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1.
Quintessence Int ; 51(3): 238-245, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32020134

RESUMEN

OBJECTIVES: Replacing conventional round intraoral collimators with rectangular collimators provides a considerable radiation dose reduction in adult patients. This study aimed to determine the radiation dose reduction via mathematical phantom when converting from round to appropriately sized rectangular collimation in children ages 5 to 15 years. METHOD AND MATERIALS: Virtual full mouth series (FMX) were simulated using a commercially available radiation dose software. This software is designed to calculate patient radiation doses from x-ray exams for various age pediatric and adult mathematical phantoms. For this pediatric study an 18-image FMX was simulated for the 15-year-old and a 12-image FMX was simulated for the 5-year-old and 10-year-old pediatric phantoms. An area of 12.0 to 16.8 cm2 represented rectangular collimation, while a 20.4 to 31.7 cm2 area represented typical round collimation. RESULTS: Effective doses decreased in all ages by nearly 60% when switching from 31.7 cm2 round to 12.0 cm2 rectangular collimation. Reduction in absorbed doses to the thyroid (70% to 73%), salivary glands (62% to 78%), and active bone marrow (60% to 62%) were also noted when switching from the largest to smallest collimation. CONCLUSION: This study suggests the use of rectangular collimators provides clinically relevant dose reduction for pediatric patients, even when altering from smaller round to rectangular collimation with equivalent beam quality, and this information can be utilized in all dental practices.


Asunto(s)
Programas Informáticos , Glándula Tiroides , Adolescente , Adulto , Niño , Preescolar , Humanos , Fantasmas de Imagen , Dosis de Radiación
2.
Pediatr Dent ; 42(1): 41-46, 2020 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-32075710

RESUMEN

Purpose: This study's purpose was to evaluate the effective dose (E) and equivalent dose (HT) of exposing a pediatric phantom to the extraoral bitewing programs of the Planmeca ProMax 2D S3 (ProMax) and Instrumentarium Orthopantomograph OP30 (OP30) and compare these results with dosimetry associated with the intraoral bitewing and panoramic radiograph. Methods: Dosimetry was acquired by placing 24 dosimeters in tissues of interest in a 10-year-old phantom. Manufacturer child settings were used for all scans. Repeat exposures of 20 scans were utilized. The average values of E and HT were calculated. Results: The E for the ProMax and OP30 units, respectively, were 16.84 µSv and 5.82 µSv. The highest E for both units was delivered to the thyroid, remainder tissues, and salivary glands. The highest HT for both units was delivered to the oral mucosa, salivary glands, extrathoracic airway, and thyroid. The mean differences between units were statistically significant (P<0.05). Conclusions: The average effective dose of the ProMax was higher than for the OP30. The effective dose of the pediatric extraoral bitewing is three to 11 times higher than that of the intraoral bitewing and comparable to the traditional panoramic radiograph of a pediatric phantom. Pediatric extraoral bitewing radiation protection guidelines are recommended.


Asunto(s)
Protección Radiológica , Niño , Humanos , Fantasmas de Imagen , Dosis de Radiación , Radiografía Panorámica , Glándulas Salivales , Glándula Tiroides
3.
J Comput Assist Tomogr ; 44(1): 7-12, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31939875

RESUMEN

OBJECTIVE: The aim of the study was to investigate the feasibility of coronary computed tomography (CT) angiography with a low kilovoltage peak scan and a refined scan timing prediction using a small contrast medium (CM) dose. METHODS: In protocol A, 120-kVp scanning and a standard CM dose were used. The scan timing was fixed. In protocol B, 80 kVp and a 60% CM dose were used. The scan timing was determined according to the interval from the CM arrival to the peak time in the ascending aorta. We measured the CT number and recorded the radiation dose. RESULTS: Higher CT numbers were observed in the left circumflex (proximal, P = 0.0235; middle, P = 0.0007; distal, P < 0.0001) in protocol B compared with protocol A. The radiation dose in protocol B was significantly lower than in protocol A (2.2 ± 0.9 vs 4.3 ± 1.7 mSv). CONCLUSIONS: Low-contrast, low-radiation dose, high-image quality coronary CT angiography can be performed with low kilovoltage peak scanning and a refined scan timing prediction.


