Effect of staff training on radiation dose in pediatric CT.

Science.gov (United States)

Hojreh, Azadeh; Weber, Michael; Homolka, Peter

2015-08-01

To evaluate the efficacy of staff training on radiation doses applied in pediatric CT scans. Pediatric patient doses from five CT scanners before (1426 scans) and after staff training (2566 scans) were compared statistically. Examinations included cranial CT (CCT), thoracic, abdomen-pelvis, and trunk scans. Dose length products (DLPs) per series were extracted from CT dose reports archived in the PACS. A pooled analysis of non-traumatic scans revealed a statistically significant reduction in the dose for cranial, thoracic, and abdomen/pelvis scans (p0.05). The percentage of scans performed with DLPs exceeding the German DRLs was reduced from 41% to 7% (CCT), 19% to 5% (thorax-CT), from 9% to zero (abdominal-pelvis CT), and 26% to zero (trunk; DRL taken as summed DRLs for thorax plus abdomen-pelvis, reduced by 20% accounting for overlap). Comparison with Austrian DRLs - available only for CCT and thorax CT - showed a reduction from 21% to 3% (CCT), and 15 to 2% (thorax CT). Staff training together with application of DRLs provide an efficient approach for optimizing radiation dose in pediatric CT practice. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Doses from pediatric CT examinations in Norway: are pediatric scan protocols developed and in daily use?

International Nuclear Information System (INIS)

Friberg, Eva G.

2008-01-01

Doses to pediatric patients from CT examinations are known to be unnecessarily high if scan protocols developed for adult patients are adopted. This overexposure is most often not recognized by the operating radiographer, due to the digital behavior of the imaging system. Use of optimized size-specific pediatric scan protocols is therefore essential to keep the doses at an appropriate level. The aim of this study was to investigate the doses to pediatric patients from CT examinations and to evaluate the level of optimization of the scan protocols. Patient data, applied scan parameters together with the dose parameters volume computed tomography dose index (CTD vol ) and dose length product (DLP) for examinations of the head, chest and abdomen were collected by means of a questionnaire from five university hospitals. The effective dose was estimated from the total DLP by use of region-specific conversion coefficients (E DLP ). Totally 136, 108 and 82 questionnaires were received for examinations of the head, chest and abdomen, respectively. Large variations in patient doses between the hospitals were observed, addressing the need for optimization of the scan protocols in general. Most of the hospitals applied successive lower mAs with decreasing patient age for all scan areas, while the use of lower tube voltage for small patients and a higher tube voltage for large patients were more rarely. This indicates the presence, to a certain level, of size specific scan protocols at some Norwegian hospitals. Focus on developing size-specific scan protocols for pediatric patients are important to reduce the doses and risks associated with pediatric CT examinations. (author)

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... information about radiation dose. There always is a risk of complications from general anesthesia or sedation. Every measure will be taken to ... in X-Ray and CT Exams Contrast Materials Anesthesia Safety Children and Radiation Safety ... (Pediatric) CT (Computed Tomography) Videos related to Children's (Pediatric) ...

Radiation dose reduction in pediatric CT

International Nuclear Information System (INIS)

Robinson, A.E.; Hill, E.P.; Harpen, M.D.

1986-01-01

The relationship between image noise and radiation dose was investigated in computed tomography (CT) images of a pediatric abdomen phantom. A protocol which provided a minimum absorbed dose consistent with acceptable image noise criteria was determined for a fourth generation CT scanner. It was found that pediatric abdominal CT scans could maintain diagnostic quality with at least a 50% reduction in dose from the manufacturers' suggested protocol. (orig.)

The development of a population of 4D pediatric XCAT phantoms for CT imaging research and optimization

Science.gov (United States)

Norris, Hannah; Zhang, Yakun; Frush, Jack; Sturgeon, Gregory M.; Minhas, Anum; Tward, Daniel J.; Ratnanather, J. Tilak; Miller, M. I.; Frush, Donald; Samei, Ehsan; Segars, W. Paul

2014-03-01

With the increased use of CT examinations, the associated radiation dose has become a large concern, especially for pediatrics. Much research has focused on reducing radiation dose through new scanning and reconstruction methods. Computational phantoms provide an effective and efficient means for evaluating image quality, patient-specific dose, and organ-specific dose in CT. We previously developed a set of highly-detailed 4D reference pediatric XCAT phantoms at ages of newborn, 1, 5, 10, and 15 years with organ and tissues masses matched to ICRP Publication 89 values. We now extend this reference set to a series of 64 pediatric phantoms of a variety of ages and height and weight percentiles, representative of the public at large. High resolution PET-CT data was reviewed by a practicing experienced radiologist for anatomic regularity and was then segmented with manual and semi-automatic methods to form a target model. A Multi-Channel Large Deformation Diffeomorphic Metric Mapping (MC-LDDMM) algorithm was used to calculate the transform from the best age matching pediatric reference phantom to the patient target. The transform was used to complete the target, filling in the non-segmented structures and defining models for the cardiac and respiratory motions. The complete phantoms, consisting of thousands of structures, were then manually inspected for anatomical accuracy. 3D CT data was simulated from the phantoms to demonstrate their ability to generate realistic, patient quality imaging data. The population of pediatric phantoms developed in this work provides a vital tool to investigate dose reduction techniques in 3D and 4D pediatric CT.

Dose reduction and image quality optimizations in CT of pediatric and adult patients: phantom studies

International Nuclear Information System (INIS)

Jeon, P-H; Lee, C-L; Kim, D-H; Lee, Y-J; Kim, H-J; Jeon, S-S

2014-01-01

Multi-detector computed tomography (MDCT) can be used to easily and rapidly perform numerous acquisitions, possibly leading to a marked increase in the radiation dose to individual patients. Technical options dedicated to automatically adjusting the acquisition parameters according to the patient's size are of specific interest in pediatric radiology. A constant tube potential reduction can be achieved for adults and children, while maintaining a constant detector energy fluence. To evaluate radiation dose, the weighted CT dose index (CTDIw) was calculated based on the CT dose index (CTDI) measured using an ion chamber, and image noise and image contrast were measured from a scanned image to evaluate image quality. The dose-weighted contrast-to-noise ratio (CNRD) was calculated from the radiation dose, image noise, and image contrast measured from a scanned image. The noise derivative (ND) is a quality index for dose efficiency. X-ray spectra with tube voltages ranging from 80 to 140 kVp were used to compute the average photon energy. Image contrast and the corresponding contrast-to-noise ratio (CNR) were determined for lesions of soft tissue, muscle, bone, and iodine relative to a uniform water background, as the iodine contrast increases at lower energy (i.e., k-edge of iodine is 33 keV closer to the beam energy) using mixed water-iodine contrast normalization (water 0, iodine 25, 100, 200, and 1000 HU, respectively). The proposed values correspond to high quality images and can be reduced if only high-contrast organs are assessed. The potential benefit of lowering the tube voltage is an improved CNRD, resulting in a lower radiation dose and optimization of image quality. Adjusting the tube potential in abdominal CT would be useful in current pediatric radiography, where the choice of X-ray techniques generally takes into account the size of the patient as well as the need to balance the conflicting requirements of diagnostic image quality and radiation dose

Dose optimization in CT examination of children

International Nuclear Information System (INIS)

Hojreh, A.; Prosch, H.

2012-01-01

Problems arise due to the increased clinical use of computed tomography (CT) and the high radiosensitivity of children. The ALARA concept (as low as reasonably achievable) prevails in pediatric radiology. Justified indications and full utilization of available dose optimization methods. Medical physicists and the manufacturers should support pediatric radiology in the implementation of the ALARA concept. The referring physicians and radiology staff should be integrated into training programs. Sufficient diagnostic image quality is paramount and not the pretty images. (orig.) [de

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... in CT scans should have no immediate side effects. Risks The risk of serious allergic reaction to ... Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... your child. top of page Additional Information and Resources The Alliance for Radiation Safety in Pediatric Imaging's " ... A child being prepared for a CT scan. View full size with caption Pediatric Content Some imaging ...

Is It Better to Enter a Volume CT Dose Index Value before or after Scan Range Adjustment for Radiation Dose Optimization of Pediatric Cardiothoracic CT with Tube Current Modulation?

Science.gov (United States)

2018-01-01

Objective To determine whether the body size-adapted volume computed tomography (CT) dose index (CTDvol) in pediatric cardiothoracic CT with tube current modulation is better to be entered before or after scan range adjustment for radiation dose optimization. Materials and Methods In 83 patients, cardiothoracic CT with tube current modulation was performed with the body size-adapted CTDIvol entered after (group 1, n = 42) or before (group 2, n = 41) scan range adjustment. Patient-related, radiation dose, and image quality parameters were compared and correlated between the two groups. Results The CTDIvol after the CT scan in group 1 was significantly higher than that in group 2 (1.7 ± 0.1 mGy vs. 1.4 ± 0.3 mGy; p Hounsfield units [HU] vs. 4.5 ± 0.7 HU) and image quality (1.5 ± 0.6 vs. 1.5 ± 0.6) showed no significant differences between the two (p > 0.05). In both groups, all patient-related parameters, except body density, showed positive correlations (r = 0.49–0.94; p 0.05) in group 2. Conclusion In pediatric cardiothoracic CT with tube current modulation, the CTDIvol entered before scan range adjustment provides a significant dose reduction (18%) with comparable image quality compared with that entered after scan range adjustment.

Dual-energy compared to single-energy CT in pediatric imaging: a phantom study for DECT clinical guidance

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Zhu, Xiaowei; Servaes, Sabah; Darge, Kassa [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); University of Pennsylvania, The Perelman School of Medicine, Philadelphia, PA (United States); McCullough, William P. [University of Virginia Health System, Department of Radiology and Medical Imaging, Charlottesville, VA (United States); Mecca, Patricia [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States)

2016-11-15

Dual-energy CT technology is available on scanners from several vendors and offers significant advantages over classic single-energy CT technology in multiple clinical applications. Many studies have detailed dual-energy CT applications in adults and several have evaluated the relative radiation dose performance of dual-energy CT in adult imaging. However, little has been published on dual-energy CT imaging in the pediatric population, and the relative dose performance of dual-energy CT imaging in the pediatric population is not well described. When evaluating dual-energy CT technology for implementation into a routine clinical pediatric imaging practice, the radiation dose implications must be considered, and when comparing relative CT dose performance, image quality must also be evaluated. Therefore the purpose of this study is to develop dual-energy CT scan protocols based on our optimized single-energy scan protocols and compare the dose. We scanned the head, chest and abdomen regions of pediatric-size anthropomorphic phantoms with contrast inserts, using our optimized single-energy clinical imaging protocols on a Siemens Flash {sup registered} CT scanner. We then scanned the phantoms in dual-energy mode using matching image-quality reference settings. The effective CT dose index volume (CTDI{sub vol}) of the scans was used as a surrogate for relative dose in comparing the single- and dual-energy scans. Additionally, we evaluated image quality using visual assessment and contrast-to-noise ratio. Dual-energy CT scans of the head and abdomen were dose-neutral for all three phantoms. Dual-energy CT scans of the chest showed a relative dose increase over the single-energy scan for 1- and 5-year-old child-based age-equivalent phantoms, ranging 11-20%. Quantitative analysis of image quality showed no statistically significant difference in image quality between the single-energy and dual-energy scans. There was no clinically significant difference in image quality by

Patient doses in CT with special emphasis on pediatric patients in Algeria

International Nuclear Information System (INIS)

Khelassi-Toutaoui, Nadia; Merad, Ahmed; Toutaoui, Aek; Bairi, Souad; Tsapaki, Virginia; Mansouri, Boudjema

2008-01-01

Full text: Purpose: To estimate the frequency of CT examinations in children 0-15 years of age, to investigate whether exposure factors for children are different than for adults and to evaluate patient dose, as part of an International Atomic Energy Agency (IAEA) project on Radiation Protection of patients and Medical Exposure Control (RAF 9033). Material and Methods: Two CT machines were included in the study. Weighted computed tomography dose index (CTDI w ). Results: Pediatric CT examinations accoutered for 12-20% of the total exams performed in the CT facilities. For head, chest and abdomen examinations, mAs were reduced for pediatric patients, mainly on an arbitrary manner. One of the CT machines allowed change of kV and in that case kV was reduced for pediatric patients. Chest, Chest-High Resolution, Abdomen, Lumbar spine and Pelvis CTDI w and DLP were lower and IAEA guidance levels in almost all types of exams. It was observed, however, that DLP in one hospital was almost double than the other hospital that was mostly attributed to larger extent of scan length. ) for a single slice and dose length product (DLP) for a complete examination were used to evaluate patient dose. Kilovoltage (kV) and mAs were the exposure factors investigated. Conclusion: The study showed that pediatric examinations reach up to 1/5 of the total exams performed. It is encouraging that exposure factors are reduced, but a more standard method of reduction should be applied. Patient doses were lower that IAEA standards. Further optimization could be done by reducing scan length. (author)

Optimizing the balance between radiation dose and image quality in pediatric head CT: findings before and after intensive radiologic staff training.

Science.gov (United States)

Paolicchi, Fabio; Faggioni, Lorenzo; Bastiani, Luca; Molinaro, Sabrina; Puglioli, Michele; Caramella, Davide; Bartolozzi, Carlo

2014-06-01

The purpose of this study was to assess the radiation dose and image quality of pediatric head CT examinations before and after radiologic staff training. Outpatients 1 month to 14 years old underwent 215 unenhanced head CT examinations before and after intensive training of staff radiologists and technologists in optimization of CT technique. Patients were divided into three age groups (0-4, 5-9, and 10-14 years), and CT dose index, dose-length product, tube voltage, and tube current-rotation time product values before and after training were retrieved from the hospital PACS. Gray matter conspicuity and contrast-to-noise ratio before and after training were calculated, and subjective image quality in terms of artifacts, gray-white matter differentiation, noise, visualization of posterior fossa structures, and need for repeat CT examination was visually evaluated by three neuroradiologists. The median CT dose index and dose-length product values were significantly lower after than before training in all age groups (27 mGy and 338 mGy ∙ cm vs 107 mGy and 1444 mGy ∙ cm in the 0- to 4-year-old group, 41 mGy and 483 mGy ∙ cm vs 68 mGy and 976 mGy ∙ cm in the 5- to 9-year-old group, and 51 mGy and 679 mGy ∙ cm vs 107 mGy and 1480 mGy ∙ cm in the 10- to 14-year-old group; p training were significantly lower than the levels before training (p staff training can be effective in reducing radiation dose while preserving diagnostic image quality in pediatric head CT examinations.

Dual-energy compared to single-energy CT in pediatric imaging: a phantom study for DECT clinical guidance

International Nuclear Information System (INIS)

Zhu, Xiaowei; Servaes, Sabah; Darge, Kassa; McCullough, William P.; Mecca, Patricia

2016-01-01

Dual-energy CT technology is available on scanners from several vendors and offers significant advantages over classic single-energy CT technology in multiple clinical applications. Many studies have detailed dual-energy CT applications in adults and several have evaluated the relative radiation dose performance of dual-energy CT in adult imaging. However, little has been published on dual-energy CT imaging in the pediatric population, and the relative dose performance of dual-energy CT imaging in the pediatric population is not well described. When evaluating dual-energy CT technology for implementation into a routine clinical pediatric imaging practice, the radiation dose implications must be considered, and when comparing relative CT dose performance, image quality must also be evaluated. Therefore the purpose of this study is to develop dual-energy CT scan protocols based on our optimized single-energy scan protocols and compare the dose. We scanned the head, chest and abdomen regions of pediatric-size anthropomorphic phantoms with contrast inserts, using our optimized single-energy clinical imaging protocols on a Siemens Flash "r"e"g"i"s"t"e"r"e"d CT scanner. We then scanned the phantoms in dual-energy mode using matching image-quality reference settings. The effective CT dose index volume (CTDI_v_o_l) of the scans was used as a surrogate for relative dose in comparing the single- and dual-energy scans. Additionally, we evaluated image quality using visual assessment and contrast-to-noise ratio. Dual-energy CT scans of the head and abdomen were dose-neutral for all three phantoms. Dual-energy CT scans of the chest showed a relative dose increase over the single-energy scan for 1- and 5-year-old child-based age-equivalent phantoms, ranging 11-20%. Quantitative analysis of image quality showed no statistically significant difference in image quality between the single-energy and dual-energy scans. There was no clinically significant difference in image quality

Evaluation of doses received by pediatric and adult patients undergoing to CT exams

International Nuclear Information System (INIS)

Lavie, Maria F. Jimenez; Tejeda, Adalberto Machado; Otano, Anisia; Zuniga, Dora Maya; Perdomo, Jorge Hing; Rodriguez, Gustavo Guadarrama

2013-01-01

This paper aims to evaluated the dose to adult and pediatric patients due to the execution of tests CT scan of head, chest and abdomen, as well as establish a comparative analysis between these results and protocols involving employees to begin a process optimization in the practice

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... CT scans that are not clearly needed. Another strategy is to consider other tests, such as MRI ... for Radiation Safety in Pediatric Imaging's "Image Gently" Campaign top of page This page was reviewed on ...

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Adapting protocols of CT imaging in a pediatric emergency department. Evaluation of image quality and dose

International Nuclear Information System (INIS)

Batista Arce, A.; Gonzalez Lopez, S.; Catalan Acosta, A.; Casares Magaz, O.; Hernandez Armas, O.; Hernandez Armas, J.

2011-01-01

The purpose of this study was to assess qualitatively the picture quality in relation to the radiation dose delivered in CT studies of computer tomograph Pediatric Emergency Department of Hospital Universitario de Canarias (HUC) in order to optimize the technical parameters used these radiological examinations so as to obtain optimal image quality at the lowest possible dose.

Clinical application of ‘Justification’ and ‘Optimization’ principle of ALARA in pediatric CT imaging: “How many children can be protected from unnecessary radiation?”

International Nuclear Information System (INIS)

Sodhi, Kushaljit S.; Krishna, Satheesh; Saxena, Akshay K.; Sinha, Anindita; Khandelwal, Niranjan; Lee, Edward Y.

2015-01-01

Highlights: • Practice of ALARA (As Low As Reasonably Achievable) principle in the developed world is currently well established. However, there is striking lack of published data regarding such experience in the developing countries. Therefore, the goal of this study is to prospectively evaluate CT request forms to assess how many children could be saved from harmful radiation exposure if ‘Justification’ and ‘Optimization’ principles of ALARA are applied before obtaining CT imaging in a developing country. • A consecutive 1302 CT request forms over a six month study period (May 16, 2013 to November 15, 2013) in a tertiary pediatric children’s hospital in India were prospectively reviewed by two pediatric radiologists before obtaining CT imaging. First, ‘Justification’ of CT was evaluated and then ‘Optimization’ was applied for evaluation of appropriateness of the requested CT studies. The number (and percentage) of CT studies that was avoided by applying ‘Justification’ and ‘Optimization’ principle of ALARA were calculated. The difference in number of declined and optimized CT requests between CT requests from inpatient and outpatient departments was compared using Chi-Square test. • Based on evaluation of the CT request forms for ‘Justification’ and ‘Optimization’ principle of ALARA by pediatric radiology reviewers, 111 individual anatomic part CT requests from 105 pediatric patients were avoided. Therefore, 8.06% (105 out of 1302 pediatric patients) were saved from unnecessary or additional radiation exposure The rates of declined or optimized CT requests from inpatient department was significantly higher than that from outpatient departments (p < 0.05). • To conclude, a substantial number of pediatric patients, particularly coming from inpatients departments, can be saved from unnecessary or additional radiation exposure from CT imaging when ‘Justification’ and ‘Optimization’ principle of ALARA are applied

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us ... or better than those obtained by CT scanning. Working together, your primary care physician or ... Safety in Pediatric Imaging's "Image Gently" Campaign top of ...

KERMA ratios in pediatric CT dosimetry

International Nuclear Information System (INIS)

Huda, Walter; Ogden, Kent M.; Lavallee, Robert L.; Roskopf, Marsha L.; Scalzetti, Ernest M.

2012-01-01

Patient organ doses may be estimated from CTDI values. More accurate estimates may be obtained by measuring KERMA (Kinetic Energy Released in Matter) in anthropomorphic phantoms and referencing these values to free-in-air X-ray intensity. To measure KERMA ratios (R K ) in pediatric phantoms at CT. CT scans produce an air KERMA K in a phantom and an air KERMA K CT at isocenter. KERMA ratios (R K ) are defined as (K/K CT ), measured using TLD chips in phantoms representing newborns to 10-year-olds. R K in the newborn is approximately constant. For the other phantoms, there is a peak R K value in the neck. The median R K values for the GE scanner at 120 kV were 0.92, 0.83, 0.77 and 0.76 for newborns, 1-year-olds, 5-year-olds and 10-year-olds, respectively. Organ R K values were 0.91 ± 0.04, 0.84 ± 0.07, 0.74 ± 0.09 and 0.72 ± 0.10 in newborns, 1-year-olds, 5-year-olds and 10-year-olds, respectively. At 120 kV, a Siemens Sensation 16 scanner had R K values 5% higher than those of the GE LightSpeed Ultra. KERMA ratios may be combined with air KERMA measurements at the isocenter to estimate organ doses in pediatric CT patients. (orig.)

CT scanning in pediatric head trauma: correlation of clinical features with CT scan diagnosis

International Nuclear Information System (INIS)

Arkoncel, Mary Ann P.; Posadas, Ma. Belen A.

1997-01-01

A retrospective review was conducted on 205 cases of pediatric head trauma for which cranial computed tomography scans were done at the Makati Medical Center, to determine which clinical features might positively predict an abnormality on CT scan. The clinical findings of loss of consciousness, GCS < 12, vomiting headache, seizures, and focal abnormalities on Neurologic Examination were significantly associated with abnormal findings on CT scan. However, a significant discrepancy does exist as to how accurately clinical findings do in fact predict normal and abnormal CT scan findings. Such a discrepancy allows us to conclude that a more liberal use of CT Scanning in cases of pediatric head trauma must be stressed to insure proper diagnosis. This study shows that when a patient presents with the aforementioned positive signs and symptoms, or with a focal neurologic deficit, or in combination, a 60-100 % positive prediction of abnormal CT Scan can be made. However, prediction of normal CT Scan is only 0-40%. (Author)

Protocol optimization in chest CT scans of child

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Abrao L, L. T.; Amaral de O, F.; Prata M, A. [Biomedical Engineering Center, Centro Federal de Educacao Tecnologica de Minas Gerais, 30421-169, Belo Horizonte, Minas Gerais (Brazil); Bustos F, M., E-mail: luanaabrao@gmail.com [Universidad Federal de Minas Gerais, Department of Nuclear Engineering, Av. Pres. Antonio Carlos 6627, Pampulha, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

2017-10-15

The dissemination of Computed Tomography (CT), a radiodiagnostic technique, has significant increase in the patient dose. In the last years, this technique has shown a high growth due to clinical cases of medical emergencies, neoplasm and pediatric traumas. Dose measurement is important to correlate with the deleterious effects of radiation on the organism and radiation future effects is related with stochastic risks due to tissue radiosensitivity, allied to the life expectancy of the child. In this work, a cylindrical phantom, representing an adult chest made of polymethylmethacrylate (PMMA), was used and a new born chest phantom with a shape oblong was developed based on the dimensions of a typical newborn. In a Ge CT scanner, Discovery model, with 64 channels, the central slice of the phantoms were irradiated successively in order to obtain dose measurements using an ionizing pencil camera. Based in the measurements, dose index was calculated (CTDI{sub vol}). The radiological service chest protocol using a voltage of 120 kV was used for scanning 10 cm of the central area of the adult and newborn phantom, in helical mode. An acquisition of images was performed using this radiological service chest protocol to compare with the protocol optimized. In the newborn phantom was also used protocols optimized using a voltage of 120 and 80 kV. The voltage of 80 kV has the lowest dose index for the pediatric object phantom. This work allowed the comparison between absorbed dose variations by the pediatric phantom changing the X-ray tube supply voltage. This dose variation has shown how important is specific protocols for children. (Author)

Protocol optimization in chest CT scans of child

International Nuclear Information System (INIS)

Abrao L, L. T.; Amaral de O, F.; Prata M, A.; Bustos F, M.

2017-10-01

The dissemination of Computed Tomography (CT), a radiodiagnostic technique, has significant increase in the patient dose. In the last years, this technique has shown a high growth due to clinical cases of medical emergencies, neoplasm and pediatric traumas. Dose measurement is important to correlate with the deleterious effects of radiation on the organism and radiation future effects is related with stochastic risks due to tissue radiosensitivity, allied to the life expectancy of the child. In this work, a cylindrical phantom, representing an adult chest made of polymethylmethacrylate (PMMA), was used and a new born chest phantom with a shape oblong was developed based on the dimensions of a typical newborn. In a Ge CT scanner, Discovery model, with 64 channels, the central slice of the phantoms were irradiated successively in order to obtain dose measurements using an ionizing pencil camera. Based in the measurements, dose index was calculated (CTDI vol ). The radiological service chest protocol using a voltage of 120 kV was used for scanning 10 cm of the central area of the adult and newborn phantom, in helical mode. An acquisition of images was performed using this radiological service chest protocol to compare with the protocol optimized. In the newborn phantom was also used protocols optimized using a voltage of 120 and 80 kV. The voltage of 80 kV has the lowest dose index for the pediatric object phantom. This work allowed the comparison between absorbed dose variations by the pediatric phantom changing the X-ray tube supply voltage. This dose variation has shown how important is specific protocols for children. (Author)

Chest CT findings in pediatric Wegener's granulomatosis

International Nuclear Information System (INIS)

Levine, Daniel; Akikusa, Jonathan; Manson, David; Silverman, Earl; Schneider, Rayfel

2007-01-01

Although pulmonary involvement occurs in the majority of children and adolescents with Wegener's granulomatosis (WG), relatively little has been published regarding the CT imaging manifestations in this group of patients. To determine the frequency and types of chest CT abnormalities in active pediatric WG (pWG). The study was a retrospective examination of 29 chest CT examinations performed at diagnosis (n=14) and during disease flares (n=15) in 18 children. The most common abnormalities were nodules (seen in 90% of examinations), ground-glass opacification (52%), and air-space opacification (45%). Of examinations with nodules, 73% demonstrated nodules >5 mm in diameter and 69% demonstrated more than five nodules; 17% had cavitary lesions. The only abnormality with a significant difference in prevalence between diagnosis and disease flares was air-space opacification, present in 71% and 20%, respectively (P < 0.01). In accordance with the findings of published adult studies and at variance with those of prior pediatric studies, our findings indicate that chest CT abnormalities in active pWG are frequent, most commonly comprising nodules and ground-glass opacification, which may be difficult to detect on plain radiography. We therefore advocate the routine use of chest CT for all affected patients, both at the time of presentation and during disease flares. (orig.)

The optimal parameter for radiation dose in pediatric low dose abdominal CT: cross-sectional dimensions versus body weight

International Nuclear Information System (INIS)

Jung, Yoon Young; Goo, Hyun Woo

2008-01-01

To investigate the best parameter between cross-sectional dimensions and body weight in pediatric low dose abdominal CT. One hundred and thirty six children consecutively underwent weight-based abdominal CT. The subjects consisted of group 1 (79 children, weight range 10.0-19.9 kg) and group 2 (57 children, weight range 20.0-39.9 kg). Abdominal cross-sectional dimensions including circumference, area, anteroposterior diameters and transverse diameters were calculated. Image noise (standard deviation of CT density) was measured by placing a region of interest in the posterior segment of the right hepatic lobe on a CT image at the celiac axis. The measured image noise was correlated with the cross-sectional abdominal dimensions and body weight for subjects in each group. In group 1 subjects,area, circumference, transverse diameter, anteroposterior diameter, and body weight showed a significant positive correlation with image noise in descending order(γ = 0.63, 0.62, 0.61, 0.51, and 0.49; ρ < 0.0001). In group 2 subjects, transverse diameter, circumference, area, anteroposterior diameter, and body weight showed a significant positive correlation with image noise in descending order (γ = 0.83, 0.82, 0.78, 0.71, and 0.71; ρ < 0.0001). Cross-sectional dimensions such as area, circumference, and transverse diameter showed a higher positive correlation with image noise than body weight for pediatric low dose abdominal CT

SU-E-J-113: The Influence of Optimizing Pediatric CT Simulator Protocols On the Treatment Dose Calculation in Radiotherapy

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Zhang, Y; Zhang, J; Hu, Q; Tie, J; Wu, H [Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Radiotherapy, Peking University Cancer Hospital ' Institute, Beijing (China); Deng, J [Department of Therapeutic Radiology, Yale University, New Haven, CT (United States)

2014-06-01

Purpose: To investigate the possibility of applying optimized scanning protocols for pediatric CT simulation by quantifying the dosimetric inaccuracy introduced by using a fixed HU to density conversion. Methods: The images of a CIRS electron density reference phantom (Model 062) were acquired by a Siemens CT simulator (Sensation Open) using the following settings of tube voltage and beam current: 120 kV/190mA (the reference protocol used to calibrate CT for our treatment planning system (TPS)); Fixed 190mA combined with all available kV: 80, 100, and 140; fixed 120 kV and various current from 37 to 444 mA (scanner extremes) with interval of 30 mA. To avoid the HU uncertainty of point sampling in the various inserts of known electron densities, the mean CT numbers of the central cylindrical volume were calculated using DICOMan software. The doses per 100 MU to the reference point (SAD=100cm, Depth=10cm, Field=10X10cm, 6MV photon beam) in a virtual cubic phantom (30X30X30cm) were calculated using Eclipse TPS (calculation model: AcurosXB-11031) by assigning the CT numbers to HU of typical materials acquired by various protocols. Results: For the inserts of densities less than muscle, CT number fluctuations of all protocols were within the tolerance of 10 HU as accepted by AAPM-TG66. For more condensed materials, fixed kV yielded stable HU with any mA combination where largest disparities were found in 1750mg/cc insert: HU{sub reference}=1801(106.6cGy), HU{sub minimum}=1799 (106.6cGy, error{sub dose}=0.00%), HU{sub maximum}=1815 (106.8cGy, error{sub dose}=0.19%). Yet greater disagreements were observed with increasing density when kV was modified: HU{sub minimum}=1646 (104.5cGy, error{sub dose}=- 1.97%), HU{sub maximum}=2487 (116.4cGy, error{sub dose}=9.19%) in 1750mg/cc insert. Conclusion: Without affecting treatment dose calculation, personalized mA optimization of CT simulator can be conducted by fixing kV for a better cost-effectiveness of imaging dose and quality

Clinical significance of pulmonary nodules detected on abdominal CT in pediatric patients

International Nuclear Information System (INIS)

Breen, Micheal; Lee, Edward Y.; Zurakowski, David

2015-01-01

The clinical significance of a pulmonary nodule that is detected incidentally on CT studies in children is unknown. In addition, there is limited information regarding the management of incidentally detected pulmonary nodules discovered on abdominal CT studies in children. The purpose of this study was to investigate the clinical significance of incidental pulmonary nodules detected on abdominal CT studies in children. This was a retrospective study performed following institutional review board approval. Abdominal CT reports in patients younger than 18 years of age from July 2004 to June 2011 were reviewed for the terms ''nodule,'' ''nodular'' or ''mass'' in reference to the lung bases. The study population included those pediatric patients in whom pulmonary nodules were initially detected on abdominal CT studies. The largest pulmonary nodules detected on CT studies were evaluated for their features (size, shape, margin, attenuation, location, and presence of calcification and cavitation). Follow-up CT studies and clinical records were reviewed for demographic information, history of underlying malignancies and the clinical outcome of the incidental pulmonary nodules. Comparison of malignant versus benign pulmonary nodules was performed with respect to the size of the nodule, imaging features on CT, and patient history of malignancy using the Student's t-test and Fisher exact test. Youden J-index in receiver operating characteristic (ROC) analysis was used to determine the optimal cut-off size for suggesting a high risk of malignancy of incidentally detected pulmonary nodules. Pulmonary nodules meeting inclusion criteria were detected in 62 (1.2%) of 5,234 patients. The mean age of patients with nodules was 11.2 years (range: 5 months-18 years). Thirty-one patients (50%) had follow-up CT studies and two of these patients (6%) were subsequently found to have malignant pulmonary nodules. Both of these

Clinical significance of pulmonary nodules detected on abdominal CT in pediatric patients

Energy Technology Data Exchange (ETDEWEB)

Breen, Micheal; Lee, Edward Y. [Boston Children' s Hospital and Harvard Medical School, Department of Radiology, Boston, MA (United States); Zurakowski, David [Boston Children' s Hospital and Harvard Medical School, Departments of Anesthesiology and Surgery, Boston, MA (United States)

2015-11-15

The clinical significance of a pulmonary nodule that is detected incidentally on CT studies in children is unknown. In addition, there is limited information regarding the management of incidentally detected pulmonary nodules discovered on abdominal CT studies in children. The purpose of this study was to investigate the clinical significance of incidental pulmonary nodules detected on abdominal CT studies in children. This was a retrospective study performed following institutional review board approval. Abdominal CT reports in patients younger than 18 years of age from July 2004 to June 2011 were reviewed for the terms ''nodule,'' ''nodular'' or ''mass'' in reference to the lung bases. The study population included those pediatric patients in whom pulmonary nodules were initially detected on abdominal CT studies. The largest pulmonary nodules detected on CT studies were evaluated for their features (size, shape, margin, attenuation, location, and presence of calcification and cavitation). Follow-up CT studies and clinical records were reviewed for demographic information, history of underlying malignancies and the clinical outcome of the incidental pulmonary nodules. Comparison of malignant versus benign pulmonary nodules was performed with respect to the size of the nodule, imaging features on CT, and patient history of malignancy using the Student's t-test and Fisher exact test. Youden J-index in receiver operating characteristic (ROC) analysis was used to determine the optimal cut-off size for suggesting a high risk of malignancy of incidentally detected pulmonary nodules. Pulmonary nodules meeting inclusion criteria were detected in 62 (1.2%) of 5,234 patients. The mean age of patients with nodules was 11.2 years (range: 5 months-18 years). Thirty-one patients (50%) had follow-up CT studies and two of these patients (6%) were subsequently found to have malignant pulmonary nodules. Both of these

Pediatric CT angiography

International Nuclear Information System (INIS)

Siegel, M.J.

2005-01-01

Advances in CT technology are having profound impact on imaging children and have made CT angiography possible even in neonates. Even with the tiny anatomy of neonates, small volumes of contrast material, and small venous access catheters, successful CT angiography can be performed with attention to detail. Meticulous attention to patient preparation, the proper selection of technical factors, and optimal delivery of contrast material are crucial. Data post-processing and the creation of 3-D reconstructions are also essential in establishing a correct diagnosis. The applications fo CT angiography are different in children than in adults and most applications in children involve assessment of congenital and postoperative vascular and cardiac diseases. The use of CT angiography offers the opportunity to eliminate the long periods of sedation associated with MR and reduce the radiation exposure associated with conventional angiography. Generally, the benefits of CT angiography in children outweigh the risk, namely that of radiation exposure. However, care must still be taken to minimize the radiation exposure. (orig.)

CT of Normal Developmental and Variant Anatomy of the Pediatric Skull: Distinguishing Trauma from Normality.

Science.gov (United States)

Idriz, Sanjin; Patel, Jaymin H; Ameli Renani, Seyed; Allan, Rosemary; Vlahos, Ioannis

2015-01-01

The use of computed tomography (CT) in clinical practice has been increasing rapidly, with the number of CT examinations performed in adults and children rising by 10% per year in England. Because the radiology community strives to reduce the radiation dose associated with pediatric examinations, external factors, including guidelines for pediatric head injury, are raising expectations for use of cranial CT in the pediatric population. Thus, radiologists are increasingly likely to encounter pediatric head CT examinations in daily practice. The variable appearance of cranial sutures at different ages can be confusing for inexperienced readers of radiologic images. The evolution of multidetector CT with thin-section acquisition increases the clarity of some of these sutures, which may be misinterpreted as fractures. Familiarity with the normal anatomy of the pediatric skull, how it changes with age, and normal variants can assist in translating the increased resolution of multidetector CT into more accurate detection of fractures and confident determination of normality, thereby reducing prolonged hospitalization of children with normal developmental structures that have been misinterpreted as fractures. More important, the potential morbidity and mortality related to false-negative interpretation of fractures as normal sutures may be avoided. The authors describe the normal anatomy of all standard pediatric sutures, common variants, and sutural mimics, thereby providing an accurate and safe framework for CT evaluation of skull trauma in pediatric patients. (©)RSNA, 2015.

FDG PET/CT appearance of local osteosarcoma recurrences in pediatric patients

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Sharp, Susan E.; Gelfand, Michael J. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Shulkin, Barry L.; McCarville, M.B. [St. Jude Children' s Research Hospital, Department of Diagnostic Imaging, Memphis, TN (United States)

2017-12-15

Osteosarcoma is the most common pediatric malignant bone tumor, frequently surgically managed with limb salvage rather than amputation. Local recurrences are seen in up to 9% of osteosarcoma patients, with CT and MRI imaging often limited by metal artifacts. To describe the [F-18]2-fluoro-2-deoxyglucose (FDG) PET/CT appearance of local osteosarcoma recurrences with correlation to findings on other imaging modalities. A retrospective review of pediatric osteosarcoma patients imaged with FDG PET/CT was performed in patients with pathologically proven local recurrences. FDG PET/CT findings were reviewed and correlated with available comparison imaging studies. Ten local osteosarcoma recurrences in eight pediatric osteosarcoma patients were imaged with FDG PET/CT. All eight patients had a local recurrence after limb salvage; two patients had a second local recurrence after amputation. All local recurrences were seen with FDG PET/CT, demonstrating solid (n=5) or peripheral/nodular (n=5) FDG uptake patterns. Maximum standard uptake values (SUVs) ranged from 3.0 to 15.7. In five recurrences imaged with FDG PET/CT and MRI, MRI was limited or nondiagnostic in three. In four recurrences imaged with FDG PET/CT and bone scan, the bone scan was negative in three. Local osteosarcoma recurrences are well visualized by FDG PET/CT, demonstrating either solid or peripheral/nodular FDG uptake with a wide range of maximum SUVs. FDG PET/CT demonstrates the full extent of local recurrences, while MRI can be limited by artifact from metallic hardware. PET/CT appears to be more sensitive than bone scan in detecting local osteosarcoma recurrences. (orig.)

Pediatric chest CT after trauma: impact on surgical and clinical management

International Nuclear Information System (INIS)

Patel, Rina P.; Hernanz-Schulman, Marta; Hilmes, Melissa A.; Kan, J.H.; Yu, Chang; Ray, Jackie

2010-01-01

Chest CT after pediatric trauma is frequently performed but its clinical impact, particularly with respect to surgical intervention, has not been adequately evaluated. To assess the impact of chest CT compared with chest radiography on pediatric trauma management. Two hundred thirty-five consecutive pediatric trauma patients who had both chest CT and radiography were identified. Images were reviewed and findings were categorized and correlated with subsequent chest interventions, blinded to final outcome and management. Of the 235 children, 38.3% (90/235) had an abnormal chest radiograph and 63.8% (150/235) had an abnormal chest CT (P < 0.0001). Chest interventions followed in 4.7% (11/235); of these, the findings could be made 1 cm above the dome of the liver in 91% (10/11). Findings requiring chest intervention included pneumothorax (PTX) and vertebral fractures. PTX was found on 2.1% (5/235) of chest radiographs and 20.0% (47/235) of chest CTs (P < 0.0001); 1.7% (4/235) of the children received a chest tube for PTX, 0.85% (2/235) seen on chest CT only. Vertebral fractures were present in 3.8% of the children (9/235) and 66.7% (6/9) of those cases were treated with spinal fusion or brace. There were no instances of mediastinal vascular injury. Most intrathoracic findings requiring surgical management in our population were identified in the lower chest and would be included in routine abdominopelvic CT exams; this information needs to be taken into consideration in the diagnostic algorithm of pediatric trauma patients. (orig.)

Pediatric chest CT after trauma: impact on surgical and clinical management

Energy Technology Data Exchange (ETDEWEB)

Patel, Rina P. [Vanderbilt University School of Medicine, Nashville, TN (United States); Hernanz-Schulman, Marta; Hilmes, Melissa A.; Kan, J.H. [Vanderbilt University, Department of Radiology and Radiological Sciences, Vanderbilt Children' s Hospital, Nashville, TN (United States); Yu, Chang [Vanderbilt University, Department of Biostatistics, Nashville, TN (United States); Ray, Jackie [Vanderbilt University, Department of Pediatric Surgery, Vanderbilt Children' s Hospital, Nashville, TN (United States)

2010-07-15

Chest CT after pediatric trauma is frequently performed but its clinical impact, particularly with respect to surgical intervention, has not been adequately evaluated. To assess the impact of chest CT compared with chest radiography on pediatric trauma management. Two hundred thirty-five consecutive pediatric trauma patients who had both chest CT and radiography were identified. Images were reviewed and findings were categorized and correlated with subsequent chest interventions, blinded to final outcome and management. Of the 235 children, 38.3% (90/235) had an abnormal chest radiograph and 63.8% (150/235) had an abnormal chest CT (P < 0.0001). Chest interventions followed in 4.7% (11/235); of these, the findings could be made 1 cm above the dome of the liver in 91% (10/11). Findings requiring chest intervention included pneumothorax (PTX) and vertebral fractures. PTX was found on 2.1% (5/235) of chest radiographs and 20.0% (47/235) of chest CTs (P < 0.0001); 1.7% (4/235) of the children received a chest tube for PTX, 0.85% (2/235) seen on chest CT only. Vertebral fractures were present in 3.8% of the children (9/235) and 66.7% (6/9) of those cases were treated with spinal fusion or brace. There were no instances of mediastinal vascular injury. Most intrathoracic findings requiring surgical management in our population were identified in the lower chest and would be included in routine abdominopelvic CT exams; this information needs to be taken into consideration in the diagnostic algorithm of pediatric trauma patients. (orig.)

Patient-specific dose estimation for pediatric chest CT

Energy Technology Data Exchange (ETDEWEB)

Li Xiang; Samei, Ehsan; Segars, W. Paul; Sturgeon, Gregory M.; Colsher, James G.; Frush, Donald P. [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Physics, Duke University, Durham, North Carolina 27710 (United States); and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Global Applied Science Laboratory, GE Healthcare, Waukesha, Wisconsin 53188 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Department of Radiology, Division of Pediatric Radiology, Duke University Medical Center, Durham North Carolina 27710 (United States)

2008-12-15

dose for any other patient in the same size/protocol group who undergoes the chest scan. In summary, this work reported the first assessment of dose variations across pediatric CT patients in the same size/protocol group due to the variability of patient anatomy and body habitus and provided a previously unavailable method for patient-specific organ dose estimation, which will help in assessing patient risk and optimizing dose reduction strategies, including the development of scan protocols.

Comparative Study of the CT Findings and Clinical Features in Pediatric and Adult Sialadenitis

International Nuclear Information System (INIS)

Han, Jong Kyu; Jo, Seong Shik; Kim, Sang Won; Kim, Young Tong; Shin, Hyeong Cheol; Kim, Il Young; Lee, Yong Man

2010-01-01

We wanted to compare the CT findings and clinical features of parotitis and submandibular sialadenitis in children and adults and to evaluate the statistical significance of these in different age groups and the usefulness of a CT scan. Ninety-seven adults and 36 pediatric patients with sialadenitis were included in this retrospective study. Regardless of the site of involvement, we evaluated the CT findings and clinical manifestations between the pediatric and adult groups, and between the pediatric and adult parotitis and submandibular sialadenitis groups. At last, all the patients were classified into seven age groups. Abscess formations were more prominent in the parotitis groups, and sialiths were more common in the submandibular sialadenitis group with the lowest incidence in the young children group (≤ 10 years). Cellulitis seen on a CT scan showed a higher incidence in the adult parotitis group, and this finding was closely connected with pain. A number of patients showed cervical lymphadenitis on a CT scan and this coincided with lymph node palpation. Tonsillitis associated sialadenitis was common in the pediatric group. The therapeutic durations were longer in the pediatric parotitis patient group and the adult submandibular sialadenitis group. CT scans were very helpful to evaluate for abscess, stone, lymphadenitis and estimating the associated clinical manifestations such as swelling, palpable lymph nodes, pain with operation and the therapeutic plan

SU-E-I-68: Practical Considerations On Implementation of the Image Gently Pediatric CT Protocols

International Nuclear Information System (INIS)

Zhang, J; Adams, C; Lumby, C; Dillon, J; Woods, E; Richer, E

2014-01-01

Purpose: One limitation associated with the Image Gently pediatric CT protocols is practical implementation of the recommended manual techniques. Inconsistency as a result of different practice is a possibility among technologist. An additional concern is the added risk of data error that would result in over or underexposure. The Automatic Exposure Control (AEC) features automatically reduce radiation for children. However, they do not work efficiently for the patients of very small size and relative large size. This study aims to implement the Image Gently pediatric CT protocols in the practical setting while maintaining the use of AEC features for pediatric patients of varying size. Methods: Anthropomorphological abdomen phantoms were scanned in a CT scanner using the Image Gently pediatric protocols, the AEC technique with a fixed adult baseline, and automatic protocols with various baselines. The baselines were adjusted corresponding to patient age, weight and posterioranterior thickness to match the Image Gently pediatric CT manual techniques. CTDIvol was recorded for each examination. Image noise was measured and recorded for image quality comparison. Clinical images were evaluated by pediatric radiologists. Results: By adjusting vendor default baselines used in the automatic techniques, radiation dose and image quality can match those of the Image Gently manual techniques. In practice, this can be achieved by dividing pediatric patients into three major groups for technologist reference: infant, small child, and large child. Further division can be done but will increase the number of CT protocols. For each group, AEC can efficiently adjust acquisition techniques for children. This implementation significantly overcomes the limitation of the Image Gently manual techniques. Conclusion: Considering the effectiveness in clinical practice, Image Gently Pediatric CT protocols can be implemented in accordance with AEC techniques, with adjusted baselines, to

Radiation dose associated with CT-guided drain placement for pediatric patients

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Schwartz, Cody J.; Isaacson, Ari J.; Fordham, Lynn Ansley; Ivanovic, Marija; Dixon, Robert G. [University of North Carolina at Chapel Hill, Department of Radiology, UNC Health Care, Chapel Hill, NC (United States); Taylor, J.B. [University of North Carolina at Chapel Hill, Environment, Health and Safety, Chapel Hill, NC (United States)

2017-05-15

To date, there are limited radiation dose data on CT-guided procedures in pediatric patients. Our goal was to quantify the radiation dose associated with pediatric CT-guided drain placement and follow-up drain evaluations in order to estimate effective dose. We searched the electronic medical record and picture archiving and communication system (PACS) to identify all pediatric (<18 years old) CT-guided drain placements performed between January 2008 and December 2013 at our institution. We compiled patient data and radiation dose information from CT-guided drain placements as well as pre-procedural diagnostic CTs and post-procedural follow-up fluoroscopic abscess catheter injections (sinograms). Then we converted dose-length product, fluoroscopy time and number of acquisitions to effective doses using Monte Carlo simulations and age-appropriate conversion factors based on annual quality-control testing. Fifty-two drainages were identified with mean patient age of 11.0 years (5 weeks to 17 years). Most children had diagnoses of appendicitis (n=23) or inflammatory bowel disease (n=11). Forty-seven patients had diagnostic CTs, with a mean effective dose of 7.3 mSv (range 1.1-25.5 mSv). Drains remained in place for an average of 16.9 days (range 0-75 days), with an average of 0.9 (0-5) sinograms per patient in follow-up. The mean effective dose for all drainages and follow-up exams was 5.3 mSv (0.7-17.1) and 62% (32/52) of the children had effective doses less than 5 mSv. The majority of pediatric patients who have undergone CT-guided drain placements at our institution have received total radiation doses on par with diagnostic ranges. This information could be useful when describing the dose of radiation to parents and providers when CT-guided drain placement is necessary. (orig.)

Radiation dose associated with CT-guided drain placement for pediatric patients

International Nuclear Information System (INIS)

Schwartz, Cody J.; Isaacson, Ari J.; Fordham, Lynn Ansley; Ivanovic, Marija; Dixon, Robert G.; Taylor, J.B.

2017-01-01

To date, there are limited radiation dose data on CT-guided procedures in pediatric patients. Our goal was to quantify the radiation dose associated with pediatric CT-guided drain placement and follow-up drain evaluations in order to estimate effective dose. We searched the electronic medical record and picture archiving and communication system (PACS) to identify all pediatric (<18 years old) CT-guided drain placements performed between January 2008 and December 2013 at our institution. We compiled patient data and radiation dose information from CT-guided drain placements as well as pre-procedural diagnostic CTs and post-procedural follow-up fluoroscopic abscess catheter injections (sinograms). Then we converted dose-length product, fluoroscopy time and number of acquisitions to effective doses using Monte Carlo simulations and age-appropriate conversion factors based on annual quality-control testing. Fifty-two drainages were identified with mean patient age of 11.0 years (5 weeks to 17 years). Most children had diagnoses of appendicitis (n=23) or inflammatory bowel disease (n=11). Forty-seven patients had diagnostic CTs, with a mean effective dose of 7.3 mSv (range 1.1-25.5 mSv). Drains remained in place for an average of 16.9 days (range 0-75 days), with an average of 0.9 (0-5) sinograms per patient in follow-up. The mean effective dose for all drainages and follow-up exams was 5.3 mSv (0.7-17.1) and 62% (32/52) of the children had effective doses less than 5 mSv. The majority of pediatric patients who have undergone CT-guided drain placements at our institution have received total radiation doses on par with diagnostic ranges. This information could be useful when describing the dose of radiation to parents and providers when CT-guided drain placement is necessary. (orig.)

TH-B-207B-02: Optimizing Pediatic Cardiovascular MRI

International Nuclear Information System (INIS)

Deng, J.

2016-01-01

This imaging educational program will focus on solutions to common pediatric image quality optimization challenges. The speakers will present collective knowledge on best practices in pediatric imaging from their experience at dedicated children’s hospitals. One of the most commonly encountered pediatric imaging requirements for the non-specialist hospital is pediatric CT in the emergency room setting. Thus, this educational program will begin with optimization of pediatric CT in the emergency department. Though pediatric cardiovascular MRI may be less common in the non-specialist hospitals, low pediatric volumes and unique cardiovascular anatomy make optimization of these techniques difficult. Therefore, our second speaker will review best practices in pediatric cardiovascular MRI based on experiences from a children’s hospital with a large volume of cardiac patients. Learning Objectives: To learn techniques for optimizing radiation dose and image quality for CT of children in the emergency room setting. To learn solutions for consistently high quality cardiovascular MRI of children

TH-B-207B-02: Optimizing Pediatic Cardiovascular MRI

Energy Technology Data Exchange (ETDEWEB)

Deng, J. [Ann & Robert H. Lurie Childrens Hospital, Chicago, IL (United States)

2016-06-15

This imaging educational program will focus on solutions to common pediatric image quality optimization challenges. The speakers will present collective knowledge on best practices in pediatric imaging from their experience at dedicated children’s hospitals. One of the most commonly encountered pediatric imaging requirements for the non-specialist hospital is pediatric CT in the emergency room setting. Thus, this educational program will begin with optimization of pediatric CT in the emergency department. Though pediatric cardiovascular MRI may be less common in the non-specialist hospitals, low pediatric volumes and unique cardiovascular anatomy make optimization of these techniques difficult. Therefore, our second speaker will review best practices in pediatric cardiovascular MRI based on experiences from a children’s hospital with a large volume of cardiac patients. Learning Objectives: To learn techniques for optimizing radiation dose and image quality for CT of children in the emergency room setting. To learn solutions for consistently high quality cardiovascular MRI of children.

Chest CT findings in pediatric Wegener's granulomatosis

Energy Technology Data Exchange (ETDEWEB)

Levine, Daniel [British Columbia Children' s Hospital, Department of Radiology and Nuclear Medicine, Vancouver, British Columbia (Canada); Akikusa, Jonathan [Royal Children' s Hospital Melbourne, Department of Rheumatology, Melbourne (Australia); Manson, David [Hospital for Sick Children, Department of Radiology, Toronto (Canada); Silverman, Earl; Schneider, Rayfel [Hospital for Sick Children, Department of Rheumatology, Toronto (Canada)

2007-01-15

Although pulmonary involvement occurs in the majority of children and adolescents with Wegener's granulomatosis (WG), relatively little has been published regarding the CT imaging manifestations in this group of patients. To determine the frequency and types of chest CT abnormalities in active pediatric WG (pWG). The study was a retrospective examination of 29 chest CT examinations performed at diagnosis (n=14) and during disease flares (n=15) in 18 children. The most common abnormalities were nodules (seen in 90% of examinations), ground-glass opacification (52%), and air-space opacification (45%). Of examinations with nodules, 73% demonstrated nodules >5 mm in diameter and 69% demonstrated more than five nodules; 17% had cavitary lesions. The only abnormality with a significant difference in prevalence between diagnosis and disease flares was air-space opacification, present in 71% and 20%, respectively (P < 0.01). In accordance with the findings of published adult studies and at variance with those of prior pediatric studies, our findings indicate that chest CT abnormalities in active pWG are frequent, most commonly comprising nodules and ground-glass opacification, which may be difficult to detect on plain radiography. We therefore advocate the routine use of chest CT for all affected patients, both at the time of presentation and during disease flares. (orig.)

Value of postmortem thoracic CT over radiography in imaging of pediatric rib fractures

Energy Technology Data Exchange (ETDEWEB)

Hong, Terence S.; Babyn, Paul S. [The Hospital for Sick Children, Department of Diagnostic Imaging, Toronto (Canada); Reyes, Jeanette A.; Chiasson, David A. [The Hospital for Sick Children, Department of Paediatric Laboratory Medicine, Toronto (Canada); Moineddin, Rahim [University of Toronto, Department of Family and Community Medicine, Toronto (Canada); Berdon, Walter E. [Columbia Presbyterian Medical Center, Babies Hospital, Department of Radiology, New York, NY (United States)

2011-06-15

Studies have reported that thoracic CT may provide greater sensitivity compared with radiography in detection of pediatric rib fractures and fracture healing. The additional sensitivity afforded by thoracic CT may have medicolegal implications where abuse is suspected. To determine the additional value of postmortem thoracic CT compared with radiography in detecting pediatric rib fractures, and fracture healing, using autopsy findings as a gold standard. We retrospectively reviewed 56 coroner's cases with postmortem radiography and CT thoracic survey. All studies underwent primary interpretation by one or two radiologists. The study radiologist independently reviewed all images from 13 patients with positive findings on radiography, CT or autopsy. Sensitivity and specificity between observers and imaging modalities were compared. Primary interpretation: Fractures were recognized on radiography in 5/12 patients who had fractures found at autopsy, and on CT in 8/12 patients. In total, 29% (24/83) of fractures were reported on radiography, and 51% (52/101) of fractures were reported on CT. Study radiologist: Fractures were recognized on radiography in 7/12 patients who had fractures found at autopsy, and on CT in 11/12 patients. In total, 46% (38/83) of fractures were reported on radiography, and 85% (86/101) of fractures were reported on CT. Postmortem thoracic CT provides greater sensitivity than radiography in detecting pediatric rib fractures, most notably in anterior and posterior fractures. However, the degree of improvement in sensitivity provided by CT might depend on observer experience. (orig.)

