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  1. Article ; Online: Development of pediatric CT protocols for specific scanners: why bother?

    Cody, Dianna D

    Pediatric radiology

    2014  Volume 44 Suppl 3, Page(s) 489–491

    Abstract: When determining a strategy for pediatric CT scanning, clinical staff can either elect to adjust routine adult-protocol parameter settings on a case-by-case basis or rely on pre-set pediatric protocol parameters. The advantages of the latter approach are ...

    Abstract When determining a strategy for pediatric CT scanning, clinical staff can either elect to adjust routine adult-protocol parameter settings on a case-by-case basis or rely on pre-set pediatric protocol parameters. The advantages of the latter approach are the topic of this manuscript. This paper outlines specific options to consider, including the need for regular protocol review.
    MeSH term(s) Algorithms ; Child ; Equipment Failure Analysis/instrumentation ; Equipment Failure Analysis/standards ; Guideline Adherence ; Humans ; Patient-Centered Care/standards ; Pediatrics/standards ; Practice Guidelines as Topic ; Radiation Dosage ; Radiology/standards ; Radiometry/instrumentation ; Radiometry/standards ; Reference Values ; Tomography, X-Ray Computed/instrumentation ; Tomography, X-Ray Computed/standards ; United States
    Language English
    Publishing date 2014-10-11
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 124459-0
    ISSN 1432-1998 ; 0301-0449
    ISSN (online) 1432-1998
    ISSN 0301-0449
    DOI 10.1007/s00247-014-3136-4
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Management of auto exposure control during pediatric computed tomography.

    Cody, Dianna D

    Pediatric radiology

    2014  Volume 44 Suppl 3, Page(s) 427–430

    Abstract: Automatic exposure control (AEC) is particularly well-suited for pediatric CT scanning. However the importance of the localizer scan portion of exams that relies on AEC is frequently underestimated. This paper explains in detail several crucial aspects ... ...

    Abstract Automatic exposure control (AEC) is particularly well-suited for pediatric CT scanning. However the importance of the localizer scan portion of exams that relies on AEC is frequently underestimated. This paper explains in detail several crucial aspects of the localizer and their effect on the subsequent cross-sectional (axial or helical) image acquisition. The paper also covers general suggestions regarding AEC influence on the cross-sectional images. AEC systems on CT scanners are becoming more complex; using them effectively in the setting of pediatric CT requires careful selection of scan parameters.
    MeSH term(s) Child ; Equipment Design ; Equipment Failure Analysis ; Humans ; Image Enhancement/instrumentation ; Image Enhancement/methods ; Patient Positioning/instrumentation ; Patient Positioning/methods ; Pediatrics/instrumentation ; Pediatrics/methods ; Radiation Dosage ; Radiation Protection/instrumentation ; Radiation Protection/methods ; Radiometry/instrumentation ; Radiometry/methods ; Tomography, X-Ray Computed/instrumentation ; Tomography, X-Ray Computed/methods
    Language English
    Publishing date 2014-10-11
    Publishing country Germany
    Document type Journal Article ; Review
    ZDB-ID 124459-0
    ISSN 1432-1998 ; 0301-0449
    ISSN (online) 1432-1998
    ISSN 0301-0449
    DOI 10.1007/s00247-014-3140-8
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: A comparison of breast and lung doses from chest CT scans using organ-based tube current modulation (OBTCM) vs. Automatic tube current modulation (ATCM).

    Layman, Rick R / Hardy, Anthony J / Kim, Hyun J / Chou, Ei Ne / Bostani, Maryam / Cagnon, Chris / Cody, Dianna / McNitt-Gray, Michael

    Journal of applied clinical medical physics

    2021  Volume 22, Issue 5, Page(s) 97–109

    Abstract: ... as water equivalent diameter (D: Results: Mean dose reduction from OBTCM in nD: Conclusions: One ...