Asunto(s)
Angiografía por Tomografía Computarizada/métodos , Medios de Contraste/administración & dosificación , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Intensificación de Imagen Radiográfica/métodos , Anciano , Cálculo de Dosificación de Drogas , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dosis de Radiación , Estudios Retrospectivos
4.
J Comput Assist Tomogr ; 44(1): 13-19, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31939876

RESUMEN

OBJECTIVE: To evaluate image quality and radiation dose exposure of low-kV setting and low-volume contrast medium (CM) computed tomography angiography (CTA) protocol for transcatheter aortic valve implantation (TAVI) planning in comparison with standard CTA protocol. METHODS: Sixty-patients were examined with 256-row MDCT for TAVI planning: 32 patients (study group) were evaluated using 80-kV electrocardiogram-gated protocol with 60 mL of CM and IMR reconstruction; 28 patients underwent a standard electrocardiogram-gated CTA study (100 kV; 80 mL of CM; iDose4 reconstruction). Subjective and objective image quality was evaluated in each patient at different aortic levels. Finally, we collected radiation dose exposure data (CT dose index and dose-length product) of both groups. RESULTS: In study protocol, significant higher mean attenuation values were achieved in all measurements compared with the standard protocol. There were no significant differences in the subjective image quality evaluation in both groups. Mean dose-length product of study group was 56% lower than in the control one (P < 0.0001). CONCLUSION: Low-kV and low-CM volume CTA, combined with IMR, allows to correctly performing TAVI planning with high-quality images and significant radiation dose reduction compared with standard CTA protocol.


Asunto(s)
Estenosis de la Válvula Aórtica/diagnóstico por imagen , Angiografía por Tomografía Computarizada/métodos , Medios de Contraste/administración & dosificación , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Adulto , Anciano , Anciano de 80 o más Años , Algoritmos , Estenosis de la Válvula Aórtica/cirugía , Femenino , Humanos , Bases del Conocimiento , Masculino , Persona de Mediana Edad , Tomografía Computarizada Multidetector , Periodo Preoperatorio , Dosis de Radiación , Reemplazo de la Válvula Aórtica Transcatéter
5.
J Comput Assist Tomogr ; 44(1): 20-25, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31939877

RESUMEN

OBJECTIVES: The purpose of this study was to evaluate whether quantitative analysis of lower leg muscle enhancement measured from dynamic computed tomographic angiography (dyn-CTA) could be used for diagnosis of peripheral arterial occlusive disease. METHODS: Patients (N = 35) with known peripheral arterial occlusive disease underwent the dyn-CTA of calves first. Five minutes later, standard CTA of the peripheral runoff from the diaphragm to the toes was performed. A runoff score was assigned by radiologists as a reference standard for each of 4 lower leg artery segments. The lower leg muscle enhancement measured from the dyn-CTA was analyzed by using quantitative kinetic parameters, including initial enhancement (E1), peak enhancement (Epeak), and enhancement ratio (ER) calculated from average time attenuation curves. In addition, histogram of lower leg muscle enhancement was evaluated by using the first enhanced phase images. RESULTS: Lower extremities were diagnosed as a normal group (n = 22) with each vessel segment score equals to 1 or lower and runoff score, 7 or lower, and otherwise as an ischemia group (n = 48). Average ± SD E1 is 91.4% ± 8.5% and 82.3% ± 10.7%, Epeak is 122.7% ± 10.4% and 115.6% ± 11.1%, and ER is 0.75 ± 0.05 and 0.72 ± 0.09 for normal and ischemia group, respectively. Statistical analysis showed that average E1 and Epeak for the ischemia group were significantly lower (P < 0.05) than the normal group. The histogram analysis demonstrated that mean and median of muscle enhancement in the ischemia group were significantly smaller (P < 0.05), and coefficient of variation (CV) was significantly larger (P < 0.05) than the normal group. There were weak negative correlations (r = -0.42, P < 0.05) between runoff scores and E1 and Epeak, and weak positive correlation (r = 0.40, P < 0.05) between runoff scores and CV. The receiver operating characteristics analysis between the 2 groups had area under the curve of 0.77 and 0.76 for E1 and CV, respectively. CONCLUSIONS: Lower leg muscle enhancement measured from the dyn-CTA could be assessed quantitatively to assist diagnosis of ischemia in clinical practice.


