetus absorbed dose to a potentially pregnant minor from an optimized dose CT of the pelvis for femoral version and surgical planning and provide evidence that such examinations of the pelvis can be performed with only verbal pregnancy screening. METHODS AND METHODS A retrospective study was performed on 102 female patients between 12-18 years of age (15.4 ± 2.1 years) who underwent optimized dose CT of the pelvis for orthopedic evaluation of femoral version and surgical planning. Optimized CT exams were performed with weight-adjusted kVp and tube current modulation. Patient-specific dose from the optimized dose CT was calculated using the National Cancer Institute Dosimetry System for CT (NCICT) database by matching each patient to a phantom from the NCI non-reference phantom library based on patient sex, weight, and height. The calculated absorbed uterus dose was used as a surrogate for the fetus dose. Furthermore, patient-specific organ doses were used to estimate the effective dose. The strengths of the linear relationships between the dose metrics and patient characteristics were assessed using Pearson correlation coefficients through linear regression. RESULTS The mean patient-specific effective dose for an optimized dose CT of the pelvis was 0.54 ± 0.20 mSv (range: 0.15-1.22 mSv). The mean estimated absorbed uterine dose was 1.57 ± 0.67 mGy (range: 0.42-4.81 mGy). Both effective dose and estimated uterine dose correlated poorly with patient physical characteristics (R = -0.26; 95% CI: [-0.43, -0.007] for age, R = 0.03; 95% CI: [-0.17, 0.22] for weight) but correlated strongly (R = 0.79, 95% CI: [0.7, 0.85]) with CTDIvol. CONCLUSION The estimated fetus dose in case of pregnancy was significantly lower than 20 mGy for urine/serum pregnancy screening, suggesting that the pregnancy screening protocols in minors undergoing optimized dose CT require reassessment and may be safely performed by verbal attestation only.
Collapse
Affiliation(s)
- Reyhaneh Nosrati
- Department of Radiology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA, 02115, USA.
| | - Michael J Callahan
- Department of Radiology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA, 02115, USA
| | - Andy Tsai
- Department of Radiology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA, 02115, USA
| | - Stephan D Voss
- Department of Radiology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA, 02115, USA
| | - Da Zhang
- Department of Radiology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA, 02115, USA
| |
Collapse
|
4
|
Nosrati R, Zhang D, Callahan MJ, Shore BJ, Tsai A. Hip Imaging in Children With Cerebral Palsy: Estimation and Intrapatient Comparison of Patient-Specific Radiation Doses of Low-Dose CT and Radiography. Invest Radiol 2023; 58:190-198. [PMID: 36070536 DOI: 10.1097/rli.0000000000000920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Hip displacement is the second most common orthopedic problem affecting children with cerebral palsy (CP). Routine radiographic hip surveillance typically involves an anteroposterior (AP) pelvis radiograph. Unfortunately, this imaging protocol is limited by its projectional technique and the positioning challenges in children with CP. Alternatively, hip low-dose computed tomography (LDCT) has been advocated as a more accurate strategy for imaging surveillance as it provides biofidelic details of the hip that is independent of patient positioning. However, the tradeoff is the (presumed) higher radiation dose to the patient. The goal of this study is to estimate patient-specific radiation doses of hip LDCTs and AP pelvis radiographs in CP patients, and perform an intrapatient dose comparison. MATERIALS AND METHODS A search of our imaging database was performed to identify children with CP who underwent hip LDCT and AP pelvis radiograph within 6 months of each other. The LDCTs were performed using weight-adjusted kVp and tube current modulation, whereas the radiographs were obtained with age-/size-adjusted kVp/mAs. The patient-specific organ and effective doses for LDCT were estimated by matching the patients to a nonreference pediatric phantom library from the National Cancer Institute Dosimetry System for Computed Tomography database with Monte Carlo-based dosimetry. The patient-specific organ and effective doses for radiograph were estimated using the National Cancer Institute Dosimetry System for Radiography and Fluoroscopy with Monte Carlo-based dose calculation. Dose conversion k-factors of dose area product for radiography and dose length product for LDCT were adapted, and the estimation results were compared with patient-specific dosimetry. RESULTS Our study cohort consisted of 70 paired imaging studies from 67 children (age, 9.1 ± 3.3 years). The patient-specific and dose length product-based effective doses for LDCT were 0.42 ± 0.21 mSv and 0.59 ± 0.28 mSv, respectively. The patient-specific and dose area product-based effective doses for radiography were 0.14 ± 0.09 mSv and 0.08 ± 0.06 mSv, respectively. CONCLUSIONS The radiation dose for a hip LDCT is ~4 times higher than pelvis radiograph, but it is still very low and poses minimal risk to the patient.
