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Sample records for pediatric ct optimization

  1. Optimization of hybrid iterative reconstruction level in pediatric body CT.

    Science.gov (United States)

    Karmazyn, Boaz; Liang, Yun; Ai, Huisi; Eckert, George J; Cohen, Mervyn D; Wanner, Matthew R; Jennings, S Gregory

    2014-02-01

    The objective of our study was to attempt to optimize the level of hybrid iterative reconstruction (HIR) in pediatric body CT. One hundred consecutive chest or abdominal CT examinations were selected. For each examination, six series were obtained: one filtered back projection (FBP) and five HIR series (iDose(4)) levels 2-6. Two pediatric radiologists, blinded to noise measurements, independently chose the optimal HIR level and then rated series quality. We measured CT number (mean in Hounsfield units) and noise (SD in Hounsfield units) changes by placing regions of interest in the liver, muscles, subcutaneous fat, and aorta. A mixed-model analysis-of-variance test was used to analyze correlation of noise reduction with the optimal HIR level compared with baseline FBP noise. One hundred CT examinations were performed of 88 patients (52 females and 36 males) with a mean age of 8.5 years (range, 19 days-18 years); 12 patients had both chest and abdominal CT studies. Radiologists agreed to within one level of HIR in 92 of 100 studies. The mean quality rating was significantly higher for HIR than FBP (3.6 vs 3.3, respectively; p optimal HIR level was used (p optimal for most studies. The optimal HIR level was less effective in reducing liver noise in children with lower baseline noise.

  2. Optimization of pediatric examinations in a multislice helical CT

    International Nuclear Information System (INIS)

    Ombada, T. H. A.

    2010-12-01

    Radiological protection of pediatric patients undergoing medical imaging procedures involving ionizing radiation has always received special attention. This is due to the fact that children have higher radiation sensitivity and increased likelihood for radiation-induced cancer manifesting in many more years of their life than adults. In computed tomography (CT), such attention is more important because of the potential of relatively higher radiation doses during these procedures. Such high doses are possible with technological developments where volume scanning using faster multi-slice CT systems is now preferred to conventional CT equipment. The task of this study is to assess the optimization of paediatric doses in multi-slice CT examinations. It was carried out in Alrebat University Hospital for 31 pediatric patients, 43 examinations (27 head examination and 16 body (chest, abdomen and pelvis) examinations). Data were collected for scan parameters (kV, m As, pitch, scan length, number of slices and slice thickness) and doses displayed in monitor (CTDI v ol and DLP) for head examinations and body (chest, abdomen and pelvis) examinations. For head CT, displayed CTDI v ol ranged from 1.56 to 69.12 mGy, calculated value from 2.10 to 70.93 mGy. Displayed DLP ranged from 53 to 1817 mGy.cm, calculated from 95.30 to 1532.16 mGy. cm. For body examination, the range of displayed CTDI from 1.63 to 3.92 mGy, calculated value from 2.22 to 5.34 mGy. Displayed DLP ranged from 34 to 194 mGy.cm, for calculated from 45.89 to 161.98 mGy. cm. The calculated values are in agreement with reference study dose values although there are some high values in this study for some examinations, this variation or difference may attribute to variation in pediatric ages (9 days- 15 years), scan length and m As values. There is variation between calculated and displayed values. more optimization for CT doses is needed. (Author)

  3. Optimization of pediatric examinations in a multislice helical CT

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    Ombada, T H. A. [Atomic Energy Council, Sudan Academy of Sciences (SAS), Khartoum (Sudan)

    2010-12-15

    Radiological protection of pediatric patients undergoing medical imaging procedures involving ionizing radiation has always received special attention. This is due to the fact that children have higher radiation sensitivity and increased likelihood for radiation-induced cancer manifesting in many more years of their life than adults. In computed tomography (CT), such attention is more important because of the potential of relatively higher radiation doses during these procedures. Such high doses are possible with technological developments where volume scanning using faster multi-slice CT systems is now preferred to conventional CT equipment. The task of this study is to assess the optimization of paediatric doses in multi-slice CT examinations. It was carried out in Alrebat University Hospital for 31 pediatric patients, 43 examinations (27 head examination and 16 body (chest, abdomen and pelvis) examinations). Data were collected for scan parameters (kV, m As, pitch, scan length, number of slices and slice thickness) and doses displayed in monitor (CTDI{sub v}ol and DLP) for head examinations and body (chest, abdomen and pelvis) examinations. For head CT, displayed CTDI{sub v}ol ranged from 1.56 to 69.12 mGy, calculated value from 2.10 to 70.93 mGy. Displayed DLP ranged from 53 to 1817 mGy.cm, calculated from 95.30 to 1532.16 mGy. cm. For body examination, the range of displayed CTDI from 1.63 to 3.92 mGy, calculated value from 2.22 to 5.34 mGy. Displayed DLP ranged from 34 to 194 mGy.cm, for calculated from 45.89 to 161.98 mGy. cm. The calculated values are in agreement with reference study dose values although there are some high values in this study for some examinations, this variation or difference may attribute to variation in pediatric ages (9 days- 15 years), scan length and m As values. There is variation between calculated and displayed values. more optimization for CT doses is needed. (Author)

  4. TH-B-207B-01: Optimizing Pediatric CT in the Emergency Department

    International Nuclear Information System (INIS)

    Dodge, C.

    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

  5. TH-B-207B-01: Optimizing Pediatric CT in the Emergency Department

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    Dodge, C. [Texas Children’s Hospital (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.

  6. 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)

  7. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is a fast, painless exam that uses special ... the limitations of Children's CT? What is Children's CT? Computed tomography, more commonly known as a CT or CAT ...

  8. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is ... a CT scan. View full size with caption Pediatric Content Some imaging tests and treatments have special ...

  9. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... News Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) ... are the limitations of Children's CT? What is Children's CT? Computed tomography, more commonly known as a ...

  10. 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

  11. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is a fast, painless exam that uses ... of Children's CT? What is Children's CT? Computed tomography, more commonly known as a CT or CAT ...

  12. Clinical application of 'Justification' and 'Optimization' principle of ALARA in pediatric CT imaging: "How many children can be protected from unnecessary radiation?".

    Science.gov (United States)

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

    2015-09-01

    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 protected from harmful radiation exposure if 'Justification' and 'Optimization' principles of ALARA are applied before obtaining CT imaging in a developing country. This can save children from potential radiation risks including development of brain cancer and leukemia. Consecutive 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 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. A total of 1302 consecutive CT request forms were received during the study period. Some of the request forms (n=86; 6.61%) had requests for more than one (multiple) anatomical regions, hence, a total of 1392 different anatomical CT requests were received. 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 protected from unnecessary or additional radiation exposure.The rates of declined or optimized CT requests from inpatient department was significantly higher than that from outpatient

  13. 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 ...

  14. 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 ...

  15. 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) ...

  16. 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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  18. 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 ...

  19. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... Children's (Pediatric) CT (Computed Tomography) Sponsored by Please note RadiologyInfo.org is not a medical facility. Please ... is further reviewed by committees from the American College of Radiology (ACR) and the Radiological Society of ...

  20. SPECT/CT in pediatric patient management

    International Nuclear Information System (INIS)

    Nadel, Helen R.

    2014-01-01

    Hybrid SPECT/CT imaging is becoming the standard of care in pediatric imaging. Indications are mainly for oncologic imaging including mIBG scintigraphy for neuroblastoma and I-123 post surgical imaging of children with thyroid carcinoma, bone scintigraphy for back pain, children referred from sports medicine and neurodevelopmentally delayed children presenting with pain symptoms. The studies provide improved diagnostic accuracy, and oncologic imaging that includes optimized CT as part of the SPECT/CT study may decrease the number of studies and sedation procedures an individual child may need. The studies, however, must be tailored on an individual basis as the addition of the CT study can increase exposure to the child and should only be performed after appropriate justification and with adherence to optimized low dose pediatric protocols. (orig.)

  1. SPECT/CT in pediatric patient management

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    Nadel, Helen R. [British Columbia Children' s Hospital, University of British Columbia, Pediatric Radiologist and Nuclear Medicine Physician, Division of Nuclear Medicine Department of Radiology, Vancouver, British Columbia (Canada)

    2014-05-15

    Hybrid SPECT/CT imaging is becoming the standard of care in pediatric imaging. Indications are mainly for oncologic imaging including mIBG scintigraphy for neuroblastoma and I-123 post surgical imaging of children with thyroid carcinoma, bone scintigraphy for back pain, children referred from sports medicine and neurodevelopmentally delayed children presenting with pain symptoms. The studies provide improved diagnostic accuracy, and oncologic imaging that includes optimized CT as part of the SPECT/CT study may decrease the number of studies and sedation procedures an individual child may need. The studies, however, must be tailored on an individual basis as the addition of the CT study can increase exposure to the child and should only be performed after appropriate justification and with adherence to optimized low dose pediatric protocols. (orig.)

  2. 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.

  3. Pediatric CT quality management and improvement program

    Energy Technology Data Exchange (ETDEWEB)

    Larson, David B.; Chan, Frandics P.; Newman, Beverley; Fleischmann, Dominik [Stanford University School of Medicine, Department of Radiology, Stanford, CA (United States); Molvin, Lior Z. [Stanford Hospital and Clinics, Stanford, CA (United States); Wang, Jia [Stanford University, Environmental Health and Safety, Stanford, CA (United States)

    2014-10-15

    Modern CT is a powerful yet increasingly complex technology that continues to rapidly evolve; optimal clinical implementation as well as appropriate quality management and improvement in CT are challenging but attainable. This article outlines the organizational structure on which a CT quality management and improvement program can be built, followed by a discussion of common as well as pediatric-specific challenges. Organizational elements of a CT quality management and improvement program include the formulation of clear objectives; definition of the roles and responsibilities of key personnel; implementation of a technologist training, coaching and feedback program; and use of an efficient and accurate monitoring system. Key personnel and roles include a radiologist as the CT director, a qualified CT medical physicist, as well as technologists with specific responsibilities and adequate time dedicated to operation management, CT protocol management and CT technologist education. Common challenges in managing a clinical CT operation are related to the complexity of newly introduced technology, of training and communication and of performance monitoring. Challenges specific to pediatric patients include the importance of including patient size in protocol and dose considerations, a lower tolerance for error in these patients, and a smaller sample size from which to learn and improve. (orig.)

  4. Pediatric CT quality management and improvement program

    International Nuclear Information System (INIS)

    Larson, David B.; Chan, Frandics P.; Newman, Beverley; Fleischmann, Dominik; Molvin, Lior Z.; Wang, Jia

    2014-01-01

    Modern CT is a powerful yet increasingly complex technology that continues to rapidly evolve; optimal clinical implementation as well as appropriate quality management and improvement in CT are challenging but attainable. This article outlines the organizational structure on which a CT quality management and improvement program can be built, followed by a discussion of common as well as pediatric-specific challenges. Organizational elements of a CT quality management and improvement program include the formulation of clear objectives; definition of the roles and responsibilities of key personnel; implementation of a technologist training, coaching and feedback program; and use of an efficient and accurate monitoring system. Key personnel and roles include a radiologist as the CT director, a qualified CT medical physicist, as well as technologists with specific responsibilities and adequate time dedicated to operation management, CT protocol management and CT technologist education. Common challenges in managing a clinical CT operation are related to the complexity of newly introduced technology, of training and communication and of performance monitoring. Challenges specific to pediatric patients include the importance of including patient size in protocol and dose considerations, a lower tolerance for error in these patients, and a smaller sample size from which to learn and improve. (orig.)

  5. 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

  6. 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 ...

  7. 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 ...

  8. 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.

  9. Pediatric thoracic CT angiography

    International Nuclear Information System (INIS)

    Frush, Donald P.; Herlong, J. Rene

    2005-01-01

    One of the principal benefits of contemporary multidetector row computed tomography (MDCT) has been the ability to obtain high-data sets for evaluation of the cardiovascular system. The benefits of the greater number of detector rows and submillimeter image thicknesses were quickly recognized and are especially advantageous in children. For example, since imaging is performed so quickly, issues with motion are minimized. This is a substantial benefit of CTA compared with MR imaging, the traditional noninvasive cross sectional modality for pediatric cardiovascular imaging. This, together with faster and more powerful computers, including improved transfer and storage capabilities, offers improved depiction of the heart, great vessels, other vasculature and adjacent intrathoracic structures in a fashion that is well accepted by clinical colleagues. In order to be successful, however, one must have an understanding of the technology and often unique technical considerations in infants and children. With this familiarity, excellent cardiovascular examinations can be performed even in the most challenging case. (orig.)

  10. 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.

  11. TH-B-207B-00: Pediatric Image Quality Optimization

    International Nuclear Information System (INIS)

    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

  12. TH-B-207B-00: Pediatric Image Quality Optimization

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  13. 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.

  14. 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.)

  15. 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

  16. Effect of staff training on radiation dose in pediatric CT

    Energy Technology Data Exchange (ETDEWEB)

    Hojreh, Azadeh, E-mail: azadeh.hojreh@meduniwien.ac.at [Medical University of Vienna, Department of Biological Imaging and Image-guided Therapy, Division of General and Paediatric Radiology, Waehringer Guertel 18–20, A-1090 Vienna (Austria); Weber, Michael, E-mail: michael.Weber@Meduniwien.Ac.At [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Division of General and Paediatric Radiology, Waehringer Guertel 18–20, A-1090 Vienna (Austria); Homolka, Peter, E-mail: peter.Homolka@Meduniwien.Ac.At [Medical University of Vienna, Centre for Medical Physics and Biomedical Engineering, Waehringer Guertel 18–20, A-1090 Vienna (Austria)

    2015-08-15

    Highlights: • Pediatric patient CT doses were compared before and after staff training. • Staff training increasing dose awareness resulted in patient dose reduction. • Application of DRL reduced number of CT's with unusually high doses. • Continuous education and training are effective regarding dose optimization. - Abstract: Objective: To evaluate the efficacy of staff training on radiation doses applied in pediatric CT scans. Methods: 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. Results: A pooled analysis of non-traumatic scans revealed a statistically significant reduction in the dose for cranial, thoracic, and abdomen/pelvis scans (p < 0.01). This trend could be demonstrated also for trunk scans, however, significance could not be established due to low patient frequencies (p > 0.05). 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). Conclusions: Staff training together with application of DRLs provide an efficient approach for optimizing radiation dose in pediatric CT practice.

  17. 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.

  18. Children's (Pediatric) CT (Computed Tomography)

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    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 ...

  19. 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 in a single rotation. These scanners, called "multislice CT" or "multidetector CT," ...

  20. Experimental study of abdominal CT scanning exposal doses adjusted on the basis of pediatric abdominal perimeter

    International Nuclear Information System (INIS)

    Wei Wenzhou; Zhu Gongsheng; Zeng Lingyan; Yin Xianglin; Yang Fuwen; Liu Changsheng

    2006-01-01

    Objective: To optimize the abdominal helical CT scanning parameters in pediatric patients and to reduce its radiation hazards. Methods: 60 canines were evenly grouped into 4 groups on the basis of pediatric abdominal perimeter, scanned with 110,150,190 and 240 mAs, and their qualities of canine CT images were analyzed. 120 pediafric patients with clinic suspected abdominal diseases were divided into 4 groups on the basis of abdominal perimeter, scanned by optimal parameters and their image qualities were analyzed. Results: After CT exposure were reduced, the percentages of total A and B were 90.9 % and 92.0 % in experimental canines and in pediatric patients, respectively. Compared with conventional CT scanning, the exposure and single slice CT dose index weighted (CTDIw) were reduced to 45.8%-79.17%. Conclusion: By adjusted the pediatric helical CT parameters basedon the of pediatric abdominal perimeter, exposure of patient to the hazards of radiation is reduced. (authors)

  1. 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.

  2. 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 ...

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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 ...

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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 ...

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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, ...

  15. 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 ...

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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 ...

  18. 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 ...

  19. 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 ...

  20. 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, ...

  1. Children's (Pediatric) CT (Computed Tomography)

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    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 ...

  2. Children's (Pediatric) CT (Computed Tomography)

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    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 ...

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    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 ...

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    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 ...

  5. 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 ...

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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 " ... To locate a medical imaging or radiation oncology provider in your community, you can search the ACR- ...

  7. 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 ...

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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) ...

  9. 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 ...

  10. 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 ...

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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 ...

  12. 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 ...

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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 ...

  14. 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 ...

  15. 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 ...

  16. 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 ...

  17. 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 ...

  18. 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 ...

  19. 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 ...

  20. 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, ...

  1. 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 ...

  2. 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, ...

  3. 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 ...

  4. 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 ...

  5. 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 ...

  6. 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 ...

  7. 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 ...

  8. 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 ...

  9. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... a follow-up exam is done because a potential abnormality needs further evaluation with additional views or ... detailed images of many types of tissue as well as the lungs, bones, and blood vessels. CT ...

  10. 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 ...

  11. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... imaging provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as ... areas of the body that sometimes are as good as or better than those obtained by CT ...

  12. 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 ...

  13. 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 ...

  14. 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 ...

  15. 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 ...

  16. 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 ...

  17. 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, ...

  18. 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 ...

  19. 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 ...

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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 ...

  1. 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 ...

  2. 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 ...

  3. 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 ...

  4. 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 ...

  5. 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 ...

  6. 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 ...

  7. 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 ...

  8. 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. ...

  9. 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 ...

  10. 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 ...

  11. 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 ...

  12. 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 ...

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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 ...

  14. 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 ...

  15. 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 ...

  16. 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 ...

  17. 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 ...

  18. 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 ...

  19. Children's (Pediatric) CT (Computed Tomography)

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    ... 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 ...

  20. 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. ...

  1. 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 ...

  2. 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, ...

  3. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... like? The CT scanner is typically a large machine with a hole, or short tunnel, in the ... of this tunnel. In the center of the machine, the x-ray tube and electronic x-ray ...

  4. 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 ...

  5. 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 ...

  6. 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 ...

  7. 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 ...

  8. 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 ...

  9. 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 ...

  10. 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.)

  11. 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 conditions may influence the decision on whether contrast material will be given to your child for the CT examination. top of page What ...

  12. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... CT (Computed Tomography) Sponsored by Please note RadiologyInfo.org is not a medical facility. Please contact your ... links: For the convenience of our users, RadiologyInfo .org provides links to relevant websites. RadiologyInfo.org , ACR ...

  13. 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 is to be used. In general, children who have recently been ill will not be sedated or anesthetized. What is Children's CT? What are some common uses ...

  14. 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 ... CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple images ...

  15. 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 used to ... CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide greater detail than traditional ...

  16. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... if there is a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may influence the decision on whether contrast material will be given to your child for the CT examination. top of page What ...

  17. 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 x-ray examinations. X-rays are a form of radiation, like light or radio waves that can be directed at the body. Different body parts absorb the x- ...

  18. 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 diagnosis ... 450 pounds—for the moving table. Other imaging methods such as ultrasound or magnetic resonance (MR) imaging can provide pictures of certain areas of the body that sometimes are ...

  19. 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.)

  20. 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.)

  1. 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)

  2. Asian consortium on radiation dose of pediatric cardiac CT (ASCI-REDCARD)

    International Nuclear Information System (INIS)

    Hui, Peter K.T.; Goo, Hyun Woo; Du, Jing; Ip, Janice J.K.; Kanzaki, Suzu; Kim, Young Jin; Kritsaneepaiboon, Supika; Lilyasari, Oktavia; Siripornpitak, Suvipaporn

    2017-01-01

    With incremental utilization of pediatric cardiac CT in congenital heart disease, it is imperative to define its current radiation dose levels in clinical practice in order to help imagers optimize CT protocols, particularly in Asia and other developing countries where CT physicists are not readily available. To evaluate current radiation dose levels and influencing factors in cardiac CT in children with congenital heart disease in Asia by conducting a retrospective multi-center, multi-vendor study. We included 1,043 pediatric cardiac CT examinations performed in 8 centers between January 2014 and December 2014 to evaluate congenital heart disease. In five weight groups, we calculated radiation dose metrics including volume CT dose index, size-specific dose estimate, dose-length product and effective dose. Age at CT exam, gender, tube voltage, scan mode, CT indication and image reconstruction algorithm were analyzed to learn whether they influenced CT radiation dose. Volume CT dose index, size-specific dose estimate, dose-length product and effective dose of pediatric cardiac CT showed variations in the range of 4.3-23.8 mGy, 4.9-17.6 mGy, 55.8-501.3 mGy circle cm and 1.5-3.2 mSv, respectively, within five weight groups. Gender, tube voltage, scan mode and cardiac function assessment significantly influenced CT radiation dose. This multi-center, multi-vendor study demonstrated variations in radiation dose metrics of pediatric cardiac CT reflecting current practice in Asia. Gender, tube voltage, scan mode and cardiac function assessment should be considered as essential radiation dose-influencing factors in developing optimal pediatric cardiac CT protocols. (orig.)