Pediatric personalized CT-dosimetry Monte Carlo simulations, using computational phantoms

International Nuclear Information System (INIS)

Papadimitroulas, P; Kagadis, G C; Ploussi, A; Kordolaimi, S; Papamichail, D; Karavasilis, E; Syrgiamiotis, V; Loudos, G

2015-01-01

The last 40 years Monte Carlo (MC) simulations serve as a “gold standard” tool for a wide range of applications in the field of medical physics and tend to be essential in daily clinical practice. Regarding diagnostic imaging applications, such as computed tomography (CT), the assessment of deposited energy is of high interest, so as to better analyze the risks and the benefits of the procedure. The last few years a big effort is done towards personalized dosimetry, especially in pediatric applications. In the present study the GATE toolkit was used and computational pediatric phantoms have been modeled for the assessment of CT examinations dosimetry. The pediatric models used come from the XCAT and IT'IS series. The X-ray spectrum of a Brightspeed CT scanner was simulated and validated with experimental data. Specifically, a DCT-10 ionization chamber was irradiated twice using 120 kVp with 100 mAs and 200 mAs, for 1 sec in 1 central axial slice (thickness = 10mm). The absorbed dose was measured in air resulting in differences lower than 4% between the experimental and simulated data. The simulations were acquired using ∼10 10 number of primaries in order to achieve low statistical uncertainties. Dose maps were also saved for quantification of the absorbed dose in several children critical organs during CT acquisition. (paper)

Trends in CT Request and Related Outcomes in a Pediatric Emergency Department

Directory of Open Access Journals (Sweden)

S.M. Saiful Islam

2016-09-01

Full Text Available Objectives: To study and to establish the overall trends of computed tomography (CT use and associated outcomes in the pediatric emergency department (PED at Royal Hospital, Oman, from 2010 to 2014. Methods: The hospital electronic medical record was retrospectively searched to find children (from birth to 12 years old who had visited the PED and the number of CT requests between 1 January 2010 and 31 December 2014. The types of CT examinations ordered were analyzed according to anatomical location and were as follows; head, abdomen/pelvis, chest, cervical spine/neck, and others. Results: There were a total of 67 244 PED visits during the study period, 569 of which received 642 CT scans. There was a remarkable rise in CT uses per 1000 visits from 7 in 2010 to 12 in 2014. There was a 56% hike in CT requests from 87 in 2010 to 175 in 2014 while the number of pediatric emergency visits rose by about 28% from 11 721 to 15 052. Although head CT scans were the most common, cervical spine CT scans had the highest rate of increase (600% followed by the chest (112%, head (54% and abdomen (13%. There were no significant changes in other CT scan requests. The cost of CT scans increased from $18 096 to $36 400 during the study period, which increased the average PED cost by about $2 per visit. The average time between a CT being requested and then performed was 1.24 hours. Conclusions: CT use in the pediatric emergency department has risen significantly at a rate that markedly exceeds the growth of emergency visits. This is associated with an increase in PED costs and longer waiting times.

Iterative reconstruction technique with reduced volume CT dose index: diagnostic accuracy in pediatric acute appendicitis

International Nuclear Information System (INIS)

Didier, Ryne A.; Vajtai, Petra L.; Hopkins, Katharine L.

2015-01-01

Iterative reconstruction technique has been proposed as a means of reducing patient radiation dose in pediatric CT. Yet, the effect of such reductions on diagnostic accuracy has not been thoroughly evaluated. This study compares accuracy of diagnosing pediatric acute appendicitis using contrast-enhanced abdominopelvic CT scans performed with traditional pediatric weight-based protocols and filtered back projection reconstruction vs. a filtered back projection/iterative reconstruction technique blend with reduced volume CT dose index (CTDI vol ). Results of pediatric contrast-enhanced abdominopelvic CT scans done for pain and/or suspected appendicitis were reviewed in two groups: A, 192 scans performed with the hospital's established weight-based CT protocols and filtered back projection reconstruction; B, 194 scans performed with iterative reconstruction technique and reduced CTDI vol . Reduced CTDI vol was achieved primarily by reductions in effective tube current-time product (mAs eff ) and tube peak kilovoltage (kVp). CT interpretation was correlated with clinical follow-up and/or surgical pathology. CTDI vol , size-specific dose estimates (SSDE) and performance characteristics of the two CT techniques were then compared. Between groups A and B, mean CTDI vol was reduced by 45%, and mean SSDE was reduced by 46%. Sensitivity, specificity and diagnostic accuracy were 96%, 97% and 96% in group A vs. 100%, 99% and 99% in group B. Accuracy in diagnosing pediatric acute appendicitis was maintained in contrast-enhanced abdominopelvic CT scans that incorporated iterative reconstruction technique, despite reductions in mean CTDI vol and SSDE by nearly half as compared to the hospital's traditional weight-based protocols. (orig.)

Preliminary experience on the use of PET/CT in the management of pediatric post-transplant lymphoproliferative disorder.

Science.gov (United States)

Guerra-García, Pilar; Hirsch, Steffen; Levine, Daniel S; Taj, Mary M

2017-12-01

Post-transplant lymphoproliferative disorder (PTLD) is a well-known complication following prolonged immunosuppression. Contrary to other lymphomas, there is no standardized imaging approach to assess PTLD either at staging or for response to therapy. Positron emission tomography/computed tomography (PET/CT) is an imaging modality that has proven to be useful in lymphoma. However, there is still limited data concerning its use in pediatric PTLD. Our study evaluates the use of PET/CT in pediatric PTLD at our institution. To assess the role of PET/CT in pediatric PTLD, we reviewed the pediatric patients with PTLD who had undergone PET/CT at our institution between 2000 and 2016. Nine patients were identified. Six had PET/CT at diagnosis. All lesions seen on CT were identified with PET/CT. Fourteen PET/CTs were done during treatment. Eight PET/CTs were negative, including three where CT showed areas of uncertain significance. In these cases, PET/CT helped us to stop treatment and the patients remain in remission after a long follow-up (mean 74.3 months; range 12.4-180.9 months). PET/CT revealed additional disease in two cases, therefore treatment was intensified. Six biopsies and close follow-up was done to confirm PET/CT results. In one case, PET/CT did not identify central nervous system involvement demonstrated on magnetic resonance imaging. PET/CT may have an important role in the staging and follow-up of pediatric PTLD. In our cohort, PET/CT was helpful in staging and assessing treatment response and in clarifying equivocal findings on other imaging modalities. © 2017 Wiley Periodicals, Inc.

Iterative reconstruction technique with reduced volume CT dose index: diagnostic accuracy in pediatric acute appendicitis

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Didier, Ryne A. [Oregon Health and Science University, Department of Diagnostic Radiology, DC7R, Portland, OR (United States); Vajtai, Petra L. [Oregon Health and Science University, Department of Pediatrics, Portland, OR (United States); Oregon Health and Science University, Department of Diagnostic Radiology, DC7R, Portland, OR (United States); Hopkins, Katharine L. [Oregon Health and Science University, Department of Diagnostic Radiology, DC7R, Portland, OR (United States); Oregon Health and Science University, Department of Pediatrics, Portland, OR (United States)

2014-07-05

Iterative reconstruction technique has been proposed as a means of reducing patient radiation dose in pediatric CT. Yet, the effect of such reductions on diagnostic accuracy has not been thoroughly evaluated. This study compares accuracy of diagnosing pediatric acute appendicitis using contrast-enhanced abdominopelvic CT scans performed with traditional pediatric weight-based protocols and filtered back projection reconstruction vs. a filtered back projection/iterative reconstruction technique blend with reduced volume CT dose index (CTDI{sub vol}). Results of pediatric contrast-enhanced abdominopelvic CT scans done for pain and/or suspected appendicitis were reviewed in two groups: A, 192 scans performed with the hospital's established weight-based CT protocols and filtered back projection reconstruction; B, 194 scans performed with iterative reconstruction technique and reduced CTDI{sub vol}. Reduced CTDI{sub vol} was achieved primarily by reductions in effective tube current-time product (mAs{sub eff}) and tube peak kilovoltage (kVp). CT interpretation was correlated with clinical follow-up and/or surgical pathology. CTDI{sub vol}, size-specific dose estimates (SSDE) and performance characteristics of the two CT techniques were then compared. Between groups A and B, mean CTDI{sub vol} was reduced by 45%, and mean SSDE was reduced by 46%. Sensitivity, specificity and diagnostic accuracy were 96%, 97% and 96% in group A vs. 100%, 99% and 99% in group B. Accuracy in diagnosing pediatric acute appendicitis was maintained in contrast-enhanced abdominopelvic CT scans that incorporated iterative reconstruction technique, despite reductions in mean CTDI{sub vol} and SSDE by nearly half as compared to the hospital's traditional weight-based protocols. (orig.)

PET/CT for staging and follow-up of pediatric nasopharyngeal carcinoma

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Cheuk, Daniel K.L. [St Jude Children' s Research Hospital, Department of Oncology, Memphis, TN (United States); The University of Hong Kong, Department of Paediatrics and Adolescent Medicine, Pokfulam (China); Sabin, Noah D.; Hossain, Moinul; Krasin, Matthew J.; Shulkin, Barry L. [St Jude Children' s Research Hospital, Department of Radiological Sciences, Memphis, TN (United States); Wozniak, Amy [St Jude Children' s Research Hospital, Department of Biostatistics, Memphis, TN (United States); Naik, Mihir [St Jude Children' s Research Hospital, Department of Radiological Sciences, Memphis, TN (United States); University of Texas Health Science Center, Department of Radiation Oncology, San Antonio, TX (United States); Rodriguez-Galindo, Carlos [St Jude Children' s Research Hospital, Department of Oncology, Memphis, TN (United States); Hematology/Oncology, Dana-Farber Cancer Institute, Boston, MA (United States)

2012-07-15

While FDG PET/CT for the evaluation of nasopharyngeal carcinoma (NPC) in adult patients has documented advantages and disadvantages compared with conventional imaging, to our knowledge, no studies of FDG PET/CT for the evaluation of NPC in pediatric patients have been performed. In this investigation, we studied the utility of FDG PET/CT in children with NPC. The study group comprised 18 children with biopsy-proven NPC who underwent FDG PET/CT and MRI (total 38 pairs of images). All baseline and follow-up FDG PET/CT and MRI studies were independently reviewed for restaging of disease. The concordance between FDG PET/CT and MRI in T, N, and overall staging was 29%, 64%, and 43%, respectively. Compared with MRI, FDG PET/CT yielded lower T and overall staging and showed less cervical and retropharyngeal lymphadenopathy. The concordance between follow-up FDG PET/CT and MRI was 79% overall and 100% 9 months after therapy. In patients who achieved complete remission, FDG PET/CT showed disease clearance 3-6 months earlier than MRI. There were no false-positive or false-negative FDG PET/CT scans during follow-up. FDG PET/CT may underestimate tumor extent and regional lymphadenopathy compared with MRI at the time of diagnosis, but it helps to detect metastases and clarify ambiguous findings. FDG PET/CT is sensitive and specific for follow-up and enables earlier determination of disease remission. FDG PET/CT is a valuable imaging modality for the evaluation and monitoring of NPC in pediatric patients. (orig.)

Radiation risk index for pediatric CT. A patient-derived metric

International Nuclear Information System (INIS)

Samei, Ehsan; Tian, Xiaoyu; Paul Segars, W.; Frush, Donald P.

2017-01-01

There is a benefit in characterizing radiation-induced cancer risk in pediatric chest and abdominopelvic CT: a singular metric that represents the whole-body radiation burden while also accounting for age, gender and organ sensitivity. To compute an index of radiation risk for pediatric chest and abdominopelvic CT. Using a protocol approved by our institutional review board, 42 pediatric patients (age: 0-16 years, weight: 2-80 kg) were modeled into virtual whole-body anatomical models. Organ doses were estimated for clinical chest and abdominopelvic CT examinations of the patients using validated Monte Carlo simulations of two major scanner models. Using age-, size- and gender-specific organ risk coefficients, the values were converted to normalized effective dose (by dose length product) (denoted as the k factor) and a normalized risk index (denoted as the q factor). An analysis was performed to determine how these factors are correlated with patient age and size for both males and females to provide a strategy to better characterize individualized risk. The k factor was found to be exponentially correlated with the average patient diameter. For both genders, the q factor also exhibited an exponential relationship with both the average patient diameter and with patient age. For both factors, the differences between the scanner models were less than 8%. The study defines a whole-body radiation risk index for chest and abdominopelvic CT imaging, that incorporates individual estimated organ dose values, organ radiation sensitivity, patient size, exposure age and patient gender. This indexing metrology enables the assessment and potential improvement of chest and abdominopelvic CT performance through surveillance of practice dose profiles across patients and may afford improved informed communication. (orig.)

Radiation risk index for pediatric CT. A patient-derived metric

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Samei, Ehsan [Duke University Medical Center, Department of Radiology, Carl E. Ravin Advanced Imaging Laboratories, Durham, NC (United States); Duke University Medical Center, Department of Biomedical Engineering, Electrical and Computer Engineering, Durham, NC (United States); Duke University Medical Center, Medical Physics Graduate Program, Durham, NC (United States); Tian, Xiaoyu [Duke University Medical Center, Department of Radiology, Carl E. Ravin Advanced Imaging Laboratories, Durham, NC (United States); Paul Segars, W. [Duke University Medical Center, Department of Radiology, Carl E. Ravin Advanced Imaging Laboratories, Durham, NC (United States); Duke University Medical Center, Medical Physics Graduate Program, Durham, NC (United States); Frush, Donald P. [Duke University Medical Center, Medical Physics Graduate Program, Durham, NC (United States); Duke University Medical Center, Division of Pediatric Radiology, Department of Radiology, Durham, NC (United States)

2017-12-15

There is a benefit in characterizing radiation-induced cancer risk in pediatric chest and abdominopelvic CT: a singular metric that represents the whole-body radiation burden while also accounting for age, gender and organ sensitivity. To compute an index of radiation risk for pediatric chest and abdominopelvic CT. Using a protocol approved by our institutional review board, 42 pediatric patients (age: 0-16 years, weight: 2-80 kg) were modeled into virtual whole-body anatomical models. Organ doses were estimated for clinical chest and abdominopelvic CT examinations of the patients using validated Monte Carlo simulations of two major scanner models. Using age-, size- and gender-specific organ risk coefficients, the values were converted to normalized effective dose (by dose length product) (denoted as the k factor) and a normalized risk index (denoted as the q factor). An analysis was performed to determine how these factors are correlated with patient age and size for both males and females to provide a strategy to better characterize individualized risk. The k factor was found to be exponentially correlated with the average patient diameter. For both genders, the q factor also exhibited an exponential relationship with both the average patient diameter and with patient age. For both factors, the differences between the scanner models were less than 8%. The study defines a whole-body radiation risk index for chest and abdominopelvic CT imaging, that incorporates individual estimated organ dose values, organ radiation sensitivity, patient size, exposure age and patient gender. This indexing metrology enables the assessment and potential improvement of chest and abdominopelvic CT performance through surveillance of practice dose profiles across patients and may afford improved informed communication. (orig.)

Low-tube-voltage selection for non-contrast-enhanced CT: Comparison of the radiation dose in pediatric and adult phantoms.

Science.gov (United States)

Shimonobo, Toshiaki; Funama, Yoshinori; Utsunomiya, Daisuke; Nakaura, Takeshi; Oda, Seitaro; Kiguchi, Masao; Masuda, Takanori; Sakabe, Daisuke; Yamashita, Yasuyuki; Awai, Kazuo

2016-01-01

We used pediatric and adult anthropomorphic phantoms to compare the radiation dose of low- and standard tube voltage chest and abdominal non-contrast-enhanced computed tomography (CT) scans. We also discuss the optimal low tube voltage for non-contrast-enhanced CT. Using a female adult- and three differently-sized pediatric anthropomorphic phantoms we acquired chest and abdominal non-contrast-enhanced scans on a 320-multidetector CT volume scanner. The tube voltage was set at 80-, 100-, and 120 kVp. The tube current was automatically assigned on the CT scanner in response to the set image noise level. On each phantom and at each tube voltage we measured the surface and center dose using high-sensitivity metal-oxide-semiconductor field-effect transistor detectors. The mean surface dose of chest and abdominal CT scans in 5-year olds was 4.4 and 5.3 mGy at 80 kVp, 4.5 and 5.4 mGy at 100 kV, and 4.0 and 5.0 mGy at 120 kVp, respectively. These values were similar in our 3-pediatric phantoms (p > 0.05). The mean surface dose in the adult phantom increased from 14.7 to 19.4 mGy for chest- and from 18.7 to 24.8 mGy for abdominal CT as the tube voltage decreased from 120 to 80 kVp (p voltage and the low tube voltage technique can be used for non-contrast-enhanced chest- and abdominal scanning. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Practical techniques for pediatric computed tomography

International Nuclear Information System (INIS)

Fitz, C.R.; Harwood-Nash, D.C.; Kirks, D.R.; Kaufman, R.A.; Berger, P.E.; Kuhn, J.P.; Siegel, M.J.

1983-01-01

Dr. Donald Kirks has assembled this section on Practical Techniques for Pediatric Computed Tomography. The material is based on a presentation in the Special Interest session at the 25th Annual Meeting of the Society for Pediatric Radiology in New Orleans, Louisiana, USA in 1982. Meticulous attention to detail and technique is required to ensure an optimal CT examination. CT techniques specifically applicable to infants and children have not been disseminated in the radiology literature and in this respect it may rightly be observed that ''the child is not a small adult''. What follows is a ''cookbook'' prepared by seven participants and it is printed in Pediatric Radiology, in outline form, as a statement of individual preferences for pediatric CT techniques. This outline gives concise explanation of techniques and permits prompt dissemination of information. (orig.)

The use of adaptive statistical iterative reconstruction in pediatric head CT: a feasibility study.

Science.gov (United States)

Vorona, G A; Zuccoli, G; Sutcavage, T; Clayton, B L; Ceschin, R C; Panigrahy, A

2013-01-01

Iterative reconstruction techniques facilitate CT dose reduction; though to our knowledge, no group has explored using iterative reconstruction with pediatric head CT. Our purpose was to perform a feasibility study to assess the use of ASIR in a small group of pediatric patients undergoing head CT. An Alderson-Rando head phantom was scanned at decreasing 10% mA intervals relative to our standard protocol, and each study was then reconstructed at 10% ASIR intervals. An intracranial region of interest was consistently placed to estimate noise. Our ventriculoperitoneal shunt CT protocol was subsequently modified, and patients were scanned at 20% ASIR with approximately 20% mA reductions. ASIR studies were anonymously compared with older non-ASIR studies from the same patients by 2 attending pediatric neuroradiologists for diagnostic utility, sharpness, noise, and artifacts. The phantom study demonstrated similar noise at 100% mA/0% ASIR (3.9) and 80% mA/20% ASIR (3.7). Twelve pediatric patients were scanned at reduced dose at 20% ASIR. The average CTDI(vol) and DLP values of the 20% ASIR studies were 22.4 mGy and 338.4 mGy-cm, and for the non-ASIR studies, they were 28.8 mGy and 444.5 mGy-cm, representing statistically significant decreases in the CTDI(vol) (22.1%, P = .00007) and DLP (23.9%, P = .0005) values. There were no significant differences between the ASIR studies and non-ASIR studies with respect to diagnostic acceptability, sharpness, noise, or artifacts. Our findings suggest that 20% ASIR can provide approximately 22% dose reduction in pediatric head CT without affecting image quality.

Evaluation of X ray radiation doses in pediatric examinations of cranial computerized tomography based on optimization studies

International Nuclear Information System (INIS)

Daros, Kellen Adriana Curci

2005-01-01

This paper identifies the technical conditions for CT examination which offers lowest absorbed dose and to attend the manufacturer recommendations as far the spatial resolution is concerned. The paper evaluates the absorbed dose during cranial CT in up to 6 years children satisfying the technical condition recommended by the manufacturer and routine clinical conditions. The paper also established a quantitative relationship among the absorbed dose and its distribution in the cranial regions of pediatric patients up to 6 years old in a way to estimate the doses subject to optimized conditions

Development of a method to estimate organ doses for pediatric CT examinations

Energy Technology Data Exchange (ETDEWEB)

Papadakis, Antonios E., E-mail: apapadak@pagni.gr; Perisinakis, Kostas; Damilakis, John [Department of Medical Physics, University Hospital of Heraklion, Faculty of Medicine, University of Crete, P.O. Box 1352, Iraklion, Crete 71110 (Greece)

2016-05-15

Purpose: To develop a method for estimating doses to primarily exposed organs in pediatric CT by taking into account patient size and automatic tube current modulation (ATCM). Methods: A Monte Carlo CT dosimetry software package, which creates patient-specific voxelized phantoms, accurately simulates CT exposures, and generates dose images depicting the energy imparted on the exposed volume, was used. Routine head, thorax, and abdomen/pelvis CT examinations in 92 pediatric patients, ranging from 1-month to 14-yr-old (49 boys and 43 girls), were simulated on a 64-slice CT scanner. Two sets of simulations were performed in each patient using (i) a fixed tube current (FTC) value over the entire examination length and (ii) the ATCM profile extracted from the DICOM header of the reconstructed images. Normalized to CTDI{sub vol} organ dose was derived for all primary irradiated radiosensitive organs. Normalized dose data were correlated to patient’s water equivalent diameter using log-transformed linear regression analysis. Results: The maximum percent difference in normalized organ dose between FTC and ATCM acquisitions was 10% for eyes in head, 26% for thymus in thorax, and 76% for kidneys in abdomen/pelvis. In most of the organs, the correlation between dose and water equivalent diameter was significantly improved in ATCM compared to FTC acquisitions (P < 0.001). Conclusions: The proposed method employs size specific CTDI{sub vol}-normalized organ dose coefficients for ATCM-activated and FTC acquisitions in pediatric CT. These coefficients are substantially different between ATCM and FTC modes of operation and enable a more accurate assessment of patient-specific organ dose in the clinical setting.

Adaptive statistical iterative reconstruction: reducing dose while preserving image quality in the pediatric head CT examination

International Nuclear Information System (INIS)

McKnight, Colin D.; Watcharotone, Kuanwong; Ibrahim, Mohannad; Christodoulou, Emmanuel; Baer, Aaron H.; Parmar, Hemant A.

2014-01-01

Over the last decade there has been escalating concern regarding the increasing radiation exposure stemming from CT exams, particularly in children. Adaptive statistical iterative reconstruction (ASIR) is a relatively new and promising tool to reduce radiation dose while preserving image quality. While encouraging results have been found in adult head and chest and body imaging, validation of this technique in pediatric population is limited. The objective of our study was to retrospectively compare the image quality and radiation dose of pediatric head CT examinations obtained with ASIR compared to pediatric head CT examinations without ASIR in a large patient population. Retrospective analysis was performed on 82 pediatric head CT examinations. This group included 33 pediatric head CT examinations obtained with ASIR and 49 pediatric head CT examinations without ASIR. Computed tomography dose index (CTDI vol ) was recorded on all examinations. Quantitative analysis consisted of standardized measurement of attenuation and the standard deviation at the bilateral centrum semiovale and cerebellar white matter to evaluate objective noise. Qualitative analysis consisted of independent assessment by two radiologists in a blinded manner of gray-white differentiation, sharpness and overall diagnostic quality. The average CTDI vol value of the ASIR group was 21.8 mGy (SD = 4.0) while the average CTDI vol for the non-ASIR group was 29.7 mGy (SD = 13.8), reflecting a statistically significant reduction in CTDI vol in the ASIR group (P 12-year-old ASIR group as compared to the >12-year-old non-ASIR group (29.7 mGy vs. 49.9 mGy; P = 0.0002). Quantitative analysis revealed no significant difference in the homogeneity of variance in the ASIR group compared to the non-ASIR group. Radiologist assessment of gray-white differentiation, sharpness and overall diagnostic quality in ASIR examinations was not substantially different compared to non-ASIR examinations. The use of ASIR in

Improved spatial resolution and lower-dose pediatric CT imaging: a feasibility study to evaluate narrowing the X-ray photon energy spectrum

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Benz, Mark G. [Safer Pediatric Imaging and Engineering Horizons International, Lincoln, VT (United States); Benz, Matthew W. [Southboro Medical Group, Southboro, MA (United States); Birnbaum, Steven B. [Dartmouth Hitchcock Clinic Manchester, Department of Radiology, Manchester, NH (United States); Chason, Eric; Sheldon, Brian W. [Brown University, Division of Engineering, Materials Science and Engineering Program, Providence, RI (United States); McGuire, Dale [R and D Manager, C and G Technologies Inc., Jeffersonville, IN (United States)

2014-08-15

This feasibility study has shown that improved spatial resolution and reduced radiation dose can be achieved in pediatric CT by narrowing the X-ray photon energy spectrum. This is done by placing a hafnium filter between the X-ray generator and a pediatric abdominal phantom. A CT system manufactured in 1999 that was in the process of being remanufactured was used as the platform for this study. This system had the advantage of easy access to the X-ray generator for modifications to change the X-ray photon energy spectrum; it also had the disadvantage of not employing the latest post-imaging noise reduction iterative reconstruction technology. Because we observed improvements after changing the X-ray photon energy spectrum, we recommend a future study combining this change with an optimized iterative reconstruction noise reduction technique. (orig.)

Accuracy of CT-guided percutaneous core needle biopsy for assessment of pediatric musculoskeletal lesions

International Nuclear Information System (INIS)

Hryhorczuk, Anastasia L.; Strouse, Peter J.; Biermann, J.S.

2011-01-01

CT-guided percutaneous core needle biopsy has been shown in adults to be an effective diagnostic tool for a large number of musculoskeletal malignancies. To characterize our experience with CT-guided percutaneous core needle biopsy of pediatric bone lesions and determine its utility in diagnosing pediatric osseous lesions, in a population where such lesions are commonly benign. From 2000 to 2009, 61 children underwent 63 CT-guided percutaneous biopsies. Radiological, pathological and clinical records were reviewed. Fourteen biopsies (22%) were performed on malignant lesions, while 49 biopsies (78%) were performed on benign lesions. Forty-nine of the 63 biopsies (78%) were adequate; these children underwent no further tissue sampling. Fourteen of the 63 biopsies (22%) were inadequate or non-conclusive. Of these patients, 12 underwent open biopsy. Retrospective analysis of percutaneous biopsies in these patients demonstrates that 9/12 provided clinically relevant information, and 4/12 patients received final diagnoses that confirmed initial core biopsy findings. No malignancies were diagnosed as benign on percutaneous biopsy. Overall, percutaneous core needle biopsy provided accurate diagnostic information in 84% (53/63) of biopsies. Our results demonstrate that CT-guided percutaneous biopsy is safe and beneficial in children. This study supports the use of CT-guided percutaneous core needle biopsy for primary diagnosis of pediatric bone lesions. (orig.)

The role of 18F-FDG PET/CT in pediatric lymph-node acute lymphoblastic leukemia involvement.

Science.gov (United States)

Cistaro, Angelina; Saglio, Francesco; Asaftei, Sebastian; Fania, Piercarlo; Berger, Massimo; Fagioli, Franca

2011-01-01

In pediatric oncology, positron emission tomography/computed tomography (PET/CT) is emerging as an essential diagnostic tool in characterizing suspicious neoplastic lesions and staging malignant diseases. Most studies regarding the possible role of FDG-PET/CT in the management of acute lymphoblastic leukemia (ALL) patients are limited to adults. Here we report a pediatric patient with recurrent ALL, in which FDG-PET/CT was used both to define more precisely the cause of lymphadenopathy and to assess the effect of the second-line therapy.

Comparison of intracranial computed tomographic (CT) findings in pediatric abusive and accidental head trauma

International Nuclear Information System (INIS)

Hymel, K.P.; Rumack, C.M.; Hay, T.C.; Strain, J.D.; Jenny, C.

1997-01-01

Background. Child abuse specialists rely heavily on diagnostic neuroimaging. Objectives. Study objectives were: (1) to compare the frequencies of six specific intracranial CT abnormalities in accidental and non-accidental pediatric head trauma, and (2) to assess interobserver agreement regarding these CT findings. Materials and methods. Three pediatric radiologists blindly and independently reviewed cranial CT scans of pediatric patients who sustained closed head trauma between 1991 and 1994. All patients were less than 4 years of age. Study cases included thirty-nine (50 %) with non-accidental head trauma and thirty-nine (50 %) with accidental head trauma. Each scan was evaluated for the presence or absence of the following six intracranial findings: (1) interhemispheric falx hemorrhage, (2) subdural hemorrhage, (3) large (non-acute) extra-axial fluid, (4) basal ganglia edema, (5) posterior fossa hemorrhage, and (6) frontal-parietal shearing tear(s). Interobserver agreement was calculated as the percentage of total cases in which all reviewers agreed a specific CT finding was present or absent. Diagnosis required independent agreement by all three pediatric radiologists. The frequencies of these six intracranial CT abnormalities were compared between the two study groups by Chi-square analysis and Fisher's exact test. Results. Interobserver agreement between radiologists was greater than 80 % for all lesions evaluated, with the exception of frontal-parietal shearing tear(s). Interhemispheric falx hemorrhage, subdural hemorrhage, large (non-acute) extra-axial fluid, and basal ganglia edema were discovered significantly more frequently in non-accidental trauma (P ≤.05). Conclusion. Although not specific for child abuse, discovery of these intracranial CT abnormalities in young patients should prompt careful evaluation of family and injury circumstances for indicators of non-accidental trauma. (orig.). With 6 figs., 2 tabs

Thermoluminescent dosimetry of critical organs in CT pediatric patients

International Nuclear Information System (INIS)

Azorin, Juan; Tabares, Musel

2008-01-01

This paper presents the determination of absorbed dose in critical organs of pediatric patients submitted to head computed tomography (CT) studies. This research included patients up to 16 years old submitted to head CT studies using a Siemens Somaton 16 plus multislice CT scanner. Doses were measured using locally made LiF: Mg,Cu,P + PTFE thermoluminescent dosimeters (TLD) due to its tissue equivalence and low fading. Results showed that both the organ absorbed doses and the volume computed tomography dose index (CTDI vol ) determined for simple studies were half of those obtained for contrasted studies. In the case of head three-dimensional reconstruction CT studies the CTDI vol value obtained was almost the same that the obtained for simple CT studies but the organ doses were significantly different. These results suggest that the CTDI vol value is a good indication for choosing the exposure parameters of the CT studies and is useful in the determination of the effective dose but it is not related with the organ doses. (author)

Extra-appendiceal findings in pediatric abdominal CT for suspected appendicitis

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Halverson, Mark; Delgado, Jorge; Mahboubi, Soroosh [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States)

2014-07-15

Much has been written regarding the incidence, types, importance and management of abdominal CT incidental findings in adults, but there is a paucity of literature on incidental findings in children. We sought to determine the prevalence and characteristics of extra-appendiceal and incidental findings in pediatric abdominal CT performed for suspected appendicitis. A retrospective review was performed of abdominal CT for suspected appendicitis in a pediatric emergency department from July 2010 to June 2012. Extra-appendiceal findings were recorded. Any subsequent imaging was noted. Extra-appendiceal findings were divided into incidental findings of doubtful clinical significance, alternative diagnostic findings potentially providing a diagnosis other than appendicitis explaining the symptoms, and incidental findings that were abnormalities requiring clinical correlation and sometimes requiring further evaluation but not likely related to the patient symptoms. One hundred sixty-five children had abdominal CT for suspected appendicitis. Seventy-seven extra-appendiceal findings were found in 57 (34.5%) patients. Most findings (64 of 77) were discovered in children who did not have appendicitis. Forty-one of these findings (53%) could potentially help explain the patient's symptoms, while 30 of the findings (39%) were abnormalities that were unlikely to be related to the symptoms but required clinical correlation and sometimes further work-up. Six of the findings (8%) had doubtful or no clinical significance. Extra-appendiceal findings are common in children who undergo abdominal CT in the setting of suspected appendicitis. A significant percentage of these patients have findings that help explain their symptoms. Knowledge of the types and prevalence of these findings may help radiologists in the planning and interpretation of CT examinations in this patient population. (orig.)

Imaging in the diagnosis of pediatric urolithiasis

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Colleran, Gabrielle C.; Callahan, Michael J.; Paltiel, Harriet J.; Chow, Jeanne S. [Boston Children' s Hospital, Department of Radiology, Boston, MA (United States); Nelson, Caleb P.; Cilento, Bartley G. [Boston Children' s Hospital, Department of Urology, Boston, MA (United States); Baum, Michelle A. [Boston Children' s Hospital, Department of Nephrology, Boston, MA (United States)

2017-01-15

Pediatric urolithiasis is an important and increasingly prevalent cause of pediatric morbidity and hospital admission. Ultrasound (US) is the recommended primary imaging modality for suspected urolithiasis in children. There is, however, widespread use of CT as a first-line study for abdominal pain in many institutions involved in pediatric care. The objective of this review is to outline state-of-the-art imaging modalities and methods for diagnosing urolithiasis in children. The pediatric radiologist plays a key role in ensuring that the appropriate imaging modality is performed in the setting of suspected pediatric urolithiasis. Our proposed imaging algorithm starts with US, and describes the optimal technique and indications for the use of CT. We emphasize the importance of improved communication with a greater collaborative approach between pediatric and general radiology departments so children undergo the appropriate imaging evaluation. (orig.)

Imaging in the diagnosis of pediatric urolithiasis

International Nuclear Information System (INIS)

Colleran, Gabrielle C.; Callahan, Michael J.; Paltiel, Harriet J.; Chow, Jeanne S.; Nelson, Caleb P.; Cilento, Bartley G.; Baum, Michelle A.

2017-01-01

Pediatric urolithiasis is an important and increasingly prevalent cause of pediatric morbidity and hospital admission. Ultrasound (US) is the recommended primary imaging modality for suspected urolithiasis in children. There is, however, widespread use of CT as a first-line study for abdominal pain in many institutions involved in pediatric care. The objective of this review is to outline state-of-the-art imaging modalities and methods for diagnosing urolithiasis in children. The pediatric radiologist plays a key role in ensuring that the appropriate imaging modality is performed in the setting of suspected pediatric urolithiasis. Our proposed imaging algorithm starts with US, and describes the optimal technique and indications for the use of CT. We emphasize the importance of improved communication with a greater collaborative approach between pediatric and general radiology departments so children undergo the appropriate imaging evaluation. (orig.)

Size-appropriate radiation doses in pediatric body CT: a study of regional community adoption in the United States

International Nuclear Information System (INIS)

Hopkins, Katharine L.; Vajtai, Petra L.; Pettersson, David R.; Spinning, Kristopher; Beckett, Brooke R.; Koudelka, Caroline W.; Bardo, Dianna M.E.

2013-01-01

During the last decade, there has been a movement in the United States toward utilizing size-appropriate radiation doses for pediatric body CT, with smaller doses given to smaller patients. This study assesses community adoption of size-appropriate pediatric CT techniques. Size-specific dose estimates (SSDE) in pediatric body scans are compared between community facilities and a university children's hospital that tailors CT protocols to patient size as advocated by Image Gently. We compared 164 pediatric body scans done at community facilities (group X) with 466 children's hospital scans. Children's hospital scans were divided into two groups: A, 250 performed with established pediatric weight-based protocols and filtered back projection; B, 216 performed with addition of iterative reconstruction technique and a 60% reduction in volume CT dose index (CTDI vol ). SSDE was calculated and differences among groups were compared by regression analysis. Mean SSDE was 1.6 and 3.9 times higher in group X than in groups A and B and 2.5 times higher for group A than group B. A model adjusting for confounders confirmed significant differences between group pairs. Regional community hospitals and imaging centers have not universally adopted child-sized pediatric CT practices. More education and accountability may be necessary to achieve widespread implementation. Since even lower radiation doses are possible with iterative reconstruction technique than with filtered back projection alone, further exploration of the former is encouraged. (orig.)

Size-appropriate radiation doses in pediatric body CT: a study of regional community adoption in the United States

Energy Technology Data Exchange (ETDEWEB)

Hopkins, Katharine L.; Vajtai, Petra L. [Oregon Health and Science University, Department of Diagnostic Radiology, DC7R, Portland, OR (United States); Oregon Health and Science University, Department of Pediatrics, Portland, OR (United States); Pettersson, David R.; Spinning, Kristopher; Beckett, Brooke R. [Oregon Health and Science University, Department of Diagnostic Radiology, DC7R, Portland, OR (United States); Koudelka, Caroline W. [Oregon Health and Science University, Division of Biostatistics, Department of Public Health and Preventive Medicine, Portland, OR (United States); Bardo, Dianna M.E. [Oregon Health and Science University, Department of Diagnostic Radiology, DC7R, Portland, OR (United States); Oregon Health and Science University, Department of Cardiovascular Medicine, Portland, OR (United States)

2013-09-15

During the last decade, there has been a movement in the United States toward utilizing size-appropriate radiation doses for pediatric body CT, with smaller doses given to smaller patients. This study assesses community adoption of size-appropriate pediatric CT techniques. Size-specific dose estimates (SSDE) in pediatric body scans are compared between community facilities and a university children's hospital that tailors CT protocols to patient size as advocated by Image Gently. We compared 164 pediatric body scans done at community facilities (group X) with 466 children's hospital scans. Children's hospital scans were divided into two groups: A, 250 performed with established pediatric weight-based protocols and filtered back projection; B, 216 performed with addition of iterative reconstruction technique and a 60% reduction in volume CT dose index (CTDI{sub vol}). SSDE was calculated and differences among groups were compared by regression analysis. Mean SSDE was 1.6 and 3.9 times higher in group X than in groups A and B and 2.5 times higher for group A than group B. A model adjusting for confounders confirmed significant differences between group pairs. Regional community hospitals and imaging centers have not universally adopted child-sized pediatric CT practices. More education and accountability may be necessary to achieve widespread implementation. Since even lower radiation doses are possible with iterative reconstruction technique than with filtered back projection alone, further exploration of the former is encouraged. (orig.)

Adaptive statistical iterative reconstruction: reducing dose while preserving image quality in the pediatric head CT examination.

Science.gov (United States)

McKnight, Colin D; Watcharotone, Kuanwong; Ibrahim, Mohannad; Christodoulou, Emmanuel; Baer, Aaron H; Parmar, Hemant A

2014-08-01

Over the last decade there has been escalating concern regarding the increasing radiation exposure stemming from CT exams, particularly in children. Adaptive statistical iterative reconstruction (ASIR) is a relatively new and promising tool to reduce radiation dose while preserving image quality. While encouraging results have been found in adult head and chest and body imaging, validation of this technique in pediatric population is limited. The objective of our study was to retrospectively compare the image quality and radiation dose of pediatric head CT examinations obtained with ASIR compared to pediatric head CT examinations without ASIR in a large patient population. Retrospective analysis was performed on 82 pediatric head CT examinations. This group included 33 pediatric head CT examinations obtained with ASIR and 49 pediatric head CT examinations without ASIR. Computed tomography dose index (CTDIvol) was recorded on all examinations. Quantitative analysis consisted of standardized measurement of attenuation and the standard deviation at the bilateral centrum semiovale and cerebellar white matter to evaluate objective noise. Qualitative analysis consisted of independent assessment by two radiologists in a blinded manner of gray-white differentiation, sharpness and overall diagnostic quality. The average CTDIvol value of the ASIR group was 21.8 mGy (SD = 4.0) while the average CTDIvol for the non-ASIR group was 29.7 mGy (SD = 13.8), reflecting a statistically significant reduction in CTDIvol in the ASIR group (P ASIR group as compared to the 3- to 12-year-old non-ASIR group (21.5 mGy vs. 30.0 mGy; P = 0.004) as well as statistically significant reductions in CTDI for the >12-year-old ASIR group as compared to the >12-year-old non-ASIR group (29.7 mGy vs. 49.9 mGy; P = 0.0002). Quantitative analysis revealed no significant difference in the homogeneity of variance in the ASIR group compared to the non-ASIR group. Radiologist assessment of

Adaptive statistical iterative reconstruction: reducing dose while preserving image quality in the pediatric head CT examination

Energy Technology Data Exchange (ETDEWEB)

McKnight, Colin D.; Watcharotone, Kuanwong; Ibrahim, Mohannad; Christodoulou, Emmanuel; Baer, Aaron H.; Parmar, Hemant A. [University of Michigan, Department of Radiology, Ann Arbor, MI (United States)

2014-08-15

Over the last decade there has been escalating concern regarding the increasing radiation exposure stemming from CT exams, particularly in children. Adaptive statistical iterative reconstruction (ASIR) is a relatively new and promising tool to reduce radiation dose while preserving image quality. While encouraging results have been found in adult head and chest and body imaging, validation of this technique in pediatric population is limited. The objective of our study was to retrospectively compare the image quality and radiation dose of pediatric head CT examinations obtained with ASIR compared to pediatric head CT examinations without ASIR in a large patient population. Retrospective analysis was performed on 82 pediatric head CT examinations. This group included 33 pediatric head CT examinations obtained with ASIR and 49 pediatric head CT examinations without ASIR. Computed tomography dose index (CTDI{sub vol}) was recorded on all examinations. Quantitative analysis consisted of standardized measurement of attenuation and the standard deviation at the bilateral centrum semiovale and cerebellar white matter to evaluate objective noise. Qualitative analysis consisted of independent assessment by two radiologists in a blinded manner of gray-white differentiation, sharpness and overall diagnostic quality. The average CTDI{sub vol} value of the ASIR group was 21.8 mGy (SD = 4.0) while the average CTDI{sub vol} for the non-ASIR group was 29.7 mGy (SD = 13.8), reflecting a statistically significant reduction in CTDI{sub vol} in the ASIR group (P < 0.01). There were statistically significant reductions in CTDI for the 3- to 12-year-old ASIR group as compared to the 3- to 12-year-old non-ASIR group (21.5 mGy vs. 30.0 mGy; P = 0.004) as well as statistically significant reductions in CTDI for the >12-year-old ASIR group as compared to the >12-year-old non-ASIR group (29.7 mGy vs. 49.9 mGy; P = 0.0002). Quantitative analysis revealed no significant difference in the

Why and when to use CT in children: perspective of a pediatric emergency medicine physician

International Nuclear Information System (INIS)

Frush, Karen

2014-01-01

The Emergency Department is a risk-laden environment for clinicians caring for children. A number of factors can increase the risk of medical errors and adverse events, including lack of standardized medication dosing because of size variation in the pediatric age range, unique physical and developmental characteristics of children that affect treatment strategies, and the inability of young or non-verbal children to provide a medical history or to clearly communicate pain and other symptoms. The Emergency Department (ED) setting is often hectic and chaotic, with lots of interruptions. Many EDs lack the pediatric-specific supplies deemed essential for managing pediatric emergencies, and long hours or overnight shifts, while necessary for maintaining 24-hour emergency services, can cause provider fatigue that can lead to increased medical errors. It is in this environment that ED physicians make decisions about the use of CT scans in children, often without evidence-based guidelines to help them weigh risks and benefits. Although recent efforts have raised the awareness of the risk of exposure to radiation, many pediatric providers and families lack adequate information to guide decisions about the use of CT. Pediatricians and emergency physicians need to collaborate with radiologists to maintain current knowledge of the risks and benefits of CT scans, to advocate for pediatric protocols and evidence-based guidelines, and to engage families in decisions regarding the evaluation and treatment of pediatric patients in the Emergency Department. (orig.)

Why and when to use CT in children: perspective of a pediatric emergency medicine physician

Energy Technology Data Exchange (ETDEWEB)

Frush, Karen [Duke University School of Medicine, DUMC, Department of Pediatrics, Box 3701, Durham, NC (United States)

2014-10-15

The Emergency Department is a risk-laden environment for clinicians caring for children. A number of factors can increase the risk of medical errors and adverse events, including lack of standardized medication dosing because of size variation in the pediatric age range, unique physical and developmental characteristics of children that affect treatment strategies, and the inability of young or non-verbal children to provide a medical history or to clearly communicate pain and other symptoms. The Emergency Department (ED) setting is often hectic and chaotic, with lots of interruptions. Many EDs lack the pediatric-specific supplies deemed essential for managing pediatric emergencies, and long hours or overnight shifts, while necessary for maintaining 24-hour emergency services, can cause provider fatigue that can lead to increased medical errors. It is in this environment that ED physicians make decisions about the use of CT scans in children, often without evidence-based guidelines to help them weigh risks and benefits. Although recent efforts have raised the awareness of the risk of exposure to radiation, many pediatric providers and families lack adequate information to guide decisions about the use of CT. Pediatricians and emergency physicians need to collaborate with radiologists to maintain current knowledge of the risks and benefits of CT scans, to advocate for pediatric protocols and evidence-based guidelines, and to engage families in decisions regarding the evaluation and treatment of pediatric patients in the Emergency Department. (orig.)

Quantitative CT characterization of pediatric lung development using routine clinical imaging

Energy Technology Data Exchange (ETDEWEB)

Stein, Jill M.; Brody, Alan S.; Fleck, Robert J. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Walkup, Laura L. [Cincinnati Children' s Hospital Medical Center, Center for Pulmonary Imaging Research, Pulmonary Medicine and Radiology, Cincinnati, OH (United States); Woods, Jason C. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Cincinnati Children' s Hospital Medical Center, Center for Pulmonary Imaging Research, Pulmonary Medicine and Radiology, Cincinnati, OH (United States)

2016-12-15

The use of quantitative CT analysis in children is limited by lack of normal values of lung parenchymal attenuation. These characteristics are important because normal lung development yields significant parenchymal attenuation changes as children age. To perform quantitative characterization of normal pediatric lung parenchymal X-ray CT attenuation under routine clinical conditions in order to establish a baseline comparison to that seen in pathological lung conditions. We conducted a retrospective query of normal CT chest examinations in children ages 0-7 years from 2004 to 2014 using standard clinical protocol. During these examinations semi-automated lung parenchymal segmentation was performed to measure lung volume and mean lung attenuation. We analyzed 42 CT examinations in 39 children, ages 3 days to 83 months (mean ± standard deviation [SD] = 42 ± 27 months). Lung volume ranged 0.10-1.72 liters (L). Mean lung attenuation was much higher in children younger than 12 months, with values as high as -380 Hounsfield units (HU) in neonates (lung volume 0.10 L). Lung volume decreased to approximately -650 HU by age 2 years (lung volume 0.47 L), with subsequently slower exponential decrease toward a relatively constant value of -860 HU as age and lung volume increased. Normal lung parenchymal X-ray CT attenuation decreases with increasing lung volume and age; lung attenuation decreases rapidly in the first 2 years of age and more slowly thereafter. This change in normal lung attenuation should be taken into account as quantitative CT methods are translated to pediatric pulmonary imaging. (orig.)

Quantitative CT characterization of pediatric lung development using routine clinical imaging

International Nuclear Information System (INIS)

Stein, Jill M.; Brody, Alan S.; Fleck, Robert J.; Walkup, Laura L.; Woods, Jason C.

2016-01-01

The use of quantitative CT analysis in children is limited by lack of normal values of lung parenchymal attenuation. These characteristics are important because normal lung development yields significant parenchymal attenuation changes as children age. To perform quantitative characterization of normal pediatric lung parenchymal X-ray CT attenuation under routine clinical conditions in order to establish a baseline comparison to that seen in pathological lung conditions. We conducted a retrospective query of normal CT chest examinations in children ages 0-7 years from 2004 to 2014 using standard clinical protocol. During these examinations semi-automated lung parenchymal segmentation was performed to measure lung volume and mean lung attenuation. We analyzed 42 CT examinations in 39 children, ages 3 days to 83 months (mean ± standard deviation [SD] = 42 ± 27 months). Lung volume ranged 0.10-1.72 liters (L). Mean lung attenuation was much higher in children younger than 12 months, with values as high as -380 Hounsfield units (HU) in neonates (lung volume 0.10 L). Lung volume decreased to approximately -650 HU by age 2 years (lung volume 0.47 L), with subsequently slower exponential decrease toward a relatively constant value of -860 HU as age and lung volume increased. Normal lung parenchymal X-ray CT attenuation decreases with increasing lung volume and age; lung attenuation decreases rapidly in the first 2 years of age and more slowly thereafter. This change in normal lung attenuation should be taken into account as quantitative CT methods are translated to pediatric pulmonary imaging. (orig.)

Optimization of Protocol CT, PET-CT, whole body

International Nuclear Information System (INIS)

Gutierrez, Fredys Santos; Namias, Mauro

2013-01-01

The objective of this study was to optimize the acquisition protocols and processing existing of the CT PET/CT scanner for clinical use of Nuclear Diagnostic Center Foundation, a way to minimize the radiation dose while maintaining diagnostic image quality properly. Dosimetric data of PET / CT service were surveyed and obtained the baseline against which we compare and define strategies and modifications to develop online. We selected transaxial up to the pulmonary hilum and liver slices as the anatomical regions of interest that led to the standardization of the study

Pediatric renal leukemia: spectrum of CT imaging findings

International Nuclear Information System (INIS)

Hilmes, Melissa A.; Dillman, Jonathan R.; Mody, Rajen J.; Strouse, Peter J.

2008-01-01

The kidneys are a site of extramedullary leukemic disease that can be readily detected by CT. To demonstrate the spectrum of CT findings in children with renal leukemic involvement. Twelve children were identified retrospectively as having renal leukemic involvement by contrast-enhanced CT of the abdomen. Contrast-enhanced CT images through the kidneys of each patient were reviewed by two pediatric radiologists. Pertinent imaging findings and renal lengths were documented. The electronic medical record was accessed to obtain relevant clinical and pathologic information. Five patients with renal leukemic involvement presented with multiple bilateral low-attenuation masses, while three patients demonstrated large areas of wedge-shaped and geographic low attenuation. Four other patients presented with unique imaging findings, including a solitary unilateral low-attenuation mass, solitary bilateral low-attenuation masses, multiple bilateral low-attenuation masses including unilateral large conglomerate masses, and bilateral areas of ill-defined parenchymal low attenuation. Two patients showed unilateral nephromegaly, while eight other patients showed bilateral nephromegaly. Two patients had normal size kidneys. Two patients had elevated serum creatinine concentrations at the time of imaging. Renal leukemic involvement in children can present with a variety of CT imaging findings. Focal renal abnormalities as well as nephromegaly are frequently observed. Most commonly, renal leukemic involvement does not appear to impair renal function. (orig.)

Pediatric renal leukemia: spectrum of CT imaging findings

Energy Technology Data Exchange (ETDEWEB)

Hilmes, Melissa A. [University of Michigan Health System, C.S. Mott Children' s Hospital, Section of Pediatric Radiology, Ann Arbor, MI (United States); Vanderbilt University Children' s Hospital, Section of Pediatric Radiology, Nashville, TN (United States); Dillman, Jonathan R. [University of Michigan Health System, C.S. Mott Children' s Hospital, Section of Pediatric Radiology, Ann Arbor, MI (United States); University of Michigan Health System, Department of Radiology, Ann Arbor, MI (United States); Mody, Rajen J. [University of Michigan Health System, C.S. Mott Children' s Hospital, Division of Pediatric Hematology-Oncology and Bone Marrow Transplantation, Ann Arbor, MI (United States); Strouse, Peter J. [University of Michigan Health System, C.S. Mott Children' s Hospital, Section of Pediatric Radiology, Ann Arbor, MI (United States)

2008-04-15

The kidneys are a site of extramedullary leukemic disease that can be readily detected by CT. To demonstrate the spectrum of CT findings in children with renal leukemic involvement. Twelve children were identified retrospectively as having renal leukemic involvement by contrast-enhanced CT of the abdomen. Contrast-enhanced CT images through the kidneys of each patient were reviewed by two pediatric radiologists. Pertinent imaging findings and renal lengths were documented. The electronic medical record was accessed to obtain relevant clinical and pathologic information. Five patients with renal leukemic involvement presented with multiple bilateral low-attenuation masses, while three patients demonstrated large areas of wedge-shaped and geographic low attenuation. Four other patients presented with unique imaging findings, including a solitary unilateral low-attenuation mass, solitary bilateral low-attenuation masses, multiple bilateral low-attenuation masses including unilateral large conglomerate masses, and bilateral areas of ill-defined parenchymal low attenuation. Two patients showed unilateral nephromegaly, while eight other patients showed bilateral nephromegaly. Two patients had normal size kidneys. Two patients had elevated serum creatinine concentrations at the time of imaging. Renal leukemic involvement in children can present with a variety of CT imaging findings. Focal renal abnormalities as well as nephromegaly are frequently observed. Most commonly, renal leukemic involvement does not appear to impair renal function. (orig.)

The clinical impact of {sup 18}F-FDG PET/CT in extracranial pediatric germ cell tumors

Energy Technology Data Exchange (ETDEWEB)

Hart, Adam; Vali, Reza; Marie, Eman; Shammas, Amer [The Hospital for Sick Children and University of Toronto, Department of Medical Imaging, Nuclear Medicine, Toronto, ON (Canada); Shaikh, Furqan [The Hospital for Sick Children and University of Toronto, Division of Haematology and oncology, Toronto, ON (Canada)

2017-10-15

Extracranial germ cell tumors are an uncommon pediatric malignancy with limited information on the clinical impact of {sup 18}F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the literature. The purpose of this study was to evaluate and compare the clinical impact on management of {sup 18}F-FDG PET/CT with diagnostic computed tomography (CT) in pediatric extracranial germ cell tumor. The list of {sup 18}F-FDG PET/CT performed for extracranial germ cell tumor between May 2007 and November 2015 was obtained from the nuclear medicine database. {sup 18}F-FDG PET/CT and concurrent diagnostic CT were obtained and independently reviewed. Additionally, the patients' charts were reviewed for duration of follow-up and biopsy when available. The impact of {sup 18}F-FDG PET/CT compared with diagnostic CT on staging and patient management was demonstrated by chart review, imaging findings and follow-up studies. During the study period, 9 children (5 males and 4 females; age range: 1.6-17 years, mode age: 14 years) had 11 {sup 18}F-FDG PET/CT studies for the evaluation of germ cell tumor. Diagnostic CTs were available for comparison in 8 patients (10 {sup 18}F-FDG PET/CT studies). The average interval between diagnostic CT and PET/CT was 7.2 days (range: 0-37 days). In total, five lesions concerning for active malignancy were identified on diagnostic CT while seven were identified on PET/CT. Overall, {sup 18}F-FDG PET/CT resulted in a change in management in 3 of the 9 patients (33%). {sup 18}F-FDG PET/CT had a significant impact on the management of pediatric germ cell tumors in this retrospective study. Continued multicenter studies are required secondary to the rarity of this tumor to demonstrate the benefit of {sup 18}F-FDG PET/CT in particular clinical scenarios. (orig.)