Collapse
Affiliation(s)
| | - Da Zhang
- From the Departments of Radiology
| | | | - Benjamin J Shore
- Orthopedics, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | | |
Collapse
|
5
|
Modarai B, Haulon S, Ainsbury E, Böckler D, Vano-Carruana E, Dawson J, Farber M, Van Herzeele I, Hertault A, van Herwaarden J, Patel A, Wanhainen A, Weiss S, Esvs Guidelines Committee, Bastos Gonçalves F, Björck M, Chakfé N, de Borst GJ, Coscas R, Dias NV, Dick F, Hinchliffe RJ, Kakkos SK, Koncar IB, Kolh P, Lindholt JS, Trimarchi S, Tulamo R, Twine CP, Vermassen F, Document Reviewers, Bacher K, Brountzos E, Fanelli F, Fidalgo Domingos LA, Gargiulo M, Mani K, Mastracci TM, Maurel B, Morgan RA, Schneider P. Editor's Choice - European Society for Vascular Surgery (ESVS) 2023 Clinical Practice Guidelines on Radiation Safety. Eur J Vasc Endovasc Surg 2023; 65:171-222. [PMID: 36130680 DOI: 10.1016/j.ejvs.2022.09.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 09/15/2022] [Indexed: 01/24/2023]
|
6
|
Masjedi H, Dalvand S, Zamani H, Zare MH, Zarei M. Estimating the entrance surface air kerma and diagnostic reference level in routine radiography examinations: A multi-center study. Radiat Phys Chem Oxf Engl 1993 2023. [DOI: 10.1016/j.radphyschem.2022.110593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
|
7
|
Dose Reduction and Image Quality Optimization of Pediatric Chest Radiography Using a Tungsten Filter. Bioengineering (Basel) 2022; 9:bioengineering9100583. [PMID: 36290551 PMCID: PMC9598093 DOI: 10.3390/bioengineering9100583] [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: 08/30/2022] [Revised: 10/19/2022] [Accepted: 10/19/2022] [Indexed: 11/23/2022] Open
Abstract
The use of diagnostic radiology in pediatric patients has increased, and various positive effects have been reported, including methods to reduce radiation doses in children. Research has been conducted to preserve image quality while reducing exposure and doses in pediatric patients. This study aimed to measure four different filters to identify an optimized filter for pediatric patients. The experiment was conducted using four types of filters, including aluminum, copper, molybdenum, and tungsten. The optimal filter thickness was verified using a histogram to visually evaluate the spectrum by filter thickness, effective dose on a pediatric phantom, entrance skin dose, organ absorbed dose using the PC-based Monte Carlo (PCXMC) program version 2.0 simulation, figure of merit (FOM), and image quality. As a result of measuring the spectrum according to the tube voltage and the four types of filters, dose reduction and contrast improvement effects were obtained with a 0.05 mm tungsten filter. Additionally, effective entrance skin and organ absorbed dose decreased with the said filter. The aluminum, copper, and molybdenum filters demonstrated that the effective dose scarcely decreased even when the thickness was increased; meanwhile, the effective dose decreased when the tungsten filter was 0.05 mm. The FOM with a 0.05 mm tungsten increased by 91% in the lung field and 39% in the mediastinal field. The entrance skin and organ absorbed dose in pediatric patients can be reduced by removing low-energy photons that fail in image formation using a tungsten filter.
Collapse
|
8
|
Hamzian N, Roozmand Z, Abrisham SMJ, Abdollahi-Dehkordi S, Afereydoon S, Ghorbani M, Deevband MR. Monte Carlo evaluation of effective dose and risk of exposure induced cancer death (REID) for common examinations in stereo radiography (EOS) imaging: Considering age and gender. J Med Imaging Radiat Sci 2022; 53:283-290. [DOI: 10.1016/j.jmir.2022.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 02/26/2022] [Accepted: 03/04/2022] [Indexed: 11/25/2022]
|
9
|
Hwang JH, Kim SB, Choi MK, Lee KB, Park CK. Clinical application of the optimized X-ray parameter model through analysis of disease risk and image quality when combining the ion chamber of automatic exposure control of digital radiography. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2022; 30:1099-1114. [PMID: 36120755 DOI: 10.3233/xst-221254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
OBJECTIVE To present an optimized examination model by analyzing the risk of disease and image quality according to the combination of the ion chamber of automatic exposure control (AEC) with digital radiography (DR). METHODS The X-ray quality was analyzed by first calculating the percentage average error (PAE) of DR. After that, when using AEC, the combination of the ion chambers was the same as the left and centre and right, right and centre, left and centre, centre, right, and left, for a total of six. Accordingly, the entrance surface dose (ESD), risk of disease, and image quality were evaluated. ESD was obtained by attaching a semiconductor dosimeter to the L4 level of the lumbar spine, and then irradiating X-rays to dosimeter centre through average and standard deviation of radiation dose. The calculated ESD was input into the PCXMC 2.0 programme to evaluate disease risk caused by radiation. Meanwhile, image quality according to chamber combination was quantified as the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) through Image J. RESULTS X-ray quality of DR used in the experiment was within the normal range of±10. ESD of six ion chamber combinations was 1.363mGy, 0.964mGy, 0.946mGy, 0.866mGy, 0.748mGy, 0.726mGy for lumbar anteroposterior (AP), and the lumbar lateral values were 1.126mGy, 0.209mGy, 0.830mGy, 0.662mGy, 0.111mGy, and 0.250mGy, respectively. Meanwhile, disease risk analyzed through PCXMC 2.0 was bone marrow, colon, liver, lung, stomach, urinary and other tissue cancer, and disease risk showed a tendency to increase in proportion to ESD. SNR and CNR recorded the lowest values when three chambers were combined and did not show proportionality with dose, while showed the highest values when two chambers were combined. CONCLUSION In this study, combination of three ion chambers showed the highest disease risk and lowest image quality. Using one ion chamber showed the lowest disease risk, but lower image quality than two ion chambers. Therefore, if considering all above factors, combination of two ion chambers can optimally maintain the disease risk and image quality. Thus, it is considered an optimal X-ray examination parameter.
