Paediatric head computed tomography dose values and the impact on image quality

Abstract Background The purpose of this study is to analyse paediatric head Computed Tomography (CT) examination dose values, establish local Diagnostic Reference Levels (DRL), and perform objective image quality assessment per categorisation. Methods A total of 100 paediatric head CT examinations divided into 5 paediatric age categorisations were retrospectively selected: 0–3months, 3months to 1 year, 1 to 6 years, and more than 6 years. Computed Tomography Dose Index (CTDIvol - mGy) and Dose Lenght Product (DLP – mGy.cm), acquisition mode and CT scanner were collected per examination. Examinations with lower and higher dose values per categorisation were selected, and 10 Regions of Interest (ROI’s) were defined on supra and infra tentorial regions in order to access image quality, based on signal and noise values. Local DRLs were compare with the literature and with previous studies of this centre. Results The obtained DLP values were 580, 570, 700, 754 mGy.cm, for the categorisation of 0–3 months, 3 months to 1 year, 1 to 6 years, and more than 6 years, respectively. No significant differences were founded in dose values and image quality, per paediatric categorisation. Conclusions Despise previous local DRLs were defined using a different age categorisation, some paediatric aged categorisation revealed an increase of the dose values. These results must be related with the acquisition of a new CT scanner. Optimisation process is on-going and new protocols are being define.

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THE IMPACT OF HEAD POSITIONING ON THE IMAGE QUALITY OF MULTI-DETECTOR COMPUTED TOMOGRAPHY

Biomedical Engineering Applications Basis and Communications ◽

10.4015/s1016237221500502 ◽

2021 ◽

pp. 2150050

Author(s):

Yang-Ting Hsu ◽

Jo-Chi Jao

Keyword(s):

Computed Tomography ◽

Image Quality ◽

Control Group ◽

Ct Scanner ◽

Head Ct ◽

Radiologic Technologists ◽

Head Positioning ◽

The Impact ◽

Multi Detector Computed Tomography

Radiologic technologists face various types of patients during multi-detector computed tomography (CT) examinations. In emergency departments, it is common to have patients who cannot follow instructions for the examinations. The asymmetric axial view of the head CT might affect the correctness of the clinician’s diagnosis. This study aimed to assess the impact of head positioning on the image quality of head CT using two phantoms. All scans were performed on a 16-slice CT scanner. In the control group, the tilted angle of the phantoms was 0[Formula: see text], and no multiplanar reconstruction (MPR) was performed. In the experimental groups, the tilted angles of the phantoms were 5[Formula: see text], 10[Formula: see text] and 15[Formula: see text], respectively, and MPR was performed afterwards. The results showed that if the head was tilted during the head CT examinations, image asymmetry and artifacts appeared without MPR. After MPR, one phantom showed that there were significant differences and the other phantom showed no significant differences quantitatively in image symmetry and artifacts between experimental groups and the control group, while both phantoms showed no significant differences qualitatively in image symmetry and artifacts between experimental groups and the control group. Although MPR can correct the image asymmetry and artifacts caused by tilted head positioning to some extent, it consumes time. Therefore, technologists should position the head as exactly as possible when performing head CT examinations.

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The impact of pediatric-specific dose modulation curves on radiation dose and image quality in head computed tomography

Pediatric Radiology ◽

10.1007/s00247-015-3398-5 ◽

2015 ◽

Vol 45 (12) ◽

pp. 1814-1822 ◽

Cited By ~ 5

Author(s):

Joana Santos ◽

Shane Foley ◽

Graciano Paulo ◽

Mark F. McEntee ◽

Louise Rainford

Keyword(s):

Computed Tomography ◽

Image Quality ◽

Radiation Dose ◽

Dose Modulation ◽

The Impact ◽

Head Computed Tomography

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Evaluation of Organ Dose and Image Quality Metrics of Pediatric CT Chest-Abdomen-Pelvis (CAP) Examination: An Anthropomorphic Phantom Study

Applied Sciences ◽

10.3390/app11052047 ◽

2021 ◽

Vol 11 (5) ◽

pp. 2047

Author(s):

Nor Azura Muhammad ◽

Zunaide Kayun ◽

Hasyma Abu Hassan ◽

Jeannie Hsiu Ding Wong ◽

Kwan Hoong Ng ◽

...