Dose reduction in pediatric abdominal CT: use of iterative reconstruction techniques across different CT platforms

International Nuclear Information System (INIS)

Khawaja, Ranish Deedar Ali; Singh, Sarabjeet; Otrakji, Alexi; Padole, Atul; Lim, Ruth; Nimkin, Katherine; Westra, Sjirk; Kalra, Mannudeep K.; Gee, Michael S.

2015-01-01

Dose reduction in children undergoing CT scanning is an important priority for the radiology community and public at large. Drawbacks of radiation reduction are increased image noise and artifacts, which can affect image interpretation. Iterative reconstruction techniques have been developed to reduce noise and artifacts from reduced-dose CT examinations, although reconstruction algorithm, magnitude of dose reduction and effects on image quality vary. We review the reconstruction principles, radiation dose potential and effects on image quality of several iterative reconstruction techniques commonly used in clinical settings, including 3-D adaptive iterative dose reduction (AIDR-3D), adaptive statistical iterative reconstruction (ASIR), iDose, sinogram-affirmed iterative reconstruction (SAFIRE) and model-based iterative reconstruction (MBIR). We also discuss clinical applications of iterative reconstruction techniques in pediatric abdominal CT. (orig.)

Dose reduction in pediatric abdominal CT: use of iterative reconstruction techniques across different CT platforms

Energy Technology Data Exchange (ETDEWEB)

Khawaja, Ranish Deedar Ali; Singh, Sarabjeet; Otrakji, Alexi; Padole, Atul; Lim, Ruth; Nimkin, Katherine; Westra, Sjirk; Kalra, Mannudeep K.; Gee, Michael S. [MGH Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States)

2015-07-15

Dose reduction in children undergoing CT scanning is an important priority for the radiology community and public at large. Drawbacks of radiation reduction are increased image noise and artifacts, which can affect image interpretation. Iterative reconstruction techniques have been developed to reduce noise and artifacts from reduced-dose CT examinations, although reconstruction algorithm, magnitude of dose reduction and effects on image quality vary. We review the reconstruction principles, radiation dose potential and effects on image quality of several iterative reconstruction techniques commonly used in clinical settings, including 3-D adaptive iterative dose reduction (AIDR-3D), adaptive statistical iterative reconstruction (ASIR), iDose, sinogram-affirmed iterative reconstruction (SAFIRE) and model-based iterative reconstruction (MBIR). We also discuss clinical applications of iterative reconstruction techniques in pediatric abdominal CT. (orig.)

MO-E-18A-01: Imaging: Best Practices In Pediatric Imaging

International Nuclear Information System (INIS)

Willis, C; Strauss, K; MacDougall, R; Sammet, C

2014-01-01

This imaging educational program will focus on solutions to common pediatric imaging challenges. The speakers will present collective knowledge on best practices in pediatric imaging from their experience at dedicated children's hospitals. Areas of focus will include general radiography, the use of manual and automatic dose management in computed tomography, and enterprise-wide radiation dose management in the pediatric practice. The educational program will begin with a discussion of the complexities of exposure factor control in pediatric projection radiography. Following this introduction will be two lectures addressing the challenges of computed tomography (CT) protocol optimization in the pediatric population. The first will address manual CT protocol design in order to establish a managed radiation dose for any pediatric exam on any CT scanner. The second CT lecture will focus on the intricacies of automatic dose modulation in pediatric imaging with an emphasis on getting reliable results in algorithmbased technique selection. The fourth and final lecture will address the key elements needed to developing a comprehensive radiation dose management program for the pediatric environment with particular attention paid to new regulations and obligations of practicing medical physicists. Learning Objectives: To understand how general radiographic techniques can be optimized using exposure indices in order to improve pediatric radiography. To learn how to establish diagnostic dose reference levels for pediatric patients as a function of the type of examination, patient size, and individual design characteristics of the CT scanner. To learn how to predict the patient's radiation dose prior to the exam and manually adjust technique factors if necessary to match the patient's dose to the department's established dose reference levels. To learn how to utilize manufacturer-provided automatic dose modulation technology to consistently achieve patient

MO-E-18A-01: Imaging: Best Practices In Pediatric Imaging

Energy Technology Data Exchange (ETDEWEB)

Willis, C; Strauss, K; MacDougall, R; Sammet, C [MD Anderson Cancer Center, Bellaire, TX (United States)

2014-06-15

This imaging educational program will focus on solutions to common pediatric imaging challenges. The speakers will present collective knowledge on best practices in pediatric imaging from their experience at dedicated children's hospitals. Areas of focus will include general radiography, the use of manual and automatic dose management in computed tomography, and enterprise-wide radiation dose management in the pediatric practice. The educational program will begin with a discussion of the complexities of exposure factor control in pediatric projection radiography. Following this introduction will be two lectures addressing the challenges of computed tomography (CT) protocol optimization in the pediatric population. The first will address manual CT protocol design in order to establish a managed radiation dose for any pediatric exam on any CT scanner. The second CT lecture will focus on the intricacies of automatic dose modulation in pediatric imaging with an emphasis on getting reliable results in algorithmbased technique selection. The fourth and final lecture will address the key elements needed to developing a comprehensive radiation dose management program for the pediatric environment with particular attention paid to new regulations and obligations of practicing medical physicists. Learning Objectives: To understand how general radiographic techniques can be optimized using exposure indices in order to improve pediatric radiography. To learn how to establish diagnostic dose reference levels for pediatric patients as a function of the type of examination, patient size, and individual design characteristics of the CT scanner. To learn how to predict the patient's radiation dose prior to the exam and manually adjust technique factors if necessary to match the patient's dose to the department's established dose reference levels. To learn how to utilize manufacturer-provided automatic dose modulation technology to consistently achieve patient

Doses in pediatric patients undergoing chest and abdomen CT examinations. Preliminary results

International Nuclear Information System (INIS)

Jornada, Tiago S.; Silva, Teogenes A. da

2011-01-01

Computed tomography (CT) is a non-invasive method of image production that imparts significant doses to a patient, it is expected that pediatric CT examinations will increase the risk of induced cancer in children. In this study the effective doses in a five year-old child submitted to chest or abdomen CT scans were assessed for comparison purposes. The CTEXPO computed program was used with data from routine protocols of a 0 to 13 year-old children in two public hospitals in Belo Horizonte. Hospital A used a Siemens Dual-Slice unit with 80 kV, 41 mA and pitch 2 for chest or abdomen; hospital B used a Multislice GE unit with 120 kV, 45 mA and pitch 1 for chest and 120 kV, 55 mA. and pitch 1 for abdomen. Results of effective doses in a five year-old child were 1.7 and 1.0 mSv in hospital A and 9.1 and 7.2 mSv in hospital B, for chest and abdomen, respectively. Results were compared to the reference effective doses of 7.2 and 5.0 mSv for chest and abdomen respectively that were derived from the air kerma length product values given in ICRP publication 87. Results of hospital A showed that low dose exposures also can be achieved in CT scans of children. Results showed that even a hospital with a modern facility (hospital B) can provided doses higher than reference values if protocols are not adjusted for children. Preliminary results suggested that there is a room for optimizing children exposure submitted to CT scans. (author)

Practice patterns for the use of iodinated i.v. contrast media for pediatric CT studies: a survey of the Society for Pediatric Radiology.

Science.gov (United States)

Callahan, Michael J; Servaes, Sabah; Lee, Edward Y; Towbin, Alexander J; Westra, Sjirk J; Frush, Donald P

2014-04-01

There are limited data available on the use of i.v. contrast media for CT studies in the pediatric population. The purpose of this study is to determine the practice patterns of i.v. contrast media usage for pediatric CT by members of the Society for Pediatric Radiology (SPR). SPR members were surveyed regarding the use of i.v. contrast media for pediatric CT studies. Questions pertained to information required before administering i.v. contrast media, types of central catheters for injecting i.v. contrast media, injection rates based on angiocatheter size and study type, and management of i.v. contrast media extravasation. The response rate of 6% (88/1545) represented practice patterns of 26% (401/1545) of the SPR membership. Most respondents thought the following clinical information was mandatory before i.v. contrast media administration: allergy to i.v. contrast media (97%), renal insufficiency (97%), current metformin use (72%), significant allergies (61%), diabetes (54%), and asthma (52%). Most administered i.v. contrast media through nonimplanted central venous catheters (78%), implanted venous ports (78%), and peripherally inserted central catheters (72%). The most common maximum i.v. contrast media injection rates were 5.0 mL/s or greater for a 16-gauge angiocatheter, 4.0 mL/s for an 18-gauge angiocatheter, 3.0 mL/s for a 20-gauge angiocatheter, and 2.0 mL/s for a 22-gauge angiocatheter. For soft-tissue extravasation of i.v. contrast media, 95% elevate the affected extremity, 76% use ice, and 45% use heat. The results of this survey illustrate the collective opinion of a subset of SPR members relating to the use of i.v. contrast media in pediatric CT, providing guidelines for clinical histories needed before i.v. contrast media, maximum i.v. contrast injection rates for standard angiocatheters, contrast media injection rates for specific CT studies, and management of i.v. contrast media soft-tissue extravasation.

Attainment of dosimetric pediatrics grandeur to computed tomography examinations of the abdomen

International Nuclear Information System (INIS)

Jormada, Tiago S.

2013-01-01

Currently, 10% of all computerized tomography exams (CT) are made in pediatric patients. In developed countries, the practice of obtaining the dosimetric quantities (weighted index dose C w , index air kerma volumetric C vol product kerma-length P KL , CT ) and effective dose (E) in pediatric CT scans is common. In Brazil, data like these are practically nonexistent. The goal of this work is to obtain the dosimetric quantities and the dose effective in pediatric CT scans, and study its application in the optimization process. The study took place in a thermographs' Toshiba Asteion Single-Slice and a GE Brightsped's multi-slice where measurements were made with type pencil ionization chamber and a trunk's phantom of PMMA with diameter of 16 cm. In single-slice CT scanner, the results obtained for the C vol , P KL , CT and E were 18.73 mGy, 15.61 mGy and 6.87 mSv mGy.cm 343.51, respectively, whereas in multi-slice CT scanner the results were 18.81 mGy, 20.07 mGy, 441.64 mGy.cm and 8,83 mSv. There was no significant difference between the values of C w obtained already in the values of the Cvol, P KL , CT and E dose the differences between the results were quite significant. Comparing the C w and P KL , CT and with the values recommended by UCRP 87 (25 mGy for C vol and 360 mGy.cm for P KL , CT in pediatric CT scans of the abdomen), the two scanners were below reference levels for C w and not require an start on process of optimization. (author)

Evaluation of doses received by pediatric and adult patients undergoing to CT exams; Evaluacion de la dosis recibida por pacientes adultos y pediatricos en examenes de tomografia computarizada

Energy Technology Data Exchange (ETDEWEB)

Lavie, Maria F. Jimenez; Tejeda, Adalberto Machado, E-mail: felicia@cceem.sld.cu, E-mail: adalberto@cceem.sld.cu [Centro para el Control Estatal de Medicamentos, Equipos y Dispositivos Medicos (CECMED), La Habana (Cuba); Otano, Anisia; Zuniga, Dora Maya [Hospital Pediatrico Centro Habana (Cuba); Perdomo, Jorge Hing; Rodriguez, Gustavo Guadarrama [Hospital Docente Clinico Quirurgico Freyre Andrade, La Habana (Cuba)

2013-07-01

This paper aims to evaluated the dose to adult and pediatric patients due to the execution of tests CT scan of head, chest and abdomen, as well as establish a comparative analysis between these results and protocols involving employees to begin a process optimization in the practice.

Technical Note: FreeCT_ICD: An Open Source Implementation of a Model-Based Iterative Reconstruction Method using Coordinate Descent Optimization for CT Imaging Investigations.

Science.gov (United States)

Hoffman, John M; Noo, Frédéric; Young, Stefano; Hsieh, Scott S; McNitt-Gray, Michael

2018-06-01

To facilitate investigations into the impacts of acquisition and reconstruction parameters on quantitative imaging, radiomics and CAD using CT imaging, we previously released an open source implementation of a conventional weighted filtered backprojection reconstruction called FreeCT_wFBP. Our purpose was to extend that work by providing an open-source implementation of a model-based iterative reconstruction method using coordinate descent optimization, called FreeCT_ICD. Model-based iterative reconstruction offers the potential for substantial radiation dose reduction, but can impose substantial computational processing and storage requirements. FreeCT_ICD is an open source implementation of a model-based iterative reconstruction method that provides a reasonable tradeoff between these requirements. This was accomplished by adapting a previously proposed method that allows the system matrix to be stored with a reasonable memory requirement. The method amounts to describing the attenuation coefficient using rotating slices that follow the helical geometry. In the initially-proposed version, the rotating slices are themselves described using blobs. We have replaced this description by a unique model that relies on tri-linear interpolation together with the principles of Joseph's method. This model offers an improvement in memory requirement while still allowing highly accurate reconstruction for conventional CT geometries. The system matrix is stored column-wise and combined with an iterative coordinate descent (ICD) optimization. The result is FreeCT_ICD, which is a reconstruction program developed on the Linux platform using C++ libraries and the open source GNU GPL v2.0 license. The software is capable of reconstructing raw projection data of helical CT scans. In this work, the software has been described and evaluated by reconstructing datasets exported from a clinical scanner which consisted of an ACR accreditation phantom dataset and a clinical pediatric

US Emergency Department Trends in Imaging for Pediatric Nontraumatic Abdominal Pain.

Science.gov (United States)

Niles, Lauren M; Goyal, Monika K; Badolato, Gia M; Chamberlain, James M; Cohen, Joanna S

2017-10-01

To describe national emergency department (ED) trends in computed tomography (CT) and ultrasound imaging for the evaluation of pediatric nontraumatic abdominal pain from 2007 through 2014. We used data from the National Hospital Ambulatory Medical Care Survey to measure trends in CT and ultrasound use among children with nontraumatic abdominal pain. We performed multivariable logistic regression to measure the strength of the association of ED type (pediatric versus general ED) with CT and ultrasound use adjusting for potential confounding variables. Of an estimated 21.1 million ED visits for nontraumatic abdominal pain, 14.6% (95% confidence interval [CI], 13.2%-16.0%) had CT imaging only, 10.9% (95% CI, 9.7%-12.1%) had ultrasound imaging only, and 1.9% (95% CI, 1.4%-2.4%) received both CT and ultrasound. The overall use of CT and ultrasound did not significantly change over the study period ( P trend .63 and .90, respectively). CT use was lower among children treated in pediatric EDs compared with general EDs (adjusted odds ratio 0.34; 95% CI, 0.17-0.69). Conversely, ultrasound use was higher among children treated in pediatric EDs compared with general EDs (adjusted odds ratio 2.14; 95% CI, 1.29-3.55). CT imaging for pediatric patients with nontraumatic abdominal pain has plateaued since 2007 after the steady increase seen in the preceding 9 years. Among this population, an increased likelihood of CT imaging was demonstrated in general EDs compared with pediatric EDs, in which there was a higher likelihood of ultrasound imaging. Dissemination of pediatric-focused radiology protocols to general EDs may help optimize radiation exposure in children. Copyright © 2017 by the American Academy of Pediatrics.

Lung nodule detection in pediatric chest CT: quantitative relationship between image quality and radiologist performance.

Science.gov (United States)

Li, Xiang; Samei, Ehsan; Barnhart, Huiman X; Gaca, Ana Maria; Hollingsworth, Caroline L; Maxfield, Charles M; Carrico, Caroline W T; Colsher, James G; Frush, Donald P

2011-05-01

To determine the quantitative relationship between image quality and radiologist performance in detecting small lung nodules in pediatric CT. The study included clinical chest CT images of 30 pediatric patients (0-16 years) scanned at tube currents of 55-180 mA. Calibrated noise addition software was used to simulate cases at three nominal mA settings: 70, 35, and 17.5 mA, resulting in quantum noise of 7-32 Hounsfield Unit (HU). Using a validated nodule simulation technique, lung nodules with diameters of 3-5 mm and peak contrasts of 200-500 HU were inserted into the cases, which were then randomized and rated independently by four experienced pediatric radiologists for nodule presence on a continuous scale from 0 (definitely absent) to 100 (definitely present). The receiver operating characteristic (ROC) data were analyzed to quantify the relationship between diagnostic accuracy (area under the ROC curve, AUC) and image quality (the product of nodule peak contrast and displayed diameter to noise ratio, CDNR display). AUC increased rapidly from 0.70 to 0.87 when CDNR display increased from 60 to 130 mm, followed by a slow increase to 0.94 when CDNR display further increased to 257 mm. For the average nodule diameter (4 mm) and contrast (350 HU), AUC decreased from 0.93 to 0.71 with noise increased from 7 to 28 HU. We quantified the relationship between image quality and the performance of radiologists in detecting lung nodules in pediatric CT. The relationship can guide CT protocol design to achieve the desired diagnostic performance at the lowest radiation dose.

Issues specific to implementing PET-CT for pediatric oncology: what we have learned along the way

International Nuclear Information System (INIS)

Kaste, S.C.

2004-01-01

In parallel with the expansion of PET imaging to pediatric patients has been the technological development of merging state-of-the-art cross-sectional anatomic information (CT) with functional imaging (PET) into a single modality: PET-CT. Attending to the clinical, scheduling, and medical needs that are unique to imaging children and adolescents can be a challenge, particularly when instituting a single new modality. When that modality bridges two unique, previously independent methods-often previously located in two separate departmental divisions-the details and logistics required to set up a smoothly functioning process can be particularly difficult. This paper focuses on our experience in implementing PET-CT in a tertiary pediatric referral center. (orig.)

MO-DE-207-04: Imaging educational program on solutions to common pediatric imaging challenges

International Nuclear Information System (INIS)

Krishnamurthy, R.

2015-01-01

This imaging educational program will focus on solutions to common pediatric imaging challenges. The speakers will present collective knowledge on best practices in pediatric imaging from their experience at dedicated children’s hospitals. The educational program will begin with a detailed discussion of the optimal configuration of fluoroscopes for general pediatric procedures. Following this introduction will be a focused discussion on the utility of Dual Energy CT for imaging children. The third lecture will address the substantial challenge of obtaining consistent image post -processing in pediatric digital radiography. The fourth and final lecture will address best practices in pediatric MRI including a discussion of ancillary methods to reduce sedation and anesthesia rates. Learning Objectives: To learn techniques for optimizing radiation dose and image quality in pediatric fluoroscopy To become familiar with the unique challenges and applications of Dual Energy CT in pediatric imaging To learn solutions for consistent post-processing quality in pediatric digital radiography To understand the key components of an effective MRI safety and quality program for the pediatric practice

MO-DE-207-04: Imaging educational program on solutions to common pediatric imaging challenges

Energy Technology Data Exchange (ETDEWEB)

Krishnamurthy, R. [Texas Children’s Hospital: Pediatric MRI Quality, Artifacts, and Safety (United States)

2015-06-15

This imaging educational program will focus on solutions to common pediatric imaging challenges. The speakers will present collective knowledge on best practices in pediatric imaging from their experience at dedicated children’s hospitals. The educational program will begin with a detailed discussion of the optimal configuration of fluoroscopes for general pediatric procedures. Following this introduction will be a focused discussion on the utility of Dual Energy CT for imaging children. The third lecture will address the substantial challenge of obtaining consistent image post -processing in pediatric digital radiography. The fourth and final lecture will address best practices in pediatric MRI including a discussion of ancillary methods to reduce sedation and anesthesia rates. Learning Objectives: To learn techniques for optimizing radiation dose and image quality in pediatric fluoroscopy To become familiar with the unique challenges and applications of Dual Energy CT in pediatric imaging To learn solutions for consistent post-processing quality in pediatric digital radiography To understand the key components of an effective MRI safety and quality program for the pediatric practice.

Quantitative thoracic CT techniques in adults: can they be applied in the pediatric population?

Energy Technology Data Exchange (ETDEWEB)

Yoon, Soon Ho [Seoul National University Medical Research Center, Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul (Korea, Republic of); Goo, Jin Mo [Seoul National University Medical Research Center, Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul (Korea, Republic of); Seoul National University College of Medicine, Cancer Research Institute, Jongno-gu, Seoul (Korea, Republic of); Goo, Hyun Woo [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of)

2013-03-15

With the rapid evolution of the multidetector row CT technique, quantitative CT has started to be used in clinical studies for revealing a heterogeneous entity of airflow limitation in chronic obstructive pulmonary disease that is caused by a combination of lung parenchymal destruction and remodeling of the small airways in adults. There is growing evidence of a good correlation between quantitative CT findings and pathological findings, pulmonary function test results and other clinical parameters. This article provides an overview of current quantitative thoracic CT techniques used in adults, and how to translate these CT techniques to the pediatric population. (orig.)

Assessment of pediatric near-drowning victims: is there a role for cranial CT?

International Nuclear Information System (INIS)

Romano, C.; Brown, T.; Frewen, T.C.

1993-01-01

Previous studies have suggested that CT examinations of the brain in children soon after near-drowning incidents are not helpful in predicting clinical outcome and are not necessary. The clinical and CT findings of 19 pediatric near-drowning victims were reviewed for correlation with clinical and neurologic outcome. As expected, a normal initial CT scan was poorly predictive of outcome, whereas an abnormal CT scan in the initial 36 h following an immersion incident was associated with a dismal prognosis. Three children with abnormal initial CT examinations were identified and all died within 3 days of admission. A CT scan performed in the immediate near-drowning period, therefore, may be helpful in identifying some patients who have sustained severe neurologic injury. (orig.)

Pediatric CT scan usage in Japan. Results of a hospital survey

Energy Technology Data Exchange (ETDEWEB)

Ghotbi, N; Morishita, Mariko; Norimatsu, Nana; Namba, Hiroyuki; Yamashita, Shunichi [Nagasaki Univ., Graduate School of Biomedical Sciences, Nagasaki, Nagasaki (Japan); Ohtsuru, Akira [Nagasaki Univ., Hospital, Takashi Nagai Memorial International Hibakusha Medical Center, Nagasaki, Nagaski (Japan); Ogawa, Yoji; Uetani, Masataka; Moriuchi, Hiroyuki [Nagasaki Univ., Hospital, Nagasaki, Nagasaki (Japan)

2006-10-15

The aim of this study was to examine the usage parameters of diagnostic computed tomography (CT) in children because of concerns of possible overuse in Japanese hospitals, including the ''technical'' CT exposure settings and the ''clinical'' grounds for CT requests. We examined the methodology at the radiology department to reduce radiation exposure to children and performed a retrospective study on pediatric CT requests during a 1-year period at Nagasaki University Hospital. The parameters of diagnostic CT usage for minor head trauma and acute appendicitis were studied in detail. CT radiation dose settings are adjusted for children based on guidelines issued by the Japan Radiological Society, with few limitations. CT requests were made for 62% of minor head trauma cases and 76% of cases clinically suspected to be acute appendicitis. These figures are considerably higher than those reported by studies in the United Kingdom, Canada, or the United States. No specific guidelines are advocated regarding CT usage for minor head trauma. The diagnosis of acute appendicitis in children is almost routinely referred for confirmation'' by CT. CT radiation risks to children at Japanese hospitals need to be considered more seriously. Physicians should be encouraged to follow diagnostic algorithms that help avoid unnecessary CT usage in children. (author)

Pediatric CT scan usage in Japan. Results of a hospital survey

International Nuclear Information System (INIS)

Ghotbi, N.; Morishita, Mariko; Norimatsu, Nana; Namba, Hiroyuki; Yamashita, Shunichi; Ohtsuru, Akira; Ogawa, Yoji; Uetani, Masataka; Moriuchi, Hiroyuki

2006-01-01

The aim of this study was to examine the usage parameters of diagnostic computed tomography (CT) in children because of concerns of possible overuse in Japanese hospitals, including the ''technical'' CT exposure settings and the ''clinical'' grounds for CT requests. We examined the methodology at the radiology department to reduce radiation exposure to children and performed a retrospective study on pediatric CT requests during a 1-year period at Nagasaki University Hospital. The parameters of diagnostic CT usage for minor head trauma and acute appendicitis were studied in detail. CT radiation dose settings are adjusted for children based on guidelines issued by the Japan Radiological Society, with few limitations. CT requests were made for 62% of minor head trauma cases and 76% of cases clinically suspected to be acute appendicitis. These figures are considerably higher than those reported by studies in the United Kingdom, Canada, or the United States. No specific guidelines are advocated regarding CT usage for minor head trauma. The diagnosis of acute appendicitis in children is almost routinely referred for confirmation'' by CT. CT radiation risks to children at Japanese hospitals need to be considered more seriously. Physicians should be encouraged to follow diagnostic algorithms that help avoid unnecessary CT usage in children. (author)

Radiologic protection in pediatric radiology: ICRP recommendations

International Nuclear Information System (INIS)

Sanchez, Ramon; Khong, Pek-Lan; Ringertz, Hans

2013-01-01

ICRP has provided an updated overview of radiation protection principles in pediatric radiology. The authors recommend that staff, radiologists, medical physicists and vendors involved in pediatric radiology read this document. For conventional radiography, the report gives advice on patient positioning, immobilization, shielding and appropriate exposure conditions. It describes extensively the use of pulsed fluoroscopy, the importance of limiting fluoroscopy time, and how shielding and geometry must be used to avoid unnecessary radiation to the patient and operator. Furthermore, the use of fluoroscopy in interventional procedures with emphasis on dose reduction to patients and staff is discussed in light of the increasing frequency, complexity and length ofthe procedures. CT is the main reason that medical imaging in several developed countries is the highest annual per capita effective radiation dose from man-made sources. The ICRP report gives extensive descriptions of how CT protocols can be optimized to minimize radiation exposure in pediatric patients. The importance of balancing image quality with acceptable noise in pediatric imaging and the controversies regarding the use of protective shielding in CT are also discussed.

Radiation dose and cancer risk from pediatric CT examinations on 64-slice CT: A phantom study

International Nuclear Information System (INIS)

Feng Shiting; Law, Martin Wai-Ming; Huang Bingsheng; Ng, Sherry; Li Ziping; Meng Quanfei; Khong, Pek-Lan

2010-01-01

Objective: To measure the radiation dose from CT scans in an anthropomorphic phantom using a 64-slice MDCT, and to estimate the associated cancer risk. Materials and methods: Organ doses were measured with a 5-year-old phantom and thermoluminescent dosimeters. Four protocols; head CT, thorax CT, abdomen CT and pelvis CT were studied. Cancer risks, in the form of lifetime attributable risk (LAR) of cancer incidence, were estimated by linear extrapolation using the organ radiation doses and the LAR data. Results: The effective doses for head, thorax, abdomen and pelvis CT, were 0.7 mSv, 3.5 mSv, 3.0 mSv, 1.3 mSv respectively. The organs with the highest dose were; for head CT, salivary gland (22.33 mGy); for thorax CT, breast (7.89 mGy); for abdomen CT, colon (6.62 mGy); for pelvis CT, bladder (4.28 mGy). The corresponding LARs for boys and girls were 0.015-0.053% and 0.034-0.155% respectively. The organs with highest LARs were; for head CT, thyroid gland (0.003% for boys, 0.015% for girls); for thorax CT, lung for boys (0.014%) and breast for girls (0.069%); for abdomen CT, colon for boys (0.017%) and lung for girls (0.016%); for pelvis CT, bladder for both boys and girls (0.008%). Conclusion: The effective doses from these common pediatric CT examinations ranged from 0.7 mSv to 3.5 mSv and the associated lifetime cancer risks were found to be up to 0.16%, with some organs of higher radiosensitivity including breast, thyroid gland, colon and lungs.

Cross-sectional imaging with CT and/or MRI of pediatric chest tumors

International Nuclear Information System (INIS)

Wyttenbach, R.; Vock, P.; Tschaeppeler, H.

1998-01-01

The purpose of this study was to provide an overview of the spectrum of pediatric chest masses, to present the results of cross-sectional imaging with CT and/or MRI, and to define diagnostic criteria to limit differential diagnosis. Seventy-eight children with thoracic mass lesions were retrospectively evaluated using CT (72 patients) and/or MR imaging (12 patients). All masses were evaluated for tissue characteristics (attenuation values or signal intensity, enhancement, and calcification) and were differentiated according to age, gender, location, and etiology. Twenty-eight of 38 (74 %) mediastinal masses were malignant (neuroblastoma, malignant lymphoma). Thirty of 38 (79 %) pulmonary masses were metastatic in origin, all with an already known primary tumor (osteosarcoma, Wilms tumor). With one exception, all remaining pulmonary lesions were benign. Seventeen of 21 (81 %) chest wall lesions were malignant (Ewing sarcoma, primitive neuroectodermal tumor). The majority of mediastinal and chest wall tumors in children is malignant. Lung lesions are usually benign, unless a known extrapulmonary tumor suggests pulmonary metastases. Cross-sectional imaging with CT and/or MRI allows narrowing of the differential diagnosis of pediatric chest masses substantially by defining the origin and tissue characteristics. Magnetic resonance imaging is preferred for posterior mediastinal lesions, whereas CT should be used for pulmonary lesions. For the residual locations both modalities are complementary. (orig.)

Evaluation of radiation dose and image quality of CT scan for whole-body pediatric PET/CT: A phantom study

Energy Technology Data Exchange (ETDEWEB)

Yang, Ching-Ching, E-mail: cyang@tccn.edu.tw [Department of Medical Imaging and Radiological Sciences, Tzu-Chi College of Technology, 970, Hualien, Taiwan (China); Liu, Shu-Hsin [Department of Nuclear Medicine, Buddhist Tzu-Chi General Hospital, 970, Hualien, Taiwan and Department of Medical Imaging and Radiological Sciences, Tzu-Chi College of Technology, 970, Hualien, Taiwan (China); Mok, Greta S. P. [Biomedical Imaging Laboratory, Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau (China); Wu, Tung-Hsin [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, 112, Taipei, Taiwan (China)

2014-09-15

Purpose: This study aimed to tailor the CT imaging protocols for pediatric patients undergoing whole-body PET/CT examinations with appropriate attention to radiation exposure while maintaining adequate image quality for anatomic delineation of PET findings and attenuation correction of PET emission data. Methods: The measurements were made by using three anthropomorphic phantoms representative of 1-, 5-, and 10-year-old children with tube voltages of 80, 100, and 120 kVp, tube currents of 10, 40, 80, and 120 mA, and exposure time of 0.5 s at 1.75:1 pitch. Radiation dose estimates were derived from the dose-length product and were used to calculate risk estimates for radiation-induced cancer. The influence of image noise on image contrast and attenuation map for CT scans were evaluated based on Pearson's correlation coefficient and covariance, respectively. Multiple linear regression methods were used to investigate the effects of patient age, tube voltage, and tube current on radiation-induced cancer risk and image noise for CT scans. Results: The effective dose obtained using three anthropomorphic phantoms and 12 combinations of kVp and mA ranged from 0.09 to 4.08 mSv. Based on our results, CT scans acquired with 80 kVp/60 mA, 80 kVp/80 mA, and 100 kVp/60 mA could be performed on 1-, 5-, and 10-year-old children, respectively, to minimize cancer risk due to CT scans while maintaining the accuracy of attenuation map and CT image contrast. The effective doses of the proposed protocols for 1-, 5- and 10-year-old children were 0.65, 0.86, and 1.065 mSv, respectively. Conclusions: Low-dose pediatric CT protocols were proposed to balance the tradeoff between radiation-induced cancer risk and image quality for patients ranging in age from 1 to 10 years old undergoing whole-body PET/CT examinations.

CT and MRI appearances and radiologic staging of pediatric renal cell carcinoma

Energy Technology Data Exchange (ETDEWEB)

Downey, Ryan T. [University of Michigan Health System, Department of Radiology, Ann Arbor, MI (United States); Dillman, Jonathan R.; Ladino-Torres, Maria F.; Strouse, Peter J. [University of Michigan Health System, Section of Pediatric Radiology, C.S. Mott Children' s Hospital, Department of Radiology, Ann Arbor, MI (United States); McHugh, Jonathan B. [University of Michigan Health System, Department of Pathology, Ann Arbor, MI (United States); Ehrlich, Peter F. [University of Michigan Health System, Department of Surgery, Section of Pediatric Surgery, Ann Arbor, MI (United States)

2012-04-15

Renal cell carcinoma (RCC) is an uncommon but noteworthy primary pediatric renal malignancy. There is a paucity of published data regarding the CT/MRI appearances and accuracy of pretreatment radiologic staging of this form of cancer in children. To review the various CT/MRI appearances of pediatric RCC and assess the accuracy of pretreatment radiologic staging using these imaging modalities. Institutional Departments of Pathology and Radiology records were searched from 1995 through 2010 for children (younger than 18 years of age) with RCC. Available pretreatment contrast-enhanced abdominopelvic CT and MRI examinations were reviewed by two radiologists. Pertinent imaging findings were documented by consensus, and correlation was made between radiologic and surgicopathological TNM staging. Pretreatment imaging studies from 10 RCCs in nine children (four girls and five boys; mean age 12.9 years) were reviewed. The mean size of the primary tumor was 6.2 cm (range, 1.5-12.6 cm). Ninety percent of RCCs demonstrated heterogeneous postcontrast enhancement. Fifty percent of masses had associated hemorrhage, while 40% contained internal calcification. Regarding TNM staging, N staging was correct for 10 of 10 tumors, while M staging was correct for 10 of 10 tumors. Imaging correctly staged only 4 of 10 tumors with respect to T stage. Radiologic and surgicopathological overall staging were concordant for 8 of 10 tumors. Pediatric RCCs typically present as large, heterogeneous masses, and they commonly hemorrhage and contain internal calcification. Radiologic and surgicopathological overall TNM staging are frequently concordant, although radiologic T staging is often incorrect. (orig.)

PET/CT versus bone marrow biopsy in the initial evaluation of bone marrow infiltration in various pediatric malignancies.

Science.gov (United States)

Zapata, Claudia P; Cuglievan, Branko; Zapata, Catalina M; Olavarrieta, Raquel; Raskin, Scott; Desai, Kavita; De Angulo, Guillermo

2018-02-01

Accurate staging is essential in the prognosis and management of pediatric malignancies. Current protocols require screening for marrow infiltration with bone marrow biopsy (BMB) as the gold standard. Positron emission tomography-computed tomography (PET-CT) is commonly used to complete the staging process and can also be used to evaluate marrow infiltration. To compare PET-CT and BMB in the initial evaluation of bone marrow infiltration in pediatric cancers. We retrospectively reviewed new cases of EWS, rhabdomyosarcoma, neuroblastoma, and lymphoma diagnosed between January 2009 and October 2014. Each case had undergone both PET-CT and BMB within 4 weeks without treatment in the interval between screening modalities. We reviewed 69 cases. Bone marrow infiltration was demonstrated in 34 cases by PET-CT and in 18 cases by BMB. The sensitivity and negative predictive value of PET-CT were both 100%. Interestingly, the cases in which infiltration was not detected on BMB had an abnormal marrow signal on PET-CT focal or distant to iliac crest. PET-CT has a high sensitivity when assessing marrow infiltration in pediatric malignancies. Advances in radiologic modalities may obviate the use of invasive, painful, and costly procedures like BMB. Furthermore, biopsy results are limited by insufficient tissue or the degree of marrow infiltration (diffuse vs. focal disease). PET-CT can improve the precision of biopsy when used as a guiding tool. This study proposes the use of PET-CT as first-line screening for bone marrow infiltration to improve the accuracy of staging in new diagnoses. © 2017 Wiley Periodicals, Inc.

Detection of Airway Anomalies in?Pediatric?Patients with Cardiovascular Anomalies with Low Dose Prospective ECG-Gated Dual-Source CT

OpenAIRE

Jiao, Hui; Xu, Zhuodong; Wu, Lebin; Cheng, Zhaoping; Ji, Xiaopeng; Zhong, Hai; Meng, Chen

2013-01-01

OBJECTIVES: To assess the feasibility of low-dose prospective ECG-gated dual-source CT (DSCT) in detecting airway anomalies in pediatric patients with cardiovascular anomalies compared with flexible tracheobronchoscopy (FTB). METHODS: 33 pediatrics with respiratory symptoms who had been revealed cardiovascular anomalies by transthoracic echocardiography underwent FTB and contrast material-enhanced prospective ECG-triggering CT were enrolled. The study was approved by our institution review bo...

MO-PIS-Exhibit Hall-01: Imaging: CT Dose Optimization Technologies I

Energy Technology Data Exchange (ETDEWEB)

Denison, K; Smith, S [GE Healthcare, Waukesha, WI (United States)

2014-06-15

DICOM Radiation Dose Structured Report (RDSR) generates a dose report at the conclusion of every examination. Dose Check preemptively notifies CT operators when scan parameters exceed user-defined dose thresholds. DoseWatch is an information technology application providing vendor-agnostic dose tracking and analysis for CT (and all other diagnostic x-ray modalities) SnapShot Pulse improves coronary CTA dose management. VolumeShuttle uses two acquisitions to increase coverage, decrease dose, and conserve on contrast administration. Color-Coding for Kids applies the Broselow-Luten Pediatric System to facilitate pediatric emergency care and reduce medical errors. FeatherLight achieves dose optimization through pediatric procedure-based protocols. Adventure Series scanners provide a child-friendly imaging environment promoting patient cooperation with resultant reduction in retakes and patient motion. Philips CT Dose Optimization Tools and Advanced Reconstruction Presentation Time: 11:45 ‘ 12:15 PM The first part of the talk will cover “Dose Reduction and Dose Optimization Technologies” present in Philips CT Scanners. The main Technologies to be presented include: DoseRight and tube current modulation (DoseRight, Z-DOM, 3D-DOM, DoseRight Cardiac) Special acquisition modes Beam filtration and beam shapers Eclipse collimator and ClearRay collimator NanoPanel detector DoseRight will cover automatic tube current selection that automatically adjusts the dose for the individual patient. The presentation will explore the modulation techniques currently employed in Philips CT scanners and will include the algorithmic concepts as well as illustrative examples. Modulation and current selection technologies to be covered include the Automatic Current Selection component of DoseRight, ZDOM longitudinal dose modulation, 3D-DOM (combination of longitudinal and rotational dose modulation), Cardiac Dose right (an ECG based dose modulation scheme), and the DoseRight Index (DRI) IQ

MO-PIS-Exhibit Hall-01: Imaging: CT Dose Optimization Technologies I

International Nuclear Information System (INIS)

Denison, K; Smith, S

2014-01-01

DICOM Radiation Dose Structured Report (RDSR) generates a dose report at the conclusion of every examination. Dose Check preemptively notifies CT operators when scan parameters exceed user-defined dose thresholds. DoseWatch is an information technology application providing vendor-agnostic dose tracking and analysis for CT (and all other diagnostic x-ray modalities) SnapShot Pulse improves coronary CTA dose management. VolumeShuttle uses two acquisitions to increase coverage, decrease dose, and conserve on contrast administration. Color-Coding for Kids applies the Broselow-Luten Pediatric System to facilitate pediatric emergency care and reduce medical errors. FeatherLight achieves dose optimization through pediatric procedure-based protocols. Adventure Series scanners provide a child-friendly imaging environment promoting patient cooperation with resultant reduction in retakes and patient motion. Philips CT Dose Optimization Tools and Advanced Reconstruction Presentation Time: 11:45 ‘ 12:15 PM The first part of the talk will cover “Dose Reduction and Dose Optimization Technologies” present in Philips CT Scanners. The main Technologies to be presented include: DoseRight and tube current modulation (DoseRight, Z-DOM, 3D-DOM, DoseRight Cardiac) Special acquisition modes Beam filtration and beam shapers Eclipse collimator and ClearRay collimator NanoPanel detector DoseRight will cover automatic tube current selection that automatically adjusts the dose for the individual patient. The presentation will explore the modulation techniques currently employed in Philips CT scanners and will include the algorithmic concepts as well as illustrative examples. Modulation and current selection technologies to be covered include the Automatic Current Selection component of DoseRight, ZDOM longitudinal dose modulation, 3D-DOM (combination of longitudinal and rotational dose modulation), Cardiac Dose right (an ECG based dose modulation scheme), and the DoseRight Index (DRI) IQ

Boots on the ground: how to influence your local radiology departments to use appropriate CT dose

International Nuclear Information System (INIS)

Slovis, Thomas L.

2014-01-01

Most pediatric CT examinations (as many as 85%) are performed at non-pediatric-focused facilities. In contrast to children's hospitals and pediatric emergency departments, the number of CT examinations is increasing at these non-pediatric facilities. Compliance with diagnostic reference levels (DRLs) for dose has been shown to be poor at several metropolitan centers. Several high-yield interventions are worth exploring in an effort to achieve more optimal imaging care of children, such as electronic transfer of images to prevent duplication of examinations as well as personal feedback to referring institutions on dose, indications and quality by the pediatric referral center. (orig.)

Radiation dose and image quality in pediatric chest CT: effects of iterative reconstruction in normal weight and overweight children

International Nuclear Information System (INIS)

Yoon, Haesung; Kim, Myung-Joon; Shin, Hyun Joo; Kim, Hyun Gi; Lee, Mi-Jung; Yoon, Choon-Sik; Choi, Jiin

2015-01-01

New CT reconstruction techniques may help reduce the burden of ionizing radiation. To quantify radiation dose reduction when performing pediatric chest CT using a low-dose protocol and 50% adaptive statistical iterative reconstruction (ASIR) compared with age/gender-matched chest CT using a conventional dose protocol and reconstructed with filtered back projection (control group) and to determine its effect on image quality in normal weight and overweight children. We retrospectively reviewed 40 pediatric chest CT (M:F = 21:19; range: 0.1-17 years) in both groups. Radiation dose was compared between the two groups using paired Student's t-test. Image quality including noise, sharpness, artifacts and diagnostic acceptability was subjectively assessed by three pediatric radiologists using a four-point scale (superior, average, suboptimal, unacceptable). Eight children in the ASIR group and seven in the control group were overweight. All radiation dose parameters were significantly lower in the ASIR group (P < 0.01) with a greater than 57% dose reduction in overweight children. Image noise was higher in the ASIR group in both normal weight and overweight children. Only one scan in the ASIR group (1/40, 2.5%) was rated as diagnostically suboptimal and there was no unacceptable study. In both normal weight and overweight children, the ASIR technique is associated with a greater than 57% mean dose reduction, without significantly impacting diagnostic image quality in pediatric chest CT examinations. However, CT scans in overweight children may have a greater noise level, even when using the ASIR technique. (orig.)

Radiation dose and image quality in pediatric chest CT: effects of iterative reconstruction in normal weight and overweight children

Energy Technology Data Exchange (ETDEWEB)

Yoon, Haesung; Kim, Myung-Joon; Shin, Hyun Joo; Kim, Hyun Gi; Lee, Mi-Jung [Yonsei University College of Medicine, Department of Radiology and Research Institute of Radiological Science, Severance Children' s Hospital, Seoul (Korea, Republic of); Yoon, Choon-Sik [Yonsei University College of Medicine, Department of Radiology, Gangnam Severance Hospital, Seoul (Korea, Republic of); Choi, Jiin [Yonsei University College of Medicine, Biostatistics Collaboration Unit, Seoul (Korea, Republic of)

2015-03-01

New CT reconstruction techniques may help reduce the burden of ionizing radiation. To quantify radiation dose reduction when performing pediatric chest CT using a low-dose protocol and 50% adaptive statistical iterative reconstruction (ASIR) compared with age/gender-matched chest CT using a conventional dose protocol and reconstructed with filtered back projection (control group) and to determine its effect on image quality in normal weight and overweight children. We retrospectively reviewed 40 pediatric chest CT (M:F = 21:19; range: 0.1-17 years) in both groups. Radiation dose was compared between the two groups using paired Student's t-test. Image quality including noise, sharpness, artifacts and diagnostic acceptability was subjectively assessed by three pediatric radiologists using a four-point scale (superior, average, suboptimal, unacceptable). Eight children in the ASIR group and seven in the control group were overweight. All radiation dose parameters were significantly lower in the ASIR group (P < 0.01) with a greater than 57% dose reduction in overweight children. Image noise was higher in the ASIR group in both normal weight and overweight children. Only one scan in the ASIR group (1/40, 2.5%) was rated as diagnostically suboptimal and there was no unacceptable study. In both normal weight and overweight children, the ASIR technique is associated with a greater than 57% mean dose reduction, without significantly impacting diagnostic image quality in pediatric chest CT examinations. However, CT scans in overweight children may have a greater noise level, even when using the ASIR technique. (orig.)

Adaptive statistical iterative reconstruction use for radiation dose reduction in pediatric lower-extremity CT: impact on diagnostic image quality.

Science.gov (United States)

Shah, Amisha; Rees, Mitchell; Kar, Erica; Bolton, Kimberly; Lee, Vincent; Panigrahy, Ashok

2018-06-01

For the past several years, increased levels of imaging radiation and cumulative radiation to children has been a significant concern. Although several measures have been taken to reduce radiation dose during computed tomography (CT) scan, the newer dose reduction software adaptive statistical iterative reconstruction (ASIR) has been an effective technique in reducing radiation dose. To our knowledge, no studies are published that assess the effect of ASIR on extremity CT scans in children. To compare radiation dose, image noise, and subjective image quality in pediatric lower extremity CT scans acquired with and without ASIR. The study group consisted of 53 patients imaged on a CT scanner equipped with ASIR software. The control group consisted of 37 patients whose CT images were acquired without ASIR. Image noise, Computed Tomography Dose Index (CTDI) and dose length product (DLP) were measured. Two pediatric radiologists rated the studies in subjective categories: image sharpness, noise, diagnostic acceptability, and artifacts. The CTDI (p value = 0.0184) and DLP (p value ASIR compared with non-ASIR studies. However, the subjective ratings for sharpness (p ASIR images (p ASIR CT studies. Adaptive statistical iterative reconstruction reduces radiation dose for lower extremity CTs in children, but at the expense of diagnostic imaging quality. Further studies are warranted to determine the specific utility of ASIR for pediatric musculoskeletal CT imaging.

Recurrent pediatric mesenteroaxial gastric volvulus: case report focusing on ultrasonographic and CT findings

Energy Technology Data Exchange (ETDEWEB)

Choi, Hyun Jun; Yun, Jun Hyun; Choi, Ji Hyeo; Im, Ju Hyun; Kim, Se Jong; Park, Byung Ran [Gwangju Christian Hospital, Gwangju (Korea, Republic of)

2004-11-01

Gastric volvulus is a rare condition, and it is classified as the organoaxial or mesentericaxial type according to the axis of rotation. We experienced 1 case of pediatric recurrent mesenteroaxial gastric volvulus and we report here the ultrasonographic and CT findings.

Recurrent pediatric mesenteroaxial gastric volvulus: case report focusing on ultrasonographic and CT findings

International Nuclear Information System (INIS)

Choi, Hyun Jun; Yun, Jun Hyun; Choi, Ji Hyeo; Im, Ju Hyun; Kim, Se Jong; Park, Byung Ran

2004-01-01

Gastric volvulus is a rare condition, and it is classified as the organoaxial or mesentericaxial type according to the axis of rotation. We experienced 1 case of pediatric recurrent mesenteroaxial gastric volvulus and we report here the ultrasonographic and CT findings

Potential benefit of the CT adaptive statistical iterative reconstruction method for pediatric cardiac diagnosis

Science.gov (United States)

Miéville, Frédéric A.; Ayestaran, Paul; Argaud, Christophe; Rizzo, Elena; Ou, Phalla; Brunelle, Francis; Gudinchet, François; Bochud, François; Verdun, Francis R.

2010-04-01

Adaptive Statistical Iterative Reconstruction (ASIR) is a new imaging reconstruction technique recently introduced by General Electric (GE). This technique, when combined with a conventional filtered back-projection (FBP) approach, is able to improve the image noise reduction. To quantify the benefits provided on the image quality and the dose reduction by the ASIR method with respect to the pure FBP one, the standard deviation (SD), the modulation transfer function (MTF), the noise power spectrum (NPS), the image uniformity and the noise homogeneity were examined. Measurements were performed on a control quality phantom when varying the CT dose index (CTDIvol) and the reconstruction kernels. A 64-MDCT was employed and raw data were reconstructed with different percentages of ASIR on a CT console dedicated for ASIR reconstruction. Three radiologists also assessed a cardiac pediatric exam reconstructed with different ASIR percentages using the visual grading analysis (VGA) method. For the standard, soft and bone reconstruction kernels, the SD is reduced when the ASIR percentage increases up to 100% with a higher benefit for low CTDIvol. MTF medium frequencies were slightly enhanced and modifications of the NPS shape curve were observed. However for the pediatric cardiac CT exam, VGA scores indicate an upper limit of the ASIR benefit. 40% of ASIR was observed as the best trade-off between noise reduction and clinical realism of organ images. Using phantom results, 40% of ASIR corresponded to an estimated dose reduction of 30% under pediatric cardiac protocol conditions. In spite of this discrepancy between phantom and clinical results, the ASIR method is as an important option when considering the reduction of radiation dose, especially for pediatric patients.

Brain tumors and CT scan in infants and children, (1). The impact on pediatric neuroradiology

Energy Technology Data Exchange (ETDEWEB)

Ohi, S; Velasco, J M [Northwestern Univ., Chicago, IL (USA). Medical School

1980-10-01

The dramatic change in the neuroradiological procedures have been noted after CT scan was introduced in the last several years. Remarkable decreasing numbers of angiographic, pneumoencephalographic and other invasive neuroradiologic studies as well as nuclear brain scan were also found in the pediatric neuroradiology. The authors analyzed the total numbers of these studies performed in the last several years in pediatric neurological/neurosurgical practice in the light of the impact of CT scan especially in the diagnostic procedures and treatments of brain tumor in children. Although the number of these procedures decreased up to 49% in plain skull X-ray, 54% in cerebral angiography, 70% in pneumoencephalography/ventriculography and 79% in nuclear brain scan after CT scan was installed in our results, it is extremely important to renew understanding of those characteristics in each special procedures. Cerebral angiography as well as pneumoencephalography may give the surgeon more precise ideas of the anatomical relationship between the lesion and other normal structures, especially in the posterior fossa tumor in which CT scan occassionally demonstrates only a gross finding. A case with false negative result and another case with a complicated anatomical structure in CT scan were presented. The significance of cerebral angiography and other invasive studies in the diagnosis and follow up of brain tumor in CT scan were discussed.

Iohexol for contrast enhancement of bowel in pediatric abdominal CT

International Nuclear Information System (INIS)

Smevik, B.; Westvik, J.

1990-01-01

Abdominal CT scans from 160 examinations performed on pediatric patients using iohexol 2 percent as contrast medium for bowel enhancement were evaluated retrospectively. When diluted with a beverage of the child's choice, iohexol has a neutral taste and cannot be detected, and 139 out of 142 patients drank the full amount of dilute contrast offered to them. The enhancement of bowel in the area of interest was graded as good (58%), reasonable (23%), or poor (19%). The contrast medium was prepared from leftovers from our angiocardiography studies. We conclude that the use of water-soluble contrast medium in a low concentration is a safe and cost-effective way of facilitating ingesion of sufficient amounts of the medium in oncologic pediatric patients undergoing cytotoxic and/or radiation treatment. (orig.)

Boots on the ground: how to influence your local radiology departments to use appropriate CT dose

Energy Technology Data Exchange (ETDEWEB)

Slovis, Thomas L. [Wayne State University School of Medicine, Children' s Hospital of Michigan, Department of Radiology, Detroit, MI (United States)

2014-10-15

Most pediatric CT examinations (as many as 85%) are performed at non-pediatric-focused facilities. In contrast to children's hospitals and pediatric emergency departments, the number of CT examinations is increasing at these non-pediatric facilities. Compliance with diagnostic reference levels (DRLs) for dose has been shown to be poor at several metropolitan centers. Several high-yield interventions are worth exploring in an effort to achieve more optimal imaging care of children, such as electronic transfer of images to prevent duplication of examinations as well as personal feedback to referring institutions on dose, indications and quality by the pediatric referral center. (orig.)

Ultra-high pitch chest computed tomography at 70 kVp tube voltage in an anthropomorphic pediatric phantom and non-sedated pediatric patients: Initial experience with 3rd generation dual-source CT.

Science.gov (United States)

Hagelstein, Claudia; Henzler, Thomas; Haubenreisser, Holger; Meyer, Mathias; Sudarski, Sonja; Schoenberg, Stefan O; Neff, K Wolfgang; Weis, Meike

2016-12-01

Minimizing radiation dose while at the same time preserving image quality is of particular importance in pediatric chest CT. Very recently, CT imaging with a tube voltage of 70 kVp has become clinically available. However, image noise is inversely proportional to the tube voltage. We aimed to investigate radiation dose and image quality of pediatric chest CT performed at 70 kVp in an anthropomorphic pediatric phantom as well as in clinical patients. An anthropomorphic pediatric phantom, which resembles a one-year-old child in physiognomy, was scanned on the 3 rd generation dual-source CT (DSCT) system at 70 kVp and 80 kVp and a fixed ultra low tube-current of 8 mAs to solely evaluate the impact of lowering tube voltage. After the phantom measurements, 18 pediatric patients (mean 29.5 months; range 1-91 months; 21 examinations) underwent 3.2 high-pitch chest CT on the same DSCT system at 70 kVp tube voltage without any sedation. Radiation dose and presence of motion artifacts was compared to a retrospectively identified patient cohort examined at 80 kVp on a 16-slice single-source-CT (SSCT; n=15; 14/15 with sedation; mean 30.7 months; range 0-96 months; pitch=1.5) or on a 2 nd generation DSCT without any sedation (n=6; mean 32.8 months; range 4-61 months; pitch=3.2). Radiation dose in the phantom scans was reduced by approximately 40% when using a tube voltage of 70 kVp instead of 80 kVp. In the pediatric patient group examined at 70 kVp age-specific effective dose (ED; mean 0.5±0.2 mSv) was significantly lower when compared to the retrospective cohort scanned at 80 kVp on the 16-slice-SSCT (mean ED: 1.0±0.3 mSv; pCT examinations showed any motion artifacts whereas 13/15 examinations of the retrospective patient cohort scanned at 80 kVp with a pitch of 1.5 showed motion artifacts. 3.2 high-pitch chest CT performed with 70 kVp significantly reduces radiation dose when compared to 80 kVp while at the same time provides good image quality without any motion artifacts

Cone beam CT for organs motion evaluation in pediatric abdominal neuroblastoma

International Nuclear Information System (INIS)

Nazmy, Mohamed Soliman; Khafaga, Yasser; Mousa, Amr; Khalil, Ehab

2012-01-01

Background and purpose: To quantify the organ motion relative to bone in different breathing states in pediatric neuroblastoma using cone beam CT (CBCT) for better definition of the planning margins during abdominal IMRT. Methods and materials: Forty-two datasets of kV CBCT for 9 pediatric patients with abdominal neuroblastoma treated with IMRT were evaluated. Organs positions on planning CT scan were considered the reference position against which organs and target motions were evaluated. The position of the kidneys and the liver was assessed in all scans. The target movement was evaluated in four patients who were treated for gross residual disease. Results: The mean age of the patients was 4.1 ± 1.6 years. The range of target movement in the craniocaudal direction (CC) was 5 mm. In the CC direction, the range of movement was 10 mm for the right kidney, and 8 mm for the left kidney. Similarly, the liver upper edge range of motion was 11 mm while the lower edge range of motion was 13 mm. Conclusions: With the use of daily CBCT we may be able to reduce the PTV margin. If CBCT is not used daily, a wider margin is needed.