  3. Asian consortium on radiation dose of pediatric cardiac CT (ASCI-REDCARD)

    Energy Technology Data Exchange (ETDEWEB)

    Hui, Peter K.T. [Hong Kong Baptist Hospital, Department of Radiology, Hong Kong, SAR (China); Goo, Hyun Woo [University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Du, Jing [Beijing Anzhen Hospital, Capital Medical University, Department of Radiology, Beijing (China); Ip, Janice J.K. [Queen Mary Hospital, Department of Radiology, Hong Kong, SAR (China); Kanzaki, Suzu [National Cerebral and Cardiovascular Center, Department of Radiology, Osaka (Japan); Kim, Young Jin [Yonsei University, Shinchon Severance Hospital, Department of Radiology, Seoul (Korea, Republic of); Kritsaneepaiboon, Supika [Songklanagarind Hospital, Prince of Songkla University, Department of Radiology, Hat Yai (Thailand); Lilyasari, Oktavia [University of Indonesia, National Cardiovascular Center Harapan Kita, Department of Cardiology, Jakarta (Indonesia); Siripornpitak, Suvipaporn [Ramathibodi Hospital, Mahidol University, Department of Radiology, Salaya (Thailand)

    2017-07-15

    With incremental utilization of pediatric cardiac CT in congenital heart disease, it is imperative to define its current radiation dose levels in clinical practice in order to help imagers optimize CT protocols, particularly in Asia and other developing countries where CT physicists are not readily available. To evaluate current radiation dose levels and influencing factors in cardiac CT in children with congenital heart disease in Asia by conducting a retrospective multi-center, multi-vendor study. We included 1,043 pediatric cardiac CT examinations performed in 8 centers between January 2014 and December 2014 to evaluate congenital heart disease. In five weight groups, we calculated radiation dose metrics including volume CT dose index, size-specific dose estimate, dose-length product and effective dose. Age at CT exam, gender, tube voltage, scan mode, CT indication and image reconstruction algorithm were analyzed to learn whether they influenced CT radiation dose. Volume CT dose index, size-specific dose estimate, dose-length product and effective dose of pediatric cardiac CT showed variations in the range of 4.3-23.8 mGy, 4.9-17.6 mGy, 55.8-501.3 mGy circle cm and 1.5-3.2 mSv, respectively, within five weight groups. Gender, tube voltage, scan mode and cardiac function assessment significantly influenced CT radiation dose. This multi-center, multi-vendor study demonstrated variations in radiation dose metrics of pediatric cardiac CT reflecting current practice in Asia. Gender, tube voltage, scan mode and cardiac function assessment should be considered as essential radiation dose-influencing factors in developing optimal pediatric cardiac CT protocols. (orig.)

  4. 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.

  5. 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

  6. 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.

  7. 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

  8. 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.

  9. 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.)

  10. 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.

  11. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  13. 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

  14. 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)

  15. 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)

  16. 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.)

  17. 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.)

  18. Protocol optimization in chest CT scans of child

    Energy Technology Data Exchange (ETDEWEB)

    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)

  19. 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)

  20. 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.)

  1. 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.

  2. 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.)

  3. 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.)

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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

  9. 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

  10. 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.

  11. Optimization of electronic prescribing in pediatric patients

    NARCIS (Netherlands)

    Maat, B.

    2014-01-01

    Improving pediatric patient safety by preventing medication errors that may result in adverse drug events and consequent healthcare expenditure,is a worldwide challenge to healthcare. In pediatrics, reported medication error rates in general, and prescribing error rates in particular, vary between

  12. 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.)

  13. Realistic phantoms to characterize dosimetry in pediatric CT

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  14. 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

  15. 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)

  16. 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.

  17. 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.)

  18. 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

  19. 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.

  20. 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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  2. 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....

  3. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  5. 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.)

  6. 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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  8. Computed radiography dose optimization in pediatric patients

    International Nuclear Information System (INIS)

    Juste, B.; Verdu, G.; Tortosa, R.; Villaescusa, J.I.

    2008-01-01

    Radiation dose reduction in pediatric X-ray imaging is especially important because of children radiation sensitivity. For any radiographic examination performed at a fixed radiographic tube potential, the patient absorbed dose is directly proportional to the value of milliampere-seconds (mAs) selected by the operator. Nevertheless, reducing X-ray exposure has the unavoidable disadvantage of increasing the quantum noise in the resultant image. The objective of this work is to identify the minimum tube current setting required for maintaining accurate examinations, to modify, if required, the daily protocols applied at La Fe de Valencia Universitary Hospital. To accomplish this goal, a noise addition software has been developed in order to study the diagnostic accuracy as a function of reducing dose by artificially increasing the image noise. The noise addition tool has been applied to several thorax images acquired from pediatric unit to simulate new lower dose radiographies and allow medical researchers to study how lower dose affects the patient pneumonia diagnosis. (author)

  9. 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

  10. 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.)

  11. 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

  12. 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

  13. 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)

  14. 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)

  15. 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

  16. 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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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.)

  4. 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.

  5. Study of dosimetry CT in Skull for pediatric patients

    International Nuclear Information System (INIS)

    Ramos Amores, D.; Serna Berna, A.; Mata Colodro, F.; Puchades Puchades, V.

    2013-01-01

    The dose that receiving the patients in CT studies is the highest that can be received in a study of Radiology. If patients are children and we do studies with the same parameters as adults, they will receive a higher dose of radiation. This work seeks to expose the result of a dosimetric study on CT for children aged 0-15, carried out at the Hospital General Universitario de Santa Lucia in Cartagena during the year 2012. (Author)

  6. 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

  7. 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.)

  8. 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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  10. 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

  11. 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.)

  12. 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.

  13. Optimization of the dose absorbed in pediatric CT studies according to the methodology of the report n. 204 of the AAPM; Optimizacion de la dosis absorbida en estudios de TC pediatricos segun la metodologia del report n. 204 de la AAPM

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez Rodriguez, J.; Arino Gil, A.; Mateos Salvador, P.; Rodriguez, B.; Font Gelabert, J. C.

    2013-07-01

    The objective of this study is to determine the SSDE for a sample of pediatric patients grouped into 4 ranges of ages for different anatomical locations: skull, thorax, and abdomen. The SSDE values obtained are compared with the diagnostic levels of reference (NDR) for different countries 4 (expressed in CTDIvol). The goodness of the SSDE as parameter is evaluated to estimate the dose in CT. (Author)

  14. 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.

  15. 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)

  16. 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

  17. 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

  18. 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

  19. 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.

  20. Atelectasis on pediatric chest CT: comparison of sedation techniques

    International Nuclear Information System (INIS)

    Sargent, M.A.; McEachern, A.M.; Jamieson, D.H.

    1999-01-01

    Background. A change in practice at our institution resulted in increased use of anesthesia for CT scan of the chest in children who required sedation. Objective. To determine whether there is a difference in the frequency or severity of pulmonary atelectasis on CT scan in children sedated by anesthesiologists compared with children sedated by radiologists using intravenous pentobarbital. Materials and methods. Retrospective blinded review of 60 CT scans of the chest performed in 41 children. Forty-one studies in children sedated by radiologists (median age 29 months) were compared with 19 studies in children sedated by anesthesiologists (median age 25 months). Results. Atelectasis sufficient to obscure pulmonary metastases was shown in 5 of 41 (12 %) radiology sedations and 13 of 19 (68 %) anesthesiology sedations (P < 0.01). Higher grades of atelectasis were recorded in children under anesthesia (P < 0.01). Conclusion. Atelectasis is more frequent and more severe in children undergoing general anesthesia compared with intravenous pentobarbital sedation. Consideration should be given to the use of forced inspiration in children anesthetized for CT scan of the chest. (orig.)

  1. 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.

  2. 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.

  3. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. 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

  6. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  8. 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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  10. 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.)

  11. 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

  12. 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.)

  13. 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.)

  14. 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.)

  15. 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.)

  16. Extra-appendiceal findings in pediatric abdominal CT for suspected appendicitis

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  17. 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.

  18. 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.

  19. 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.

  20. 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)

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.)

  6. 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.

  7. 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.

  8. 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)

  9. 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.)

  10. 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.

  11. Assessment of the optimal temporal window for intravenous CT cholangiography

    Energy Technology Data Exchange (ETDEWEB)

    Schindera, Sebastian T.; Nelson, Rendon C.; Paulson, Erik K.; DeLong, David M.; Merkle, Elmar M. [Duke University Medical Center, Department of Radiology, P.O. Box 3808, Durham, NC (United States)

    2007-10-15

    The optimal temporal window of intravenous (IV) computed tomography (CT) cholangiography was prospectively determined. Fifteen volunteers (eight women, seven men; mean age, 38 years) underwent dynamic CT cholangiography. Two unenhanced images were acquired at the porta hepatis. Starting 5 min after initiation of IV contrast infusion (20 ml iodipamide meglumine 52%), 15 pairs of images at 5-min intervals were obtained. Attenuation of the extrahepatic bile duct (EBD) and the liver parenchyma was measured. Two readers graded visualization of the higher-order biliary branches. The first biliary opacification in the EBD occurred between 15 and 25 min (mean, 22.3 min {+-} 3.2) after initiation of the contrast agent. Biliary attenuation plateaued between the 35- and the 75-min time points. Maximum hepatic parenchymal enhancement was 18.5 HU {+-} 2.7. Twelve subjects demonstrated poor or non-visualization of higher-order biliary branches; three showed good or excellent visualization. Body weight and both biliary attenuation and visualization of the higher-order biliary branches correlated significantly (P<0.05). For peak enhancement of the biliary tree, CT cholangiography should be performed no earlier than 35 min after initiation of IV infusion. For a fixed contrast dose, superior visualization of the biliary system is achieved in subjects with lower body weight. (orig.)

  12. 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.

  13. 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)

  14. 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.)

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.)

  2. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  4. 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.)

  5. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  7. 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

  8. 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

  9. 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.)

  10. 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.)

  11. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  13. 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

  14. 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

  15. 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.

  16. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  18. 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.

  19. Task-based optimization of image reconstruction in breast CT

    Science.gov (United States)

    Sanchez, Adrian A.; Sidky, Emil Y.; Pan, Xiaochuan

    2014-03-01

    We demonstrate a task-based assessment of image quality in dedicated breast CT in order to optimize the number of projection views acquired. The methodology we employ is based on the Hotelling Observer (HO) and its associated metrics. We consider two tasks: the Rayleigh task of discerning between two resolvable objects and a single larger object, and the signal detection task of classifying an image as belonging to either a signalpresent or signal-absent hypothesis. HO SNR values are computed for 50, 100, 200, 500, and 1000 projection view images, with the total imaging radiation dose held constant. We use the conventional fan-beam FBP algorithm and investigate the effect of varying the width of a Hanning window used in the reconstruction, since this affects both the noise properties of the image and the under-sampling artifacts which can arise in the case of sparse-view acquisitions. Our results demonstrate that fewer projection views should be used in order to increase HO performance, which in this case constitutes an upper-bound on human observer performance. However, the impact on HO SNR of using fewer projection views, each with a higher dose, is not as significant as the impact of employing regularization in the FBP reconstruction through a Hanning filter.

  20. 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...

  1. 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.

  2. 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.

  3. 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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  5. {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.)

  6. 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.)

  7. Optimized contrast volume for dynamic CT angiography in renal transplant patients using a multiphase CT protocol

    International Nuclear Information System (INIS)

    Helck, A.; Bamberg, F.; Sommer, W.H.; Wessely, M.; Becker, C.; Clevert, D.A.; Notohamiprodjo, M.; Reiser, M.; Nikolaou, K.

    2011-01-01

    Objectives: To study the feasibility of an optimized multiphase renal-CT-angiography (MP-CTA) protocol in patients with history of renal transplantation compared with Doppler-ultrasound (DUS). Methods: 36 Patients underwent both DUS and time-resolved, MP-CTA (12 phases), with a mean contrast-volume of 34.4 ± 5.1 ml. Quality of MP-CTA was assessed quantitatively (vascular attenuation) and qualitatively (grades 1–4, 1 = best). For the assessment of clinical value of MP-CTA, cases were grouped into normal, macrovascular (arterial/venous) and microvascular complications (parenchymal perfusion defect). DUS served as the standard of reference. Results: Using the best of 12 phases in each patient, optimal attenuation was 353 ± 111 HU, 337 ± 98 HU and 164 ± 51 HU in the iliac arteries, renal arteries, and renal veins, respectively. Mean image quality was 1.1 ± 0.3 (n = 36) and 2.1 ± 0.6 (n = 30) for the transplant renal arteries and veins, respectively. Six renal veins were non-diagnostic in MP-CTA. In 36 patients, MP-CTA showed 13 vascular complications and 10 parenchymal perfusion defects. DUS was not assessable in eight patients. Overall, MP-CTA showed 15 cases with pathology (42%) not identifiable with DUS. The mean effective radiation dose of the MP-CTA protocol was 13.5 ± 5.2 mSv. Conclusion: MP-CTA can be sufficiently performed with reduced contrast volume at reasonable radiation dose in renal transplant patients, providing substantially higher diagnostic yield than DUS.

  8. 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

  9. 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.

  10. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  12. 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.)

  13. Multiplanar reconstructed CT images increased depiction of intracranial hemorrhages in pediatric head trauma

    Energy Technology Data Exchange (ETDEWEB)

    Langford, Stacey; Panigrahy, Ashok; Narayanan, Srikala; Hwang, Misun; Fitz, Charles; Flom, Lynda; Lee, Vincent Kyu; Zuccoli, Giulio [Children' s Hospital of Pittsburgh of UPMC, Department of Radiology, Section of Neuroradiology, Pittsburgh, PA (United States)

    2015-12-15

    The benefits of multiplanar reconstructed images (MPR) of unenhanced axial head computed tomography (CT) data have not been established in trauma patients younger than 3 years old, a population in which a reliable history and physical examination may be most difficult. We retrospectively evaluated unenhanced head CTs in pediatric trauma patients to investigate the various benefits of MPR in this age group. A total of 221 unenhanced head CTs performed for any case of head trauma (HT) on children younger than 3 years old were independently reviewed by two radiologists. Studies were reviewed first in the standard axial plane alone and then with the addition of MPR. Reviewers were asked to determine if the MPR affected the ability to make findings of hemorrhage, incidental findings, and artifacts. MPR improved the detection of hemorrhage in 14 cases (6.5 %, p-value < 0.01) and incidental findings in five cases (2.3 %, p-value < 0.05) as well as helped prove artifacts in five cases (2.3 %, p-value < 0.05). Routine use of MPR in HT patients younger than 3 years old has the potential to increase the detection of acute and incidental imaging findings. (orig.)

  14. 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...

  15. 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

  16. 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.

  17. Technology to optimize pediatric diabetes management and outcomes.

    Science.gov (United States)

    Markowitz, Jessica T; Harrington, Kara R; Laffel, Lori M B

    2013-12-01

    Technology for diabetes management is rapidly developing and changing. With each new development, there are numerous factors to consider, including medical benefits, impact on quality of life, ease of use, and barriers to use. It is also important to consider the interaction between developmental stage and technology. This review considers a number of newer diabetes-related technologies and explores issues related to their use in the pediatric diabetes population (including young adults), with a focus on psychosocial factors. Areas include trend technology in blood glucose monitoring, continuous glucose monitoring, sensor-augmented insulin pumps and low glucose suspend functions, internet applications including videoconferencing, mobile applications (apps), text messaging, and online gaming.

  18. 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.

  19. 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.

  20. Central nervous system PET-CT imaging reveals regional impairments in pediatric patients with Wolfram syndrome.

    Directory of Open Access Journals (Sweden)

    Agnieszka Zmyslowska

    Full Text Available Wolfram syndrome (WFS is inherited as an autosomal recessive disease with main clinical features of diabetes mellitus, optic atrophy, diabetes insipidus and deafness. However, various neurological defects may also be detected. The aim of this study was to evaluate aspects of brain structure and function using PET-CT (positron emission tomography and computed tomography and MRI (magnetic resonance imaging in pediatric patients with WFS. Regional changes in brain glucose metabolism were measured using standardized uptake values (SUVs based on images of (18F fluorodeoxyglucose (FDG uptake in 7 WFS patients aged 10.1-16.0 years (mean 12.9±2.4 and in 20 healthy children aged 3-17.9 years (mean 12.8±4.1. In all patients the diagnosis of WFS was confirmed by DNA sequencing of the WFS1 gene. Hierarchical clustering showed remarkable similarities of glucose uptake patterns among WFS patients and their differences from the control group. SUV data were subsequently standardized for age groups 13 years old to account for developmental differences. Reduced SUVs in WFS patients as compared to the control group for the bilateral brain regions such as occipital lobe (-1.24±1.20 vs. -0.13±1.05; p = 0.028 and cerebellum (-1.11±0.69 vs. -0.204±1.00; p = 0.036 were observed and the same tendency for cingulate (-1.13±1.05 vs. -0.15±1.12; p = 0.056, temporal lobe (-1.10±0.98 vs. -0.15±1.10; p = 0.057, parietal lobe (-1.06±1.20 vs. -0.08±1.08; p = 0.058, central region (-1.01±1.04 vs. -0.09±1.06; p = 0.060, basal ganglia (-1.05±0.74 vs. -0.20±1.07; p = 0.066 and mesial temporal lobe (-1.06±0.82 vs. -0.26±1.08; p = 0.087 was also noticed. After adjusting for multiple hypothesis testing, the differences in glucose uptake were non-significant. For the first time, regional differences in brain glucose metabolism among patients with WFS were shown using PET-CT imaging.

  1. 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

  2. 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.

  3. 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

  4. 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

  5. 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)

  6. 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.)

  7. 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.

  8. Pediatrics

    Science.gov (United States)

    Spackman, T. J.

    1978-01-01

    The utilization of the Lixiscope in pediatrics was investigated. The types of images that can presently be obtained are discussed along with the problems encountered. Speculative applications for the Lixiscope are also presented.

  9. Pediatrics

    NARCIS (Netherlands)

    Rasheed, Shabana; Teo, Harvey James Eu Leong; Littooij, Annemieke Simone

    2015-01-01

    Imaging of pediatric patients involves many diverse modalities, including radiography, ultrasound imaging, computed tomography, magnetic resonance imaging, and scintigraphic and angiographic studies. It is therefore important to be aware of potential pitfalls that may be related to these modalities

  10. 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.

  11. Optimizing abdominal CT dose and image quality with respect to x-ray tube voltage

    Science.gov (United States)

    Huda, Walter; Ogden, Kent M.

    2004-05-01

    , where 140 kV offers the best imaging performance. For high Z lesions of bone and iodine, imaging performance generally degrades with increasing kV for all patient sizes, with the degree of degradation largest for the smallest patients. We conclude that 80 kV is optimal with respect to radiation dose in abdominal CT for all pediatric patients. For adults, 80 kV is the x-ray voltage of choice for high Z lesions, whereas 140 kV would generally be the voltage of choice of lesions that have an atomic number similar to that of water.

  12. 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.

  13. 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.

  14. 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.

  15. 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.)

  16. Imaging in the diagnosis of pediatric urolithiasis

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  17. 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.

  18. 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

  19. Optimizing community-level surveillance data for pediatric asthma management

    Directory of Open Access Journals (Sweden)

    Wande O. Benka-Coker

    2018-06-01

    Full Text Available Community-level approaches for pediatric asthma management rely on locally collected information derived primarily from two sources: claims records and school-based surveys. We combined claims and school-based surveillance data, and examined the asthma-related risk patterns among adolescent students.Symptom data collected from school-based asthma surveys conducted in Oakland, CA were used for case identification and determination of severity levels for students (high and low. Survey data were matched to Medicaid claims data for all asthma-related health care encounters for the year prior to the survey. We then employed recursive partitioning to develop classification trees that identified patterns of demographics and healthcare utilization associated with severity.A total of 561 students had complete matched data; 86.1% were classified as high-severity, and 13.9% as low-severity asthma. The classification tree consisted of eight subsets: three indicating high severity and five indicating low severity. The risk subsets highlighted varying combinations of non-specific demographic and socioeconomic predictors of asthma prevalence, morbidity and severity. For example, the subset with the highest class-prior probability (92.1% predicted high-severity asthma and consisted of students without prescribed rescue medication, but with at least one in-clinic nebulizer treatment. The predictive accuracy of the tree-based model was approximately 66.7%, with an estimated 91.1% of high-severity cases and 42.3% of low-severity cases correctly predicted.Our analysis draws on the strengths of two complementary datasets to provide community-level information on children with asthma, and demonstrates the utility of recursive partitioning methods to explore a combination of features that convey asthma severity. Keywords: Asthma, Classification, Risk stratification, Statistical data analysis, Disease management

  20. 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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. 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.)

  3. Pulmonary CT angiography: optimization of contrast enhancement technique

    International Nuclear Information System (INIS)

    Ma Lianju; Tang Guangjian; Fu Jiazhen

    2012-01-01

    Objective: To derive and evaluate the formula of exactly calculating the contrast dosage used during pulmonary CT angiography (CTPA). Methods: Time density curves in 27 patients who underwent CTPA were collected and analyzed,the formula for calculating contrast dosage during CTPA was derived. 68 patients suspected of pulmonary embolism (PE) clinically but no PE on CTPA were divided randomly into group A, with bolus tracing technique (n=26), and group B, with small dose injection contrast test (SDCT) (n=42). The CT values of the right main pulmonary artery (RMPA), right upper pulmonary vein (RUPV), right posterior basal PA, right lower PV (RLPV) and the aorta were calculated. The total contrast dosage and the hard beam artifact in the SVC were compared between the two groups.Student's t test, Chi-square test and Mann-Whitney U test were used. Results: The ratio of the time from starting injection to enhancement peak of caudal end of SVC and the time to enhancement peak of the main pulmonary trunk was 0.65 ±0.09 (about 2/3), the formula for contrast dosage calculation was derived as (DTs/3 + STs/2) FR ml/s. The CT values of RMPA and RLPA between the two groups [(301 ±117), (329 ± 122) and (283 ±95), (277 ±98) HU respectively] were not significantly different (t=1.060, P=0.292; t=2.056, P=0.044), but the differences of CT values in the paired PA and PV between the two groups (median were 22.5, 58.0 and 170.5, 166.5 HU respectively) were significant (U=292, P=0.001 and U=325, P=0.005), contrast artifact of the SVC (grade 1-3) in group B (n=34, 7, 1 respectively) was significantly less than in group A (n=11, 10, 5 respectively, χ 2 =10.714, P=0.002), the contrast dosage injected in group A was ( 87.6 ± 7.3) ml, and in group B was (40.0 ±5.4) ml (P<0.01). Conclusion: CTPA with SDCT technique is superior to that with conventional bolus tracing technique regarding contrast dosage and contrast artifact in the SVC. (authors)

  4. Dosimetry of FDG PET/CT and other molecular imaging applications in pediatric patients

    International Nuclear Information System (INIS)

    Gelfand, Michael J.

    2009-01-01

    Effective doses for PET and SPECT imaging of molecular imaging agents depend on the radiopharmaceutical, administered activity and the weight of the patient. Effective doses for the accompanying CT scan depend on the CT protocol being used. CT protocols can be designed to produce diagnostic quality images, localization images or attenuation correction data without imaging. In each case, the co-registered molecular imaging examination (PET or SPECT) and the CT study must be acquired without patient movement. For PET/CT, attention to the respiratory phase during the CT study is also of critical importance. In addition to the molecular imaging agents 18 F-FDG and 123 I-MIBG that are frequently used in children, additional PET and SPECT imaging agents may have promise for molecular imaging in children. (orig.)

