scholarly journals Prediction of Organ and Effective dose with known mAs and kVp for Dose Optimisation Protocol and Recommendations in CT

2017 ◽  
pp. 216-222
Author(s):  
Issahaku Shirazu ◽  
Y. B. Mensah ◽  
Cyril Schandorf ◽  
S. Y. Mensah ◽  
Theophilus Sackey ◽  
...  
Keyword(s):  
Ct Scan ◽  
Effective Dose ◽  
Image Data ◽  
Organ Dose ◽  
Exposure Dose ◽  
Pitch Factor ◽  
Dose Length Product ◽  
Modeling Process ◽  
Clinical Recommendation ◽  
Dose Management

In medical exposure dose to patients are determine by input parameters including mAs, kVp, pitch factor among other factors. The aim of this study is to provide procedure and protocol of how to assess patients’ dose (organ and effective dose) estimates with preset eff mAs and standard kVp. This is to determine a tradeoff between patient’s dose and the image quality before imaging. In addition to providing appropriate clinical recommendation for clinicians for dose management during CT scan. MVL DICOM application software was used to access image data during abdominal CT scan. Organ and effective dose estimates were estimated as developed by ICRP 103 recommendations. Where on the image data, using MVL platform detail information of the mAs, kVp, CTDI<sup>vol</sup> and DLP were available for recording. <span style="background:white">The weighted CTDI (CTDI<sup>W</sup>) was estimated by multiplying the volume CTDI (CTDI<sup>VOL</sup>) by the pitch factor. Which was used to estimate organ dose using </span>the normalized organ dose factor <span style="background:white">and the effective dose was estimated by</span> the product of the region-specific normalizing constant and the dose length product.<span style="background:white"> The </span>mAs is the effective Milliameter per second, which were calculated by dividing the mAs by the pitch factor. The relationship between input and output parameters were modeled as the final component of the modeling process in a form of GUI applications format. This was done to establish the various process and procedures involve in abdominal scan for dose managements. The coding process involve the use of written visual basic code to design an interface and integrated on the MVL application platform for clinical application. The GUI has been recommended for use by various stake holders in CT operations.

scholarly journals Estimation of Exposure Dose on MDCT Examination -The Measurement of Organ Dose and Effective Dose by Anthropomorphic Phantom-

2010 ◽  
Vol 66 (8) ◽  
pp. 901-910 ◽  
Author(s):  
Takumi Hirata ◽  
Kenji Inoue ◽  
Shinji Shigemori ◽  
Michitaka Matsuzaki, ◽  
Kouji Inatomi
Keyword(s):  
Effective Dose ◽  
Organ Dose ◽  
Exposure Dose ◽  
Anthropomorphic Phantom ◽  
Mdct Examination

Analisis Reduksi Dosis Efektif Mata Pada Fantom Menggunakan TLD Mata dengan Implementasi Software Organ Dose Modulation (ODM) dan Eyeshield pada Protokol CT Kepala dengan Alat GE Revolution Evo 128 Slice

2021 ◽  
Vol 1 (1) ◽  
pp. 26-30
Author(s):  
Dito Andi Rukmana ◽  
◽  
Veronika Saron Kamantuh ◽  
Bambang Dwinanto ◽  
Lutfiana Desy Saputri
Keyword(s):  
Image Quality ◽  
Ct Scan ◽  
Effective Dose ◽  
Research Method ◽  
Dose Calculation ◽  
Organ Dose ◽  
Head Ct ◽  
Affect Image Quality ◽  
Dose Modulation

The eye is one of the sensitive organs that need attention in the head CT-Scan. This study aims to reduce the effective eye dose on a head CT-Scan using ODM (Organ Dose Modulation) software and use eyeshield on the phantom. The study was conducted using a CT-Scan tool GE Revolution Evo 128 Slice. The research method was carried out by placing three pairs of eye TLDs (Hp3 Dosimeters) on the phantom for the three examination configurations, CT-Scan standard (routine) examinations, examinations using ODM software, and examinations using ODM software and eyeshield. The estimated effective dose calculation based on TLD reading for the eye lens on a standard CT-Scan (routine) is 1.29 mSv. Examination with ODM software is 1.03 mSv. Examination with ODM software and eyeshield of 0.9 mSv. Based on the results obtained, a head CT-Scan with ODM software can reduce the dose by 20% from a routine head CT-Scan, and if added with an eyeshield, it can reduce the dose by 30%. The quality of the image produced by implementing ODM software, SNR value decreased from 39 to 35 in the anterior phantom, central and posterior parts remained. However, the change in SNR value is not significant, so it does not change the image quality. Furthermore, the addition of eyeshield does not alter the SNR value, which means that the addition eyeshield does not cause artifacts that affect image quality. Using ODM and eyeshield software is indeed a little more complicated than a routine head CT-Scan. Still, the benefits obtained are pretty significant, reducing the effective dose received by the eye without reducing image quality.