Clinical significance of pretreatment FDG PET/CT IN MOBG-avid pediatric neuroblastoma

Energy Technology Data Exchange (ETDEWEB)

Kang, Seo Young; Kim, Yong Il; Cheon, Gi Jeong; Kang, Keon Wook; Chung, June Key; Lee, Dong Soo; Kang, Hyoung Jin; Shin, Hee Young [Seoul National University Hospital, Seoul (Korea, Republic of); Kim, E. Edmund [Seoul National University, Seoul (Korea, Republic of); Rahim, Muhammad Kashif [Nishtar Medical College and Hospital, Multan (Pakistan)

2017-06-15

{sup 18}F-fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging is well known to have clinical significance in the initial staging and response evaluation of the many kinds of neoplasms. However, its role in the pediatric neuroblastoma is not clearly defined. In the present study, the clinical significance of FDG-PET/computed tomography (CT) in 123I- or 131I-metaiodobenzylguanidine (MIBG)-avid pediatric neuroblastoma was investigated. Twenty patients with neuroblastoma who undertook pretreatment FDG PET/CT at our institute between 2008 and 2015 and showed MIBG avidity were retrospectively enrolled in the present study. Clinical information—including histopathology, and serum markers—and several PET parameters—including SUVmax of the primary lesion (Psuv), target-to-background ratio (TBR), metabolic tumor volume (MTV), and coefficient of variation (CV)—were analyzed. The prognostic effect of PET parameters was evaluated in terms of progression-free survival (PFS). Total 20 patients (4.5 ± 3.5 years) were divided as two groups by disease progression. Six patients (30.0 %) experienced disease progression and one patient (5.0 %) died during follow-up period. There were not statistically significant in age, stage, MYCN status, primary tumor size, serum lactate dehydrogenase (LDH), neuron-specific enolase (NSE), and ferritin level between two groups with progression or no progression. However, Psuv (p = 0.017), TBR (p = 0.09), MTV (p = 0.02), and CV (p = 0.036) showed significant differences between two groups. In univariate analysis, PFS was significantly associated with Psuv (p = 0.021) and TBR (p = 0.023). FDG-PET parameters were significantly related with progression of neuroblastoma. FDG-PET/CT may have the potential as a valuable modality for evaluating prognosis in the patients with MIBG-avid pediatric neuroblastoma.

Availability and improvement of a vacuum-type immobilization device in pediatric CT

International Nuclear Information System (INIS)

Tani, Shoji; Mizuno, Naoto; Abe, Syuji

2002-01-01

The essential factors for an immobilization device in pediatric CT are absence of artifacts, safety, no disturbance of the patient's sedation, and ease of handling. We evaluated the suitability of a commercially available vacuum-type immobilization device designed for radiation therapy (Vac-Lok) that meets these requisites. There were no artifacts in scans of the water phantom. The device easily immobilized the patient, was quick to release, and was superior to previous immobilization systems, according to replies to a questionnaire administered to physicians, technologists, and nurses. Schedule delays were reduced by using this device to examine sedated patients (up to 1 year of age). Despite these advantages, the device was too small to immobilize both extremities together when examining older patients. In order to overcome this problem, we invented a special immobilization device for pediatric CT. The new device could be applied to taller patients, up to 85 cm in height (the average height of 2-year-old infants), and was able to contribute to efficient utilization of the examination room. (author)

Comparing Effective Doses During Image-Guided Core Needle Biopsies with Computed Tomography Versus C-Arm Cone Beam CT Using Adult and Pediatric Phantoms.

Science.gov (United States)

Ben-Shlomo, A; Cohen, D; Bruckheimer, E; Bachar, G N; Konstantinovsky, R; Birk, E; Atar, E

2016-05-01

To compare the effective doses of needle biopsies based on dose measurements and simulations using adult and pediatric phantoms, between cone beam c-arm CT (CBCT) and CT. Effective doses were calculated and compared based on measurements and Monte Carlo simulations of CT- and CBCT-guided biopsy procedures of the lungs, liver, and kidney using pediatric and adult phantoms. The effective doses for pediatric and adult phantoms, using our standard protocols for upper, middle and lower lungs, liver, and kidney biopsies, were significantly lower under CBCT guidance than CT. The average effective dose for a 5-year old for these five biopsies was 0.36 ± 0.05 mSv with the standard CBCT exposure protocols and 2.13 ± 0.26 mSv with CT. The adult average effective dose for the five biopsies was 1.63 ± 0.22 mSv with the standard CBCT protocols and 8.22 ± 1.02 mSv using CT. The CT effective dose was higher than CBCT protocols for child and adult phantoms by 803 and 590% for upper lung, 639 and 525% for mid-lung, and 461 and 251% for lower lung, respectively. Similarly, the effective dose was higher by 691 and 762% for liver and 513 and 608% for kidney biopsies. Based on measurements and simulations with pediatric and adult phantoms, radiation effective doses during image-guided needle biopsies of the lung, liver, and kidney are significantly lower with CBCT than with CT.

Developing optimized CT scan protocols: Phantom measurements of image quality

International Nuclear Information System (INIS)

Zarb, Francis; Rainford, Louise; McEntee, Mark F.

2011-01-01

Purpose: The increasing frequency of computerized tomography (CT) examinations is well documented, leading to concern about potential radiation risks for patients. However, the consequences of not performing the CT examination and missing injuries and disease are potentially serious, impacting upon correct patient management. The ALARA principle of dose optimization must be employed for all justified CT examinations. Dose indicators displayed on the CT console as either CT dose index (CTDI) and/or dose length product (DLP), are used to indicate dose and can quantify improvements achieved through optimization. Key scan parameters contributing to dose have been identified in previous literature and in previous work by our group. The aim of this study was to optimize the scan parameters of mA; kV and pitch, whilst maintaining image quality and reducing dose. This research was conducted using psychophysical image quality measurements on a CT quality assurance (QA) phantom establishing the impact of dose optimization on image quality parameters. Method: Current CT scan parameters for head (posterior fossa and cerebrum), abdomen and chest examinations were collected from 57% of CT suites available nationally in Malta (n = 4). Current scan protocols were used to image a Catphan 600 CT QA phantom whereby image quality was assessed. Each scan parameter: mA; kV and pitch were systematically reduced until the contrast resolution (CR), spatial resolution (SR) and noise were significantly lowered. The Catphan 600 images, produced by the range of protocols, were evaluated by 2 expert observers assessing CR, SR and noise. The protocol considered as the optimization threshold was just above the setting that resulted in a significant reduction in CR and noise but not affecting SR at the 95% confidence interval. Results: The limit of optimization threshold was determined for each CT suite. Employing optimized parameters, CTDI and DLP were both significantly reduced (p ≤ 0.001) by

Optimizing radiation exposure for CT localizer radiographs

Energy Technology Data Exchange (ETDEWEB)

Bohrer, Evelyn; Maeder, Ulf; Fiebich, Martin [Univ. of Applied Sciences, Giessen (Germany). Inst. of Medical Physics and Radiation Protection-IMPS; Schaefer, Stefan; Krombach, Gabriele A. [Univ. Hospital Giessen (Germany). Dept. of Radiology; Noel, Peter B. [Technische Univ. Muenchen (Germany). Dept. of Diagnostic and Interventional Radiology

2017-08-01

The trend towards submillisievert CT scans leads to a higher dose fraction of localizer radiographs in CT examinations. The already existing technical capabilities make dose optimization of localizer radiographs worthwhile. Modern CT scanners apply automatic exposure control (AEC) based on attenuation data in such a localizer. Therefore not only this aspect but also the detectability of anatomical landmarks in the localizer for the desired CT scan range adjustment needs to be considered. The effective dose of a head, chest, and abdomen-pelvis localizer radiograph with standard factory settings and user-optimized settings was determined using Monte Carlo simulations. CT examinations of an anthropomorphic phantom were performed using multiple sets of acquisition parameters for the localizer radiograph and the AEC for the subsequent helical CT scan. Anatomical landmarks were defined to assess the image quality of the localizer. CTDI{sub vol} and effective mAs per slice of the helical CT scan were recorded to examine the impact of localizer settings on a helical CT scan. The dose of the localizer radiograph could be decreased by more than 90% while the image quality remained sufficient when selecting the lowest available settings (80 kVp, 20 mA, pa tube position). The tube position during localizer acquisition had a greater impact on the AEC than the reduction of tube voltage and tube current. Except for the use of a pa tube position, all changes of acquisition parameters for the localizer resulted in a decreased total radiation exposure. A dose reduction of CT localizer radiograph is necessary and possible. In the examined CT system there was no negative impact on the modulated helical CT scan when the lowest tube voltage and tube current were used for the localizer.

Automatic CT simulation optimization for radiation therapy: A general strategy

Energy Technology Data Exchange (ETDEWEB)

Li, Hua, E-mail: huli@radonc.wustl.edu; Chen, Hsin-Chen; Tan, Jun; Gay, Hiram; Michalski, Jeff M.; Mutic, Sasa [Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States); Yu, Lifeng [Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States); Anastasio, Mark A. [Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63110 (United States); Low, Daniel A. [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California 90095 (United States)

2014-03-15

Purpose: In radiation therapy, x-ray computed tomography (CT) simulation protocol specifications should be driven by the treatment planning requirements in lieu of duplicating diagnostic CT screening protocols. The purpose of this study was to develop a general strategy that allows for automatically, prospectively, and objectively determining the optimal patient-specific CT simulation protocols based on radiation-therapy goals, namely, maintenance of contouring quality and integrity while minimizing patient CT simulation dose. Methods: The authors proposed a general prediction strategy that provides automatic optimal CT simulation protocol selection as a function of patient size and treatment planning task. The optimal protocol is the one that delivers the minimum dose required to provide a CT simulation scan that yields accurate contours. Accurate treatment plans depend on accurate contours in order to conform the dose to actual tumor and normal organ positions. An image quality index, defined to characterize how simulation scan quality affects contour delineation, was developed and used to benchmark the contouring accuracy and treatment plan quality within the predication strategy. A clinical workflow was developed to select the optimal CT simulation protocols incorporating patient size, target delineation, and radiation dose efficiency. An experimental study using an anthropomorphic pelvis phantom with added-bolus layers was used to demonstrate how the proposed prediction strategy could be implemented and how the optimal CT simulation protocols could be selected for prostate cancer patients based on patient size and treatment planning task. Clinical IMRT prostate treatment plans for seven CT scans with varied image quality indices were separately optimized and compared to verify the trace of target and organ dosimetry coverage. Results: Based on the phantom study, the optimal image quality index for accurate manual prostate contouring was 4.4. The optimal tube

Automatic CT simulation optimization for radiation therapy: A general strategy.

Science.gov (United States)

Li, Hua; Yu, Lifeng; Anastasio, Mark A; Chen, Hsin-Chen; Tan, Jun; Gay, Hiram; Michalski, Jeff M; Low, Daniel A; Mutic, Sasa

2014-03-01

In radiation therapy, x-ray computed tomography (CT) simulation protocol specifications should be driven by the treatment planning requirements in lieu of duplicating diagnostic CT screening protocols. The purpose of this study was to develop a general strategy that allows for automatically, prospectively, and objectively determining the optimal patient-specific CT simulation protocols based on radiation-therapy goals, namely, maintenance of contouring quality and integrity while minimizing patient CT simulation dose. The authors proposed a general prediction strategy that provides automatic optimal CT simulation protocol selection as a function of patient size and treatment planning task. The optimal protocol is the one that delivers the minimum dose required to provide a CT simulation scan that yields accurate contours. Accurate treatment plans depend on accurate contours in order to conform the dose to actual tumor and normal organ positions. An image quality index, defined to characterize how simulation scan quality affects contour delineation, was developed and used to benchmark the contouring accuracy and treatment plan quality within the predication strategy. A clinical workflow was developed to select the optimal CT simulation protocols incorporating patient size, target delineation, and radiation dose efficiency. An experimental study using an anthropomorphic pelvis phantom with added-bolus layers was used to demonstrate how the proposed prediction strategy could be implemented and how the optimal CT simulation protocols could be selected for prostate cancer patients based on patient size and treatment planning task. Clinical IMRT prostate treatment plans for seven CT scans with varied image quality indices were separately optimized and compared to verify the trace of target and organ dosimetry coverage. Based on the phantom study, the optimal image quality index for accurate manual prostate contouring was 4.4. The optimal tube potentials for patient sizes

Optimization of Protocol CT, PET-CT, whole body; Optimizacion de protocolo CT, en PET-CT, de cuerpo entero

Energy Technology Data Exchange (ETDEWEB)

Gutierrez, Fredys Santos, E-mail: fsantos@ccss.sa.cr [Caja Costarricense de Seguro Social (ACCPR/CCSS), San Jose (Costa Rica). Area Control de Calidade Y Proteccion Radiologica; Namias, Mauro, E-mail: mnamias@gmail.com [Comision Nacional de Energia Atomica (FCDN/CNEA), Buenos Aires (Argentina). Fundacion Centro Diagnostico Nuclear

2013-11-01

The objective of this study was to optimize the acquisition protocols and processing existing of the CT PET/CT scanner for clinical use of Nuclear Diagnostic Center Foundation, a way to minimize the radiation dose while maintaining diagnostic image quality properly. Dosimetric data of PET / CT service were surveyed and obtained the baseline against which we compare and define strategies and modifications to develop online. We selected transaxial up to the pulmonary hilum and liver slices as the anatomical regions of interest that led to the standardization of the study.

Development of low-dose protocols for thin-section CT assessment of cystic fibrosis in pediatric patients.

LENUS (Irish Health Repository)

O'Connor, Owen J

2010-12-01

To develop low-dose thin-section computed tomographic (CT) protocols for assessment of cystic fibrosis (CF) in pediatric patients and determine the clinical usefulness thereof compared with chest radiography.

Image Registration for PET/CT and CT Images with Particle Swarm Optimization

International Nuclear Information System (INIS)

Lee, Hak Jae; Kim, Yong Kwon; Lee, Ki Sung; Choi, Jong Hak; Kim, Chang Kyun; Moon, Guk Hyun; Joo, Sung Kwan; Kim, Kyeong Min; Cheon, Gi Jeong

2009-01-01

Image registration is a fundamental task in image processing used to match two or more images. It gives new information to the radiologists by matching images from different modalities. The objective of this study is to develop 2D image registration algorithm for PET/CT and CT images acquired by different systems at different times. We matched two CT images first (one from standalone CT and the other from PET/CT) that contain affluent anatomical information. Then, we geometrically transformed PET image according to the results of transformation parameters calculated by the previous step. We have used Affine transform to match the target and reference images. For the similarity measure, mutual information was explored. Use of particle swarm algorithm optimized the performance by finding the best matched parameter set within a reasonable amount of time. The results show good agreements of the images between PET/CT and CT. We expect the proposed algorithm can be used not only for PET/CT and CT image registration but also for different multi-modality imaging systems such as SPECT/CT, MRI/PET and so on.

Operational modeling of dose and noise for computed tomography in a pediatric hospital

International Nuclear Information System (INIS)

Miller Clemente, Rafael A.; Perez Diaz, Marlen; Mora Reyes, Yudel; Rodriguez Garlobo, Maikel; Castillo Salazar, Rafael

2008-01-01

Noise becomes a critical factor in Computed Tomography (CT) because most detailed applications on soft tissue show a low contrast nature. Noise establishes an inferior limit to the contrast detectable by the observer. Various pixel noise models had been devised taking into account operational parameters on Single and Multi Detector Slice CT. The aim of this work was to obtain a predictive operational model for image noise addressed to pediatric protocols, taking into account scanning factors with a Single Slice CT unit dedicated to pediatric applications. A multiple linear regression model is proposed to predict noise in images of uniform phantoms equivalent to head and abdomen. A model for reported volumetric Computed Tomography Dose Index (CTDI VOL ) was obtained too for tradeoffs analysis approaching optimization purposes in pediatric applications. Eight independent variables were considered: phantom diameter, reconstruction mode, tube current, tube kVp, collimation, Field of View (FOV), reconstruction filter, and post processing filter. Results show good agreement with measurements, with adjusted coefficients of multiple determination of 0.936 and 0.744 for noise and CTDI VOL models respectively. Tube current, object diameter, collimation and reconstruction filters were the most influencing variables. The model application contributes to identify each factor's influence enhancing the operational possibilities approaching optimization of noise and dose tradeoffs. Acceptable noise levels and optimization strategies can be devised from models obtained towards lower tube current values combined with greater slice thickness and kVp taking into account the doses to pediatric patients. (author)

Analysis of clinical value of CT in the diagnosis of pediatric pneumonia and mycoplasma pneumonia

OpenAIRE

GONG, LIANG; ZHANG, CHONG-LIN; ZHEN, QING

2016-01-01

Pneumonia is an infectious disease of the lung causing mortality. Mycoplasma pneumonia (MP) is an atypical bacterial pneumonia that damages several organs. Lung computed tomography (CT) has been utilized in its identification. The aim of the present study was to examine the value of computed tomography diagnosis for pediatric MP. The present study prospectively analyzed the clinical and imaging data of 1,280 cases of pediatric MP in the out- and inpatient departments from March, 2010 to March...

The development of a population of 4D pediatric XCAT phantoms for imaging research and optimization

Energy Technology Data Exchange (ETDEWEB)

Segars, W. P., E-mail: paul.segars@duke.edu; Norris, Hannah; Sturgeon, Gregory M.; Zhang, Yakun; Bond, Jason; Samei, E. [Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Minhas, Anum; Frush, D. [Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Tward, Daniel J.; Ratnanather, J. T.; Miller, M. I. [Center for Imaging Science, Johns Hopkins University, Baltimore, Maryland 21218 (United States)

2015-08-15

Purpose: We previously developed a set of highly detailed 4D reference pediatric extended cardiac-torso (XCAT) phantoms at ages of newborn, 1, 5, 10, and 15 yr with organ and tissue masses matched to ICRP Publication 89 values. In this work, we extended this reference set to a series of 64 pediatric phantoms of varying age and height and body mass percentiles representative of the public at large. The models will provide a library of pediatric phantoms for optimizing pediatric imaging protocols. Methods: High resolution positron emission tomography-computed tomography data obtained from the Duke University database were reviewed by a practicing experienced radiologist for anatomic regularity. The CT portion of the data was then segmented with manual and semiautomatic methods to form a target model defined using nonuniform rational B-spline surfaces. A multichannel large deformation diffeomorphic metric mapping algorithm was used to calculate the transform from the best age matching pediatric XCAT reference phantom to the patient target. The transform was used to complete the target, filling in the nonsegmented structures and defining models for the cardiac and respiratory motions. The complete phantoms, consisting of thousands of structures, were then manually inspected for anatomical accuracy. The mass for each major tissue was calculated and compared to linearly interpolated ICRP values for different ages. Results: Sixty four new pediatric phantoms were created in this manner. Each model contains the same level of detail as the original XCAT reference phantoms and also includes parameterized models for the cardiac and respiratory motions. For the phantoms that were 10 yr old and younger, we included both sets of reproductive organs. This gave them the capability to simulate both male and female anatomy. With this, the population can be expanded to 92. Wide anatomical variation was clearly seen amongst the phantom models, both in organ shape and size, even for

Determination of dosimetric quantities in pediatric abdominal computed tomography scans

Energy Technology Data Exchange (ETDEWEB)

Jornada, Tiago da Silva [Universidade Federal de Sao Paulo (UNIFESP), Sao Paulo, SP (Brazil). Escola Paulista de Medicina. Dept. de Diagnostipo por Imagem; Silva, Teogenes Augusto da, E-mail: silvata@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2014-09-15

Objective: aiming at contributing to the knowledge on doses in computed tomography (CT), this study has the objective of determining dosimetric quantities associated with pediatric abdominal CT scans, comparing the data with diagnostic reference levels (DRL). Materials and methods: the study was developed with a Toshiba Asteion single-slice CT scanner and a GE BrightSpeed multi-slice CT unit in two hospitals. Measurements were performed with a pencil-type ionization chamber and a 16 cm-diameter polymethylmethacrylate trunk phantom. Results: No significant difference was observed in the values for weighted air kerma index (C{sub W}), but the differences were relevant in values for volumetric air kerma index (C{sub VOL}), air kerma-length product (P{sub KL,CT}) and effective dose. Conclusion: Only the CW values were lower than the DRL, suggesting that dose optimization might not be necessary. However, P{sub KL,CT} and effective dose values stressed that there still is room for reducing pediatric radiation doses. The present study emphasizes the importance of determining all dosimetric quantities associated with CT scans. (author)

Determination of dosimetric quantities in pediatric abdominal computed tomography scans*

Science.gov (United States)

Jornada, Tiago da Silva; da Silva, Teógenes Augusto

2014-01-01

Objective Aiming at contributing to the knowledge on doses in computed tomography (CT), this study has the objective of determining dosimetric quantities associated with pediatric abdominal CT scans, comparing the data with diagnostic reference levels (DRL). Materials and methods The study was developed with a Toshiba Asteion single-slice CT scanner and a GE BrightSpeed multi-slice CT unit in two hospitals. Measurements were performed with a pencil-type ionization chamber and a 16 cm-diameter polymethylmethacrylate trunk phantom. Results No significant difference was observed in the values for weighted air kerma index (CW), but the differences were relevant in values for volumetric air kerma index (CVOL), air kerma-length product (PKL,CT) and effective dose. Conclusion Only the CW values were lower than the DRL, suggesting that dose optimization might not be necessary. However, PKL,CT and effective dose values stressed that there still is room for reducing pediatric radiation doses. The present study emphasizes the importance of determining all dosimetric quantities associated with CT scans. PMID:25741103

Construction of pediatric homogeneous phantoms for optimization of chest and skull radiographs

Energy Technology Data Exchange (ETDEWEB)

Alves, Allan Felipe Fattori, E-mail: allan@ibb.unesp.br [Instituto de Biociências de Botucatu, P.O. BOX 510, Departamento de Física e Biofísica, UNESP—Universidade Estadual Paulista, Distrito de Rubião Junior S/N, Botucatu, 18618-000 São Paulo (Brazil); Miranda, José Ricardo de Arruda, E-mail: jmiranda@ibb.unesp.br [Instituto de Biociências de Botucatu, Departamento de Física e Biofísica, UNESP—Universidade Estadual Paulista, Distrito de Rubião Junior S/N, Botucatu, 18618-000 São Paulo (Brazil); Bacchim Neto, Fernando Antonio, E-mail: fernando.bacchim@gmail.com [Instituto de Biociências de Botucatu, Departamento de Física e Biofísica, UNESP—Universidade Estadual Paulista, Distrito de Rubião Junior S/N, Botucatu, 18618-000 São Paulo (Brazil); Duarte, Sérgio Barbosa, E-mail: sbd@cbpf.br [Centro Brasileiro de Pesquisas Físicas, Laboratório de Altas Energias, Dr. Xavier Sigaud, 150, Rio de Janeiro, 22290-180 Rio de Janeiro (Brazil); Pina, Diana Rodrigues de, E-mail: drpina@fmb.unesp.br [Departamento de Doenças Tropicais e Diagnóstico por Imagem, Faculdade de Medicina de Botucatu, UNESP—Universidade Estadual Paulista, Distrito de Rubião Junior S/N, Botucatu, 18618-000 São Paulo (Brazil)

2015-08-15

Highlights: • We developed two pediatric patient-equivalent phantoms. • Our phantoms were used in the optimization process of computed radiography systems. • We evaluated physical quantities such as effective detective quantum efficiency and contrast-to-noise ratio. • We determined optimized techniques for pediatric protocols. - Abstract: Objectives: To develop two pediatric patient-equivalent phantoms, the Pediatric Chest Equivalent Patient (PCEP) and the Pediatric Skull Equivalent Patient (PSEP) for children aged 1 to 5 years. We also used both phantoms for image quality evaluations in computed radiography systems to determine Gold Standard (GS) techniques for pediatric patients. Methods: To determine the simulator materials thickness (Lucite and aluminum), we quantified biological tissues (lung, soft, and bone) using an automatic computational algorithm. To objectively establish image quality levels, two physical quantities were used: effective detective quantum efficiency and contrast-to-noise ratio. These quantities were associated to values obtained for standard patients from previous studies. Results: For chest radiographies, the GS technique applied was 81 kVp, associated to 2.0 mAs and 83.6 μGy of entrance skin dose (ESD), while for skull radiographies, the GS technique was 70 kVp, associated to 5 mAs and 339 μGy of ESD. Conclusion: This procedure allowed us to choose optimized techniques for pediatric protocols, thus improving quality of diagnosis for pediatric population and reducing diagnostic costs to our institution. These results could also be easily applied to other services with different equipment technologies.

Anticlockwise swirl of mesenteric vessels: A normal CT appearance, retrospective analysis of 200 pediatric patients

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Sodhi, Kushaljit S., E-mail: sodhiks@gmail.com [Department of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Bhatia, Anmol, E-mail: anmol_bhatia26@yahoo.co.in [Department of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Saxena, Akshay K., E-mail: fatakshay@yahoo.com [Department of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Rao, Katragadda L.N., E-mail: klnrao@hotmail.com [Department of Pediatric Surgery, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Menon, Prema, E-mail: menonprema@hotmail.com [Department of Pediatric Surgery, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Khandelwal, Niranjan, E-mail: khandelwaln@hotmail.com [Department of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India)

2014-04-15

Objective: The counterclockwise rotation of the SMV on SMA is a normal and non-specific finding, which results in an incomplete swirl formation on CT scans. However, it has a potential to be misinterpreted as ‘midgut volvulus’ resulting in serious clinical implications. The study was done to determine the frequency and degree of counterclockwise rotation of the SMV on SMA on CT in normal otherwise asymptomatic pediatric patients undergoing CT scan. Methods: In this IRB approved study, we retrospectively analyzed abdominal CT scan examinations of 200 consecutive pediatric patients (age range of 11 days to 18 years), which were performed for different clinical indications over a period of 10 months. They were evaluated for the absence or presence and degree of counterclockwise rotation of the mesenteric vessels. Results: Of the 200 patients, 128 (64%) patients showed no clockwise or anticlockwise rotation of mesenteric vessels. Counterclockwise rotation of SMV on SMA was seen in 72 (36%) patients. Further, the degree of rotation of vessels was also calculated, based on the criteria proposed by the authors. Conclusions: The counterclockwise rotation of SMV on SMA gives an appearance of mesenteric whirlpool in otherwise normal mesenteric vessels and can be misinterpreted as midgut volvulus. It is a normal CT appearance and is due to a variation in branching pattern of mesenteric vessels. Awareness of this normal branching pattern of mesenteric vessels is important to avoid an inadvertent laparotomy.

Anticlockwise swirl of mesenteric vessels: A normal CT appearance, retrospective analysis of 200 pediatric patients

International Nuclear Information System (INIS)

Sodhi, Kushaljit S.; Bhatia, Anmol; Saxena, Akshay K.; Rao, Katragadda L.N.; Menon, Prema; Khandelwal, Niranjan

2014-01-01

Objective: The counterclockwise rotation of the SMV on SMA is a normal and non-specific finding, which results in an incomplete swirl formation on CT scans. However, it has a potential to be misinterpreted as ‘midgut volvulus’ resulting in serious clinical implications. The study was done to determine the frequency and degree of counterclockwise rotation of the SMV on SMA on CT in normal otherwise asymptomatic pediatric patients undergoing CT scan. Methods: In this IRB approved study, we retrospectively analyzed abdominal CT scan examinations of 200 consecutive pediatric patients (age range of 11 days to 18 years), which were performed for different clinical indications over a period of 10 months. They were evaluated for the absence or presence and degree of counterclockwise rotation of the mesenteric vessels. Results: Of the 200 patients, 128 (64%) patients showed no clockwise or anticlockwise rotation of mesenteric vessels. Counterclockwise rotation of SMV on SMA was seen in 72 (36%) patients. Further, the degree of rotation of vessels was also calculated, based on the criteria proposed by the authors. Conclusions: The counterclockwise rotation of SMV on SMA gives an appearance of mesenteric whirlpool in otherwise normal mesenteric vessels and can be misinterpreted as midgut volvulus. It is a normal CT appearance and is due to a variation in branching pattern of mesenteric vessels. Awareness of this normal branching pattern of mesenteric vessels is important to avoid an inadvertent laparotomy

Effects of adaptive statistical iterative reconstruction on radiation dose reduction and diagnostic accuracy of pediatric abdominal CT

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Bae, Sohi; Kim, Myung-Joon; Lee, Mi-Jung [Yonsei University College of Medicine, Department of Radiology and Research Institute of Radiological Science, Severance Children' s Hospital, Seoul (Korea, Republic of); Yoon, Choon-Sik [Yonsei University College of Medicine, Department of Radiology, Gangnam Severance Hospital, Seoul (Korea, Republic of); Kim, Dong Wook; Hong, Jung Hwa [Yonsei University College of Medicine, Biostatistics Collaboration Unit, Seoul (Korea, Republic of)

2014-12-15

Since children are more radio-sensitive than adults, there is a need to minimize radiation exposure during CT exams. To evaluate the effects of adaptive statistical iterative reconstruction (ASIR) on radiation dose reduction, image quality and diagnostic accuracy in pediatric abdominal CT. We retrospectively reviewed the abdominal CT examinations of 41 children (24 boys and 17 girls; mean age: 10 years) with a low-dose radiation protocol and reconstructed with ASIR (the ASIR group). We also reviewed routine-dose abdominal CT examinations of 41 age- and sex-matched controls reconstructed with filtered-back projection (control group). Image quality was assessed objectively as noise measured in the liver, spleen and aorta, as well as subjectively by three pediatric radiologists for diagnostic acceptability using a four-point scale. Radiation dose and objective image qualities of each group were compared with the paired t-test. Diagnostic accuracy was evaluated by reviewing follow-up imaging studies and medical records in 2012 and 2013. There was 46.3% dose reduction of size-specific dose estimates in ASIR group (from 13.4 to 7.2 mGy) compared with the control group. Objective noise was higher in the liver, spleen and aorta of the ASIR group (P < 0.001). However, the subjective image quality was average or superior in 84-100% of studies. Only one image was subjectively rated as unacceptable by one reviewer. There was only one case with interpretational error in the control group and none in the ASIR group. Use of the ASIR technique resulted in greater than a 45% reduction in radiation dose without impairing subjective image quality or diagnostic accuracy in pediatric abdominal CT, despite increased objective image noise. (orig.)

Effects of adaptive statistical iterative reconstruction on radiation dose reduction and diagnostic accuracy of pediatric abdominal CT

International Nuclear Information System (INIS)

Bae, Sohi; Kim, Myung-Joon; Lee, Mi-Jung; Yoon, Choon-Sik; Kim, Dong Wook; Hong, Jung Hwa

2014-01-01

Since children are more radio-sensitive than adults, there is a need to minimize radiation exposure during CT exams. To evaluate the effects of adaptive statistical iterative reconstruction (ASIR) on radiation dose reduction, image quality and diagnostic accuracy in pediatric abdominal CT. We retrospectively reviewed the abdominal CT examinations of 41 children (24 boys and 17 girls; mean age: 10 years) with a low-dose radiation protocol and reconstructed with ASIR (the ASIR group). We also reviewed routine-dose abdominal CT examinations of 41 age- and sex-matched controls reconstructed with filtered-back projection (control group). Image quality was assessed objectively as noise measured in the liver, spleen and aorta, as well as subjectively by three pediatric radiologists for diagnostic acceptability using a four-point scale. Radiation dose and objective image qualities of each group were compared with the paired t-test. Diagnostic accuracy was evaluated by reviewing follow-up imaging studies and medical records in 2012 and 2013. There was 46.3% dose reduction of size-specific dose estimates in ASIR group (from 13.4 to 7.2 mGy) compared with the control group. Objective noise was higher in the liver, spleen and aorta of the ASIR group (P < 0.001). However, the subjective image quality was average or superior in 84-100% of studies. Only one image was subjectively rated as unacceptable by one reviewer. There was only one case with interpretational error in the control group and none in the ASIR group. Use of the ASIR technique resulted in greater than a 45% reduction in radiation dose without impairing subjective image quality or diagnostic accuracy in pediatric abdominal CT, despite increased objective image noise. (orig.)

Application- and patient size-dependent optimization of x-ray spectra for CT

International Nuclear Information System (INIS)

Kalender, Willi A.; Deak, Paul; Kellermeier, Markus; Straten, Marcel van; Vollmar, Sabrina V.

2009-01-01

V were found as adequate choices with optimal values increasing for larger cross sections, e.g., for large abdomens voltages higher than 140 kV may be indicated. For bone and iodine imaging the optimum values were generally found at significantly lower voltages of typically below 80 kV. This offers a potential for dose reduction of up to 50%, but demands significantly higher power values in most cases. The authors concluded that voltage settings in CT should be varied more often than is common in practice today and should be chosen not only according to patient size but also according to the substance imaged in order to minimize dose while not compromising image quality. A reduction from 120 to 80 kV, for example, would yield a reduction in patient dose by more than half for coronary CT angiography. The use of lower voltages has to be recommended for contrast medium studies in cardiac and pediatric CT.

Ultra-high pitch chest computed tomography at 70 kVp tube voltage in an anthropomorphic pediatric phantom and non-sedated pediatric patients. Initial experience with 3{sup rd} generation dual-source CT

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Hagelstein, Claudia; Henzler, Thomas; Haubenreisser, Holger; Meyer, Mathias; Sudarski, Sonja; Schoenberg, Stefan O.; Neff, K. Wolfgang; Weis, Meike [Univ. Medical Center Mannheim (Germany). Inst. of Clinical Radiology and Nuclear Medicine

2016-07-01

Minimizing radiation dose while at the same time preserving image quality is of particular importance in pediatric chest CT. Very recently, CT imaging with a tube voltage of 70 kVp has become clinically available. However, image noise is inversely proportional to the tube voltage. We aimed to investigate radiation dose and image quality of pediatric chest CT performed at 70 kVp in an anthropomorphic pediatric phantom as well as in clinical patients. An anthropomorphic pediatric phantom, which resembles a one-year-old child in physiognomy, was scanned on the 3{sup rd} generation dual-source CT (DSCT) system at 70 kVp and 80 kVp and a fixed ultra low tube-current of 8 mAs to solely evaluate the impact of lowering tube voltage. After the phantom measurements, 18 pediatric patients (mean 29.5 months; range 1-91 months; 21 examinations) underwent 3.2 high-pitch chest CT on the same DSCT system at 70 kVp tube voltage without any sedation. Radiation dose and presence of motion artifacts was compared to a retrospectively identified patient cohort examined at 80 kVp on a 16-slice single-source-CT (SSCT; n = 15; 14/15 with sedation; mean 30.7 months; range 0-96 months; pitch = 1.5) or on a 2{sup nd} generation DSCT without any sedation (n = 6; mean 32.8 months; range 4-61 months; pitch = 3.2). Radiation dose in the phantom scans was reduced by approximately 40% when using a tube voltage of 70 kVp instead of 80 kVp. In the pediatric patient group examined at 70 kVp age-specific effective dose (ED; mean 0.5 ± 0.2 mSv) was significantly lower when compared to the retrospective cohort scanned at 80 kVp on the 16-slice-SSCT (mean ED: 1.0 ± 0.3 mSv; p < 0.0001) and also considerably lower when compared to the cohort scanned at 80 kVp on the 2{sup nd} generation DSCT (mean ED: 0.9 ± 0.5 mSv). None of the prospective, sedation-free CT examinations showed any motion artifacts whereas 13/15 examinations of the retrospective patient cohort scanned at 80 kVp with a pitch of 1

Comparing Effective Doses During Image-Guided Core Needle Biopsies with Computed Tomography Versus C-Arm Cone Beam CT Using Adult and Pediatric Phantoms

International Nuclear Information System (INIS)

Ben-Shlomo, A.; Cohen, D.; Bruckheimer, E.; Bachar, G. N.; Konstantinovsky, R.; Birk, E.; Atar, E.

2016-01-01

PurposeTo compare the effective doses of needle biopsies based on dose measurements and simulations using adult and pediatric phantoms, between cone beam c-arm CT (CBCT) and CT.MethodEffective doses were calculated and compared based on measurements and Monte Carlo simulations of CT- and CBCT-guided biopsy procedures of the lungs, liver, and kidney using pediatric and adult phantoms.ResultsThe effective doses for pediatric and adult phantoms, using our standard protocols for upper, middle and lower lungs, liver, and kidney biopsies, were significantly lower under CBCT guidance than CT. The average effective dose for a 5-year old for these five biopsies was 0.36 ± 0.05 mSv with the standard CBCT exposure protocols and 2.13 ± 0.26 mSv with CT. The adult average effective dose for the five biopsies was 1.63 ± 0.22 mSv with the standard CBCT protocols and 8.22 ± 1.02 mSv using CT. The CT effective dose was higher than CBCT protocols for child and adult phantoms by 803 and 590 % for upper lung, 639 and 525 % for mid-lung, and 461 and 251 % for lower lung, respectively. Similarly, the effective dose was higher by 691 and 762 % for liver and 513 and 608 % for kidney biopsies.ConclusionsBased on measurements and simulations with pediatric and adult phantoms, radiation effective doses during image-guided needle biopsies of the lung, liver, and kidney are significantly lower with CBCT than with CT.

Comparing Effective Doses During Image-Guided Core Needle Biopsies with Computed Tomography Versus C-Arm Cone Beam CT Using Adult and Pediatric Phantoms

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Ben-Shlomo, A. [Soreq NRC, Radiation Protection Domain (Israel); Cohen, D.; Bruckheimer, E. [Schneider Children’s Medical Center, Section of Pediatric Cardiology (Israel); Bachar, G. N.; Konstantinovsky, R. [Rabin Medical Center, Department of Diagnostic Radiology (Israel); Birk, E. [Schneider Children’s Medical Center, Section of Pediatric Cardiology (Israel); Atar, E., E-mail: elia@clalit.org.il [Rabin Medical Center, Department of Diagnostic Radiology (Israel)

2016-05-15

PurposeTo compare the effective doses of needle biopsies based on dose measurements and simulations using adult and pediatric phantoms, between cone beam c-arm CT (CBCT) and CT.MethodEffective doses were calculated and compared based on measurements and Monte Carlo simulations of CT- and CBCT-guided biopsy procedures of the lungs, liver, and kidney using pediatric and adult phantoms.ResultsThe effective doses for pediatric and adult phantoms, using our standard protocols for upper, middle and lower lungs, liver, and kidney biopsies, were significantly lower under CBCT guidance than CT. The average effective dose for a 5-year old for these five biopsies was 0.36 ± 0.05 mSv with the standard CBCT exposure protocols and 2.13 ± 0.26 mSv with CT. The adult average effective dose for the five biopsies was 1.63 ± 0.22 mSv with the standard CBCT protocols and 8.22 ± 1.02 mSv using CT. The CT effective dose was higher than CBCT protocols for child and adult phantoms by 803 and 590 % for upper lung, 639 and 525 % for mid-lung, and 461 and 251 % for lower lung, respectively. Similarly, the effective dose was higher by 691 and 762 % for liver and 513 and 608 % for kidney biopsies.ConclusionsBased on measurements and simulations with pediatric and adult phantoms, radiation effective doses during image-guided needle biopsies of the lung, liver, and kidney are significantly lower with CBCT than with CT.

Adapting protocols of CT imaging in a pediatric emergency department. Evaluation of image quality and dose; Adaptacion de los protocolos de adquisicion de imagenes de TC pediatricos en un servicio de urgencia. Valoracion de la calidad de imagen y dosis

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Batista Arce, A.; Gonzalez Lopez, S.; Catalan Acosta, A.; Casares Magaz, O.; Hernandez Armas, O.; Hernandez Armas, J.

2011-07-01

The purpose of this study was to assess qualitatively the picture quality in relation to the radiation dose delivered in CT studies of computer tomograph Pediatric Emergency Department of Hospital Universitario de Canarias (HUC) in order to optimize the technical parameters used these radiological examinations so as to obtain optimal image quality at the lowest possible dose.

Evaluation of radiation dose in pediatric head CT examination: a phantom study

Science.gov (United States)

Norhasrina Nik Din, Nik; Zainon, Rafidah; Rahman, Ahmad Taufek Abdul

2018-01-01

The aim of this study was to evaluate the radiation dose in pediatric head Computed Tomography examination. It was reported that decreasing tube voltage in CT examination can reduce the dose to patients significantly. A head phantom was scanned with dual-energy CT at 80 kV and 120 kV. The tube current was set using automatic exposure control mode and manual setting. The pitch was adjusted to 1.4, 1.45 and 1.5 while the slice thickness was set at 5 mm. The dose was measured based on CT Dose Index (CTDI). Results from this study have shown that the image noise increases substantially with low tube voltage. The average dose was 2.60 mGy at CT imaging parameters of 80 kV and 10 - 30 mAs. The dose increases up to 17.19 mGy when the CT tube voltage increases to 120 kV. With the reduction of tube voltage from 120 kV to 80 kV, the radiation dose can be reduced by 12.1% to 15.1% without degradation of contrast-to-noise ratio.

Computed Tomography (CT) -- Head

Medline Plus

Full Text Available ... full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams Blood Clots CT Perfusion of the Head CT Angiography ( ...

Early Head CT Findings Are Associated With Outcomes After Pediatric Out-of-Hospital Cardiac Arrest.

Science.gov (United States)

Starling, Rebecca M; Shekdar, Karuna; Licht, Dan; Nadkarni, Vinay M; Berg, Robert A; Topjian, Alexis A

2015-07-01

Head CT after out-of-hospital cardiac arrest is often obtained to evaluate intracranial pathology. Among children admitted to the PICU following pediatric out-of-hospital cardiac arrest, we hypothesized that loss of gray-white matter differentiation and basilar cistern and sulcal effacement are associated with mortality and unfavorable neurologic outcome. Retrospective, cohort study. Single, tertiary-care center PICU. Seventy-eight patients less than 18 years old who survived out-of-hospital cardiac arrest to PICU admission and had a head CT within 24 hours of return of spontaneous circulation were evaluated from July 2005 through May 2012. None. Median time to head CT from return of spontaneous circulation was 3.3 hours (1.0, 6.0). Median patient age was 2.3 years (0.4, 9.5). Thirty-nine patients (50%) survived, of whom 29 (74%) had favorable neurologic outcome. Nonsurvivors were more likely than survivors to have 1) loss of gray-white matter differentiation (Hounsfield unit ratios, 0.96 [0.88, 1.07] vs 1.1 [1.07, 1.2]; p pediatric out-of-hospital cardiac arrest. Select patients may have favorable outcomes despite these findings.

Inter-radiologist agreement for CT scoring of pediatric splenic injuries and effect on an established clinical practice guideline.

Science.gov (United States)

Leschied, Jessica R; Mazza, Michael B; Davenport, Matthew; Chong, Suzanne T; Smith, Ethan A; Hoff, Carrie N; Ladino-Torres, Maria F; Khalatbari, Shokoufeh; Ehrlich, Peter F; Dillman, Jonathan R

2016-02-01

The American Pediatric Surgical Association (APSA) advocates for the use of a clinical practice guideline to direct management of hemodynamically stable pediatric spleen injuries. The clinical practice guideline is based on the CT score of the spleen injury according to the American Association for the Surgery of Trauma (AAST) CT scoring system. To determine the potential effect of radiologist agreement for CT scoring of pediatric spleen injuries on an established APSA clinical practice guideline. We retrospectively analyzed blunt splenic injuries occurring in children from January 2007 to January 2012 at a single level 1 trauma center (n = 90). Abdominal CT exams performed at clinical presentation were reviewed by four radiologists who documented the following: (1) splenic injury grade (AAST system), (2) arterial extravasation and (3) pseudoaneurysm. Inter-rater agreement for AAST injury grade was assessed using the multi-rater Fleiss kappa and Kendall coefficient of concordance. Inter-rater agreement was assessed using weighted (AAST injury grade) or prevalence-adjusted bias-adjusted (binary measures) kappa statistics; 95% confidence intervals were calculated. We evaluated the hypothetical effect of radiologist disagreement on an established APSA clinical practice guideline. Inter-rater agreement was good for absolute AAST injury grade (kappa: 0.64 [0.59–0.69]) and excellent for relative AAST injury grade (Kendall w: 0.90). All radiologists agreed on the AAST grade in 52% of cases. Based on an established clinical practice guideline, radiologist disagreement could have changed the decision for intensive care management in 11% (10/90) of children, changed the length of hospital stay in 44% (40/90), and changed the time to return to normal activity in 44% (40/90). Radiologist agreement when assigning splenic AAST injury grades is less than perfect, and disagreements have the potential to change management in a substantial number of pediatric patients.

Inter-radiologist agreement for CT scoring of pediatric splenic injuries and effect on an established clinical practice guideline

International Nuclear Information System (INIS)

Leschied, Jessica R.; Smith, Ethan A.; Ladino-Torres, Maria F.; Dillman, Jonathan R.; Mazza, Michael B.; Chong, Suzanne T.; Hoff, Carrie N.; Davenport, Matthew S.; Khalatbari, Shokoufeh; Ehrlich, Peter F.

2016-01-01

The American Pediatric Surgical Association (APSA) advocates for the use of a clinical practice guideline to direct management of hemodynamically stable pediatric spleen injuries. The clinical practice guideline is based on the CT score of the spleen injury according to the American Association for the Surgery of Trauma (AAST) CT scoring system. To determine the potential effect of radiologist agreement for CT scoring of pediatric spleen injuries on an established APSA clinical practice guideline. We retrospectively analyzed blunt splenic injuries occurring in children from January 2007 to January 2012 at a single level 1 trauma center (n = 90). Abdominal CT exams performed at clinical presentation were reviewed by four radiologists who documented the following: (1) splenic injury grade (AAST system), (2) arterial extravasation and (3) pseudoaneurysm. Inter-rater agreement for AAST injury grade was assessed using the multi-rater Fleiss kappa and Kendall coefficient of concordance. Inter-rater agreement was assessed using weighted (AAST injury grade) or prevalence-adjusted bias-adjusted (binary measures) kappa statistics; 95% confidence intervals were calculated. We evaluated the hypothetical effect of radiologist disagreement on an established APSA clinical practice guideline. Inter-rater agreement was good for absolute AAST injury grade (kappa: 0.64 [0.59-0.69]) and excellent for relative AAST injury grade (Kendall w: 0.90). All radiologists agreed on the AAST grade in 52% of cases. Based on an established clinical practice guideline, radiologist disagreement could have changed the decision for intensive care management in 11% (10/90) of children, changed the length of hospital stay in 44% (40/90), and changed the time to return to normal activity in 44% (40/90). Radiologist agreement when assigning splenic AAST injury grades is less than perfect, and disagreements have the potential to change management in a substantial number of pediatric patients. (orig.)

Inter-radiologist agreement for CT scoring of pediatric splenic injuries and effect on an established clinical practice guideline

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Leschied, Jessica R.; Smith, Ethan A.; Ladino-Torres, Maria F.; Dillman, Jonathan R. [University of Michigan Health System, Department of Radiology, Section of Pediatric Radiology, C.S. Mott Children' s Hospital, Ann Arbor, MI (United States); Mazza, Michael B.; Chong, Suzanne T.; Hoff, Carrie N. [University of Michigan Health System, Department of Radiology, Division of Emergency Radiology, C.S. Mott Children' s Hospital, Ann Arbor, MI (United States); Davenport, Matthew S. [University of Michigan Health System, Department of Radiology, Division of Abdominal Imaging, C.S. Mott Children' s Hospital, Ann Arbor, MI (United States); Khalatbari, Shokoufeh [University of Michigan, Michigan Institute for Clinical and Health Research, Ann Arbor, MI (United States); Ehrlich, Peter F. [University of Michigan Health System, Department of Surgery, Section of Pediatric Surgery, C.S. Mott Children' s Hospital, Ann Arbor, MI (United States)

2016-02-15

The American Pediatric Surgical Association (APSA) advocates for the use of a clinical practice guideline to direct management of hemodynamically stable pediatric spleen injuries. The clinical practice guideline is based on the CT score of the spleen injury according to the American Association for the Surgery of Trauma (AAST) CT scoring system. To determine the potential effect of radiologist agreement for CT scoring of pediatric spleen injuries on an established APSA clinical practice guideline. We retrospectively analyzed blunt splenic injuries occurring in children from January 2007 to January 2012 at a single level 1 trauma center (n = 90). Abdominal CT exams performed at clinical presentation were reviewed by four radiologists who documented the following: (1) splenic injury grade (AAST system), (2) arterial extravasation and (3) pseudoaneurysm. Inter-rater agreement for AAST injury grade was assessed using the multi-rater Fleiss kappa and Kendall coefficient of concordance. Inter-rater agreement was assessed using weighted (AAST injury grade) or prevalence-adjusted bias-adjusted (binary measures) kappa statistics; 95% confidence intervals were calculated. We evaluated the hypothetical effect of radiologist disagreement on an established APSA clinical practice guideline. Inter-rater agreement was good for absolute AAST injury grade (kappa: 0.64 [0.59-0.69]) and excellent for relative AAST injury grade (Kendall w: 0.90). All radiologists agreed on the AAST grade in 52% of cases. Based on an established clinical practice guideline, radiologist disagreement could have changed the decision for intensive care management in 11% (10/90) of children, changed the length of hospital stay in 44% (40/90), and changed the time to return to normal activity in 44% (40/90). Radiologist agreement when assigning splenic AAST injury grades is less than perfect, and disagreements have the potential to change management in a substantial number of pediatric patients. (orig.)

Pediatric imaging essentials. Radiography, ultrasound, CT, and MRI in neonates and children

International Nuclear Information System (INIS)

Riccabona, Michael

2014-01-01

For all radiologists treating infants and children, knowledge of best practices in pediatric imaging is essential to safely obtaining high-quality images and achieving accurate diagnoses. This practical text covers current guidelines and key topics in the field, including choice of modality, equipment and dosages, child-specific diseases, typical imaging findings, differential diagnostic aspects and safety factors. This book is invaluable for all clinicians and radiologists who diagnose and manage this sensitive population. Special features: - Explores the use of all standard imaging modalities in children as compared to adults, especially with regard to ultrasound, CT, and MRI - Supplies more than 600 high-quality images to help in interpreting findings, including imaging of suspected child abuse - Shows how to adapt examination protocols and equipment requirements for the specialized needs of pediatric patients - Describes important safety protection measures in children utilizing the ALARA principle of radiation exposure (''As Low As Reasonably Achievable'') - Summarizes a wide array of pediatric diseases and disorders in a concise, checklist format, including clinical features, imaging findings, differential diagnosis, associated syndromes, and treatment recommendations - Includes lists of indications, summary tables, imaging protocols, case studies, and quiz questions to test your knowledge This book provides a fundamental understanding of imaging in infants and children and is an ideal, practice-oriented reference for residents, fellows in pediatric radiology, and general radiologists. It is also written for pediatricians, pediatric surgeons, and other interested doctors and specialists who want to know more about imaging specifics in the pediatric age group.

Pediatric imaging essentials. Radiography, ultrasound, CT, and MRI in neonates and children

Energy Technology Data Exchange (ETDEWEB)

Riccabona, Michael (ed.) [Graz University Hospital (Austria). Div. of Pediatric Radiology

2014-03-01

For all radiologists treating infants and children, knowledge of best practices in pediatric imaging is essential to safely obtaining high-quality images and achieving accurate diagnoses. This practical text covers current guidelines and key topics in the field, including choice of modality, equipment and dosages, child-specific diseases, typical imaging findings, differential diagnostic aspects and safety factors. This book is invaluable for all clinicians and radiologists who diagnose and manage this sensitive population. Special features: - Explores the use of all standard imaging modalities in children as compared to adults, especially with regard to ultrasound, CT, and MRI - Supplies more than 600 high-quality images to help in interpreting findings, including imaging of suspected child abuse - Shows how to adapt examination protocols and equipment requirements for the specialized needs of pediatric patients - Describes important safety protection measures in children utilizing the ALARA principle of radiation exposure (''As Low As Reasonably Achievable'') - Summarizes a wide array of pediatric diseases and disorders in a concise, checklist format, including clinical features, imaging findings, differential diagnosis, associated syndromes, and treatment recommendations - Includes lists of indications, summary tables, imaging protocols, case studies, and quiz questions to test your knowledge This book provides a fundamental understanding of imaging in infants and children and is an ideal, practice-oriented reference for residents, fellows in pediatric radiology, and general radiologists. It is also written for pediatricians, pediatric surgeons, and other interested doctors and specialists who want to know more about imaging specifics in the pediatric age group.

Optimization of a miniature Maglev ventricular assist device for pediatric circulatory support.

Science.gov (United States)

Zhang, Juntao; Koert, Andrew; Gellman, Barry; Gempp, Thomas M; Dasse, Kurt A; Gilbert, Richard J; Griffith, Bartley P; Wu, Zhongjun J

2007-01-01

A miniature Maglev blood pump based on magnetically levitated bearingless technology is being developed and optimized for pediatric patients. We performed impeller optimization by characterizing the hemodynamic and hemocompatibility performances using a combined computational and experimental approach. Both three-dimensional flow features and hemolytic characteristics were analyzed using computational fluid dynamics (CFD) modeling. Hydraulic pump performances and hemolysis levels of three different impeller designs were quantified and compared numerically. Two pump prototypes were constructed from the two impeller designs and experimentally tested. Comparison of CFD predictions with experimental results showed good agreement. The optimized impeller remarkably increased overall pump hydraulic output by more than 50% over the initial design. The CFD simulation demonstrated a clean and streamlined flow field in the main flow path. The numerical results by hemolysis model indicated no significant high shear stress regions. Through the use of CFD analysis and bench-top testing, the small pediatric pump was optimized to achieve a low level of blood damage and improved hydraulic performance and efficiency. The Maglev pediatric blood pump is innovative due to its small size, very low priming volume, excellent hemodynamic and hematologic performance, and elimination of seal-related and bearing-related failures due to adoption of magnetically levitated bearingless motor technology, making it ideal for pediatric applications.

Spectral optimization for micro-CT

International Nuclear Information System (INIS)

Hupfer, Martin; Nowak, Tristan; Brauweiler, Robert; Eisa, Fabian; Kalender, Willi A.