  5. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. 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.

  8. 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.

  9. Radiation dose levels in pediatric chest CT: experience in 499 children evaluated with dual-source single-energy CT

    Energy Technology Data Exchange (ETDEWEB)

    Martine, Remy-Jardin; Colas, Lucie; Jean-Baptiste, Faivre; Remy, Jacques [CHU Lille (EA 2694) University of Lille, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Santangelo, Teresa [CHU Lille (EA 2694) University of Lille, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Bambino Gesu Children' s Hospital, Department of Imaging, Rome (Italy); Duhamel, Alain [University of Lille (EA 2694), Department of Biostatistics, CHU Lille, Lille (France); Deschildre, Antoine [CHU Lille - University of Lille, Department of Pediatric Pulmonology, Lille (France)

    2017-02-15

    The availability of dual-source technology has introduced the possibility of scanning children at lower kVp with a high-pitch mode, combining high-speed data acquisition and high temporal resolution. To establish the radiation dose levels of dual-source, single-energy chest CT examinations in children. We retrospectively recorded the dose-length product (DLP) of 499 consecutive examinations obtained in children <50 kg, divided into five weight groups: group 1 (<10 kg, n = 129); group 2 (10-20 kg, n = 176); group 3 (20-30 kg, n = 99), group 4 (30-40 kg, n = 58) and group 5 (40-49 kg, n = 37). All CT examinations were performed with high temporal resolution (75 ms), a high-pitch mode and a weight-adapted selection of the milliamperage. CT examinations were obtained at 80 kVp with a milliamperage ranging between 40 mAs and 90 mAs, and a pitch of 2.0 (n = 162; 32.5%) or 3.0 (n = 337; 67.5%). The mean duration of data acquisition was 522.8 ± 192.0 ms (interquartile range 390 to 610; median 490). In the study population, the mean CT dose index volume (CTDIvol{sub 32}) was 0.83 mGy (standard deviation [SD] 0.20 mGy; interquartile range 0.72 to 0.94; median 0.78); the mean DLP{sub 32} was 21.4 mGy.cm (SD 9.1 mGy.cm; interquartile range 15 to 25; median 19.0); and the mean size-specific dose estimate (SSDE) was 1.7 mGy (SD 0.4 mGy; interquartile range 1.5 to 1.9; median 1.7). The DLP{sub 32}, CTDI{sub vol32} and SSDE were found to be statistically significant in the five weight categories (P < 0.0001). This study establishes the radiation dose levels for dual-source, single-kVp chest CT from a single center. In the five weight categories, the median values varied 15-37 mGy.cm for the DLP{sub 32}, 0.78-1.25 mGy for the CTDI{sub vol32} and 1.6-2.1 mGy for the SSDE. (orig.)

  10. Radiation dose levels in pediatric chest CT: experience in 499 children evaluated with dual-source single-energy CT

    International Nuclear Information System (INIS)

    Martine, Remy-Jardin; Colas, Lucie; Jean-Baptiste, Faivre; Remy, Jacques; Santangelo, Teresa; Duhamel, Alain; Deschildre, Antoine

    2017-01-01

    The availability of dual-source technology has introduced the possibility of scanning children at lower kVp with a high-pitch mode, combining high-speed data acquisition and high temporal resolution. To establish the radiation dose levels of dual-source, single-energy chest CT examinations in children. We retrospectively recorded the dose-length product (DLP) of 499 consecutive examinations obtained in children <50 kg, divided into five weight groups: group 1 (<10 kg, n = 129); group 2 (10-20 kg, n = 176); group 3 (20-30 kg, n = 99), group 4 (30-40 kg, n = 58) and group 5 (40-49 kg, n = 37). All CT examinations were performed with high temporal resolution (75 ms), a high-pitch mode and a weight-adapted selection of the milliamperage. CT examinations were obtained at 80 kVp with a milliamperage ranging between 40 mAs and 90 mAs, and a pitch of 2.0 (n = 162; 32.5%) or 3.0 (n = 337; 67.5%). The mean duration of data acquisition was 522.8 ± 192.0 ms (interquartile range 390 to 610; median 490). In the study population, the mean CT dose index volume (CTDIvol 32 ) was 0.83 mGy (standard deviation [SD] 0.20 mGy; interquartile range 0.72 to 0.94; median 0.78); the mean DLP 32 was 21.4 mGy.cm (SD 9.1 mGy.cm; interquartile range 15 to 25; median 19.0); and the mean size-specific dose estimate (SSDE) was 1.7 mGy (SD 0.4 mGy; interquartile range 1.5 to 1.9; median 1.7). The DLP 32 , CTDI vol32 and SSDE were found to be statistically significant in the five weight categories (P < 0.0001). This study establishes the radiation dose levels for dual-source, single-kVp chest CT from a single center. In the five weight categories, the median values varied 15-37 mGy.cm for the DLP 32 , 0.78-1.25 mGy for the CTDI vol32 and 1.6-2.1 mGy for the SSDE. (orig.)

  11. 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.)

  12. 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.)

  13. 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)

  14. 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.

  15. 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)

  16. 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.

  17. 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

  18. 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.)

  19. 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.)

  20. The use of thin-section high-resolution CT in pediatric pulmonary disease

    International Nuclear Information System (INIS)

    Hay, T.C.; Horgan, J.G.; Rumack, C.M.

    1989-01-01

    High-resolution thin-section CT of the chest was used successfully to characterize the extent of pulmonary disease. This paper reports on a study in which ten children with chronic lung disorders (including cystic fibrosis, reactive airway disease, and idiopathic disease) were evaluated to test the accuracy of the posteroanterior and lateral chest CT, with both thick (1 cm) and thin (1-3 mm) sections. Unsuspected bronchiectasis was established n two patients with reactive airway disease, and the extent of bronchiectasis in other patients was best defined on thin-section CT. Technique was crucial for an accurate study, and magnification views of each lung were useful. Thin-section CT of the chest was helpful in defining and localizing the extent of these pulmonary disorders

  1. 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.

  2. 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.)

  3. 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.

  4. 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

  5. Contrast-enhanced helical CT of the pancreas. Optimal timing of imaging for pancreatic tumor evaluation

    International Nuclear Information System (INIS)

    Koide, Kazuki; Sekiguchi, Ryuzo

    2001-01-01

    We performed three-phase helical CT in patients suspected pancreatic tumors and investigated the optimal timing of imaging for evaluation of the pancreatic mass. The pancreatic-phase was superior in detecting pancreatic tumors, including islet cell tumors that may show strong enhancement. However, portal vein-phase imaging was also superior in 16.7% of our patients. Taking into account examination for hepatic metastasis, helical CT of any pancreatic tumor should include images obtained in the pancreatic and portal vein phases. (author)

  6. Noninvasive detection of coronary abnormalities in pediatric patients with Kawassaki disease using multi-slice spiral CT

    International Nuclear Information System (INIS)

    Hou Yang; Guo Wenli; Yue Yong; Chen Liying; Guo Qiyong; Yu Xianyi; Wang Hong

    2006-01-01

    Objective: To evaluate the feasibility and value of detecting coronary artery lesions in Kawasaki disease using multi-slice computed tomography (MSCT). Methods: Thirty-four pediatric patients underwent 16-slice or 64-slice CT coronary, angiography. 18 patients were also examined with 2 dimension echocardiography (2DE). In all cases, visibility of coronary artery segment was recorded. The diameter of the LCA, RCA were measured in MSCTA and compared with 2DE. Correlation coefficient of dimension and coincidence rate of two methods were calculated. Results: Coronary artery lesions were found in 14 patients (22 branches) of the 34 cases with KD on MSCT. Six cases were dialated, 3 cases were dialated with aneurysms, 2 cases had aneurysms without dialation. Coronary artery stenosis in 1 eases, calcification in 2 cases. Three cases had multiple aneurysms with the presence of alternate stenosis that made the artery a bead-like appearance. CC of LM and RCA were 0.85, 0.91, respectively (P>0.05). Three coronary artery aneurysm in the distal RCA was missed by 2DE. MSCT could not detect slight or moderate mitral regurgitation in 2 patients and artery wall thickening in 5 patients. Conclusion: MSCT would be an effective complementary or alternative method for CDEC to evaluate coronary artery lesions non-invasively in pediatric patients with Kawasaki disease. (authors)

  7. 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

  8. 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.

  9. Optimization of CT image reconstruction algorithms for the lung tissue research consortium (LTRC)

    Science.gov (United States)

    McCollough, Cynthia; Zhang, Jie; Bruesewitz, Michael; Bartholmai, Brian

    2006-03-01

    To create a repository of clinical data, CT images and tissue samples and to more clearly understand the pathogenetic features of pulmonary fibrosis and emphysema, the National Heart, Lung, and Blood Institute (NHLBI) launched a cooperative effort known as the Lung Tissue Resource Consortium (LTRC). The CT images for the LTRC effort must contain accurate CT numbers in order to characterize tissues, and must have high-spatial resolution to show fine anatomic structures. This study was performed to optimize the CT image reconstruction algorithms to achieve these criteria. Quantitative analyses of phantom and clinical images were conducted. The ACR CT accreditation phantom containing five regions of distinct CT attenuations (CT numbers of approximately -1000 HU, -80 HU, 0 HU, 130 HU and 900 HU), and a high-contrast spatial resolution test pattern, was scanned using CT systems from two manufacturers (General Electric (GE) Healthcare and Siemens Medical Solutions). Phantom images were reconstructed using all relevant reconstruction algorithms. Mean CT numbers and image noise (standard deviation) were measured and compared for the five materials. Clinical high-resolution chest CT images acquired on a GE CT system for a patient with diffuse lung disease were reconstructed using BONE and STANDARD algorithms and evaluated by a thoracic radiologist in terms of image quality and disease extent. The clinical BONE images were processed with a 3 x 3 x 3 median filter to simulate a thicker slice reconstructed in smoother algorithms, which have traditionally been proven to provide an accurate estimation of emphysema extent in the lungs. Using a threshold technique, the volume of emphysema (defined as the percentage of lung voxels having a CT number lower than -950 HU) was computed for the STANDARD, BONE, and BONE filtered. The CT numbers measured in the ACR CT Phantom images were accurate for all reconstruction kernels for both manufacturers. As expected, visual evaluation of the

  10. Consideration of the usefulness of a size-specific dose estimate in pediatric CT examination.

    Science.gov (United States)

    Tsujiguchi, Takakiyo; Obara, Hideki; Ono, Shuichi; Saito, Yoko; Kashiwakura, Ikuo

    2018-04-05

    Computed tomography (CT) has recently been utilized in various medical settings, and technological advances have resulted in its widespread use. However, medical radiation exposure associated with CT scans accounts for the largest share of examinations using radiation; thus, it is important to understand the organ dose and effective dose in detail. The CT dose index and dose-length product are used to evaluate the organ dose. However, evaluations using these indicators fail to consider the age and body type of patients. In this study, we evaluated the effective dose based on the CT examination data of 753 patients examined at our hospital using the size-specific dose estimate (SSDE) method, which can calculate the exposure dose with consideration of the physique of a patient. The results showed a large correlation between the SSDE conversion factor and physique, with a larger exposure dose in patients with a small physique when a single scan is considered. Especially for children, the SSDE conversion factor was found to be 2 or more. In addition, the patient exposed to the largest dose in this study was a 10-year-old, who received 40.4 mSv (five series/examination). In the future, for estimating exposure using the SSDE method and in cohort studies, the diagnostic reference level of SSDE should be determined and a low-exposure imaging protocol should be developed to predict the risk of CT exposure and to maintain the quality of diagnosis with better radiation protection of patients.

  11. Optimizing Nutrition in Pediatric Heart Failure: The Crisis Is Over and Now It's Time to Feed.

    Science.gov (United States)

    Lewis, Kylie D; Conway, Jennifer; Cunningham, Chentel; Larsen, Bodil M K

    2017-06-01

    Pediatric heart failure is a complex disease occurring when cardiac output is unable to meet the metabolic demands of the body. With improved surgical interventions and medical therapies, survival rates have improved, and care has shifted from focusing on survival to optimizing quality of life and health outcomes. Based on current literature, this review addresses the nutrition needs of infants and children in heart failure and describes the pathophysiology and metabolic implications of this disease. The prevalence of wasting in pediatric heart failure has been reported to be as high as 86%, highlighting the importance of nutrition assessment through all stages of treatment to provide appropriate intake of energy, protein, and micronutrients. The etiology of malnutrition in pediatric heart failure is multifactorial and involves hypermetabolism, decreased intake, increased nutrient losses, inefficient utilization of nutrients, and malabsorption. Children in heart failure often present with tachypnea, tachycardia, fatigue, nausea, and vomiting and consequently may not be able to meet their nutrition requirements through oral intake alone. Nutrition support, including enteral nutrition and parenteral nutrition, should be considered an essential part of routine care. The involvement of multiple allied health professionals may be needed to create a feeding therapy plan to support patients and their families. With appropriate nutrition interventions, clinical outcomes and quality of life can be significantly improved.

  12. Size-specific dose estimate (SSDE) provides a simple method to calculate organ dose for pediatric CT examinations

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Bria M.; Brady, Samuel L., E-mail: samuel.brady@stjude.org; Kaufman, Robert A. [Department of Radiological Sciences, St Jude Children' s Research Hospital, Memphis, Tennessee 38105 (United States); Mirro, Amy E. [Department of Biomedical Engineering, Washington University, St Louis, Missouri 63130 (United States)

    2014-07-15

    Purpose: To investigate the correlation of size-specific dose estimate (SSDE) with absorbed organ dose, and to develop a simple methodology for estimating patient organ dose in a pediatric population (5–55 kg). Methods: Four physical anthropomorphic phantoms representing a range of pediatric body habitus were scanned with metal oxide semiconductor field effect transistor (MOSFET) dosimeters placed at 23 organ locations to determine absolute organ dose. Phantom absolute organ dose was divided by phantom SSDE to determine correlation between organ dose and SSDE. Organ dose correlation factors (CF{sub SSDE}{sup organ}) were then multiplied by patient-specific SSDE to estimate patient organ dose. The CF{sub SSDE}{sup organ} were used to retrospectively estimate individual organ doses from 352 chest and 241 abdominopelvic pediatric CT examinations, where mean patient weight was 22 kg ± 15 (range 5–55 kg), and mean patient age was 6 yrs ± 5 (range 4 months to 23 yrs). Patient organ dose estimates were compared to published pediatric Monte Carlo study results. Results: Phantom effective diameters were matched with patient population effective diameters to within 4 cm; thus, showing appropriate scalability of the phantoms across the entire pediatric population in this study. IndividualCF{sub SSDE}{sup organ} were determined for a total of 23 organs in the chest and abdominopelvic region across nine weight subcategories. For organs fully covered by the scan volume, correlation in the chest (average 1.1; range 0.7–1.4) and abdominopelvic region (average 0.9; range 0.7–1.3) was near unity. For organ/tissue that extended beyond the scan volume (i.e., skin, bone marrow, and bone surface), correlation was determined to be poor (average 0.3; range: 0.1–0.4) for both the chest and abdominopelvic regions, respectively. A means to estimate patient organ dose was demonstrated. Calculated patient organ dose, using patient SSDE and CF{sub SSDE}{sup organ}, was compared to

  13. CT features of peritoneal and mesenteric involvement in pediatric malignancies. Experience from thirteen cases

    International Nuclear Information System (INIS)

    Grenier, N.; Filiatrault, D.; Garel, L.; Dube, J.; Paille, P.; Grenier, N.

    1986-01-01

    A retrospective study of all patients presenting with abdominal malignancies since November 1982 was undertaken in order to assess the CT features of peritoneal and mesenteric involvement in childhood. Thirteen cases, including 4 cases of malignant lymphomas, 1 case of Hodgkin's disease, 5 cases of adrenal tumors and 3 cases of ovarian tumors, were selected. Providing a good technique, CT appears as the best imaging modality of the mesentery. CT is also reliable in showing peritoneal implants, even without ascites. A high quality vascular opacification is needed in order to recognize the involvement of the lesser omentum (6/13 cases in our series). Precise knowledge of the intra-abdominal extension of the primary neoplasm has a definite impact upon the surgical indications and therefore upon the prognosis [fr

  14. Accuracy and Radiation Dose Reduction of Limited-Range CT in the Evaluation of Acute Appendicitis in Pediatric Patients.

    Science.gov (United States)

    Jin, Michael; Sanchez, Thomas R; Lamba, Ramit; Fananapazir, Ghaneh; Corwin, Michael T

    2017-09-01

    The purpose of this article is to determine the accuracy and radiation dose reduction of limited-range CT prescribed from the top of L2 to the top of the pubic symphysis in children with suspected acute appendicitis. We performed a retrospective study of 210 consecutive pediatric patients from December 11, 2012, through December 11, 2014, who underwent abdominopelvic CT for suspected acute appendicitis. Two radiologists independently reviewed the theoretic limited scans from the superior L2 vertebral body to the top of the pubic symphysis, to assess for visualization of the appendix, acute appendicitis, alternative diagnoses, and incidental findings. Separately, the same parameters were assessed on the full scan by the same two reviewers. Whole-body effective doses were determined for the full- and limited-range scans and were compared using the paired t test. The appendix or entire cecum was visualized on the limited scan in all cases, and no cases of acute appendicitis were missed on the simulated limited scan compared with the full scan. Two alternative diagnoses were missed with the limited scan: one case of hydronephrosis and one of acute acalculous cholecystitis. The mean effective dose for the original scan was 5.6 mSv and that for the simulated limited scan was 3.0 mSv, resulting in a dose reduction of 46.4% (p appendicitis and reduces the dose by approximately 46%.

  15. SU-E-I-89: Assessment of CT Radiation Dose and Image Quality for An Automated Tube Potential Selection Algorithm Using Pediatric Anthropomorphic and ACR Phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Mahmood, U; Erdi, Y; Wang, W [Memorial Sloan Kettering Cancer Center, NY, NY (United States)

    2014-06-01

    Purpose: To assess the impact of General Electrics automated tube potential algorithm, kV assist (kVa) on radiation dose and image quality, with an emphasis on optimizing protocols based on noise texture. Methods: Radiation dose was assessed by inserting optically stimulated luminescence dosimeters (OSLs) throughout the body of a pediatric anthropomorphic phantom (CIRS). The baseline protocol was: 120 kVp, 80 mA, 0.7s rotation time. Image quality was assessed by calculating the contrast to noise ratio (CNR) and noise power spectrum (NPS) from the ACR CT accreditation phantom. CNRs were calculated according to the steps described in ACR CT phantom testing document. NPS was determined by taking the 3D FFT of the uniformity section of the ACR phantom. NPS and CNR were evaluated with and without kVa and for all available adaptive iterative statistical reconstruction (ASiR) settings, ranging from 0 to 100%. Each NPS was also evaluated for its peak frequency difference (PFD) with respect to the baseline protocol. Results: For the baseline protocol, CNR was found to decrease from 0.460 ± 0.182 to 0.420 ± 0.057 when kVa was activated. When compared against the baseline protocol, the PFD at ASiR of 40% yielded a decrease in noise magnitude as realized by the increase in CNR = 0.620 ± 0.040. The liver dose decreased by 30% with kVa activation. Conclusion: Application of kVa reduces the liver dose up to 30%. However, reduction in image quality for abdominal scans occurs when using the automated tube voltage selection feature at the baseline protocol. As demonstrated by the CNR and NPS analysis, the texture and magnitude of the noise in reconstructed images at ASiR 40% was found to be the same as our baseline images. We have demonstrated that 30% dose reduction is possible when using 40% ASiR with kVa in pediatric patients.

  16. SU-E-I-89: Assessment of CT Radiation Dose and Image Quality for An Automated Tube Potential Selection Algorithm Using Pediatric Anthropomorphic and ACR Phantoms

    International Nuclear Information System (INIS)

    Mahmood, U; Erdi, Y; Wang, W

    2014-01-01

    Purpose: To assess the impact of General Electrics automated tube potential algorithm, kV assist (kVa) on radiation dose and image quality, with an emphasis on optimizing protocols based on noise texture. Methods: Radiation dose was assessed by inserting optically stimulated luminescence dosimeters (OSLs) throughout the body of a pediatric anthropomorphic phantom (CIRS). The baseline protocol was: 120 kVp, 80 mA, 0.7s rotation time. Image quality was assessed by calculating the contrast to noise ratio (CNR) and noise power spectrum (NPS) from the ACR CT accreditation phantom. CNRs were calculated according to the steps described in ACR CT phantom testing document. NPS was determined by taking the 3D FFT of the uniformity section of the ACR phantom. NPS and CNR were evaluated with and without kVa and for all available adaptive iterative statistical reconstruction (ASiR) settings, ranging from 0 to 100%. Each NPS was also evaluated for its peak frequency difference (PFD) with respect to the baseline protocol. Results: For the baseline protocol, CNR was found to decrease from 0.460 ± 0.182 to 0.420 ± 0.057 when kVa was activated. When compared against the baseline protocol, the PFD at ASiR of 40% yielded a decrease in noise magnitude as realized by the increase in CNR = 0.620 ± 0.040. The liver dose decreased by 30% with kVa activation. Conclusion: Application of kVa reduces the liver dose up to 30%. However, reduction in image quality for abdominal scans occurs when using the automated tube voltage selection feature at the baseline protocol. As demonstrated by the CNR and NPS analysis, the texture and magnitude of the noise in reconstructed images at ASiR 40% was found to be the same as our baseline images. We have demonstrated that 30% dose reduction is possible when using 40% ASiR with kVa in pediatric patients

  17. 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

  18. 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

  19. 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

  20. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. 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

  3. System for verifiable CT radiation dose optimization based on image quality. part II. process control system.

    Science.gov (United States)

    Larson, David B; Malarik, Remo J; Hall, Seth M; Podberesky, Daniel J

    2013-10-01

    To evaluate the effect of an automated computed tomography (CT) radiation dose optimization and process control system on the consistency of estimated image noise and size-specific dose estimates (SSDEs) of radiation in CT examinations of the chest, abdomen, and pelvis. This quality improvement project was determined not to constitute human subject research. An automated system was developed to analyze each examination immediately after completion, and to report individual axial-image-level and study-level summary data for patient size, image noise, and SSDE. The system acquired data for 4 months beginning October 1, 2011. Protocol changes were made by using parameters recommended by the prediction application, and 3 months of additional data were acquired. Preimplementation and postimplementation mean image noise and SSDE were compared by using unpaired t tests and F tests. Common-cause variation was differentiated from special-cause variation by using a statistical process control individual chart. A total of 817 CT examinations, 490 acquired before and 327 acquired after the initial protocol changes, were included in the study. Mean patient age and water-equivalent diameter were 12.0 years and 23.0 cm, respectively. The difference between actual and target noise increased from -1.4 to 0.3 HU (P process control chart identified several special causes of variation. Implementation of an automated CT radiation dose optimization system led to verifiable simultaneous decrease in image noise variation and SSDE. The automated nature of the system provides the opportunity for consistent CT radiation dose optimization on a broad scale. © RSNA, 2013.