    Abstract Purpose: The purpose of this work was to estimate and compare breast and lung doses of chest CT scans using organ-based tube current modulation (OBTCM) to those from conventional, attenuation-based automatic tube current modulation (ATCM) across a range of patient sizes.
    Methods: Thirty-four patients (17 females, 17 males) who underwent clinically indicated CT chest/abdomen/pelvis (CAP) examinations employing OBTCM were collected from two multi-detector row CT scanners. Patient size metric was assessed as water equivalent diameter (D
    Results: Mean dose reduction from OBTCM in nD
    Conclusions: One specific manufacturer's OBTCM was analyzed. OBTCM was observed to significantly decrease normalized breast relative to a modeled version of that same manufacturer's ATCM scheme. However, significant dose savings were not observed in lung dose over all. Results from this study support the use of OBTCM chest protocols for females only.
    MeSH term(s) Breast/diagnostic imaging ; Female ; Humans ; Lung/diagnostic imaging ; Male ; Monte Carlo Method ; Phantoms, Imaging ; Radiation Dosage ; Tomography, X-Ray Computed
    Language English
    Publishing date 2021-05-03
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2010347-5
    ISSN 1526-9914 ; 1526-9914
    ISSN (online) 1526-9914
    ISSN 1526-9914
    DOI 10.1002/acm2.13198
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: AAPM Medical Physics Practice Guideline 1.b: CT protocol management and review practice guideline.

    Cody, Dianna D / Dillon, Chad M / Fisher, Tyler S / Liu, Xinming / McNitt-Gray, Michael F / Patel, Vikas

    Journal of applied clinical medical physics

    2021  Volume 22, Issue 6, Page(s) 4–10

    Abstract: The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education and professional practice of medical physics. The AAPM has more than 8000 members and is the ... ...

    Abstract The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education and professional practice of medical physics. The AAPM has more than 8000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines will be reviewed for the purpose of revision or renewal, as appropriate, on their fifth anniversary or sooner. Each medical physics practice guideline represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and effective use of diagnostic and therapeutic radiology requires specific training, skills, and techniques, as described in each document. Reproduction or modification of the published practice guidelines and technical standards by those entities not providing these services is not authorized. The following terms are used in the AAPM practice guidelines: (a) Must and Must Not: Used to indicate that adherence to the recommendation is considered necessary to conform to this practice guideline. (b) Should and Should Not: Used to indicate a prudent practice to which exceptions may occasionally be made in appropriate circumstances.
    MeSH term(s) Cytarabine ; Health Physics ; Humans ; Radiation Oncology ; Societies ; Tomography, X-Ray Computed ; United States
    Chemical Substances Cytarabine (04079A1RDZ)
    Language English
    Publishing date 2021-05-03
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2010347-5
    ISSN 1526-9914 ; 1526-9914
    ISSN (online) 1526-9914
    ISSN 1526-9914
    DOI 10.1002/acm2.13193
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  5. Article ; Online: Partial arc beam filtration: a novel approach to reducing CT breast radiation dose.

    Mathieu, Kelsey B / Cody, Dianna D

    AJR. American journal of roentgenology

    2013  Volume 200, Issue 3, Page(s) 601–607

    Abstract: Objective: We sought to assess the effectiveness of a novel CT radiation dose reduction strategy in which filtration was added at the x-ray tube output port between the x-ray beam and the breast area of three sizes of anthropomorphic phantoms.: ... ...

    Abstract Objective: We sought to assess the effectiveness of a novel CT radiation dose reduction strategy in which filtration was added at the x-ray tube output port between the x-ray beam and the breast area of three sizes of anthropomorphic phantoms.
    Materials and methods: To evaluate the dose-reduction potential of partial arc x-ray beam filtration, copper foil filtration or lead foil filtration was placed over CT scanners' covers when scanning anthropomorphic phantoms representative of a 5-year-old child, a 10-year-old child, and an adult female. Dose reduction was calculated as the percentage difference between the mean entrance radiation dose (on the phantoms' surfaces at locations representing the sternum and left breast) in unshielded scans compared with the mean dose in scans shielded by copper or lead foil. We also compared the CT numbers and noise sampled in regions representing the lung and the soft tissues near the sternum, left breast, and spine in CT images of the phantoms during unshielded scans relative to acquisitions shielded by copper or lead foil.
    Results: Entrance dose at the sternum and left breast in the three anthropomorphic phantoms was reduced by 28-66% and 54-79% when using copper or lead foil filtration, respectively. However, copper foil filtration affected the CT numbers and noise in the CT images less than the lead foil filtration did (8.2% vs 32% mean increase in noise).
    Conclusion: By incorporating partial arc beam filtration into CT scanners, substantial dose reductions may be achieved with a minimal increase in image noise.
    MeSH term(s) Adult ; Breast ; Child ; Child, Preschool ; Equipment Design ; Equipment Failure Analysis ; Female ; Filtration/instrumentation ; Humans ; Male ; Phantoms, Imaging ; Radiation Dosage ; Radiation Protection/instrumentation ; Radiation Protection/methods ; Tomography, X-Ray Computed/instrumentation ; Tomography, X-Ray Computed/methods
    Language English
    Publishing date 2013-02-22
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 82076-3
    ISSN 1546-3141 ; 0361-803X ; 0092-5381
    ISSN (online) 1546-3141
    ISSN 0361-803X ; 0092-5381
    DOI 10.2214/AJR.12.8771
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Development of a dual-energy computed tomography quality control program: Characterization of scanner response and definition of relevant parameters for a fast-kVp switching dual-energy computed tomography system.