2012-01-01

Purpose: To optimize micro-CT protocols with respect to x-ray spectra and thereby reduce radiation dose at unimpaired image quality. Methods: Simulations were performed to assess image contrast, noise, and radiation dose for different imaging tasks. The figure of merit used to determine the optimal spectrum was the dose-weighted contrast-to-noise ratio (CNRD). Both optimal photon energy and tube voltage were considered. Three different types of filtration were investigated for polychromatic x-ray spectra: 0.5 mm Al, 3.0 mm Al, and 0.2 mm Cu. Phantoms consisted of water cylinders of 20, 32, and 50 mm in diameter with a central insert of 9 mm which was filled with different contrast materials: an iodine-based contrast medium (CM) to mimic contrast-enhanced (CE) imaging, hydroxyapatite to mimic bone structures, and water with reduced density to mimic soft tissue contrast. Validation measurements were conducted on a commercially available micro-CT scanner using phantoms consisting of water-equivalent plastics. Measurements on a mouse cadaver were performed to assess potential artifacts like beam hardening and to further validate simulation results. Results: The optimal photon energy for CE imaging was found at 34 keV. For bone imaging, optimal energies were 17, 20, and 23 keV for the 20, 32, and 50 mm phantom, respectively. For density differences, optimal energies varied between 18 and 50 keV for the 20 and 50 mm phantom, respectively. For the 32 mm phantom and density differences, CNRD was found to be constant within 2.5% for the energy range of 21–60 keV. For polychromatic spectra and CMs, optimal settings were 50 kV with 0.2 mm Cu filtration, allowing for a dose reduction of 58% compared to the optimal setting for 0.5 mm Al filtration. For bone imaging, optimal tube voltages were below 35 kV. For soft tissue imaging, optimal tube settings strongly depended on phantom size. For 20 mm, low voltages were preferred. For 32 mm, CNRD was found to be almost independent

Spectral optimization for micro-CT.

Science.gov (United States)

Hupfer, Martin; Nowak, Tristan; Brauweiler, Robert; Eisa, Fabian; Kalender, Willi A

2012-06-01

To optimize micro-CT protocols with respect to x-ray spectra and thereby reduce radiation dose at unimpaired image quality. Simulations were performed to assess image contrast, noise, and radiation dose for different imaging tasks. The figure of merit used to determine the optimal spectrum was the dose-weighted contrast-to-noise ratio (CNRD). Both optimal photon energy and tube voltage were considered. Three different types of filtration were investigated for polychromatic x-ray spectra: 0.5 mm Al, 3.0 mm Al, and 0.2 mm Cu. Phantoms consisted of water cylinders of 20, 32, and 50 mm in diameter with a central insert of 9 mm which was filled with different contrast materials: an iodine-based contrast medium (CM) to mimic contrast-enhanced (CE) imaging, hydroxyapatite to mimic bone structures, and water with reduced density to mimic soft tissue contrast. Validation measurements were conducted on a commercially available micro-CT scanner using phantoms consisting of water-equivalent plastics. Measurements on a mouse cadaver were performed to assess potential artifacts like beam hardening and to further validate simulation results. The optimal photon energy for CE imaging was found at 34 keV. For bone imaging, optimal energies were 17, 20, and 23 keV for the 20, 32, and 50 mm phantom, respectively. For density differences, optimal energies varied between 18 and 50 keV for the 20 and 50 mm phantom, respectively. For the 32 mm phantom and density differences, CNRD was found to be constant within 2.5% for the energy range of 21-60 keV. For polychromatic spectra and CMs, optimal settings were 50 kV with 0.2 mm Cu filtration, allowing for a dose reduction of 58% compared to the optimal setting for 0.5 mm Al filtration. For bone imaging, optimal tube voltages were below 35 kV. For soft tissue imaging, optimal tube settings strongly depended on phantom size. For 20 mm, low voltages were preferred. For 32 mm, CNRD was found to be almost independent of tube voltage. For 50 mm

Individualized volume CT dose index determined by cross-sectional area and mean density of the body to achieve uniform image noise of contrast-enhanced pediatric chest CT obtained at variable kV levels and with combined tube current modulation

International Nuclear Information System (INIS)

Goo, Hyun Woo

2011-01-01

A practical body-size adaptive protocol providing uniform image noise at various kV levels is not available for pediatric CT. To develop a practical contrast-enhanced pediatric chest CT protocol providing uniform image noise by using an individualized volume CT dose index (CTDIvol) determined by the cross-sectional area and density of the body at variable kV levels and with combined tube current modulation. A total of 137 patients (mean age, 7.6 years) underwent contrast-enhanced pediatric chest CT based on body weight. From the CTDIvol, image noise, and area and mean density of the cross-section at the lung base in the weight-based group, the best fit equation was estimated with a very high correlation coefficient (γ 2 = 0.86, P 2 vs. 326.3 ± 124.8 cm 2 ), mean density (-212.9 ± 53.1 HU vs. -221.1 ± 56.3 HU), and image noise (13.8 ± 2.3 vs. 13.6 ± 1.7 HU) between the weight-based and the CTDIvol groups (P > 0.05). Contrast-enhanced pediatric chest CT with the CTDIvol determined individually by the cross-sectional area and density of the body provides more uniform noise and better dose adaptation to body habitus than does weight-based CT at variable kV levels and with combined tube current modulation. (orig.)

Risk and Resilience in Pediatric Chronic Pain: Exploring the Protective Role of Optimism.

Science.gov (United States)

Cousins, Laura A; Cohen, Lindsey L; Venable, Claudia

2015-10-01

Fear of pain and pain catastrophizing are prominent risk factors for pediatric chronic pain-related maladjustment. Although resilience has largely been ignored in the pediatric pain literature, prior research suggests that optimism might benefit youth and can be learned. We applied an adult chronic pain risk-resilience model to examine the interplay of risk factors and optimism on functioning outcomes in youth with chronic pain. Participants included 58 children and adolescents (8-17 years) attending a chronic pain clinic and their parents. Participants completed measures of fear of pain, pain catastrophizing, optimism, disability, and quality of life. Consistent with the literature, pain intensity, fear of pain, and catastrophizing predicted functioning. Optimism was a unique predictor of quality of life, and optimism contributed to better functioning by minimizing pain-related fear and catastrophizing. Optimism might be protective and offset the negative influence of fear of pain and catastrophizing on pain-related functioning. © The Author 2014. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A novel spliced fusion of MLL with CT45A2 in a pediatric biphenotypic acute leukemia

International Nuclear Information System (INIS)

Cerveira, Nuno; Marschalek, Rolf; Teixeira, Manuel R; Meyer, Claus; Santos, Joana; Torres, Lurdes; Lisboa, Susana; Pinheiro, Manuela; Bizarro, Susana; Correia, Cecília; Norton, Lucília

2010-01-01

Abnormalities of 11q23 involving the MLL gene are found in approximately 10% of human leukemias. To date, nearly 100 different chromosome bands have been described in rearrangements involving 11q23 and 64 fusion genes have been cloned and characterized at the molecular level. In this work we present the identification of a novel MLL fusion partner in a pediatric patient with de novo biphenotypic acute leukemia. Cytogenetics, fluorescence in situ hybridization (FISH), molecular studies (RT-PCR and LDI-PCR), and bioinformatic sequence analysis were used to characterize the CT45A2 gene as novel MLL fusion partner in pediatric acute leukemia. Fluorescence in situ hybridization of bone marrow G-banded metaphases demonstrated a cryptic insertion of 11q23 in Xq26.3 involving the MLL gene. Breakpoint fusion analysis revealed that a DNA fragment of 653 kb from 11q23, containing MLL exons 1-9 in addition to 16 other 11q23 genes, was inserted into the upstream region of the CT45A2 gene located at Xq26.3. In addition, a deletion at Xq26.3 encompassing the 3' region of the DDX26B gene (exons 9-16) and the entire CT45A1 gene was identified. RNA analysis revealed the presence of a novel MLL-CT45A2 fusion transcript in which the first 9 exons of the MLL gene were fused in-frame to exon 2 of the CT45A2 gene, resulting in a spliced MLL fusion transcript with an intact open reading frame. The resulting chimeric transcript predicts a fusion protein where the N-terminus of MLL is fused to the entire open reading frame of CT45A2. Finally, we demonstrate that all breakpoint regions are rich in long repetitive motifs, namely LINE/L1 and SINE/Alu sequences, but all breakpoints were exclusively identified outside these repetitive DNA sequences. We have identified CT45A2 as a novel spliced MLL fusion partner in a pediatric patient with de novo biphenotypic acute leukemia, as a result of a cryptic insertion of 11q23 in Xq26.3. Since CT45A2 is the first Cancer/Testis antigen family gene

A set of 4D pediatric XCAT reference phantoms for multimodality research

International Nuclear Information System (INIS)

Norris, Hannah; Zhang, Yakun; Bond, Jason; Sturgeon, Gregory M.; Samei, E.; Segars, W. P.; Minhas, Anum; Frush, D.; Tward, Daniel J.; Ratnanather, J. T.; Miller, M. I.

2014-01-01

Purpose: The authors previously developed an adult population of 4D extended cardiac-torso (XCAT) phantoms for multimodality imaging research. In this work, the authors develop a reference set of 4D pediatric XCAT phantoms consisting of male and female anatomies at ages of newborn, 1, 5, 10, and 15 years. These models will serve as the foundation from which the authors will create a vast population of pediatric phantoms for optimizing pediatric CT imaging protocols. Methods: Each phantom was based on a unique set of CT data from a normal patient obtained from the Duke University database. The datasets were selected to best match the reference values for height and weight for the different ages and genders according to ICRP Publication 89. The major organs and structures were segmented from the CT data and used to create an initial pediatric model defined using nonuniform rational B-spline surfaces. The CT data covered the entire torso and part of the head. To complete the body, the authors manually added on the top of the head and the arms and legs using scaled versions of the XCAT adult models or additional models created from cadaver data. A multichannel large deformation diffeomorphic metric mapping algorithm was then used to calculate the transform from a template XCAT phantom (male or female 50th percentile adult) to the target pediatric model. The transform was applied to the template XCAT to fill in any unsegmented structures within the target phantom and to implement the 4D cardiac and respiratory models in the new anatomy. The masses of the organs in each phantom were matched to the reference values given in ICRP Publication 89. The new reference models were checked for anatomical accuracy via visual inspection. Results: The authors created a set of ten pediatric reference phantoms that have the same level of detail and functionality as the original XCAT phantom adults. Each consists of thousands of anatomical structures and includes parameterized models

A set of 4D pediatric XCAT reference phantoms for multimodality research

Energy Technology Data Exchange (ETDEWEB)

Norris, Hannah, E-mail: Hannah.norris@duke.edu; Zhang, Yakun; Bond, Jason; Sturgeon, Gregory M.; Samei, E.; Segars, W. P. [Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Minhas, Anum; Frush, D. [Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Tward, Daniel J.; Ratnanather, J. T.; Miller, M. I. [Center for Imaging Science, Johns Hopkins University, Baltimore, Maryland 21218 (United States)

2014-03-15

Purpose: The authors previously developed an adult population of 4D extended cardiac-torso (XCAT) phantoms for multimodality imaging research. In this work, the authors develop a reference set of 4D pediatric XCAT phantoms consisting of male and female anatomies at ages of newborn, 1, 5, 10, and 15 years. These models will serve as the foundation from which the authors will create a vast population of pediatric phantoms for optimizing pediatric CT imaging protocols. Methods: Each phantom was based on a unique set of CT data from a normal patient obtained from the Duke University database. The datasets were selected to best match the reference values for height and weight for the different ages and genders according to ICRP Publication 89. The major organs and structures were segmented from the CT data and used to create an initial pediatric model defined using nonuniform rational B-spline surfaces. The CT data covered the entire torso and part of the head. To complete the body, the authors manually added on the top of the head and the arms and legs using scaled versions of the XCAT adult models or additional models created from cadaver data. A multichannel large deformation diffeomorphic metric mapping algorithm was then used to calculate the transform from a template XCAT phantom (male or female 50th percentile adult) to the target pediatric model. The transform was applied to the template XCAT to fill in any unsegmented structures within the target phantom and to implement the 4D cardiac and respiratory models in the new anatomy. The masses of the organs in each phantom were matched to the reference values given in ICRP Publication 89. The new reference models were checked for anatomical accuracy via visual inspection. Results: The authors created a set of ten pediatric reference phantoms that have the same level of detail and functionality as the original XCAT phantom adults. Each consists of thousands of anatomical structures and includes parameterized models

Evolving role of 18F-FDG-PET/CT for the body tumor and metastases in pediatrics

International Nuclear Information System (INIS)

Chen Zhengguang; Li Xiaozhen; Li Fang; Ouyang Qiaohong; Yu Tong

2010-01-01

18 F-FDG-positron emission tomography-computerized tomography ( 18 F-FDG-PET/CT) scan is an important imaging tool which may provide both functional and anatomical information in a single diagnostic test. It has the potential to be a valuable tool in the noninvasive evaluation and monitoring of pediatric tumors including the metastases because 18 fluorodeoxyglucose ( 18 F-FDG) is a glucose analogue that concentrates in areas of active metabolic activity. This review provides an update on functional and metabolic imaging approaches for assessment and management of the body tumor and metastases in pediatrics using a combined whole body 18 F-FDG-PET/CT scanners. We discuss the benefits include improved pediatric patients' outcome facilitated by staging and monitoring of disease and better treatment planning. It is worth to concern the preparation of children undergoing PET studies and radiation dosimetry and its implications for family and caregivers. It is important to consider the normal distribution of 18 FDG in children, common variations of the normal distribution. We show some of our cases that most tumors in children accumulate and retain FDG, allowing high-quality images of their distribution and pathophysiology either at the primary site as well as in the areas of metastatic disease.

CT radiation dose and image quality optimization using a porcine model.

Science.gov (United States)

Zarb, Francis; McEntee, Mark F; Rainford, Louise

2013-01-01

To evaluate potential radiation dose savings and resultant image quality effects with regard to optimization of commonly performed computed tomography (CT) studies derived from imaging a porcine (pig) model. Imaging protocols for 4 clinical CT suites were developed based on the lowest milliamperage and kilovoltage, the highest pitch that could be set from current imaging protocol parameters, or both. This occurred before significant changes in noise, contrast, and spatial resolution were measured objectively on images produced from a quality assurance CT phantom. The current and derived phantom protocols were then applied to scan a porcine model for head, abdomen, and chest CT studies. Further optimized protocols were developed based on the same methodology as in the phantom study. The optimization achieved with respect to radiation dose and image quality was evaluated following data collection of radiation dose recordings and image quality review. Relative visual grading analysis of image quality criteria adapted from the European guidelines on radiology quality criteria for CT were used for studies completed with both the phantom-based or porcine-derived imaging protocols. In 5 out of 16 experimental combinations, the current clinical protocol was maintained. In 2 instances, the phantom protocol reduced radiation dose by 19% to 38%. In the remaining 9 instances, the optimization based on the porcine model further reduced radiation dose by 17% to 38%. The porcine model closely reflects anatomical structures in humans, allowing the grading of anatomical criteria as part of image quality review without radiation risks to human subjects. This study demonstrates that using a porcine model to evaluate CT optimization resulted in more radiation dose reduction than when imaging protocols were tested solely on quality assurance phantoms.

SU-F-I-32: Organ Doses from Pediatric Head CT Scan

Energy Technology Data Exchange (ETDEWEB)

Liu, H; Liu, Q; Qiu, J; Zhuo, W [Institute of Radiation Medicine Fudan University, Shanghai (China); Majer, M; Knezevic, Z; Miljanic, S [Radiation Chemistry and Dosimetry Laboratory, Ruder Boskovic Institute, Zagreb (Croatia); Hrsak, H [Clinical Hospital Centre Zagreb, Zagreb (Croatia)

2016-06-15

Purpose: To evaluate the organ doses of pediatric patients who undergoing head CT scan using Monte Carlo (MC) simulation and compare it with measurements in anthropomorphic child phantom.. Methods: A ten years old children voxel phantom was developed from CT images, the voxel size of the phantom was 2mm*2mm*2mm. Organ doses from head CT scan were simulated using MCNPX software, 180 detectors were placed in the voxel phantom to tally the doses of the represented tissues or organs. When performing the simulation, 120 kVp and 88 mA were selected as the scan parameters. The scan range covered from the top of the head to the end of the chain, this protocol was used at CT simulator for radiotherapy. To validate the simulated results, organ doses were measured with radiophotoluminescence (RPL) detectors, placed in the 28 organs of the 10 years old CIRS ATOM phantom. Results: The organ doses results matched well between MC simulation and phantom measurements. The eyes dose was showed to be as expected the highest organ dose: 28.11 mGy by simulation and 27.34 mGy by measurement respectively. Doses for organs not included in the scan volume were much lower than those included in the scan volume, thymus doses were observed more than 10 mGy due the CT protocol for radiotherapy covered more body part than routine head CT scan. Conclusion: As the eyes are superficial organs, they may receive the highest radiation dose during the CT scan. Considering the relatively high radio sensitivity, using shielding material or organ based tube current modulation technique should be encouraged to reduce the eye radiation risks. Scan range was one of the most important factors that affects the organ doses during the CT scan. Use as short as reasonably possible scan range should be helpful to reduce the patient radiation dose. This work was supported by the National Natural Science Foundation of China(11475047)

Optimizing Perioperative Nutrition in Pediatric Populations.

Science.gov (United States)

Canada, Nicki L; Mullins, Lucille; Pearo, Brittany; Spoede, Elizabeth

2016-02-01

Nutrition status prior to surgery and nutrition rehabilitation after surgery can affect the morbidity and mortality of pediatric patients. A comprehensive approach to nutrition in pediatric surgical patients is important and includes preoperative assessment, perioperative nutrition considerations, and postoperative recovery. A thorough nutrition assessment to identify patients who are at nutrition risk prior to surgery is important so that the nutrition status can be optimized prior to the procedure to minimize suboptimal outcomes. Preoperative malnutrition is associated with increased complications and mean hospital days following surgery. Enteral and parenteral nutrition can be used in cases where food intake is inadequate to maintain and possibly improve nutrition status, especially in the 7-10 days prior to surgery. In the perioperative period, fasting should be limited to restricting solid foods and non-human milk 6 hours prior to the procedure and allowing clear liquids until 2 hours prior to the procedure. Postoperatively, early feeding has been shown to resolve postoperative ileus earlier, decrease infection rates, promote wound healing, and reduce length of hospital stay. If nutrition cannot be provided orally, then nutrition through either enteral or parenteral means should be initiated within 24-48 hours of surgery. Practitioners should identify those patients who are at the highest nutrition risk for postsurgical complications and provide guidance for optimal nutrition during the perioperative and postoperative period. © 2015 American Society for Parenteral and Enteral Nutrition.

Noise and dose modeling for pediatric CT optimization: preliminary results

International Nuclear Information System (INIS)

Miller Clemente, Rafael A.; Perez Diaz, Marlen; Mora Reyes, Yudel; Rodriguez Garlobo, Maikel; Castillo Salazar, Rafael

2008-01-01

Full text: A Multiple Linear Regression Model was developed to predict noise and dose in computed tomography pediatric imaging for head and abdominal examinations. Relative values of Noise and Volumetric Computed Tomography Dose Index was used to estimate de model respectively. 54 images of physical phantoms were performed. Independent variables considered included: phantom diameter, tube current and kilovolts, x ray beam collimation, reconstruction diameter and equipment's post processing filters. Predicted values show good agreement with measurements, which were better in noise model (R 2 adjusted =0.953) than the dose model (R 2 adjusted =0.744). Tube current, object diameter, beam collimation and reconstruction filter were identified as the most influencing factors in models. (author)

TU-FG-BRB-04: A New Optimization Method for Pre-Treatment Patient-Specific Stopping-Power by Combining Proton Radiography and X-Ray CT

International Nuclear Information System (INIS)

Collins-Fekete, C; Schulte, R; Beaulieu, L; Seco, J

2016-01-01

Purpose: The relative stopping power (RSP) uncertainty is the largest contributor to the range uncertainty in proton therapy. The purpose of this work is to develop a robust and systematic method that yields accurate patient specific RSPs by combining pre-treatment X-ray CT and daily proton radiography. Methods: The method is formulated as a penalized least squares optimization (PLSO) problem min(|Ax-B|). The matrix A represents the cumulative path-length crossed in each material computed by calculating proton trajectories through the X-ray CT. The material RSPs are denoted by x and B is the pRad, expressed as water equivalent thickness. The equation is solved using a convex-conic optimizer. Geant4 simulations were made to assess the feasibility of the method. RSP extracted from the Geant4 materials were used as a reference and the clinical HU-RSP curve as a comparison. The PLSO was first tested on a Gammex RMI-467 phantom. Then, anthropomorphic phantoms of the head, pelvis and lung were studied and resulting RSPs were evaluated. A pencil beam was generated in each phantom to evaluate the proton range accuracy achievable by using the optimized RSPs. Finally, experimental data of a pediatric head phantom (CIRS) were acquired using a recently completed experimental pCT scanner. Results: Numerical simulations showed precise RSP (<0.75%) for Gammex materials except low-density lung (LN-300) (1.2%). Accurate RSP have been obtained for the head (µ=−0.10%, 1.5σ=1.12%), lung (µ=−0.33, 1.5σ=1.02%) and pelvis anthropomorphic phantoms (µ=0.12, 1.5σ=0,99%). The range precision has been improved with an average R80 difference to the reference (µ±1.5σ) of −0.20±0.35%, −0.47±0.92% and −0.06±0.17% in the head, lung and pelvis phantoms respectively, compared to the 3.5% clinical margin. Experimental HU-RSP curve have been produced on the CIRS pediatric head. Conclusion: The proposed PLSO with prior knowledge X-ray CT shows promising potential (R80 σ<1.0% over

Quality of pediatric abdominal CT scans performed at a dedicated children's hospital and its referring institutions: a multifactorial evaluation

International Nuclear Information System (INIS)

Snow, Aisling; Milliren, Carly E.; Graham, Dionne A.; Callahan, Michael J.; MacDougall, Robert D.; Robertson, Richard L.; Taylor, George A.

2017-01-01

Pediatric patients requiring transfer to a dedicated children's hospital from an outside institution may undergo CT imaging as part of their evaluation. Whether this imaging is performed prior to or after transfer has been shown to impact the radiation dose imparted to the patient. Other quality variables could also be affected by the pediatric experience and expertise of the scanning institution. To identify differences in quality between abdominal CT scans and reports performed at a dedicated children's hospital, and those performed at referring institutions. Fifty consecutive pediatric abdominal CT scans performed at outside institutions were matched (for age, gender and indication) with 50 CT scans performed at a dedicated freestanding children's hospital. We analyzed the scans for technical parameters, report findings, correlation with final clinical diagnosis, and clinical utility. Technical evaluation included use of intravenous and oral contrast agents, anatomical coverage, number of scan phases and size-specific dose estimate (SSDE) for each scan. Outside institution scans were re-reported when the child was admitted to the children's hospital; they were also re-interpreted for this study by children's hospital radiologists who were provided with only the referral information given in the outside institution's report. Anonymized original outside institutional reports and children's hospital admission re-reports were analyzed by two emergency medicine physicians for ease of understanding, degree to which the clinical question was answered, and level of confidence in the report. Mean SSDE was lower (8.68) for children's hospital scans, as compared to outside institution scans (13.29, P = 0.03). Concordance with final clinical diagnosis was significantly lower for original outside institution reports (38/48, 79%) than for both the admission and study children's hospital reports (48/50, 96%; P = 0.005). Children's hospital admission reports were rated higher

Patient doses in chest CT examinations: Comparison of various CT scanners

Directory of Open Access Journals (Sweden)

Božović Predrag

2013-01-01

Full Text Available This paper presents results from study on patient exposure level in chest CT examinations. CT scanners used in this study were various Siemens and General Electric (GE models. Data on patient doses were collected for adult and pediatric patients. Doses measured for adult patients were lower then those determined as Diagnostic Reference Levels (DRL for Europe, while doses for pediatric patients were similar to those found in published data. As for the manufactures, slightly higher doses were measured on GE devices, both for adult and pediatric patients.

Optimization of Proton CT Detector System and Image Reconstruction Algorithm for On-Line Proton Therapy.

Directory of Open Access Journals (Sweden)

Chae Young Lee

Full Text Available The purposes of this study were to optimize a proton computed tomography system (pCT for proton range verification and to confirm the pCT image reconstruction algorithm based on projection images generated with optimized parameters. For this purpose, we developed a new pCT scanner using the Geometry and Tracking (GEANT 4.9.6 simulation toolkit. GEANT4 simulations were performed to optimize the geometric parameters representing the detector thickness and the distance between the detectors for pCT. The system consisted of four silicon strip detectors for particle tracking and a calorimeter to measure the residual energies of the individual protons. The optimized pCT system design was then adjusted to ensure that the solution to a CS-based convex optimization problem would converge to yield the desired pCT images after a reasonable number of iterative corrections. In particular, we used a total variation-based formulation that has been useful in exploiting prior knowledge about the minimal variations of proton attenuation characteristics in the human body. Examinations performed using our CS algorithm showed that high-quality pCT images could be reconstructed using sets of 72 projections within 20 iterations and without any streaks or noise, which can be caused by under-sampling and proton starvation. Moreover, the images yielded by this CS algorithm were found to be of higher quality than those obtained using other reconstruction algorithms. The optimized pCT scanner system demonstrated the potential to perform high-quality pCT during on-line image-guided proton therapy, without increasing the imaging dose, by applying our CS based proton CT reconstruction algorithm. Further, we make our optimized detector system and CS-based proton CT reconstruction algorithm potentially useful in on-line proton therapy.

18F-FDG PET/CT compared to conventional imaging modalities in pediatric primary bone tumors

International Nuclear Information System (INIS)

London, Kevin; Stege, Claudia; Kaspers, Gertjan; Cross, Siobhan; Dalla-Pozza, Luciano; Onikul, Ella; Graf, Nicole; Howman-Giles, Robert

2012-01-01

F-Fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) is useful in adults with primary bone tumors. Limited published data exist in children. To compare hybrid FDG positron emission tomography/computed tomography (PET/CT) with conventional imaging (CI) modalities in detecting malignant lesions, predicting response to chemotherapy and diagnosing physeal involvement in pediatric primary bone tumors. Retrospective analysis of PET/CT and CI reports with histopathology or follow-up > 6 months as reference standard. Response parameters and physeal involvement at diagnosis were compared to histopathology. A total of 314 lesions were detected in 86 scans. Excluding lung lesions, PET/CT had higher sensitivity and specificity than CI (83%, 98% and 78%, 97%, respectively). In lung lesions, PET/CT had higher specificity than CI (96% compared to 87%) but lower sensitivity (80% compared to 93%). Higher initial SUV max and greater SUV max reduction on PET/CT after chemotherapy predicted a good response. Change in tumor size on MRI did not predict response. Both PET/CT and MRI were very sensitive but of low specificity in predicting physeal tumor involvement. PET/CT appears more accurate than CI in detecting malignant lesions in childhood primary bone tumors, excluding lung lesions. It seems better than MRI at predicting tumor response to chemotherapy. (orig.)

Individualized volume CT dose index determined by cross-sectional area and mean density of the body to achieve uniform image noise of contrast-enhanced pediatric chest CT obtained at variable kV levels and with combined tube current modulation

Energy Technology Data Exchange (ETDEWEB)

Goo, Hyun Woo [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of)

2011-07-15

A practical body-size adaptive protocol providing uniform image noise at various kV levels is not available for pediatric CT. To develop a practical contrast-enhanced pediatric chest CT protocol providing uniform image noise by using an individualized volume CT dose index (CTDIvol) determined by the cross-sectional area and density of the body at variable kV levels and with combined tube current modulation. A total of 137 patients (mean age, 7.6 years) underwent contrast-enhanced pediatric chest CT based on body weight. From the CTDIvol, image noise, and area and mean density of the cross-section at the lung base in the weight-based group, the best fit equation was estimated with a very high correlation coefficient ({gamma}{sup 2} = 0.86, P < 0.001). For the next study, 177 patients (mean age, 7.9 years; the CTDIvol group) underwent contrast-enhanced pediatric chest CT with the CTDIvol determined individually by the best fit equation. CTDIvol values on the dose report after CT scanning, noise differences from the target noise, areas, and mean densities were compared between these two groups. The CTDIvol values (mean{+-}standard deviation, 1.6 {+-} 0.7 mGy) and the noise differences from the target noise (1.1 {+-} 0.9 HU) of the CTDIvol group were significantly lower than those of the weight-based group (2.0 {+-} 1.0 mGy, 1.8 {+-} 1.4 HU) (P < 0.001). In contrast, no statistically significant difference was found in area (317.0 {+-} 136.8 cm{sup 2} vs. 326.3 {+-} 124.8 cm{sup 2}), mean density (-212.9 {+-} 53.1 HU vs. -221.1 {+-} 56.3 HU), and image noise (13.8 {+-} 2.3 vs. 13.6 {+-} 1.7 HU) between the weight-based and the CTDIvol groups (P > 0.05). Contrast-enhanced pediatric chest CT with the CTDIvol determined individually by the cross-sectional area and density of the body provides more uniform noise and better dose adaptation to body habitus than does weight-based CT at variable kV levels and with combined tube current modulation. (orig.)

VirtualDose: a software for reporting organ doses from CT for adult and pediatric patients

Science.gov (United States)

Ding, Aiping; Gao, Yiming; Liu, Haikuan; Caracappa, Peter F.; Long, Daniel J.; Bolch, Wesley E.; Liu, Bob; Xu, X. George

2015-07-01

This paper describes the development and testing of VirtualDose—a software for reporting organ doses for adult and pediatric patients who undergo x-ray computed tomography (CT) examinations. The software is based on a comprehensive database of organ doses derived from Monte Carlo (MC) simulations involving a library of 25 anatomically realistic phantoms that represent patients of different ages, body sizes, body masses, and pregnant stages. Models of GE Lightspeed Pro 16 and Siemens SOMATOM Sensation 16 scanners were carefully validated for use in MC dose calculations. The software framework is designed with the ‘software as a service (SaaS)’ delivery concept under which multiple clients can access the web-based interface simultaneously from any computer without having to install software locally. The RESTful web service API also allows a third-party picture archiving and communication system software package to seamlessly integrate with VirtualDose’s functions. Software testing showed that VirtualDose was compatible with numerous operating systems including Windows, Linux, Apple OS X, and mobile and portable devices. The organ doses from VirtualDose were compared against those reported by CT-Expo and ImPACT—two dosimetry tools that were based on the stylized pediatric and adult patient models that were known to be anatomically simple. The organ doses reported by VirtualDose differed from those reported by CT-Expo and ImPACT by as much as 300% in some of the patient models. These results confirm the conclusion from past studies that differences in anatomical realism offered by stylized and voxel phantoms have caused significant discrepancies in CT dose estimations.

VirtualDose: a software for reporting organ doses from CT for adult and pediatric patients

International Nuclear Information System (INIS)

Ding, Aiping; Gao, Yiming; Liu, Haikuan; Caracappa, Peter F; Xu, X George; Long, Daniel J; Bolch, Wesley E; Liu, Bob

2015-01-01

This paper describes the development and testing of VirtualDose—a software for reporting organ doses for adult and pediatric patients who undergo x-ray computed tomography (CT) examinations. The software is based on a comprehensive database of organ doses derived from Monte Carlo (MC) simulations involving a library of 25 anatomically realistic phantoms that represent patients of different ages, body sizes, body masses, and pregnant stages. Models of GE Lightspeed Pro 16 and Siemens SOMATOM Sensation 16 scanners were carefully validated for use in MC dose calculations. The software framework is designed with the ‘software as a service (SaaS)’ delivery concept under which multiple clients can access the web-based interface simultaneously from any computer without having to install software locally. The RESTful web service API also allows a third-party picture archiving and communication system software package to seamlessly integrate with VirtualDose’s functions. Software testing showed that VirtualDose was compatible with numerous operating systems including Windows, Linux, Apple OS X, and mobile and portable devices. The organ doses from VirtualDose were compared against those reported by CT-Expo and ImPACT—two dosimetry tools that were based on the stylized pediatric and adult patient models that were known to be anatomically simple. The organ doses reported by VirtualDose differed from those reported by CT-Expo and ImPACT by as much as 300% in some of the patient models. These results confirm the conclusion from past studies that differences in anatomical realism offered by stylized and voxel phantoms have caused significant discrepancies in CT dose estimations. (paper)

CT-guided interventions in children

International Nuclear Information System (INIS)

Honnef, D.; Wildberger, J.E.; Schubert, H.; Hohl, C.; Guenther, R.W.; Mahnken, A.

2007-01-01

In pediatric CT-guided interventions specific features have to be taken into account. Due to a lack of cooperation or limited ability to cooperate, procedures are often performed using analgosedation or general anesthesia. To provide radiation protection, justified indication for CT-guided intervention is necessary and sonography and MRI are to be preferred whenever possible. CT examinations also need to be dose-adapted with sequential scanning and a tube voltage and tube current reduction compared to pediatric diagnostic CT studies must be ensured. Gonad shields are recommended for male patients. Biopsy device selection depends on the assumed tumor entity since histology and also immunohistochemical, molecular pathological and cytogenetical analysis are necessary to differentiate pediatric tumors (small, round, blue cell tumors). In addition to diagnostic procedures, therapeutic interventions (drainage, injection therapies, neurolysis, and radiofrequency ablation) can also be used in children and can provide an alternative to surgery in selected cases. With justified indications and precise performance, CT-guided interventions can be successful in pediatric patients with limited risks. (orig.)

Pediatric CT: implementation of ASIR for substantial radiation dose reduction while maintaining pre-ASIR image noise.

Science.gov (United States)

Brady, Samuel L; Moore, Bria M; Yee, Brian S; Kaufman, Robert A

2014-01-01

To determine a comprehensive method for the implementation of adaptive statistical iterative reconstruction (ASIR) for maximal radiation dose reduction in pediatric computed tomography (CT) without changing the magnitude of noise in the reconstructed image or the contrast-to-noise ratio (CNR) in the patient. The institutional review board waived the need to obtain informed consent for this HIPAA-compliant quality analysis. Chest and abdominopelvic CT images obtained before ASIR implementation (183 patient examinations; mean patient age, 8.8 years ± 6.2 [standard deviation]; range, 1 month to 27 years) were analyzed for image noise and CNR. These measurements were used in conjunction with noise models derived from anthropomorphic phantoms to establish new beam current-modulated CT parameters to implement 40% ASIR at 120 and 100 kVp without changing noise texture or magnitude. Image noise was assessed in images obtained after ASIR implementation (492 patient examinations; mean patient age, 7.6 years ± 5.4; range, 2 months to 28 years) the same way it was assessed in the pre-ASIR analysis. Dose reduction was determined by comparing size-specific dose estimates in the pre- and post-ASIR patient cohorts. Data were analyzed with paired t tests. With 40% ASIR implementation, the average relative dose reduction for chest CT was 39% (2.7/4.4 mGy), with a maximum reduction of 72% (5.3/18.8 mGy). The average relative dose reduction for abdominopelvic CT was 29% (4.8/6.8 mGy), with a maximum reduction of 64% (7.6/20.9 mGy). Beam current modulation was unnecessary for patients weighing 40 kg or less. The difference between 0% and 40% ASIR noise magnitude was less than 1 HU, with statistically nonsignificant increases in patient CNR at 100 kVp of 8% (15.3/14.2; P = .41) for chest CT and 13% (7.8/6.8; P = .40) for abdominopelvic CT. Radiation dose reduction at pediatric CT was achieved when 40% ASIR was implemented as a dose reduction tool only; no net change to the magnitude

SU-G-206-08: How Should Focal Spot Be Chosen for Optimized CT Imaging with Dose Modulation?

Energy Technology Data Exchange (ETDEWEB)

Bache, S; Liu, X; Rong, J [UT MD Anderson Cancer Center, Houston, TX (United States)

2016-06-15

Purpose: To choose the preferred focal spot for achieving optimized CT image quality with balanced tube heating considerations. Methods: An anthropomorphic pelvic phantom was scanned using a GE Discovery CT750 HD at 120 and 140kVp, 0.8s rotation time, and pitch of 0.984. “Smart mA” was enabled to simulate a routine abdomen–pelvis CT scan. Permissible mA values at 120 and 140 kVp were obtained from the Serial Load Rating table (for mimicking a busy CT clinical operation) in the scanner Technical Reference Manual. At each kVp station and two Noise Index levels, the mA Upper Limit was set above/below the permissible mA values. Scanned mA values and focal spot (FS) used were obtained from the DICOM header of each image, and the FS-mA relationship was analyzed. For visual confirmation beyond recorded FS information, a CatPhan with a fat-ring attached for mimicking patient size/shape was scanned at 120kVp. A group of radiologists/physicists compared a pair of CatPhan images qualitatively. Lastly, a number of patient cases were evaluated to confirm the FS-mA relationship. Results: When preset Upper Limit values were above the permissible mA values, the Large FS (labeled 1.2) was used in scans, even if the maximum scanned mA values were much lower than the permissible values at both 120 and 140 kVp. Otherwise the Small FS (labeled 0.7) was used. Visual evaluation of the high contrast module of CatPhan and additional analysis of patient cases further confirmed that the preset Upper Limit determines which focal spot is to be used, not the actual maximum mA value to be scanned. Conclusion: Specific FS can be selected by setting up appropriate mA Upper Limit in a protocol. CT protocols could be optimized by selecting appropriate FS for improving patient image quality, especially benefiting the small size and pediatric patients.

SU-G-206-08: How Should Focal Spot Be Chosen for Optimized CT Imaging with Dose Modulation?

International Nuclear Information System (INIS)

Bache, S; Liu, X; Rong, J

2016-01-01

Purpose: To choose the preferred focal spot for achieving optimized CT image quality with balanced tube heating considerations. Methods: An anthropomorphic pelvic phantom was scanned using a GE Discovery CT750 HD at 120 and 140kVp, 0.8s rotation time, and pitch of 0.984. “Smart mA” was enabled to simulate a routine abdomen–pelvis CT scan. Permissible mA values at 120 and 140 kVp were obtained from the Serial Load Rating table (for mimicking a busy CT clinical operation) in the scanner Technical Reference Manual. At each kVp station and two Noise Index levels, the mA Upper Limit was set above/below the permissible mA values. Scanned mA values and focal spot (FS) used were obtained from the DICOM header of each image, and the FS-mA relationship was analyzed. For visual confirmation beyond recorded FS information, a CatPhan with a fat-ring attached for mimicking patient size/shape was scanned at 120kVp. A group of radiologists/physicists compared a pair of CatPhan images qualitatively. Lastly, a number of patient cases were evaluated to confirm the FS-mA relationship. Results: When preset Upper Limit values were above the permissible mA values, the Large FS (labeled 1.2) was used in scans, even if the maximum scanned mA values were much lower than the permissible values at both 120 and 140 kVp. Otherwise the Small FS (labeled 0.7) was used. Visual evaluation of the high contrast module of CatPhan and additional analysis of patient cases further confirmed that the preset Upper Limit determines which focal spot is to be used, not the actual maximum mA value to be scanned. Conclusion: Specific FS can be selected by setting up appropriate mA Upper Limit in a protocol. CT protocols could be optimized by selecting appropriate FS for improving patient image quality, especially benefiting the small size and pediatric patients.

Children's (Pediatric) CT (Computed Tomography)

Medline Plus

Full Text Available ... view of the body's interior. Refinements in detector technology allow new CT scanners to obtain multiple slices in a single rotation. These scanners, called "multislice CT" or "multidetector CT," ...

Toward optimal X-ray flux utilization in breast CT

DEFF Research Database (Denmark)

Jørgensen, Jakob Heide; Hansen, Per Christian; Sidky, Emil Y.

2011-01-01

A realistic computer-simulation of a breast computed tomography (CT) system and subject is constructed. The model is used to investigate the optimal number of views for the scan given a fixed total X-ray fluence. The reconstruction algorithm is based on accurate solution to a constrained......, TVminimization problem, which has received much interest recently for sparse-view CT data....

Prognostic value of metabolic indices and bone marrow uptake pattern on preoperative 18F-FDG PET/CT in pediatric patients with neuroblastoma

Energy Technology Data Exchange (ETDEWEB)

Li, Chao; Chen, Suyun; Huang, Shuo; Wu, Shuqi; Zhang, Linlin; Zhang, Fengxian; Wang, Hui [Shanghai Jiao Tong University School of Medicine, Department of Nuclear Medicine, Xinhua Hospital, Shanghai (China); Zhang, Jian [Shanghai Jiao Tong University School of Medicine, Department of Nuclear Medicine, Xinhua Hospital, Shanghai (China); Shanghai Universal Medical Imaging Diagnostic Center, Shanghai (China)

2018-02-15

To evaluate the prognostic value of metabolic parameters and bone marrow uptake (BMU) patterns on pretherapeutic 18-F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in pediatric patients with neuroblastoma (NB). Forty-seven pediatric patients with newly diagnosed neuroblastoma who underwent 18F-FDG PET/CT were retrospectively reviewed. Clinicopathological factors and metabolic parameters including maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG) and bone marrow uptake patterns on PET/CT were compared to predict recurrence-free survival (RFS) and overall survival (OS) by univariate and multivariate analysis. During the follow-up period, 27 (57.4%) patients experienced recurrence. MTV (P = 0.001), TLG (P = 0.004) and BMU patterns (P = 0.025) remained significant predictive factors for tumor recurrence, along with tumor size, histology, stage, lactate dehydrogenase (LDH) and other distant metastasis (except bone metastasis). Univariate analysis showed that histology, stage, tumor size (>37.25 cm), other distant metastasis, MTV (>88.10cm{sup 3}) and TLG (>1045.2 g) and BMU patterns correlated with both RFS and OS (P < 0.05). On multivariate analysis, TLG remained the only independent prognostic factor for RFS (P = 0.016) and OS (P = 0.012), and BMU patterns and MTV were statistically significant for OS (P = 0.024 and P = 0.038, respectively). Pretherapeutic 18F-FDG PET/CT can provide reliable prognostic information for neuroblastoma pediatric patients, and patients with high MTV, TLG and focal bone marrow (unifocal and multifocal) uptake on PET/CT may have inferior outcomes during subsequent treatment. (orig.)

Children's (Pediatric) CT (Computed Tomography)

Medline Plus

Full Text Available ... or nurse at the time of the CT examination. If your child has a known contrast material ... be given to your child for the CT examination. top of page What does the CT equipment ...

Optimization of exposure parameters for pediatric chest x-ray imaging

Science.gov (United States)

Park, Hye-Suk; Kim, Ye-Seul; Kim, Hee-Joung

2012-03-01

The pediatric patients are more susceptible to the effects of ionizing radiation than adults. Pediatric patients are smaller, more radiosensitive than adult patients and many cannot stand unassisted. Their characteristics affect the method of imaging projection and how dose is optimized. The purpose of this study was to investigate the effect of various technical parameters for the dose optimization in pediatric chest radiological examinations by evaluating effective dose and effective detective quantum efficiency (eDQE) including the scatter radiation from the object, the blur caused by the focal spot, geometric magnification and detector characteristics. For the tube voltages ranging from 40 to 90 kV in 10 kV increments at the focus-to-detector distance of 100, 110, 120, 150, 180 cm, the eDQE was evaluated at same effective dose. The results showed that the eDQE was largest at 60 kVp without and with an anti-scatter grid. Especially, the eDQE was considerably higher without the use of an anti-scatter grid on equivalent effective dose. This indicates that the reducing the scatter radiation did not compensate for the loss of absorbed effective photons in the grid. When the grid is not used the eDQE increased with increasing focus-to-detector distance because of the greater effective modulation transfer function (eMTF) with the lower focal spot blurring. In conclusion, for pediatric patients, the amount of scattered radiation is less, and the amount of grid attenuation increased unnecessary radiation dose.

Decreasing the effective radiation dose in pediatric craniofacial CT by changing head position

International Nuclear Information System (INIS)

Didier, Ryne A.; Kuang, Anna A.; Schwartz, Daniel L.; Selden, Nathan R.; Stevens, Donna M.; Bardo, Dianna M.E.

2010-01-01

Children are exposed to ionizing radiation during pre- and post-operative evaluation for craniofacial surgery. The primary purpose of the study was to decrease effective radiation dose while preserving the diagnostic quality of the study. In this prospective study 49 children were positioned during craniofacial CT (CFCT) imaging with their neck fully extended into an exaggerated sniff position, parallel to the CT gantry, to eliminate the majority of the cervical spine and the thyroid gland from radiation exposure. Image-quality and effective radiation dose comparisons were made retrospectively in age-matched controls (n = 49). When compared to CT scans reviewed retrospectively, the prospective examinations showed a statistically significant decrease in z-axis length by 16% (P < 0.0001) and delivered a reduced effective radiation dose by 18% (P < 0.0001). The subjective diagnostic quality of the exams performed in the prospective arm was maintained despite a slight decrease in the quality of the brain windows. There was statistically significant improvement in the quality of the bone windows and three-dimensional reconstructed images. Altering the position of the head by extending the neck during pediatric craniofacial CT imaging statistically reduces the effective radiation dose while maintaining the diagnostic quality of the images. (orig.)

Patient-specific radiation dose and cancer risk for pediatric chest CT.

Science.gov (United States)

Li, Xiang; Samei, Ehsan; Segars, W Paul; Sturgeon, Gregory M; Colsher, James G; Frush, Donald P

2011-06-01

To estimate patient-specific radiation dose and cancer risk for pediatric chest computed tomography (CT) and to evaluate factors affecting dose and risk, including patient size, patient age, and scanning parameters. The institutional review board approved this study and waived informed consent. This study was HIPAA compliant. The study included 30 patients (0-16 years old), for whom full-body computer models were recently created from clinical CT data. A validated Monte Carlo program was used to estimate organ dose from eight chest protocols, representing clinically relevant combinations of bow tie filter, collimation, pitch, and tube potential. Organ dose was used to calculate effective dose and risk index (an index of total cancer incidence risk). The dose and risk estimates before and after normalization by volume-weighted CT dose index (CTDI(vol)) or dose-length product (DLP) were correlated with patient size and age. The effect of each scanning parameter was studied. Organ dose normalized by tube current-time product or CTDI(vol) decreased exponentially with increasing average chest diameter. Effective dose normalized by tube current-time product or DLP decreased exponentially with increasing chest diameter. Chest diameter was a stronger predictor of dose than weight and total scan length. Risk index normalized by tube current-time product or DLP decreased exponentially with both chest diameter and age. When normalized by DLP, effective dose and risk index were independent of collimation, pitch, and tube potential (chest CT protocols. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11101900/-/DC1. RSNA, 2011

Children's (Pediatric) CT (Computed Tomography)

Medline Plus

Full Text Available ... What is Children's CT? What are some common uses of the procedure? How should we prepare for the CT scan? What does the CT equipment look like? How does the procedure work? How is the procedure performed? What will my ...

Children's (Pediatric) CT (Computed Tomography)

Medline Plus

Full Text Available ... CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT ...

Study of dosimetric quantities and image quality in pediatric examinations of chest and abdomen computed tomography

International Nuclear Information System (INIS)

Jornada, Tiago da Silva

2013-01-01

This work had the objective to achieve the knowledge of the dosimetric quantities related to chest and abdomen computed tomography (CT) examinations of pediatric patients, in Belo Horizonte city. The reason of this work is based on the fact that the probability of health detriment in children, which it may be caused by radiation, is higher than in adults. Besides, although in many countries the knowledge and control of patient doses is a normal procedure, this safety culture does not exist in Brazil. Another objective of this work was to compare the dosimetric quantity values with the Diagnostic Reference Levels (DRLs); when it was needed, an optimization process was applied and the quality of the diagnostic image obtained with the optimized technical parameters was analyzed. This study was carried out in five hospitals, where the weighted air kerma index (Cw), the volumetric air kerma index (Cvol), the air kerma - length product (PKL,CT), the Effective Dose (E) and the Normalized Effective Dose (En) were determined; three methods were adopted for measurements: the ionization chamber inside a chest pediatric phantom, radiochromic films and the CT-EXPO software. The optimization process was applied to a single hospital through variations in the current (mA) and voltage (kV) of the x-ray tube for the protocols used for abdomen CT examinations. The analysis of the quality of the diagnostic image was done by Normal Distribution and ROC analysis; spatial resolution analysis was used through MTF determination and the noise level was judged in terms quantitative and qualitative. Results of the dosimetric quantities showed that they significantly differed between single-slice and multi-slice tomography units, but their values were always below the recommended DRLs. The optimized values of the dosimetric quantities obtained after the optimization process showed that it was possible to reduce the radiation exposure of pediatric patient without losing the image quality

A Method for the Automatic Exposure Control in Pediatric Abdominal CT: Application to the Standard Deviation Value and Tube Current Methods by Using Patient's Age and Body Size.

Science.gov (United States)

Furuya, Ken; Akiyama, Shinji; Nambu, Atushi; Suzuki, Yutaka; Hasebe, Yuusuke

2017-01-01

We aimed to apply the pediatric abdominal CT protocol of Donnelly et al. in the United States to the pediatric abdominal CT-AEC. Examining CT images of 100 children, we found that the sectional area of the hepatic portal region (y) was strongly correlated with the body weight (x) as follows: y=7.14x + 84.39 (correlation coefficient=0.9574). We scanned an elliptical cone phantom that simulates the human body using a pediatric abdominal CT scanning method of Donnelly et al. in, and measured SD values. We further scanned the same phantom under the settings for adult CT-AEC scan and obtained the relationship between the sectional areas (y) and the SD values. Using these results, we obtained the following preset noise factors for CT-AEC at each body weight range: 6.90 at 4.5-8.9 kg, 8.40 at 9.0-17.9 kg, 8.68 at 18.0-26.9 kg, 9.89 at 27.0-35.9 kg, 12.22 at 36.0-45.0 kg, 13.52 at 45.1-70.0 kg, 15.29 at more than 70 kg. From the relation between age, weight and the distance of liver and tuber ischiadicum of 500 children, we obtained the CTDI vol values and DLP values under the scanning protocol of Donnelly et al. Almost all of DRL from these values turned out to be smaller than the DRL data of IAEA and various countries. Thus, by setting the maximum current values of CT-AEC to be the Donnelly et al.'s age-wise current values, and using our weight-wise noise factors, we think we can perform pediatric abdominal CT-AEC scans that are consistent with the same radiation safety and the image quality as those proposed by Donnelly et al.

{sup 18}F-FDG PET/CT compared to conventional imaging modalities in pediatric primary bone tumors

Energy Technology Data Exchange (ETDEWEB)

London, Kevin [The Children' s Hospital at Westmead, Department of Nuclear Medicine, Sydney, NSW (Australia); University of Sydney, Discipline of Paediatrics and Child Health, Sydney Medical School, Sydney, NSW (Australia); Stege, Claudia; Kaspers, Gertjan [VU Medical Centre, Divisions of Paediatric Oncology/Haematology, Amsterdam (Netherlands); Cross, Siobhan; Dalla-Pozza, Luciano [The Children' s Hospital at Westmead, Department of Oncology, Sydney (Australia); Onikul, Ella [The Children' s Hospital at Westmead, Department of Medical Imaging, Sydney (Australia); Graf, Nicole [The Children' s Hospital at Westmead, Department of Pathology, Sydney (Australia); Howman-Giles, Robert [The Children' s Hospital at Westmead, Department of Nuclear Medicine, Sydney, NSW (Australia); University of Sydney, Discipline of Imaging, Sydney Medical School, Sydney, NSW (Australia)

2012-04-15

F-Fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) is useful in adults with primary bone tumors. Limited published data exist in children. To compare hybrid FDG positron emission tomography/computed tomography (PET/CT) with conventional imaging (CI) modalities in detecting malignant lesions, predicting response to chemotherapy and diagnosing physeal involvement in pediatric primary bone tumors. Retrospective analysis of PET/CT and CI reports with histopathology or follow-up > 6 months as reference standard. Response parameters and physeal involvement at diagnosis were compared to histopathology. A total of 314 lesions were detected in 86 scans. Excluding lung lesions, PET/CT had higher sensitivity and specificity than CI (83%, 98% and 78%, 97%, respectively). In lung lesions, PET/CT had higher specificity than CI (96% compared to 87%) but lower sensitivity (80% compared to 93%). Higher initial SUV{sub max} and greater SUV{sub max} reduction on PET/CT after chemotherapy predicted a good response. Change in tumor size on MRI did not predict response. Both PET/CT and MRI were very sensitive but of low specificity in predicting physeal tumor involvement. PET/CT appears more accurate than CI in detecting malignant lesions in childhood primary bone tumors, excluding lung lesions. It seems better than MRI at predicting tumor response to chemotherapy. (orig.)

Children's (Pediatric) CT (Computed Tomography)

Medline Plus

Full Text Available ... vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT is less sensitive to patient movement ...

Children's (Pediatric) CT (Computed Tomography)

Medline Plus

Full Text Available ... multislice CT" or "multidetector CT," allow thinner slices to be obtained, resulting in more detail of the body, in a shorter period of time. Modern CT scanners are so fast that they can scan through large sections of the body in just a few seconds. Such speed is beneficial for ...

Pediatric AIDS

International Nuclear Information System (INIS)

Price, D.B.; Haller, J.O.; Kramer, J.; Hotson, G.C.; Loh, J.P.; Schlusselberg, D.; Inglese, C.M.; Jacobs, J.; Rose, A.L.; Menez-Bautista, R.; Fikrig, S.

1988-01-01

A group of 23 pediatric patients seropositive for HIV antibody were studied by computed tomography and evaluated neurodevelopmentally. Significant neurodevelopmental delays were found in over 95% of the patients studied. CT findings in six patients were normal and thirteen of 23 (57%) had prominence of the CSF spaces. Less frequent findings included calcifications in the basal ganglia and white matter. Cerebral mass lesions included one case of lymphoma and one case of hemorrhage. The CT findings in the pediatric age group differs from the adult population in that that contrast enhancing inflammatory mass lesions are uncommon. (orig.)