Collapse
Affiliation(s)
- Jun-Ho Hwang
- Department of Neurosurgery, Kyung Hee University Medical Center, Seoul, Korea
| | - Sung-Bum Kim
- Department of Neurosurgery, Kyung Hee University Medical Center, Seoul, Korea
- Department of Neurosurgery, Kyung Hee University College of Medicine, Seoul, Korea
| | - Man-Kyu Choi
- Department of Neurosurgery, Kyung Hee University Medical Center, Seoul, Korea
- Department of Neurosurgery, Kyung Hee University College of Medicine, Seoul, Korea
| | - Kyung-Bae Lee
- Department of Radiology, Kyung Hee University Medical Center, Seoul, Korea
| | - Chang-Kyu Park
- Department of Neurosurgery, Kyung Hee University Medical Center, Seoul, Korea
- Department of Neurosurgery, Kyung Hee University College of Medicine, Seoul, Korea
| |
Collapse
|
10
|
Visual Evaluation of Image Quality of a Low Dose 2D/3D Slot Scanner Imaging System Compared to Two Conventional Digital Radiography X-ray Imaging Systems. Diagnostics (Basel) 2021; 11:diagnostics11101932. [PMID: 34679630 PMCID: PMC8534907 DOI: 10.3390/diagnostics11101932] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/13/2021] [Accepted: 10/15/2021] [Indexed: 11/23/2022] Open
Abstract
The purpose of this study was to assess the image quality of the low dose 2D/3D slot scanner (LDSS) imaging system compared to conventional digital radiography (DR) imaging systems. Visual image quality was assessed using the visual grading analysis (VGA) method. This method is a subjective approach that uses a human observer to evaluate and optimise radiographic images for different imaging technologies. Methods and materials: ten posterior-anterior (PA) and ten lateral (LAT) images of a chest anthropomorphic phantoms and a knee phantom were acquired by an LDSS imaging system and two conventional DR imaging systems. The images were shown in random order to three (chest) radiologists and three experienced (knee) radiographers, who scored the images against a number of criteria. Inter- and intraobserver agreement was assessed using Fleiss’ kappa and weighted kappa. Results: the statistical comparison of the agreement between the observers showed good interobserver agreement, with Fleiss’ kappa coefficients of 0.27–0.63 and 0.23–0.45 for the chest and knee protocols, respectively. Comparison of intraobserver agreement also showed good agreement with weighted kappa coefficients of 0.27–0.63 and 0.23–0.45 for the chest and knee protocols, respectively. The LDSS imaging system achieved significantly higher VGA image quality compared to the DR imaging systems in the AP and LAT chest protocols (p < 0.001). However, the LDSS imaging system achieved lower image quality than one DR system (p ≤ 0.016) and equivalent image quality to the other DR systems (p ≤ 0.27) in the knee protocol. The LDSS imaging system achieved effective dose savings of 33–52% for the chest protocol and 30–35% for the knee protocol compared with DR systems. Conclusions: this work has shown that the LDSS imaging system has the potential to acquire chest and knee images at diagnostic quality and at a lower effective dose than DR systems.
Collapse
|
11
|
Konst B, Nøtthellen J, Bilet E, Båth M. Radiographic and fluoroscopic X-ray systems: Quality control of the X-ray tube and automatic exposure control using theoretical spectra to determine air kerma and dose to a homogenous phantom. J Appl Clin Med Phys 2021; 22:204-218. [PMID: 34196461 PMCID: PMC8364276 DOI: 10.1002/acm2.13329] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 04/26/2021] [Accepted: 05/26/2021] [Indexed: 12/26/2022] Open
Abstract
PURPOSE To develop a method to perform quality control (QC) of X-ray tubes and automatic exposure control (AEC) as a part of the QC of the radiographic and fluoroscopic X-ray system. Our aim is to verify the output from the X-ray tube by comparing the measured radiation output, or air kerma, to the theoretical output given the applied exposure settings and geometry, in addition to comparing the measured kV to the nominal kV. The AEC system for fluoroscopic and conventional X-ray systems is assessed by determining the absorbed dose to a homogenous phantom with different thicknesses. METHOD This study presents a model to verify the X-ray tube measurement results and a method to determine the dose to a homogenous phantom (Dphantom ). The following input is needed: a parameterized model of the X-ray spectrum, the X-ray tube measurements using a multifunctional X-ray meter, the exposure parameters recorded via imaging of polymethyl methacrylate (PMMA) slabs of different thickness that simulate the patient using AEC, and a parameterized model for calculating the dose to water from Monte Carlo simulations. The output is the entrance surface dose (ESD) and absorbed dose in the phantom, Dphantom (µGy). In addition, the parameterized X-ray spectrum is used to compare theoretical and measured air kerma as a part of the QC of the X-ray tube. To verify the proposed method, the X-ray spectrum provided in this study, SPECTRUM, was compared to two commercially available spectra, SpekCalc and Institute of Physics and Engineering in Medicine (IPEM) 78. The fraction of energy imparted to the homogenous phantom was compared to the imparted fraction calculated by PCXMC. RESULTS The spectrum provided in this study was in good agreement with two previously published X-ray spectra. The absolute percentage differences of the spectra varied from 0.05% to 3.9%, with an average of 1.4%, compared to SpekCalc. Similarly, the deviation from IPEM report 78 varied from 0.02% to 2.3%, with an average of 0.74%. The SPECTRUM was parameterized for calculation of the imparted fraction for target angles of 10°, 12°, and 15°, kV (50-150 kV) with the materials Al (2.2-8 mm), Cu (0-1 mm), and any combination of the filters, PMMA and water. The deviation of energy imparted from the results by PCXMC was less than 8% for all measurements across different kV, filtration, and vendors, obtained by using PMMA to record the exposure parameters, while the dose was calculated based on water with same thicknesses as the PMMA. CONCLUSION This study presents an accurate and suitable method to perform a part of the QC of fluoroscopic and conventional X-ray systems with respect to the X-ray tube and the associated AEC system. The method is suitable for comparing protocols within and between systems via the absorbed dose.