scholarly journals Estimation of effective dose from CT scanning using dose length product in a Nepalese hospital

2020 ◽  
Vol 6 (1) ◽  
pp. 56-63
Author(s):  
Pooja Shah
Keyword(s):  
Ct Scan ◽  
Effective Dose ◽  
Ct Scanning ◽  
Reference Level ◽  
Radiation Doses ◽  
Reference Levels ◽  
Contrast Imaging ◽  
Dose Length Product ◽  
Effective Doses ◽  
The Mean

Keywords: Effective dose, Dose Length Product, Computed Tomography Dose Indexvolume, Dose Reference Level AbstractAim: The aim of this study was to estimate the effective doses from CT scans using DoseLength Product (DLP) in a Nepalese hospital.Materials and methods: This prospective study was conducted in 150 patients above 18years of age who were referred for CT scan of head, chest and abdomen. The CT scan wasperformed on a 128 slice multi detector scanner. All the subjects who met the inclusioncriteria were included in the study. Following the non-contrast imaging phases of the head,chest and abdomen CTDIvol, DLP, kVp and pitch were recorded for each patient from theconsole display of the scanner. The effective dose was calculated for each examination usingDLP which were graphically analyzed and correlated with the age of the patient.Results: The study showed the mean CTDIvol for head, chest and abdomen to be 53.95±4.83mGy, 5.28±1.17 mGy and 11.15±2.71 mGy respectively along with mean DLP to be923.52±71.11 mGycm, 229.32±48.70 mGycm and 517.02±148.32 mGycm respectively. Usingthese values, the mean effective doses were calculated and found to be 1.93±0.14 mSv,3.20±0.68 mSv and 7.75±2.19 mSv respectively.Conclusion: The calculated effective dose values were lower than in other studies for CTexaminations of chest and abdomen while higher or similar for CT examination of head. Theresults of this survey could motivate other researchers to investigate the radiation doses inother hospitals and help establish national diagnostic reference levels.  

scholarly journals Measurements of CTDI and DLP from CT image data for paediatrics radiological performance evaluation and dose optimisation in Ghana

2018 ◽  
pp. 162-166
Author(s):  
I. Shirazu ◽  
T. A Sackey ◽  
E K Eduful ◽  
T B. Dery ◽  
M. Pokoo-Aikins ◽  
...  
Keyword(s):  
Image Quality ◽  
Medical Imaging ◽  
Radiation Dose ◽  
Ct Scan ◽  
Effective Dose ◽  
Image Data ◽  
Imaging Parameters ◽  
Dose Optimisation ◽  
Paediatric Imaging ◽  
Effects Of Radiation

Risk of developing cancer in paediatric patients is higher compared with adults and hence need for optimization strategies in paediatric medical imaging is very critical. The higher risk is attributable to the fact that children have developing organs and tissues which are more sensitive to the effects of radiation, and also they have longer life expectancy which allows more time for any harmful effects of radiation to manifest. Optimization of radiological protection is a means of adjusting imaging parameters and instituting protective measures such that required images are obtained with lowest possible radiation dose, and net benefit is maximized to maintain sufficient image quality for diagnostic purposes. Special consideration is given to the availability of dose reduction measures for paediatric imaging equipment. A unique aspect of paediatric imaging is with regards to the wide range in patient sizes and weights, therefore requiring special attention to optimization and modification of equipment, technique, and imaging parameters. Good radiographic technique for paediatrics include attention to patient positioning, field size and adequate collimation, use of protective shielding, optimization of exposure factors etc. In CT, dose reduction is optimized by the adjustment of scan parameters such as mA, kVp, and pitch in accordance with patient weight, age, region scanned, and study indication. Paediatric radiological imaging should therefore be performed by trained and experienced health personnel in the medical imaging department. The overall aim of the research was to enhance the capability of Ghana to improve the efficiency of existing modalities for paediatric medical imaging and to implement and enhance optimization techniques and methodologies for advanced paediatric medical imaging in CT. In addition to providing appropriate clinical recommendation for clinicians for dose management during CT scan. MVL DICOM application software was used to access image data during abdominal CT scan. Effective dose estimates were estimated as developed by ICRP 103 recommendations. The data collection was based on retrospective extraction of image data, using MVL platform where detailed information of the CTDIvol and DLP were available for recording. The weighted CTDI (CTDIW) was estimated by multiplying the volumetric CTDI (CTDIVOL) by the pitch factor. The effective dose was estimated by the product of the region-specific normalizing constant and the dose length product on each image. For image quality Signal to Noise Ratio was estimated and compare with effective dose for dose optimisation. In conclusion, the mean dose parameters exceeded the recommended dose parameter and hence an urgent need for an action to minimise radiation dose to paediatric patients.

