scholarly journals Evaluation of Impact of Factors Affecting CT Radiation Dose for Optimizing Patient Dose Levels

Diagnostics ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 787
Author(s):  
Ching-Ching Yang
Keyword(s):  
Multivariate Analysis ◽  
Patient Dose ◽  
Ct Scans ◽  
Coefficient Of Determination ◽  
Factors Affecting ◽  
Ct Dose ◽  
Dose Metrics ◽  
Ct Radiation ◽  
Ct Dose Index ◽  
Dose Levels

The dose metrics and factors influencing radiation exposure for patients undergoing head, chest, and abdominal computed tomography (CT) scans were investigated for optimization of patient dose levels. The local diagnostic reference levels (DRLs) of adult CT scans performed in our hospital were established based on 28,147 consecutive examinations, including 5510 head scans, 9091 chest scans, and 13,526 abdominal scans. Among the six CT scanners used in our hospital, four of them are 64-slice multi-detector CT units (MDCT64), and the other two have detector slices higher than 64 (MDCTH). Multivariate analysis was conducted to evaluate the effects of body size, kVp, mAs, and pitch on volume CT dose index (CTDIvol). The local DRLs expressed in terms of the 75th percentile of CTDIvol for the head, chest, and abdominal scans performed on MDCT64 were 59.32, 9.24, and 10.64 mGy, respectively. The corresponding results for MDCTH were 57.90, 7.67, and 9.86 mGy. In regard to multivariate analysis, CTDIvol showed various dependence on the predictors investigated in this study. All regression relationships have coefficient of determination (R2) larger than 0.75, indicating a good fit to the data. Overall, the research results obtained through our workflow could facilitate the modification of CT imaging procedures once the local DRLs are unusually high compared to the national DRLs.

scholarly journals Establishment of diagnostic reference levels arising from common CT examinations in Semnan County, Iran

2019 ◽  
Vol 25 (1) ◽  
pp. 51-55 ◽  
Author(s):  
Daryoush Khoramian ◽  
Soroush Sistani ◽  
Peyman Hejazi
Keyword(s):  
Cervical Spine ◽  
The Other ◽  
Reference Level ◽  
Ct Scanner ◽  
Dose Length Product ◽  
Ct Dose ◽  
Patient Doses ◽  
Ct Dose Index ◽  
Ct Scanners ◽  
Dose Levels

Abstract Objective: The literature has approved that the use of the concept of diagnostic reference level (DRL) as a part of an optimization process could help to reduce patient doses in diagnostic radiology comprising the Computed Tomography (CT) examinations. There are four public/governmental CT centers in the province (Semnan, Iran) and, to our knowledge, after about 12 years since the launch of the first CT scanner in the province there is no dosimetry information on those CT scanners. The aim of this study was to evaluate CT dose indices with the aim of the establishment of the DRL for head, chest, cervical spine, and abdomen-pelvis examinations. Methods: Scan parameters of 381 patients were collected during two months from 4 CT scanners. The CT dose index (CTDI) was measured using a calibrated ionization chamber on two cylindrical poly methyl methacrylate (PMMA) phantoms. For each sequences, weighted CTDI (CTDIw), volumetric CTDI (CTDIv) and dose length product (DLP) were calculated. The 75th percentile was proposed as the criterion for DRL values. Results: Proposed DRL (CTDIw, CTDIv, DLP) for the head, chest, cervical spine, and abdomen-pelvis were (46.1 mGy, 46.1 mGy, 723 mGy × cm), (13.8 mGy, 12.0 mGy, 377 mGy × cm), (40.0 mGy, 40.0 mGy, 572 mGy × cm) and (14.9 mGy, 12.1 mGy, 524 mGy × cm), respectively. Conclusion: Comparison with the others results from the other countries indicates that the head, chest and abdomen-pelvis scans in our region are lower or in the range of the other studies investigated in terms of dose. In the case of cervical spine scanning it’s necessary to review and regulate scan protocols to reach acceptable dose levels.

scholarly journals Doses from cervical spine computed tomography (CT) examinations in the UK

2018 ◽  
Vol 91 (1085) ◽  
pp. 20170834 ◽  
Author(s):  
John R Holroyd ◽  
Sue Edyvean
Keyword(s):  
Cervical Spine ◽  
Mean Value ◽  
Patient Dose ◽  
Diagnostic Reference Levels ◽  
Reference Levels ◽  
Ct Dose ◽  
Spine Ct ◽  
Ct Dose Index ◽  
The Uk ◽  
Dose Index

Objective: To review doses to patients undergoing cervical spine CT examinations in the UK. Methods: A data collection form was developed and distributed to medical physicists and radiographers via e-mail distribution lists. The form requested details of CT scanners, exposure protocols and patient dose index information. Results: Data were received for 73 scanners. It was seen that 97% of scanners used automatic exposure control, and 60% of scanners used an iterative reconstruction technique for cervical spine examinations. The majority of scans were taken at 120 kV. The average patient dose indicators in terms of CT dose index (CTDIvol) ranged from 3.5 to 39.7 mGy (mean value 16.7 mGy), and for the DLP, ranged from 87 to 1030 mGy cm (mean value 379 mGy cm) as quoted for the standard 32 cm phantom. Conclusion: The rounded third quartile value of the mean dose distributions from this study were a CT dose index (CTDIvol) of 20 mGy and a dose–length product of 440 mGy cm as quoted for a 32 cm body phantom. These are significantly higher than those in the 2011 Public Health England CT dose survey when adjusted for phantom size. It is suggested that the existing national diagnostic reference levels for cervical spine CT should be amended, both with the new values and also to quote according to the 32 cm phantom. Advances in knowledge: Proposed new national diagnostic reference levels are presented for cervical spine CT examinations.