Collapse
Affiliation(s)
- Bente Konst
- Department of RadiologyVestfold Hospital TrustTønsbergNorway
- Faculty of Mathematics and Natural SciencesDepartment of PhysicsUniversity of OsloOsloNorway
| | - Jacob Nøtthellen
- Division of Diagnostics and InterventionOslo University HospitalOsloNorway
| | - Ellinor Bilet
- Norwegian Hospital Construction AgencyTrondheimNorway
| | - Magnus Båth
- Department of Medical Physics and Biomedical EngineeringSahlgrenska University HospitalGothenburgSweden
- Department of Radiation PhysicsInstitute of Clinical SciencesSahlgrenska Academy at University of GothenburgGothenburgSweden
| |
Collapse
|
12
|
Rousseau J, Dreuil S, Bassinet C, Cao S, Elleaume H. Surgivisio® and O-arm®O2 cone beam CT mobile systems for guidance of lumbar spine surgery: Comparison of patient radiation dose. Phys Med 2021; 85:192-199. [PMID: 34111631 DOI: 10.1016/j.ejmp.2021.04.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 04/14/2021] [Accepted: 04/19/2021] [Indexed: 10/21/2022] Open
Abstract
PURPOSE To compare patient radiation doses in cone beam computed tomography (CBCT) of two mobile systems used for navigation-assisted mini-invasive orthopedic surgery: O-arm®O2 and Surgivisio®. METHODS The study focused on imaging of the spine. Thermoluminescent dosimeters were used to measure organs and effective doses (ED) during CBCT. An ionization-chamber and a solid-state sensor were used to measure the incident air-kerma (Ki) at the center of the CBCT field-of-view and Ki during 2D-imaging, respectively. The PCXMC software was used to calculate patient ED in 2D and CBCT configurations. The image quality in CBCT was evaluated with the CATPHAN phantom. RESULTS The experimental ED estimate for the low-dose 3D-modes was 2.41 and 0.35 mSv with O-arm®O2 (Low Dose 3D-small-abdomen) and Surgivisio® (3DSU-91 images), respectively. PCXMC results were consistent: 1.54 and 0.30 mSv. Organ doses were 5 to 12 times lower with Surgivisio®. Ki at patient skin were comparable on lateral 2D-imaging (0.5 mGy), but lower with O-arm®O2 on anteroposterior (0.3 versus 0.9 mGy). Both systems show poor low contrast resolution and similar high contrast spatial resolution (7 line-pairs/cm). CONCLUSIONS This study is the first to evaluate patient ED and organ doses with Surgivisio®. A significant difference in organs doses was observed between the CBCT systems. The study demonstrates that Surgivisio® used on spine delivers approximately five to six times less patient ED, compared to O-arm®O2, in low dose 3D-modes. Doses in 2D-mode preceding CBCT were higher with Surgivisio®, but negligible compared to CBCT doses under the experimental conditions tested.
Collapse
Affiliation(s)
- Julia Rousseau
- Pôle Imagerie, CHU Grenoble Alpes, Avenue Maquis du Grésivaudan, 38700 La Tronche, France.
| | - Serge Dreuil
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), 31 Avenue de la Division Leclerc, 92260 Fontenay-aux-Roses, France.
| | - Céline Bassinet
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), 31 Avenue de la Division Leclerc, 92260 Fontenay-aux-Roses, France.
| | - Sophie Cao
- Pôle Coordination des Gestes Chirurgicaux et Interventionnels, CHU Grenoble Alpes, Avenue Maquis du Grésivaudan, 38700 La Tronche, France.
| | - Hélène Elleaume
- INSERM UA07 Team STROBE, ESRF 71 Avenue des Martyrs, 38000 Grenoble, France.
| |
Collapse
|
13
|
Fum WKS, Wong JHD, Tan LK. Monte Carlo-based patient internal dosimetry in fluoroscopy-guided interventional procedures: A review. Phys Med 2021; 84:228-240. [PMID: 33849785 DOI: 10.1016/j.ejmp.2021.03.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 02/18/2021] [Accepted: 03/03/2021] [Indexed: 11/27/2022] Open
Abstract
PURPOSE This systematic review aims to understand the dose estimation approaches and their major challenges. Specifically, we focused on state-of-the-art Monte Carlo (MC) methods in fluoroscopy-guided interventional procedures. METHODS All relevant studies were identified through keyword searches in electronic databases from inception until September 2020. The searched publications were reviewed, categorised and analysed based on their respective methodology. RESULTS Hundred and one publications were identified which utilised existing MC-based applications/programs or customised MC simulations. Two outstanding challenges were identified that contribute to uncertainties in the virtual simulation reconstruction. The first challenge involves the use of anatomical models to represent individuals. Currently, phantom libraries best balance the needs of clinical practicality with those of specificity. However, mismatches of anatomical variations including body size and organ shape can create significant discrepancies in dose estimations. The second challenge is that the exact positioning of the patient relative to the beam is generally unknown. Most dose prediction models assume the patient is located centrally on the examination couch, which can lead to significant errors. CONCLUSION The continuing rise of computing power suggests a near future where MC methods become practical for routine clinical dosimetry. Dynamic, deformable phantoms help to improve patient specificity, but at present are only limited to adjustment of gross body volume. Dynamic internal organ displacement or reshaping is likely the next logical frontier. Image-based alignment is probably the most promising solution to enable this, but it must be automated to be clinically practical.
