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1.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 43(3): 429-434, 2021 Jun 30.
Artigo em Chinês | MEDLINE | ID: mdl-34238420

RESUMO

Objective To design a novel automatic dispensing and injecting system of positron radiopharmaceuticals,for precise dose dispensing,simplified operation,and reduction of occupational radiation exposure. Methods The automatic dispensing and injecting system was fabricated with tungsten alloy as the shielding material.The performance and radiation protection of the device were assessed. Results The total time of injection using the automatic dispensing and injecting system was about 60 s.The ratio of successful injection in stability test was 100%.The deviation of the dispensing dose with the system was ≤3%.With the tungsten alloy shield(40 mmPb of the cabinet,60 mmPb of the countertop,15 mmPb of the protective shield,and 50 mmPb of the inbuilt jar for radiopharmaceuticals),the average dose rate at 30 cm from the device was 1.44 µSv/h,and the radiation dose at the operator's extremity was reduced by 99%. Conclusions This automatic dispensing and injecting system of positron radiopharmaceuticals is easy to operate with precise dispensing dose.It is safe and meets the requirements of radiation protection.


Assuntos
Exposição Ocupacional , Proteção Radiológica , Elétrons , Exposição Ocupacional/análise , Doses de Radiação , Compostos Radiofarmacêuticos
2.
Radiat Prot Dosimetry ; 194(2-3): 178-185, 2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34218283

RESUMO

Novel building materials were manufactured and analyzed for 226Ra, 232Th and 40K using an HPGe gamma-ray spectrometer. The results show that the highest value of 40K was 4530 Bq per kg which was measured in a sample containing fly ashes from olive stones. The highest values of 226Ra and 232Th activities were 181 and 185 Bq per kg, which were measured in a sample with fly ashes from the co-combustion of coal and coke, respectively. On the other hand, the lowest values of 40K, 226Ra and 232Th activities were obtained for samples incorporating mussel shells. The radiological health hazard parameters, such as radium equivalent activity (Raeq), activity concentration index (I), absorbed and effective dose rates, associated with these radionuclides were evaluated. These values are within the EU recommended limits in building materials, except for samples of concrete containing fly ashes from olive stones, coal and coke. This study has contributed to the inclusion of industrial wastes that have not been collected previously in the Naturally Occurring Radioactive Material (NORM) databases on radioactivity of building materials.


Assuntos
Exposição à Radiação , Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Materiais de Construção , Radioisótopos de Potássio/análise , Doses de Radiação , Rádio (Elemento)/análise , Espanha , Tório/análise
3.
Radiat Prot Dosimetry ; 194(2-3): 121-134, 2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34227656

RESUMO

This study aims to evaluate patient radiation dose during fluoroscopically guided endovascular aneurysm repair (EVAR) procedures. Fluoroscopy time (FT) and kerma-area product (KAP) were recorded from 87 patients that underwent EVAR procedures with a mobile C-arm fluoroscopy system. Effective dose (ED) and organs' doses were calculated utilising appropriate conversion coefficients based on the recorded KAP values. Entrance surface dose (ESD) was calculated based on KAP values and technical parameters. The mean FT was 22.7 min (range 6.4-76.8 min), resulting in a mean KAP of 36.6 Gy cm2 (range 2.0-167.8 Gy cm2), a mean ED of 6.2 mSv (range 0.3-28.5 mSv) and a mean ESD of 458 mGy (range 26-2098 mGy). The corresponding median values were 17.4 min, 25.6 Gy cm2, 4.4 mSv and 320 mGy. The threshold of 2 Gy for skin erythema was exceeded in two procedures for a focus-to-skin distance (FSD) of 40 cm and six procedures when an FSD of 30 cm was considered. The highest doses absorbed by the adrenals, kidneys, spleen and pancreas and ranged between 3.7 and 313.3 mGy (average 66.8 mGy), 3.3 and 285.1 mGy (average 60.8 mGy), 1.3 and 111.1 mGy (average 23.7 mGy), 1.1 and 92.1 mGy (average 19.6 mGy), respectively. A wide range of patient doses was reported in the literature. The radiation dose received by the patients was comparative or lower than most of the previously reported values. However, higher doses can be revealed due to the X-ray system's non-optimum use and extended FTs, mainly affected by complex clinical conditions, patients' body habitus and vascular surgeon experience. The large variation of patient doses highlights the potential to optimise the EVAR procedure by considering the balance between the radiation dose and the required image quality. Additional studies need to be conducted in increasing the vascular surgeons' awareness regarding patient dose and radiation protection issues during EVAR procedures.