MO-E-17A-09: Has Cancer Risk for Pediatric CT Increased Or Decreased? An Analysis of Cohort Data From 2004-2013

International Nuclear Information System (INIS)

Brady, S; Kaufman, R

2014-01-01

Purpose: To analyze CT radiation dosimetry trends in a pediatric population imaged with modern (2004-2013) CT technology Methods: The institutional review board approved this retrospective review. Two cohorts of pediatric patients that received CT scans for treatment or surveillance for Wilms tumor (n=73) or Neuroblastoma (n=74) from 2004–2013 were included in this study. Patients were scanned during this time period on a GE Ultra (8 slice; 2004–2007), a GE VCT (2008–2011), or a GE VCT-XTe (2011–2013). Each patient's individual or combined chest, abdomen, and pelvic CT exams (n=4138) were loaded onto a PACS workstation (Intelerad, Canada) and measured to calculate their effective diameter and SSDE. Patient SSDE was used to estimate patient organ dosimetry based on previously published data. Patient's organ dosimetry were sorted by gender, weight, age, scan protocol (i.e., chest, abdomen, or pelvis), and CT scanner technology and averaged accordingly to calculate population averaged absolute and effective dose values. Results: Patient radiation dose burden calculated for all genders, weights, and ages decreased at a rate of 0.2 mSv/year (4.2 mGy/year; average organ dose) from 2004–2013; overall levels decreased by 50% from 3.0 mSv (60.0 mGy) to 1.5 mSv (25.9 mGy). Patient dose decreased at equal rates for both male and female, and for individual scan protocols. The greatest dose savings was found for patients between 0–4 years old (65%) followed by 5-9 years old (45%), 10–14 years old (30%), and > 14 years old (21%). Conclusion: Assuming a linear-nothreshold model, there always will be potential risk of cancer induction from CT. However, as demonstrated among these patient populations, effective and organ dose has decreased over the last decade; thus, potential risk of long-term side effects from pediatric CT examinations has also been reduced

MO-E-17A-09: Has Cancer Risk for Pediatric CT Increased Or Decreased? An Analysis of Cohort Data From 2004-2013

Energy Technology Data Exchange (ETDEWEB)

Brady, S; Kaufman, R [St. Jude Children' s Research Hospital, Memphis, TN (United States)

2014-06-15

Purpose: To analyze CT radiation dosimetry trends in a pediatric population imaged with modern (2004-2013) CT technology Methods: The institutional review board approved this retrospective review. Two cohorts of pediatric patients that received CT scans for treatment or surveillance for Wilms tumor (n=73) or Neuroblastoma (n=74) from 2004–2013 were included in this study. Patients were scanned during this time period on a GE Ultra (8 slice; 2004–2007), a GE VCT (2008–2011), or a GE VCT-XTe (2011–2013). Each patient's individual or combined chest, abdomen, and pelvic CT exams (n=4138) were loaded onto a PACS workstation (Intelerad, Canada) and measured to calculate their effective diameter and SSDE. Patient SSDE was used to estimate patient organ dosimetry based on previously published data. Patient's organ dosimetry were sorted by gender, weight, age, scan protocol (i.e., chest, abdomen, or pelvis), and CT scanner technology and averaged accordingly to calculate population averaged absolute and effective dose values. Results: Patient radiation dose burden calculated for all genders, weights, and ages decreased at a rate of 0.2 mSv/year (4.2 mGy/year; average organ dose) from 2004–2013; overall levels decreased by 50% from 3.0 mSv (60.0 mGy) to 1.5 mSv (25.9 mGy). Patient dose decreased at equal rates for both male and female, and for individual scan protocols. The greatest dose savings was found for patients between 0–4 years old (65%) followed by 5-9 years old (45%), 10–14 years old (30%), and > 14 years old (21%). Conclusion: Assuming a linear-nothreshold model, there always will be potential risk of cancer induction from CT. However, as demonstrated among these patient populations, effective and organ dose has decreased over the last decade; thus, potential risk of long-term side effects from pediatric CT examinations has also been reduced.

Ultralow dose computed tomography attenuation correction for pediatric PET CT using adaptive statistical iterative reconstruction

International Nuclear Information System (INIS)

Brady, Samuel L.; Shulkin, Barry L.

2015-01-01

Purpose: To develop ultralow dose computed tomography (CT) attenuation correction (CTAC) acquisition protocols for pediatric positron emission tomography CT (PET CT). Methods: A GE Discovery 690 PET CT hybrid scanner was used to investigate the change to quantitative PET and CT measurements when operated at ultralow doses (10–35 mA s). CT quantitation: noise, low-contrast resolution, and CT numbers for 11 tissue substitutes were analyzed in-phantom. CT quantitation was analyzed to a reduction of 90% volume computed tomography dose index (0.39/3.64; mGy) from baseline. To minimize noise infiltration, 100% adaptive statistical iterative reconstruction (ASiR) was used for CT reconstruction. PET images were reconstructed with the lower-dose CTAC iterations and analyzed for: maximum body weight standardized uptake value (SUV bw ) of various diameter targets (range 8–37 mm), background uniformity, and spatial resolution. Radiation dose and CTAC noise magnitude were compared for 140 patient examinations (76 post-ASiR implementation) to determine relative dose reduction and noise control. Results: CT numbers were constant to within 10% from the nondose reduced CTAC image for 90% dose reduction. No change in SUV bw , background percent uniformity, or spatial resolution for PET images reconstructed with CTAC protocols was found down to 90% dose reduction. Patient population effective dose analysis demonstrated relative CTAC dose reductions between 62% and 86% (3.2/8.3–0.9/6.2). Noise magnitude in dose-reduced patient images increased but was not statistically different from predose-reduced patient images. Conclusions: Using ASiR allowed for aggressive reduction in CT dose with no change in PET reconstructed images while maintaining sufficient image quality for colocalization of hybrid CT anatomy and PET radioisotope uptake

Ultralow dose computed tomography attenuation correction for pediatric PET CT using adaptive statistical iterative reconstruction

Energy Technology Data Exchange (ETDEWEB)

Brady, Samuel L., E-mail: samuel.brady@stjude.org [Division of Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105 (United States); Shulkin, Barry L. [Nuclear Medicine and Department of Radiological Sciences, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105 (United States)

2015-02-15

Purpose: To develop ultralow dose computed tomography (CT) attenuation correction (CTAC) acquisition protocols for pediatric positron emission tomography CT (PET CT). Methods: A GE Discovery 690 PET CT hybrid scanner was used to investigate the change to quantitative PET and CT measurements when operated at ultralow doses (10–35 mA s). CT quantitation: noise, low-contrast resolution, and CT numbers for 11 tissue substitutes were analyzed in-phantom. CT quantitation was analyzed to a reduction of 90% volume computed tomography dose index (0.39/3.64; mGy) from baseline. To minimize noise infiltration, 100% adaptive statistical iterative reconstruction (ASiR) was used for CT reconstruction. PET images were reconstructed with the lower-dose CTAC iterations and analyzed for: maximum body weight standardized uptake value (SUV{sub bw}) of various diameter targets (range 8–37 mm), background uniformity, and spatial resolution. Radiation dose and CTAC noise magnitude were compared for 140 patient examinations (76 post-ASiR implementation) to determine relative dose reduction and noise control. Results: CT numbers were constant to within 10% from the nondose reduced CTAC image for 90% dose reduction. No change in SUV{sub bw}, background percent uniformity, or spatial resolution for PET images reconstructed with CTAC protocols was found down to 90% dose reduction. Patient population effective dose analysis demonstrated relative CTAC dose reductions between 62% and 86% (3.2/8.3–0.9/6.2). Noise magnitude in dose-reduced patient images increased but was not statistically different from predose-reduced patient images. Conclusions: Using ASiR allowed for aggressive reduction in CT dose with no change in PET reconstructed images while maintaining sufficient image quality for colocalization of hybrid CT anatomy and PET radioisotope uptake.

Quality of pediatric abdominal CT scans performed at a dedicated children's hospital and its referring institutions: a multifactorial evaluation

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Snow, Aisling [Boston Children' s Hospital, Department of Radiology, Boston, MA (United States); Our Lady' s Children' s Hospital, Department of Radiology, Dublin (Ireland); Milliren, Carly E.; Graham, Dionne A. [Boston Children' s Hospital, Program for Patient Safety and Quality, Boston, MA (United States); Callahan, Michael J.; MacDougall, Robert D.; Robertson, Richard L.; Taylor, George A. [Boston Children' s Hospital, Department of Radiology, Boston, MA (United States)

2017-04-15

Pediatric patients requiring transfer to a dedicated children's hospital from an outside institution may undergo CT imaging as part of their evaluation. Whether this imaging is performed prior to or after transfer has been shown to impact the radiation dose imparted to the patient. Other quality variables could also be affected by the pediatric experience and expertise of the scanning institution. To identify differences in quality between abdominal CT scans and reports performed at a dedicated children's hospital, and those performed at referring institutions. Fifty consecutive pediatric abdominal CT scans performed at outside institutions were matched (for age, gender and indication) with 50 CT scans performed at a dedicated freestanding children's hospital. We analyzed the scans for technical parameters, report findings, correlation with final clinical diagnosis, and clinical utility. Technical evaluation included use of intravenous and oral contrast agents, anatomical coverage, number of scan phases and size-specific dose estimate (SSDE) for each scan. Outside institution scans were re-reported when the child was admitted to the children's hospital; they were also re-interpreted for this study by children's hospital radiologists who were provided with only the referral information given in the outside institution's report. Anonymized original outside institutional reports and children's hospital admission re-reports were analyzed by two emergency medicine physicians for ease of understanding, degree to which the clinical question was answered, and level of confidence in the report. Mean SSDE was lower (8.68) for children's hospital scans, as compared to outside institution scans (13.29, P = 0.03). Concordance with final clinical diagnosis was significantly lower for original outside institution reports (38/48, 79%) than for both the admission and study children's hospital reports (48/50, 96%; P = 0.005). Children

MRI imaging in pediatric appendicitis

Directory of Open Access Journals (Sweden)

Robin Riley

2018-04-01

Full Text Available An 8-year-old male presents with two days of abdominal pain and emesis. Computed tomography was concerning for obstruction or reactive ileus with an apparent transition point in the right lower quadrant, possibly due to Crohn's. Magnetic resonance imaging was concerning for perforated appendicitis. As demonstrated by this case MRI can be as sensitive as CT in detecting pediatric appendicitis [2]. We recommend using MRI instead of CT to diagnose appendicitis to avoid ionizing radiation and increased cancer risk in the pediatric population. Keywords: Computer tomography, Magnetic resonance imaging, Pediatric appendicitis

Computed Tomography (CT) -- Sinuses

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Full Text Available ... tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

Computed Tomography (CT) -- Head

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Full Text Available ... tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

Abdominal and Pelvic CT

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Full Text Available ... tomography (CT) scan View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

Evaluation of X ray radiation doses in pediatric examinations of cranial computerized tomography based on optimization studies; Avaliacao das doses de radiacao X em exames pediatricos de tomografia computadorizada de cranio com base em estudos de otimizacao

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Daros, Kellen Adriana Curci

2005-07-01

This paper identifies the technical conditions for CT examination which offers lowest absorbed dose and to attend the manufacturer recommendations as far the spatial resolution is concerned. The paper evaluates the absorbed dose during cranial CT in up to 6 years children satisfying the technical condition recommended by the manufacturer and routine clinical conditions. The paper also established a quantitative relationship among the absorbed dose and its distribution in the cranial regions of pediatric patients up to 6 years old in a way to estimate the doses subject to optimized conditions

Pediatric Nephrolithiasis: A Review.

Science.gov (United States)

Miah, Tayaba; Kamat, Deepak

2017-06-01

The incidence of pediatric nephrolithiasis is on the rise. The composition of kidney stones in children is different than in adults, as most stones in children have a composition of calcium oxalate and calcium phosphate mixed with a small amount of uric acid. The symptoms of pediatric nephrolithiasis are nonspecific. Computed tomography (CT) is the gold standard for diagnosis; however, because of radiation exposure associated with a CT scan, ultrasonography is also an accepted modality for the diagnosis. Extensive metabolic evaluation is important to rule out an underlying metabolic disorder. Urinary decompression, medical expulsion therapy, and surgical interventions such as ureteroscopy and extracorporeal shockwave lithotripsy are some of the options available for treating pediatric nephrolithiasis. [Pediatr Ann. 2017;46(6):e242-e244.]. Copyright 2017, SLACK Incorporated.

Thermoluminescent dosimetry in computed tomography for pediatric patients

International Nuclear Information System (INIS)

Medrano S, A. C.; Medina A, O.; Hidalgo T, S.; Azorin N, J.

2015-10-01

Computed tomography (CT) in conjunction with interventional radiology, is considered as high-dose radiological procedure, so the optimization of the dose is necessary. Exposure to ionizing radiation in pediatric CT is of particular interest because the children are up to 10 times more sensitive to radiation than adults, the late somatic and genetic effects of radiation. The exposure and risk associated with ionizing radiation in CT is best characterized by the absorbed dose to each organ. Thermoluminescent dosimeters of LiF: Mg, Ti are best suited for this purpose due to its characteristics such as high sensitivity, small size and its equivalence with the tissue. The results of dose measurements -in vivo- to the three types of CT studies (skull, thorax and abdomen) are presented. These results indicate that lower doses were obtained in skull study, while the highest was one of abdomen. (Author)

Survey of pediatric MDCT radiation dose from university hospitals in Thailand. A preliminary for national dose survey

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Kritsaneepaiboon, Supika [Dept. of Radiology, Faculty of Medicine, Prince of Songkla Univ., Hat Yai (Thailand)], e-mail: supikak@yahoo.com; Trinavarat, Panruethai [Dept. of Radiology, Faculty of Medicine, Chulalongkorn Univ., Bangkok (Thailand); Visrutaratna, Pannee [Dept. of Radiology, Faculty of Medicine, Chiang Mai Univ., Chiang Mai (Thailand)

2012-09-15

Background: Increasing pediatric CT usage worldwide needs the optimization of CT protocol examination. Although there are previous published dose reference level (DRL) values, the local DRLs should be established to guide for clinical practice and monitor the CT radiation. Purpose: To determine the multidetector CT (MDCT) radiation dose in children in three university hospitals in Thailand in four age groups using the CT dose index (CTDI) and dose length product (DLP). Material and Methods: A retrospective review of CT dosimetry in pediatric patients (<15 years of age) who had undergone head, chest, and abdominal MDCT in three major university hospitals in Thailand was performed. Volume CTDI (CTDIvol) and DLP were recorded, categorized into four age groups: <1 year, 1- < 5 years, 5- <10 years, and 10- <15 years in each scanner. Range, mean, and third quartile values were compared with the national reference dose levels for CT in pediatric patients from the UK and Switzerland according to International Commission on Radiological Protection (ICRP) recommendation. Results: Per age group, the third quartile values for brain, chest, and abdominal CTs were, respectively, in terms of CTDIvol: 25, 30, 40, and 45 mGy; 4.5, 5.7, 10, and 15.6 mGy; 8.5, 9, 14, and 17 mGy; and in terms of DLP: 400, 570, 610, and 800 mGy cm; 80, 140, 305, and 470 mGy cm; and 190, 275, 560,765 mGy cm. Conclusion: This preliminary national dose survey for pediatric CT in Thailand found that the majority of CTDIvol and DLP values in brain, chest, and abdominal CTs were still below the diagnostic reference levels (DRLs) from the UK and Switzerland regarding to ICRP recommendation.

Pediatric CT Scans

Science.gov (United States)

The Radiation Epidemiology Branch and collaborators have initiated a retrospective cohort study to evaluate the relationship between radiation exposure from CT scans conducted during childhood and adolescence and the subsequent development of cancer.

Radiologic head CT interpretation errors in pediatric abusive and non-abusive head trauma patients

International Nuclear Information System (INIS)

Kralik, Stephen F.; Finke, Whitney; Wu, Isaac C.; Ho, Chang Y.; Hibbard, Roberta A.; Hicks, Ralph A.

2017-01-01

Pediatric head trauma, including abusive head trauma, is a significant cause of morbidity and mortality. The purpose of this research was to identify and evaluate radiologic interpretation errors of head CTs performed on abusive and non-abusive pediatric head trauma patients from a community setting referred for a secondary interpretation at a tertiary pediatric hospital. A retrospective search identified 184 patients <5 years of age with head CT for known or potential head trauma who had a primary interpretation performed at a referring community hospital by a board-certified radiologist. Two board-certified fellowship-trained neuroradiologists at an academic pediatric hospital independently interpreted the head CTs, compared their interpretations to determine inter-reader discrepancy rates, and resolved discrepancies to establish a consensus second interpretation. The primary interpretation was compared to the consensus second interpretation using the RADPEER trademark scoring system to determine the primary interpretation-second interpretation overall and major discrepancy rates. MRI and/or surgical findings were used to validate the primary interpretation or second interpretation when possible. The diagnosis of abusive head trauma was made using clinical and imaging data by a child abuse specialist to separate patients into abusive head trauma and non-abusive head trauma groups. Discrepancy rates were compared for both groups. Lastly, primary interpretations and second interpretations were evaluated for discussion of imaging findings concerning for abusive head trauma. There were statistically significant differences between primary interpretation-second interpretation versus inter-reader overall and major discrepancy rates (28% vs. 6%, P=0.0001; 16% vs. 1%, P=0.0001). There were significant differences in the primary interpretation-second interpretation overall and major discrepancy rates for abusive head trauma patients compared to non-abusive head trauma

Radiologic head CT interpretation errors in pediatric abusive and non-abusive head trauma patients

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Kralik, Stephen F.; Finke, Whitney; Wu, Isaac C.; Ho, Chang Y. [Indiana University School of Medicine, Department of Radiology and Imaging Sciences, Indianapolis, IN (United States); Hibbard, Roberta A.; Hicks, Ralph A. [Indiana University School of Medicine, Department of Pediatrics, Section of Child Protection Programs, Indianapolis, IN (United States)

2017-07-15

Pediatric head trauma, including abusive head trauma, is a significant cause of morbidity and mortality. The purpose of this research was to identify and evaluate radiologic interpretation errors of head CTs performed on abusive and non-abusive pediatric head trauma patients from a community setting referred for a secondary interpretation at a tertiary pediatric hospital. A retrospective search identified 184 patients <5 years of age with head CT for known or potential head trauma who had a primary interpretation performed at a referring community hospital by a board-certified radiologist. Two board-certified fellowship-trained neuroradiologists at an academic pediatric hospital independently interpreted the head CTs, compared their interpretations to determine inter-reader discrepancy rates, and resolved discrepancies to establish a consensus second interpretation. The primary interpretation was compared to the consensus second interpretation using the RADPEER trademark scoring system to determine the primary interpretation-second interpretation overall and major discrepancy rates. MRI and/or surgical findings were used to validate the primary interpretation or second interpretation when possible. The diagnosis of abusive head trauma was made using clinical and imaging data by a child abuse specialist to separate patients into abusive head trauma and non-abusive head trauma groups. Discrepancy rates were compared for both groups. Lastly, primary interpretations and second interpretations were evaluated for discussion of imaging findings concerning for abusive head trauma. There were statistically significant differences between primary interpretation-second interpretation versus inter-reader overall and major discrepancy rates (28% vs. 6%, P=0.0001; 16% vs. 1%, P=0.0001). There were significant differences in the primary interpretation-second interpretation overall and major discrepancy rates for abusive head trauma patients compared to non-abusive head trauma

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... CT is well-suited for visualizing diseases or injury of important organs in the abdomen including the liver, kidney and spleen. CT is sometimes used to: diagnose appendicitis detect ...

Computed Tomography (CT) -- Sinuses

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Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses Computed tomography (CT) of the sinuses uses special x-ray equipment ... story here Images × Image Gallery Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content ...

Computed Tomography (CT) -- Head

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Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special x-ray equipment ... story here Images × Image Gallery Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content ...

Pediatric cT: Implementation of ASIR for Substantial Radiation Dose Reduction While Maintaining Pre-ASIR Image Noise1

Science.gov (United States)

Brady, Samuel L.; Moore, Bria M.; Yee, Brian S.; Kaufman, Robert A.

2015-01-01

Purpose To determine a comprehensive method for the implementation of adaptive statistical iterative reconstruction (ASIR) for maximal radiation dose reduction in pediatric computed tomography (CT) without changing the magnitude of noise in the reconstructed image or the contrast-to-noise ratio (CNR) in the patient. Materials and Methods The institutional review board waived the need to obtain informed consent for this HIPAA-compliant quality analysis. Chest and abdominopelvic CT images obtained before ASIR implementation (183 patient examinations; mean patient age, 8.8 years ± 6.2 [standard deviation]; range, 1 month to 27 years) were analyzed for image noise and CNR. These measurements were used in conjunction with noise models derived from anthropomorphic phantoms to establish new beam current–modulated CT parameters to implement 40% ASIR at 120 and 100 kVp without changing noise texture or magnitude. Image noise was assessed in images obtained after ASIR implementation (492 patient examinations; mean patient age, 7.6 years ± 5.4; range, 2 months to 28 years) the same way it was assessed in the pre-ASIR analysis. Dose reduction was determined by comparing size-specific dose estimates in the pre- and post-ASIR patient cohorts. Data were analyzed with paired t tests. Results With 40% ASIR implementation, the average relative dose reduction for chest CT was 39% (2.7/4.4 mGy), with a maximum reduction of 72% (5.3/18.8 mGy). The average relative dose reduction for abdominopelvic CT was 29% (4.8/6.8 mGy), with a maximum reduction of 64% (7.6/20.9 mGy). Beam current modulation was unnecessary for patients weighing 40 kg or less. The difference between 0% and 40% ASIR noise magnitude was less than 1 HU, with statistically nonsignificant increases in patient CNR at 100 kVp of 8% (15.3/14.2; P = .41) for chest CT and 13% (7.8/6.8; P = .40) for abdominopelvic CT. Conclusion Radiation dose reduction at pediatric CT was achieved when 40% ASIR was implemented as a dose

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... obtain CT images. It is known that high levels of radiation may cause cancer. However, CT scans result in a low-level exposure. Whether such levels cause cancer is debatable ...

Realistic phantoms to characterize dosimetry in pediatric CT

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Carver, Diana E.; Kost, Susan D.; Fraser, Nicholas D.; Pickens, David R.; Price, Ronald R.; Stabin, Michael G. [Vanderbilt University Medical Center, Department of Radiology and Radiological Sciences, Nashville, TN (United States); Segars, W.P. [Duke University, Carl E. Ravin Advanced Imaging Laboratories, Durham, NC (United States)

2017-05-15

The estimation of organ doses and effective doses for children receiving CT examinations is of high interest. Newer, more realistic anthropomorphic body models can provide information on individual organ doses and improved estimates of effective dose. Previously developed body models representing 50th-percentile individuals at reference ages (newborn, 1, 5, 10 and 15 years) were modified to represent 10th, 25th, 75th and 90th height percentiles for both genders and an expanded range of ages (3, 8 and 13 years). We calculated doses for 80 pediatric reference phantoms from simulated chest-abdomen-pelvis exams on a model of a Philips Brilliance 64 CT scanner. Individual organ and effective doses were normalized to dose-length product (DLP) and fit as a function of body diameter. We calculated organ and effective doses for 80 reference phantoms and plotted them against body diameter. The data were well fit with an exponential function. We found DLP-normalized organ dose to correlate strongly with body diameter (R{sup 2}>0.95 for most organs). Similarly, we found a very strong correlation with body diameter for DLP-normalized effective dose (R{sup 2}>0.99). Our results were compared to other studies and we found average agreement of approximately 10%. We provide organ and effective doses for a total of 80 reference phantoms representing normal-stature children ranging in age and body size. This information will be valuable in replacing the types of vendor-reported doses available. These data will also permit the recording and tracking of individual patient doses. Moreover, this comprehensive dose database will facilitate patient matching and the ability to predict patient-individualized dose prior to examination. (orig.)

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... top of page What are the benefits vs. risks? Benefits Using a multidetector CT unit to examine ... CT scans should have no immediate side effects. Risks The risk of serious allergic reaction to contrast ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... vessels. CT scans may be performed on newborns, infants and older children. top of page What are ... heart and blood vessels in children, even newborn infants. Except for the chest x-ray, CT is ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... trauma to blood vessels or lung CT is well-suited for visualizing diseases or injury of important ... detailed images of many types of tissue as well as the lungs, bones, and blood vessels. CT ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... scanner. top of page How does the procedure work? In many ways, CT scanning is like other ... accurate. A major advantage of CT is its ability to image bone, soft tissue and blood vessels ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... outside of the CT scanner itself is very low. If you suspect you may be pregnant, however, ... cause cancer. However, CT scans result in a low-level exposure. Whether such levels cause cancer is ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called "multislice CT" or "multidetector CT," ... prescribed procedure with your doctor, the medical facility staff and/or your insurance provider to get a ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT ... be performed to evaluate blood vessels throughout the body. With CT, it is possible to obtain very ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... a very detailed multidimensional view of the body's interior. Refinements in detector technology allow new CT scanners ... to read. top of page What will my child experience during and after the procedure? CT exams ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... as a CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces ... of imaging in these procedures in children. A diagnosis determined by CT scanning may eliminate the need ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... with the CT technologist or nurse at the time of the CT examination. If your child has ... detectors rotate around the patient. At the same time, the examination table is moving through the scanner, ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... such as inflammation of the bronchi (breathing passages) birth defects trauma to blood vessels or lung CT ... used to: diagnose appendicitis detect abdominal tumors or birth defects In the pelvic region, CT scans can ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... medications and allergies. Inform your doctor and the technologist prior to the exam if your child has ... exam. This can be discussed with the CT technologist, the specialist who will be performing the CT ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... is Children's CT? Computed tomography, more commonly known as a CT or CAT scan, is a diagnostic ... is used to evaluate: complications from infections such as pneumonia a tumor that arises in the lung ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called "multislice CT" or "multidetector CT," ... best for your child. top of page Additional Information and Resources The Alliance for Radiation Safety in ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... also be discussed with the CT technologist or nurse at the time of the CT examination. If ... difficulty breathing, you should notify the technologist or nurse, as it may indicate a more severe allergic ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... scanner. top of page How does the procedure work? In many ways, CT scanning is like other ... scanning is painless, noninvasive and accurate. A major advantage of CT is its ability to image bone, ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Using a multidetector CT unit to examine children ... scanning is painless, noninvasive and accurate. A major advantage of CT is its ability to image bone, ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Using a multidetector CT unit to examine children ... unlike MRI. CT imaging provides real-time imaging, making it a good tool for guiding minimally invasive ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... many ways, CT scanning is like other x-ray examinations. X-rays are a form of radiation, like light ... denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams Contrast Materials Anesthesia Safety ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... of page What are the benefits vs. risks? Benefits Using a multidetector CT unit to examine children is faster than the older CT scanners, reducing the need for sedation and general anesthesia. New technologies that will make even faster scanning possible ...

Cost-effective pediatric head and body phantoms for computed tomography dosimetry and its evaluation using pencil ion chamber and CT dose profiler

Directory of Open Access Journals (Sweden)

A Saravanakumar

2015-01-01

Full Text Available In the present work, a pediatric head and body phantom was fabricated using polymethyl methacrylate (PMMA at a low cost when compared to commercially available phantoms for the purpose of computed tomography (CT dosimetry. The dimensions of head and body phantoms were 10 cm diameter, 15 cm length and 16 cm diameter, 15 cm length, respectively. The dose from a 128-slice CT machine received by the head and body phantom at the center and periphery were measured using a 100 mm pencil ion chamber and 150 mm CT dose profiler (CTDP. Using these values, the weighted computed tomography dose index (CTDIw and in turn the volumetric CTDI (CTDIv were calculated for various combinations of tube voltage and current-time product. A similar study was carried out using standard calibrated phantom and the results have been compared with the fabricated ones to ascertain that the performance of the latter is equivalent to that of the former. Finally, CTDIv measured using fabricated and standard phantoms were compared with respective values displayed on the console. The difference between the values was well within the limits specified by Atomic Energy Regulatory Board (AERB, India. These results indicate that the cost-effective pediatric phantom can be employed for CT dosimetry.

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... top of page What are the benefits vs. risks? Benefits Using a multidetector CT unit to examine children is faster than the older CT scanners, reducing the need for sedation and general anesthesia. New technologies that will make even faster scanning possible are ...

SU-F-J-214: Dose Reduction by Spatially Optimized Image Quality Via Fluence Modulated Proton CT (FMpCT)

International Nuclear Information System (INIS)

De Angelis, L; Landry, G; Dedes, G; Parodi, K; Hansen, D; Rit, S; Belka, C

2016-01-01

Purpose: Proton CT (pCT) is a promising imaging modality for reducing range uncertainty in image-guided proton therapy. Range uncertainties partially originate from X-ray CT number conversion to stopping power ratio (SPR) and are limiting the exploitation of the full potential of proton therapy. In this study we explore the concept of spatially dependent fluence modulated proton CT (FMpCT), for achieving optimal image quality in a clinical region of interest (ROI), while reducing significantly the imaging dose to the patient. Methods: The study was based on simulated ideal pCT using pencil beam (PB) scanning. A set of 250 MeV protons PBs was used to create 360 projections of a cylindrical water phantom and a head and neck cancer patient. The tomographic images were reconstructed using a filtered backprojection (FBP) as well as an iterative algorithm (ITR). Different fluence modulation levels were investigated and their impact on the image was quantified in terms of SPR accuracy as well as noise within and outside selected ROIs, as a function of imaging dose. The unmodulated image served as reference. Results: Both FBP reconstruction and ITR without total variation (TV) yielded image quality in the ROIs similar to the reference images, for modulation down to 0.1 of the full proton fluence. The average dose was reduced by 75% for the water phantom and by 40% for the patient. FMpCT does not improve the noise for ITR with TV and modulation 0.1. Conclusion: This is the first work proposing and investigating FMpCT for producing optimal image quality for treatment planning and image guidance, while simultaneously reducing imaging dose. Future work will address spatial resolution effects and the impact of FMpCT on the quality of proton treatment plans for a prototype pCT scanner capable of list mode data acquisition. Acknowledgement: DFG-MAP DFG - Munich-Centre for Advanced Photonics (MAP)

SU-F-J-214: Dose Reduction by Spatially Optimized Image Quality Via Fluence Modulated Proton CT (FMpCT)

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De Angelis, L; Landry, G; Dedes, G; Parodi, K [Ludwig-Maximilians-Universitaet Muenchen (LMU Munich), Garching b. Muenchen (Germany); Hansen, D [Aarhus University Hospital, Aarhus, Jutland (Denmark); Rit, S [University Lyon, Lyon, Auvergne-Rhone-Alpes (France); Belka, C [LMU Munich, Munich (Germany)

2016-06-15

Purpose: Proton CT (pCT) is a promising imaging modality for reducing range uncertainty in image-guided proton therapy. Range uncertainties partially originate from X-ray CT number conversion to stopping power ratio (SPR) and are limiting the exploitation of the full potential of proton therapy. In this study we explore the concept of spatially dependent fluence modulated proton CT (FMpCT), for achieving optimal image quality in a clinical region of interest (ROI), while reducing significantly the imaging dose to the patient. Methods: The study was based on simulated ideal pCT using pencil beam (PB) scanning. A set of 250 MeV protons PBs was used to create 360 projections of a cylindrical water phantom and a head and neck cancer patient. The tomographic images were reconstructed using a filtered backprojection (FBP) as well as an iterative algorithm (ITR). Different fluence modulation levels were investigated and their impact on the image was quantified in terms of SPR accuracy as well as noise within and outside selected ROIs, as a function of imaging dose. The unmodulated image served as reference. Results: Both FBP reconstruction and ITR without total variation (TV) yielded image quality in the ROIs similar to the reference images, for modulation down to 0.1 of the full proton fluence. The average dose was reduced by 75% for the water phantom and by 40% for the patient. FMpCT does not improve the noise for ITR with TV and modulation 0.1. Conclusion: This is the first work proposing and investigating FMpCT for producing optimal image quality for treatment planning and image guidance, while simultaneously reducing imaging dose. Future work will address spatial resolution effects and the impact of FMpCT on the quality of proton treatment plans for a prototype pCT scanner capable of list mode data acquisition. Acknowledgement: DFG-MAP DFG - Munich-Centre for Advanced Photonics (MAP)

Assessment of Regional Pediatric Computed Tomography Dose Indices in Tamil Nadu.

Science.gov (United States)

Saravanakumar, A; Vaideki, K; Govindarajan, K N; Jayakumar, S; Devanand, B

2017-01-01

The aim of this article is to assess Tamil Nadu pediatric computed tomography (CT) diagnostic reference levels (DRLs) by collecting radiation dose data for the most commonly performed CT examinations. This work was performed for thirty CT scanners installed in various parts of the Tamil Nadu region. The patient cohort was divided into two age groups: <1 year, and 1-5 years. CT dose indices were measured using a 10 cm 3 pencil ion chamber with pediatric head and body polymethyl methacrylate phantoms. Dose data such as volumetric CT dose index (CTDI v ) and dose length product (DLP) on a minimum of twenty average-sized pediatric patients in each category were recorded to calculate a mean site CTDI v and DLP value. The rounded 75 th percentile was used to calculate a pediatric DRL for each hospital, and then region by compiling all results. Data were collected for 3600 pediatric patients. Pediatric CT DRL for two age groups: <1 year (CTDI v and DLP of head [20 mGy, 352 mGy.cm], chest [7 mGy, 120 mGy.cm] and abdomen [12 mGy, 252 mGy.cm]), and 1-5 years (CTDI v and DLP of head [38 mGy, 505 mGy.cm], chest [8 mGy, 132 mGy.cm] and abdomen [14 mGy, 270 mGy.cm]) for select procedures have been calculated. Proposed pediatric DRLs of CTDI v and DLP for head procedure were lower, and for chest and abdomen procedures were higher than European pediatric DRLs for both age groups.

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... is properly positioned. With modern CT scanners, your child will hear only slight buzzing, clicking and whirring sounds as the ... be taken to protect the welfare of your child, including close ... they should have a CT study only if it is essential for making a diagnosis ...

Computed tomography of pediatric abdominal masses

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Kook, Shin Ho; Ko, Eun Joo; Chung, Eun Chul; Suh, Jung Soo; Rhee, Chung Sik [College of Medicine, Ewha Womans University, Seoul (Korea, Republic of)

1988-02-15

Ultrasonography is a very useful diagnostic modality for evaluation of the pediatric abdominal masses, due to faster, cheaper, and no radiation hazard than CT. But CT has more advantages in assessing precise anatomic location, and extent of the pathologic process, and also has particular value in defining the size, relation of the mass to surrounding organs and detection of lymphadenopathy. We analyzed CT features of 35 cases of pathologically proven pediatric abdominal masses for recent 2 years at Ewha Woman's University Hospital. The results were as follows: 1.The most common originating site was kidney (20 cases, 57.1%); followed by gastrointestinal (5 cases, 14.3%), nonrenal retroperitoneal (4 cases, 11.4%), hepatobiliary (3 cases, 8.6%), and genital (3 cases, 8.6%) in order of frequency. 2.The most common mass was hydronephrosis (11 cases, 31.4%), Wilms' tumor (7 cases, 20.0%), neuroblastoma, choledochal cyst, periappendiceal abscess (3 cases, 8.6%, respectively), ovarian cyst (2 cases, 5.7%) were next in order of frequency. 3.Male to female ratio was 4:5 and choledochal cyst and ovarian cyst were found only in females. The most prevalent age group was 1-3 year old (12 cases, 34.3%). 4.With CT, the diagnosis of hydronephrosis was easy in all cases and could evaluate of its severity, renal function and obstruction site with high accuracy. 5.Wilms' tumor and neuroblastoma were relatively well differentiated by their characteristic CT features; such as location, shape, margin, middle cross, calyceal appearance and calcification, etc. 6.Ovarian and mensentric cysts had similar CT appearance. 7.In other pediatric abdominal masses, CT provided excellent information about anatomic detail, precise extent of tumor and differential diagnostic findings. So, CT is useful imaging modality for the demonstration and diagnosis of abdominal mass lesions in pediatric patients.

Reappraisal of Pediatric Diastatic Skull Fractures in the 3-Dimensional CT Era: Clinical Characteristics and Comparison of Diagnostic Accuracy of Simple Skull X-Ray, 2-Dimensional CT, and 3-Dimensional CT.

Science.gov (United States)

Sim, Sook Young; Kim, Hyun Gi; Yoon, Soo Han; Choi, Jong Wook; Cho, Sung Min; Choi, Mi Sun

2017-12-01

Diastatic skull fractures (DSFs) in children are difficult to detect in skull radiographs before they develop into growing skull fractures; therefore, little information is available on this topic. However, recent advances in 3-dimensional (3D) computed tomography (CT) imaging technology have enabled more accurate diagnoses of almost all forms of skull fracture. The present study was undertaken to document the clinical characteristics of DSFs in children and to determine whether 3D CT enhances diagnostic accuracy. Two hundred and ninety-two children younger than 12 years with skull fractures underwent simple skull radiography, 2-dimensional (2D) CT, and 3DCT. Results were compared with respect to fracture type, location, associated lesions, and accuracy of diagnosis. DSFs were diagnosed in 44 (15.7%) of children with skull fractures. Twenty-two patients had DSFs only, and the other 22 had DSFs combined with compound or mixed skull fractures. The most common fracture locations were the occipitomastoid (25%) and lambdoid (15.9%). Accompanying lesions consisted of subgaleal hemorrhages (42/44), epidural hemorrhages (32/44), pneumocephalus (17/44), and subdural hemorrhages (3/44). A total of 17 surgical procedures were performed on 15 of the 44 patients. Fourteen and 19 patients were confirmed to have DSFs by skull radiography and 2D CT, respectively, but 3D CT detected DSFs in 43 of the 44 children (P skull radiography or 2D CT for detecting DSFs. This finding indicates that 3D CT should be used routinely rather than 2D CT for the assessment of pediatric head trauma. Copyright © 2017 Elsevier Inc. All rights reserved.

Update on radiation safety and dose reduction in pediatric neuroradiology

International Nuclear Information System (INIS)

Mahesh, Mahadevappa

2015-01-01

The number of medical X-ray imaging procedures is growing exponentially across the globe. Even though the overall benefit from medical X-ray imaging procedures far outweighs any associated risks, it is crucial to take all necessary steps to minimize radiation risks to children without jeopardizing image quality. Among the X-ray imaging studies, except for interventional fluoroscopy procedures, CT studies constitute higher dose and therefore draw considerable scrutiny. A number of technological advances have provided ways for better and safer CT imaging. This article provides an update on the radiation safety of patients and staff and discusses dose optimization in medical X-ray imaging within pediatric neuroradiology. (orig.)

Update on radiation safety and dose reduction in pediatric neuroradiology

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Mahesh, Mahadevappa [Johns Hopkins University School of Medicine, The Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States)

2015-09-15

The number of medical X-ray imaging procedures is growing exponentially across the globe. Even though the overall benefit from medical X-ray imaging procedures far outweighs any associated risks, it is crucial to take all necessary steps to minimize radiation risks to children without jeopardizing image quality. Among the X-ray imaging studies, except for interventional fluoroscopy procedures, CT studies constitute higher dose and therefore draw considerable scrutiny. A number of technological advances have provided ways for better and safer CT imaging. This article provides an update on the radiation safety of patients and staff and discusses dose optimization in medical X-ray imaging within pediatric neuroradiology. (orig.)

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... may cause cancer. However, CT scans result in a low-level exposure. Whether such levels cause cancer is debatable but because it is possible, every effort is made to limit the amount of radiation children may receive from a CT scan. One of the best ways of ...

18F-FDG PET/CT in follow-up evaluation in pediatric patients with Langerhans histiocytosis.

Science.gov (United States)

Garcia, J R; Riera, E; Bassa, P; Mourelo, S; Soler, M

We evaluated the impact of 18 F-FDG PET/CT in identifying sites of active disease and to assess therapeutic follow up in a group of pediatric patients with Langerhans cell histiocytosis (LCH). During 2007-2013, 13 18 F-FDG PET/CT studies were performed for follow-up in 7 patients with a diagnosis of LCH (4 female, 3 male; 1-12 years-old). PET findings were analyzed and correlated with the CT and MRI. Findings were also follow-up by these techniques. PET was negative in 4 patients (all diagnosed with bone lesions and one with pituitary involvement also). CT findings showed residual morphological bone lesions in all patients, and hypophysis MRI study showed no abnormal signal. PET remained negative at 10, 14, 25 and 28 months, and no new lesions on CT and MRI were detected. PET was positive in 3 patients (one with cervical lymphadenopathy and 2 with bone lesions, one also with pituitary involvement not identified by PET). CT findings showed pathological cervical lymphadenopathy (n=1), bone lesions (n=2) and also a pituitary MRI lesion (n=1). In a patient with cervical lymphadenopathy histology demonstrated LCH involvement. In the other 2 patients, PET remained positive with an increase of 18 F-FDG bone uptake at 17 and 19 months. In our preliminar study, 18 F-FDG PET is a useful imaging procedure, along with other diagnostic tools, for identification of active lesions. Copyright © 2017 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

Post transplant lymphoproliferative disease in pediatric solid organ transplant patients: A possible role for [{sup 18}F]-FDG-PET(/CT) in initial staging and therapy monitoring

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Falck, C. von [Department of Diagnostic Radiology, Medizinische Hochschule Hannover (Medical School Hanover), Carl-Neuberg-Strasse 1, 30625 Hannover (Germany)], E-mail: Falck.Christian.von@mh-hannover.de; Maecker, B. [Department of Pediatric Hematology and Oncology, Medizinische Hochschule Hannover (Medical School Hanover), Carl-Neuberg-Strasse 1, 30625 Hannover (Germany); Schirg, E. [Department of Diagnostic Radiology, Medizinische Hochschule Hannover (Medical School Hanover), Carl-Neuberg-Strasse 1, 30625 Hannover (Germany); Boerner, A.R.; Knapp, W.H. [Department of Nuclear Medicine, Medizinische Hochschule Hannover (Medical School Hanover), Carl-Neuberg-Strasse 1, 30625 Hannover (Germany); Klein, C. [Department of Pediatric Hematology and Oncology, Medizinische Hochschule Hannover (Medical School Hanover), Carl-Neuberg-Strasse 1, 30625 Hannover (Germany); Galanski, M. [Department of Diagnostic Radiology, Medizinische Hochschule Hannover (Medical School Hanover), Carl-Neuberg-Strasse 1, 30625 Hannover (Germany)

2007-09-15

Post transplant lymphoproliferative disease (PTLD) is a severe complication after solid organ or bone marrow transplantation. In pediatric transplant recipients PTLD is the most common malignancy. The aim of this study was to evaluate a possible role for positron emission tomography with [{sup 18}F]-2-fluoro-2-desoxy-glucose (FDG) in the initial staging and in therapy monitoring of pediatric patients suffering from biopsy-proven CD20-positive PTLD after solid organ transplantation. Seven pediatric patients were included. All available imaging studies - CT (n = 15), MRI (n = 16) and PET/PETCT (n = 16) - were reviewed on a lesion by lesion base. The performance of FDG-PET in the initial staging and during therapy with a chimeric anti-CD20 antibody was compared to conventional cross sectional imaging and correlated with the clinical outcome. FDG-PET identified all sites of disease as shown by CT/MRI and helped to clarify the significance of equivocal findings. The initial stage of disease was correctly identified by FDG-PET alone when compared to CT/MRI. During therapy, FDG-PET was superior to conventional cross-sectional imaging in the early evaluation of response.

Abdominal and Pelvic CT

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Full Text Available ... CT scanning. top of page Additional Information and Resources RTAnswers.org: Radiation Therapy for Bladder Cancer Radiation ... Image Gallery Patient undergoing computed tomography (CT) scan View full size with caption Pediatric Content Some imaging ...

Tissue quantification for development of pediatric phantom

International Nuclear Information System (INIS)

Alves, A.F.F.; Miranda, J.R.A.; Pina, D.R.

2013-01-01

The optimization of the risk- benefit ratio is a major concern in the pediatric radiology, due to the greater vulnerability of children to the late somatic effects and genetic effects of exposure to radiation compared to adults. In Brazil, it is estimated that the causes of death from head trauma are 18 % for the age group between 1-5 years and the radiograph is the primary diagnostic test for the detection of skull fracture . Knowing that the image quality is essential to ensure the identification of structures anatomical and minimizing errors diagnostic interpretation, this paper proposed the development and construction of homogeneous phantoms skull, for the age group 1-5 years. The construction of the phantoms homogeneous was performed using the classification and quantification of tissue present in the skull of pediatric patients. In this procedure computational algorithms were used, using Matlab, to quantify distinct biological tissues present in the anatomical regions studied , using pictures retrospective CT scans. Preliminary data obtained from measurements show that between the ages of 1-5 years, assuming an average anteroposterior diameter of the pediatric skull region of the 145.73 ± 2.97 mm, can be represented by 92.34 mm ± 5.22 of lucite and 1.75 ± 0:21 mm of aluminum plates of a provision of PEP (Pacient equivalent phantom). After its construction, the phantoms will be used for image and dose optimization in pediatric protocols process to examinations of computerized radiography

Computed Tomography (CT) -- Sinuses

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Full Text Available ... Share your patient story here Images × Image Gallery Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related ...

Abdominal and Pelvic CT

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Full Text Available ... Share your patient story here Images × Image Gallery Patient undergoing computed tomography (CT) scan View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related ...

Computed Tomography (CT) -- Head

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Full Text Available ... Share your patient story here Images × Image Gallery Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related ...

Optimizing CT radiation dose based on patient size and image quality: the size-specific dose estimate method

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Larson, David B. [Stanford University School of Medicine, Department of Radiology, Stanford, CA (United States)

2014-10-15

The principle of ALARA (dose as low as reasonably achievable) calls for dose optimization rather than dose reduction, per se. Optimization of CT radiation dose is accomplished by producing images of acceptable diagnostic image quality using the lowest dose method available. Because it is image quality that constrains the dose, CT dose optimization is primarily a problem of image quality rather than radiation dose. Therefore, the primary focus in CT radiation dose optimization should be on image quality. However, no reliable direct measure of image quality has been developed for routine clinical practice. Until such measures become available, size-specific dose estimates (SSDE) can be used as a reasonable image-quality estimate. The SSDE method of radiation dose optimization for CT abdomen and pelvis consists of plotting SSDE for a sample of examinations as a function of patient size, establishing an SSDE threshold curve based on radiologists' assessment of image quality, and modifying protocols to consistently produce doses that are slightly above the threshold SSDE curve. Challenges in operationalizing CT radiation dose optimization include data gathering and monitoring, managing the complexities of the numerous protocols, scanners and operators, and understanding the relationship of the automated tube current modulation (ATCM) parameters to image quality. Because CT manufacturers currently maintain their ATCM algorithms as secret for proprietary reasons, prospective modeling of SSDE for patient populations is not possible without reverse engineering the ATCM algorithm and, hence, optimization by this method requires a trial-and-error approach. (orig.)

FDG PET/CT in pediatric primary bone tumours: comparison with conventional imaging (CI) and management impact assesment

International Nuclear Information System (INIS)

Stege, Claudia; London, Kevin; Cross, Siobhan; Howman-Giles, Robert; Onikul, Ella; Graf, Nicole; Pozza, L.D.

2009-01-01

Full text: To evaluate PET/CT in pediatric primary bone tumours (PBT), the accuracy, clinical impact, prognostic indicators in predicting tumour response to therapy and determining epiphyseal involvement were compared to Cl. Methods: A retrospective review of PET/CT scans with CI was performed. Lesions were compared to a reference standard: histopathology or follow up >6 mths. Pt based analysis was performed for clinical impact. Prognostic indicators (SUYmax, tumour size) were compared to histopathology response post chemotherapy. Results: 43 pts (average 12.9 yrs) with osteosarcoma (I 8), Ewing's sarcoma (21), PNE (4) were analysed. 109 PET/CT scans with CI scans were evaluated (371 lesions). 33 lesions were discordant. Accuracy of PET/CT was higher for all lesions than CI (95% vs92%) but sensitivity was lower (79% vs 83%). Excluding lung lesions, sensitivities increased for PET/CT and CI (92% vs 89%). 9pts had PET/CT staging and follow up with histopathological evaluation post chemotherapy: 2pts poor responders, 7 good responders. Good responders had a higher SUYmax at diagnosis compared to poor responders (av 13.84 vs 7.95) but reduced more [10.5(70%) vs 3.5( 45%)]following chemotherapy. There were no false negatives for epiphyseal involvement for PET/CT and CI but one PET/CT was false positive. Conclusion: PET/CT is less sensitive in small lung lesions, but more sensitive in other areas compared to Cl. SUYmax at diagnosis is a poor predictor of response, but percent decrease post therapy was associated with therapeutic response. Change in tumour size on MR is a poor predictor of response. There is improved clinical impact with PET/CT in patient management.

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... type your comment or suggestion into the following text box: Comment: E-mail: Area code: Phone no: Thank ... View full size with caption Pediatric Content Some imaging tests ...

Imaging of primary pediatric lymphoma of bone

International Nuclear Information System (INIS)

Milks, Kathryn S.; McLean, Thomas W.; Anthony, Evelyn Y.

2016-01-01

Primary pediatric bone lymphoma is a rare form of non-Hodgkin lymphoma. Unlike nodal forms of lymphoma, imaging abnormalities in lymphoma of bone do not resolve rapidly in conjunction with treatment and radiologic findings can remain abnormal for years, making it difficult to evaluate treatment response. To evaluate the utility of imaging in assessment of patients with primary pediatric bone lymphoma. At our institution between 2004 and 2013, six cases of pathology-proven primary pediatric bone lymphoma were diagnosed. Retrospective chart review was performed to assess imaging utilization. Our data were qualitatively compared with existing literature to construct an algorithm for imaging patients with primary lymphoma of bone. Imaging evaluation of patients with primary pediatric bone lymphoma was highly variable at our institution. Conventional imaging was routinely used to evaluate response to treatment, despite lack of appreciable osseous change. Imaging in the absence of symptoms did not alter clinical management. Only positron emission tomography CT (PET/CT) proved capable of demonstrating imaging changes from the pretreatment to the post-treatment scans that were consistent with the clinical response to treatment. Surveillance imaging is likely unnecessary in patients with a known diagnosis of pediatric lymphoma of bone. Pretreatment and post-treatment PET/CT is likely sufficient to assess response. There is little data to support the use of interim and surveillance PET/CT. (orig.)

Dose coefficients in pediatric and adult abdominopelvic CT based on 100 patient models

Science.gov (United States)

Tian, Xiaoyu; Li, Xiang; Segars, W. Paul; Frush, Donald P.; Paulson, Erik K.; Samei, Ehsan

2013-12-01

Recent studies have shown the feasibility of estimating patient dose from a CT exam using CTDIvol-normalized-organ dose (denoted as h), DLP-normalized-effective dose (denoted as k), and DLP-normalized-risk index (denoted as q). However, previous studies were limited to a small number of phantom models. The purpose of this work was to provide dose coefficients (h, k, and q) across a large number of computational models covering a broad range of patient anatomy, age, size percentile, and gender. The study consisted of 100 patient computer models (age range, 0 to 78 y.o.; weight range, 2-180 kg) including 42 pediatric models (age range, 0 to 16 y.o.; weight range, 2-80 kg) and 58 adult models (age range, 18 to 78 y.o.; weight range, 57-180 kg). Multi-detector array CT scanners from two commercial manufacturers (LightSpeed VCT, GE Healthcare; SOMATOM Definition Flash, Siemens Healthcare) were included. A previously-validated Monte Carlo program was used to simulate organ dose for each patient model and each scanner, from which h, k, and q were derived. The relationships between h, k, and q and patient characteristics (size, age, and gender) were ascertained. The differences in conversion coefficients across the scanners were further characterized. CTDIvol-normalized-organ dose (h) showed an exponential decrease with increasing patient size. For organs within the image coverage, the average differences of h across scanners were less than 15%. That value increased to 29% for organs on the periphery or outside the image coverage, and to 8% for distributed organs, respectively. The DLP-normalized-effective dose (k) decreased exponentially with increasing patient size. For a given gender, the DLP-normalized-risk index (q) showed an exponential decrease with both increasing patient size and patient age. The average differences in k and q across scanners were 8% and 10%, respectively. This study demonstrated that the knowledge of patient information and CTDIvol/DLP values may

Dose coefficients in pediatric and adult abdominopelvic CT based on 100 patient models

International Nuclear Information System (INIS)

Tian, Xiaoyu; Samei, Ehsan; Li, Xiang; Segars, W Paul; Frush, Donald P; Paulson, Erik K

2013-01-01

Recent studies have shown the feasibility of estimating patient dose from a CT exam using CTDI vol -normalized-organ dose (denoted as h), DLP-normalized-effective dose (denoted as k), and DLP-normalized-risk index (denoted as q). However, previous studies were limited to a small number of phantom models. The purpose of this work was to provide dose coefficients (h, k, and q) across a large number of computational models covering a broad range of patient anatomy, age, size percentile, and gender. The study consisted of 100 patient computer models (age range, 0 to 78 y.o.; weight range, 2–180 kg) including 42 pediatric models (age range, 0 to 16 y.o.; weight range, 2–80 kg) and 58 adult models (age range, 18 to 78 y.o.; weight range, 57–180 kg). Multi-detector array CT scanners from two commercial manufacturers (LightSpeed VCT, GE Healthcare; SOMATOM Definition Flash, Siemens Healthcare) were included. A previously-validated Monte Carlo program was used to simulate organ dose for each patient model and each scanner, from which h, k, and q were derived. The relationships between h, k, and q and patient characteristics (size, age, and gender) were ascertained. The differences in conversion coefficients across the scanners were further characterized. CTDI vol -normalized-organ dose (h) showed an exponential decrease with increasing patient size. For organs within the image coverage, the average differences of h across scanners were less than 15%. That value increased to 29% for organs on the periphery or outside the image coverage, and to 8% for distributed organs, respectively. The DLP-normalized-effective dose (k) decreased exponentially with increasing patient size. For a given gender, the DLP-normalized-risk index (q) showed an exponential decrease with both increasing patient size and patient age. The average differences in k and q across scanners were 8% and 10%, respectively. This study demonstrated that the knowledge of patient information and CTDI vol

The role of CT angiography in the evaluation of pediatric renovascular hypertension

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Kurian, Jessica [The Perelman School of Medicine, University of Pennsylvania, Department of Radiology, The Children' s Hospital of Philadelphia, Philadelphia, PA (United States); The Children' s Hospital at Montefiore, Bronx, NY (United States); Epelman, Monica [The Perelman School of Medicine, University of Pennsylvania, Department of Radiology, The Children' s Hospital of Philadelphia, Philadelphia, PA (United States); Nemours Children' s Hospital, Department of Radiology, Orlando, FL (United States); Darge, Kassa; Nijs, Els [The Perelman School of Medicine, University of Pennsylvania, Department of Radiology, The Children' s Hospital of Philadelphia, Philadelphia, PA (United States); Meyers, Kevin [The Perelman School of Medicine, University of Pennsylvania, Division of Nephrology, The Children' s Hospital of Philadelphia, Philadelphia, PA (United States); Hellinger, Jeffrey C. [The Perelman School of Medicine, University of Pennsylvania, Department of Radiology, The Children' s Hospital of Philadelphia, Philadelphia, PA (United States); New York Cardiovascular Institute and Lenox Hill Radiology, New York, NY (United States)

2013-04-15

Historically, the evaluation of renovascular hypertension has been accomplished by US, renal scintigraphy and digital subtraction angiography. Based on its high accuracy reported in adults renal CT angiography (CTA) with pediatric-appropriate low radiation dose techniques has become an important tool in the workup of renovascular hypertension in children. Renal CTA has several advantages over more conventional imaging modalities, including rapid and non-invasive acquisition, high resolution and easy reproducibility. Additionally, in our experience high-quality renal CTA can be performed using low-dose radiation exposures and can be acquired without sedation in most instances. This article illustrates by examples the usefulness of renal CTA for diagnosis of childhood renovascular hypertension and provides an overview of renal CTA findings in the most common childhood renovascular diseases. (orig.)

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info About Us News Physician Resources Professions Site Index A-Z Children's (Pediatric) ...

Imaging Pediatric Spondylolysis: A Systematic Review.