    Nute, Jessica L / Jacobsen, Megan C / Stefan, Wolfgang / Wei, Wei / Cody, Dianna D

    Medical physics

    2018  Volume 45, Issue 4, Page(s) 1444–1458

    Abstract: Purpose: A prototype QC phantom system and analysis process were developed to characterize the spectral capabilities of a fast kV-switching dual-energy computed tomography (DECT) scanner. This work addresses the current lack of quantitative oversight ... ...

    Abstract Purpose: A prototype QC phantom system and analysis process were developed to characterize the spectral capabilities of a fast kV-switching dual-energy computed tomography (DECT) scanner. This work addresses the current lack of quantitative oversight for this technology, with the goal of identifying relevant scan parameters and test metrics instrumental to the development of a dual-energy quality control (DEQC).
    Methods: A prototype elliptical phantom (effective diameter: 35 cm) was designed with multiple material inserts for DECT imaging. Inserts included tissue equivalent and material rods (including iodine and calcium at varying concentrations). The phantom was scanned on a fast kV-switching DECT system using 16 dual-energy acquisitions (CTDIvol range: 10.3-62 mGy) with varying pitch, rotation time, and tube current. The circular head phantom (22 cm diameter) was scanned using a similar protocol (12 acquisitions; CTDIvol range: 36.7-132.6 mGy). All acquisitions were reconstructed at 50, 70, 110, and 140 keV and using a water-iodine material basis pair. The images were evaluated for iodine quantification accuracy, stability of monoenergetic reconstruction CT number, noise, and positional constancy. Variance component analysis was used to identify technique parameters that drove deviations in test metrics. Variances were compared to thresholds derived from manufacturer tolerances to determine technique parameters that had a nominally significant effect on test metrics.
    Results: Iodine quantification error was largely unaffected by any of the technique parameters investigated. Monoenergetic HU stability was found to be affected by mAs, with a threshold under which spectral separation was unsuccessful, diminishing the utility of DECT imaging. Noise was found to be affected by CTDIvol in the DEQC body phantom, and CTDIvol and mA in the DEQC head phantom. Positional constancy was found to be affected by mAs in the DEQC body phantom and mA in the DEQC head phantom.
    Conclusion: A streamlined scan protocol was developed to further investigate the effects of CTDIvol and rotation time while limiting data collection to the DEQC body phantom. Further data collection will be pursued to determine baseline values and statistically based failure thresholds for the validation of long-term DECT scanner performance.
    MeSH term(s) Phantoms, Imaging ; Quality Control ; Signal-To-Noise Ratio ; Time Factors ; Tomography, X-Ray Computed/instrumentation
    Language English
    Publishing date 2018-03-15
    Publishing country United States
    Document type Journal Article
    ZDB-ID 188780-4
    ISSN 2473-4209 ; 0094-2405
    ISSN (online) 2473-4209
    ISSN 0094-2405
    DOI 10.1002/mp.12812
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  7. Article ; Online: The impact of x-ray tube stabilization on localized radiation dose in axial CT scans: initial results in CTDI phantoms.

    Mathieu, Kelsey B / McNitt-Gray, Michael F / Cody, Dianna D

    Physics in medicine and biology

    2016  Volume 61, Issue 20, Page(s) 7363–7376

    Abstract: Rise, fall, and stabilization of the x-ray tube output occur immediately before and after data acquisition on some computed tomography (CT) scanners and are believed to contribute additional dose to anatomy facing the x-ray tube when it powers on or off. ...

