Changing Radiation Dose from Diagnostic Computed Tomography Examinations in Saskatchewan

2012 ◽  
Vol 63 (3) ◽  
pp. 183-191 ◽  
Author(s):  
Chance S. Dumaine ◽  
David A. Leswick ◽  
Derek A. Fladeland ◽  
Hyun J. Lim ◽  
Lori J. Toews
Keyword(s):  
Radiation Dose ◽  
Single Phase ◽  
Body Parts ◽  
Effective Radiation Dose ◽  
Dose Length Product ◽  
Variation Reduction ◽  
Ct Head ◽  
The Mean ◽  
Effective Radiation

Purpose Follow-up study to observe if provincial mean effective radiation dose for head, chest, and abdomen-pelvis (AP) computed tomographies (CTs) remained stable or changed since the initial 2006 survey. Methods Data were collected in July 2008 from Saskatchewan's 13 diagnostic CT scanners of 3358 CT examinations. These data included the number of scan phases and projected dose length product (DLP). Technologists compared projected DLP with 2006 reference data before scanning. Projected DLP was converted to effective dose (ED) for each head, chest, and AP CT. The total dose that the patients received with scans of multiple body parts at the same visit also was determined. Results The mean (± SD) provincial ED was 3.4 ± 1.6 mSv for 1023 head scans (2.7 ± 1.6 mSv in 2006), 9.6 ± 4.8 mSv for 588 chest scans (11.3 ± 8.9 mSv in 2006), and 16.1 ± 9.9 mSv for 983 AP scans (15.5 ± 10.0 mSv in 2006). Single-phase multidetector row CT ED decreased by 31% for chest scans (9.5 ± 3.9 mSv vs 13.7 ± 9.7 mSv in 2006) and 17% for AP scans (13.9 ± 6.0 mSv vs 16.8 ± 10.6 mSv in 2006) and increased by 19% for head scans (3.2 ± 1.2 mSv vs 2.7 ± 1.5 mSv in 2006). The total patient dose was highest (33.8 ± 10.1 mSv) for the 20 patients who received head, neck, chest, and AP scans during a single visit. Because of increased utilisation and the increased CT head dose, Saskatchewan per capital radiation dose from CT increased by 21% between 2006 and 2008 (1.14 vs 1.38 mSv/person per year). Conclusion Significant dose and variation reduction was seen for single-phase CT chest and AP examinations between 2006 and 2008, whereas CT head dose increased over the same interval. These changes, combined with increased utilisation, resulted in per capita increase in radiation dose from CT between the 2 studies.

scholarly journals Reducing cranial computed tomography effective radiation dose by 30% using adaptive iterative dose reduction

2016 ◽  
Vol 25 (4) ◽  
pp. 230-234
Author(s):  
Wai-Yung Yu ◽  
Thye Sin Ho ◽  
Henry Ko ◽  
Wai-Yee Chan ◽  
Serene Ong ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Radiation Dose ◽  
Dose Reduction ◽  
Diagnostic Image Quality ◽  
Radiation Doses ◽  
Effective Radiation Dose ◽  
Diagnostic Image ◽  
Ct Head ◽  
Effective Radiation

Introduction: The use of computed tomography (CT) imaging as a diagnostic modality is increasing rapidly and CT is the dominant contributor to diagnostic medical radiation exposure. The aim of this project was to reduce the effective radiation dose to patients undergoing cranial CT examination, while maintaining diagnostic image quality. Methods: Data from a total of 1003, 132 and 27 patients were examined for three protocols: CT head, CT angiography (CTA), and CT perfusion (CTP), respectively. Following installation of adaptive iterative dose reduction (AIDR) 3D software, tube current was lowered in consecutive cycles, in a stepwise manner and effective radiation doses measured at each step. Results: Baseline effective radiation doses for CT head, CTA and CTP were 1.80, 3.60 and 3.96 mSv, at currents of 300, 280 and 130–150 mA, respectively. Using AIDR 3D and final reduced currents of 160, 190 and 70–100 mA for CT head, CTA and CTP gave effective doses of 1.29, 3.18 and 2.76 mSv, respectively. Conclusion: We demonstrated that satisfactory reductions in the effective radiation dose for CT head (28.3%), CTA (11.6%) and CTP (30.1%) can be achieved without sacrificing diagnostic image quality. We have also shown that iterative reconstruction techniques such as AIDR 3D can be effectively used to help reduce effective radiation dose. The dose reductions were performed within a short period and can be easily achievable, even in busy departments.