  4. 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.

  5. Learning with distribution of optimized features for recognizing common CT imaging signs of lung diseases

    Science.gov (United States)

    Ma, Ling; Liu, Xiabi; Fei, Baowei

    2017-01-01

    Common CT imaging signs of lung diseases (CISLs) are defined as the imaging signs that frequently appear in lung CT images from patients. CISLs play important roles in the diagnosis of lung diseases. This paper proposes a novel learning method, namely learning with distribution of optimized feature (DOF), to effectively recognize the characteristics of CISLs. We improve the classification performance by learning the optimized features under different distributions. Specifically, we adopt the minimum spanning tree algorithm to capture the relationship between features and discriminant ability of features for selecting the most important features. To overcome the problem of various distributions in one CISL, we propose a hierarchical learning method. First, we use an unsupervised learning method to cluster samples into groups based on their distribution. Second, in each group, we use a supervised learning method to train a model based on their categories of CISLs. Finally, we obtain multiple classification decisions from multiple trained models and use majority voting to achieve the final decision. The proposed approach has been implemented on a set of 511 samples captured from human lung CT images and achieves a classification accuracy of 91.96%. The proposed DOF method is effective and can provide a useful tool for computer-aided diagnosis of lung diseases on CT images.

  6. Dose responses in a normoxic polymethacrylic acid gel dosimeter using optimal CT scanning parameters

    Energy Technology Data Exchange (ETDEWEB)

    Cho, K.H. [Department of Radiation Oncology, College of Medicine, Soonchunhyang University, Bucheon 420-767 (Korea, Republic of); Department of Medical Physics, Kyonggi University, Suwon 443-760 (Korea, Republic of); Cho, S.J. [Department of Radiation Oncology, College of Medicine, Eulji University, Seongnam 461-713 (Korea, Republic of); Lee, S. [Department of Radiation Oncology, College of Medicine, Korea University, Seoul 130-701 (Korea, Republic of); Lee, S.H. [Cheil General Hospital and Women' s Healthcare Center, Kwandong University College of Medicine, Seoul 100-380 (Korea, Republic of); Min, C.K.; Kim, Y.H.; Moon, S.K.; Kim, E.S.; Chang, A.R. [Department of Radiation Oncology, College of Medicine, Soonchunhyang University, Bucheon 420-767 (Korea, Republic of); Kwon, S.I., E-mail: sikwon@kyonggi.ac.kr [Department of Medical Physics, Kyonggi University, Suwon 443-760 (Korea, Republic of)

    2012-05-21

    The dosimetric characteristics of normoxic polymethacrylic acid gels are investigated using optimal CT scanning parameters and the possibility of their clinical application is also considered. The effects of CT scanning parameters (tube voltage, tube current, scan time, slick thickness, field of view, and reconstruction algorithm) are experimentally investigated to determine the optimal parameters for minimizing the amount of noise in images obtained using normoxic polymethacrylic acid gel. In addition, the dose sensitivity, dose response, accuracy, and reproducibility of the normoxic polymethacrylic acid gel are evaluated. CT images are obtained using a head phantom that is fabricated for clinical applications. In addition, IMRT treatment planning is performed using a Tomotherapy radiation treatment planning system. A program for analyzing the results is produced using Visual C. A comparison between the treatment planning and the CT images of irradiated gels is performed. The dose sensitivity is found to be 2.41{+-}0.04 HGy{sup -1}. The accuracies of dose evaluation at doses of 2 Gy and 4 Gy are 3.0% and 2.6%, respectively, and their reproducibilities are 2.0% and 2.1%, respectively. In the comparison of gel and Tomotherpay planning, the pass rate of the {gamma}-index, based on the reference values of a dose error of 3% and a DTA of 3 mm, is 93.7%.

  7. Dose responses in a normoxic polymethacrylic acid gel dosimeter using optimal CT scanning parameters

    Science.gov (United States)

    Cho, K. H.; Cho, S. J.; Lee, S.; Lee, S. H.; Min, C. K.; Kim, Y. H.; Moon, S. K.; Kim, E. S.; Chang, A. R.; Kwon, S. I.

    2012-05-01

    The dosimetric characteristics of normoxic polymethacrylic acid gels are investigated using optimal CT scanning parameters and the possibility of their clinical application is also considered. The effects of CT scanning parameters (tube voltage, tube current, scan time, slick thickness, field of view, and reconstruction algorithm) are experimentally investigated to determine the optimal parameters for minimizing the amount of noise in images obtained using normoxic polymethacrylic acid gel. In addition, the dose sensitivity, dose response, accuracy, and reproducibility of the normoxic polymethacrylic acid gel are evaluated. CT images are obtained using a head phantom that is fabricated for clinical applications. In addition, IMRT treatment planning is performed using a Tomotherapy radiation treatment planning system. A program for analyzing the results is produced using Visual C. A comparison between the treatment planning and the CT images of irradiated gels is performed. The dose sensitivity is found to be 2.41±0.04 HGy-1. The accuracies of dose evaluation at doses of 2 Gy and 4 Gy are 3.0% and 2.6%, respectively, and their reproducibilities are 2.0% and 2.1%, respectively. In the comparison of gel and Tomotherpay planning, the pass rate of the γ-index, based on the reference values of a dose error of 3% and a DTA of 3 mm, is 93.7%.

  8. First experiences of application of computer tomography (CT) in pediatric neurology

    International Nuclear Information System (INIS)

    Nagy, I.; Deak, Gy.; Paraicz, E.

    1980-01-01

    79 children were examined by the first Hungarian CT equipment (Medicor-CGR Densitome connected to a PDP 11/55 computer). The advantages of the method in the diagnosis of malformations, perinatal injuries, hydrocephalus, skull injuries and cerebral tumours are demonstrated. The problems arising from the application of instruments requiring long examination time are discussed. (L.E.)

  9. First experiences of application of computer tomography (CT) in pediatric neurology

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, I; Deak, Gy; Paraicz, E [Orszagos Idegsebeszeti Tudomanyos Intezet, Budapest (Hungary)

    1980-01-01

    79 children were examined by the first Hungarian CT equipment (Medicor-CGR Densitome connected to a PDP 11/55 computer). The advantages of the method in the diagnosis of malformations, perinatal injuries, hydrocephalus, skull injuries and cerebral tumours are demonstrated. The problems arising from the application of instruments requiring long examination time are discussed.

  10. Unusual finding in pediatric Churg-Strauss: renal lesions on CT

    International Nuclear Information System (INIS)

    Oldan, Jorge; McCauley, Roy; Pilichowska, Monica; Milner, Lawrence; Lopez-Benitez, Jorge M.

    2011-01-01

    After a 19-year-old female experienced several weeks of unrelieved fevers, an abdominal CT revealed multiple low-attenuation renal lesions. As the differential included lymphoma, infections and infarcts, a core biopsy of the kidney was performed, which revealed changes consistent with Churg-Strauss syndrome. (orig.)

  11. Unusual finding in pediatric Churg-Strauss: renal lesions on CT

    Energy Technology Data Exchange (ETDEWEB)

    Oldan, Jorge; McCauley, Roy [Tufts Medical Center, Department of Radiology, Boston, MA (United States); Pilichowska, Monica [Tufts Medical Center, Department of Pathology, Boston, MA (United States); Milner, Lawrence [Tufts Medical Center, Department of Nephrology, Boston, MA (United States); Lopez-Benitez, Jorge M [Tufts Medical Center, Department of Rheumatology, Boston, MA (United States)

    2011-08-15

    After a 19-year-old female experienced several weeks of unrelieved fevers, an abdominal CT revealed multiple low-attenuation renal lesions. As the differential included lymphoma, infections and infarcts, a core biopsy of the kidney was performed, which revealed changes consistent with Churg-Strauss syndrome. (orig.)

  12. A trial of CT technique for the cleft lip and palate in the pediatrics

    International Nuclear Information System (INIS)

    Arai, Katsuyuki; Yabe, Yoshinori.

    1980-01-01

    To visualize rupture of the alveolar process of the maxilla caused by cleft lip and palate, deformity of external form of the nose following rupture of the alveolar process, and rupture of the palate most clearly on CT images, the position and the angle of inclination of slice phases were discussed by using CT images of the skull and cleft lip and palate. The clearest CT images of rupture of alveolar process of the maxilla in infants with cleft lip were obtained when images of frontal section were taken with an mean angle of inclination of 10 0 between slice phase and base line and 4 cm distance from base line on OM line. Clear images of cleft condition in infants with cleft palate were obtained when images of horizontal section at earhole on base line were taken with an inclination of about -10 0 . Conditions to visualize the nasal septum and alar cartilage which influenced seriously the external form of nose was also referred to. (Tsunoda, M.)

  13. CT urograms in pediatric patients with ureteral calculi: do adult criteria work?

    International Nuclear Information System (INIS)

    Smergel, E.; Greenberg, S.B.; Crisci, K.L.; Salwen, J.K.

    2001-01-01

    Background: Secondary signs of urinary obstruction associated with ureteral calculi are useful adjuncts to diagnosis in adults with renal colic evaluated by unenhanced helical CT. Objective: Our purpose was to evaluate the frequency of secondary signs of obstruction in children with renal colic undergoing unenhanced helical CT. Materials and methods: Ureteral calculi were identified in 20 of 61 children with acute flank pain examined by unenhanced helical CT. Each imaging study was evaluated for the presence of secondary signs of urinary obstruction. The frequencies of individual signs were compared with each other by means of the McNemar test. Results: Six children had no secondary sign identified. In the remaining 14 children, proximal ureteral dilatation was seen in 10, renal enlargement in 10, hydronephrosis in 9, tissue rim sign in 6, decreased kidney attenuation in 5, and perinephric stranding in 1. Comparison of the frequencies strongly suggested that perinephric stranding occurs less frequently than proximal ureteral dilatation (P = 0.004), hydronephrosis (P = 0.008), or renal enlargement (P = 0.012). Conclusion: Perinephric stranding, a common secondary sign in adults with ureteral calculi, occurs less frequently in children than other reported secondary signs. (orig.)

  14. CT urograms in pediatric patients with ureteral calculi: do adult criteria work?

    Energy Technology Data Exchange (ETDEWEB)

    Smergel, E.; Greenberg, S.B.; Crisci, K.L.; Salwen, J.K. [Dept. of Radiology, St. Christopher' s Hospital for Children, Philadelphia, PA (United States)

    2001-10-01

    Background: Secondary signs of urinary obstruction associated with ureteral calculi are useful adjuncts to diagnosis in adults with renal colic evaluated by unenhanced helical CT. Objective: Our purpose was to evaluate the frequency of secondary signs of obstruction in children with renal colic undergoing unenhanced helical CT. Materials and methods: Ureteral calculi were identified in 20 of 61 children with acute flank pain examined by unenhanced helical CT. Each imaging study was evaluated for the presence of secondary signs of urinary obstruction. The frequencies of individual signs were compared with each other by means of the McNemar test. Results: Six children had no secondary sign identified. In the remaining 14 children, proximal ureteral dilatation was seen in 10, renal enlargement in 10, hydronephrosis in 9, tissue rim sign in 6, decreased kidney attenuation in 5, and perinephric stranding in 1. Comparison of the frequencies strongly suggested that perinephric stranding occurs less frequently than proximal ureteral dilatation (P = 0.004), hydronephrosis (P = 0.008), or renal enlargement (P = 0.012). Conclusion: Perinephric stranding, a common secondary sign in adults with ureteral calculi, occurs less frequently in children than other reported secondary signs. (orig.)

  15. 16 multi-slice CT three-dimensional and multiplanar reconstruction for evaluation of pediatric congenital scoliosis

    International Nuclear Information System (INIS)

    Peng Yun; Zhang Ningning; Zhang Xuejun; Sun Guoqiang; Zeng Jinjin

    2006-01-01

    Objective: Our study is to use of 16 MSCT three-dimensional images and multiplanar reconstruction images in the preoperative investigation of patients with congenital scoliosis, to study its technical advantage and work out surgical plan. Methods: Twenty-seven pediatric patients with congenital scoliosis processing between April to October 2004 were reviewed, including 13 boys and 14 girls. X-ray plain film and sixteen multi-slice CT examination on curved/standard multiplanar reconstruction and three- dimensional computed tomographic imaging may offer, many potential advantages for defining congenital spine anomalies liable to cause progression of scoliosis, including visualization of the deformity in any plane, from any angle, with the overlying structures subtracted. Results: Ten patients had segmentation defects, 6 patients underwent formation defects, 11 patients had complex, unclassifiable anomalies. The patients of rib deformity were found in 15 patients, the most prominent part of the rib cage deformity was at the same level as the most rotated vertebra in 7 patients; 8 patients had vertebral anomalies accompanied with diastematomyelie, including 6 patients with uncompleted or completed bony spur. In 19 of 27 cases, the muhiplanar reconstruction and three-dimensional images allowed identification of unrecognized malformations and completely evaluated the degree of scoliosis, during conventional X-ray images and axial CT images, including volume 3D imaging evaluated approximately classification and modality of complex anomalies in 11 cases, which were unclassifiable malformation in 7 cases and unsegmented bar with contralateral hemivertebrae; 4 children had segmentation defects revealed unilateral unsegmented bar (3 cases) and bilateral block vertebra (1 case) in volume 3D reconstruction images; 2 children were found occultation hemivertebrae which were not been discovered during conventional X-ray images and axial CT images; and 2 children were revaluated

  16. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  18. Reducing 4D CT artifacts using optimized sorting based on anatomic similarity.

    Science.gov (United States)

    Johnston, Eric; Diehn, Maximilian; Murphy, James D; Loo, Billy W; Maxim, Peter G

    2011-05-01

    Four-dimensional (4D) computed tomography (CT) has been widely used as a tool to characterize respiratory motion in radiotherapy. The two most commonly used 4D CT algorithms sort images by the associated respiratory phase or displacement into a predefined number of bins, and are prone to image artifacts at transitions between bed positions. The purpose of this work is to demonstrate a method of reducing motion artifacts in 4D CT by incorporating anatomic similarity into phase or displacement based sorting protocols. Ten patient datasets were retrospectively sorted using both the displacement and phase based sorting algorithms. Conventional sorting methods allow selection of only the nearest-neighbor image in time or displacement within each bin. In our method, for each bed position either the displacement or the phase defines the center of a bin range about which several candidate images are selected. The two dimensional correlation coefficients between slices bordering the interface between adjacent couch positions are then calculated for all candidate pairings. Two slices have a high correlation if they are anatomically similar. Candidates from each bin are then selected to maximize the slice correlation over the entire data set using the Dijkstra's shortest path algorithm. To assess the reduction of artifacts, two thoracic radiation oncologists independently compared the resorted 4D datasets pairwise with conventionally sorted datasets, blinded to the sorting method, to choose which had the least motion artifacts. Agreement between reviewers was evaluated using the weighted kappa score. Anatomically based image selection resulted in 4D CT datasets with significantly reduced motion artifacts with both displacement (P = 0.0063) and phase sorting (P = 0.00022). There was good agreement between the two reviewers, with complete agreement 34 times and complete disagreement 6 times. Optimized sorting using anatomic similarity significantly reduces 4D CT motion

  19. Quality and dose optimized CT trauma protocol. Recommendation from a university level-I trauma center

    Energy Technology Data Exchange (ETDEWEB)

    Kahn, Johannes; Boening, Georg; Rotzinger, Roman; Freyhardt, Patrick; Streitparth, Florian [Charite School of Medicine and Univ. Hospital Berlin (Germany). Dept. of Radiology; Kaul, David [Charite School of Medicine and Univ. Hospital Berlin (Germany). Dept. of Radiation Oncology; Schwabe, Philipp [Charite School of Medicine and Univ. Hospital Berlin (Germany). Dept. of Trauma Surgery; Maurer, Martin H. [Inselspital Bern (Switzerland). Dept. of Diagnostic, Interventional and Pediatric Radiology; Renz, Diane Miriam [Univ. Hospital Jena (Germany). Inst. of Diagnostic and Interventional Radiology

    2017-09-15

    As a supra-regional level-I trauma center, we evaluated computed tomography (CT) acquisitions of polytraumatized patients for quality and dose optimization purposes. Adapted statistical iterative reconstruction [(AS)IR] levels, tube voltage reduction as well as a split-bolus contrast agent (CA) protocol were applied. Materials and Methods 61 patients were split into 3 different groups that differed with respect to tube voltage (120 - 140 kVp) and level of applied ASIR reconstruction (ASIR 20 - 50%). The CT protocol included a native acquisition of the head followed by a single contrast-enhanced acquisition of the whole body (64-MSCT). CA (350 mg/ml iodine) was administered as a split bolus injection of 100 ml (2 ml/s), 20 ml NaCl (1 ml/s), 60 ml (4 ml/s), 40 ml NaCl (4 ml/s) with a scan delay of 85s to detect injuries of both the arterial system and parenchymal organs in a single acquisition. Both the quantitative (SNR/CNR) and qualitative (5-point Likert scale) image quality was evaluated in parenchymal organs that are often injured in trauma patients. Radiation exposure was assessed. The use of IR combined with a reduction of tube voltage resulted in good qualitative and quantitative image quality and a significant reduction in radiation exposure of more than 40% (DLP 1087 vs. 647 mGy x cm). Image quality could be improved due to a dedicated protocol that included different levels of IR adapted to different slice thicknesses, kernels and the examined area for the evaluation of head, lung, body and bone injury patterns. In synopsis of our results, we recommend the implementation of a polytrauma protocol with a tube voltage of 120 kVp and the following IR levels: cCT 5mm: ASIR 20; cCT 0.625 mm: ASIR 40; lung 2.5 mm: ASIR 30, body 5 mm: ASIR 40; body 1.25 mm: ASIR 50; body 0.625 mm: ASIR 0. A dedicated adaptation of the CT trauma protocol (level of reduction of tube voltage and of IR) according to the examined body region (head, lung, body, bone) combined with a

  20. Quality and dose optimized CT trauma protocol. Recommendation from a university level-I trauma center

    International Nuclear Information System (INIS)

    Kahn, Johannes; Boening, Georg; Rotzinger, Roman; Freyhardt, Patrick; Streitparth, Florian; Kaul, David; Schwabe, Philipp; Maurer, Martin H.; Renz, Diane Miriam

    2017-01-01

    As a supra-regional level-I trauma center, we evaluated computed tomography (CT) acquisitions of polytraumatized patients for quality and dose optimization purposes. Adapted statistical iterative reconstruction [(AS)IR] levels, tube voltage reduction as well as a split-bolus contrast agent (CA) protocol were applied. Materials and Methods 61 patients were split into 3 different groups that differed with respect to tube voltage (120 - 140 kVp) and level of applied ASIR reconstruction (ASIR 20 - 50%). The CT protocol included a native acquisition of the head followed by a single contrast-enhanced acquisition of the whole body (64-MSCT). CA (350 mg/ml iodine) was administered as a split bolus injection of 100 ml (2 ml/s), 20 ml NaCl (1 ml/s), 60 ml (4 ml/s), 40 ml NaCl (4 ml/s) with a scan delay of 85s to detect injuries of both the arterial system and parenchymal organs in a single acquisition. Both the quantitative (SNR/CNR) and qualitative (5-point Likert scale) image quality was evaluated in parenchymal organs that are often injured in trauma patients. Radiation exposure was assessed. The use of IR combined with a reduction of tube voltage resulted in good qualitative and quantitative image quality and a significant reduction in radiation exposure of more than 40% (DLP 1087 vs. 647 mGy x cm). Image quality could be improved due to a dedicated protocol that included different levels of IR adapted to different slice thicknesses, kernels and the examined area for the evaluation of head, lung, body and bone injury patterns. In synopsis of our results, we recommend the implementation of a polytrauma protocol with a tube voltage of 120 kVp and the following IR levels: cCT 5mm: ASIR 20; cCT 0.625 mm: ASIR 40; lung 2.5 mm: ASIR 30, body 5 mm: ASIR 40; body 1.25 mm: ASIR 50; body 0.625 mm: ASIR 0. A dedicated adaptation of the CT trauma protocol (level of reduction of tube voltage and of IR) according to the examined body region (head, lung, body, bone) combined with a

  1. 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.