    Abstract Rise, fall, and stabilization of the x-ray tube output occur immediately before and after data acquisition on some computed tomography (CT) scanners and are believed to contribute additional dose to anatomy facing the x-ray tube when it powers on or off. In this study, we characterized the dose penalty caused by additional radiation exposure during the rise, stabilization, and/or fall time (referred to as overscanning). A 32 cm CT dose-index (CTDI) phantom was scanned on three CT scanners: GE Healthcare LightSpeed VCT, GE Healthcare Discovery CT750 HD, and Siemens Somatom Definition Flash. Radiation exposure was detected for various x-ray tube start acquisition angles using a 10 cm pencil ionization chamber placed in the peripheral chamber hole at the phantom's 12 o'clock position. Scan rotation time, ionization chamber location, phantom diameter, and phantom centering were varied to quantify their effects on the dose penalty caused by overscanning. For 1 s single, axial rotations, CTDI at the 12 o'clock chamber position (CTDI
    MeSH term(s) Algorithms ; Humans ; Image Processing, Computer-Assisted ; Phantoms, Imaging ; Radiation Dosage ; Tomography Scanners, X-Ray Computed ; Tomography, X-Ray Computed/instrumentation
    Language English
    Publishing date 2016-10-21
    Publishing country England
    Document type Journal Article
    ZDB-ID 208857-5
    ISSN 1361-6560 ; 0031-9155
    ISSN (online) 1361-6560
    ISSN 0031-9155
    DOI 10.1088/0031-9155/61/20/7363
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  8. Article ; Online: CT protocol review and optimization.

    Kofler, James M / Cody, Dianna D / Morin, Richard L

    Journal of the American College of Radiology : JACR

    2014  Volume 11, Issue 3, Page(s) 267–270

    Abstract: To reduce the radiation dose associated with CT scans, much attention is focused on CT protocol review and improvement. In fact, annual protocol reviews will soon be required for ACR CT accreditation. A major challenge in the protocol review process is ... ...

    Abstract To reduce the radiation dose associated with CT scans, much attention is focused on CT protocol review and improvement. In fact, annual protocol reviews will soon be required for ACR CT accreditation. A major challenge in the protocol review process is determining whether a current protocol is optimal and deciding what steps to take to improve it. In this paper, the authors describe methods for pinpointing deficiencies in CT protocols and provide a systematic approach for optimizing them. Emphasis is placed on a team approach, with a team consisting of at least one radiologist, one physicist, and one technologist. This core team completes a critical review of all aspects of a CT protocol and carefully evaluates proposed improvements. Changes to protocols are implemented only with consensus of the core team, with consideration of all aspects of the CT examination, including image quality, radiation dose, patient care and safety, and workflow.
    MeSH term(s) Practice Guidelines as Topic ; Radiation Protection/standards ; Radiographic Image Enhancement/standards ; Radiology/standards ; Tomography, X-Ray Computed/standards ; United States
    Language English
    Publishing date 2014-03
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 2274861-1
    ISSN 1558-349X ; 1546-1440
    ISSN (online) 1558-349X
    ISSN 1546-1440
    DOI 10.1016/j.jacr.2013.10.013
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  9. Article ; Online: Dual-Energy CT: Lower Limits of Iodine Detection and Quantification.

    Jacobsen, Megan C / Cressman, Erik N K / Tamm, Eric P / Baluya, Dodge L / Duan, Xinhui / Cody, Dianna D / Schellingerhout, Dawid / Layman, Rick R

    Radiology

    2019  Volume 292, Issue 2, Page(s) 414–419

    Abstract: Background Assessments of the quantitative limitations among the six commercially available dual-energy (DE) CT acquisition schemes used by major CT manufacturers could aid researchers looking to use iodine quantification as an imaging biomarker. Purpose ...