Assuntos
Aneurisma da Aorta Abdominal , Implante de Prótese Vascular , Procedimentos Endovasculares , Proteção Radiológica , Aneurisma da Aorta Abdominal/cirurgia , Fluoroscopia , Humanos , Doses de Radiação , Radiografia Intervencionista
4.
Artigo em Japonês | MEDLINE | ID: mdl-34305057

RESUMO

The purpose of this study was to educate operators regarding cardiac catheterization using radiation protection slides prepared for this study and to consider whether or not this radiation protection education contributes to reducing the exposure of the operator's ocular lens. Thermoluminescent dosimeter (TLD) was installed at the outside left, inside left, outside right, and inside right of the X-ray protective eyewear of the operators performing the cardiac catheterization. The exposure dose rate before and after radiation protection education for 3 operators performing cardiac catheterization was compared. The exposure dose ratio was defined by dividing the TLD measurement value, which is the air kerma calculated by the X-ray diagnosis apparatus for the angiography. In other words, this can calculate the ratio of how much the operators are exposed to radiation from the dose of the patient per examination. When comparing the radiation dose ratio obtained from the dosimeter installed on the right outer side before and after education, p-value was <0.05 in the left anterior oblique-cranial and right anterior oblique- cranial, and a significant difference was recognized. The radiation protection education carried out in this study contributes to a reduction in the exposure dose of the operators.


Assuntos
Exposição Ocupacional , Exposição à Radiação , Proteção Radiológica , Cateterismo Cardíaco , Humanos , Doses de Radiação , Exposição à Radiação/prevenção & controle , Radiografia Intervencionista
5.
Artigo em Japonês | MEDLINE | ID: mdl-34305058

RESUMO

We conducted a nationwide multicenter survey of various interventional radiology (IVR) procedures. Data were collected from 385 X-ray systems in 126 institutions, including 432 cine programs and 380 digital subtraction angiography (DSA) programs for diagnostic catheterization, percutaneous coronary intervention (PCI), ablation, transcatheter aortic valve implantation (TAVI), neurologic IVR, thorax IVR, abdominal IVR, and endovascular therapy (EVT). Fluoroscopic and cine dose rates were 10.1 mGy/min and 110.7 mGy/min, respectively, whereas for DSA programs, the median fluoroscopic and DSA dose rates were 8.0 mGy/min and 224.8 mGy/min, respectively. The DSA dose rate was more than twice the cine dose rate. The largest difference between dose rates was for diagnostic catheterization, which had a cine dose rate of 142.6 mGy/min and a fluoroscopic dose rate of 12.6 mGy/min (by a factor of 12.5), followed by EVT, which had a DSA dose rate of 216.0 mGy/min and a fluoroscopic dose rate of 7.7 mGy/min (by a factor of 29.6). The smallest difference between dose rates was for TAVI, which had a cine dose rate of 96.8 mGy/min and a fluoroscopic dose rate of 12.0 mGy/min (by a factor of 8.9), followed by neurologic IVR, which had a DSA dose rate of 227.9 mGy/min and a fluoroscopic dose rate of 9.6 mGy/min (by a factor of 22.6). Compared with the fluoroscopic dose rates, the cine dose rates were 9-13 times higher and the DSA dose rates were 22-30 times higher; the DSA dose rates were more than double the cine dose rates.