  2. Selecting optimal monochromatic level with spectral CT imaging for improving imaging quality in hepatic venography

    International Nuclear Information System (INIS)

    Sun Jun; Luo Xianfu; Wang Shou'an; Wang Jun; Sun Jiquan; Wang Zhijun; Wu Jingtao

    2013-01-01

    Objective: To investigate the effect of spectral CT monochromatic images for improving imaging quality in hepatic venography. Methods: Thirty patients underwent spectral CT examination on a GE Discovery CT 750 HD scanner. During portal phase, 1.25 mm slice thickness polychromatic images and optimal monochromatic images were obtained, and volume rendering and maximum intensity projection were created to show the hepatic veins respectively. The overall imaging quality was evaluated on a five-point scale by two radiologists. Inter-observer agreement in subjective image quality grading was assessed by Kappa statistics. Paired-sample t test were used to compare hepatic vein attenuation, hepatic parenchyma attenuation, CT value difference between the hepatic vein and the liver parenchyma, image noise, vein-to-liver contrast-to-noise ratio (CNR), the image quality score of hepatic venography between the two image data sets. Results: The monochromatic images at 50 keV were found to demonstrate the best CNR for hepatic vein.The hepatic vein attenuation [(329 ± 47) HU], hepatic parenchyma attenuation [(178 ± 33) HU], CT value difference between the hepatic vein and the liver parenchyma [(151 ± 33) HU], image noise (17.33 ± 4.18), CNR (9.13 ± 2.65), the image quality score (4.2 ± 0.6) of optimal monochromatic images were significantly higher than those of polychromatic images [(149 ± 18) HU], [(107 ± 14) HU], [(43 ±11) HU], 12.55 ± 3.02, 3.53 ± 1.03, 3.1 ± 0.8 (t values were 24.79, 13.95, 18.85, 9.07, 13.25 and 12.04, respectively, P < 0.01). In the comparison of image quality, Kappa value was 0.81 with optimal monochromatic images and 0.69 with polychromatic images. Conclusion: Monochromatic images of spectral CT could improve CNR for displaying hepatic vein and improve the image quality compared to the conventional polychromatic images. (authors)

  3. 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

  4. Metal artifact reduction in x-ray computed tomography (CT) by constrained optimization

    International Nuclear Information System (INIS)

    Zhang Xiaomeng; Wang Jing; Xing Lei

    2011-01-01

    Purpose: The streak artifacts caused by metal implants have long been recognized as a problem that limits various applications of CT imaging. In this work, the authors propose an iterative metal artifact reduction algorithm based on constrained optimization. Methods: After the shape and location of metal objects in the image domain is determined automatically by the binary metal identification algorithm and the segmentation of ''metal shadows'' in projection domain is done, constrained optimization is used for image reconstruction. It minimizes a predefined function that reflects a priori knowledge of the image, subject to the constraint that the estimated projection data are within a specified tolerance of the available metal-shadow-excluded projection data, with image non-negativity enforced. The minimization problem is solved through the alternation of projection-onto-convex-sets and the steepest gradient descent of the objective function. The constrained optimization algorithm is evaluated with a penalized smoothness objective. Results: The study shows that the proposed method is capable of significantly reducing metal artifacts, suppressing noise, and improving soft-tissue visibility. It outperforms the FBP-type methods and ART and EM methods and yields artifacts-free images. Conclusions: Constrained optimization is an effective way to deal with CT reconstruction with embedded metal objects. Although the method is presented in the context of metal artifacts, it is applicable to general ''missing data'' image reconstruction problems.

  5. Clinical and CT features of benign pneumatosis intestinalis in pediatric hematopoietic stem cell transplant and oncology patients

    International Nuclear Information System (INIS)

    McCarville, M.B.; Goodin, Geoffrey S.; Whittle, Sarah B.; Li, Chin-Shang; Smeltzer, Matthew P.; Hale, Gregory A.; Kaufman, Robert A.

    2008-01-01

    Pneumatosis intestinalis in children is associated with a wide variety of underlying conditions and often has a benign course. The CT features of this condition have not been systematically investigated. Defining benign pneumatosis intestinalis as pneumatosis intestinalis that resolved with medical management alone, we sought to: (1) determine whether the incidence of benign pneumatosis intestinalis had increased at our pediatric cancer hospital; (2) characterize CT features of benign pneumatosis intestinalis; and (3) determine the relationship between imaging features and clinical course of benign pneumatosis intestinalis in this cohort. Radiology reports from November 1994 to December 2006 were searched for ''pneumatosis intestinalis,'' ''free intraperitoneal air,'' and ''portal venous air or gas.'' Corresponding imaging was reviewed by two radiologists who confirmed pneumatosis intestinalis and recorded the presence of extraluminal free air, degree of intramural gaseous distension, number of involved bowel segments, and time to pneumatosis resolution. The search revealed 12 boys and 4 girls with pneumatosis intestinalis; 11 were hematopoietic stem cell transplant recipients. The annual incidences of benign pneumatosis have not changed at our institution. Increases in intramural distension marginally correlated with the number of bowel segments involved (P=0.08). Three patients had free air and longer times to resolution of pneumatosis (P=0.03). Male children may be at increased risk of benign pneumatosis intestinalis. The incidence of benign pneumatosis at our institution is proportional to the number of hematopoietic stem cell transplants. The degree of intramural distension may correlate with the number of bowel segments involved. Patients with free air have a longer time to resolution of benign pneumatosis. (orig.)

  6. 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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Model-based iterative reconstruction in pediatric chest CT: assessment of image quality in a prospective study of children with cystic fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Mieville, Frederic A.; Bochud, Francois O.; Verdun, Francis R. [Lausanne University Hospital, Institute of Radiation Physics, Lausanne (Switzerland); Berteloot, Laureline; Brunelle, Francis [Necker Children' s Hospital of Paris and University of Paris Descartes, Department of Pediatric Radiology, Paris (France); Grandjean, Albane; Ayestaran, Paul [General Electric Medical Systems Europe, Paris (France); Gudinchet, Francois; Schmidt, Sabine [Lausanne University Hospital, Department of Radiology, Lausanne (Switzerland)

    2013-03-15

    The potential effects of ionizing radiation are of particular concern in children. The model-based iterative reconstruction VEO trademark is a technique commercialized to improve image quality and reduce noise compared with the filtered back-projection (FBP) method. To evaluate the potential of VEO trademark on diagnostic image quality and dose reduction in pediatric chest CT examinations. Twenty children (mean 11.4 years) with cystic fibrosis underwent either a standard CT or a moderately reduced-dose CT plus a minimum-dose CT performed at 100 kVp. Reduced-dose CT examinations consisted of two consecutive acquisitions: one moderately reduced-dose CT with increased noise index (NI = 70) and one minimum-dose CT at CTDI{sub vol} 0.14 mGy. Standard CTs were reconstructed using the FBP method while low-dose CTs were reconstructed using FBP and VEO. Two senior radiologists evaluated diagnostic image quality independently by scoring anatomical structures using a four-point scale (1 = excellent, 2 = clear, 3 = diminished, 4 = non-diagnostic). Standard deviation (SD) and signal-to-noise ratio (SNR) were also computed. At moderately reduced doses, VEO images had significantly lower SD (P < 0.001) and higher SNR (P < 0.05) in comparison to filtered back-projection images. Further improvements were obtained at minimum-dose CT. The best diagnostic image quality was obtained with VEO at minimum-dose CT for the small structures (subpleural vessels and lung fissures) (P < 0.001). The potential for dose reduction was dependent on the diagnostic task because of the modification of the image texture produced by this reconstruction. At minimum-dose CT, VEO enables important dose reduction depending on the clinical indication and makes visible certain small structures that were not perceptible with filtered back-projection. (orig.)

  8. 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.)

  9. 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

  10. The Lobe Fissure Tracking by the Modified Ant Colony Optimization Framework in CT Images

    Directory of Open Access Journals (Sweden)

    Chii-Jen Chen

    2014-11-01

    Full Text Available Chest computed tomography (CT is the most commonly used technique for the inspection of lung lesions. However, the lobe fissures in lung CT is still difficult to observe owing to its imaging structure. Therefore, in this paper, we aimed to develop an efficient tracking framework to extract the lobe fissures by the proposed modified ant colony optimization (ACO algorithm. We used the method of increasing the consistency of pheromone on lobe fissure to improve the accuracy of path tracking. In order to validate the proposed system, we had tested our method in a database from 15 lung patients. In the experiment, the quantitative assessment shows that the proposed ACO method achieved the average F-measures of 80.9% and 82.84% in left and right lungs, respectively. The experiments indicate our method results more satisfied performance, and can help investigators detect lung lesion for further examination.

  11. Determination of optimal parameters for three-dimensional reconstruction images of central airways using helical CT

    International Nuclear Information System (INIS)

    Hirose, Takahumi; Akata, Soichi; Matsuno, Naoto; Nagao, Takeshi; Abe, Kimihiko

    2002-01-01

    Three-dimensional (3D) image reconstruction of central airways using helical CT requires several user-defined parameters that exceed the requirements of conventional CT. The purpose of this study was to evaluate the optimal parameters for 3D images of central airways using helical CT. In our experimental study using a piglet immediately after sacrifice, 3D images of the central airway were evaluated with changes of 3D imaging parameters, such as detector collimation (1, 2, 3 and 6 mm), table speed (1, 2, 3 and 5 mm/sec), tube electric current (50, 100, 150, 200 and 250 mA), reconstruction interval (0.3, 0.5, 1, 2 and 3 mm), algorithm (mediastinum and lung) and interpolation method (180 deg and 360 deg). To minimize detector collimation, table speed, and reconstruction interval could provide the best 3D images of the central airway. Stair-step artifacts could also be reduced with a slow table speed. However, decreasing the collimation and table speed decreases not only the effective section thickness but also the scan coverage that can be achieved with a helical CT. For routine diagnosis, we conclude that optimal parameters for 3D images of the central airway are to minimize the table speed necessary to cover the volume of interest and to set detector collimation to 1/2 of the table speed. The reconstruction intervals should also be selected at up to 1/2 of the detector collimation, but with trade-offs of increased image processing time, data storage requirements, and physician time for image review. Regarding to tube electric current, 200 mA or more was necessary. Pixel noise increased with the algorithm for the lung. The 180 deg interpolation is better than 360 deg interpolation due to thin effective section thickness. (author)

  12. CLINICAL AND PHARMACOLOGICAL APPROACHES TO OPTIMIZE THE DOSING REGIMEN OF ANTIBACTERIAL DRUGS IN PEDIATRICS

    Directory of Open Access Journals (Sweden)

    Natal’ya B. Lazareva

    2018-01-01

    Full Text Available The rational use of antibacterial drugs in children implies an adequate choice of the necessary medication, its dosing regimen, and the duration of treatment in order to achieve maximum efficacy and minimize toxic effects. The knowledge of pharmacokinetic and pharmacodynamic profiles of the antibacterial drug plays a crucial role for optimizing the dosing regimen. The strategy of individual choice of the dosing regimen, taking into account the principles of pharmacokinetics and pharmacodynamics, can be especially effective in patients with the expectedly changed parameters of pharmacokinetics and in infections caused by bacteria strains with low sensitivity to antibiotics. The review presents a contemporary view of pharmacokinetic and pharmacodynamic profiles of antibacterial drugs most commonly used in pediatrics and their relationship to the clinical efficacy of the administered therapy.

  13. Optimization of folic acid, vitamin B-12, and vitamin B-6 supplements in pediatric patients with sickle cell disease

    NARCIS (Netherlands)

    van der Dijs, Fey P L; Fokkema, M Rebecca; Dijck-Brouwer, D A Janneke; Niessink, Bram; van der Wal, Thaliet I C; Schnog, John-John B; Duits, Ashley J; Muskiet, Fred D; Muskiet, Frits A J

    Using homocysteine as a functional marker, we determined optimal folic acid, vitamin B-12, and vitamin B-6 dosages in 21 pediatric sickle cell disease (SCD) patients (11 HbSS, 10 HbSC; 7-16 years). Daily supplements of folic acid (400, 700, or 1,000 mug), vitamin B-12 (1, 3, or 5 U.S. 1989 RDA), and

  14. 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.

  15. 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

    Energy Technology Data Exchange (ETDEWEB)

    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

  16. 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 ( ...

  17. Quality and Dose Optimized CT Trauma Protocol - Recommendation from a University Level-I Trauma Center.

    Science.gov (United States)

    Kahn, Johannes; Kaul, David; Böning, Georg; Rotzinger, Roman; Freyhardt, Patrick; Schwabe, Philipp; Maurer, Martin H; Renz, Diane Miriam; Streitparth, Florian

    2017-09-01

    Purpose  As a supra-regional level-I trauma center, we evaluated computed tomography (CT) acquisitions of polytraumatized patients for quality and dose optimization purposes. Adapted statistical iterative reconstruction [(AS)IR] levels, tube voltage reduction as well as a split-bolus contrast agent (CA) protocol were applied. Materials and Methods  61 patients were split into 3 different groups that differed with respect to tube voltage (120 - 140 kVp) and level of applied ASIR reconstruction (ASIR 20 - 50 %). The CT protocol included a native acquisition of the head followed by a single contrast-enhanced acquisition of the whole body (64-MSCT). CA (350 mg/ml iodine) was administered as a split bolus injection of 100 ml (2 ml/s), 20 ml NaCl (1 ml/s), 60 ml (4 ml/s), 40 ml NaCl (4 ml/s) with a scan delay of 85 s to detect injuries of both the arterial system and parenchymal organs in a single acquisition. Both the quantitative (SNR/CNR) and qualitative (5-point Likert scale) image quality was evaluated in parenchymal organs that are often injured in trauma patients. Radiation exposure was assessed. Results  The use of IR combined with a reduction of tube voltage resulted in good qualitative and quantitative image quality and a significant reduction in radiation exposure of more than 40 % (DLP 1087 vs. 647 mGyxcm). Image quality could be improved due to a dedicated protocol that included different levels of IR adapted to different slice thicknesses, kernels and the examined area for the evaluation of head, lung, body and bone injury patterns. In synopsis of our results, we recommend the implementation of a polytrauma protocol with a tube voltage of 120 kVp and the following IR levels: cCT 5mm: ASIR 20; cCT 0.625 mm: ASIR 40; lung 2.5 mm: ASIR 30, body 5 mm: ASIR 40; body 1.25 mm: ASIR 50; body 0.625 mm: ASIR 0. Conclusion  A dedicated adaptation of the CT trauma protocol (level of reduction of tube voltage and of IR

  18. Dual-phase helical CT using bolus triggering technique: optimization of transition time

    International Nuclear Information System (INIS)

    Choi, Young Ho; Kim, Tae Kyoung; Park, Byung Kwan; Koh, Young Hwan; Han, Joon Koo; Choi, Byung Ihn

    1999-01-01

    To optimize the transition time between the triggering point in monitoring scanning and the initiation of diagnostic hepatic arterial phase (HAP) scanning in hepatic spiral CT, using a bolus triggering technique. One hundred consecutive patients with focal hepatic lesion were included in this study. Patients were randomized into two groups. Transition times of 7 and 11 seconds were used in group 1 and 2, respectively. In all patients, bolus triggered HAP spiral CT was obtained using a semi-automatic bolus tracking program after the injection of 120mL of non-ionic contrast media at a rate of 3mL/sec. When aortic enhancement reached 90 HU, diagnostic HAP scanning began after a given transition time. From images of group 1 and group 2, the degree of parenchymal enhancement of the liver and tumor-to-liver attenuation difference were measured. Also, for qualitative analysis, conspicuity of the hepatic artery and hypervascular tumor was scored and analyzed. Hepatic parenchymal enhancement on HAP was 12.07 + /-6.44 HU in group 1 and 16.03 + /-5.80 HU in group 2 (p .05). In the evaluation of conspicuity of hepatic artery, there was no statistically significant difference between the two groups (p > .05). The conspicuity of hypervascular tumors in group 2 was higher than in group 1 (p < .05). HAP spiral CT using a bolus triggering technique with a transition time of 11 seconds provides better HAP images than when the transition time is 7 seconds

  19. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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. ...

  20. Computed Tomography (CT) -- Head

    Medline Plus

    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. ...

  1. Abdominal and Pelvic CT

    Medline Plus

    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. ...

  2. Automatic exposure control in pediatric and adult multidetector CT examinations: A phantom study on dose reduction and image quality

    Energy Technology Data Exchange (ETDEWEB)

    Papadakis, Antonios E.; Perisinakis, Kostas; Damilakis, John [Department of Medical Physics, Faculty of Medicine, University of Crete, P.O. Box 1352, Iraklion 71110, Crete (Greece)

    2008-10-15

    The aim of this study was to assess the potential of a modern x,y,z modulation-based automatic exposure control system (AEC) for dose reduction in pediatric and adult multidetector CT (MDCT) imaging and evaluate the quality of the images obtained. Five physical anthropomorphic phantoms that simulate the average individual as neonate, 1-, 5-, 10-year old child, and adult were scanned with a MDCT scanner, equipped with a modern AEC system. Dose reduction (%DR) was calculated as the percentage difference of the mean modulated and the preset tube current-time product that is prescribed for standard head and body scan protocols. The effect of the tube potential and the orientation of the topogram acquisition on dose reduction were assessed. Image quality was evaluated on the basis of image noise and signal to noise ratio (SNR). The dose reduction values achieved in pediatric phantoms were remarkably lower than those achieved for the adult. The efficiency of the AEC is decreased at 80 kVp compared to higher tube potentials and for helical scans following an anterior posterior (AP-AEC) compared to a lateral (LAT-AEC) topogram acquisition. In AP-AEC scans, the dose reduction ranged between 4.7 and 34.7% for neonate, 15.4 and 30.9% for 1 year old, 3.1 and 26.7% for 5 years old, 1.2 and 58.7% for 10 years old, and 15.5 and 57.4% for adult. In LAT-AEC scans, the corresponding dose reduction ranged between 11.0 and 36.5%, 27.2 and 35.7%, 11.3 and 35.6%, 0.3 and 67.0%, and 15.0 and 61.7%, respectively. AP-AEC scans resulted in a 17.1% and 19.7% dose increase in the thorax of neonate and the pelvis of the 10-year old phantom, respectively. The variation in the measured noise among images obtained along the scanning z axis was lower in AEC activated compared to fixed milliamperes scans. However, image noise was significantly increased (P<.001) and SNR significantly decreased (P<.001) in most AEC activated compared to fixed milliamperes scans. In conclusion, AEC resulted in a (i

  3. Biplane interventional pediatric system with cone-beam CT: dose and image quality characterization for the default protocols.

    Science.gov (United States)

    Corredoira, Eva; Vañó, Eliseo; Alejo, Luis; Ubeda, Carlos; Gutiérrez-Larraya, Federico; Garayoa, Julia

    2016-07-08

    The aim of this study was to assess image quality and radiation dose of a biplane angiographic system with cone-beam CT (CBCT) capability tuned for pediatric cardiac procedures. The results of this study can be used to explore dose reduction techniques. For pulsed fluoroscopy and cine modes, polymethyl methacrylate phantoms of various thicknesses and a Leeds TOR 18-FG test object were employed. Various fields of view (FOV) were selected. For CBCT, the study employed head and body dose phantoms, Catphan 504, and an anthropomorphic cardiology phantom. The study also compared two 3D rotational angiography protocols. The entrance surface air kerma per frame increases by a factor of 3-12 when comparing cine and fluoroscopy frames. The biggest difference in the signal-to- noise ratio between fluoroscopy and cine modes occurs at FOV 32 cm because fluoroscopy is acquired at a 1440 × 1440 pixel matrix size and in unbinned mode, whereas cine is acquired at 720 × 720 pixels and in binned mode. The high-contrast spatial resolution of cine is better than that of fluoroscopy, except for FOV 32 cm, because fluoroscopy mode with 32 cm FOV is unbinned. Acquiring CBCT series with a 16 cm head phantom using the standard dose protocol results in a threefold dose increase compared with the low-dose protocol. Although the amount of noise present in the images acquired with the low-dose protocol is much higher than that obtained with the standard mode, the images present better spatial resolution. A 1 mm diameter rod with 250 Hounsfield units can be distinguished in reconstructed images with an 8 mm slice width. Pediatric-specific protocols provide lower doses while maintaining sufficient image quality. The system offers a novel 3D imaging mode. The acquisition of CBCT images results in increased doses administered to the patients, but also provides further diagnostic information contained in the volumetric images. The assessed CBCT protocols provide images that are noisy, but with

  4. 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

  5. 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.

  6. Improvement of the temporal resolution of cardiac CT reconstruction algorithms using an optimized filtering step

    International Nuclear Information System (INIS)

    Roux, S.; Desbat, L.; Koenig, A.; Grangeat, P.

    2005-01-01

    In this paper we study a property of the filtering step of multi-cycle reconstruction algorithm used in the field of cardiac CT. We show that the common filtering step procedure is not optimal in the case of divergent geometry and decrease slightly the temporal resolution. We propose to use the filtering procedure related to the work of Noo at al ( F.Noo, M. Defrise, R. Clakdoyle, and H. Kudo. Image reconstruction from fan-beam projections on less than a short-scan. Phys. Med.Biol., 47:2525-2546, July 2002)and show that this alternative allows to reach the optimal temporal resolution with the same computational effort. (N.C.)

  7. 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.