Asunto(s)
Arteriopatías Oclusivas/diagnóstico por imagen , Angiografía por Tomografía Computarizada/métodos , Extremidad Inferior/diagnóstico por imagen , Músculo Esquelético/diagnóstico por imagen , Enfermedad Arterial Periférica/diagnóstico por imagen , Adulto , Anciano , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dosis de Radiación
6.
J Comput Assist Tomogr ; 44(1): 32-36, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31939879

RESUMEN

OBJECTIVE: To evaluate the effect of ultra high-resolution computed tomography (UHRCT) and model-based iterative reconstruction (MBIR) on the detectability of simulated submillimeter artery. METHODS: A small vessel phantom ranging from 0.4 to 2.0 mm in diameter and edge phantoms of low to high attenuation values were scanned by UHRCT (super-high-resolution mode and normal-resolution-mode) and conventional CT, and data were reconstructed by MBIR and filtered back projection (FBP). Vessel detectability was assessed subjectively and the effective size at which 50% of response was achieved (ES50 [mm]) was calculated. Modulation transfer function (MTF) was calculated by an edge spread function method. RESULTS: ES50 of super high-resolution mode (0.36 mm for MBIR and 0.50 mm for FBP) was significantly smaller than those of normal-resolution mode (P < 0.01). In the MTF analysis, the MTF of MBIR improved as the edge phantom attenuation increased, whereas that of FBP was stable. CONCLUSIONS: Both UHRCT and MBIR are effective for the detectability of simulated submillimeter artery.


Asunto(s)
Angiografía por Tomografía Computarizada/métodos , Vasos Coronarios/diagnóstico por imagen , Algoritmos , Humanos , Fantasmas de Imagen , Dosis de Radiación , Interpretación de Imagen Radiográfica Asistida por Computador
7.
J Comput Assist Tomogr ; 44(1): 95-101, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31939889

RESUMEN

PURPOSE: This study aimed to evaluate image quality of ultra-low dose chest computed tomography using 6 iterative reconstruction (IR) algorithms. METHOD: A lung phantom was scanned on 4 computed tomography scanners using fixed tube voltages and the lowest mAs available on each scanner, resulting in dose levels of 0.1 to 0.2 mGy (80 kVp) and 0.3 to 1 mGy (140 kVp) volume CT dose index (CTDIvol). Images were reconstructed with IR available on the scanners. Image noise, signal-to-noise ratios, contrast-to-noise ratios, uniformity, and noise power spectrum (NPS) were assessed for evaluation of image quality. RESULTS: Image quality parameters increased with increasing dose for all algorithms. At constant dose levels, model-based techniques improved the contrast-to-noise ratio of lesions more than the statistical algorithms. All algorithms tested at 0.1 mGy showed lower NPS peak frequencies compared with 0.39 mGy. In contrast to the statistical techniques, model-based algorithms showed lower NPS peak frequencies at the lowest doses, indicating a coarser and blotchier noise texture. CONCLUSION: This study shows the importance of evaluating IR when introduced clinically.