Assuntos
Intervenção Coronária Percutânea , Radiografia Intervencionista , Angiografia Digital , Fluoroscopia , Doses de Radiação
7.
Phys Med ; 86: 75-81, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34062336

RESUMO

PURPOSE: To assess the task-based performance of images obtained under different focal spot size and acquisition mode on a dual-energy CT scanner. METHODS: Axial CT image series of the Catphan phantom were obtained using a tube focus at different sizes. Acquisitions were performed in standard single-energy, high resolution (HR) and dual-energy modes. Images were reconstructed using conventional and high definition (HD) kernels. Task-based transfer function at the 50% level (TTF50%) for teflon, delrin, low density polyethylene (LDPE) and acrylic, as well as image noise and noise texture, were assessed across all focal spots and acquisition modes using Noise Power Spectrum (NPS) analysis. A non-prewhitening mathematical observer model was used to calculate detectability index (dNPW'). RESULTS: TTF50% degraded with increasing focal spot size. TTF50% ranged from 0.67 mm-1 for teflon to 0.25 mm-1 for acrylic. For standard kernel, image noise and NPS-determined average spatial frequency were 8.3 HU and 0.29 mm-1, respectively in single-energy, 12.0 HU and 0.37 mm-1 in HR, and 7.9 HU and 0.26 mm-1 in dual-energy mode. For standard kernel, dNPW' was 61 in single-energy and HR mode and reduced to 56 in dual-energy mode. CONCLUSIONS: The task-based image quality assessment metrics have shown that spatial resolution is higher for higher image contrast materials and detectability is higher in the standard single-energy mode compared to HR and dual-energy mode. The results of the current study provide CT operators the required knowledge to characterize their CT system towards the optimization of its clinical performance.


Assuntos
Algoritmos , Tomografia Computadorizada por Raios X , Imagens de Fantasmas , Doses de Radiação , Razão Sinal-Ruído , Tomógrafos Computadorizados
8.
Phys Med ; 86: 91-97, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34062338

RESUMO

PURPOSE: To establish diagnostic reference levels (DRLs) and achievable levels (ALs) for the most common fluoroscopically guided interventions (FGIs) performed in operating rooms using mobile C-arm equipment. METHODS: A national survey was performed in 57 centers in France. Anonymous data from 6817 patients undergoing FGIs were prospectively collected over a period of 7 months. DRLs (third quartile of the distribution) and ALs (median of the distribution) were determined for each type of intervention in terms of kerma area product (KAP) and fluoroscopy time (FT). RESULTS: DRLs and ALs were proposed for 31 procedure types related to seven surgical specialties: orthopedics (n = 9), urology (n = 3), vascular (n = 6), cardiology (n = 5), neurosurgery (n = 3), gastrointestinal (n = 3), and multi-specialty (n = 2). DRLs in terms of KAP ranged from 0.1 Gy·cm2 for hallux valgus to 78 Gy·cm2 for abdominal aortic aneurysm endovascular repair. A factor of 155 was obtained between the FTs for a herniated lumbar disk (0.2 min) and an abdominal aortic aneurysm endovascular repair (31 min). The highest variations were obtained within orthopedic procedures in terms of KAP (ratio 122) and within gastrointestinal procedures in terms of FT (ratio 9). Overall, the FGIs associated with the highest radiation exposure (KAP > 10 Gy·cm2) were found in the cardiology, vascular, and gastrointestinal specialties. CONCLUSIONS: DRLs and ALs are suggested for a wide range of FGIs performed in operating rooms using a mobile C-arm. We aim at providing a practical optimization tool for medical physicists and surgeons.