Collapse
Affiliation(s)
- Wilbur K S Fum
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; Division of Radiological Sciences, Singapore General Hospital, Outram Rd, Singapore 169608, Singapore.
| | - Jeannie Hsiu Ding Wong
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Li Kuo Tan
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
| |
Collapse
|
14
|
Tzanis E, Perisinakis K, Ioannou CV, Tsetis D, Damilakis J. A novel personalized dosimetry method for endovascular aneurysm repair (EVAR) procedures. Eur Radiol 2021; 31:6547-6554. [PMID: 33675386 DOI: 10.1007/s00330-021-07789-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/20/2021] [Accepted: 02/15/2021] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To estimate radiation doses for the primarily irradiated organs/tissues of patients subjected to standard endovascular aneurysm repair (EVAR) procedures using a novel personalized dosimetry method. METHODS Dosimetric and anthropometric data were collected prospectively for eight patients who underwent standard EVAR procedures. Patient-specific Monte Carlo simulations were performed to estimate organ/tissue doses from each of the fluoroscopic and digital subtraction angiography acquisitions involved in EVAR. Individual-specific cumulative absorbed doses were estimated for the skin, spinal bone marrow, heart, kidneys, liver, colon, bladder, pancreas, stomach, and spleen and compared to corresponding values estimated through a commercially available dosimetric software package that employs standardized phantoms. RESULTS The highest organ/tissue radiation doses from EVAR were found for the skin, spinal bone marrow, kidneys, and spleen as 192.4 mGy, 96.7 mGy, 72.9 mGy, and 33.6 mGy respectively, while the doses to the heart, liver, colon, bladder, pancreas, and stomach were 6.3 mGy, 14.4 mGy, 18.4 mGy, 14.8 mGy, 21.6 mGy, and 11.2 mGy respectively. Corresponding dose values using standardized phantoms were found to differ up to 151%. CONCLUSION Considerable radiation doses may be received by primarily exposed organs/tissues during standard EVAR. The specific size/anatomy of the patient and the variation in exposure parameters/beam angulation between different projections commonly involved in EVAR procedures should be taken into account if reliable organ dose data are to be derived. KEY POINTS • A novel patient-specific dosimetry method was utilized to estimate radiation doses to the primarily irradiated organs/tissues of patients subjected to standard endovascular aneurysm repair procedures. • The use of standardized mathematical anthropomorphic phantoms to derive organ dose from fluoroscopically guided procedures may result in considerable inaccuracies due to differences in the assumed organ position/volume/shape compared to patients.
Collapse
Affiliation(s)
- Eleftherios Tzanis
- Department of Medical Physics, Medical School, University of Crete, P.O. Box 2208, Heraklion, 71003, Crete, Greece
| | - Kostas Perisinakis
- Department of Medical Physics, University Hospital of Heraklion, Medical School, University of Crete, Crete, Greece
| | - Christos V Ioannou
- Department of Cardiothoracic and Vascular Surgery, Vascular Surgery Unit, University Hospital of Heraklion, Medical School, University of Crete, Crete, Greece
| | - Dimitrios Tsetis
- Department of Radiology, Interventional Radiology Unit, University Hospital of Heraklion, Medical School, University of Crete, Crete, Greece
| | - John Damilakis
- Department of Medical Physics, University Hospital of Heraklion, Medical School, University of Crete, Crete, Greece.
| |
Collapse
|
15
|
D'Alessio A, Cannillo B, Guzzardi G, Cernigliaro M, Carriero A, Brambilla M. Conversion factors for effective dose and organ doses with the air Kerma area product in hysterosalpingography. Phys Med 2020; 81:40-46. [PMID: 33373780 DOI: 10.1016/j.ejmp.2020.11.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 11/20/2020] [Accepted: 11/26/2020] [Indexed: 11/30/2022] Open
Abstract
Histerosalpingography (HSG) remains the dominant diagnostic tool for investigation of infertility in women. Conversion factors used to estimate effective (E) and organ doses (HT) from air Kerma area product (KAP) are needed to estimate patient doses in HSG, performed with state-of-the-art fluoroscopic X-ray systems with digital detectors. In this study, estimates of E and HT for six critical organs/tissues, were derived on an individual basis in 120 HSG procedures and in 1410 irradiation events, performed on two X-ray systems from information available through the radiation dose structured report using Monte Carlo methods. Mean values of E and Hovaries were1.0 ± 0.9 mSv and 5.6 ± 5.4 mGy. E/KAP conversion factors of 0.13; 0.18; 0.28 and 0.35 mSv Gy-1cm-2 were established for irradiation events with a Cu filtration of 0.0; 0.1; 0.4 and 0.9 mm. A high agreement was obtained between E estimated through Monte Carlo methods and E/KAP conversion factors accounting separately for the different modes of fluoroscopy and the radiography component of HSG, with a systematic error of 0 mSv and lower/upper limits of agreement of -0.6 and 0.5 mSv. On the contrary, the use of a single coefficient of conversion did not provide accurate estimates of E, showing a bias of -0.4 mSv and lower and upper limits of agreement of -1.9 and 1.2 mSv. An algorithm for the estimation of effective and organ doses from KAP has been established in HSG procedures depending on the Cu filtration in the X-ray irradiation events.
