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PURPOSE: To investigate whether pre-procedure Computed Tomography Angiography (CTA) improves radiation exposure, procedure complexity, and symptom recurrence after bronchial embolization for massive hemoptysis. MATERIAL AND METHODS: A single-center retrospective review of bronchial artery embolization (BAE) for massive hemoptysis was performed for procedures between 2008 and 2019. Multi-variate analysis was performed to determine the significance of pre-procedure CTA and etiology of hemoptysis on patient radiation exposure (reference point air kerma, RPAK) and rate of recurrent hemoptysis. RESULTS: There were 61 patients (mean age 52.5 years; SD = 19.2 years, and 57.3% male) and CTA was obtained for 42.6% (26/61). Number of vessels selected was a mean of 7.2 (SD = 3.4) in those without CTA and 7.4 (SD = 3.4) in those with CTA (p = 0.923). Mean procedure duration was 1.8 h (SD = 1.6 h) in those without CTA and 1.3 h (SD = 1.0 h) in those with CTA (p = 0.466). Mean fluoroscopy time and RPAK per procedure were 34.9 min (SD = 21.5 min) and 1091.7 mGy (SD = 1316.6 mGy) for those without a CTA and 30.7 min (SD = 30.7 min) and 771.5 mGy (SD = 590.0 mGy) for those with a CTA (p = 0.523, and p = 0.879, respectively). Mean total iodine given was 49.2 g (SD = 31.9 g) for those without a CTA and 70.6 g (SD = 24.9 g) for those with a CTA (p = 0.001). Ongoing hemoptysis at last clinical follow up was 13/35 (37.1%) in those without CTA and 9/26 (34.6%) in those with CTA (p = 0.794). CONCLUSIONS: Pre-procedure CTA did not improve radiation effective dose and symptom recurrence after BAE and is associated with significant increases in total iodine dose.
Assuntos
Embolização Terapêutica , Hemoptise , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , Hemoptise/diagnóstico , Angiografia por Tomografia Computadorizada , Tomografia Computadorizada por Raios X/efeitos adversos , Angiografia/efeitos adversos , Artérias Brônquicas/diagnóstico por imagem , Embolização Terapêutica/métodos , Estudos Retrospectivos , Doses de Radiação , Resultado do TratamentoRESUMO
OB JECTIVES: The European Society of Radiology identified 10 common indications for computed tomography (CT) as part of the European Study on Clinical Diagnostic Reference Levels (DRLs, EUCLID), to help standardize radiation doses. The objective of this study is to generate DRLs and median doses for these indications using data from the UCSF CT International Dose Registry. METHODS: Standardized data on 3.7 million CTs in adults were collected between 2016 and 2019 from 161 institutions across seven countries (United States of America (US), Switzerland, Netherlands, Germany, UK, Israel, Japan). DRLs (75th percentile) and median doses for volumetric CT-dose index (CTDIvol) and dose-length product (DLP) were assessed for each EUCLID category (chronic sinusitis, stroke, cervical spine trauma, coronary calcium scoring, lung cancer, pulmonary embolism, coronary CT angiography, hepatocellular carcinoma (HCC), colic/abdominal pain, appendicitis), and US radiation doses were compared with European. RESULTS: The number of CT scans within EUCLID categories ranged from 8,933 (HCC) to over 1.2 million (stroke). There was greater variation in dose between categories than within categories (p < .001), and doses were significantly different between categories within anatomic areas. DRLs and median doses were assessed for all categories. DRLs were higher in the US for 9 of the 10 indications (except chronic sinusitis) than in Europe but with a significantly higher sample size in the US. CONCLUSIONS: DRLs for CTDIvol and DLP for EUCLID clinical indications from diverse organizations were established and can contribute to dose optimization. These values were usually significantly higher in the US than in Europe. KEY POINTS: ⢠Registry data were used to create benchmarks for 10 common indications for CT identified by the European Society of Radiology. ⢠Observed US radiation doses were higher than European for 9 of 10 indications (except chronic sinusitis). ⢠The presented diagnostic reference levels and median doses highlight potentially unnecessary variation in radiation dose.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Adulto , Níveis de Referência de Diagnóstico , Humanos , Doses de Radiação , Valores de Referência , Sistema de Registros , Tomografia Computadorizada por Raios XRESUMO
The half-value layer (HVL) is one of the regulatory required radiation safety parameters that needs to be measured annually. With the advent of solid state detectors and their associated electrometer assembly, the HVL measurement can be conducted with relative ease. In fact, various radiological technique parameters such as tube potential (kV), exposure time in millisecond (msec), air kerma (mGy), and air kerma rate (mGy/sec) can be obtained along with the HVL with just one exposure. The measured (or, calculated) HVL is based on radiation detection systems calibrated for conventional x-ray systems equipped with tungsten anode and added aluminum filters (molybdenum anode and filter in the case of mammography systems). However, a new generation of radiography and fluoroscopy (R/F) systems, inclusive of interventional angiography equipment, is equipped with varying thicknesses and materials of spectral shaping filters (SSF) to minimize the radiation exposure to the patients while image quality is maintained and optimized. The accuracy of HVL obtained with new generation of R/F systems has not been investigated in depth due to the addition of spectral filters yielding a harder beam quality with a higher HVL than the regulatory required value of 2.9 mm Al HVL at 80 kV. It would be of great interest to determine the accuracy of HVL as measured (or, calculated) by the solid state detector systems (SSDS), especially when accurate radiation dose delivered to the patient is required. In this investigation, the subject is limited to the accuracy of HVL measurement for conventional R/F systems.