Asunto(s)
Pulmón/diagnóstico por imagen , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Tomografía Computarizada por Rayos X/instrumentación , Algoritmos , Medios de Contraste , Humanos , Fantasmas de Imagen , Dosis de Radiación , Relación Señal-Ruido
8.
J Comput Assist Tomogr ; 44(1): 153-159, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31939897

RESUMEN

OBJECTIVE: The aim of this study was to assess the utility of 70-kilovoltage-peak (kVp) contrast-enhanced computed tomography (CECT) for visualization and identification of the right adrenal vein (RAV) in comparison with that of conventional 120-kVp CECT. METHODS: This retrospective study included patients who underwent adrenal venous sampling with concurrent biphasic 120-kVp (120-kVp group, n = 43) or 70-kVp (70-kVp group, n = 47) CECT. Signal-to-noise ratios, contrast-to-noise ratios, longitudinal lengths, conspicuity scores, RAV detection rates, and size-specific dose estimates were compared between the 2 groups. RESULTS: In comparison with the 120-kVp group, the 70-kVp group had significantly higher signal-to-noise and contrast-to-noise ratios (P < 0.001-P = 0.033), greater longitudinal lengths (P < 0.001-P = 0.002), superior conspicuity scores for the RAV (P < 0.001), higher RAV detection rates (P = 0.015-P = 0.033), and lower size-specific dose estimates (P < 0.001). CONCLUSIONS: Seventy-kilovoltage-peak CECT has advantages over conventional 120-kVp CECT and is potentially useful for noninvasive assessment of the precise anatomy of the RAV.


Asunto(s)
Glándulas Suprarrenales/irrigación sanguínea , Angiografía por Tomografía Computarizada/métodos , Hiperaldosteronismo/diagnóstico por imagen , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dosis de Radiación , Estudios Retrospectivos , Sensibilidad y Especificidad , Relación Señal-Ruido
9.
Bone Joint J ; 102-B(1): 5-10, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31888369

RESUMEN

AIMS: Intraoperative 3D navigation (ION) allows high accuracy to be achieved in spinal surgery, but poor workflow has prevented its widespread uptake. The technical demands on ION when used in patients with adolescent idiopathic scoliosis (AIS) are higher than for other more established indications. Lean principles have been applied to industry and to health care with good effects. While ensuring optimal accuracy of instrumentation and safety, the implementation of ION and its associated productivity was evaluated in this study for AIS surgery in order to enhance the workflow of this technique. The aim was to optimize the use of ION by the application of lean principles in AIS surgery. METHODS: A total of 20 consecutive patients with AIS were treated with ION corrective spinal surgery. Both qualitative and quantitative analysis was performed with real-time modifications. Operating time, scan time, dose length product (measure of CT radiation exposure), use of fluoroscopy, the influence of the reference frame, blood loss, and neuromonitoring were assessed. RESULTS: The greatest gains in productivity were in avoiding repeat intraoperative scans (a mean of 248 minutes for patients who had two scans, and a mean 180 minutes for those who had a single scan). Optimizing accuracy was the biggest factor influencing this, which was reliant on incremental changes to the operating setup and technique. CONCLUSION: The application of lean principles to the introduction of ION for AIS surgery helps assimilate this method into the environment of the operating theatre. Data and stakeholder analysis identified a reproducible technique for using ION for AIS surgery, reducing operating time, and radiation exposure. Cite this article: Bone Joint J. 2020;102-B(1):5-10.