Radiation doses in diagnostic imaging for suspected physical abuse

2019 ◽  
Vol 104 (9) ◽  
pp. 863-868 ◽  
Author(s):  
Raylene Rao ◽  
Diana Browne ◽  
Brian Lunt ◽  
David Perry ◽  
Peter Reed ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Effective Dose ◽  
Physical Abuse ◽  
Background Radiation ◽  
Imaging Techniques ◽  
Bone Imaging ◽  
Effective Radiation Dose ◽  
Ct Head ◽  
Contrast Ct ◽  
Effective Radiation

ObjectiveTo measure the actual radiation dose delivered by imaging techniques commonly used in the radiography of suspected physical abuse and to make this information available to health professionals and families.MethodsData were collected retrospectively on children under 3 years referred for skeletal surveys for suspected physical abuse, non-contrast CT head scan or radionuclide imaging of the bones in Starship Children’s Hospital, Auckland, New Zealand from January to December 2015. Patient size-specific conversion coefficients were derived from International Commission on Radiologic Protection tissue weighting factors and used to calculate effective dose.ResultsSeventy-one patients underwent an initial skeletal survey, receiving a mean effective dose of 0.20 mSv (95% CI 0.18 to 0.22). Sixteen patients had a follow-up survey with a mean effective dose of 0.10 mSv (95% CI 0.08 to 0.11). Eighty patients underwent CT head which delivered a mean effective dose of 2.49 mSv (95% CI 2.37 to 2.60). Thirty-nine patients underwent radionuclide bone imaging which delivered a mean effective dose of 2.27 mSv (95% CI 2.11 to 2.43).ConclusionsIn a paediatric centre, skeletal surveys deliver a relatively low effective radiation dose, equivalent to approximately 1 month of background radiation. Non-contrast CT head scan and radionuclide bone imaging deliver similar doses, equivalent to approximately 1 year of background radiation. This information should be considered when gaining informed consent and incorporated in patient education handouts.

Combined evaluation of myocardial perfusion and coronary morphology in the identification of subclinical CAD

2010 ◽  
Vol 49 (05) ◽  
pp. 173-182 ◽  
Author(s):  
G. Vincenti ◽  
A. Quercioli ◽  
H. Zaidi ◽  
R. Nkoulou ◽  
S. Dewarrat ◽  
...  
Keyword(s):  
Cardiovascular Risk ◽  
Radiation Dose ◽  
Myocardial Perfusion ◽  
Ct Perfusion ◽  
Healthy Controls ◽  
Effective Radiation Dose ◽  
Pet Ct ◽  
The Mean ◽  
Effective Radiation ◽  
Ecg Pulsing

Summary Purpose: To evaluate the mean effective radiation dose of 13N-ammonia PET/CT and ECGpulsing CT angiography (CTA) in the evaluation of myocardial perfusion, myocardial blood flow (MBF) and coronary morphology for the identification of subclinical CAD. Patients, material, methods: Following rest-stress 13N-ammonia PET/CT perfusion imaging and MBF quantification, ECG-pulsing CTA at a pulse window of 70% of the R-R cycle was performed in ten healthy controls and in sixteen individuals with cardiovascular risk factors. Individual radiation dose exposure for ECG-pulsing CTA was estimated from the dose-length product. Results: PET demonstrated normal perfusion in all study individuals, while hyperemic MBFs during dipyridamole stimulation and the myocardial flow reserve (MFR) in cardiovascular risk individuals were significantly lower than in healthy controls (1.34 ± 0.26 vs. 2.28 ± 0.47 ml/g/min and 1.48 ± 0.39 vs. 3.24 ± 0.81, both p . 0.0001). Further, ECG-pulsing CTA identified mild calcified and non-calcified coronary plaque burden in 7 (43%) individuals of the cardiovascular risk group. Rest-stress 13N-ammonia PET/CT perfusion study yielded a mean effective radiation dose of 3.07 ± 0.06 mSv (2.07 ± 0.06 mSv from the rest-stress 13N-ammonia injections and 1.0 mSv from the 2 CT transmission scans), while ECG-pulsing CTA was associated with 5.57 ± 2.00 mSv. The mean effective radiation dose of the combined 13N-ammonia PET/CT and ECG-pulsing CTA exams in the evaluation of myocardial perfusion and coronary morphology was 8.0 ± 1.5 mSv. Conclusion: 13N-ammonia PET/CT and ECG-pulsing CTA affords cardiac hybrid imaging studies in the evaluation of subclinical CAD with a relatively low mean effective radiation exposure of 8.0 ± 1.5mSv.