Science.gov (United States)

Tofte, Josef N; CarlLee, Tyler L; Holte, Andrew J; Sitton, Sean E; Weinstein, Stuart L

2017-05-15

A systematic review. The aim of this study was to provide an evidence-based recommendation for when and how to employ imaging studies when diagnosing back pain thought to be caused by spondylolysis in pediatric patients. Spondylolysis is a common structural cause of back pain in pediatric patients. The radiologic methods and algorithms used to diagnose spondylolysis are inconsistent among practitioners. A literature review was performed in PubMed and Cochrane databases using the search terms "spondylolysis," "pediatric," "adolescent," "juvenile," "young," "lumbar," "MRI," "bone scan," "CT," and "SPECT." After inclusion criteria were applied, 13 articles pertaining to diagnostic imaging of pediatric spondylolysis were analyzed. Ten papers included sensitivity calculations for comparing imaging performance. The average sensitivity of magnetic resonance imaging (MRI) with computed tomography (CT) as the standard of reference was 81.4%. When compared with single-photon emission CT (SPECT), the average sensitivity of CT was 85% and the sensitivity of MRI was 80%. Thirteen studies made a recommendation as to how best to perform diagnostic imaging of patients with clinically suspected spondylolysis. When compared with two-view plain films, bone scans had seven to nine times the effective radiation dose, while four-view plain films and CT were approximately double. Of the diagnostic methods examined, MRI was the most expensive followed by CT, bone scan, four-view plain films, and two-view plain films. Due to their efficacy, low cost, and low radiation exposure, we find two-view plain films to be the best initial study. With unusual presentations or refractory courses, practitioners should pursue advanced imaging. MRI should be used in early diagnosis and CT in more persistent courses. However, the lack of rigorous studies makes it difficult to formulate concrete recommendations. 3.

A Pilot Study Assessing ECG versus ECHO Ventriculoventricular Optimization in Pediatric Resynchronization Patients.

Science.gov (United States)

Punn, Rajesh; Hanisch, Debra; Motonaga, Kara S; Rosenthal, David N; Ceresnak, Scott R; Dubin, Anne M

2016-02-01

Cardiac resynchronization therapy indications and management are well described in adults. Echocardiography (ECHO) has been used to optimize mechanical synchrony in these patients; however, there are issues with reproducibility and time intensity. Pediatric patients add challenges, with diverse substrates and limited capacity for cooperation. Electrocardiographic (ECG) methods to assess electrical synchrony are expeditious but have not been extensively studied in children. We sought to compare ECHO and ECG CRT optimization in children. Prospective, pediatric, single-center cross-over trial comparing ECHO and ECG optimization with CRT. Patients were assigned to undergo either ECHO or ECG optimization, followed for 6 months, and crossed-over to the other assignment for another 6 months. ECHO pulsed-wave tissue Doppler and 12-lead ECG were obtained for 5 VV delays. ECG optimization was defined as the shortest QRSD and ECHO optimization as the lowest dyssynchrony index. ECHOs/ECGs were interpreted by readers blinded to optimization technique. After each 6 month period, these data were collected: ejection fraction, velocimetry-derived cardiac index, quality of life, ECHO-derived stroke distance, M-mode dyssynchrony, study cost, and time. Outcomes for each optimization method were compared. From June 2012 to December 2013, 19 patients enrolled. Mean age was 9.1 ± 4.3 years; 14 (74%) had structural heart disease. The mean time for optimization was shorter using ECG than ECHO (9 ± 1 min vs. 68 ± 13 min, P cost for charges was $4,400 ± 700 less for ECG. No other outcome differed between groups. ECHO optimization of synchrony was not superior to ECG optimization in this pilot study. ECG optimization required less time and cost than ECHO optimization. © 2015 Wiley Periodicals, Inc.

Subjective and objective image differences in pediatric computed tomography cardiac angiography using lower iodine concentration

International Nuclear Information System (INIS)

Hwang, Jae-Yeon; Choo, Ki Seok; Choi, Yoon Young; Kim, Jin Hyeok; Ryu, Hwaseong; Kim, Yong-Woo; Jeon, Ung Bae; Nam, Kyung Jin; Han, Junhee

2017-01-01

Several recent studies showed the optimal contrast enhancement with a low-concentration and iso-osmolar contrast media in both adult and pediatric patients. However, low contrast media concentrations are not routinely used due to concerns of suboptimal enhancement of cardiac structures and small vessels. To evaluate the feasibility of using iso-osmolar contrast media containing a low iodine dose for CT cardiac angiography at 80 kilovolts (kVp) in neonates and infants. The iodixanol 270 group consisted of 79 CT scans and the iopromide 370 group of 62 CT scans in patients ≤1 year old. Objective measurement of the contrast enhancement was analyzed and contrast-to-noise ratios of the ascending aorta and left ventricle were calculated. Regarding subjective measurement, a four-point scale system was devised to evaluate degrees of contrast enhancement, image noise, motion artifact and overall image quality of each image set. Reader performance for correctly differentiating iodixanol 270 and iopromide 370 by visual assessment was evaluated. Group objective and subjective measurements were nonsignificantly different. Overall sensitivity, specificity and diagnostic accuracy for correctly differentiating iodixanol 270 and iopromide 370 by visual assessment were 42.8%, 59%, and 50%, respectively. The application of iodixanol 270 achieved optimal enhancement for performing pediatric cardiac CT angiography at 80 kVp in neonates and infants. Objective measurements of contrast enhancement and subjective image quality assessments were not statistically different in the iodixanol 270 and iopromide 370 groups. (orig.)

Subjective and objective image differences in pediatric computed tomography cardiac angiography using lower iodine concentration

Energy Technology Data Exchange (ETDEWEB)

Hwang, Jae-Yeon [Pusan National University Yangsan Hospital, Department of Radiology, Yangsan-si, Gyeongsangnam-do (Korea, Republic of); Pusan National University Yangsan Hospital, Research Institute for Convergence of Biomedical Science and Technology, Yangsan-si, Gyeongsangnam-do (Korea, Republic of); Choo, Ki Seok; Choi, Yoon Young; Kim, Jin Hyeok; Ryu, Hwaseong; Kim, Yong-Woo; Jeon, Ung Bae; Nam, Kyung Jin [Pusan National University Yangsan Hospital, Department of Radiology, Yangsan-si, Gyeongsangnam-do (Korea, Republic of); Han, Junhee [Pusan National University Yangsan Hospital, Division of Biostatistics, Research Institute for Convergence of Biomedical Science and Technology, Yangsan-si, Gyeongsangnam-do (Korea, Republic of)

2017-05-15

Several recent studies showed the optimal contrast enhancement with a low-concentration and iso-osmolar contrast media in both adult and pediatric patients. However, low contrast media concentrations are not routinely used due to concerns of suboptimal enhancement of cardiac structures and small vessels. To evaluate the feasibility of using iso-osmolar contrast media containing a low iodine dose for CT cardiac angiography at 80 kilovolts (kVp) in neonates and infants. The iodixanol 270 group consisted of 79 CT scans and the iopromide 370 group of 62 CT scans in patients ≤1 year old. Objective measurement of the contrast enhancement was analyzed and contrast-to-noise ratios of the ascending aorta and left ventricle were calculated. Regarding subjective measurement, a four-point scale system was devised to evaluate degrees of contrast enhancement, image noise, motion artifact and overall image quality of each image set. Reader performance for correctly differentiating iodixanol 270 and iopromide 370 by visual assessment was evaluated. Group objective and subjective measurements were nonsignificantly different. Overall sensitivity, specificity and diagnostic accuracy for correctly differentiating iodixanol 270 and iopromide 370 by visual assessment were 42.8%, 59%, and 50%, respectively. The application of iodixanol 270 achieved optimal enhancement for performing pediatric cardiac CT angiography at 80 kVp in neonates and infants. Objective measurements of contrast enhancement and subjective image quality assessments were not statistically different in the iodixanol 270 and iopromide 370 groups. (orig.)

Abdominal and Pelvic CT

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Full Text Available ... and Resources RTAnswers.org: Radiation Therapy for Bladder Cancer Radiation Therapy for Colorectal Cancer top of page This page was reviewed on ... with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. ... Images related to Computed Tomography (CT) - Abdomen and ...

SU-E-I-23: A General KV Constrained Optimization of CNR for CT Abdominal Imaging

International Nuclear Information System (INIS)

Weir, V; Zhang, J

2015-01-01

Purpose: While Tube current modulation has been well accepted for CT dose reduction, kV adjusting in clinical settings is still at its early stage. This is mainly due to the limited kV options of most current CT scanners. kV adjusting can potentially reduce radiation dose and optimize image quality. This study is to optimize CT abdomen imaging acquisition based on the assumption of a continuous kV, with the goal to provide the best contrast to noise ratio (CNR). Methods: For a given dose (CTDIvol) level, the CNRs at different kV and pitches were measured with an ACR GAMMEX phantom. The phantom was scanned in a Siemens Sensation 64 scanner and a GE VCT 64 scanner. A constrained mathematical optimization was used to find the kV which led to the highest CNR for the anatomy and pitch setting. Parametric equations were obtained from polynomial fitting of plots of kVs vs CNRs. A suitable constraint region for optimization was chosen. Subsequent optimization yielded a peak CNR at a particular kV for different collimations and pitch setting. Results: The constrained mathematical optimization approach yields kV of 114.83 and 113.46, with CNRs of 1.27 and 1.11 at the pitch of 1.2 and 1.4, respectively, for the Siemens Sensation 64 scanner with the collimation of 32 x 0.625mm. An optimized kV of 134.25 and 1.51 CNR is obtained for a GE VCT 64 slice scanner with a collimation of 32 x 0.625mm and a pitch of 0.969. At 0.516 pitch and 32 x 0.625 mm an optimized kV of 133.75 and a CNR of 1.14 was found for the GE VCT 64 slice scanner. Conclusion: CNR in CT image acquisition can be further optimized with a continuous kV option instead of current discrete or fixed kV settings. A continuous kV option is a key for individualized CT protocols

SU-E-I-23: A General KV Constrained Optimization of CNR for CT Abdominal Imaging

Energy Technology Data Exchange (ETDEWEB)

Weir, V; Zhang, J [University of Kentucky, Lexington, KY (United States)

2015-06-15

Purpose: While Tube current modulation has been well accepted for CT dose reduction, kV adjusting in clinical settings is still at its early stage. This is mainly due to the limited kV options of most current CT scanners. kV adjusting can potentially reduce radiation dose and optimize image quality. This study is to optimize CT abdomen imaging acquisition based on the assumption of a continuous kV, with the goal to provide the best contrast to noise ratio (CNR). Methods: For a given dose (CTDIvol) level, the CNRs at different kV and pitches were measured with an ACR GAMMEX phantom. The phantom was scanned in a Siemens Sensation 64 scanner and a GE VCT 64 scanner. A constrained mathematical optimization was used to find the kV which led to the highest CNR for the anatomy and pitch setting. Parametric equations were obtained from polynomial fitting of plots of kVs vs CNRs. A suitable constraint region for optimization was chosen. Subsequent optimization yielded a peak CNR at a particular kV for different collimations and pitch setting. Results: The constrained mathematical optimization approach yields kV of 114.83 and 113.46, with CNRs of 1.27 and 1.11 at the pitch of 1.2 and 1.4, respectively, for the Siemens Sensation 64 scanner with the collimation of 32 x 0.625mm. An optimized kV of 134.25 and 1.51 CNR is obtained for a GE VCT 64 slice scanner with a collimation of 32 x 0.625mm and a pitch of 0.969. At 0.516 pitch and 32 x 0.625 mm an optimized kV of 133.75 and a CNR of 1.14 was found for the GE VCT 64 slice scanner. Conclusion: CNR in CT image acquisition can be further optimized with a continuous kV option instead of current discrete or fixed kV settings. A continuous kV option is a key for individualized CT protocols.

Usefulness of {sup 99m}Tc-ECD brain SPECT in acute onset pediatric CNS diseases. In comparison with CT and MRI

Energy Technology Data Exchange (ETDEWEB)

Hashimoto, Teisuke; Chikatsu, Hiroko; Nishiyama, Hiromune; Endo, Hiroko; Kono, Tatsuo; Iimura, Fumitoshi; Kuwashima, Shigeko; Saiki, Natoru; Fujioka, Mutsuhisa [Dokkyo Univ., Mibu, Tochigi (Japan). School of Medicine

2001-07-01

The purpose of this study was to assess the usefulness of regional cerebral blood flow (rCBF) measured by {sup 99m}Tc-L, L-ethyl cysteinate dimer (ECD) brain SPECT in the acute onset type of pediatric central nervous system (CNS) diseases. Thirteen children (7 girls, 6 boys, 4 month-12 years of age) who were diagnosed with 9 cases of viral encephalitis, two cases of febrile convulsion and one each of migraine and metabolic disorder underwent {sup 99m}Tc-ECD brain SPECT, CT and/or MRI within one week interval. The incidence of abnormal findings in the 13 patients was 96.4% (30/31) on {sup 99m}Tc-ECD brain SPECT, 17.6% (3/17) on CT and 63.6% (14/22) on MRI. The positive detection rate of {sup 99m}Tc-ECD brain SPECT was statistically (P<0.01 by a {chi}{sup 2} and/or Fisher's exact probability test) higher than those of CT and MRI. And the changes in rCBF were demonstrated. {sup 99m}Tc-ECD brain SPECT is a useful examination for the diagnosis and follow up management in patients with the acute onset type of pediatric CNS diseases. (author)

Children's (Pediatric) Magnetic Resonance Imaging

Medline Plus

Full Text Available ... work? Unlike conventional x-ray examinations and computed tomography (CT) scans, MRI does not utilize ionizing radiation. Instead, ... Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic Resonance Imaging (MRI) Safety Contrast Materials Children ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... wear during the procedure. Metal objects including jewelry, eyeglasses, hearing aids, non-permanent retainers and hairpins may ... and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media ...

Children's (Pediatric) CT (Computed Tomography)

Medline Plus

Full Text Available ... your child. top of page Additional Information and Resources The Alliance for Radiation Safety in Pediatric Imaging's " ... To locate a medical imaging or radiation oncology provider in your community, you can search the ACR- ...

How to study optimal timing of PET/CT for monitoring of cancer treatment

DEFF Research Database (Denmark)

Vach, Werner; Høilund-Carlsen, Poul Flemming; Fischer, Barbara Malene Bjerregaard

2011-01-01

Purpose: The use of PET/CT for monitoring treatment response in cancer patients after chemo- or radiotherapy is a very promising approach to optimize cancer treatment. However, the timing of the PET/CT-based evaluation of reduction in viable tumor tissue is a crucial question. We investigated how...

Characterization of adaptive statistical iterative reconstruction algorithm for dose reduction in CT: A pediatric oncology perspective

International Nuclear Information System (INIS)

Brady, S. L.; Yee, B. S.; Kaufman, R. A.

2012-01-01

Purpose: This study demonstrates a means of implementing an adaptive statistical iterative reconstruction (ASiR™) technique for dose reduction in computed tomography (CT) while maintaining similar noise levels in the reconstructed image. The effects of image quality and noise texture were assessed at all implementation levels of ASiR™. Empirically derived dose reduction limits were established for ASiR™ for imaging of the trunk for a pediatric oncology population ranging from 1 yr old through adolescence/adulthood. Methods: Image quality was assessed using metrics established by the American College of Radiology (ACR) CT accreditation program. Each image quality metric was tested using the ACR CT phantom with 0%–100% ASiR™ blended with filtered back projection (FBP) reconstructed images. Additionally, the noise power spectrum (NPS) was calculated for three common reconstruction filters of the trunk. The empirically derived limitations on ASiR™ implementation for dose reduction were assessed using (1, 5, 10) yr old and adolescent/adult anthropomorphic phantoms. To assess dose reduction limits, the phantoms were scanned in increments of increased noise index (decrementing mA using automatic tube current modulation) balanced with ASiR™ reconstruction to maintain noise equivalence of the 0% ASiR™ image. Results: The ASiR™ algorithm did not produce any unfavorable effects on image quality as assessed by ACR criteria. Conversely, low-contrast resolution was found to improve due to the reduction of noise in the reconstructed images. NPS calculations demonstrated that images with lower frequency noise had lower noise variance and coarser graininess at progressively higher percentages of ASiR™ reconstruction; and in spite of the similar magnitudes of noise, the image reconstructed with 50% or more ASiR™ presented a more smoothed appearance than the pre-ASiR™ 100% FBP image. Finally, relative to non-ASiR™ images with 100% of standard dose across the

CT-guided interventions in children; Computertomografisch gesteuerte Interventionen bei Kindern

Energy Technology Data Exchange (ETDEWEB)

Honnef, D.; Wildberger, J.E.; Schubert, H.; Hohl, C.; Guenther, R.W.; Mahnken, A. [Technische Hochschule Aachen (Germany). Klinik fuer Radiologische Diagnostik

2007-06-15

In pediatric CT-guided interventions specific features have to be taken into account. Due to a lack of cooperation or limited ability to cooperate, procedures are often performed using analgosedation or general anesthesia. To provide radiation protection, justified indication for CT-guided intervention is necessary and sonography and MRI are to be preferred whenever possible. CT examinations also need to be dose-adapted with sequential scanning and a tube voltage and tube current reduction compared to pediatric diagnostic CT studies must be ensured. Gonad shields are recommended for male patients. Biopsy device selection depends on the assumed tumor entity since histology and also immunohistochemical, molecular pathological and cytogenetical analysis are necessary to differentiate pediatric tumors (small, round, blue cell tumors). In addition to diagnostic procedures, therapeutic interventions (drainage, injection therapies, neurolysis, and radiofrequency ablation) can also be used in children and can provide an alternative to surgery in selected cases. With justified indications and precise performance, CT-guided interventions can be successful in pediatric patients with limited risks. (orig.)

Supply chain optimization for pediatric perioperative departments.

Science.gov (United States)

Davis, Janice L; Doyle, Robert

2011-09-01

Economic challenges compel pediatric perioperative departments to reduce nonlabor supply costs while maintaining the quality of patient care. Optimization of the supply chain introduces a framework for decision making that drives fiscally responsible decisions. The cost-effective supply chain is driven by implementing a value analysis process for product selection, being mindful of product sourcing decisions to reduce supply expense, creating logistical efficiency that will eliminate redundant processes, and managing inventory to ensure product availability. The value analysis approach is an analytical methodology for product selection that involves product evaluation and recommendation based on consideration of clinical benefit, overall financial impact, and revenue implications. Copyright © 2011 AORN, Inc. Published by Elsevier Inc. All rights reserved.

Radiation protection for the eyes of the children experiencing an operation of artificial cochlear implant against CT scan

International Nuclear Information System (INIS)

Liu Changsheng; Zheng Xiaohua; Li Maojing; Wei Wenzhou; Pan Ewu; Tang Guangqiao; Zhang Duanlian

2006-01-01

Objective: To optimize the CT scanning parameters in pediatric temporal bone examination with artificial cochlear implant and reduce its radiation hazards. Methods: The temporal bones of 87 patients with suspected inner ear disease which include 31 experienced artificial cochlear implant were scanned by HRCT. Regarding adult scan parameters as a criteria, properly adjusted the scanning dose and scanning angle until the quality of CT images was beyond the diagnosis demands. Finally the exposed doses, single scanning CT dose index weighted (CTDI w ) and dose length product (DLP) were analysed. Results: Compared with adult temporal bone scanning, the exposure value and CTDI w were reduced to 66.67%-83.33%, DLP of temporal bone scanning in pediatrics was reduced to 66.67%-83.33%, moreover, the imaging quality of tridimensional reconstruction for inner ear and implant electrode was improved. Conclusion: The proper reduction of CT scan exposure on preoperative and postoperative children with cochlear implants and the proper adjustment of scan angle can significantly reduce the exposure dose to local temporal bone and effectually avoid the damage to lens of children. (authors)

The ALARA (as low as reasonably achievable) concept in pediatric interventional and fluoroscopic imaging: striving to keep radiation doses as low as possible during fluoroscopy of pediatric patients - a white paper executive summary

International Nuclear Information System (INIS)

Strauss, Keith J.; Kaste, Sue C.

2006-01-01

ALARA represents a practice mandate adhering to the principle of keeping radiation doses to patients and personnel As Low As Reasonably Achievable. This concept is strongly endorsed by the Society for Pediatric Radiology, particularly in the use of procedures and modalities involving higher radiation doses such as CT and fluoroscopic examinations of pediatric patients. There is no doubt that medical imaging, which has undergone tremendous technological advances in recent decades, is integral to patient care. However, these technological advances generally precede the knowledge of end-users concerning the optimal use and correct operation of the resulting imaging equipment, and such knowledge is essential to minimizing potential risks to the patients. Current imaging methods must be optimized for radiation dose reduction in pediatric patients who might be as much as ten times more radiosensitive than adults. Unlike straightforward radiographic examinations, radiation dose to the patient during fluoroscopy is dependent on the operator's training, experience with the fluoroscope, and efficiency in completing a diagnostic study. The range of pediatric radiation doses from fluoroscopy is wide because this examination is performed not only by pediatric radiologists but also by general radiologists who occasionally care for children, interventional cardiologists, gastroenterologists, urologists and others. Thus, a venue where multidisciplinary interaction by this variety of operators can occur serves to improve pediatric patient care

Three-dimensional CT of the pediatric spine

International Nuclear Information System (INIS)

Starshak, R.J.; Crawford, C.R.; Waisman, R.C.; Sty, J.R.

1987-01-01

CT of the spine has been shown to be useful in evaluating congenital, neoplastic, inflammatory, and traumatic lesions. Any portion of the neural arch may be involved by these disease processes. However, the complex nature of the spinal column can make evaluation of these abnormalities difficult on axial CT. This is especially true if the spine is distorted by scoliosis, kyphosis, or lordosis. The principal advantage of three-dimensional CT is its ability to display the surface relationships of complicated objects. The complexity of the spinal axis makes it ideal for study with three-dimensional CT. This presentation illustrates the advantages and drawbacks of three-dimensional CT in spinal abnormalities in children

MO-DE-204-02: Optimization of the Patient CT Dose in Europe

International Nuclear Information System (INIS)

Tsapaki, V.

2016-01-01

The main topic of the session is to show how dose optimization is being implemented in various regions of the world, including Europe, Australia, North America and other regions. A multi-national study conducted under International Atomic Energy Agency (IAEA) across more than 50 less resourced countries gave insight into patient radiation doses and safety practices in CT, mammography, radiography and interventional procedures, both for children and adults. An important outcome was the capability development on dose assessment and management. An overview of recent European projects related to CT radiation dose and optimization both to adults and children will be presented. Existing data on DRLs together with a European methodology proposed on establishing and using DRLs for paediatric radiodiagnostic imaging and interventional radiology practices will be shown. Compared with much of Europe at least, many Australian imaging practices are relatively new to the task of diagnostic imaging dose optimisation. In 2008 the Australian Government prescribed a requirement to periodically compare patient radiation doses with diagnostic reference levels (DRLs), where DRLs have been established. Until recently, Australia had only established DRLs for computed tomography (CT). Regardless, both professional society and individual efforts to improved data collection and develop optimisation strategies across a range of modalities continues. Progress in this field, principally with respect to CT and interventional fluoroscopy will be presented. In the US, dose reduction and optimization efforts for computed tomography have been promoted and mandated by several organizations and accrediting entities. This presentation will cover the general motivation, implementation, and implications of such efforts. Learning Objectives: Understand importance of the dose optimization in Diagnostic Radiology. See how this goal is achieved in different regions of the World. Learn about the global trend

MO-DE-204-02: Optimization of the Patient CT Dose in Europe

Energy Technology Data Exchange (ETDEWEB)

Tsapaki, V. [Konstantopoulio General Hospital (Greece)

2016-06-15

The main topic of the session is to show how dose optimization is being implemented in various regions of the world, including Europe, Australia, North America and other regions. A multi-national study conducted under International Atomic Energy Agency (IAEA) across more than 50 less resourced countries gave insight into patient radiation doses and safety practices in CT, mammography, radiography and interventional procedures, both for children and adults. An important outcome was the capability development on dose assessment and management. An overview of recent European projects related to CT radiation dose and optimization both to adults and children will be presented. Existing data on DRLs together with a European methodology proposed on establishing and using DRLs for paediatric radiodiagnostic imaging and interventional radiology practices will be shown. Compared with much of Europe at least, many Australian imaging practices are relatively new to the task of diagnostic imaging dose optimisation. In 2008 the Australian Government prescribed a requirement to periodically compare patient radiation doses with diagnostic reference levels (DRLs), where DRLs have been established. Until recently, Australia had only established DRLs for computed tomography (CT). Regardless, both professional society and individual efforts to improved data collection and develop optimisation strategies across a range of modalities continues. Progress in this field, principally with respect to CT and interventional fluoroscopy will be presented. In the US, dose reduction and optimization efforts for computed tomography have been promoted and mandated by several organizations and accrediting entities. This presentation will cover the general motivation, implementation, and implications of such efforts. Learning Objectives: Understand importance of the dose optimization in Diagnostic Radiology. See how this goal is achieved in different regions of the World. Learn about the global trend

Radiation doses in head CT examinations in Serbia: comparison among different CT units

International Nuclear Information System (INIS)

Arandjic, D.; Ciraj-Bjelac, O.; Bozovic, P.; Stankovic, J.; Hadnadjev, D.; Stojanovic, S.

2012-01-01

A rapid increase in number of Computed Tomography (CT) examinations has been observed world wide. As haed CT is the most frequent CT examination, the purpose of this study was to collect and analyse patient doses in children and adults in different CT units for this procedure. The study included 8 CT units from three manufacturers (Siemens, Toshiba and General Electric). Data for adults and pediatric patients were collected in terms of CTDIvol and DLP values. The doses were estimated as a mean value of 10 patients on each CT unit. For pediatrics, doses were collected for four age groups (0-1year, >1-5years, >5-10years and >10-15years). Comparing different manufacturers and the same number of detector rows it was observed that, in case of 16 slices units, doses were very similar on Siemens and General Electric scanner. CTDIvol and DLP on Siemens scanner were 60 mGy and 1066 mGy·cm, respectively, while on General Electric those values were 66 mGy and 1050 mGy·cm. However, this trend was not observed in case of 64 slices units. CTDIvol and DLP values collected on Toshiba were much higher (177 mGy and 2109 mGy·cm) than in case of Siemens scanner (59 mGy and 1060 mGy·cm). Doses on 16 and 64 slices Siemens scanners were very similar, while on 4 slices were higher. Except in two units, doses were were in line with DRLs. In case of pediatrics, doses increase with patient age and again Siemens scanner showed the lowest values while the highest were observed on Toshiba. (authors)

Model-based Iterative Reconstruction: Effect on Patient Radiation Dose and Image Quality in Pediatric Body CT

Science.gov (United States)

Dillman, Jonathan R.; Goodsitt, Mitchell M.; Christodoulou, Emmanuel G.; Keshavarzi, Nahid; Strouse, Peter J.

2014-01-01

Purpose To retrospectively compare image quality and radiation dose between a reduced-dose computed tomographic (CT) protocol that uses model-based iterative reconstruction (MBIR) and a standard-dose CT protocol that uses 30% adaptive statistical iterative reconstruction (ASIR) with filtered back projection. Materials and Methods Institutional review board approval was obtained. Clinical CT images of the chest, abdomen, and pelvis obtained with a reduced-dose protocol were identified. Images were reconstructed with two algorithms: MBIR and 100% ASIR. All subjects had undergone standard-dose CT within the prior year, and the images were reconstructed with 30% ASIR. Reduced- and standard-dose images were evaluated objectively and subjectively. Reduced-dose images were evaluated for lesion detectability. Spatial resolution was assessed in a phantom. Radiation dose was estimated by using volumetric CT dose index (CTDIvol) and calculated size-specific dose estimates (SSDE). A combination of descriptive statistics, analysis of variance, and t tests was used for statistical analysis. Results In the 25 patients who underwent the reduced-dose protocol, mean decrease in CTDIvol was 46% (range, 19%–65%) and mean decrease in SSDE was 44% (range, 19%–64%). Reduced-dose MBIR images had less noise (P > .004). Spatial resolution was superior for reduced-dose MBIR images. Reduced-dose MBIR images were equivalent to standard-dose images for lungs and soft tissues (P > .05) but were inferior for bones (P = .004). Reduced-dose 100% ASIR images were inferior for soft tissues (P ASIR. Conclusion CT performed with a reduced-dose protocol and MBIR is feasible in the pediatric population, and it maintains diagnostic quality. © RSNA, 2013 Online supplemental material is available for this article. PMID:24091359

Optimized control of X-ray exposure and image noise using a particular multislice CT scanner

International Nuclear Information System (INIS)

Yamamoto, Shuji; Suzuki, Masahiro; Kakinuma, Ryutaro; Moriyama, Noriyuki; Koyama, Yoshihiro; Nagasawa, Hirofumi

2008-01-01

Patient dose reduction in computed tomography (CT) always results in a trade off between radiation exposure and image quality. There are few reports that estimate the relationship between image quality and X-ray exposure in CT examinations as one optimal index. The purpose of this study was to determine the optimal parameter settings enabling a low radiation exposure without compromising image quality using a particular 4-row multislice CT (MSCT) scanner (Aquilion VZ 4-slice CT scanner, Toshiba Medical Systems Corporation, Otawara, Tochigi, Japan). Normalized dose divided by image noise for helical pitches (nDNR: normalized dose to noise ratio) were calculated in consideration of beam collimation and tube current-time product. Optimal tube current-time product was calculated using the nDNR for the helical pitches based on user-defined standards of quality of the CT image. As a result, the nDNR proved to be well-supported to decrease the patient exposure in various exposure conditions of MSCT scans; however, the dose and image noise did not show a linear relation to the helical pitch. In conclusion, nDNR can be applied to patient dose reduction while keeping an acceptable image quality using a particular 4-row MSCT scanner. (author)

The diagnostic analysis using the CT scan, of cystic lesions in the cranial basis in pediatric cases

International Nuclear Information System (INIS)

Oshida, Kinya; Ishimori, Shoji; Okada, Ryoho.

1978-01-01

It is the purpose of this paper to evaluate the low-density lesions of those pediatric cases which were treated at this hospital in the six months beginning July, 1977, using a CT scan, EMI-1010 Type. Among 1500 consecutive cases diagnosed with the CT scan, 300 pediatric cases were included. We discuss particularly eight patients, two with arachnoidal cysts, two with cystic craniopharyngiomas, two with cystic cerebellar astrocytomas and two with Dandy-Walker syndromes, one of which was accompanied by corpus callosum agenesis. The distribution of ages was from 2 to 12 years. We calculated the matrix of each slice of these patients, CT scan in the cystic lesions, the area including the cystic lesion, ventricles and brain tissue, predominantly the white matter or interhemispheric cortex including white matter, without dye enhancement. The x-ray absorption values of the low-density lesions were definitely different according to the nature of the cystic contents. The mean values of x-ray absorption, the standard deviations, and the sample sizes of each area in the matrix were compared statistically with those of cystic lesions. The mean values of the arachnoidal cysts, the contents of which were almost like CSF, were 17 - 21; that of cystic craniopharyngiomas, the contents of which were a thick yellowic fluid with cholesterin crystals, were 23 - 28; those of cerebellar astrocytomas, with Froin positive fluid, were 22 - 24; the cystic lesions of the posterior fossa in the Dandy-Walker syndrome were 8 - 13. The difference in the x-ray absorption values (Hounsfield number) were compared statistically for analyzing the differential diagnosis of these low-density lesions by calculating the P-values. All of these lesions were verified by surgical explorations. (author)

CT reconstruction and MRI fusion of 3D rotational angiography in the evaluation of pediatric cerebrovascular lesions

Energy Technology Data Exchange (ETDEWEB)

Muthusami, Prakash; Rea, Vanessa; Shroff, Manohar [The Hospital for Sick Children, Pediatric Neuroradiology and Image Guided Therapy, Department of Diagnostic Imaging, Toronto, ON (Canada); Shkumat, Nicholas [The Hospital for Sick Children, Medical Physics, Department of Diagnostic Imaging, Toronto, ON (Canada); Chiu, Albert H. [Institute of Neurological Sciences, Prince of Wales Hospital, Department of Interventional Neuroradiology, Randwick, NSW (Australia)

2017-06-15

Complex neurovascular lesions in children require precise anatomic understanding for treatment planning. Although 3DRA is commonly employed for volumetric reformation in neurointerventional procedures, the ability to reconstruct this data into CT-like images (3DRA-CT) is not widely utilized. This study demonstrates the feasibility and usefulness of 3DRA-CT and subsequent MRI fusion for problem solving in pediatric neuroangiography. This retrospective study includes 18 3DRA-CT studies in 16 children (age 9.6 ± 3.8 years, range 2-16 years) over 1 year. After biplane 2D-digital subtraction angiography (DSA), 5-second 3DRA was performed with selective vessel injection either with or without subtraction. Images were reconstructed into CT sections which were post-processed to generate multiplanar reformation (MPR) and maximum intensity projection (MIP) images. Fusion was performed with 3D T1 MRI images to precisely demonstrate neurovascular relationships. Quantitative radiation metrics were extracted and compared against those for the entire examination and for corresponding biplane 2D-DSA acquisitions. In all 18 cases, the 3DRA procedure and MRI fusion were technically successful and provided clinically useful information relevant to management. The unsubtracted and subtracted 3DRA acquisitions were measured to deliver 5.9 and 132.2%, respectively, of the mean radiation dose of corresponding biplane 2D-DSA acquisitions and contributed 1.2 and 12.5%, respectively, to the total procedure dose. Lower radiation doses, high spatial resolution, and multiplanar reformatting capability make 3DRA-CT a useful adjunct to evaluate neurovascular lesions in children. Fusing 3DRA-CT data with MRI is an additional capability that can further enhance diagnostic information. (orig.)

Normal pediatric postmortem CT appearances

Energy Technology Data Exchange (ETDEWEB)

Klein, Willemijn M.; Bosboom, Dennis G.H.; Koopmanschap, Desiree H.J.L.M. [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Nievelstein, Rutger A.J. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Nikkels, Peter G.J. [University Medical Center Utrecht, Department of Pathology, Utrecht (Netherlands); Rijn, Rick R. van [Academic Medical Center, Department of Radiology, Amsterdam (Netherlands)

2015-04-01

Postmortem radiology is a rapidly developing specialty that is increasingly used as an adjunct to or substitute for conventional autopsy. The goal is to find patterns of disease and possibly the cause of death. Postmortem CT images bring to light processes of decomposition most radiologists are unfamiliar with. These postmortem changes, such as the formation of gas and edema, should not be mistaken for pathological processes that occur in living persons. In this review we discuss the normal postmortem thoraco-abdominal changes and how these appear on CT images, as well as how to differentiate these findings from those of pathological processes. (orig.)

Organ allocation in pediatric renal transplants: is there an optimal donor?

Science.gov (United States)

Pitt, Susan C; Vachharajani, Neeta; Doyle, Maria B; Lowell, Jeffrey A; Chapman, William C; Anderson, Christopher D; Shenoy, Surendra; Wellen, Jason R

2013-01-01

The 2005 revised allocation scheme for pediatric renal transplantation made the decision of whether to transplant an available living-donor (LD) kidney or use a deceased-donor (DD) kidney controversial. The aim of this study was to examine kidney allograft utilization, sensitization, and outcomes of pediatric transplant recipients. Between January 2000 and December 2009, 91 consecutive pediatric kidney recipients (transplanted. The LD (n = 38) and DD (n = 53) groups were similar in age, gender, dialysis status at transplant, warm ischemia time, and overall patient survival. LD recipients were more likely to be Caucasian (92 vs. 69%), receive older allografts (39 ± 10 vs. 23 ± 9 yr), and have fewer human leukocyte antigen (HLA) mismatches (3.3 ± 1.6 vs. 4.4 ± 1.5, p transplant was longer for LD recipients (97%, 91%, 87% vs. DD 89%, 79%, 58%, respectively, p transplant, 17 (33%) DD recipients had an available LD (mean age 40 yr). A greater proportion of all patients were moderately (PRA 21-79%) sensitized post-transplant (p organs was likely due to fewer HLA mismatched in this group. Nonetheless, LD organs appear to provide optimal outcomes in pediatric renal transplants when considering the risk of becoming sensitized post-transplant complicating later use of the LD kidney. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

MO-FG-CAMPUS-IeP1-03: Establishment of Provincial Diagnostic Reference Levels in Pediatric Imaging

International Nuclear Information System (INIS)

Tonkopi, E; O’Brien, K

2016-01-01

Purpose: To establish provincial diagnostic reference levels (DRLs) in pediatric general radiography and computed tomography (CT) as a tool for the optimization of exposure parameters. Methods: Patient dose survey was conducted in the only pediatric hospital in the province of Nova Scotia. The DRLs were established as the 75th percentile of patient dose distributions in different age groups. For routine radiography projections the DRLs were determined in terms of entrance surface dose (ESD) calculated from the radiation output measurements and the tube current-exposure time product (mAs) recorded for each examination. Patient thickness was measured by the technologist during the examination. The CR and DR systems, employing respectively a fixed technique and phototiming, were evaluated separately; a two-tailed Student’s t-test was used to determine the significance of differences between the means of dose distributions. The CT studies included routine head, chest, abdomen/pelvis, and chest/abdomen/pelvis. The volume CT dose index (CTDIvol) and dose-length product (DLP) values were extracted retrospectively from PACS. The correction factors based on the effective diameter of the patient were applied to the CT dosimetry metrics based on the standard phantoms. Results: The provincial DRLs were established in the following age groups: newborn, 1, 5, 10, and 15 year olds. In general radiography the DR systems demonstrated slightly lower dose than the CR for all views, however the differences were not statistically significant (p > 0.05) for all examinations. In CT the provincial DRLs were lower than the published data, except for head DLPs in all age categories. This might be due to the small patient sample size in the survey. Future work will include additional CT data collection over an extended period of time. Conclusion: Provincial DRLs were established in the dedicated children’s hospital to provide guidance for the other facilities in examinations of pediatric

MO-FG-CAMPUS-IeP1-03: Establishment of Provincial Diagnostic Reference Levels in Pediatric Imaging

Energy Technology Data Exchange (ETDEWEB)

Tonkopi, E [Dalhousie University (Canada); Queen Elizabeth II Health Sciences Ctr (Canada); O’Brien, K [Dalhousie University (Canada); IWK Health Centre, Halifax, NS (Canada)

2016-06-15

Purpose: To establish provincial diagnostic reference levels (DRLs) in pediatric general radiography and computed tomography (CT) as a tool for the optimization of exposure parameters. Methods: Patient dose survey was conducted in the only pediatric hospital in the province of Nova Scotia. The DRLs were established as the 75th percentile of patient dose distributions in different age groups. For routine radiography projections the DRLs were determined in terms of entrance surface dose (ESD) calculated from the radiation output measurements and the tube current-exposure time product (mAs) recorded for each examination. Patient thickness was measured by the technologist during the examination. The CR and DR systems, employing respectively a fixed technique and phototiming, were evaluated separately; a two-tailed Student’s t-test was used to determine the significance of differences between the means of dose distributions. The CT studies included routine head, chest, abdomen/pelvis, and chest/abdomen/pelvis. The volume CT dose index (CTDIvol) and dose-length product (DLP) values were extracted retrospectively from PACS. The correction factors based on the effective diameter of the patient were applied to the CT dosimetry metrics based on the standard phantoms. Results: The provincial DRLs were established in the following age groups: newborn, 1, 5, 10, and 15 year olds. In general radiography the DR systems demonstrated slightly lower dose than the CR for all views, however the differences were not statistically significant (p > 0.05) for all examinations. In CT the provincial DRLs were lower than the published data, except for head DLPs in all age categories. This might be due to the small patient sample size in the survey. Future work will include additional CT data collection over an extended period of time. Conclusion: Provincial DRLs were established in the dedicated children’s hospital to provide guidance for the other facilities in examinations of pediatric

A survey of post-discharge side effects of conscious sedation using chloral hydrate in pediatric CT and MR imaging

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Kao, S.C.; Adamson, S.D.; Tatman, L.H.; Berbaum, K.S. [Department of Radiology, Univ. of Iowa College of Medicine, Iowa City, IA (United States)

1999-04-01

Background. Limited information is available on post-discharge side effects of chloral hydrate sedation in pediatric imaging. Objective. To prospectively study the post-discharge side effects of chloral hydrate sedation in pediatric CT and MR imaging. Materials and methods. A total of 119 children undergoing CT and MRI were sedated using chloral hydrate with 89 % success (mean initial dose, 72 mg/kg body weight) and 98 % success after augmentation (mean total, 78 mg/kg body weight). The frequency of each post-discharge side effect was correlated with other side effects and 12 patient/technical parameters. Results. The survey was completed in 80 children. Sleepiness lasted for > 4 h in 28 %. Unsteadiness occurred in 68 % and hyperactivity in 29 %. Appetite became poor in 14 % and vomiting occurred in 15 %. Normal activity was resumed after > 4 h in 54 %. Sleep deprivation did not result in increased success or earlier onset of sedation and might be associated with hyperactivity. A higher dose did not result in an increased success rate or earlier onset of sedation within the dose range used in this study. Conclusion. Data on the post-discharge side effects of chloral hydrate sedation will be useful to radiologists, technologists, and nurses explaining to parents about sedation using this agent. (orig.) With 2 tabs., 24 refs.

A survey of post-discharge side effects of conscious sedation using chloral hydrate in pediatric CT and MR imaging

International Nuclear Information System (INIS)

Kao, S.C.; Adamson, S.D.; Tatman, L.H.; Berbaum, K.S.

1999-01-01

Background. Limited information is available on post-discharge side effects of chloral hydrate sedation in pediatric imaging. Objective. To prospectively study the post-discharge side effects of chloral hydrate sedation in pediatric CT and MR imaging. Materials and methods. A total of 119 children undergoing CT and MRI were sedated using chloral hydrate with 89 % success (mean initial dose, 72 mg/kg body weight) and 98 % success after augmentation (mean total, 78 mg/kg body weight). The frequency of each post-discharge side effect was correlated with other side effects and 12 patient/technical parameters. Results. The survey was completed in 80 children. Sleepiness lasted for > 4 h in 28 %. Unsteadiness occurred in 68 % and hyperactivity in 29 %. Appetite became poor in 14 % and vomiting occurred in 15 %. Normal activity was resumed after > 4 h in 54 %. Sleep deprivation did not result in increased success or earlier onset of sedation and might be associated with hyperactivity. A higher dose did not result in an increased success rate or earlier onset of sedation within the dose range used in this study. Conclusion. Data on the post-discharge side effects of chloral hydrate sedation will be useful to radiologists, technologists, and nurses explaining to parents about sedation using this agent. (orig.)

Intrathecally enhanced spinal CT in the early diagnosis of cerebrospinal fluid-borne metastasis in pediatric patients with primary brain tumors

International Nuclear Information System (INIS)

Wang, H.; Rosenbaum, A.E.; Ahn, H.S.; Zinreich, S.J.; Diffley, D.M.; Killmond, T.A.; Strauss, L.C.

1987-01-01

Early diagnosis and treatment of asymptomatic intraspinal cerebrospinal fluid-borne metastases can obviate serious sequelae in pediatric patients with known intracranial tumors. MR imaging is a superior imaging modality; however, in very young patients who need general anesthesia for immobilization and also for evaluation of small subarachnoid seedings, the authors found CT to be a valuable alternative. Twelve patients ranging in age from 3 months to 13 years underwent CT screening of the entire spine after intrathecal enhancement with 3-5 ml of metrizamide (100 mg iodine per milliliter) via a lumbar puncture. Intrathecal spinal metastases were found in 67% of the studied patients and even in a patient whose MR imaging examination failed to disclose the lesion

Optimizing Effectiveness in Electronic Prescriptions for Pediatric Outpatients: A Call for Responsive Action

Directory of Open Access Journals (Sweden)

Richard H. Parrish II

2014-09-01

Full Text Available A pediatric compounded non-sterile products repository (pCNP to optimize the effectiveness and safety of “off-label” use of compounded pharmacotherapy through complete transmission of electronic prescriptions across the continuum of care is described. The advent of electronic prescribing has the potential to refocus and resolve long-standing issues of prescription therapy for pediatric patients related to formulation, indication, dosing, and outcomes follow-up, among others. This white paper describes the architecture and function of the pCNP repository. Further, it calls on professional societies, health information technology (HIT and pharmaceutical industries, universities, and government to create a safer pediatric pharmacotherapy system across the continuum of care. This system would include pCNPs within the existing federal and corporate database structures for medical language, and integrates advanced system safety features as requirements for prescribing, compounding, and dispensing non-mass produced prescription therapies for children.

Benchmarking pediatric cranial CT protocols using a dose tracking software system: a multicenter study.

Science.gov (United States)

De Bondt, Timo; Mulkens, Tom; Zanca, Federica; Pyfferoen, Lotte; Casselman, Jan W; Parizel, Paul M

2017-02-01

To benchmark regional standard practice for paediatric cranial CT-procedures in terms of radiation dose and acquisition parameters. Paediatric cranial CT-data were retrospectively collected during a 1-year period, in 3 different hospitals of the same country. A dose tracking system was used to automatically gather information. Dose (CTDI and DLP), scan length, amount of retakes and demographic data were stratified by age and clinical indication; appropriate use of child-specific protocols was assessed. In total, 296 paediatric cranial CT-procedures were collected. Although the median dose of each hospital was below national and international diagnostic reference level (DRL) for all age categories, statistically significant (p-value benchmarking showed that further dose optimization and standardization is possible by using age-stratified protocols for paediatric cranial CT. Moreover, having a dose tracking system revealed that adult protocols are still applied for paediatric CT, a practice that must be avoided. • Significant differences were observed in the delivered dose between age-groups and hospitals. • Using age-adapted scanning protocols gives a nearly linear dose increase. • Sharing dose-data can be a trigger for hospitals to reduce dose levels.

TU-PIS-Exhibit Hall-01: CT Dose Optimization Technologies II

International Nuclear Information System (INIS)

Driesser, I; Angel, E

2014-01-01

Partners in Solutions is an exciting new program in which AAPM partners with our vendors to present practical “hands-on” information about the equipment and software systems that we use in our clinics. The imaging topic this year is CT scanner dose optimization capabilities. Note that the sessions are being held in a special purpose room built on the Exhibit Hall Floor, to encourage further interaction with the vendors. Siemens‘ Commitment to the Right Dose in Computed Tomography Presentation Time: 11:15 - 11:45 AM Providing sustainable clinical results at highest patient safety: This is the challenge in medical imaging. Especially for Computed Tomography this means applying not simply the lowest, but the right dose for sound diagnostic imaging. Consequently, Siemens is committed to deliver the right dose in CT. In order to reduce radiation to the right dose, the first step is to provide the right dose technology. Through decades of research and development in CT imaging, Siemens CT has constantly introduced new ideas leading to a comprehensive portfolio of unique CARE technologies to deliver the right dose. For example automated kV adjustment based on patient size and the clinical question with CARE kV and three generations of iterative reconstruction. Based on the right dose technology, the next step is to actually scan at the right dose. For this, it is key to know the right dose targets for every examination. Siemens continuously involves CT experts to push developments further and outline how users can best adapt their procedures to the right dose. For users to know whether they met the right dose targets, it is therefore important to understand and monitor the actual absolute dose values. All scanners are delivered with defined default protocols which automatically use the available right dose technologies. Finally, to deliver the right dose not just in singular cases, but ideally to patients everywhere, organizations need then to manage dose across

Pediatric AIDS. Neuroradiologic and neurodevelopmental findings

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Price, D.B.; Haller, J.O.; Kramer, J.; Hotson, G.C.; Loh, J.P.; Schlusselberg, D.; Inglese, C.M.; Jacobs, J.; Rose, A.L.; Menez-Bautista, R.

1988-09-01

A group of 23 pediatric patients seropositive for HIV antibody were studied by computed tomography and evaluated neurodevelopmentally. Significant neurodevelopmental delays were found in over 95% of the patients studied. CT findings in six patients were normal and thirteen of 23 (57%) had prominence of the CSF spaces. Less frequent findings included calcifications in the basal ganglia and white matter. Cerebral mass lesions included one case of lymphoma and one case of hemorrhage. The CT findings in the pediatric age group differs from the adult population in that that contrast enhancing inflammatory mass lesions are uncommon.

Diagnostic performance of 18F-FDG PET/CT and whole-body diffusion-weighted imaging with background body suppression (DWIBS) in detection of lymph node and bone metastases from pediatric neuroblastoma.

Science.gov (United States)

Ishiguchi, Hiroaki; Ito, Shinji; Kato, Katsuhiko; Sakurai, Yusuke; Kawai, Hisashi; Fujita, Naotoshi; Abe, Shinji; Narita, Atsushi; Nishio, Nobuhiro; Muramatsu, Hideki; Takahashi, Yoshiyuki; Naganawa, Shinji

2018-04-17

Recent many studies have shown that whole body "diffusion-weighted imaging with background body signal suppression" (DWIBS) seems a beneficial tool having higher tumor detection sensitivity without ionizing radiation exposure for pediatric tumors. In this study, we evaluated the diagnostic performance of whole body DWIBS and 18 F-FDG PET/CT for detecting lymph node and bone metastases in pediatric patients with neuroblastoma. Subjects in this retrospective study comprised 13 consecutive pediatric patients with neuroblastoma (7 males, 6 females; mean age, 2.9 ± 2.0 years old) who underwent both 18 F-FDG PET/CT and whole-body DWIBS. All patients were diagnosed as neuroblastoma on the basis of pathological findings. Eight regions of lymph nodes and 17 segments of skeletons in all patients were evaluated. The images of 123 I-MIBG scintigraphy/SPECT-CT, bone scintigraphy/SPECT, and CT were used to confirm the presence of lymph node and bone metastases. Two radiologists trained in nuclear medicine evaluated independently the uptake of lesions in 18 F-FDG PET/CT and the signal-intensity of lesions in whole-body DWIBS visually. Interobserver difference was overcome through discussion to reach a consensus. The sensitivities, specificities, and overall accuracies of 18 F-FDG PET/CT and whole-body DWIBS were compared using McNemer's test. Positive predictive values (PPVs) and negative predictive values (NPVs) of both modalities were compared using Fisher's exact test. The total numbers of lymph node regions and bone segments which were confirmed to have metastasis in the total 13 patients were 19 and 75, respectively. The sensitivity, specificity, overall accuracy, PPV, and NPV of 18 F-FDG PET/CT for detecting lymph node metastasis from pediatric neuroblastoma were 100, 98.7, 98.9, 95.0, and 100%, respectively, and those for detecting bone metastasis were 90.7, 73.1, 80.3, 70.1, and 91.9%, respectively. In contrast, the sensitivity, specificity, overall accuracy, PPV

Optimization of hybrid iterative reconstruction level and evaluation of image quality and radiation dose for pediatric cardiac computed tomography angiography

International Nuclear Information System (INIS)

Yang, Lin; Liang, Changhong; Zhuang, Jian; Huang, Meiping; Liu, Hui

2017-01-01

Hybrid iterative reconstruction can reduce image noise and produce better image quality compared with filtered back-projection (FBP), but few reports describe optimization of the iteration level. We optimized the iteration level of iDose"4 and evaluated image quality for pediatric cardiac CT angiography. Children (n = 160) with congenital heart disease were enrolled and divided into full-dose (n = 84) and half-dose (n = 76) groups. Four series were reconstructed using FBP, and iDose"4 levels 2, 4 and 6; we evaluated subjective quality of the series using a 5-grade scale and compared the series using a Kruskal-Wallis H test. For FBP and iDose"4-optimal images, we compared contrast-to-noise ratios (CNR) and size-specific dose estimates (SSDE) using a Student's t-test. We also compared diagnostic-accuracy of each group using a Kruskal-Wallis H test. Mean scores for iDose"4 level 4 were the best in both dose groups (all P < 0.05). CNR was improved in both groups with iDose"4 level 4 as compared with FBP. Mean decrease in SSDE was 53% in the half-dose group. Diagnostic accuracy for the four datasets were in the range 92.6-96.2% (no statistical difference). iDose"4 level 4 was optimal for both the full- and half-dose groups. Protocols with iDose"4 level 4 allowed 53% reduction in SSDE without significantly affecting image quality and diagnostic accuracy. (orig.)

Three-dimensional CT of the pediatric spine

International Nuclear Information System (INIS)

Starshak, R.J.; Crawford, C.R.; Waisman, R.C.; Sty, J.R.

1987-01-01

CT of the spine has been shown to be useful in evaluating congenital, neoplastic, inflammatory, and traumatic lesions. Any portion of the neural arch may be involved by these disease processes. The complex nature of the spinal column can make evaluation of these abnormalities difficult on axial CT. This is especially true if the spine is distorted by scoliosis, kyphosis, or lordosis. This exhibit illustrates the advantages and drawbacks of three-dimensional CT reconstructed images of spinal abnormalities in children

Optimization of the Contrast Mixture Ratio for Simultaneous Direct MR and CT Arthrography: an in Vitro Study

International Nuclear Information System (INIS)

Choi, Ja Young; Hong, Sung Hwan; Kim, Na Ra; Jun, Woo Sun; Moon, Sung Gyu; Kang, Heung Sik; Lee, Joon Woo; Choi, Jung Ah

2008-01-01

This study was designed to determine the optimal mixture ratio of gadolinium and iodinated contrast agent for simultaneous direct MR arthrography and CT arthrography. An in vitro study was performed utilizing mixtures of gadolinium at six different concentrations (0.625, 1.25, 2.5, 5.0, 10 and 20 mmol/L) and iodinated contrast agent at seven different concentrations (0, 12.5, 25, 37.5, 50, 75 and 92-99.9%). These mixtures were placed in tissue culture plates, and were then imaged with CT and MR (with T1-weighted sequences, proton-density sequences and T2-weighted sequences). CT numbers and signal intensities were measured. Pearson's correlation coefficients were used to assess the correlations between the gadolinium/iodinated contrast agent mixtures and the CT numbers/MR signal intensities. Scatter diagrams were plotted for all gadolinium/iodinated contrast agent combinations and two radiologists in consensus identified the mixtures that yielded the optimal CT numbers and MR signal intensities. The CT numbers showed significant correlation with iodinated contrast concentrations (r = 0.976, p < 0.001), whereas the signal intensities as measured on MR images showed a significant correlation with both gadolinium and iodinated contrast agent concentrations (r = -484 to -0.719, p < 0.001). A review of the CT and MR images, graphs, and scatter diagram of 42 combinations of the contrast agent showed that a concentration of 1.25 mmol/L gadolinium and 25% iodinated contrast agent was the best combination for simultaneous CT and MR imaging. A mixture of 1.25 mmol/L gadolinium and 25% iodinated contrast agent was found to be optimal for simultaneous direct MR arthrography and CT arthrography

Optimization of SPECT-CT Hybrid Imaging Using Iterative Image Reconstruction for Low-Dose CT: A Phantom Study.