Keyword(s):

Image Quality ◽

Multidetector Ct ◽

Organ Dose ◽

Quality Metrics ◽

Ct Scanner ◽

Image Quality Metrics ◽

Tube Current ◽

Significant Difference ◽

Noise Ratio ◽

The Impact

The aim of this study is to investigate the impact of CT acquisition parameter setting on organ dose and its influence on image quality metrics in pediatric phantom during CT examination. The study was performed on 64-slice multidetector CT scanner (MDCT) Siemens Definition AS (Siemens Sector Healthcare, Forchheim, Germany) using various CT CAP protocols (P1–P9). Tube potential for P1, P2, and P3 protocols were fixed at 100 kVp while P4, P5, and P6 were fixed at 80 kVp with used of various reference noise values. P7, P8, and P9 were the modification of P1 with changes on slice collimation, pitch factor, and tube current modulation (TCM), respectively. TLD-100 chips were inserted into the phantom slab number 7, 9, 10, 12, 13, and 14 to represent thyroid, lung, liver, stomach, gonads, and skin, respectively. The image quality metrics, signal to noise ratio (SNR) and contrast to noise ratio (CNR) values were obtained from the CT console. As a result, this study indicates a potential reduction in the absorbed dose up to 20% to 50% along with reducing tube voltage, tube current, and increasing the slice collimation. There is no significant difference (p > 0.05) observed between the protocols and image metrics.

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Optimization of head computed tomography scan in a tertiary institution in Edo State, South-South Nigeria

Medical Science and Discovery ◽

10.36472/msd.v8i4.521 ◽

2021 ◽

Vol 8 (4) ◽

pp. 225-230

Author(s):

Chikezie Chukwuemeka Udo ◽

Akintayo Daniel Omojola ◽

Chukwuemeka Christian Nzotta

Keyword(s):

Computed Tomography ◽

Ct Scanner ◽

Tertiary Institution ◽

Dose Length Product ◽

Volume Computed Tomography ◽

The United Kingdom ◽

Ct Protocol ◽

Tube Current ◽

Edo State ◽

Computed Tomography Dose Index

Objective: The study is aimed at optimizing the existing CT protocol for head scans in a Specialist Teaching Hospital in Edo State with a 16-slice Siemens Somatom Emotion scanner. Also, the study determined the volume computed tomography dose index (CTDIvol) and Dose Length Product (DLP) from the patient's dose profiles. The results from this study were compared with relevant studies. Materials and Methods: The scanner was used to acquire head CT of 160 patients retrospectively. Also, a locally designed head phantom was used to simulate individual patients using a similar protocol by changing the tube current (mA) and total scan width (TSW) only from the existing protocol. Results: Percentage dose reduction (PDR) for the CTDIvol and DLP ranged 42.00-46.80% and 37.13-43.54% respectively. The optimized CTDIvol and DLP were lowest compared to studies in the United Kingdom (UK), Italy, India, Ireland, Sudan, Nigeria, European Commission (EC), United States of America (USA) and Japan. Only the DLP for India was lower than our optimized value. Conclusion: The need to understudy CT configuration is necessary, this will allow end-users to optimize certain parameters in the CT scanner, which will reduce the patient dose without compromising image quality

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Magnetic resonance imaging and computed tomography of equine cheek teeth and adjacent structures: comparative study of image quality in horses in vivo, post-mortem and frozen-thawed

Acta Veterinaria Scandinavica ◽

10.1186/s13028-019-0495-8 ◽

2019 ◽

Vol 61 (1) ◽

Author(s):

Christin Röttiger ◽

Maren Hellige ◽

Bernhard Ohnesorge ◽

Astrid Bienert-Zeit

Keyword(s):

Computed Tomography ◽

Image Quality ◽

Post Mortem ◽

Mr Images ◽

Adjacent Structures ◽

Group A ◽

Group B ◽

The Impact ◽

Ct And Mri

Abstract Background The use of cadavers for radiology research methodologies involving subjective image quality evaluation of anatomical criteria is well-documented. The purpose of this method comparison study was to evaluate the image quality of dental and adjacent structures in computed tomography (CT) and high-field (3 T) magnetic resonance (MR) images in cadaveric heads, based on an objective four-point rating scale. Whilst CT is a well-established technique, MR imaging (MRI) is rarely used for equine dental diagnostics. The use of a grading system in this study allowed an objective assessment of CT and MRI advantages in portraying equine cheek teeth. As imaging is commonly performed with cadaveric or frozen and thawed heads for dental research investigations, the second objective was to quantify the impact of the specimens’ conditions (in vivo, post-mortem, frozen-thawed) on the image quality in CT and MRI. Results The CT and MR images of nine horses, focused on the maxillary premolar 08s and molar 09s, were acquired post-mortem (Group A). Three observers scored the dental and adjacent tissues. Results showed that MR sequences gave an excellent depiction of endo- and periodontal structures, whereas CT produced high-quality images of the hard tooth and bony tissues. Additional CT and MRI was performed in vivo (Group B) and frozen-thawed (Group C) in three of these nine horses to specify the condition of the best specimens for further research. Assessing the impact of the specimens’ conditions on image quality, specific soft tissues of the maxillary 08s and 09s including adjacent structures (pulps, mucosa of the maxillary sinuses, periodontal ligament, soft tissue inside the infraorbital canal) were graded in group B and C and analysed for significant differences within CT and MR modalities in comparison to group A. Results showed that MRI scores in vivo were superior to the post-mortem and frozen-thawed condition. Conclusions On comparing the imaging performance of CT and MRI, both techniques show a huge potential for application in equine dentistry. Further studies are needed to assess the clinical suitability of MRI. For further research investigations it must be considered, that the best MR image quality is provided in live horses.