Assuntos
Níveis de Referência de Diagnóstico , Salas Cirúrgicas , Fluoroscopia , França , Humanos , Doses de Radiação , Radiografia Intervencionista
10.
Artigo em Inglês | MEDLINE | ID: mdl-34068390

RESUMO

In radiography, the exposure index (EI), as per the International Electrotechnical Commission standard, depends on the incident beam quality and exposure dose to the digital radiography system. Today automatic exposure control (AEC) systems are commonly employed to obtain the optimal image quality. An AEC system can maintain a constant incident exposure dose on the image receptor regardless of the patient thickness. In this study, we investigated the relationship between body thickness, entrance surface dose (ESD), EI, and the exposure indicator (S value) with the aim of using EI as the dose optimization tool in digital chest radiography (posterior-anterior and lateral projection). The exposure condition from the Korean national survey for determining diagnostic reference levels and two digital radiography systems (photostimulable phosphor plate and indirect flat panel detector) were used. As a result, ESD increased as the phantom became thicker with constant exposure indicator, which indicates similar settings to an AEC system, but the EI indicated comparatively constant values without following the tendency of ESD. Therefore, body thickness should be considered under the AEC system for introducing EI as the dose optimization tool in digital chest radiography.


Assuntos
Intensificação de Imagem Radiográfica , Tórax , Humanos , Imagens de Fantasmas , Doses de Radiação , Radiografia
11.
Phys Med ; 85: 192-199, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34111631

RESUMO

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.


Assuntos
Imageamento Tridimensional , Cirurgia Assistida por Computador , Tomografia Computadorizada de Feixe Cônico , Humanos , Imagens de Fantasmas , Doses de Radiação , Tomografia Computadorizada por Raios X
12.
Eur J Radiol ; 141: 109808, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34120010

RESUMO

OBJECTIVES: To compare deep learning (True Fidelity, TF) and partial model based Iterative Reconstruction (ASiR-V) algorithm for image texture, low contrast lesion detectability and potential dose reduction. METHODS: Anthropomorphic phantoms (mimicking non-overweight and overweight patient), containing lesions of 6 mm in diameter with 20HU contrast, were scanned at five different dose levels (2,6,10,15,20 mGy) on a CT system, using clinical routine protocols for liver lesion detection. Images were reconstructed using ASiR-V 0% (surrogate for FBP), 60 % and TF at low, medium and high strength. Noise texture was characterized by computing a normalized Noise Power Spectrum filtered by an eye filter. The similarity against FBP texture was evaluated using peak frequency difference (PFD) and root mean square deviation (RMSD). Low contrast detectability was assessed using a channelized Hotelling observer and the area under the ROC curve (AUC) was used as figure of merit. Potential dose reduction was calculated to obtain the same AUC for TF and ASiR-V. RESULTS: FBP-like noise texture was more preserved with TF (PFD from -0.043mm-1 to -0.09mm-1, RMSD from 0.12mm-1 to 0.21mm-1) than with ASiR-V (PFD equal to 0.12 mm-1, RMSD equal to 0.53mm-1), resulting in a sharper image. AUC was always higher with TF than ASIR-V. In average, TF compared to ASiR-V, enabled a radiation dose reduction potential of 7%, 25 % and 33 % for low, medium and high strength respectively. CONCLUSION: Compared to ASIR-V, TF at high strength does not impact noise texture and maintains low contrast liver lesions detectability at significant lower dose.


Assuntos
Aprendizado Profundo , Neoplasias Hepáticas , Algoritmos , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Imagens de Fantasmas , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador , Tomografia Computadorizada por Raios X
13.
Eur J Radiol ; 141: 109825, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34144309

RESUMO

OBJECTIVE: To assess the diagnostic performance and reader confidence in determining the resectability of pancreatic cancer at computed tomography (CT) using a new deep learning image reconstruction (DLIR) algorithm. METHODS: A retrospective review was conduct of on forty-seven patients with pathologically confirmed pancreatic cancers who underwent baseline multiphasic contrast-enhanced CT scan. Image data sets were reconstructed using filtered back projection (FBP), hybrid model-based adaptive statistical iterative reconstruction (ASiR-V) 60 %, and DLIR "TrueFidelity" at low(L), medium(M), and high strength levels(H). Four board-certified abdominal radiologists reviewed the CT images and classified cancers as resectable, borderline resectable, or unresectable. Diagnostic performance and reader confidence for categorizing the resectability of pancreatic cancer were evaluated based on the reference standards, and the interreader agreement was assessed using Fleiss k statistics. RESULTS: For prediction of margin-negative resections(ie, R0), the average area under the receiver operating characteristic curve was significantly higher with DLIR-H (0.91; 95 % confidence interval [CI]: 0.79, 0.98) than FBP (0.75; 95 % CI:0.60, 0.86) and ASiR-V (0.81; 95 % CI:0.67, 0.91) (p = 0.030 and 0.023 respectively). Reader confidence scores were significantly better using DLIR compared to FBP and ASiR-V 60 % and increased linearly with the increase of DLIR strength level (all p < 0.001). Among the image reconstructions, DLIR-H showed the highest interreader agreement in the resectability classification and lowest subject variability in the reader confidence. CONCLUSIONS: The DLIR-H algorithm may improve the diagnostic performance and reader confidence in the CT assignment of the local resectability of pancreatic cancer while reducing the interreader variability.