Collapse
Affiliation(s)
- Andrea D'Alessio
- Medical Physics Department, University Hospital "Maggiore della Carità", Novara, Italy
| | - Barbara Cannillo
- Medical Physics Department, University Hospital "Maggiore della Carità", Novara, Italy
| | - Giuseppe Guzzardi
- Radiology Department, University Hospital "Maggiore della Carità", Novara, Italy
| | | | - Alessandro Carriero
- Radiology Department, University Hospital "Maggiore della Carità", Novara, Italy
| | - Marco Brambilla
- Medical Physics Department, University Hospital "Maggiore della Carità", Novara, Italy.
| |
Collapse
|
16
|
Harbron RW, Abdelhalim M, Ainsbury EA, Eakins JS, Alam A, Lee C, Modarai B. Patient radiation dose from x-ray guided endovascular aneurysm repair: a Monte Carlo approach using voxel phantoms and detailed exposure information. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2020; 40:704-726. [PMID: 32428884 DOI: 10.1088/1361-6498/ab944e] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Endovascular aneurysm repair (EVAR) is a well-established minimally invasive technique that relies on x-ray guidance to introduce a stent through the femoral artery and manipulate it into place. The aim of this study was to estimate patient organ and effective doses from EVAR procedures using anatomically realistic computational phantoms and detailed exposure information from radiation dose structured reports (RDSR). Methods: Lookup tables of conversion factors relating kerma area product (PKA) to organ doses for 49 different beam angles were produced using Monte Carlo simulations (MCNPX2.7) with International Commission on Radiological Protection (ICRP) adult male and female voxel phantoms for EVAR procedures of varying complexity (infra-renal, fenestrated/branched and thoracic EVAR). Beam angle specific correction factors were calculated to adjust doses according to x-ray energy. A MATLAB function was written to find the appropriate conversion factor in the lookup table for each exposure described in the RDSR, perform energy corrections and multiply by the respective exposure PKA. Using this approach, organ doses were estimated for 183 EVAR procedures in which RDSRs were available. A number of simplified dose estimation methodologies were also investigated for situations in which RDSR data are not available. Results: Mean estimated bone marrow doses were 57 (range: 2-247), 86 (2-328) and 54 (8-250) mGy for infra-renal, fenestrated/branched and thoracic EVAR, respectively. Respective effective doses were 27 (1-208), 54 (1-180) and 37 (5-167) mSv. Dose estimates using non-individualised, average conversion factors, along with those produced using the alternative Monte Carlo code PCXMC, yielded reasonably similar results overall, though variation for individual procedures could exceed 100% for some organs. In conclusion, radiation doses from x-ray guided endovascular aneurysm repairs are potentially high, though this must be placed in the context of the life sparing nature and high success rate for this procedure.
Collapse
Affiliation(s)
- Richard W Harbron
- Population Health Sciences Institute, Newcastle University, Royal Victoria Infirmary, Queen Victoria Road, Newcastle-upon-Tyne NE1 4LP, United Kingdom. NIHR Health Protection Research Unit in Chemical and Radiation Threats and Hazards, Newcastle University, Newcastle-upon-Tyne United Kingdom
| | | | | | | | | | | | | |
Collapse
|
17
|
Karambatsakidou A, Steiner K, Fransson A, Poludniowski G. Age-specific and gender-specific radiation risks in paediatric angiography and interventional cardiology: conversion coefficients and risk reference values. Br J Radiol 2020; 93:20190869. [PMID: 32242740 PMCID: PMC10993205 DOI: 10.1259/bjr.20190869] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 03/27/2020] [Accepted: 03/30/2020] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To estimate risk for exposure-induced cancer death (REID), organ-specific risks of exposure-induced cancer death (REIDHT) and associated conversion coefficients (CCREID:KAP=REID/kerma-area product (KAP), CCREIDHT:KAP=REIDHT/KAP) in paediatric cardiac catheterizations using data from radiation dose structured reports (RDSR). A novel risk surveillance tool consisting of age-specific and gender-specific risk reference values (RRVs) related to population cancer risk is suggested. METHODS The PCXMC v.2.0 code is used together with exposure-related information from RDSR from a cohort of 238 children to assess cancer risks and related conversion coefficients. The KAP corresponding to 1 in 1000 of increased REID is used to define age-specific and gender-specific KAP values to monitor risk in such patient cohorts, here denoted as RRVs. RESULTS The REID estimates ranged from below 1 up to 300 in 100,000, and the RRVs for the different age groups and gender ranged from 0.77 Gycm2 and 2.1 Gycm2 for neonates (female, male) to 11 Gycm2 and 25 Gycm2 for 15-year-olds (female, male). The CCREID:KAP and CCREIDHT:KAP decreased biexponentially with increased age, being notably higher for female patients. CONCLUSIONS Prominent risk contributing organs were the lungs and the (female) breast. The concept of age-specific and gender-specific RRVs related to population cancer risk is introduced and is intended to be used as a supporting tool for physicians performing such interventions. ADVANCES IN KNOWLEDGE Age-related and gender-related conversion coefficients for radiation risk, CCREID:KAP and CCREIDHT:KAP, are introduced and a novel risk surveillance concept, the RRV, is suggested for paediatric cardiac catheterizations.