  8. Improving best-phase image quality in cardiac CT by motion correction with MAM optimization

    Energy Technology Data Exchange (ETDEWEB)

    Rohkohl, Christopher; Bruder, Herbert; Stierstorfer, Karl [Siemens AG, Healthcare Sector, Siemensstrasse 1, 91301 Forchheim (Germany); Flohr, Thomas [Siemens AG, Healthcare Sector, Siemensstrasse 1, 91301 Forchheim (Germany); Institute of Diagnostic Radiology, Eberhard Karls University, Hoppe-Seyler-Str. 3, 72076 Tuebingen (Germany)

    2013-03-15

    Purpose: Research in image reconstruction for cardiac CT aims at using motion correction algorithms to improve the image quality of the coronary arteries. The key to those algorithms is motion estimation, which is currently based on 3-D/3-D registration to align the structures of interest in images acquired in multiple heart phases. The need for an extended scan data range covering several heart phases is critical in terms of radiation dose to the patient and limits the clinical potential of the method. Furthermore, literature reports only slight quality improvements of the motion corrected images when compared to the most quiet phase (best-phase) that was actually used for motion estimation. In this paper a motion estimation algorithm is proposed which does not require an extended scan range but works with a short scan data interval, and which markedly improves the best-phase image quality. Methods: Motion estimation is based on the definition of motion artifact metrics (MAM) to quantify motion artifacts in a 3-D reconstructed image volume. The authors use two different MAMs, entropy, and positivity. By adjusting the motion field parameters, the MAM of the resulting motion-compensated reconstruction is optimized using a gradient descent procedure. In this way motion artifacts are minimized. For a fast and practical implementation, only analytical methods are used for motion estimation and compensation. Both the MAM-optimization and a 3-D/3-D registration-based motion estimation algorithm were investigated by means of a computer-simulated vessel with a cardiac motion profile. Image quality was evaluated using normalized cross-correlation (NCC) with the ground truth template and root-mean-square deviation (RMSD). Four coronary CT angiography patient cases were reconstructed to evaluate the clinical performance of the proposed method. Results: For the MAM-approach, the best-phase image quality could be improved for all investigated heart phases, with a maximum

  9. Improving best-phase image quality in cardiac CT by motion correction with MAM optimization

    International Nuclear Information System (INIS)

    Rohkohl, Christopher; Bruder, Herbert; Stierstorfer, Karl; Flohr, Thomas

    2013-01-01

    Purpose: Research in image reconstruction for cardiac CT aims at using motion correction algorithms to improve the image quality of the coronary arteries. The key to those algorithms is motion estimation, which is currently based on 3-D/3-D registration to align the structures of interest in images acquired in multiple heart phases. The need for an extended scan data range covering several heart phases is critical in terms of radiation dose to the patient and limits the clinical potential of the method. Furthermore, literature reports only slight quality improvements of the motion corrected images when compared to the most quiet phase (best-phase) that was actually used for motion estimation. In this paper a motion estimation algorithm is proposed which does not require an extended scan range but works with a short scan data interval, and which markedly improves the best-phase image quality. Methods: Motion estimation is based on the definition of motion artifact metrics (MAM) to quantify motion artifacts in a 3-D reconstructed image volume. The authors use two different MAMs, entropy, and positivity. By adjusting the motion field parameters, the MAM of the resulting motion-compensated reconstruction is optimized using a gradient descent procedure. In this way motion artifacts are minimized. For a fast and practical implementation, only analytical methods are used for motion estimation and compensation. Both the MAM-optimization and a 3-D/3-D registration-based motion estimation algorithm were investigated by means of a computer-simulated vessel with a cardiac motion profile. Image quality was evaluated using normalized cross-correlation (NCC) with the ground truth template and root-mean-square deviation (RMSD). Four coronary CT angiography patient cases were reconstructed to evaluate the clinical performance of the proposed method. Results: For the MAM-approach, the best-phase image quality could be improved for all investigated heart phases, with a maximum

  10. QbD for pediatric oral lyophilisates development: risk assessment followed by screening and optimization.

    Science.gov (United States)

    Casian, Tibor; Iurian, Sonia; Bogdan, Catalina; Rus, Lucia; Moldovan, Mirela; Tomuta, Ioan

    2017-12-01

    This study proposed the development of oral lyophilisates with respect to pediatric medicine development guidelines, by applying risk management strategies and DoE as an integrated QbD approach. Product critical quality attributes were overviewed by generating Ishikawa diagrams for risk assessment purposes, considering process, formulation and methodology related parameters. Failure Mode Effect Analysis was applied to highlight critical formulation and process parameters with an increased probability of occurrence and with a high impact on the product performance. To investigate the effect of qualitative and quantitative formulation variables D-optimal designs were used for screening and optimization purposes. Process parameters related to suspension preparation and lyophilization were classified as significant factors, and were controlled by implementing risk mitigation strategies. Both quantitative and qualitative formulation variables introduced in the experimental design influenced the product's disintegration time, mechanical resistance and dissolution properties selected as CQAs. The optimum formulation selected through Design Space presented ultra-fast disintegration time (5 seconds), a good dissolution rate (above 90%) combined with a high mechanical resistance (above 600 g load). Combining FMEA and DoE allowed the science based development of a product with respect to the defined quality target profile by providing better insights on the relevant parameters throughout development process. The utility of risk management tools in pharmaceutical development was demonstrated.

  11. Optimal Monochromatic Energy Levels in Spectral CT Pulmonary Angiography for the Evaluation of Pulmonary Embolism

    Science.gov (United States)

    Wu, Huawei; Zhang, Qing; Hua, Jia; Hua, Xiaolan; Xu, Jianrong

    2013-01-01

    Background The aim of this study was to determine the optimal monochromatic spectral CT pulmonary angiography (sCTPA) levels to obtain the highest image quality and diagnostic confidence for pulmonary embolism detection. Methods The Institutional Review Board of the Shanghai Jiao Tong University School of Medicine approved this study, and written informed consent was obtained from all participating patients. Seventy-two patients with pulmonary embolism were scanned with spectral CT mode in the arterial phase. One hundred and one sets of virtual monochromatic spectral (VMS) images were generated ranging from 40 keV to 140 keV. Image noise, clot diameter and clot to artery contrast-to-noise ratio (CNR) from seven sets of VMS images at selected monochromatic levels in sCTPA were measured and compared. Subjective image quality and diagnostic confidence for these images were also assessed and compared. Data were analyzed by paired t test and Wilcoxon rank sum test. Results The lowest noise and the highest image quality score for the VMS images were obtained at 65 keV. The VMS images at 65 keV also had the second highest CNR value behind that of 50 keV VMS images. There was no difference in the mean noise and CNR between the 65 keV and 70 keV VMS images. The apparent clot diameter correlated with the keV levels. Conclusions The optimal energy level for detecting pulmonary embolism using dual-energy spectral CT pulmonary angiography was 65–70 keV. Virtual monochromatic spectral images at approximately 65–70 keV yielded the lowest image noise, high CNR and highest diagnostic confidence for the detection of pulmonary embolism. PMID:23667583

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  13. MO-E-17A-04: Size-Specific Dose Estimate (SSDE) Provides a Simple Method to Calculate Organ Dose for Pediatric CT Examinations

    International Nuclear Information System (INIS)

    Moore, B; Brady, S; Kaufman, R; Mirro, A

    2014-01-01

    Purpose: Investigate the correlation of SSDE with organ dose in a pediatric population. Methods: Four anthropomorphic phantoms, representing a range of pediatric body habitus, were scanned with MOSFET dosimeters placed at 23 organ locations to determine absolute organ dosimetry. Phantom organ dosimetry was divided by phantom SSDE to determine correlation between organ dose and SSDE. Correlation factors were then multiplied by patient SSDE to estimate patient organ dose. Patient demographics consisted of 352 chest and 241 abdominopelvic CT examinations, 22 ± 15 kg (range 5−55 kg) mean weight, and 6 ± 5 years (range 4 mon to 23 years) mean age. Patient organ dose estimates were compared to published pediatric Monte Carlo study results. Results: Phantom effective diameters were matched with patient population effective diameters to within 4 cm. 23 organ correlation factors were determined in the chest and abdominopelvic region across nine pediatric weight subcategories. For organs fully covered by the scan volume, correlation in the chest (average 1.1; range 0.7−1.4) and abdominopelvic (average 0.9; range 0.7−1.3) was near unity. For organs that extended beyond the scan volume (i.e., skin, bone marrow, and bone surface), correlation was determined to be poor (average 0.3; range: 0.1−0.4) for both the chest and abdominopelvic regions, respectively. Pediatric organ dosimetry was compared to published values and was found to agree in the chest to better than an average of 5% (27.6/26.2) and in the abdominopelvic region to better than 2% (73.4/75.0). Conclusion: Average correlation of SSDE and organ dosimetry was found to be better than ± 10% for fully covered organs within the scan volume. This study provides a list of organ dose correlation factors for the chest and abdominopelvic regions, and describes a simple methodology to estimate individual pediatric patient organ dose based on patient SSDE

  14. MO-E-17A-04: Size-Specific Dose Estimate (SSDE) Provides a Simple Method to Calculate Organ Dose for Pediatric CT Examinations

    Energy Technology Data Exchange (ETDEWEB)

    Moore, B; Brady, S; Kaufman, R [St Jude Children' s Research Hospital, Memphis, TN (United States); Mirro, A [Washington University, St. Louis, MO (United States)

    2014-06-15

    Purpose: Investigate the correlation of SSDE with organ dose in a pediatric population. Methods: Four anthropomorphic phantoms, representing a range of pediatric body habitus, were scanned with MOSFET dosimeters placed at 23 organ locations to determine absolute organ dosimetry. Phantom organ dosimetry was divided by phantom SSDE to determine correlation between organ dose and SSDE. Correlation factors were then multiplied by patient SSDE to estimate patient organ dose. Patient demographics consisted of 352 chest and 241 abdominopelvic CT examinations, 22 ± 15 kg (range 5−55 kg) mean weight, and 6 ± 5 years (range 4 mon to 23 years) mean age. Patient organ dose estimates were compared to published pediatric Monte Carlo study results. Results: Phantom effective diameters were matched with patient population effective diameters to within 4 cm. 23 organ correlation factors were determined in the chest and abdominopelvic region across nine pediatric weight subcategories. For organs fully covered by the scan volume, correlation in the chest (average 1.1; range 0.7−1.4) and abdominopelvic (average 0.9; range 0.7−1.3) was near unity. For organs that extended beyond the scan volume (i.e., skin, bone marrow, and bone surface), correlation was determined to be poor (average 0.3; range: 0.1−0.4) for both the chest and abdominopelvic regions, respectively. Pediatric organ dosimetry was compared to published values and was found to agree in the chest to better than an average of 5% (27.6/26.2) and in the abdominopelvic region to better than 2% (73.4/75.0). Conclusion: Average correlation of SSDE and organ dosimetry was found to be better than ± 10% for fully covered organs within the scan volume. This study provides a list of organ dose correlation factors for the chest and abdominopelvic regions, and describes a simple methodology to estimate individual pediatric patient organ dose based on patient SSDE.

  15. 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

  16. 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)

  17. SU-E-I-86: Ultra-Low Dose Computed Tomography Attenuation Correction for Pediatric PET CT Using Adaptive Statistical Iterative Reconstruction (ASiR™)

    Energy Technology Data Exchange (ETDEWEB)

    Brady, S; Shulkin, B [St. Jude Children’s Research Hospital, Memphis, TN (United States)

    2015-06-15

    Purpose: To develop ultra-low 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 ultra-low doses (10–35 mAs). CT quantitation: noise, low-contrast resolution, and CT numbers for eleven tissue substitutes were analyzed in-phantom. CT quantitation was analyzed to a reduction of 90% CTDIvol (0.39/3.64; mGy) radiation dose 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 (SUVbw) of various diameter targets (range 8–37 mm), background uniformity, and spatial resolution. Radiation organ dose, as derived from patient exam size specific dose estimate (SSDE), was converted to effective dose using the standard ICRP report 103 method. Effective dose and CTAC noise magnitude were compared for 140 patient examinations (76 post-ASiR implementation) to determine relative patient population dose reduction and noise control. Results: CT numbers were constant to within 10% from the non-dose reduced CTAC image down to 90% dose reduction. No change in SUVbw, background percent uniformity, or spatial resolution for PET images reconstructed with CTAC protocols reconstructed with ASiR and down to 90% dose reduction. Patient population effective dose analysis demonstrated relative CTAC dose reductions between 62%–86% (3.2/8.3−0.9/6.2; mSv). Noise magnitude in dose-reduced patient images increased but was not statistically different from pre dose-reduced patient images. Conclusion: Using ASiR allowed for aggressive reduction in CTAC dose with no change in PET reconstructed images while maintaining sufficient image quality for co

  18. Research of protocols for optimization of exposure dose in abdominopelic CT

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Dong Hee [Dept. of Radiological Science, Far East University, Eumseong (Korea, Republic of)

    2017-06-15

    This study measured the exposure dose during abdominal-pelvic CT exam which occupies 70% of CT exam and tried to propose a protocol for optimized exposure dose in abdomen and pelvis without affecting the imagery interpretation. The study scanned abdomen-pelvis using the current clinical scan method, the 120 kVp, auto exposure control(AEC), as 1 phase. As for the newly proposed 2 phase scan method, the study divided into 1 phase abdomen exam and 2 phase pelvis exam and each conducted tube voltage 120 kVp, AEC for abdomen exam, and fixed tube current method in 120 kVp, 100, 150, 200, 250, 300, 350, 400 mA for pelvis exam. The exposure dose value was compared using CTDIVOL, DLP value measured during scan, and average value of CT attenuation coefficient, noise, SNR from each scan image were obtained to evaluate the image. As for the result, scanning of 2 phase showed significant difference compared to 1 phase. In CTDIVOL value, the 2 phase showed 26% decrease in abdomen, 1.8∼59.5% decrease in pelvis for 100∼250 mA, 12.7%∼30% increase in pelvis for 300∼400 mA. Also, DLP value showed 53% decrease in abdomen and 41∼81% decrease in pelvis when scanned by 2 phase compared to 1 phase, but it was not statistically significant. As for the SNR, when scanning 2 phase close to heart, scanning 1 phase close to pelvis, scanning and scanning 1 phase at upper and lower abdomen, it was higher when scanning 2 phase for 200∼ 250 mA. Also, the CT number and noise was overall similar, but the noise was high close to pelvis. However, when scanning 2 phase for 250 mA close to pelvis, the noise value came out similar to 1 phase, and did not show statistically significant difference. It seems when separating pelvis to scan in 250 mA rather than 400 mA in 1 phase as before, it is expected to have reduced effect of exposure dose without difference in the quality of image. Thus, for patients who often get abdominal-pelvic CT exam, fertile women or children, this study proposes 2

  19. Abdominal and Pelvic CT

    Medline Plus

    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 ...

  20. Evaluation of optimal scan duration and end time in cerebral CT perfusion study

    International Nuclear Information System (INIS)

    Hirata, Masaaki; Sugawara, Yoshifumi; Miki, Hitoshi; Mochizuki, Teruhito; Murase, Kenya

    2005-01-01

    The purpose of this study was to evaluate the optimal end time of scanning and the influence of varying the number of source images adopted for calculation of the parameter values in computerized tomography (CT) perfusion. Nineteen CT perfusion studies in 14 patients with cerebrovascular disease were retrospectively analyzed. CT perfusion scanning was performed using continuous scans of 1 sec/rotation x 60 sec with 5-mm-thick sections. To determine the appropriate end time of scanning, the time-density curves (TDCs) of the anterior cerebral artery (ACA), superior sagittal sinus (SSS), and basal ganglia were analyzed. The functional maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were retrospectively generated from various numbers (30, 35, 40, 45, 50, 55, and 60) of source images. Defining the values calculated from the number of source images equal to the end time of the first pass as standard values, the percentage difference between the standard values and the values generated from various numbers of sources were evaluated. The TDCs of SSS showed the latest end time of the first pass (mean, 38.6±5.2 sec; range, 32 to 48 sec). Therefore, the values calculated from the number of source images equal to the end time of the first pass of SSS were defined as standard values. Increase and decrease of the number of source images for calculation resulted in increase of the percentage difference in every parameter value. The percentage differences ranged up to 49.6% for CBF, 48.0% for CBV, and 20.0% for MTT. Scanning until the end time of the first pass of SSS is necessary and sufficient for reliable measurement. Variable scan time based on the TDC of the SSS may be of better utility than use of fixed scan time. Further, the radiation dose could be minimized in many cases by reducing the scan time. (author)

  1. 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.)

  2. 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

  3. Multislice helical CT (MSCT) for mid-facial trauma: optimization of parameters for scanning and reconstruction

    International Nuclear Information System (INIS)

    Dammert, S.; Funke, M.; Obernauer, S.; Grabbe, E.; Merten, H.A.

    2002-01-01

    Purpose: To determine the optimal scan parameters in multislice helical CT (MSCT) of the facial bone complex for both axial scanning and multiplanar reconstructions. Material and Methods: An anthropomorphic skull phantom was examined with a MSCT. Axial scans were performed with continuously increasing collimations (4 x 1.25 - 4 x 2.5 mm), tube current (20 - 200 mA) and table speeds (3.75 mm/rot. and 7.5 mm/rot.). Multiplanar reconstructions in coronal and parasagittal planes with different reconstruction increment and slice thickness were evaluated in terms of image noise, contour artifacts and visualisation of anatomical structures. Results: The best image quality was obtained with a collimation of 4 x 1.25 mm and a - table speed of 3.75 mm/rot. A reconstruction increment of 0.6 mm achieved the best time to image quality relation. With these parameters the bone structures were depicted in an optimal way without artifacts. The tube current could be reduced to 50 mA without significant loss of image quality. The optimized protocol was used for regular routine examinations in patients with facial trauma (n = 66). Conclusions: Low-dose MSCT using thin collimation, low table speed and small reconstruction increments provides excellent data for both axial images and multiplanar reconstructions in patients with facial trauma. An additional examination in coronal orientation is therefore no longer necessary. (orig.) [de

  4. Automatic selection of optimal systolic and diastolic reconstruction windows for dual-source CT coronary angiography

    International Nuclear Information System (INIS)

    Seifarth, H.; Puesken, M.; Wienbeck, S.; Maintz, D.; Heindel, W.; Juergens, K.U.; Fischbach, R.

    2009-01-01

    The aim of this study was to assess the performance of a motion-map algorithm that automatically determines optimal reconstruction windows for dual-source coronary CT angiography. In datasets from 50 consecutive patients, optimal systolic and diastolic reconstruction windows were determined using the motion-map algorithm. For manual determination of the optimal reconstruction window, datasets were reconstructed in 5% steps throughout the RR interval. Motion artifacts were rated for each major coronary vessel using a five-point scale. Mean motion scores using the motion-map algorithm were 2.4 ± 0.8 for systolic reconstructions and 1.9 ± 0.8 for diastolic reconstructions. Using the manual approach, overall motion scores were significantly better (1.9 ± 0.5 and 1.7 ± 0.6, p 90% of cases using either approach. Using the automated approach, there was a negative correlation between heart rate and motion scores for systolic reconstructions (ρ = -0.26, p 80 bpm (systolic reconstruction). (orig.)

  5. Optimal reconstructed section thickness for the detection of liver lesions with multidetector CT

    International Nuclear Information System (INIS)

    Soo, G.; Lau, K.K.; Yik, T.; Kutschera, P.

    2010-01-01

    Aim: To evaluate the impact of different reconstructed section thicknesses on liver lesion detection using multidetector computed tomography (CT). Methods: Fifty-three patients were examined using a 16-section CT machine with axial reconstructions provided at 2.5, 5, 7.5, and 10 mm section thicknesses. Images of different reconstructed section thicknesses from different patients were presented in random order to three independent, blinded radiologists for review at multiple sessions. All images were then reviewed by three radiologists in a common session. Consensus was reached following review of the previous interpretation results and results of follow-up imaging regarding the number of true liver lesions (n = 101) for comparison. Results: Mean detection rates were as follows: 93/101 lesions detected with the 2.5 mm section thickness, 98/101 lesions detected at the 5 mm section thickness, 78/101 lesions detected at the 7.5 mm section thickness, and 54/101 lesions detected at the 10 mm section thickness. Lesions missed at the 2.5 mm section thickness were due to masking by image noise. There was particular difficulty detecting subcapsular lesions and lesions adjacent to fissures or the gall bladder at the 7.5 mm and 10 mm section thicknesses. Conclusion: The optimal reconstructed section thickness for lesion detection in the liver was 5 mm.

  6. Optimization of dual-energy CT acquisitions for proton therapy using projection-based decomposition.

    Science.gov (United States)

    Vilches-Freixas, Gloria; Létang, Jean Michel; Ducros, Nicolas; Rit, Simon

    2017-09-01

    Dual-energy computed tomography (DECT) has been presented as a valid alternative to single-energy CT to reduce the uncertainty of the conversion of patient CT numbers to proton stopping power ratio (SPR) of tissues relative to water. The aim of this work was to optimize DECT acquisition protocols from simulations of X-ray images for the treatment planning of proton therapy using a projection-based dual-energy decomposition algorithm. We have investigated the effect of various voltages and tin filtration combinations on the SPR map accuracy and precision, and the influence of the dose allocation between the low-energy (LE) and the high-energy (HE) acquisitions. For all spectra combinations, virtual CT projections of the Gammex phantom were simulated with a realistic energy-integrating detector response model. Two situations were simulated: an ideal case without noise (infinite dose) and a realistic situation with Poisson noise corresponding to a 20 mGy total central dose. To determine the optimal dose balance, the proportion of LE-dose with respect to the total dose was varied from 10% to 90% while keeping the central dose constant, for four dual-energy spectra. SPR images were derived using a two-step projection-based decomposition approach. The ranges of 70 MeV, 90 MeV, and 100 MeV proton beams onto the adult female (AF) reference computational phantom of the ICRP were analytically determined from the reconstructed SPR maps. The energy separation between the incident spectra had a strong impact on the SPR precision. Maximizing the incident energy gap reduced image noise. However, the energy gap was not a good metric to evaluate the accuracy of the SPR. In terms of SPR accuracy, a large variability of the optimal spectra was observed when studying each phantom material separately. The SPR accuracy was almost flat in the 30-70% LE-dose range, while the precision showed a minimum slightly shifted in favor of lower LE-dose. Photon noise in the SPR images (20 mGy dose

  7. Optimization in the relation between image quality and patient dose in head CT

    International Nuclear Information System (INIS)

    Perez-Diaz, M.; Paz-Viera, J.E.; Carvalho Filho, A.E.; Andrade, M.E.A.; Khoury, H.J.