Assuntos
Aprendizado Profundo , Neoplasias Pancreáticas , Algoritmos , Humanos , Processamento de Imagem Assistida por Computador , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/cirurgia , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador , Estudos Retrospectivos
14.
Br J Radiol ; 94(1123): 20201269, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34106750

RESUMO

OBJECTIVES: To compare diagnostic reference levels (DRLs) in paediatric fluoroscopy at a secondary referral centre with 2018 European guidelines. Secondly, to compare secondary referral centre DRLs for paediatric fluoroscopy examinations not included in European guidelines with 2010 national UK DRLs. METHODS: Paediatric fluoroscopy studies were grouped by age (groups: 0, 1, 5, 10, 15 years) for examination type and analysed retrospectively, over a period of 14 years. DRLs were compared with European DRLs (micturating cystourethrograms (MCUs)) and 2010 UK national DRLs (contrast swallows and meals). RESULTS: 1,586 studies were performed (49% MCUs; 31% meals; 9% swallows). For all age groups, DRLs for MCUs were lower than European DRLs by up to a factor 58 x (1 year age group: secondary referral centre DRL 12 mGycm2 vs European DRL 700 mGycm2). For contrast swallows and meals, 75th percentile doses were lower than 2010 UK national 25th percentile doses in all age groups. CONCLUSION: Maintaining low doses of ionising radiation is particularly important in paediatrics, and our study has found that it is possible to achieve low paediatric fluoroscopy doses in a secondary referral centre setting. ADVANCES IN KNOWLEDGE: Our data may prove useful to other centres and could contribute towards future European DRLs.


Assuntos
Níveis de Referência de Diagnóstico , Fluoroscopia/normas , Guias de Prática Clínica como Assunto , Encaminhamento e Consulta , Adolescente , Criança , Pré-Escolar , Europa (Continente) , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Doses de Radiação , Estudos Retrospectivos , Centros de Cuidados de Saúde Secundários
15.
Lancet Oncol ; 22(7): 1023-1033, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34126044