scholarly journals Whole Body Low Dose Computed Tomography Using Third-Generation Dual-Source Multidetector With Spectral Shaping: Protocol Optimization and Literature Review

Dose-Response ◽  
2020 ◽  
Vol 18 (4) ◽  
pp. 155932582097313
Author(s):  
Dario Baldi ◽  
Liberatore Tramontano ◽  
Vincenzo Alfano ◽  
Bruna Punzo ◽  
Carlo Cavaliere ◽  
...  
Keyword(s):  
Effective Dose ◽  
Low Dose ◽  
Whole Body ◽  
Dose Length Product ◽  
Osteolytic Lesions ◽  
Subjective Image Quality ◽  
Ct Dose ◽  
Dual Source ◽  
Ct Dose Index ◽  
Low Dose Computed Tomography

For decades, the main imaging tool for multiple myeloma (MM) patient’s management has been the conventional skeleton survey. In 2014 international myeloma working group defined the advantages of the whole-body low dose computed tomography (WBLDCT) as a gold standard, among imaging modalities, for bone disease assessment and subsequently implemented this technique in the MM diagnostic workflow. The aim of this study is to investigate, in a group of 30 patients with a new diagnosis of MM, the radiation dose (CT dose index, dose-length product, effective dose), the subjective image quality score and osseous/extra-osseous findings rate with a modified WBLDCT protocol. Spectral shaping and third-generation dual-source multidetector CT scanner was used for the assessment of osteolytic lesions due to MM, and the dose exposure was compared with the literature findings reported until 2020. Mean radiation dose parameters were reported as follows: CT dose index 0.3 ± 0.1 mGy, Dose-Length Product 52.0 ± 22.5 mGy*cm, effective dose 0.44 ± 0.19 mSv. Subjective image quality was good/excellent in all subjects. 11/30 patients showed osteolytic lesions, with a percentage of extra-osseous findings detected in 9/30 patients. Our data confirmed the advantages of WBLDCT in the diagnosis of patients with MM, reporting an effective dose for our protocol as the lowest among previous literature findings.

scholarly journals Converting Dose-Length Product to Effective Dose at CT

Radiology ◽  
2008 ◽  
Vol 248 (3) ◽  
pp. 995-1003 ◽  
Author(s):  
Walter Huda ◽  
Kent M. Ogden ◽  
Mohammad R. Khorasani
Keyword(s):  
Effective Dose ◽  
Dose Length Product

Electrical, Diffusional, and Hydraulic Tortuosity Anisotropy Quantification Using 3D CT-Scan Image Data

2021 ◽  
Author(s):  
Andres Gonzalez ◽  
Zoya Heidari ◽  
Olivier Lopez
Keyword(s):  
Porous Media ◽  
Fluid Flow ◽  
Ct Scan ◽  
Numerical Simulations ◽  
Potential Distribution ◽  
Image Data ◽  
Gas Diffusion ◽  
Depth Interval ◽  
Micro Ct ◽  
Multi Scale