    2013-01-01

    Thirty-two head CT scans were acquired employing an anthropomorphic phantom containing lesions in the posterior fossa, using 2 scanners: Siemens Sensation with 64 slices and Philips Brilliance with 6 slices. Parameters as tube current (mA), slice thickness (mm), collimation (mm), tube potential (kVp) and dynamic range were changed during studies, looking for the optimal acquisition/processing conditions which permit both good lesion detectability and the lowest dose. The CT air kerma index (mGy) was measured with a pencil ionization chamber. Image quality was analyzed by 5 radiologists using a 5 points-scale criteria (1=poor, 2=fair, 3=good, 4=very good, 5=excellent) and also using 5 figure of merit in the spatial and frequency domains: Contrast (C [%]), Contrast to Noise Ratio (CNR), Signal to Noise Ratio (SNR), Normalized Mean Square Error (NMSE) and Spectral Distance (SD). Objective and subjective results were correlated. We observed that doses could be reduced by up to 25% respect to the usual practice with both scanners, mainly reducing the mAs, without affecting lesion detection. As a result, we propose an optimized protocol for each scanner as follow: 250 mAs, 120 kVp and the collimation of 6 slices x 1.50 mm per rotation the same reconstructed slice thickness to detect the lesions in the posterior fossa with good image quality for the Philips Brilliance 6, while 150 mAs, 100 kVp, collimation of 30 x 1.2 mm and reconstructed slice thickness of 3.0 mm were needed with the Siemens Sensation 64. (author)

  8. Abnormality of the spinal column in pediatric patients with lumbosacral spinal lipoma with special reference to CT findings of the lamina defects

    International Nuclear Information System (INIS)

    Yoshifuji, Kazuhisa; Ochi, Satoko; Koyanagi, Izumi; Houkin, Kiyohiro

    2009-01-01

    Lumbosacral spinal lipomas are usually associated with occult spinal dysraphism at the lumbosacral spine. During childfood, posterior arch defects in the lumbosacral spine are considered normal computed tomography (CT) findings because of the presence of interlaminar synchondrosis. In this study, we investigated the CT findings of the lumbosacral spine in the pediatric patients with lumbosacral spinal lipomas. We aimed to characterize the radiological features of the abnormal spinal column in case of spinal lipomas. Twenty-one patients (age, 1 month to 3 years) were enrolled in this study: 11 patients had conus lipoma; 10 patients, filum lipoma. All patients showed lamina defects of the lumbosacral spine on 3D-CT. The number of the defective laminae was significantly larger in the patients with conus lipomas than in those with filum lipomas. Although the appearance of lamina defects in the patients with filum lipoma was similar to the reported findings of defective laminae in normal children, these patients were characterized by mild scoliosis and asymmetry of the posterior arches localized in the lower sacrum and coccyx. On the other hand, the patients with conus lipoma were characterized by wider lamina defects that extended rostrally, 'open-door like' deformity of lamina, vertebral dysgenesis, thoracolumber scoliosis and heterotopic ossification. Such CT characterization of the abnormality of the lumbosacral spine in lipoma patients will be useful to differentiate the pathological spina bifida from the normal open posterior arches in childhood. (author)

  9. Biplane interventional pediatric system with cone‐beam CT: dose and image quality characterization for the default protocols

    Science.gov (United States)

    Vañó, Eliseo; Alejo, Luis; Ubeda, Carlos; Gutiérrez‐Larraya, Federico; Garayoa, Julia

    2016-01-01

    The aim of this study was to assess image quality and radiation dose of a biplane angiographic system with cone‐beam CT (CBCT) capability tuned for pediatric cardiac procedures. The results of this study can be used to explore dose reduction techniques. For pulsed fluoroscopy and cine modes, polymethyl methacrylate phantoms of various thicknesses and a Leeds TOR 18‐FG test object were employed. Various fields of view (FOV) were selected. For CBCT, the study employed head and body dose phantoms, Catphan 504, and an anthropomorphic cardiology phantom. The study also compared two 3D rotational angiography protocols. The entrance surface air kerma per frame increases by a factor of 3–12 when comparing cine and fluoroscopy frames. The biggest difference in the signal‐to‐noise ratio between fluoroscopy and cine modes occurs at FOV 32 cm because fluoroscopy is acquired at a 1440×1440 pixel matrix size and in unbinned mode, whereas cine is acquired at 720×720 pixels and in binned mode. The high‐contrast spatial resolution of cine is better than that of fluoroscopy, except for FOV 32 cm, because fluoroscopy mode with 32 cm FOV is unbinned. Acquiring CBCT series with a 16 cm head phantom using the standard dose protocol results in a threefold dose increase compared with the low‐dose protocol. Although the amount of noise present in the images acquired with the low‐dose protocol is much higher than that obtained with the standard mode, the images present better spatial resolution. A 1 mm diameter rod with 250 Hounsfield units can be distinguished in reconstructed images with an 8 mm slice width. Pediatric‐specific protocols provide lower doses while maintaining sufficient image quality. The system offers a novel 3D imaging mode. The acquisition of CBCT images results in increased doses administered to the patients, but also provides further diagnostic information contained in the volumetric images. The assessed CBCT protocols provide images that are noisy

  10. Radiation dose optimization in pediatric temporal bone computed tomography: influence of tube tension on image contrast and image quality.

    Science.gov (United States)

    Nauer, Claude Bertrand; Zubler, Christoph; Weisstanner, Christian; Stieger, Christof; Senn, Pascal; Arnold, Andreas

    2012-03-01

    The purpose of this experimental study was to investigate the effect of tube tension reduction on image contrast and image quality in pediatric temporal bone computed tomography (CT). Seven lamb heads with infant-equivalent sizes were scanned repeatedly, using four tube tensions from 140 to 80 kV while the CT-Dose Index (CTDI) was held constant. Scanning was repeated with four CTDI values from 30 to 3 mGy. Image contrast was calculated for the middle ear as the Hounsfield unit (HU) difference between bone and air and for the inner ear as the HU difference between bone and fluid. The influence of tube tension on high-contrast detail delineation was evaluated using a phantom. The subjective image quality of eight middle and inner ear structures was assessed using a 4-point scale (scores 1-2 = insufficient; scores 3-4 = sufficient). Middle and inner ear contrast showed a near linear increase with tube tension reduction (r = -0.94/-0.88) and was highest at 80 kV. Tube tension had no influence on spatial resolution. Subjective image quality analysis showed significantly better scoring at lower tube tensions, with highest image quality at 80 kV. However, image quality improvement was most relevant for low-dose scans. Image contrast in the temporal bone is significantly higher at low tube tensions, leading to a better subjective image quality. Highest contrast and best quality were found at 80 kV. This image quality improvement might be utilized to further reduce the radiation dose in pediatric low-dose CT protocols.

  11. Radiation dose optimization in pediatric temporal bone computed tomography: influence of tube tension on image contrast and image quality

    International Nuclear Information System (INIS)

    Nauer, Claude Bertrand; Zubler, Christoph; Weisstanner, Christian; Stieger, Christof; Senn, Pascal; Arnold, Andreas

    2012-01-01

    The purpose of this experimental study was to investigate the effect of tube tension reduction on image contrast and image quality in pediatric temporal bone computed tomography (CT). Seven lamb heads with infant-equivalent sizes were scanned repeatedly, using four tube tensions from 140 to 80 kV while the CT-Dose Index (CTDI) was held constant. Scanning was repeated with four CTDI values from 30 to 3 mGy. Image contrast was calculated for the middle ear as the Hounsfield unit (HU) difference between bone and air and for the inner ear as the HU difference between bone and fluid. The influence of tube tension on high-contrast detail delineation was evaluated using a phantom. The subjective image quality of eight middle and inner ear structures was assessed using a 4-point scale (scores 1-2 = insufficient; scores 3-4 = sufficient). Middle and inner ear contrast showed a near linear increase with tube tension reduction (r = -0.94/-0.88) and was highest at 80 kV. Tube tension had no influence on spatial resolution. Subjective image quality analysis showed significantly better scoring at lower tube tensions, with highest image quality at 80 kV. However, image quality improvement was most relevant for low-dose scans. Image contrast in the temporal bone is significantly higher at low tube tensions, leading to a better subjective image quality. Highest contrast and best quality were found at 80 kV. This image quality improvement might be utilized to further reduce the radiation dose in pediatric low-dose CT protocols. (orig.)

  12. Optimal timing of image acquisition for arterial first pass CT myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Pelgrim, G.J., E-mail: g.j.pelgrim@umcg.nl [University of Groningen, University Medical Center Groningen, Center for Medical Imaging North East Netherlands (CMI-nen), Hanzeplein 1, 9713 GZ Groningen (Netherlands); Nieuwenhuis, E.R., E-mail: e.r.nieuwenhuis@student.utwente.nl [University of Groningen, University Medical Center Groningen, Center for Medical Imaging North East Netherlands (CMI-nen), Hanzeplein 1, 9713 GZ Groningen (Netherlands); University of Twente, P.O. Box 217, 7500 AE, Enschede (Netherlands); Duguay, T.M., E-mail: duguay@musc.edu [Medical University of South Carolina, Dept. of Radiology, 25 Courtenay Drive, SC 29425, Charleston (United States); Geest, R.J. van der, E-mail: R.J.van_der_Geest@lumc.nl [Leiden University Medical Center, Dept. of Radiology, Postbus 9600, 2300 RC, Leiden (Netherlands); Varga-Szemes, A., E-mail: vargaasz@musc.edu [Medical University of South Carolina, Dept. of Radiology, 25 Courtenay Drive, SC 29425, Charleston (United States); Slump, C.H., E-mail: c.h.slump@utwente.nl [University of Groningen, University Medical Center Groningen, Center for Medical Imaging North East Netherlands (CMI-nen), Hanzeplein 1, 9713 GZ Groningen (Netherlands); University of Twente, P.O. Box 217, 7500 AE, Enschede (Netherlands); Fuller, S.R., E-mail: fullerst@musc.edu [Medical University of South Carolina, Dept. of Radiology, 25 Courtenay Drive, SC 29425, Charleston (United States); Oudkerk, M., E-mail: m.oudkerk@umcg.nl [University of Groningen, University Medical Center Groningen, Center for Medical Imaging North East Netherlands (CMI-nen), Hanzeplein 1, 9713 GZ Groningen (Netherlands); Schoepf, U.J., E-mail: schoepf@musc.edu [Medical University of South Carolina, Dept. of Radiology, 25 Courtenay Drive, SC 29425, Charleston (United States); and others

    2017-01-15

    Highlights: • Optimal timing of static, single-shot CT perfusion scans is important to differentiate ischemic from non-ischemic myocardial segments. • Time delay between reaching 150 and 250 HU thresholds in the ascending aorta and optimal contrast in the myocardium are 4 and 2 s, respectively. • Attenuation difference of more than 15 HU between normal and ischemic myocardium is present during approximately 8 s. - Abstract: Purpose: To determine the optimal timing of arterial first pass computed tomography (CT) myocardial perfusion imaging (CTMPI) based on dynamic CTMPI acquisitions. Methods and materials: Twenty-five patients (59 ± 8.4 years, 14 male)underwent adenosine-stress dynamic CTMPI on second-generation dual-source CT in shuttle mode (30 s at 100 kV and 300 mAs). Stress perfusion magnetic resonance imaging (MRI) was used as reference standard for differentiation of non-ischemic and ischemic segments. The left ventricle (LV) wall was manually segmented according to the AHA 16-segment model. Hounsfield units (HU) in myocardial segments and ascending (AA) and descending aorta (AD) were monitored over time. Time difference between peak AA and peak AD and peak myocardial enhancement was calculated, as well as the, time delay from fixed HU thresholds of 150 and 250 HU in the AA and AD to a minimal difference of 15 HU between normal and ischemic segments. Furthermore, the duration of the 15 HU difference between ischemic and non-ischemic segments was calculated. Results: Myocardial ischemia was observed by MRI in 10 patients (56.3 ± 9.0 years; 8 male). The delay between the maximum HU in the AA and AD and maximal HU in the non-ischemic segments was 2.8 s [2.2–4.3] and 0.0 s [0.0–2.8], respectively. Differentiation between ischemic and non-ischemic myocardial segments in CT was best during a time window of 8.6 ± 3.8 s. Time delays for AA triggering were 4.5 s [2.2–5.6] and 2.2 s [0–2.8] for the 150 HU and 250 HU thresholds, respectively. While for

  13. TH-EF-BRA-04: Individually Optimized Contrast-Enhanced 4D-CT for Radiotherapy Simulation in Pancreatic Ductal Adenocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Choi, W; Xue, M; Lane, B; Patel, K; Regine, W; Wang, J; Chen, S; D’souza, W; Lu, W [University of Maryland School of Medicine, Baltimore, MD (United States); Kang, M [Kyungpook National University School of Medicine, Daegu (Korea, Republic of); Klahr, P [Philips Healthcare, Highland Heights, OH (United States)

    2016-06-15

    Purpose: To develop an individually optimized contrast-enhanced (CE) 4D-CT for radiotherapy simulation in pancreatic ductal adenocarcinomas (PDA). Methods: Ten PDA patients were enrolled. Each underwent 3 CT scans: a 4D-CT immediately following a CE 3D-CT and an individually optimized CE 4D-CT using test injection. Three physicians contoured the tumor and pancreatic tissues. We compared image quality scores, tumor volume, motion, tumor-to-pancreas contrast, and contrast-to-noise ratio (CNR) in the 3 CTs. We also evaluated interobserver variations in contouring the tumor using simultaneous truth and performance level estimation (STAPLE). Results: Average image quality scores for CE 3DCT and CE 4D-CT were comparable (4.0 and 3.8, respectively; P=0.47), and both were significantly better than that for 4D-CT (2.6, P<0.001). Tumor-to-pancreas contrast results were comparable in CE 3D-CT and CE 4D-CT (15.5 and 16.7 HU, respectively; P=0.71), and the latter was significantly higher than in 4D-CT (9.2 HU, P=0.03). Image noise in CE 3D-CT (12.5 HU) was significantly lower than in CE 4D-CT (22.1 HU, P<0.001) and 4D-CT (19.4 HU, P=0.005). CNRs were comparable in CE 3D-CT and CE 4DCT (1.4 and 0.8, respectively; P=0.23), and the former was significantly better than in 4D-CT (0.6, P = 0.04). Mean tumor volumes were smaller in CE 3D-CT (29.8 cm{sup 3}) and CE 4D-CT (22.8 cm{sup 3}) than in 4D-CT (42.0 cm{sup 3}), although these differences were not statistically significant. Mean tumor motion was comparable in 4D-CT and CE 4D-CT (7.2 and 6.2 mm, P=0.23). Interobserver variations were comparable in CE 3D-CT and CE 4D-CT (Jaccard index 66.0% and 61.9%, respectively) and were worse for 4D-CT (55.6%) than CE 3D-CT. Conclusion: CE 4D-CT demonstrated characteristics comparable to CE 3D-CT, with high potential for simultaneously delineating the tumor and quantifying tumor motion with a single scan. Supported in part by Philips Healthcare.

  14. 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.

  15. TH-E-209-02: Dose Monitoring and Protocol Optimization: The Pediatric Perspective

    International Nuclear Information System (INIS)

    MacDougall, R.

    2016-01-01

    Radiation dose monitoring solutions have opened up new opportunities for medical physicists to be more involved in modern clinical radiology practices. In particular, with the help of comprehensive radiation dose data, data-driven protocol management and informed case follow up are now feasible. Significant challenges remain however and the problems faced by medical physicists are highly heterogeneous. Imaging systems from multiple vendors and a wide range of vintages co-exist in the same department and employ data communication protocols that are not fully standardized or implemented making harmonization complex. Many different solutions for radiation dose monitoring have been implemented by imaging facilities over the past few years. Such systems are based on commercial software, home-grown IT solutions, manual PACS data dumping, etc., and diverse pathways can be used to bring the data to impact clinical practice. The speakers will share their experiences with creating or tailoring radiation dose monitoring/management systems and procedures over the past few years, which vary significantly in design and scope. Topics to cover: (1) fluoroscopic dose monitoring and high radiation event handling from a large academic hospital; (2) dose monitoring and protocol optimization in pediatric radiology; and (3) development of a home-grown IT solution and dose data analysis framework. Learning Objectives: Describe the scope and range of radiation dose monitoring and protocol management in a modern radiology practice Review examples of data available from a variety of systems and how it managed and conveyed. Reflect on the role of the physicist in radiation dose awareness.

  16. TH-E-209-02: Dose Monitoring and Protocol Optimization: The Pediatric Perspective

    Energy Technology Data Exchange (ETDEWEB)

    MacDougall, R. [Boston Children’s Hospital (United States)

    2016-06-15

    Radiation dose monitoring solutions have opened up new opportunities for medical physicists to be more involved in modern clinical radiology practices. In particular, with the help of comprehensive radiation dose data, data-driven protocol management and informed case follow up are now feasible. Significant challenges remain however and the problems faced by medical physicists are highly heterogeneous. Imaging systems from multiple vendors and a wide range of vintages co-exist in the same department and employ data communication protocols that are not fully standardized or implemented making harmonization complex. Many different solutions for radiation dose monitoring have been implemented by imaging facilities over the past few years. Such systems are based on commercial software, home-grown IT solutions, manual PACS data dumping, etc., and diverse pathways can be used to bring the data to impact clinical practice. The speakers will share their experiences with creating or tailoring radiation dose monitoring/management systems and procedures over the past few years, which vary significantly in design and scope. Topics to cover: (1) fluoroscopic dose monitoring and high radiation event handling from a large academic hospital; (2) dose monitoring and protocol optimization in pediatric radiology; and (3) development of a home-grown IT solution and dose data analysis framework. Learning Objectives: Describe the scope and range of radiation dose monitoring and protocol management in a modern radiology practice Review examples of data available from a variety of systems and how it managed and conveyed. Reflect on the role of the physicist in radiation dose awareness.

  17. 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.)

  18. The optimal dose of the contrast media for spiral CT portography

    International Nuclear Information System (INIS)

    Zhang Jiansheng; Xiao Peiyu; Meng Xiaochun; Xu Chuan

    2007-01-01

    Objective: To investigate the optimal dose of the contrast media in SCTP. Methods: 40 healthy patients were divided into 2 groups according to their body weight (20 cases in group A with weight below 60kg, 20 cases in group B with weight over 70kg). They all received 90ml contrast media at a rate of 4.0 ml/sec in the contrast-enhanced CT ex- amination. And non-cirrhosis cases, liver cirrhosis without ascites cases and liver cirrhosis with ascites cases were selected respectively, 60 patients in each group. Then, the patients of each group were randomly divided into 3 sub-groups, 20 cases in each of them, which respectively received 1.5ml/kg, 2.0ml/kg, 2.5ml/kg contrast media at a rate of 4.0 ml/sec in the contrast-enhanced CT examination. The effect of the dose of the contrast material on the imaging quality of portal vein system in patients with different weight and different state of illness was analyzed. Results: In 40 healthy patients, the density difference between portal vein and hepatic parenchyma was significantly higher in Group A than in Group B (P 0.05), and both of them showed significant difference while using 1.5ml/kg contrast media (P 0.05), and they both had significant difference when using 1.5ml/kg contrast media (P< 0.05). Besides these, the imaging quality of portal vein branches and collateral vessels were better in 2.0ml/kg group than others. Conclusion: The patient's body weight and the state of liver disease influenced the extent of portal vein enhancement. To calculate the dose of contrast media according to patient's weight is crucial for ensuring the imaging quality of portal vein system. 2.0ml/kg contrast media can provide a better effect. (authors)

  19. HECTOR: A 240kV micro-CT setup optimized for research

    Science.gov (United States)

    Masschaele, Bert; Dierick, Manuel; Van Loo, Denis; Boone, Matthieu N.; Brabant, Loes; Pauwels, Elin; Cnudde, Veerle; Van Hoorebeke, Luc

    2013-10-01

    X-ray micro-CT has become a very powerful and common tool for non-destructive three-dimensional (3D) visualization and analysis of objects. Many systems are commercially available, but they are typically limited in terms of operational freedom both from a mechanical point of view as well as for acquisition routines. HECTOR is the latest system developed by the Ghent University Centre for X-ray Tomography (http://www.ugct.ugent.be) in collaboration with X-Ray Engineering (XRE bvba, Ghent, Belgium). It consists of a mechanical setup with nine motorized axes and a modular acquisition software package and combines a microfocus directional target X-ray source up to 240 kV with a large flat-panel detector. Provisions are made to install a line-detector for a maximal operational range. The system can accommodate samples up to 80 kg, 1 m long and 80 cm in diameter while it is also suited for high resolution (down to 4 μm) tomography. The bi-directional detector tiling is suited for large samples while the variable source-detector distance optimizes the signal to noise ratio (SNR) for every type of sample, even with peripheral equipment such as compression stages or climate chambers. The large vertical travel of 1 m can be used for helical scanning and a vertical detector rotation axis allows laminography experiments. The setup is installed in a large concrete bunker to allow accommodation of peripheral equipment such as pumps, chillers, etc., which can be integrated in the modular acquisition software to obtain a maximal correlation between the environmental control and the CT data taken. The acquisition software does not only allow good coupling with the peripheral equipment but its scripting feature is also particularly interesting for testing new and exotic acquisition routines.

  20. Estimation of diastolic filling pressure with cardiac CT in comparison with echocardiography using tissue doppler imaging: Determination of optimal CT reconstruction parameters

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Ji Sun; Suh, Jon; Lee, Heon [Soonchunhyang University Hospital Bucheon, Bucheon (Korea, Republic of); Lee, Bora [Dept. of Biostatistics, Soonchunhyang University College of Medicine, Seoul (Korea, Republic of); Lee, Soo Jeong [Terarecon Korea, Seoul (Korea, Republic of); Jou, Sung Shick [Dept. of Radiology, Soonchunhyang University Hospital Cheonan, Cheonan (Korea, Republic of); Lim, Hyun Kyung [Dept. of Radiology, Soonchunhyang University Hospital Seoul, Seoul (Korea, Republic of)

    2017-08-01

    To determine the optimal CT image reconstruction parameters for the measurement of early transmitral peak velocity (E), early peak mitral septal tissue velocity (E′), and E / E′. Forty-six patients underwent simultaneous cardiac CT and echocardiography on the same day. Four CT datasets were reconstructed with a slice thickness/interval of 0.9/0.9 mm or 3/3 mm at 10 (10% RR-interval) or 20 (5% RR-interval) RR-intervals. The E was calculated by dividing the peak transmitral flow (mL/s) by the corresponding mitral valve area (cm{sup 2}). E′ was calculated from the changes in the left ventricular length per cardiac phase. E / E′ was then estimated and compared with that from echocardiography. For assessment of E / E′, CT and echocardiography were more strongly correlated (p < 0.05) with a slice thickness of 0.9 mm and 5% RR-interval (r = 0.77) than with 3 mm or 10% RR-interval. The diagnostic accuracy of predicting elevated filling pressure (E / E′ ≥ 13, n = 14) was better with a slice thickness of 0.9 mm and 5% RR-interval (87.0%) than with 0.9 mm and 10% RR-interval (71.7%) (p = 0.123) and significantly higher than that with a slice thickness of 3 mm with 5% (67.4%) and 10% RR-interval (63.0%), (p < 0.05), respectively. Data reconstruction with a slice thickness of 0.9 mm at 5% RR-interval is superior to that with a slice thickness of 3 mm or 10% RR-interval in terms of the correlation of E / E′ between CT and echocardiography. Thin slices and frequent sampling also allow for more accurate prediction of elevated filling pressure.