RESUMO

BACKGROUND: Conventional external beam radiotherapy is the standard palliative treatment for spinal metastases; however, complete response rates for pain are as low as 10-20%. Stereotactic body radiotherapy delivers high-dose, ablative radiotherapy. We aimed to compare complete response rates for pain after stereotactic body radiotherapy or conventional external beam radiotherapy in patients with painful spinal metastasis. METHODS: This open-label, multicentre, randomised, controlled, phase 2/3 trial was done at 13 hospitals in Canada and five hospitals in Australia. Patients were eligible if they were aged 18 years and older, and had painful (defined as ≥2 points with the Brief Pain Inventory) MRI-confirmed spinal metastasis, no more than three consecutive vertebral segments to be included in the treatment volume, an Eastern Cooperative Oncology Group performance status of 0-2, a Spinal Instability Neoplasia Score of less than 12, and no neurologically symptomatic spinal cord or cauda equina compression. Patients were randomly assigned (1:1) with a web-based, computer-generated allocation sequence to receive either stereotactic body radiotherapy at a dose of 24 Gy in two daily fractions or conventional external beam radiotherapy at a dose of 20 Gy in five daily fractions using standard techniques. Treatment assignment was done centrally by use of a minimisation method to achieve balance for the stratification factors of radiosensitivity, the presence or absence of mass-type tumour (extraosseous or epidural disease extension, or both) on imaging, and centre. The primary endpoint was the proportion of patients with a complete response for pain at 3 months after radiotherapy. The primary endpoint was analysed in the intention-to-treat population and all safety and quality assurance analyses were done in the as-treated population (ie, all patients who received at least one fraction of radiotherapy). The trial is registered with ClinicalTrials.gov, NCT02512965. FINDINGS: Between Jan 4, 2016, and Sept 27, 2019, 229 patients were enrolled and randomly assigned to receive conventional external beam radiotherapy (n=115) or stereotactic body radiotherapy (n=114). All 229 patients were included in the intention-to-treat analysis. The median follow-up was 6·7 months (IQR 6·3-6·9). At 3 months, 40 (35%) of 114 patients in the stereotactic body radiotherapy group, and 16 (14%) of 115 patients in the conventional external beam radiotherapy group had a complete response for pain (risk ratio 1·33, 95% CI 1·14-1·55; p=0·0002). This significant difference was maintained in multivariable-adjusted analyses (odds ratio 3·47, 95% CI 1·77-6·80; p=0·0003). The most common grade 3-4 adverse event was grade 3 pain (five [4%] of 115 patients in the conventional external beam radiotherapy group vs five (5%) of 110 patients in the stereotactic body radiotherapy group). No treatment-related deaths were observed. INTERPRETATION: Stereotactic body radiotherapy at a dose of 24 Gy in two daily fractions was superior to conventional external beam radiotherapy at a dose of 20 Gy in five daily fractions in improving the complete response rate for pain. These results suggest that use of conformal, image-guided, stereotactically dose-escalated radiotherapy is appropriate in the palliative setting for symptom control for selected patients with painful spinal metastases, and an increased awareness of the need for specialised and multidisciplinary involvement in the delivery of end-of-life care is needed. FUNDING: Canadian Cancer Society and the Australian National Health and Medical Research Council.


Assuntos
Dor nas Costas/etiologia , Radiocirurgia , Neoplasias da Coluna Vertebral/radioterapia , Adolescente , Adulto , Idoso , Austrália , Dor nas Costas/diagnóstico , Canadá , Fracionamento da Dose de Radiação , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Medição da Dor , Doses de Radiação , Radiocirurgia/efeitos adversos , Neoplasias da Coluna Vertebral/complicações , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Neoplasias da Coluna Vertebral/secundário , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
16.
Oper Neurosurg (Hagerstown) ; 21(Suppl 1): S39-S45, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34128066

RESUMO

BACKGROUND: Spine surgery has seen tremendous growth in the past 2 decades. A variety of safety, practical, and market-driven needs have spurred the development of new imaging technologies as necessary tools for modern-day spine surgery. Although current imaging techniques have proven satisfactory for operative needs, it is well-known that these techniques have negative consequences for operators and patients in terms of radiation risk. Several mitigating techniques have arisen in recent years, ranging from lead protection to radiation-reducing protocols, although each technique has limits. A hitherto-problematic barrier has been the fact that efforts to diminish radiation emission come at the cost of reduced image quality. OBJECTIVE: To describe new ultra-low radiation imaging modalities that have the potential to drastically reduce radiation risk and minimize unacceptable adverse effects. METHODS: A literature review was performed of articles and studies that used either of 2 ultra-low radiation imaging modalities, the EOS system (EOS-Imaging S.A., Paris, France) and LessRay (NuVasive, San Diego, CA). RESULTS: Both ultra-low radiation imaging modalities reduce radiation exposure in the preoperative and perioperative settings. EOS provides 3-dimensional reconstructive capability, and LessRay offers intraoperative tools that facilitate spinal localization and proper visual alignment of the spine. CONCLUSION: These novel radiation-reducing technologies diminish patient and surgeon exposure, aid the surgeon in preoperative planning, and streamline intraoperative workflow.