Directory of Open Access Journals (Sweden)

Oliver S Grosser

Full Text Available Hybrid imaging combines nuclear medicine imaging such as single photon emission computed tomography (SPECT or positron emission tomography (PET with computed tomography (CT. Through this hybrid design, scanned patients accumulate radiation exposure from both applications. Imaging modalities have been the subject of long-term optimization efforts, focusing on diagnostic applications. It was the aim of this study to investigate the influence of an iterative CT image reconstruction algorithm (ASIR on the image quality of the low-dose CT images.Examinations were performed with a SPECT-CT scanner with standardized CT and SPECT-phantom geometries and CT protocols with systematically reduced X-ray tube currents. Analyses included image quality with respect to photon flux. Results were compared to the standard FBP reconstructed images. The general impact of the CT-based attenuation maps used during SPECT reconstruction was examined for two SPECT phantoms. Using ASIR for image reconstructions, image noise was reduced compared to FBP reconstructions for the same X-ray tube current. The Hounsfield unit (HU values reconstructed by ASIR were correlated to the FBP HU values(R2 ≥ 0.88 and the contrast-to-noise ratio (CNR was improved by ASIR. However, for a phantom with increased attenuation, the HU values shifted for low X-ray tube currents I ≤ 60 mA (p ≤ 0.04. In addition, the shift of the HU values was observed within the attenuation corrected SPECT images for very low X-ray tube currents (I ≤ 20 mA, p ≤ 0.001.In general, the decrease in X-ray tube current up to 30 mA in combination with ASIR led to a reduction of CT-related radiation exposure without a significant decrease in image quality.

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams Contrast Materials Anesthesia Safety Children and Radiation Safety Images ...

Normal uptake of F-18 FDG in the testis as assessed by PET/CT in a pediatric study population

International Nuclear Information System (INIS)

Goethals, I.; Vriendt, C.D.; Hoste, P.; Smeets, P.; Ham, H.

2009-01-01

The objective of this study was to investigate the correlation between the F-18 fluorodeoxyglucose (FDG) uptake in the normal testis as assessed by positron emission tomography (PET)-CT and patient age in a pediatric study population. The study population consisted of 22 subjects aged between 9 and 17 years. For these subjects 42 PET-CT scans were available for analysis. The testis was identified on the CT images. Mean standard uptake values and testicular volume were calculated based on manually drawn regions-of-interest over the organ. The correlation between mean standardized uptake value (SUV) and age as well as between testicular volume and age was calculated using Pearson's correlation coefficient. A strong and statistically significant positive correlation between F-18 FDG uptake in the testis and age was documented. The correlation coefficient was 0.406 in the analysis based on 42 PET-CT studies (p=0.005). The correlation between tracer uptake and age was reassessed based on 22 PET-CT studies including the last recorded PET-CT scan per patient. The correlation coefficient was 0.409 (p=0.05). In addition, based on 22 PET-CT scans, a strong and statistically significant positive correlation between testicular volume and age was documented (r=0.67, p<0.001). Whereas it was previously shown that in adult men there was a weak but statistically significant negative correlation between F-18 FDG uptake in the normal testis and age, we found a strong and statistically significant positive correlation in children and teenage boys. (author)

Cone-beam CT in paediatric dentistry. DIMITRA project position statement

International Nuclear Information System (INIS)

Oenning, Anne Caroline; Jacobs, Reinhilde; Pauwels, Ruben; Stratis, Andreas; Hedesiu, Mihaela; Salmon, Benjamin

2018-01-01

DIMITRA (dentomaxillofacial paediatric imaging: an investigation towards low-dose radiation induced risks) is a European multicenter and multidisciplinary project focused on optimizing cone-beam CT exposures for children and adolescents. With increasing use of cone-beam CT for dentomaxillofacial diagnostics, concern arises regarding radiation risks associated with this imaging modality, especially for children. Research evidence concerning cone-beam CT indications in children remains limited, while reports mention inconsistent recommendations for dose reduction. Furthermore, there is no paper using the combined and integrated information on the required indication-oriented image quality and the related patient dose levels. In this paper, therefore, the authors initiate an integrated approach based on current evidence regarding image quality and dose, together with the expertise of DIMITRA's members searching for a state of the art. The aim of this DIMITRA position statement is to provide indication-oriented and patient-specific recommendations regarding the main cone-beam CT applications in the pediatric field. The authors will review this position statement document when results regarding multidisciplinary approaches evolve, in a period of 5 years or earlier. (orig.)

Utility of plain radiographs and MRI in cervical spine clearance in symptomatic non-obtunded pediatric patients without high-impact trauma.

Science.gov (United States)

Moore, Justin M; Hall, Jonathan; Ditchfield, Michael; Xenos, Christopher; Danks, Andrew

2017-02-01

The optimal imaging modality for evaluating cervical spine trauma and optimizing management in the pediatric population is controversial. In pediatric populations, there are no well-established guidelines for cervical spine trauma evaluation and treatment. Currently, there is virtually no literature regarding imaging and management of symptomatic pediatric patients who present with cervical spine trauma without high-impact mechanism. This study aims to establish an optimal imaging strategy for this subgroup of trauma patients. We performed a retrospective review of pediatric patients (aged below 18 years) who were admitted to Monash Medical Centre, Melbourne, Australia between July 2011 and June 2015, who did not suffer a high-impact trauma but were symptomatic for cervical spine injury following cervical trauma. Imaging and management strategies were reviewed and results compared. Forty-seven pediatric patients were identified who met the inclusion criteria. Of these patients, 46 underwent cervical spine series (CSS) plain radiograph imaging. Thirty-four cases underwent magnetic resonance imaging (MRI) and 9 patients underwent CT. MRI was able to detect 4 cases of ligamentous injury, which were not seen in CSS imaging and was able to facilitate cervical spine clearance in a further two patients whose CSS radiographs were abnormal. In this study, MRI has a greater sensitivity and specificity when compared to CSS radiography in a symptomatic pediatric low-impact trauma population. Our data call in to question the routine use of CSS radiographs in children.

Non-contrast thin-section helical CT of urinary tract calculi in children

International Nuclear Information System (INIS)

Strouse, Peter J.; Bates, Gregory D.; Bloom, David A.; Goodsitt, Mitchell M.

2002-01-01

Background: Non-contrast thin-section helical CT has gained acceptance for the diagnosis of urinary tract calculi in adults, but experience with the technique in children is limited. Purpose: To evaluate the utility of non-contrast thin section helical CT for the diagnosis of urinary tract calculi in children. Materials and methods: Radiology databases at three pediatric institutions were searched to identify all pediatric patients evaluated by ''renal stone'' protocol CT scans (no oral or intravenous contrast, scans covering the entire urinary tract obtained in helical mode with narrow collimation (< 5 mm)). CT scans were reviewed for the primary finding of urinary tract calculi, for secondary signs of acute urinary tract obstruction and for evidence of alternative diagnoses. Medical records were reviewed to determine clinical presentation and to confirm the eventual diagnosis. Results: One hundred thirty-seven scans of 113 children (mean age: 11.2 years) were studied. Thirty-eight of 94 examinations (40%) performed on 82 children for acute pain and/or hematuria showed ureteral calculi. Alternative diagnoses were suggested by CT on 16 scans (17%). Twenty-eight scans were performed on 10 asymptomatic children with known calculus disease confirming renal stone burden on 21 scans (75%) and persistent ureteral calculi on 6 scans (21%). Upper tract calculi were demonstrated on 10 of 15 scans (67%) performed to evaluate for calculi in patients with known non-calculus genitourinary tract abnormalities. Conclusions: Non-contrast thin section helical CT is a useful method to diagnose urinary tract calculi in children. Radiation dose in this retrospective study may exceed the lowest possible radiation dose for diagnostic accuracy. Further research is needed to optimize CT imaging parameters, while maintaining diagnostic accuracy and minimizing radiation dose. (orig.)

Characterization of adaptive statistical iterative reconstruction algorithm for dose reduction in CT: A pediatric oncology perspective

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Brady, S. L.; Yee, B. S.; Kaufman, R. A. [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, Tennessee 38105 (United States)

2012-09-15

Purpose: This study demonstrates a means of implementing an adaptive statistical iterative reconstruction (ASiR Trade-Mark-Sign ) technique for dose reduction in computed tomography (CT) while maintaining similar noise levels in the reconstructed image. The effects of image quality and noise texture were assessed at all implementation levels of ASiR Trade-Mark-Sign . Empirically derived dose reduction limits were established for ASiR Trade-Mark-Sign for imaging of the trunk for a pediatric oncology population ranging from 1 yr old through adolescence/adulthood. Methods: Image quality was assessed using metrics established by the American College of Radiology (ACR) CT accreditation program. Each image quality metric was tested using the ACR CT phantom with 0%-100% ASiR Trade-Mark-Sign blended with filtered back projection (FBP) reconstructed images. Additionally, the noise power spectrum (NPS) was calculated for three common reconstruction filters of the trunk. The empirically derived limitations on ASiR Trade-Mark-Sign implementation for dose reduction were assessed using (1, 5, 10) yr old and adolescent/adult anthropomorphic phantoms. To assess dose reduction limits, the phantoms were scanned in increments of increased noise index (decrementing mA using automatic tube current modulation) balanced with ASiR Trade-Mark-Sign reconstruction to maintain noise equivalence of the 0% ASiR Trade-Mark-Sign image. Results: The ASiR Trade-Mark-Sign algorithm did not produce any unfavorable effects on image quality as assessed by ACR criteria. Conversely, low-contrast resolution was found to improve due to the reduction of noise in the reconstructed images. NPS calculations demonstrated that images with lower frequency noise had lower noise variance and coarser graininess at progressively higher percentages of ASiR Trade-Mark-Sign reconstruction; and in spite of the similar magnitudes of noise, the image reconstructed with 50% or more ASiR Trade-Mark-Sign presented a more

CT Dose Optimization in Pediatric Radiology: A Multiyear Effort to Preserve the Benefits of Imaging While Reducing the Risks.

Science.gov (United States)

Greenwood, Taylor J; Lopez-Costa, Rodrigo I; Rhoades, Patrick D; Ramírez-Giraldo, Juan C; Starr, Matthew; Street, Mandie; Duncan, James; McKinstry, Robert C

2015-01-01

The marked increase in radiation exposure from medical imaging, especially in children, has caused considerable alarm and spurred efforts to preserve the benefits but reduce the risks of imaging. Applying the principles of the Image Gently campaign, data-driven process and quality improvement techniques such as process mapping and flowcharting, cause-and-effect diagrams, Pareto analysis, statistical process control (control charts), failure mode and effects analysis, "lean" or Six Sigma methodology, and closed feedback loops led to a multiyear program that has reduced overall computed tomographic (CT) examination volume by more than fourfold and concurrently decreased radiation exposure per CT study without compromising diagnostic utility. This systematic approach involving education, streamlining access to magnetic resonance imaging and ultrasonography, auditing with comparison with benchmarks, applying modern CT technology, and revising CT protocols has led to a more than twofold reduction in CT radiation exposure between 2005 and 2012 for patients at the authors' institution while maintaining diagnostic utility. (©)RSNA, 2015.

PRACTICAL RECOMMENDATIONS OF DATA PREPROCESSING AND GEOSPATIAL MEASURES FOR OPTIMIZING THE NEUROLOGICAL AND OTHER PEDIATRIC EMERGENCIES MANAGEMENT

Directory of Open Access Journals (Sweden)

Ionela MANIU

2017-08-01

Full Text Available Time management, optimal and timed determination of emergency severity as well as optimizing the use of available human and material resources are crucial areas of emergency services. A starting point for achieving these optimizations can be considered the analysis and preprocess of real data from the emergency services. The benefits of performing this method consist in exposing more useful structures to data modelling algorithms which consequently will reduce overfitting and improves accuracy. This paper aims to offer practical recommendations for data preprocessing measures including feature selection and discretization of numeric attributes regarding age, duration of the case, season, period, week period (workday, weekend and geospatial location of neurological and other pediatric emergencies. An analytical, retrospective study was conducted on a sample consisting of 933 pediatric cases, from UPU-SMURD Sibiu, 01.01.2014 – 27.02.2017 period.

Confidence in Assessment of Lumbar Spondylolysis Using Three-Dimensional Volumetric T2-Weighted MRI Compared With Limited Field of View, Decreased-Dose CT.

Science.gov (United States)

Delavan, Joshua Adam; Stence, Nicholas V; Mirsky, David M; Gralla, Jane; Fadell, Michael F

2016-07-01

Limited z-axis-coverage computed tomography (CT) to evaluate for pediatric lumbar spondylolysis, altering the technique such that the dose to the patient is comparable or lower than radiographs, is currently used at our institution. The objective of the study was to determine whether volumetric 3-dimensional fast spin echo magnetic resonance imaging (3D MRI) can provide equal or greater diagnostic accuracy compared with limited CT in the diagnosis of pediatric lumbar spondylolysis without ionizing radiation. Volumetric 3D MRI can provide equal or greater diagnostic accuracy compared with low-dose CT for pediatric lumbar spondylolysis without ionizing radiation. Clinical review. Level 2. Three pediatric neuroradiologists evaluated 2-dimensional (2D) MRI, 2D + 3D MRI, and limited CT examinations in 42 pediatric patients who obtained imaging for low back pain and suspected spondylolysis. As there is no gold standard for the diagnosis of spondylolysis besides surgery, interobserver agreement and degree of confidence were compared to determine which modality is preferable. Decreased-dose CT provided a greater level of agreement than 2D MRI and 2D + 3D MRI. The kappa for rater agreement with 2D MRI, 2D + 3D MRI, and CT was 0.19, 0.32, and 1.0, respectively. All raters agreed in 31%, 40%, and 100% of cases with 2D MRI, 2D + 3D MRI, and CT. Lack of confidence was significantly lower with CT (0%) than with 2D MRI (30%) and 2D + 3D MRI (25%). For diagnosing spondylolysis, radiologist agreement and confidence trended toward improvement with the addition of a volumetric 3D MRI sequence to standard 2D MRI sequences compared with 2D MRI alone; however, agreement and confidence remain significantly greater using decreased-dose CT when compared with either MRI acquisition. Decreased-dose CT of the lumbar spine remains the optimal examination to confirm a high suspicion of spondylolysis, with dose essentially equivalent to radiographs. If clinical symptoms are not classic for

Primary hepatic artery embolization in pediatric blunt hepatic trauma.

Science.gov (United States)

Ong, Caroline C P; Toh, Luke; Lo, Richard H G; Yap, Te-Lu; Narasimhan, Kannan

2012-12-01

Non-operative management of isolated blunt hepatic trauma is recommended except when hemodynamic instability requires immediate laparotomy. Hepatic artery angioembolization is increasingly used for hepatic injuries with ongoing bleeding as demonstrated by contrast extravasation on the CT scan. It is used primarily or after laparotomy to control ongoing hemorrhage. Hepatic angioembolization as part of multimodality management of hepatic trauma is reported mainly in adults, with few pediatric case reports. We describe our institution experience with primary pediatric hepatic angioembolization and review the literature with regard to indications and complications. Two cases (3 and 8 years old), with high-grade blunt hepatic injuries with contrast extravasation on the CT scan were successfully managed by emergency primary hepatic angioembolization with minimal morbidity and avoided laparotomy. To date, the only reports of pediatric hepatic angioembolization for trauma are 5 cases for acute bleeding and 15 delayed cases for pseudoaneurysm. The role of hepatic angioembolization in the presence of an arterial blush on CT in adults is accepted, but contested in a pediatric series, despite higher transfusion rate and mortality rate. We propose that hepatic angioembolization should be considered adjunct treatment, in lieu of, or in addition to emergency laparotomy for hemostasis in pediatric blunt hepatic injury. Copyright © 2012 Elsevier Inc. All rights reserved.

Full dose reduction potential of statistical iterative reconstruction for head CT protocols in a predominantly pediatric population

Science.gov (United States)

Mirro, Amy E.; Brady, Samuel L.; Kaufman, Robert. A.

2016-01-01

Purpose To implement the maximum level of statistical iterative reconstruction that can be used to establish dose-reduced head CT protocols in a primarily pediatric population. Methods Select head examinations (brain, orbits, sinus, maxilla and temporal bones) were investigated. Dose-reduced head protocols using an adaptive statistical iterative reconstruction (ASiR) were compared for image quality with the original filtered back projection (FBP) reconstructed protocols in phantom using the following metrics: image noise frequency (change in perceived appearance of noise texture), image noise magnitude, contrast-to-noise ratio (CNR), and spatial resolution. Dose reduction estimates were based on computed tomography dose index (CTDIvol) values. Patient CTDIvol and image noise magnitude were assessed in 737 pre and post dose reduced examinations. Results Image noise texture was acceptable up to 60% ASiR for Soft reconstruction kernel (at both 100 and 120 kVp), and up to 40% ASiR for Standard reconstruction kernel. Implementation of 40% and 60% ASiR led to an average reduction in CTDIvol of 43% for brain, 41% for orbits, 30% maxilla, 43% for sinus, and 42% for temporal bone protocols for patients between 1 month and 26 years, while maintaining an average noise magnitude difference of 0.1% (range: −3% to 5%), improving CNR of low contrast soft tissue targets, and improving spatial resolution of high contrast bony anatomy, as compared to FBP. Conclusion The methodology in this study demonstrates a methodology for maximizing patient dose reduction and maintaining image quality using statistical iterative reconstruction for a primarily pediatric population undergoing head CT examination. PMID:27056425

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... order to produce clear images. Also, shorter scan times will make it easier for children to hold their breath during critical parts of the exam. CT scanning is painless, noninvasive ...

Benchmarking pediatric cranial CT protocols using a dose tracking software system: a multicenter study

Energy Technology Data Exchange (ETDEWEB)

Bondt, Timo de; Parizel, Paul M. [Antwerp University Hospital and University of Antwerp, Department of Radiology, Antwerp (Belgium); Mulkens, Tom [H. Hart Hospital, Department of Radiology, Lier (Belgium); Zanca, Federica [GE Healthcare, DoseWatch, Buc (France); KU Leuven, Imaging and Pathology Department, Leuven (Belgium); Pyfferoen, Lotte; Casselman, Jan W. [AZ St. Jan Brugge-Oostende AV Hospital, Department of Radiology, Brugge (Belgium)

2017-02-15

To benchmark regional standard practice for paediatric cranial CT-procedures in terms of radiation dose and acquisition parameters. Paediatric cranial CT-data were retrospectively collected during a 1-year period, in 3 different hospitals of the same country. A dose tracking system was used to automatically gather information. Dose (CTDI and DLP), scan length, amount of retakes and demographic data were stratified by age and clinical indication; appropriate use of child-specific protocols was assessed. In total, 296 paediatric cranial CT-procedures were collected. Although the median dose of each hospital was below national and international diagnostic reference level (DRL) for all age categories, statistically significant (p-value < 0.001) dose differences among hospitals were observed. The hospital with lowest dose levels showed smallest dose variability and used age-stratified protocols for standardizing paediatric head exams. Erroneous selection of adult protocols for children still occurred, mostly in the oldest age-group. Even though all hospitals complied with national and international DRLs, dose tracking and benchmarking showed that further dose optimization and standardization is possible by using age-stratified protocols for paediatric cranial CT. Moreover, having a dose tracking system revealed that adult protocols are still applied for paediatric CT, a practice that must be avoided. (orig.)

Children's (Pediatric) CT (Computed Tomography)

Science.gov (United States)

... a CT scan can be reformatted in multiple planes, and can even generate three-dimensional images. These ... child may have, and if there is a history of heart disease, asthma, diabetes, kidney disease or ...

Transthoracic Doppler echocardiography to predict optimal tube pulsing window for coronary artery CT angiography

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Sun, Gang, E-mail: cjr.sungang@vip.163.com [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Li, Min, E-mail: limin22000@yahoo.com.cn [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Jiang, Xiang-sen, E-mail: jiangxiangsen123@126.com [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Li, Li, E-mail: leely1976@yahoo.com.cn [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Peng, Zhao-hui, E-mail: zhaohuipeng_R@163.com [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Mu, Nan-nan, E-mail: munannan22000@sohu.com [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China)

2012-09-15

Rationale and objective: To evaluate the feasibility of transthoracic Doppler echocardiography to determine the optimal pulsing windows for CT coronary angiography to narrow the pulsing windows further, especially in higher heart rate. Materials and methods: Doppler was performed on 135 patients before CT scanning. For Doppler, the intervals with minimal motion were evaluated during both systole and diastole integrating electrocardiogram (ECG) intervals. For CT scanning, the retrospective ECG-gating was applied and the optimal reconstruction intervals were determined. The accuracy of Doppler analysis to predict the optimal reconstruction intervals was tested. The predicted length of pulsing windows was compared between Doppler analysis and traditional prospective ECG-gating protocol (heart rate ≦ 65 bpm, 60–76%; 66–79 bpm, 30–77%; ≧80 bpm, 31–47%). Results: According to Doppler analysis, the mean length of intervals with minimal motion in systole was 106.4 ± 39.2 ms and 125.2 ± 92.0 ms in diastole. When the intervals with minimal motion during diastole > 90 ms, the optimal reconstruction intervals were located at diastole; otherwise, at systole (P < 0.001). The optimal reconstruction intervals in 93.8% (132/135) patients could be predicted accurately by Doppler analysis. If the optimal reconstruction intervals predicted by Doppler were applied as the exposure windows, the mean length of pulsing windows should has been 105.2 ± 69.4 ms (range: 26.9–510.3 ms), which was significantly shorter than that of traditional prospective ECG-gating protocol (232.0 ± 120.2 ms, range: 93.2–427.3 ms, P < 0.001). Conclusion: Doppler can help detecting the optimal pulsing windows accurately. Prospective ECG-gating incorporating Doppler analysis may narrow pulsing windows significantly while maintaining image quality.

Transthoracic Doppler echocardiography to predict optimal tube pulsing window for coronary artery CT angiography

International Nuclear Information System (INIS)

Sun, Gang; Li, Min; Jiang, Xiang-sen; Li, Li; Peng, Zhao-hui; Mu, Nan-nan

2012-01-01

Rationale and objective: To evaluate the feasibility of transthoracic Doppler echocardiography to determine the optimal pulsing windows for CT coronary angiography to narrow the pulsing windows further, especially in higher heart rate. Materials and methods: Doppler was performed on 135 patients before CT scanning. For Doppler, the intervals with minimal motion were evaluated during both systole and diastole integrating electrocardiogram (ECG) intervals. For CT scanning, the retrospective ECG-gating was applied and the optimal reconstruction intervals were determined. The accuracy of Doppler analysis to predict the optimal reconstruction intervals was tested. The predicted length of pulsing windows was compared between Doppler analysis and traditional prospective ECG-gating protocol (heart rate ≦ 65 bpm, 60–76%; 66–79 bpm, 30–77%; ≧80 bpm, 31–47%). Results: According to Doppler analysis, the mean length of intervals with minimal motion in systole was 106.4 ± 39.2 ms and 125.2 ± 92.0 ms in diastole. When the intervals with minimal motion during diastole > 90 ms, the optimal reconstruction intervals were located at diastole; otherwise, at systole (P < 0.001). The optimal reconstruction intervals in 93.8% (132/135) patients could be predicted accurately by Doppler analysis. If the optimal reconstruction intervals predicted by Doppler were applied as the exposure windows, the mean length of pulsing windows should has been 105.2 ± 69.4 ms (range: 26.9–510.3 ms), which was significantly shorter than that of traditional prospective ECG-gating protocol (232.0 ± 120.2 ms, range: 93.2–427.3 ms, P < 0.001). Conclusion: Doppler can help detecting the optimal pulsing windows accurately. Prospective ECG-gating incorporating Doppler analysis may narrow pulsing windows significantly while maintaining image quality

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... images can be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide greater detail ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... is known that high levels of radiation may cause cancer. However, CT scans result in a low-level exposure. Whether such levels cause cancer is debatable but because it is possible, every ...

Pediatric chest imaging. Chest imaging in infants and children. 2. rev. ed.

Energy Technology Data Exchange (ETDEWEB)

Lucaya, Javier [Vall d' Hebron Hospitals, Barcelona (Spain). Dept. of Pediatric Radiology and Inst. of Diagnostic Imaging; Hospital Quiron, Barcelona (Spain). Dept. of Radiology; Strife, Janet L. (eds.) [Cincinnati Univ. Coll. of Medicine, Cincinnati, OH (United States). Dept. of Radiology Cincinnati Children' s Hospital Medical Center

2008-07-01

Imaging of the pediatric chest continues to evolve rapidly. All chapters in this 2nd edition of Pediatric Chest Imaging have been extensively updated, with additional disease-specific information and numerous new illustrations. The book thus presents the state of the art in the diagnosis of pediatric chest disorders, highlighting the role played by advanced technology. As the conventional features of most of these disorders are extremely well known, special attention is devoted to the technical aspects of the modern imaging modalities, their indications, and the diagnostic information that they supply. Individual chapters focus on chest ultrasound, nuclear medicine imaging, high-resolution chest CT, helical CT, and pediatric cardiac CT and pediatric cardiacMRI. Others are directed towards specific disorders, including congenital malformations of the chest, chest tumors, pulmonary infection, trauma, the lung in systemic diseases, the pediatric airway, foreign bodies, the thymus, and the chest wall. Without exception, the authors of this book are internationally known specialists with great expertise in the field. This book will serve as a handy, superbly illustrated reference for all who routinely image children, as well as for those who need access to information on how best to image them. (orig.)

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... a CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple ... your doctor of any recent illnesses or other medical conditions your child may have, and if there ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... the body's interior. Refinements in detector technology allow new CT scanners to obtain multiple slices in a ... reducing the need for sedation and general anesthesia. New technologies that will make even faster scanning possible ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... scanner. top of page How does the procedure work? In many ways, CT scanning is like other ... you and/or your child remember to tell health care providers in the future. If the contrast ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... scanner. top of page How does the procedure work? In many ways, CT scanning is like other ... the best way to see if treatment is working or if a finding is stable or changed ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... it is possible, every effort is made to limit the amount of radiation children may receive from ... CT scanner or may be over the weight limit—usually 450 pounds—for the moving table. Other ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... in CT scans should have no immediate side effects. Risks The risk of serious allergic reaction to contrast materials that contain iodine is rare in children, and almost always mild, and radiology departments are ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... may find the taste mildly unpleasant even if mixed with soda or juice; however, most patients can ... Sometimes ultrasound is substituted for CT as a method of imaging in these procedures in children. A ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... of important organs in the abdomen including the liver, kidney and spleen. CT is sometimes used to: ... there is a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these ...

Children's (Pediatric) CT (Computed Tomography)

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Children's (Pediatric) CT (Computed Tomography)

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Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... benefits vs. risks? Benefits Using a multidetector CT unit to examine children is faster than the older ... clearly needed. Another strategy is to consider other tests, such as MRI or ultrasound which might give ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... remember to tell health care providers in the future. If the contrast material is swallowed, your child ... Sometimes ultrasound is substituted for CT as a method of imaging in these procedures in children. A ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... for the chest x-ray, CT is the most commonly used imaging procedure for evaluating the chest. ... scanning, especially if the chest is being scanned. Most children older than six years are able to ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... is the procedure performed? The technologist begins by positioning the patient on the CT examination table, usually ... encourage your child to report any discomfort during positioning because it is important to keep very still ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... tissues show up in shades of gray and air appears black. With CT scanning, numerous x-ray ... determines that the images are of high enough quality for the radiologist to read. top of page ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... her during the imaging process. The technologist will leave the room to perform the CT scan. However, ... are sometimes the best way to see if treatment is working or if a finding is stable ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... scanner is typically a large machine with a hole, or short tunnel, in the center. A moveable ... up in shades of gray and air appears black. With CT scanning, numerous x-ray beams and ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost- ... to protect the welfare of your child, including close monitoring. Because children are more sensitive to radiation, ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... through the body, recording an image on photographic film or a special image recording plate . Bones appear ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... and blood vessels. It may be used to help diagnose abdominal pain or evaluate for injury after ... uses of the procedure? CT is used to help diagnose a wide range of conditions due to ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... children. top of page What are some common uses of the procedure? CT is used to help ... is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... or thyroid problems. Any of these conditions may influence the decision on whether contrast material will be ... bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... CT of the chest is used to evaluate: complications from infections such as pneumonia a tumor that ... radiation dose. There always is a risk of complications from general anesthesia or sedation. Every measure will ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... radiation children may receive from a CT scan. One of the best ways of limiting radiation exposure ... or pediatrician and the radiologist will decide which type of examination is best for your child. top ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... a gown. You may be instructed to withhold food or drink beforehand, especially if sedation or anesthesia ... CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple images ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... be necessary. Your doctor will explain the exact reason why another exam is requested. Sometimes a follow- ... fine tune" the CT settings based on the reason for the exam, the body area being examined, ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... problems. Any of these conditions may influence the decision on whether contrast material will be given to ... unlike MRI. CT imaging provides real-time imaging, making it a good tool for guiding minimally invasive ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... cause cancer is debatable but because it is possible, every effort is made to limit the amount ... to restrict the area scanned as much as possible and to "fine tune" the CT settings based ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... internal organs, bones, soft tissues and blood vessels. It may be used to help diagnose abdominal pain ... evaluate blood vessels throughout the body. With CT, it is possible to obtain very detailed pictures of ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... as a CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces ... lowest radiation dose that will provide the needed diagnostic information. The benefit of an accurate diagnosis far ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... children. top of page What are some common uses of the procedure? CT is used to help ... community, you can search the ACR-accredited facilities database . This website does not provide cost information. The ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... scanner. top of page How does the procedure work? In many ways, CT scanning is like other ... For children this means shorter imaging times and less time required to hold still in order to ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... the scan although they may need coaching and practice. Younger children may not be able to hold ... can be performed if you have an implanted medical device of any kind, unlike MRI. CT imaging ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... so that the x-ray beam follows a spiral path. A special computer program processes this series ... Sometimes ultrasound is substituted for CT as a method of imaging in these procedures in children. A ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... view of the body's interior. Refinements in detector technology allow new CT scanners to obtain multiple slices ... the need for sedation and general anesthesia. New technologies that will make even faster scanning possible are ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... a CT scan can be reformatted in multiple planes, and can even generate three-dimensional images. These ... child may have, and if there is a history of heart disease, asthma, diabetes, kidney disease or ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... there is a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these ... radiation children may receive from a CT scan. One of the best ways of limiting radiation exposure ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... Sometimes ultrasound is substituted for CT as a method of imaging in these procedures in children. A ... 450 pounds—for the moving table. Other imaging methods such as ultrasound or magnetic resonance (MR) imaging ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... important organs in the abdomen including the liver, kidney and spleen. CT is sometimes used to: diagnose ... is a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... lives. CT has been shown to be a cost-effective imaging tool for a wide range of ... accredited facilities database . This website does not provide cost information. The costs for specific medical imaging tests, ...

Children's (Pediatric) CT (Computed Tomography)

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Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... scanner. top of page How does the procedure work? In many ways, CT scanning is like other ... six years are able to hold their breath long enough to complete the scan although they may ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... abdominal tumors or birth defects In the pelvic region, CT scans can help: detect cysts or tumors ... tests, treatments and procedures may vary by geographic region. Discuss the fees associated with your prescribed procedure ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... scanner. top of page How does the procedure work? In many ways, CT scanning is like other ... that the patient needs to lie still is reduced. Though the scanning itself causes no pain, your ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... scanner. top of page How does the procedure work? In many ways, CT scanning is like other ... patient, as the mild discomfort will not last long. When your child enters the scanner, special lights ...

Robot-assisted procedures in pediatric neurosurgery.

Science.gov (United States)

De Benedictis, Alessandro; Trezza, Andrea; Carai, Andrea; Genovese, Elisabetta; Procaccini, Emidio; Messina, Raffaella; Randi, Franco; Cossu, Silvia; Esposito, Giacomo; Palma, Paolo; Amante, Paolina; Rizzi, Michele; Marras, Carlo Efisio

2017-05-01

OBJECTIVE During the last 3 decades, robotic technology has rapidly spread across several surgical fields due to the continuous evolution of its versatility, stability, dexterity, and haptic properties. Neurosurgery pioneered the development of robotics, with the aim of improving the quality of several procedures requiring a high degree of accuracy and safety. Moreover, robot-guided approaches are of special interest in pediatric patients, who often have altered anatomy and challenging relationships between the diseased and eloquent structures. Nevertheless, the use of robots has been rarely reported in children. In this work, the authors describe their experience using the ROSA device (Robotized Stereotactic Assistant) in the neurosurgical management of a pediatric population. METHODS Between 2011 and 2016, 116 children underwent ROSA-assisted procedures for a variety of diseases (epilepsy, brain tumors, intra- or extraventricular and tumor cysts, obstructive hydrocephalus, and movement and behavioral disorders). Each patient received accurate preoperative planning of optimal trajectories, intraoperative frameless registration, surgical treatment using specific instruments held by the robotic arm, and postoperative CT or MR imaging. RESULTS The authors performed 128 consecutive surgeries, including implantation of 386 electrodes for stereo-electroencephalography (36 procedures), neuroendoscopy (42 procedures), stereotactic biopsy (26 procedures), pallidotomy (12 procedures), shunt placement (6 procedures), deep brain stimulation procedures (3 procedures), and stereotactic cyst aspiration (3 procedures). For each procedure, the authors analyzed and discussed accuracy, timing, and complications. CONCLUSIONS To the best their knowledge, the authors present the largest reported series of pediatric neurosurgical cases assisted by robotic support. The ROSA system provided improved safety and feasibility of minimally invasive approaches, thus optimizing the surgical

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... create detailed images of your child’s internal organs, bones, soft tissues and blood vessels. It may be ... CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide greater detail ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... of the body, in a shorter period of time. Modern CT scanners are so fast that they can scan through large sections of the body in just a few seconds. Such speed is beneficial for ...

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... scanning is painless, noninvasive and accurate. A major advantage of CT is its ability to image bone, ... us improve RadiologyInfo.org by taking our brief survey: Survey Do you have a personal story about ...

Overview of CT technologies for children

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Frush, Donald P. [Duke University Medical Center, Department of Radiology, Box 3808, Durham, NC (United States)

2014-10-15

Many technical advances in CT have reduced radiation exposure in children and adults. These advances in technology should be used in conjunction with CT techniques such as appropriate patient preparation and intravenous contrast media administration to maximize dose management and image quality. This article summarizes current dose reduction technologies for pediatric CT, noting ranges of dose reduction as well as potential limitations. Discussion includes some of the elusive aspects of assessing image quality and the need for developing personalized CT. (orig.)

Overview of CT technologies for children

International Nuclear Information System (INIS)

Frush, Donald P.

2014-01-01

Many technical advances in CT have reduced radiation exposure in children and adults. These advances in technology should be used in conjunction with CT techniques such as appropriate patient preparation and intravenous contrast media administration to maximize dose management and image quality. This article summarizes current dose reduction technologies for pediatric CT, noting ranges of dose reduction as well as potential limitations. Discussion includes some of the elusive aspects of assessing image quality and the need for developing personalized CT. (orig.)

MO-DE-204-04: Dose Optimization in CT: Trends and Motivation in the US

International Nuclear Information System (INIS)

Kofler, J.

2016-01-01

The main topic of the session is to show how dose optimization is being implemented in various regions of the world, including Europe, Australia, North America and other regions. A multi-national study conducted under International Atomic Energy Agency (IAEA) across more than 50 less resourced countries gave insight into patient radiation doses and safety practices in CT, mammography, radiography and interventional procedures, both for children and adults. An important outcome was the capability development on dose assessment and management. An overview of recent European projects related to CT radiation dose and optimization both to adults and children will be presented. Existing data on DRLs together with a European methodology proposed on establishing and using DRLs for paediatric radiodiagnostic imaging and interventional radiology practices will be shown. Compared with much of Europe at least, many Australian imaging practices are relatively new to the task of diagnostic imaging dose optimisation. In 2008 the Australian Government prescribed a requirement to periodically compare patient radiation doses with diagnostic reference levels (DRLs), where DRLs have been established. Until recently, Australia had only established DRLs for computed tomography (CT). Regardless, both professional society and individual efforts to improved data collection and develop optimisation strategies across a range of modalities continues. Progress in this field, principally with respect to CT and interventional fluoroscopy will be presented. In the US, dose reduction and optimization efforts for computed tomography have been promoted and mandated by several organizations and accrediting entities. This presentation will cover the general motivation, implementation, and implications of such efforts. Learning Objectives: Understand importance of the dose optimization in Diagnostic Radiology. See how this goal is achieved in different regions of the World. Learn about the global trend

MO-DE-204-04: Dose Optimization in CT: Trends and Motivation in the US

Energy Technology Data Exchange (ETDEWEB)

Kofler, J. [Mayo Clinic (United States)

2016-06-15

The main topic of the session is to show how dose optimization is being implemented in various regions of the world, including Europe, Australia, North America and other regions. A multi-national study conducted under International Atomic Energy Agency (IAEA) across more than 50 less resourced countries gave insight into patient radiation doses and safety practices in CT, mammography, radiography and interventional procedures, both for children and adults. An important outcome was the capability development on dose assessment and management. An overview of recent European projects related to CT radiation dose and optimization both to adults and children will be presented. Existing data on DRLs together with a European methodology proposed on establishing and using DRLs for paediatric radiodiagnostic imaging and interventional radiology practices will be shown. Compared with much of Europe at least, many Australian imaging practices are relatively new to the task of diagnostic imaging dose optimisation. In 2008 the Australian Government prescribed a requirement to periodically compare patient radiation doses with diagnostic reference levels (DRLs), where DRLs have been established. Until recently, Australia had only established DRLs for computed tomography (CT). Regardless, both professional society and individual efforts to improved data collection and develop optimisation strategies across a range of modalities continues. Progress in this field, principally with respect to CT and interventional fluoroscopy will be presented. In the US, dose reduction and optimization efforts for computed tomography have been promoted and mandated by several organizations and accrediting entities. This presentation will cover the general motivation, implementation, and implications of such efforts. Learning Objectives: Understand importance of the dose optimization in Diagnostic Radiology. See how this goal is achieved in different regions of the World. Learn about the global trend

Pediatric Emergency Care Applied Research Network head injuryprediction rules: on the basis of cost and effectiveness

Science.gov (United States)

Gökharman, Fatma Dilek; Aydın, Sonay; Fatihoğlu, Erdem; Koşar, Pınar Nercis

2017-12-19

Background/aim: Head injuries are commonly seen in the pediatric population. Noncontrast enhanced cranial CT is the method of choice to detect possible traumatic brain injury (TBI). Concerns about ionizing radiation exposure make the evaluation more challenging. The aim of this study was to evaluate the effectiveness of the Pediatric Emergency Care Applied Research Network (PECARN) rules in predicting clinically important TBI and to determine the amount of medical resource waste and unnecessary radiation exposure.Materials and methods: This retrospective study included 1041 pediatric patients presented to the emergency department. The patients were divided into subgroups of "appropriate for cranial CT", "not appropriate for cranial CT" and "cranial CT/observation of patient; both are appropriate". To determine the effectiveness of the PECARN rules, data were analyzed according to the presence of pathological findings Results: "Appropriate for cranial CT" results can predict pathology presence 118,056-fold compared to the "not appropriate for cranial CT" results. With "cranial CT/observation of patient; both are appropriate" results, pathology presence was predicted 11,457-fold compared to "not appropriate for cranial CT" results.Conclusion: PECARN rules can predict pathology presence successfully in pediatric TBI. Using PECARN can decrease resource waste and exposure to ionizing radiation.

Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... its ability to image bone, soft tissue and blood vessels all at the same time. Unlike conventional x-rays, CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

Optimal CT scanning parameters for commonly used tumor ablation applicators

International Nuclear Information System (INIS)

Eltorai, Adam E.M.; Baird, Grayson L.; Monu, Nicholas; Wolf, Farrah; Seidler, Michael; Collins, Scott; Kim, Jeomsoon; Dupuy, Damian E.

2017-01-01

Highlights: • This study aimed to determine optimal scanning parameters for commonly-used tumor ablation applicators. • The findings illustrate the overall interaction of the effects of kVp, ASiR, and reconstruction algorithm within and between probes, so that radiologists may easily reference optimal imaging performance. • Optimum combinations for each probe are provided. - Abstract: Purpose: CT-beam hardening artifact can make tumor margin visualization and its relationship to the ablation applicator tip challenging. To determine optimal scanning parameters for commonly-used applicators. Materials and methods: Applicators were placed in ex-vivo cow livers with implanted mock tumors, surrounded by bolus gel. Various CT scans were performed at 440 mA with 5 mm thickness changing kVp, scan time, ASiR, scan type, pitch, and reconstruction algorithm. Four radiologists blindly scored the images for image quality and artifact quantitatively. Results: A significant relationship between probe, kVp level, ASiR level, and reconstruction algorithm was observed concerning both image artifact and image quality (both p = <0.0001). Specifically, there are certain combinations of kVp, ASiR, and reconstruction algorithm that yield better images than other combinations. In particular, one probe performed equivalently or better than any competing probe considered here, regardless of kVp, ASiR, and reconstruction algorithm combination. Conclusion: The findings illustrate the overall interaction of the effects of kVp, ASiR, and reconstruction algorithm within and between probes, so that radiologists may easily reference optimal imaging performance for a certain combinations of kVp, ASiR, reconstruction algorithm and probes at their disposal. Optimum combinations for each probe are provided.

Optimal CT scanning parameters for commonly used tumor ablation applicators

Energy Technology Data Exchange (ETDEWEB)

Eltorai, Adam E.M. [Warren Alpert Medical School of Brown University (United States); Baird, Grayson L. [Department of Diagnostic Imaging (United States); Warren Alpert Medical School of Brown University (United States); Lifespan Biostatistics Core (United States); Rhode Island Hospital (United States); Monu, Nicholas; Wolf, Farrah; Seidler, Michael [Department of Diagnostic Imaging (United States); Warren Alpert Medical School of Brown University (United States); Rhode Island Hospital (United States); Collins, Scott [Department of Diagnostic Imaging (United States); Rhode Island Hospital (United States); Kim, Jeomsoon [Department of Medical Physics (United States); Rhode Island Hospital (United States); Dupuy, Damian E., E-mail: ddupuy@comcast.net [Department of Diagnostic Imaging (United States); Warren Alpert Medical School of Brown University (United States); Rhode Island Hospital (United States)

2017-04-15

Highlights: • This study aimed to determine optimal scanning parameters for commonly-used tumor ablation applicators. • The findings illustrate the overall interaction of the effects of kVp, ASiR, and reconstruction algorithm within and between probes, so that radiologists may easily reference optimal imaging performance. • Optimum combinations for each probe are provided. - Abstract: Purpose: CT-beam hardening artifact can make tumor margin visualization and its relationship to the ablation applicator tip challenging. To determine optimal scanning parameters for commonly-used applicators. Materials and methods: Applicators were placed in ex-vivo cow livers with implanted mock tumors, surrounded by bolus gel. Various CT scans were performed at 440 mA with 5 mm thickness changing kVp, scan time, ASiR, scan type, pitch, and reconstruction algorithm. Four radiologists blindly scored the images for image quality and artifact quantitatively. Results: A significant relationship between probe, kVp level, ASiR level, and reconstruction algorithm was observed concerning both image artifact and image quality (both p = <0.0001). Specifically, there are certain combinations of kVp, ASiR, and reconstruction algorithm that yield better images than other combinations. In particular, one probe performed equivalently or better than any competing probe considered here, regardless of kVp, ASiR, and reconstruction algorithm combination. Conclusion: The findings illustrate the overall interaction of the effects of kVp, ASiR, and reconstruction algorithm within and between probes, so that radiologists may easily reference optimal imaging performance for a certain combinations of kVp, ASiR, reconstruction algorithm and probes at their disposal. Optimum combinations for each probe are provided.

Pediatric thoracic CT angiography at 70 kV: a phantom study to investigate the effects on image quality and radiation dose

International Nuclear Information System (INIS)

MacDougall, Robert D.; Kleinman, Patricia L.; Lee, Edward Y.; Yu, Lifeng

2016-01-01

Studies have demonstrated that 70-kilovolt (kV) imaging enhances the contrast of iodine, potentially affording a reduction in radiation dose while maintaining the contrast-to-noise ratio (CNR). There is a maximum amount of image noise beyond which increased contrast does not improve structure visualization. Thus, noise should be constrained during protocol optimization. This phantom study investigated the effect of 70-kV imaging for pediatric thoracic CT angiography on image quality and radiation dose in a pediatric population when a noise constraint was considered. We measured contrast and noise using anthropomorphic thoracic phantoms ranging in size from newborn age equivalent to 10-year-old age equivalent. We inserted contrast rods into the phantoms to simulate injected contrast material used in a CT angiography study. The image-quality metric ''iodine CNR with a noise constraint'' was used to determine the relative dose factor for each phantom size, kV setting (70-140 kV) and noise constraint (1.00-1.20). A noise constraint of 1.20 indicates that noise should not increase by more than 20% of the noise level in images performed at the reference kV, selected to be 80 kV in this study. The relative dose factor can be applied to the original dose obtained at 80 kV in order to maintain iodine CNR with the noise constraint. A relative dose factor <1.0 indicates potential for dose reduction while a relative dose factor >1.0 indicates a dose penalty. Iodine contrast was highest for 70 kV and decreased with higher kV settings for all phantom sizes. The relative dose factor at 70 kV was <1.0 for all noise constraint >1.0, indicating potential for dose reduction, for the newborn, 1-year-old and 5-year-old age-equivalent phantom sizes. For the 10-year-old age-equivalent phantom, relative dose factor at 70 kV=1.22, 1.11, 1.01, 0.92 and 0.83 for noise constraint=1.00, 1.05, 1.10, 1.15, 1.20, respectively, indicating a dose penalty for noise constraint �

Optimization of hybrid iterative reconstruction level and evaluation of image quality and radiation dose for pediatric cardiac computed tomography angiography

Energy Technology Data Exchange (ETDEWEB)

Yang, Lin; Liang, Changhong [Southern Medical University, Guangzhou (China); Guangdong Academy of Medical Sciences, Dept. of Radiology, Guangdong General Hospital, Guangzhou (China); Zhuang, Jian [Guangdong Academy of Medical Sciences, Dept. of Cardiac Surgery, Guangdong Cardiovascular Inst., Guangdong Provincial Key Lab. of South China Structural Heart Disease, Guangdong General Hospital, Guangzhou (China); Huang, Meiping [Guangdong Academy of Medical Sciences, Dept. of Radiology, Guangdong General Hospital, Guangzhou (China); Guangdong Academy of Medical Sciences, Dept. of Catheterization Lab, Guangdong Cardiovascular Inst., Guangdong Provincial Key Lab. of South China Structural Heart Disease, Guangdong General Hospital, Guangzhou (China); Liu, Hui [Guangdong Academy of Medical Sciences, Dept. of Radiology, Guangdong General Hospital, Guangzhou (China)

2017-01-15

Hybrid iterative reconstruction can reduce image noise and produce better image quality compared with filtered back-projection (FBP), but few reports describe optimization of the iteration level. We optimized the iteration level of iDose{sup 4} and evaluated image quality for pediatric cardiac CT angiography. Children (n = 160) with congenital heart disease were enrolled and divided into full-dose (n = 84) and half-dose (n = 76) groups. Four series were reconstructed using FBP, and iDose{sup 4} levels 2, 4 and 6; we evaluated subjective quality of the series using a 5-grade scale and compared the series using a Kruskal-Wallis H test. For FBP and iDose{sup 4}-optimal images, we compared contrast-to-noise ratios (CNR) and size-specific dose estimates (SSDE) using a Student's t-test. We also compared diagnostic-accuracy of each group using a Kruskal-Wallis H test. Mean scores for iDose{sup 4} level 4 were the best in both dose groups (all P < 0.05). CNR was improved in both groups with iDose{sup 4} level 4 as compared with FBP. Mean decrease in SSDE was 53% in the half-dose group. Diagnostic accuracy for the four datasets were in the range 92.6-96.2% (no statistical difference). iDose{sup 4} level 4 was optimal for both the full- and half-dose groups. Protocols with iDose{sup 4} level 4 allowed 53% reduction in SSDE without significantly affecting image quality and diagnostic accuracy. (orig.)

Children's (Pediatric) CT (Computed Tomography)

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Children's (Pediatric) CT (Computed Tomography)

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Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Using a multidetector CT unit to examine children ... that will provide the needed diagnostic information. The benefit of an accurate diagnosis far outweighs the risk. ...

Spectral CT metal artifact reduction with an optimization-based reconstruction algorithm

Science.gov (United States)

Gilat Schmidt, Taly; Barber, Rina F.; Sidky, Emil Y.

2017-03-01

Metal objects cause artifacts in computed tomography (CT) images. This work investigated the feasibility of a spectral CT method to reduce metal artifacts. Spectral CT acquisition combined with optimization-based reconstruction is proposed to reduce artifacts by modeling the physical effects that cause metal artifacts and by providing the flexibility to selectively remove corrupted spectral measurements in the spectral-sinogram space. The proposed Constrained `One-Step' Spectral CT Image Reconstruction (cOSSCIR) algorithm directly estimates the basis material maps while enforcing convex constraints. The incorporation of constraints on the reconstructed basis material maps is expected to mitigate undersampling effects that occur when corrupted data is excluded from reconstruction. The feasibility of the cOSSCIR algorithm to reduce metal artifacts was investigated through simulations of a pelvis phantom. The cOSSCIR algorithm was investigated with and without the use of a third basis material representing metal. The effects of excluding data corrupted by metal were also investigated. The results demonstrated that the proposed cOSSCIR algorithm reduced metal artifacts and improved CT number accuracy. For example, CT number error in a bright shading artifact region was reduced from 403 HU in the reference filtered backprojection reconstruction to 33 HU using the proposed algorithm in simulation. In the dark shading regions, the error was reduced from 1141 HU to 25 HU. Of the investigated approaches, decomposing the data into three basis material maps and excluding the corrupted data demonstrated the greatest reduction in metal artifacts.

Optimized energy of spectral CT for infarct imaging: Experimental validation with human validation.

Science.gov (United States)

Sandfort, Veit; Palanisamy, Srikanth; Symons, Rolf; Pourmorteza, Amir; Ahlman, Mark A; Rice, Kelly; Thomas, Tom; Davies-Venn, Cynthia; Krauss, Bernhard; Kwan, Alan; Pandey, Ankur; Zimmerman, Stefan L; Bluemke, David A

Late contrast enhancement visualizes myocardial infarction, but the contrast to noise ratio (CNR) is low using conventional CT. The aim of this study was to determine if spectral CT can improve imaging of myocardial infarction. A canine model of myocardial infarction was produced in 8 animals (90-min occlusion, reperfusion). Later, imaging was performed after contrast injection using CT at 90 kVp/150 kVpSn. The following reconstructions were evaluated: Single energy 90 kVp, mixed, iodine map, multiple monoenergetic conventional and monoenergetic noise optimized reconstructions. Regions of interest were measured in infarct and remote regions to calculate contrast to noise ratio (CNR) and Bhattacharya distance (a metric of the differentiation between regions). Blinded assessment of image quality was performed. The same reconstruction methods were applied to CT scans of four patients with known infarcts. For animal studies, the highest CNR for infarct vs. myocardium was achieved in the lowest keV (40 keV) VMo images (CNR 4.42, IQR 3.64-5.53), which was superior to 90 kVp, mixed and iodine map (p = 0.008, p = 0.002, p energy in conjunction with noise-optimized monoenergetic post-processing improves CNR of myocardial infarct delineation by approximately 20-25%. Published by Elsevier Inc.

Optimal Pain Assessment in Pediatric Rehabilitation: Implementation of a Nursing Guideline.

Science.gov (United States)

Kingsnorth, Shauna; Joachimides, Nick; Krog, Kim; Davies, Barbara; Higuchi, Kathryn Smith

2015-12-01

In Ontario, Canada, the Registered Nurses' Association promotes a Best Practice Spotlight Organization initiative to enhance evidence-based practice. Qualifying organizations are required to implement strategies, evaluate outcomes, and sustain practices aligned with nursing clinical practice guidelines. This study reports on the development and evaluation of a multifaceted implementation strategy to support adoption of a nursing clinical practice guideline on the assessment and management of acute pain in a pediatric rehabilitation and complex continuing care hospital. Multiple approaches were employed to influence behavior, attitudes, and awareness around optimal pain practice (e.g., instructional resources, electronic reminders, audits, and feedback). Four measures were introduced to assess pain in communicating and noncommunicating children as part of a campaign to treat pain as the fifth vital sign. A prospective repeated measures design examined survey and audit data to assess practice aligned with the guideline. The Knowledge and Attitudes Survey (KNAS) was adapted to ensure relevance to the local practice setting and was assessed before and after nurses' participation in three education modules. Audit data included client demographics and pain scores assessed annually over a 3-year window. A final sample of 69 nurses (78% response rate) provided pre-/post-survey data. A total of 108 pediatric surgical clients (younger than 19 years) contributed audit data across the three collection cycles. Significant improvements in nurses' knowledge, attitudes, and behaviors related to optimal pain care for children with disabilities were noted following adoption of the pain clinical practice guideline. Targeted guideline implementation strategies are central to supporting optimal pain practice. Copyright © 2015 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

Children's (Pediatric) Nuclear Medicine

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Full Text Available ... The teddy bear denotes child-specific content. Related Articles and Media General Nuclear Medicine Children's (Pediatric) CT ( ... About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2018 Radiological Society of ...

Ultrasound Accuracy in Diagnosing Appendicitis in Obese Pediatric Patients.

Science.gov (United States)

Love, Bryan E; Camelo, Monica; Nouri, Sarvenaz; Kriger, Diego; Ludi, Daniel; Nguyen, Henry

2017-10-01

The use of ultrasound to diagnose appendicitis in pediatric patients has been growing with the improvement of ultrasound technology and operator skills, but its utility in the increasingly obese pediatric population has not been thoroughly investigated. A retrospective review of all pediatric (≤18 years old) patients with appendicitis who were admitted at a single hospital from 2014 to 2016 was conducted. Patients were stratified into body mass index (BMI) percentile categories based on the centers for disease control guidelines. Comparisons were then made. There were 231 patients with an average BMI percentile of 72.6; 99 (42.9%) who had an ultrasound, of which 54 (54.5%) were positive for acute appendicitis, whereas 43 (43.4%) were nondiagnostic. In patients who had a nondiagnostic ultrasound, 37 had a CT demonstrating acute appendicitis. These were compared with 123 patients who had CT alone demonstrating acute appendicitis. The CT-only group was older (12 vs 9, P appendicitis.

Thermoluminescent dosimetry in computed tomography for pediatric patients; Dosimetria termoluminiscente en tomografia computada para pacientes pediatricos

Energy Technology Data Exchange (ETDEWEB)

Medrano S, A. C.; Medina A, O.; Hidalgo T, S.; Azorin N, J., E-mail: alicesar1993@hotmail.com [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico D. F. (Mexico)

2015-10-15

Computed tomography (CT) in conjunction with interventional radiology, is considered as high-dose radiological procedure, so the optimization of the dose is necessary. Exposure to ionizing radiation in pediatric CT is of particular interest because the children are up to 10 times more sensitive to radiation than adults, the late somatic and genetic effects of radiation. The exposure and risk associated with ionizing radiation in CT is best characterized by the absorbed dose to each organ. Thermoluminescent dosimeters of LiF: Mg, Ti are best suited for this purpose due to its characteristics such as high sensitivity, small size and its equivalence with the tissue. The results of dose measurements -in vivo- to the three types of CT studies (skull, thorax and abdomen) are presented. These results indicate that lower doses were obtained in skull study, while the highest was one of abdomen. (Author)