Asunto(s)
Neuronavegación/métodos , Escoliosis/cirugía , Adolescente , Pérdida de Sangre Quirúrgica/estadística & datos numéricos , Tornillos Óseos/estadística & datos numéricos , Diseño de Equipo , Femenino , Fluoroscopía/estadística & datos numéricos , Humanos , Cuidados Intraoperatorios/métodos , Masculino , Bloqueantes Neuromusculares/administración & dosificación , Neuronavegación/instrumentación , Tempo Operativo , Posicionamiento del Paciente , Dosis de Radiación , Resultado del Tratamiento
10.
Artículo en Japonés | MEDLINE | ID: mdl-31956183

RESUMEN

PURPOSE: X-ray pelvimetry is typically performed for the diagnosis of the cephalopelvic disproportion (CPD). The purpose of this study was to assess the utility of new computed tomography (CT) reconstruction "deep learning based reconstruction (DLR) " in ultra-low dose CT pelvimetry. METHOD: CT pelvimetry was performed 320-row CT. All CT images were reconstructed with and without DLR and transferred for workstation to processing martius and guthmann view. Radiologist and obstetrician-gynecologist subjectively ranked overall image quality of each CT image from the best to the worst. Exposure dose of the CT pelvimetry used a following calculated value, displayed CT dose index (CTDI) vol multiplied by measured value using the thimble chamber and pelvic phantom, and of the X-ray pelvimetry used Japan-Diagnositic Refernce Levels 2015 as a reference, were compared. RESULT: 3D images obtained from CT pelvimetry with DLR showed accurate biparietal diameter and obstetric conjugate as compared to without DLR. Radiation dose of CT pelvimetry is 0.39 mGy, of X-ray pelvimetry is 1.18 mGy, respectively. Conculusion: Although the visualizing high contrast object, such as bone morphology, is likely to reduce exposure dose in CT examination generally, DLR enable to further dose reduction to keep image quality. 3D image processing from CT pelvimetry solves the problem of expansion rate in X-P pelvimetry and provide accurate measurements. Furthermore, CT pelvimetry can undergo more comfortable position for Pregnant Woman in Labor.


Asunto(s)
Desproporción Cefalopelviana , Aprendizaje Profundo , Pelvimetría , Desproporción Cefalopelviana/diagnóstico por imagen , Femenino , Humanos , Japón , Embarazo , Dosis de Radiación , Tomografía Computarizada por Rayos X
11.
Artículo en Japonés | MEDLINE | ID: mdl-31956184

RESUMEN

PURPOSE: The International Commission on Radiological Protection recommended that interventional radiologies (IRs) have high radiation doses and that staff may also be exposed to high doses. In the present study, we measured the radiation exposure dose [3 mm dose equivalent, Hp (3) ] in the eye using an appropriate dosimeter placed next to the physician' s eye during neurovascular intervention procedure (Neuro-IR) and interventional cardiac electrophysiology procedure (EP-IR). METHOD: Physicians wore a direct eye dosemeter just lateral to the left eye and an additional direct eye dosemeter outside the radiation protective glasses close to their left eye. Additionally, a neck badge [0.07 mm dose equivalent, Hp (0.07) ] was worn outside the protective apron to the left of the neck, to compare the direct eye dosimeter estimated doses. The occupational eye lens dose was evaluated over a period of 6-month. RESULTS: The maximum Hp (3) of the Neuro-IR physician was estimated 5.1 mSv without the radiation protective glasses and 1.6 mSv with the radiation protective glasses. On the other hand, the maximum Hp (3) of the EP-IR physician was estimated 29 mSv without the radiation protective glasses and 15 mSv with the radiation protective glasses. CONCLUSION: Physicians eye lens dose [Hp (3) ] tended to be overestimated by the neck badge measurements [Hp (0.07)]. A correct evaluation of the lens dose [Hp (3) ] using the direct eye dosimeter is recommended. Although we found a positive correlation between Hp (0.07) and Hp (3), the value of R2 in the regression equation is low, we recommended that the eye lens dose estimated carefully from Hp (0.07).