Assuntos
Exposição à Radiação , Coluna Vertebral , Fluoroscopia , Humanos , Processamento de Imagem Assistida por Computador , Doses de Radiação , Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/cirurgia
17.
Br J Radiol ; 94(1123): 20210252, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34142869

RESUMO

Shielding, particularly of the gonads, has been a routine part of diagnostic radiographic imaging for many years. However, recent thinking suggests that such shielding may offer little benefit, and in some cases may actually cause harm, e.g. by obscuring anatomy or paradoxically increasing patient radiation dose secondary to the need for repeat imaging. This thinking has led many institutions in the West to abandon routine shielding. However, in Asia, shielding is still commonplace. It was felt that the Asia-Pacific Forum on Quality and Safety in Medical Imaging (APQS) was an ideal place to discuss the merits of shielding and deliver a pan-Asian consensus. The APQS is an annual meeting that convenes radiation safety and imaging quality experts from all of the major Asian regions. During the 2020 APQS meeting, radiation safety experts from each region discussed their opinions of shielding during a dedicated session. These experts' views were mostly in line with the views of Western radiologists. However, important country specific and cultural factors were noted by each of the experts. A pan-Asian consensus was issued by the forum. It is hoped that this consensus will guide the development of future shielding policies throughout Asia.


Assuntos
Diagnóstico por Imagem , Proteção Radiológica/métodos , Ásia , Congressos como Assunto , Consenso , Características Culturais , Humanos , Doses de Radiação
18.
J Pediatr Orthop ; 41(6): 389-394, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34096557

RESUMO

BACKGROUND: Intraoperative fluoroscopy facilitates minimally invasive surgery, and although it is irreplaceable in terms of intraoperative guidance, it results in substantial radiation exposure to the patient and surgical team. Although the risk of radiation exposure because of equipment factors has been described, there is little known about the impact of surgeon experience on radiation exposure. The aim of this study was to determine whether there is a relationship between years of surgical experience and total dose of radiation used for an archetypal pediatric orthopaedic surgical procedure that requires intraoperative fluoroscopy. METHODS: This was a retrospective cohort study of children undergoing closed reduction and percutaneous pinning for supracondylar humerus fractures at a level I pediatric trauma center. Information pertaining to radiation dosage was gathered including fluoroscopic time, total images acquired, magnification use, and dose area product (DAP). Regression analysis was used to evaluate the effect of surgeon experience on the outcome variables. RESULTS: A total of 759 pediatric patients treated by 17 attending surgeons were included. The median surgeon experience was 8.94 years (interquartile range, 5.9 to 19.8). Increased number of pins was associated with increased DAP (P<0.001) and lower years of experience (P=0.025). There was significantly higher fluoroscopy time in seconds (56.9 vs. 42.1 s, P=0.001), DAP (179.9 vs. 110.3 mGy-cm2, P=0.001), use of magnification (39.5 vs. 31.9 s, P=0.043), and total number of images obtained (74.5 vs. 57.6, P=0.008) in attending surgeons with <1 year of experience compared with those with greater experience. An operator extremity was visible in at least 1 saved image in 263 of 759 (35%) cases. CONCLUSION: Increased surgical experience was significantly associated with decreased fluoroscopy usage, including time, number of images, and dose. Surgeon inexperience increases radiation exposure for patients and staff by over 60% when treating supracondylar humerus fractures. This study clearly identifies methods to reduce radiation exposure, including use of pulsed fluoroscopy instead of continuous fluoroscopy, decreasing use of magnification, removing the operator's extremity from the field, and judicious use and placement of each additional pin. LEVEL OF EVIDENCE: Level III.