    Abstract Background Assessments of the quantitative limitations among the six commercially available dual-energy (DE) CT acquisition schemes used by major CT manufacturers could aid researchers looking to use iodine quantification as an imaging biomarker. Purpose To determine the limits of detection and quantification of DE CT in phantoms by comparing rapid peak kilovoltage switching, dual-source, split-filter, and dual-layer detector systems in six different scanners. Materials and Methods Seven 50-mL iohexol solutions were used, with concentrations of 0.03-2.0 mg iodine per milliliter. The solutions and water sample were scanned five times each in two phantoms (small, 20-cm diameter; large, 30 × 40-cm diameter) with six DE CT systems and a total of 10 peak kilovoltage settings or combinations. Iodine maps were created, and the mean iodine signal in each sample was recorded. The limit of blank (LOB) was defined as the upper limit of the 95% confidence interval of the water sample. The limit of detection (LOD) was defined as the concentration with a 95% chance of having a signal above the LOB. The limit of quantification (LOQ) was defined as the lowest concentration where the coefficient of variation was less than 20%. Results The LOD range was 0.021-0.26 mg/mL in the small phantom and 0.026-0.55 mg/mL in the large phantom. The LOQ range was 0.07-0.50 mg/mL in the small phantom and 0.20-1.0 mg/mL in the large phantom. The dual-source and rapid peak kilovoltage switching systems had the lowest LODs, and the dual-layer detector systems had the highest LODs. Conclusion The iodine limit of detection using dual-energy CT systems varied with scanner and phantom size, but all systems depicted iodine in the small and large phantoms at or below 0.3 and 0.5 mg/mL, respectively, and enabled quantification at concentrations of 0.5 and 1.0 mg/mL, respectively. © RSNA, 2019
    MeSH term(s) Contrast Media ; Iodine ; Phantoms, Imaging ; Radiographic Image Enhancement/methods ; Radiography, Dual-Energy Scanned Projection/methods ; Reproducibility of Results ; Tomography, X-Ray Computed/methods
    Chemical Substances Contrast Media ; Iodine (9679TC07X4)
    Language English
    Publishing date 2019-06-25
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 80324-8
    ISSN 1527-1315 ; 0033-8419
    ISSN (online) 1527-1315
    ISSN 0033-8419
    DOI 10.1148/radiol.2019182870
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  10. Article ; Online: "How to" incorporate dual-energy imaging into a high volume abdominal imaging practice.

    Tamm, Eric P / Le, Ott / Liu, Xinming / Layman, Rick R / Cody, Dianna D / Bhosale, Priya R

    Abdominal radiology (New York)

    2017  Volume 42, Issue 3, Page(s) 688–701

    Abstract: Dual-energy CT imaging has many potential uses in abdominal imaging. It also has unique requirements for protocol creation depending on the dual-energy scanning technique that is being utilized. It also generates several new types of images which can ... ...

    Abstract Dual-energy CT imaging has many potential uses in abdominal imaging. It also has unique requirements for protocol creation depending on the dual-energy scanning technique that is being utilized. It also generates several new types of images which can increase the complexity of image creation and image interpretation. The purpose of this article is to review, for rapid switching and dual-source dual-energy platforms, methods for creating dual-energy protocols, different approaches for efficiently creating dual-energy images, and an approach to navigating and using dual-energy images at the reading station all using the example of a pancreatic multiphasic protocol. It will also review the three most commonly used types of dual-energy images: "workhorse" 120kVp surrogate images (including blended polychromatic and 70 keV monochromatic), high contrast images (e.g., low energy monochromatic and iodine material decomposition images), and virtual unenhanced images. Recent developments, such as the ability to create automatically on the scanner the most common dual-energy images types, namely new "Mono+" images for the DSDECT (dual-source dual-energy CT) platform will also be addressed. Finally, an approach to image interpretation using automated "hanging protocols" will also be covered. Successful dual-energy implementation in a high volume practice requires careful attention to each of these steps of scanning, image creation, and image interpretation.
    MeSH term(s) Clinical Protocols ; Humans ; Radiography, Abdominal/methods ; Radiography, Dual-Energy Scanned Projection/methods ; Tomography, X-Ray Computed/methods
    Language English
    Publishing date 2017-01-09
    Publishing country United States
    Document type Journal Article ; Review
    ZDB-ID 2839786-1
    ISSN 2366-0058 ; 2366-004X
    ISSN (online) 2366-0058
    ISSN 2366-004X
    DOI 10.1007/s00261-016-1035-x
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