Asunto(s)
Técnicas Electrofisiológicas Cardíacas , Cristalino , Exposición Profesional , Exposición a la Radiación , Protección Radiológica , Humanos , Cristalino/efectos de la radiación , Exposición Profesional/prevención & control , Dosis de Radiación , Radiología Intervencional
12.
Artículo en Japonés | MEDLINE | ID: mdl-31956187

RESUMEN

It is important to reduce the dose received by medical staffs. The purpose of this study was to evaluate the effect of protective curtain and the property of small optically stimulated luminescence (OSL) dosimeters used for ambient dose measurement in fluoroscopy. The property of small OSL dosimeters was investigated in terms of uniformity, changing fluoroscopy time and polymethyl methacrylate (PMMA) thickness, and angular dependence. Paper pipes were assembled in glid shape and ambient dose was investigated by using small OSL dosimeters that were put on them with and without protective curtain. Air kerma was investigated by small OSL dosimeters that were put on a head phantom at the position of eyes. Dose response of small OSL dosimeters was independent of fluoroscopy time and PMMA thickness, so it is appropriate to measure ambient dose by small OSL dosimeters. In relation to ambient dose, there was significant difference with and without protective curtain (p<0.001, paired-t-test). These air kerma on the head phantom were reduced to approximately 20% by attaching protective curtain. In order to reduce the dose received by operators, it is desirable to use protective curtain.


Asunto(s)
Colangiopancreatografia Retrógrada Endoscópica , Dosis de Radiación , Exposición a la Radiación , Protección Radiológica , Humanos , Equipos de Seguridad
13.
Artículo en Japonés | MEDLINE | ID: mdl-31956188

RESUMEN

PURPOSE: It is very important to manage the radiation dose of cardiovascular interventional (CVI) procedures. Overseas, the diagnostic reference levels for cardiac interventional procedures were established with the air kerma at the patient entrance reference point (Ka,r) and the air kerma-area product (PKA). Although the Japan DRLs 2015 was established by the Japan Network for Research and Information on Medical Exposure (J-RIME), the Japan DRL for CVIs were established by fluoroscopic dose rates of 20 mGy/min at the patient entrance reference point with 20 cm thickness polymethyl methacrylate (PMMA) phantom. In the present our study, we performed a questionnaire survey of indicated values of angiographic parameters in CVI procedures. METHODS: A nationwide questionnaire was sent by post to 765 facilities. Question focused on angiographic technology, exposure parameters and radiation doses as the displayed dosimetric parameters on the angiographic machine. RESULTS: The recovery rate was 22.8% at 175 out of 765 facilities. In total 1728 cases of the coronary angiography (CAG), 1703 cases of the percutaneous coronary intervention (PCI), 962 cases of the radiofrequency catheter ablation (RFCA) and 377 cases of pediatric CVI. The 75th percentile value of Ka,r, PKA, fluoroscopy time (FT) and number of cine images (CI) for CAG, PCI, RFCA and pediatric CVI were 702, 2042, 644, and 159 mGy, respectively, 59.3, 152, 81.3, and 14.9 Gy・cm2, respectively, 10.2, 35.6, 61.1, and 35.6 min, respectively and 1503, 2672, 722, and 2378 images, respectively. Our investigation showed that the angiographic parameters were different in several CVI procedures. CONCLUSIONS: The displayed dosimetric parameters on the angiographic machine in CVI procedures showed different values. We should classify the dosimetric parameters for each procedure.


Asunto(s)
Intervención Coronaria Percutánea , Dosis de Radiación , Exposición a la Radiación , Niño , Fluoroscopía , Humanos , Japón , Radiografía Intervencional , Encuestas y Cuestionarios
14.
Artículo en Japonés | MEDLINE | ID: mdl-31956189

RESUMEN

In June 2015, Japanese diagnostic reference levels (Japan DRLs 2015) was released by Japan Network for Research and Information on Medical Exposures (J-RIME). After six months the release of Japan DRLs 2015, we have conducted a questionnaire and received 222 responses from hospital staff regarding their perception level, and implementation on Japan DRLs 2015 at their facilities. 131 people (59.0%) were familiar with Japan DRLs 2015, of which 56 people (29.2%) were not currently implementation of them. A total of 66 people (30.1%) understood how to implement Japan DRLs 2015. There were 35 people (18.2%) who heard of diagnostic reference levels (DRLs) for the first time through this survey. Those are the levels of perception and implementation on Japan DRLs 2015 became clear. It is necessary to compare the dose levels used at each facility with Japan DRLs 2015 to optimize patient protection during medical exposure. It is essential to continue to grow the medical community's understanding of DRLs with the expanded perception and implementation of this survey as an opinion poll across Japan.


Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Exposición a la Radiación , Humanos , Japón , Dosis de Radiación , Valores de Referencia , Encuestas y Cuestionarios
19.
Medicine (Baltimore) ; 99(4): e18485, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31977845

RESUMEN

To assess justification and radiation doses of abdomen-pelvis CT in women of childbearing potential (WOCBP) scanned in 2 tertiary hospitals in Qatar.The local ethical committee approved retrospective study of 451 WOCBP (14-55 years) who underwent abdomen-pelvis CT examinations. Patients' age, clinical indications for ordered CT, scanner types and vendors, number and type of scan phases (non-contrast, arterial, portal venous, and/or delayed phases), and radiation dose descriptors (CT dose index volume - CTDIvol and dose length product- DLP) were recorded. Patients undergoing simultaneous chest-abdomen-pelvis CT were excluded. We classified the clinical indications for all 451 CT into indicated and unindicated based on the ACR Appropriateness Criteria. Information regarding the date of last menstrual period, likelihood of pregnancy, and if available, results of the pregnancy test were recorded. Data were analyzed with descriptive statistics (median and inter-quartile range) and analysis of variance (ANOVA).None of the patients were pregnant at the time of their scanning. Amongst the 673 phases acquired for multiphase abdomen-pelvis CT in 451 patients, the 47% unindicated phases (315/673) included non-contrast (122/673, 18%), arterial (33/673, 5%), portal venous (125/673, 19%) and delayed (35/673, 5%) phases. The respective median DLP for indicated and unindicated phases were 266 and 758 mGy.cm (P < .0001).Multiphase abdomen-pelvis CT exams are frequent but seldom justified in WOCBP. They lead to a substantial increase in unindicated radiation dose compared to a single-phase CT.


Asunto(s)
Radiografía Abdominal/métodos , Tomografía Computarizada por Rayos X/métodos , Adolescente , Adulto , Femenino , Humanos , Persona de Mediana Edad , Dosis de Radiación , Radiografía Abdominal/efectos adversos , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/efectos adversos , Adulto Joven
20.
Int J Radiat Biol ; 96(1): 12-21, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-30373439

RESUMEN

Purpose: The purpose of this research was to demonstrate the impact of accounting for age-based radiation response when estimating radiation casualties in a nuclear detonation scenario.Materials and methods: Three nuclear device detonation scenarios were simulated using densely populated regions to compare traditional casualty estimates with age-dependent casualty estimates. Fatalities were estimated using age-based dose-response curves. The surviving population was assumed injured (requiring medical care) if their dose exceeded a lower bound, represented by the minimum dose required to cause deterministic effects, for each age group.Results: In each of the three scenarios, the affected area increased significantly for radiosensitive age groups. In two of the three scenarios, accounting for age-dependent radiosensitivity resulted in up to a 10% increase in fatalities and up to a 12% increase in radiation injuries compared to traditional estimates. This study demonstrates that the differences in casualty estimates are dependent on the relative density and location of radiosensitive populations.Conclusions: These results demonstrate that the inclusion of age-based demographic data and associated dose responses may result in significantly higher estimates of casualties depending on the location and age of the affected population. This information could be useful for the emergency management planning community.


Asunto(s)
Incidentes con Víctimas en Masa/estadística & datos numéricos , Modelos Estadísticos , Armas Nucleares , Exposición a la Radiación , Adulto , Factores de Edad , Anciano , Niño , Preescolar , Defensa Civil , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Dosis de Radiación , Adulto Joven
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