scholarly journals CT Dose Index and Patient Dose: They AreNotthe Same Thing

Radiology ◽  
2011 ◽  
Vol 259 (2) ◽  
pp. 311-316 ◽  
Author(s):  
Cynthia H. McCollough ◽  
Shuai Leng ◽  
Lifeng Yu ◽  
Dianna D. Cody ◽  
John M. Boone ◽  
...  
Keyword(s):  
Patient Dose ◽  
Ct Dose ◽  
Ct Dose Index ◽  
Dose Index

OPTIMIZATION OF RADIATION DOSE IN CT IMAGING: ESTABLISHING THE INSTITUTIONAL DIAGNOSTIC REFERENCE LEVELS AND PATIENT DOSE AUDITING

2019 ◽  
Vol 188 (2) ◽  
pp. 213-221 ◽  
Author(s):  
Mohd Amir Syahmi Mat Razali ◽  
Muhamad Zabidi Ahmad ◽  
Ibrahim Lutfi Shuaib ◽  
Noor Diyana Osman
Keyword(s):  
Dose Distribution ◽  
Population Characteristics ◽  
Contrast Study ◽  
Diagnostic Reference Levels ◽  
Reference Levels ◽  
Dose Length Product ◽  
Ct Dose ◽  
Dose Metrics ◽  
Ct Technology ◽  
Ct Dose Index

Abstract The aim of this study was to propose local diagnostic reference levels (LDRLs) for the most common computed tomography (CT) examinations (including contrast and non-contrast scan phase) performed at Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia (USM), Malaysia. A retrospective CT dose survey of 1488 subjects from January 2015 until December 2018 was performed at AMDI USM, Malaysia. The proposed DRLs were established at 50th and 75th percentile of dose distribution for all dose metrics (CT dose index [CTDI]; CTDIvol, CTDIw and dose–length product). The proposed LDRLs were compared with national DRLs and other established DRLs. The 10 most common CT examinations at AMDI were thorax–abdomen–pelvis (TAP) CT (46%), followed by pelvis CT (17%), abdomen–pelvis CT (10%), brain/head CT (9%) and other CT protocols. The local DRLs were established using the third quartile values of dose distribution and were categorized based on CT region protocols. Most of the proposed DRLs were exceeded the national DRLs (63%) and other international DRLs (67%). From the dose auditing, almost half of the recent dose data (for year 2018) exceeded the proposed local DRLs and the unusual dose were observed in TAP, brain/head and pelvis CT examinations. The unusual higher dose could be due to higher mAs settings, higher number of scan phase for contrast study and higher pitch factor. The local DRLs should be established for dose optimization and reduction of the occurrence of excessive radiation exposure to the patients. The establishment of the Ads and LDRLs should also consider all the factors that affect the variation in DRLs such as CT technology, scanning protocols and population characteristics. The local dose distribution should always be revised for improvement of the current local practice.

scholarly journals Revue Des Doses d’Exposition Et Des Methode d’Optimisation En Tomodensitometrie (TDM) De l’Enfant Au Togo

2016 ◽  
Vol 12 (6) ◽  
pp. 56
Author(s):  
M. Tchaou ◽  
G.N. Gnakadja ◽  
B. N’timon ◽  
L. Sonhaye ◽  
A. Amadou ◽  
...  
Keyword(s):  
Medical Training ◽  
Ct Scans ◽  
Age Group ◽  
French Society ◽  
Facial Bones ◽  
Dose Length Product ◽  
Ct Dose ◽  
Continue Medical ◽  
Female Children ◽  
Ct Dose Index

Objectives: To assess the justification of indications of CT scans and the exposure doses of children during CT scans. Methods: Prospective study of 104 CT-sans of children collected over a period of 6 months. Results: Female children were predominant with a sex ratio female / male of 1.2. The predominant age group was the 10 to 15 years (41%). The CT-Scan of the head was the most practiced exam, with 64.42% (67/104). When analyzing information according to the recommendations of the Guide of well practices of French Society of Radiology (SFR) and the French Society of Biophysics and Nuclear Medicine (SFBMN), only 77% of CT-Scans were justified. Almost half (49.04%) of CT-Scans had a CT-Dose Index (CTDI) and Dose Length Product (DLP) greater than the French reference norms defined for each group of age. The average values of CTDI and DLP are above the norms for all CT-scans of the skull, facial bones and sinuses. Conclusion: The doses administered to children by CT-Scans are above accepted norms. Improved practices continue medical training of radiology manipulators and the creation of a regulatory or an agency of radioprotection is necessary.

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 Multivariate analysis of various factors affecting background liver and mediastinal standardized uptake values

2012 ◽  
Vol 27 (1) ◽  
pp. 20 ◽  
Author(s):  
BhagwantRai Mittal ◽  
MohammedLabeeb Abrar ◽  
Anish Bhattacharya ◽  
Raghava Kashyap ◽  
Manohar Kuruva
Keyword(s):  
Multivariate Analysis ◽  
Factors Affecting ◽  
Standardized Uptake Values
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