  1. Spiral CT and optimization of the modalities of the iodinated intravenous contrast material: Experimental studies in human pathology

    International Nuclear Information System (INIS)

    Bonaldi, V.

    1998-01-01

    Spiral (or helical) CT represents the most recent improvement in the field of computed assisted tomography (CAT scan). The capabilities of this new imaging modality are much superior to these of conventional CT scanning; then result from the rapid acquisition and from the volumetric nature of the derived data set. The short time of data acquisition had made mandatory the revision of protocols for intravenous administration of iodinated contrast material. By the means of several studies, carried out on pathologic and healthy patients, we have attempted to improve knowledge in factors influencing CT attenuation values after injection of contrast material, in the aim of improving contrast administration performed during spiral CT scanning. Anatomical landmarks that we have studied till now have been liver, the pancreas, the kidney and the cervical spine. In addition, a paired based methodology has been used. The volumetric set of data derived from spiral CT scanning leads to optimal post-processing tasks, the most interesting being related to cine-display and multiplanar reformatting; both modalities have been evaluated, about the pancreas and the musculo-skeletal system respectively. Conversely, this new modality, as for other imaging modalities, is responsible for additional costs derived from restless increase in the number of images to be dealt with and from the occurrence of new tasks (in post-processing particularly). The place of spiral CT in diagnostic strategies among other modern imaging modalities should be assessed, especially with respect to Magnetic Resonance Imaging (MRI). (author)

  2. Automated selection of the optimal cardiac phase for single-beat coronary CT angiography reconstruction

    International Nuclear Information System (INIS)

    Stassi, D.; Ma, H.; Schmidt, T. G.; Dutta, S.; Soderman, A.; Pazzani, D.; Gros, E.; Okerlund, D.

    2016-01-01

    Purpose: Reconstructing a low-motion cardiac phase is expected to improve coronary artery visualization in coronary computed tomography angiography (CCTA) exams. This study developed an automated algorithm for selecting the optimal cardiac phase for CCTA reconstruction. The algorithm uses prospectively gated, single-beat, multiphase data made possible by wide cone-beam imaging. The proposed algorithm differs from previous approaches because the optimal phase is identified based on vessel image quality (IQ) directly, compared to previous approaches that included motion estimation and interphase processing. Because there is no processing of interphase information, the algorithm can be applied to any sampling of image phases, making it suited for prospectively gated studies where only a subset of phases are available. Methods: An automated algorithm was developed to select the optimal phase based on quantitative IQ metrics. For each reconstructed slice at each reconstructed phase, an image quality metric was calculated based on measures of circularity and edge strength of through-plane vessels. The image quality metric was aggregated across slices, while a metric of vessel-location consistency was used to ignore slices that did not contain through-plane vessels. The algorithm performance was evaluated using two observer studies. Fourteen single-beat cardiac CT exams (Revolution CT, GE Healthcare, Chalfont St. Giles, UK) reconstructed at 2% intervals were evaluated for best systolic (1), diastolic (6), or systolic and diastolic phases (7) by three readers and the algorithm. Pairwise inter-reader and reader-algorithm agreement was evaluated using the mean absolute difference (MAD) and concordance correlation coefficient (CCC) between the reader and algorithm-selected phases. A reader-consensus best phase was determined and compared to the algorithm selected phase. In cases where the algorithm and consensus best phases differed by more than 2%, IQ was scored by three

  3. How I do it-optimizing radiofrequency ablation in spinal metastases using iCT and navigation.

    Science.gov (United States)

    Kavakebi, Pujan; Freyschlag, C F; Thomé, C

    2017-10-01

    Exact positioning of the radiofrequency ablation (RFA) probe for tumor treatment under fluoroscopic guidance can be difficult because of potentially small inaccessible lesions and the radiation dose to the medical staff in RFA. In addition, vertebroplasty (VP) can be significantly high. Description and workflow of RFA in spinal metastasis using iCT (intraoperative computed tomography) and 3D-navigation-based probe placement followed by VP. RFA and VP can be successfully combined with iCT-based navigation, which leads to a reduction of radiation to the staff and optimal probe positioning due to 3D navigation.

  4. Leukemia and brain tumors among children after radiation exposure from CT scans: design and methodological opportunities of the Dutch Pediatric CT Study

    NARCIS (Netherlands)

    Meulepas, Johanna M.; Ronckers, Cécile M.; Smets, Anne M. J. B.; Nievelstein, Rutger A. J.; Jahnen, Andreas; Lee, Choonsik; Kieft, Mariëtte; Laméris, Johan S.; van Herk, Marcel; Greuter, Marcel J. W.; Jeukens, Cécile R. L. P. N.; van Straten, Marcel; Visser, Otto; van Leeuwen, Flora E.; Hauptmann, Michael

    2014-01-01

    Computed tomography (CT) scans are indispensable in modern medicine; however, the spectacular rise in global use coupled with relatively high doses of ionizing radiation per examination have raised radiation protection concerns. Children are of particular concern because they are more sensitive to

  5. Leukemia and brain tumors among children after radiation exposure from CT scans : design and methodological opportunities of the Dutch Pediatric CT Study

    NARCIS (Netherlands)

    Meulepas, Johanna M.; Ronckers, Cecile M.; Smets, Anne M. J. B.; Nievelstein, Rutger A. J.; Jahnen, Andreas; Lee, Choonsik; Kieft, Mariette; Lameris, Johan S.; van Herk, Marcel; Greuter, Marcel J. W.; Jeukens, Cecile R. L. P. N.; van Straten, Marcel; Visser, Otto; van Leeuwen, Flora E.; Hauptmann, Michael

    Computed tomography (CT) scans are indispensable in modern medicine; however, the spectacular rise in global use coupled with relatively high doses of ionizing radiation per examination have raised radiation protection concerns. Children are of particular concern because they are more sensitive to

  6. Accelerated barrier optimization compressed sensing (ABOCS) for CT reconstruction with improved convergence

    International Nuclear Information System (INIS)

    Niu, Tianye; Fruhauf, Quentin; Petrongolo, Michael; Zhu, Lei; Ye, Xiaojing

    2014-01-01

    Recently, we proposed a new algorithm of accelerated barrier optimization compressed sensing (ABOCS) for iterative CT reconstruction. The previous implementation of ABOCS uses gradient projection (GP) with a Barzilai–Borwein (BB) step-size selection scheme (GP-BB) to search for the optimal solution. The algorithm does not converge stably due to its non-monotonic behavior. In this paper, we further improve the convergence of ABOCS using the unknown-parameter Nesterov (UPN) method and investigate the ABOCS reconstruction performance on clinical patient data. Comparison studies are carried out on reconstructions of computer simulation, a physical phantom and a head-and-neck patient. In all of these studies, the ABOCS results using UPN show more stable and faster convergence than those of the GP-BB method and a state-of-the-art Bregman-type method. As shown in the simulation study of the Shepp–Logan phantom, UPN achieves the same image quality as those of GP-BB and the Bregman-type methods, but reduces the iteration numbers by up to 50% and 90%, respectively. In the Catphan©600 phantom study, a high-quality image with relative reconstruction error (RRE) less than 3% compared to the full-view result is obtained using UPN with 17% projections (60 views). In the conventional filtered-backprojection reconstruction, the corresponding RRE is more than 15% on the same projection data. The superior performance of ABOCS with the UPN implementation is further demonstrated on the head-and-neck patient. Using 25% projections (91 views), the proposed method reduces the RRE from 21% as in the filtered backprojection (FBP) results to 7.3%. In conclusion, we propose UPN for ABOCS implementation. As compared to GP-BB and the Bregman-type methods, the new method significantly improves the convergence with higher stability and fewer iterations. (paper)

  7. Optimization of a fast optical CT scanner for nPAG gel dosimetry

    Science.gov (United States)

    Vandecasteele, Jan; DeDeene, Yves

    2009-05-01

    A fast laser scanning optical CT scanner was constructed and optimized at the Ghent university. The first images acquired were contaminated with several imaging artifacts. The origins of the artifacts were investigated. Performance characteristics of different components were measured such as the laser spot size, light attenuation by the lenses and the dynamic range of the photo-detector. The need for a differential measurement using a second photo-detector was investigated. Post processing strategies to compensate for hardware related errors were developed. Drift of the laser and of the detector was negligible. Incorrectly refractive index matching was dealt with by developing an automated matching process. When scratches on the water bath and phantom container are present, these pose a post processing challenge to eliminate the resulting artifacts from the reconstructed images Secondary laser spots due to multiple reflections need to be further investigated. The time delay in the control of the galvanometer and detector was dealt with using black strips that serve as markers of the projection position. Still some residual ringing artifacts are present. Several small volumetric test phantoms were constructed to obtain an overall picture of the accuracy.

  8. Optimized enhancement in helical CT: Experiences with a real-time bolus tracking system in 628 patients

    International Nuclear Information System (INIS)

    Kirchner, J.; Kickuth, R.; Laufer, U.; Noack, M.; Liermann, D.

    2000-01-01

    AIMS: Ultrafast detector technology enables bolus-triggered application of contrast media. In a prospective study we investigated the benefit of this new method with the intention of optimizing enhancement during examination of the chest and abdomen. MATERIALS AND METHODS: In total, we examined 548 patients under standardized conditions. All examinations were performed on a Somatom Plus 4 Power CT system (Siemens Corp., Forchheim, Germany) using the CARE-Bolus software. This produces repetitive low-dose test images (e.g. for the lung: 140 kV, 43 mA, TI 0.5 s) and measures the Hounsfield attenuation in a pre-selected region of interest. After exceeding a defined threshold, a diagnostic spiral CT examination was begun automatically. The data obtained from 321 abdominal CT and 179 lung CT examinations were correlated with different parameters such as age, weight and height of the patients and parameters of vascular access. In a group of 80 patients, the injection of contrast medium was stopped after reaching a pre-defined threshold of an increase of 100 HU over the baseline. Then, we assessed the maximal enhancement of liver, pulmonal artery trunk and aortic arch. RESULTS: There was no correlation between bolus geometry and age, body surface or weight. In helical CT of the abdomen the threshold was reached after a mean trigger time of 27 s (range 13-67 s) and only 65 ml (range 41-105 ml) of contrast medium were administered. In helical CT of the lung the threshold was reached after 21 s (range 12-48 s) and the mean amount of administered contrast medium was 48 ml (range 38-71 ml). CONCLUSION: Bolus triggering allows optimized enhancement of the organs and reduces the dose of contrast material required compared with standard administration. Kirchner, J. (2000). Clinical Radiology 55, 368-373

  9. Optimized enhancement in helical CT: experiences with a real-time bolus tracking system in 628 patients.

    Science.gov (United States)

    Kirchner, J; Kickuth, R; Laufer, U; Noack, M; Liermann, D

    2000-05-01

    Ultrafast detector technology enables bolus-triggered application of contrast media. In a prospective study we investigated the benefit of this new method with the intention of optimizing enhancement during examination of the chest and abdomen. In total, we examined 548 patients under standardized conditions. All examinations were performed on a Somatom Plus 4 Power CT system (Siemens Corp., Forchheim, Germany) using the CARE-Bolus software. This produces repetitive low-dose test images (e.g. for the lung: 140 kV, 43 mA, TI 0.5 s) and measures the Hounsfield attenuation in a pre-selected region of interest. After exceeding a defined threshold, a diagnostic spiral CT examination was begun automatically. The data obtained from 321 abdominal CT and 179 lung CT examinations were correlated with different parameters such as age, weight and height of the patients and parameters of vascular access. In a group of 80 patients, the injection of contrast medium was stopped after reaching a pre-defined threshold of an increase of 100 HU over the baseline. Then, we assessed the maximal enhancement of liver, pulmonal artery trunk and aortic arch. There was no correlation between bolus geometry and age, body surface or weight. In helical CT of the abdomen the threshold was reached after a mean trigger time of 27 s (range 13-67 s) and only 65 ml (range 41-105 ml) of contrast medium were administered. In helical CT of the lung the threshold was reached after 21 s (range 12-48 s) and the mean amount of administered contrast medium was 48 ml (range 38-71 ml). Bolus triggering allows optimized enhancement of the organs and reduces the dose of contrast material required compared with standard administration. Copyright 2000 The Royal College of Radiologists.

  10. Physical performance and image optimization of megavoltage cone-beam CT

    Energy Technology Data Exchange (ETDEWEB)

    Morin, Olivier; Aubry, Jean-Francois; Aubin, Michele; Chen, Josephine; Descovich, Martina; Hashemi, Ali-Bani; Pouliot, Jean [Department of Radiation Oncology, Helen Diller Comprehensive Cancer Center, University of California San Francisco, San Francisco, California 94143 and UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, California 94158 (United States); Department of Radiation Oncology, Helen Diller Comprehensive Cancer Center, University of California San Francisco, San Francisco, California 94143 (United States); Siemens Oncology Care Systems, Concord, California 94520 (United States); Department of Radiation Oncology, Helen Diller Comprehensive Cancer Center, University of California San Francisco, San Francisco, California 94143 and UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, California 94158 (United States)

    2009-04-15

    Megavoltage cone-beam CT (MVCBCT) is the most recent addition to the in-room CT systems developed for image-guided radiation therapy. The first generation MVCBCT system consists of a 6 MV treatment x-ray beam produced by a conventional linear accelerator equipped with a flat panel amorphous silicon detector. The objective of this study was to evaluate the physical performance of MVCBCT in order to optimize the system acquisition and reconstruction parameters for image quality. MVCBCT acquisitions were performed with the clinical system but images were reconstructed and analyzed with a separate research workstation. The geometrical stability and the positioning accuracy of the system were evaluated by comparing geometrical calibrations routinely performed over a period of 12 months. The beam output and detector intensity stability during MVCBCT acquisition were also evaluated by analyzing in-air acquisitions acquired at different exposure levels. Several system parameters were varied to quantify their impact on image quality including the exposure (2.7, 4.5, 9.0, 18.0, and 54.0 MU), the craniocaudal imaging length (2, 5, 15, and 27.4 cm), the voxel size (0.5, 1, and 2 mm), the slice thickness (1, 3, and 5 mm), and the phantom size. For the reconstruction algorithm, the study investigated the effect of binning, averaging and diffusion filtering of raw projections as well as three different projection filters. A head-sized water cylinder was used to measure and improve the uniformity of MVCBCT images. Inserts of different electron densities were placed in a water cylinder to measure the contrast-to-noise ratio (CNR). The spatial resolution was obtained by measuring the point-spread function of the system using an iterative edge blurring technique. Our results showed that the geometric stability and accuracy of MVCBCT were better than 1 mm over a period of 12 months. Beam intensity variations per projection of up to 35.4% were observed for a 2.7 MU MVCBCT acquisition

  11. Study of dosimetry CT in Skull for pediatric patients; Estudio de dosimetria TC en craneo para pacientes pediatricos

    Energy Technology Data Exchange (ETDEWEB)

    Ramos Amores, D.; Serna Berna, A.; Mata Colodro, F.; Puchades Puchades, V.

    2013-07-01

    The dose that receiving the patients in CT studies is the highest that can be received in a study of Radiology. If patients are children and we do studies with the same parameters as adults, they will receive a higher dose of radiation. This work seeks to expose the result of a dosimetric study on CT for children aged 0-15, carried out at the Hospital General Universitario de Santa Lucia in Cartagena during the year 2012. (Author)

  12. Thoracic lymph node station recognition on CT images based on automatic anatomy recognition with an optimal parent strategy

    Science.gov (United States)

    Xu, Guoping; Udupa, Jayaram K.; Tong, Yubing; Cao, Hanqiang; Odhner, Dewey; Torigian, Drew A.; Wu, Xingyu

    2018-03-01

    Currently, there are many papers that have been published on the detection and segmentation of lymph nodes from medical images. However, it is still a challenging problem owing to low contrast with surrounding soft tissues and the variations of lymph node size and shape on computed tomography (CT) images. This is particularly very difficult on low-dose CT of PET/CT acquisitions. In this study, we utilize our previous automatic anatomy recognition (AAR) framework to recognize the thoracic-lymph node stations defined by the International Association for the Study of Lung Cancer (IASLC) lymph node map. The lymph node stations themselves are viewed as anatomic objects and are localized by using a one-shot method in the AAR framework. Two strategies have been taken in this paper for integration into AAR framework. The first is to combine some lymph node stations into composite lymph node stations according to their geometrical nearness. The other is to find the optimal parent (organ or union of organs) as an anchor for each lymph node station based on the recognition error and thereby find an overall optimal hierarchy to arrange anchor organs and lymph node stations. Based on 28 contrast-enhanced thoracic CT image data sets for model building, 12 independent data sets for testing, our results show that thoracic lymph node stations can be localized within 2-3 voxels compared to the ground truth.

  13. Is dual-phase abdominal CT necessary for the optimal detection of metastases from renal cell carcinoma?

    International Nuclear Information System (INIS)

    Jain, Y.; Liew, S.; Taylor, M.B.; Bonington, S.C.

    2011-01-01

    Aim: To determine whether dual-phase abdominal computed tomography (CT) detected more metastases than portal-phase CT alone in patients with renal cell carcinoma (RCC). Materials and methods: Audit committee approval was obtained. A retrospective audit was undertaken in 100 patients who underwent both arterial and portal phase CT. The CT images were independently reviewed by two consultant radiologists. The presence of metastases in the liver, pancreas, and contralateral kidney were recorded for each phase of contrast enhancement. Results: Metastases were identified in the liver in 27 patients, pancreas in 12, and contralateral kidney in 23 patients. Nine of the 27 (33%) liver metastases, three of the 12 (25%) pancreatic metastases, and two of the 23 (9%) renal metastases were only detected in the arterial phase, whilst four of the 27 (15%) liver metastases, three of the 12 (25%) pancreatic metastases, and two of the 23 (9%) renal metastases were only detected in the portal phase. Nine patients (9%) had metastases only visualized in the arterial phase, and six (6%) only in the portal phase. Detection of metastases only visible in the arterial phase led to a change of management in two patients (2%). Conclusion: The audit results support our current standard of dual-phase abdominal CT for optimal detection of RCC metastases.

  14. An optimization-based method for geometrical calibration in cone-beam CT without dedicated phantoms

    International Nuclear Information System (INIS)

    Panetta, D; Belcari, N; Guerra, A Del; Moehrs, S

    2008-01-01

    In this paper we present a new method for the determination of geometrical misalignments in cone-beam CT scanners, from the analysis of the projection data of a generic object. No a priori knowledge of the object shape and positioning is required. We show that a cost function, which depends on the misalignment parameters, can be defined using the projection data and that such a cost function has a local minimum in correspondence to the actual parameters of the system. Hence, the calibration of the scanner can be carried out by minimizing the cost function using standard optimization techniques. The method is developed for a particular class of 3D object functions, for which the redundancy of the fan beam sinogram in the transaxial midplane can be extended to cone-beam projection data, even at wide cone angles. The method has an approximated validity for objects which do not belong to that class; in that case, a suitable subset of the projection data can be selected in order to compute the cost function. We show by numerical simulations that our method is capable to determine with high accuracy the most critical misalignment parameters of the scanner, i.e., the transversal shift and the skew of the detector. Additionally, the detector slant can be determined. Other parameters such as the detector tilt, the longitudinal shift and the error in the source-detector distance cannot be determined with our method, as the proposed cost function has a very weak dependence on them. However, due to the negligible influence of these latter parameters in the reconstructed image quality, they can be kept fixed at estimated values in both calibration and reconstruction processes without compromising the final result. A trade-off between computational cost and calibration accuracy must be considered when choosing the data subset used for the computation of the cost function. Results on real data of a mouse femur as obtained with a small animal micro-CT are shown as well, proving

  15. Pediatric CT dose reduction for suspected appendicitis: a practice quality improvement project using artificial Gaussian noise--part 1, computer simulations.

    Science.gov (United States)

    Callahan, Michael J; Kleinman, Patricia L; Strauss, Keith J; Bandos, Andriy; Taylor, George A; Tsai, Andy; Kleinman, Paul K

    2015-01-01

    The purpose of this study was to develop a departmental practice quality improvement project to systematically reduce CT doses for the evaluation of suspected pediatric appendicitis by introducing computer-generated gaussian noise. Two hundred MDCT abdominopelvic examinations of patients younger than 20 years performed with girth-based scanning parameters for suspected appendicitis were reviewed. Two judges selected 45 examinations in which the diagnosis of appendicitis was excluded (14, appendix not visualized; 31, normal appendix visualized). Gaussian noise was introduced into axial image series, creating five additional series acquired at 25-76% of the original dose. Two readers reviewed 270 image series for appendix visualization (4-point Likert scale and arrow localization). Volume CT dose index (CTDIvol) and size-specific dose estimate (SSDE) were calculated by use of patient girth. Confidence ratings and localization accuracy were analyzed with mixed models and nonparametric bootstrap analysis at a 0.05 significance level. The mean baseline SSDE for the 45 patients was 16 mGy (95% CI, 12-20 mGy), and the corresponding CTDIvol was 10 mGy (95% CI, 4-16 mGy). Changes in correct appendix localization frequencies were minor. There was no substantial trend with decreasing simulated dose level (p = 0.46). Confidence ratings decreased with increasing dose reduction (p = 0.007). The average decreases were -0.27 for the 25% simulated dose (p = 0.01), -0.17 for 33% (p = 0.03), and -0.03 for 43% (p = 0.65). Pediatric abdominal MDCT can be performed with 43% of the original dose (SSDE, 7 mGy; CTDIvol, 4.3 mGy) without substantially affecting visualization of a normal appendix.

  16. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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 ...