Collapse
Affiliation(s)
- Angeliki Karambatsakidou
- Department of Medical Radiation Physics and Nuclear Medicine,
Karolinska University Hospital, 171 76
Stockholm, Sweden
- Department of Oncology-Pathology, Karolinska
Institutet, 171 76 Stockholm,
Sweden
| | - Kristoffer Steiner
- Department of Women's and Children's Health, Karolinska
Institutet, 171 76 Stockholm,
Sweden
- Department of Paediatric Cardiology, Karolinska University
Hospital, Astrid Lindgrens Children´s Hospital
Solna, 171 76 Stockholm,
Sweden
| | - Annette Fransson
- Department of Medical Radiation Physics and Nuclear Medicine,
Karolinska University Hospital, 171 76
Stockholm, Sweden
- Department of Oncology-Pathology, Karolinska
Institutet, 171 76 Stockholm,
Sweden
| | - Gavin Poludniowski
- Department of Medical Radiation Physics and Nuclear Medicine,
Karolinska University Hospital, 171 76
Stockholm, Sweden
- Department of Oncology-Pathology, Karolinska
Institutet, 171 76 Stockholm,
Sweden
| |
Collapse
|
18
|
Santoro-Fernandes V, Santos JC, Mariano L, Vanin VR, Costa PR. Uncertainty estimation and statistical comparative methodology for mammography x-ray energy spectra. Biomed Phys Eng Express 2020; 6:035018. [PMID: 33438663 DOI: 10.1088/2057-1976/ab817d] [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
Numerical models are an alternative to measurements of x-ray energy spectra when validated by comparative methods that assess the similarity of experimental and calculated spectra. In this work, we compared x-ray energy spectra using several methodologies and determined the methodology with highest statistical power among them. Experiments and Monte Carlo (MC) simulations were used to generate a set of 65 experimental and simulated x-ray mammography spectra pairs typically used in mammography applications. They were generated using Tungsten and Molybdenum targets and Molybdenum and Rhodium filters. The x-ray beams were transmitted through breast tissue equivalent material (bTEM) plates with different glandularities and thicknesses, and the transmitted beam was detected using solid-state x-ray spectrometry with a Cadmium Telluride (CdTe) diode. The MC simulations used the PENELOPE code. Additional uncertainties, beyond that from counting, were propagated using the MC method. Quantitative comparative methods based on the [Formula: see text] statistics, the first and second half-value layers, the mean energy, the effective energy, and the non-parametric u-test were applied and their specificity (true negative rate) was assessed. The polyenergetic normalized glandular dose (DgNp) to a 6 cm breast of 50/50 glandularity was derived from the spectra. In this work, the [Formula: see text] statistics attained the highest score; therefore, it is the most indicated metric for the x-ray energy spectra comparative evaluations. The contribution of the additional uncertainties was important, being responsible for up to 98% of the spectra total uncertainty and shifting the mean of the evaluated [Formula: see text] to 1.2(1), compatible with its expected value. The use of non-parametric test is discouraged by our results, since it failed to distinguish spectra pairs that resulted in up to 72% discrepant DgNp.
Collapse
|
19
|
Borrego D, Apostoaei AI, Thomas BA, Hoffman FO, Simon SL, Zablotska LB, Lee C. Organ-specific dose coefficients derived from Monte Carlo simulations for historical (1930s to 1960s) fluoroscopic and radiographic examinations of tuberculosis patients. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2019; 39:950-965. [PMID: 31269474 DOI: 10.1088/1361-6498/ab2f10] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This work provides dose coefficients necessary to reconstruct doses used in epidemiological studies of tuberculosis patients treated from the 1930s through the 1960s, who were exposed to diagnostic imaging while undergoing treatment. We made use of averaged imaging parameters from measurement data, physician interviews, and available literature of the Canadian Fluoroscopy Cohort Study and, on occasion, from a similar study of tuberculosis patients from Massachusetts, United States, treated between 1925 and 1954. We used computational phantoms of the human anatomy and Monte Carlo radiation transport methods to compute dose coefficients that relate dose in air, at a point 20 cm away from the source, to absorbed dose in 58 organs. We selected five male and five female phantoms, based on the mean height and weight of Canadian tuberculosis patients in that era, for the 1-, 5-, 10-, 15-year old and adult ages. Using high-performance computers at the National Institutes of Health, we simulated 2,400 unique fluoroscopic and radiographic exposures by varying x-ray beam quality, field size, field shuttering, imaged anatomy, phantom orientation, and computational phantom. Compared with previous dose coefficients reported for this population, our dosimetry system uses improved anatomical phantoms constructed from computed tomography imaging datasets. The new set of dose coefficients includes tissues that were not previously assessed, in particular, for tissues outside the x-ray field or for pediatric patients. In addition, we provide dose coefficients for radiography and for fluoroscopic procedures not previously assessed in the dosimetry of this cohort (i.e. pneumoperitoneum and chest aspirations). These new dose coefficients would allow a comprehensive assessment of exposures in the cohort. In addition to providing newly derived dose coefficients, we believe the automation and methods developed to complete these dosimetry calculations are generalizable and can be applied to other epidemiological studies interested in an exposure assessment from medical x-ray imaging. These epidemiological studies provide important data for assessing health risks of radiation exposure to help inform the current system of radiological protection and efforts to optimize the use of radiation in medical studies.