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Mamografia , Tungstênio , Fluoroscopia , Humanos , Doses de Radiação , Radiografia , Raios XRESUMO
Importance: Computed tomography (CT) radiation doses vary across institutions and are often higher than needed. Objective: To assess the effectiveness of 2 interventions to reduce radiation doses in patients undergoing CT. Design, Setting, and Participants: This randomized clinical trial included 864â¯080 adults older than 18 years who underwent CT of the abdomen, chest, combined abdomen and chest, or head at 100 facilities in 6 countries from November 1, 2015, to September 21, 2017. Data analysis was performed from October 4, 2017, to December 14, 2018. Interventions: Imaging facilities received audit feedback alone comparing radiation-dose metrics with those of other facilities followed by the multicomponent intervention, including audit feedback with targeted suggestions, a 7-week quality improvement collaborative, and best-practice sharing. Facilities were randomly allocated to the time crossing from usual care to the intervention. Main Outcomes and Measures: Primary outcomes were the proportion of high-dose CT scans and mean effective dose at the facility level. Secondary outcomes were organ doses. Outcomes after interventions were compared with those before interventions using hierarchical generalized linear models adjusting for temporal trends and patient characteristics. Results: Across 100 facilities, 864â¯080 adults underwent 1â¯156â¯657 CT scans. The multicomponent intervention significantly reduced proportions of high-dose CT scans, measured using effective dose. Absolute changes in proportions of high-dose scans were 1.1% to 7.9%, with percentage reductions in the proportion of high-dose scans of 4% to 30% (abdomen: odds ratio [OR], 0.82; 95% CI, 0.77-0.88; P < .001; chest: OR, 0.92; 95% CI, 0.86-0.99; P = .03; combined abdomen and chest: OR, 0.49; 95% CI, 0.41-0.59; P < .001; and head: OR, 0.71; 95% CI, 0.66-0.76; P < .001). Reductions in the proportions of high-dose scans were greater when measured using organ doses. The absolute reduction in the proportion of high-dose scans was 6.0% to 17.2%, reflecting 23% to 58% reductions in the proportions of high-dose scans across anatomical areas. Mean effective doses were significantly reduced after multicomponent intervention for abdomen (6% reduction, P < .001), chest (4%, P < .001), and chest and abdomen (14%, P < .001) CT scans. Larger reductions in mean organ doses were 8% to 43% across anatomical areas. Audit feedback alone reduced the proportions of high-dose scans and mean dose, but reductions in observed dose were smaller. Radiologist's satisfaction with CT image quality was unchanged and high during all periods. Conclusions and Relevance: For imaging facilities, detailed feedback on CT radiation dose combined with actionable suggestions and quality improvement education significantly reduced doses, particularly organ doses. Effects of audit feedback alone were modest. Trial Registration: ClinicalTrials.gov Identifier: NCT03000751.
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Abdome/diagnóstico por imagem , Doses de Radiação , Tórax/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Cabeça , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Modern fluoroscopes pose a challenge for the clinical physicist for annual testing and continued upkeep. These fluoroscopes are critical to providing care to patients for complex interventions, and continue to evolve in automated image quality adjustments. Few tools in software or hardware currently exist to assist the physicist or technologist in gauging fluoroscope constancy or readiness for procedures. Many modalities such as mammography, computed tomography or even magnetic resonance imaging are much more evolved with respect to testing or quality control. In this work we sought to provide simple reproducible tools and methods for spot evaluating or continued quality testing of interventional fluoroscopes.
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Fluoroscopia/métodos , Fluoroscopia/normas , Imagens de Fantasmas , Controle de Qualidade , Radiografia Intervencionista/métodos , Razão Sinal-Ruído , Humanos , Processamento de Imagem Assistida por Computador/métodos , Doses de Radiação , Estudos Retrospectivos , SoftwareRESUMO
BACKGROUND: Technetium 99m N-DBODC5 is a new myocardial perfusion tracer shown to exhibit high heart uptake and rapid liver clearance in normal rats. The objectives of this canine study were (1) to compare the organ biodistribution and myocardial uptake, washout, and redistribution kinetics of Tc-99m N-DBODC5 with Tc-99m sestamibi over a period of 3 hours in a more clinically relevant large animal species and (2) to compare the myocardial uptake of Tc-99m N-DBODC5 with thallium 201 when co-injected during vasodilator stress in dogs with coronary stenoses. METHODS AND RESULTS: At peak adenosine-induced hyperemia, 10 dogs with critical left anterior descending artery stenoses received either Tc-99m N-DBODC5 (n = 6) or Tc-99m sestamibi (n = 4) and microspheres, followed by serial imaging and blood sampling over a period of 3 hours. Another 14 dogs with either critical (n = 7) or mild (n = 7) left anterior descending artery stenoses underwent simultaneous injection of Tc-99m N-DBODC5, Tl-201, and microspheres during peak vasodilator stress. Like sestamibi, Tc-99m N-DBODC5 showed good myocardial uptake with slow washout and minimal redistribution over a period of 3 hours (P = not significant); however, Tc-99m N-DBODC5 cleared more rapidly from the liver (heart-lung ratio at 30 minutes, 0.92+/-0.11 versus 0.51 +/- 0.05; P < .05). When injected during hyperemic flow, the myocardial extraction plateau for Tc-99m N-DBODC5 was lower than that for Tl-201 and was intermediate between Tc-99m sestamibi and Tc-99m tetrofosmin. CONCLUSIONS: Excellent organ biodistribution and myocardial uptake and clearance kinetic properties, combined with rapid liver clearance and a favorable flow-extraction relationship, make Tc-99m N-DBODC5 a very promising new myocardial perfusion imaging agent.