Assuntos
Competência Clínica , Fraturas do Úmero/cirurgia , Exposição Ocupacional , Exposição à Radiação , Pinos Ortopédicos , Criança , Pré-Escolar , Redução Fechada , Feminino , Fluoroscopia , Humanos , Masculino , Salas Cirúrgicas , Doses de Radiação , Estudos Retrospectivos , Cirurgiões , Fatores de Tempo
19.
J Appl Clin Med Phys ; 22(7): 286-296, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34159736

RESUMO

PURPOSE: In an ultrahigh-resolution CT (U-HRCT), deep learning-based reconstruction (DLR) is expected to drastically reduce image noise without degrading spatial resolution. We assessed a new algorithm's effect on image quality at different radiation doses assuming an abdominal CT protocol. METHODS: For the normal-sized abdominal models, a Catphan 600 was scanned by U-HRCT with 100%, 50%, and 25% radiation doses. In all acquisitions, DLR was compared to model-based iterative reconstruction (MBIR), filtered back projection (FBP), and hybrid iterative reconstruction (HIR). For the quantitative assessment, we compared image noise, which was defined as the standard deviation of the CT number, and spatial resolution among all reconstruction algorithms. RESULTS: Deep learning-based reconstruction yielded lower image noise than FBP and HIR at each radiation dose. DLR yielded higher image noise than MBIR at the 100% and 50% radiation doses (100%, 50%, DLR: 15.4, 16.9 vs MBIR: 10.2, 15.6 Hounsfield units: HU). However, at the 25% radiation dose, the image noise in DLR was lower than that in MBIR (16.7 vs. 26.6 HU). The spatial frequency at 10% of the modulation transfer function (MTF) in DLR was 1.0 cycles/mm, slightly lower than that in MBIR (1.05 cycles/mm) at the 100% radiation dose. Even when the radiation dose decreased, the spatial frequency at 10% of the MTF of DLR did not change significantly (50% and 25% doses, 0.98 and 0.99 cycles/mm, respectively). CONCLUSION: Deep learning-based reconstruction performs more consistently at decreasing dose in abdominal ultrahigh-resolution CT compared to all other commercially available reconstruction algorithms evaluated.


Assuntos
Aprendizado Profundo , Algoritmos , Humanos , Melhoria de Qualidade , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador , Tomografia Computadorizada por Raios X
20.
Artigo em Chinês | MEDLINE | ID: mdl-34074088

RESUMO

Objective: To analyze the individual dose level of occupational external radiation of radiation workers in Lanzhou in 2019, so as to provide reference for radiation protection and occupational health management. Methods: In April 2020, a total of 1460 radiation workers in Gansu Provincial Center for Disease Control and Prevention in 2019 were selected as the research objects. The unit nature, hospital level and occupational category of the monitored workers were collected, and the monitoring results of external radiation personal dose in 2019 were analyzed and compared. Results: In the occupational external radiation monitoring of radiation workers in Lanzhou in 2019, the effective dose of 48 persons was 1.0~<5.0 mSv, the effective dose of 2 persons was 5.0~<10.0 mSv, the annual collective effective dose was 308.21 people·mSv, and the average annual effective dose of monitored persons was 0.21 mSv/a. There was significant difference in the distribution of annual effective dose per capita among different occupational groups (H=34.43, P<0.05) . The annual effective dose per capita of nuclear medicine personnel was higher (0.56 mSv/a) , followed by interventional radiology (0.33 mSv/a) . The ratio of annual collective dose to total annual collective dose with annual individual dose more than 5 mSv (SR(5)) and the ratio of the number of staff with annual individual dose more than 1mSv to the total number of monitored personnel (NR(1)) were higher in nuclear medicine and interventional radiology personnel. The average annual effective dose distribution of diagnostic radiologists in different level hospitals was statistically significant (H=16.46, P<0.05) . The average annual effective dose in private hospitals, community hospitals and health centers was higher (0.32 mSv) , followed by county hospitals (0.23 mSv) . Conclusion: The individual dose of occupational external radiation of radiation workers in Lanzhou is generally low, and the annual effective dose of nuclear medicine and interventional radiology workers is high. The management of radiation protection should be emphasis on this people. And it is suggested to strengthen the supervision of private hospitals and update and maintain the equipment of community health centers.


Assuntos
Exposição Ocupacional , Saúde do Trabalhador , Monitoramento de Radiação , Proteção Radiológica , Humanos , Exposição Ocupacional/análise , Doses de Radiação
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