Collapse
Affiliation(s)
- David Borrego
- Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Drive, Bethesda MD 20892-9778, United States of America
| | | | | | | | | | | | | |
Collapse
|
20
|
Alqahtani SJM, Welbourn R, Meakin JR, Palfrey RM, Rimes SJ, Thomson K, Knapp KM. Increased radiation dose and projected radiation-related lifetime cancer risk in patients with obesity due to projection radiography. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2019; 39:38-53. [PMID: 30569898 DOI: 10.1088/1361-6498/aaf1dd] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
PURPOSE Primarily to evaluate the radiation dose delivered to patients with obesity in projection radiography and its relationship to the patient's size. A secondary purpose is to estimate the subsequent projected radiation-related lifetime cancer risk to patients with obesity compared to normal-weight patients. METHOD AND MATERIAL Data from 1964 patients from a bariatric clinic in the UK were reviewed with the relevant permission. 630 patients were identified to have a projection radiography history and were included in the study. Patients' dose area product (DAP) data were collected for all projection radiography. Multiple exams in one day including a single DAP reading and exams with no records of DAP and exposure factors were excluded. Correlations were calculated and data analysed to yield the third quartile for each examination using STATA 14. Absorbed doses were generated from PCXMC simulation, utilising DAP data from this study and the UK national diagnostic reference level (NDRL), to calculate the effective risk for patients with obesity compared to patients with normal-weight. RESULTS Patients with obesity received higher DAPs for all examinations included in this study compared to NDRL. Abdominal and lumbar spine radiographs DAPs were the highest (17.6 and 30.31 Gy cm2) compared to the NDRL (2.5 and 4 Gy cm2). Only moderate to low correlations were found between patient's size and DAPs in the abdomen and chest radiographs. The projected radiation-related lifetime cancer risk for patients with obesity is up to 153% higher than for adult patients with normal weight. CONCLUSION Patients with obesity receive higher DAPs than normal-weight adults which may be in excess of that expected due to their size. Therefore, radiation-related lifetime cancer risk is increased in patients with obesity as a result of medical radiation exposures. This indicates more dose optimisation research is needed in this group of patients to reduce dose rate and variation.
Collapse
Affiliation(s)
- Saeed J M Alqahtani
- Medical Imaging Department, University of Exeter, Exeter EX1 2LU, United Kingdom. Diagnostic Radiology Department, Najran University, Najran, 61441, Kingdom of Saudi Arabia
| | | | | | | | | | | | | |
Collapse
|
21
|
Calculating organ and effective doses in paediatric interventional cardiac radiology based on DICOM structured reports – Is detailed examination data critical to dose estimates? Phys Med 2019; 57:17-24. [DOI: 10.1016/j.ejmp.2018.12.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 11/09/2018] [Accepted: 12/12/2018] [Indexed: 11/19/2022] Open
|
22
|
Alzyoud K, Hogg P, Snaith B, Flintham K, England A. Impact of body part thickness on AP pelvis radiographic image quality and effective dose. Radiography (Lond) 2018; 25:e11-e17. [PMID: 30599841 DOI: 10.1016/j.radi.2018.09.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 09/04/2018] [Accepted: 09/06/2018] [Indexed: 10/28/2022]
Abstract
INTRODUCTION Within medical imaging variations in patient size can generate challenges, especially when selecting appropriate acquisition parameters. This experiment sought to evaluate the impact of increasing body part thickness on image quality (IQ) and effective dose (E) and identify optimum exposure parameters. METHODS An anthropomorphic pelvis phantom was imaged with additional layers (1-15 cm) of animal fat as a proxy for increasing body thickness. Acquisitions used the automatic exposure control (AEC), 100 cm source to image distance (SID) and a range of tube potentials (70-110 kVp). IQ was evaluated physically and perceptually. E was estimated using PCXMC software. RESULTS For all tube potentials, signal to noise ratio (SNR) and contrast to noise ratio (CNR) deceased as body part thickness increased. 70 kVp produced the highest SNR (46.6-22.6); CNR (42.8-17.6). Visual grading showed that the highest IQ scores were achieved using 70 and 75 kVp. As thickness increases, E increased exponentially (r = 0.96; p < 0.001). Correlations were found between visual and physical IQ (SNR r = 0.97, p < 0.001; CNR r = 0.98, p < 0.001). CONCLUSION To achieve an optimal IQ across the range of thicknesses, lower kVp settings were most effective. This is at variance with professional practice as there is a tendency for radiographers to increase kVp as thickness increases. Dose reductions were experienced at higher kVp settings and are a valid method for optimisation when imaging larger patients.
Collapse
Affiliation(s)
- K Alzyoud
- School of Health Sciences, University of Salford, Salford M6 6PU, United Kingdom; Faculty of Allied Health Sciences, Hashemite University, Zarqa, Jordan.
| | - P Hogg
- School of Health Sciences, University of Salford, Salford M6 6PU, United Kingdom.
| | - B Snaith
- The Mid Yorkshire Hospitals NHS Trust, Wakefield WF1 4DG, United Kingdom; University of Bradford, Bradford BD7 1DP, United Kingdom.
| | - K Flintham
- The Mid Yorkshire Hospitals NHS Trust, Wakefield WF1 4DG, United Kingdom.
| | - A England
- School of Health Sciences, University of Salford, Salford M6 6PU, United Kingdom.
| |
Collapse
|