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ADULT CT EXAMINATIONS IN ALGERIA: TOWARDS UPDATING NATIONAL DIAGNOSTIC REFERENCE LEVELS

Radiation Protection Dosimetry ◽

10.1093/rpd/ncaa116 ◽

2020 ◽

Vol 190 (4) ◽

pp. 364-371

Author(s):

Nadia Khelassi-Toutaoui ◽

Ahmed Merad ◽

Virginia Tsapaki ◽

Fouzia Meddad ◽

Zakia Sakhri-Brahimi ◽

...

Keyword(s):

Computed Tomography ◽

Radiation Doses ◽

Diagnostic Reference Levels ◽

Reference Levels ◽

Dose Length Product ◽

Institutional Evaluation ◽

Starting Point ◽

First Results ◽

Ct Radiation ◽

Computed Tomography Dose Index

Abstract A pilot study has concerned the most frequent computed tomography examinations (CT). This represents the first results based on actual survey for diagnostic reference levels (DRLs) establishment in Algeria. A total number of 2540 patients underwent this survey that has included the recording of CT parameters, computed tomography dose index (CTDIvol) and dose-length product of the head, thorax, abdomen, abdomen–pelvis (AP), lumbar spine (LS) and thorax–abdomen–pelvis (TAP) performed on standard patients. The proposed DRLs are 71 mGy/1282 mGy.cm for head, 16 mGy/555 mGy.cm for thorax, 18 mGy/671 mGy.cm for abdomen, 21 mGy/950 mGy.cm for AP, 36 mGy/957 mGy.cm for LS and 18 mGy/994 mGy.cm for TAP. The rounded 75th percentile seems to be higher in some examinations compared to the literature. Our findings confirm the need to optimise our practice. These results provide a starting point for institutional evaluation of CT radiation doses.

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Application of a newly developed software program for image quality assessment in cone-beam computed tomography

Imaging Science in Dentistry ◽

10.5624/isd.2017.47.2.75 ◽

2017 ◽

Vol 47 (2) ◽

pp. 75 ◽

Cited By ~ 4

Author(s):

Marcus Vinicius Linhares de Oliveira ◽

António Carvalho Santos ◽

Graciano Paulo ◽

Paulo Sergio Flores Campos ◽

Joana Santos

Keyword(s):

Computed Tomography ◽

Image Quality ◽

Quality Assessment ◽

Cone Beam Computed Tomography ◽

Image Quality Assessment ◽

Cone Beam ◽

Software Program

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Dosimetric and image quality assessment of different acquisition protocols of a novel 64-slice CT scanner

10.1117/12.650618 ◽

2006 ◽

Author(s):

Cristina Vite ◽

Monica Mangini ◽

Sabina Strocchi ◽

Raffaele Novario ◽

Fabio Tanzi ◽

...

Keyword(s):

Image Quality ◽

Quality Assessment ◽

Image Quality Assessment ◽

Ct Scanner

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Commissioning a new CT simulator II: virtual simulation software

Journal of Radiotherapy in Practice ◽

10.1017/s1460396907006085 ◽

2007 ◽

Vol 6 (03) ◽

pp. 163-171

Author(s):

D. Kearns ◽

M. McJury

Keyword(s):

Computed Tomography ◽

Image Quality ◽

Image Registration ◽

System Performance ◽

Simulation Software ◽

Virtual Simulation ◽

3D Image ◽

Ct Scanner ◽

Treatment Unit ◽

Beam Parameters

AbstractThis paper continues the discussion on the commissioning tests performed on a new GE Lightspeed RT wide-bore computed tomography (CT) scanner, focusing on the GE Advantage Sim software (version 6.0).The tests performed and phantoms used to assess the virtual simulator functionality, including the 3D image display, contouring, treatment unit beam parameters, digitally reconstructed radiograph generation and image quality, isocentre generation and multi-modality image registration, are described.The series of tests performed showed the virtual simulation software to be working within acceptance tolerances suggested in the literature and baseline data have been obtained against which future comparisons of system performance have been made. Where no tolerances were available, we have suggested suitable values.

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