Abstract Depositional mechanisms of sediments and post-depositional process often cause spatial variation and heterogeneity in rock fabric, which can impact the directional dependency of petrophysical, electrical, and mechanical properties. Quantification of the directional dependency of the aforementioned properties is fundamental for the appropriate characterization of hydrocarbon-bearing reservoirs. Anisotropy quantification can be accomplished through numerical simulations of physical phenomena such as fluid flow, gas diffusion, and electric current conduction in porous media using multi-scale image data. Typically, the outcome of these simulations is a transport property (e.g., permeability). However, it is also possible to quantify the tortuosity of the media used as simulation domain, which is a fundamental descriptor of the microstructure of the rock. The objectives of this paper are (a) to quantify tortuosity anisotropy of porous media using multi-scale image data (i.e., whole-core CT-scan and micro-CT-scan image stacks) through simulation of electrical potential distribution, diffusion, and fluid flow, and (b) to compare electrical, diffusional, and hydraulic tortuosity. First, we pre-process the images (i.e., CT-scan images) to remove non-rock material visual elements (e.g., core barrel). Then, we perform image analysis to identify different phases in the raw images. Then, we proceed with the numerical simulations of electric potential distribution. The simulation results are utilized as inputs for a streamline algorithm and subsequent direction-dependent electrical tortuosity estimation. Next, we conduct numerical simulation of diffusion using a random walk algorithm. The distance covered by each walker in each cartesian direction is used to compute the direction-dependent diffusional tortuosity. Finally, we conduct fluid-flow simulations to obtain the velocity distribution and compute the direction-dependent hydraulic tortuosity. The simulations are conducted in the most continuous phase of the segmented whole-core CT-scan image stacks and in the segmented pore-space of the micro-CT-scan image stacks. Finally, the direction-dependent tortuosity values obtained with each technique are employed to assess the anisotropy of the evaluated samples. We tested the introduced workflow on dual energy whole-core CT-scan images and on smaller scale micro-CT-scan images. The whole-core CT-scan images were obtained from a siliciclastic depth interval, composed mainly by spiculites. Micro-CT-scan images we obtained from Berea Sandstone and Austin Chalk formations. We observed numerical differences in the estimates of direction-dependent electrical, diffusional, and hydraulic tortuosity for both types of image data employed. The highest numerical differences were observed when comparing electrical and hydraulic tortuosity with diffusional tortuosity. The observed differences were significant specially in anisotropic samples. The documented comparison provides useful insight in the selection process of techniques for estimation of tortuosity. The use of core-scale image data in the proposed workflow provides semi-continuous estimates of tortuosity and tortuosity anisotropy which is typically not attainable when using pore-scale images. Additionally, the semi-continuous nature of the tortuosity and tortuosity anisotropy estimates in whole-core CT-scan image data provides an excellent tool for the selection of core plugs coring locations.

scholarly journals Lung cancer classification using fuzzy c-means and fuzzy kernel C-Means based on CT scan image

2021 ◽  
Vol 10 (2) ◽  
pp. 291
Author(s):  
Zuherman Rustam ◽  
Aldi Purwanto ◽  
Sri Hartini ◽  
Glori Stephani Saragih
Keyword(s):  
Lung Cancer ◽  
Ct Scan ◽  
Lung Nodule ◽  
Image Data ◽  
Cluster Center ◽  
Support Vector ◽  
Fuzzy C Means ◽  
Kernel Distance ◽  
Abnormal Cells ◽  
Membership Matrix

<span id="docs-internal-guid-94842888-7fff-2ae1-cd5c-026943b95b7f"><span>Cancer is one of the diseases with the highest mortality rate in the world. Cancer is a disease when abnormal cells grow out of control that can attack the body's organs side by side or spread to other organs. Lung cancer is a condition when malignant cells form in the lungs. To diagnose lung cancer can be done by taking x-ray images, CT scans, and lung tissue biopsy. In this modern era, technology is expected to help research in the field of health. Therefore, in this study feature extraction from CT images was used as data to classify lung cancer. We used CT scan image data from SPIE-AAPM Lung CT challenge 2015. Fuzzy C-Means and fuzzy kernel C-Means were used to classify the lung nodule from the patient into benign or malignant. Fuzzy C-Means is a soft clustering method that uses Euclidean distance to calculate the cluster center and membership matrix. Whereas fuzzy kernel C-Means uses kernel distance to calculate it. In addition, the support vector machine was used in another study to obtain 72% average AUC. Simulations were performed using different k-folds. The score showed fuzzy kernel C-Means had the highest accuracy of 74%, while fuzzy C-Means obtained 73% accuracy. </span></span>

Sign in / Sign up

Export Citation Format

Share Document