Effective Radiation Dose in a Skeletal Survey Performed for Suspected Child Abuse

2016 ◽  
Vol 171 ◽  
pp. 310-312 ◽  
Author(s):  
Rachel P. Berger ◽  
Ashok Panigrahy ◽  
Shawn Gottschalk ◽  
Michael Sheetz
Keyword(s):  
Child Abuse ◽  
Radiation Dose ◽  
Skeletal Survey ◽  
Effective Radiation Dose ◽  
Effective Radiation

scholarly journals Simulated Radiation Dose Reduction in Whole-Body CT on a 3rd Generation Dual-Source Scanner: An Intraindividual Comparison

Diagnostics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 118
Author(s):  
Andreas S. Brendlin ◽  
Moritz T. Winkelmann ◽  
Phuong Linh Do ◽  
Vincent Schwarze ◽  
Felix Peisen ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Dose Reduction ◽  
Whole Body ◽  
Reference Standard ◽  
Diagnostic Confidence ◽  
Effective Radiation Dose ◽  
Intraindividual Comparison ◽  
Dual Source ◽  
Effective Radiation

To evaluate the effect of radiation dose reduction on image quality and diagnostic confidence in contrast-enhanced whole-body computed tomography (WBCT) staging. We randomly selected March 2016 for retrospective inclusion of 18 consecutive patients (14 female, 60 ± 15 years) with clinically indicated WBCT staging on the same 3rd generation dual-source CT. Using low-dose simulations, we created data sets with 100, 80, 60, 40, and 20% of the original radiation dose. Each set was reconstructed using filtered back projection (FBP) and Advanced Modeled Iterative Reconstruction (ADMIRE®, Siemens Healthineers, Forchheim, Germany) strength 1–5, resulting in 540 datasets total. ADMIRE 2 was the reference standard for intraindividual comparison. The effective radiation dose was calculated using commercially available software. For comparison of objective image quality, noise assessments of subcutaneous adipose tissue regions were performed automatically using the software. Three radiologists blinded to the study evaluated image quality and diagnostic confidence independently on an equidistant 5-point Likert scale (1 = poor to 5 = excellent). At 100%, the effective radiation dose in our population was 13.3 ± 9.1 mSv. At 20% radiation dose, it was possible to obtain comparably low noise levels when using ADMIRE 5 (p = 1.000, r = 0.29). We identified ADMIRE 3 at 40% radiation dose (5.3 ± 3.6 mSv) as the lowest achievable radiation dose with image quality and diagnostic confidence equal to our reference standard (p = 1.000, r > 0.4). The inter-rater agreement for this result was almost perfect (ICC ≥ 0.958, 95% CI 0.909–0.983). On a 3rd generation scanner, it is feasible to maintain good subjective image quality, diagnostic confidence, and image noise in single-energy WBCT staging at dose levels as low as 40% of the original dose (5.3 ± 3.6 mSv), when using ADMIRE 3.

scholarly journals Effective ?-radiation Dose on Chitosan for Preservation of Mangoes (Mangifera indica)

2013 ◽  
Vol 2 ◽  
pp. 35-40 ◽  
Author(s):  
Ashna Islam ◽  
Mahfuza Sharifa Sultana ◽  
Fahmida Parvin ◽  
Mubarak A Khan
Keyword(s):  
Weight Loss ◽  
Radiation Dose ◽  
Shelf Life ◽  
Effective Dose ◽  
Room Temperature ◽  
Color Change ◽  
Mangifera Indica ◽  
Chitosan Solution ◽  
Effective Radiation Dose ◽  
Effective Radiation

The effective dose of ? radiation on chitosan for mango preservation was studies in this work. The 2% chitosan solution was irradiated with at various total doses (50-200 kGy). The mature green mangoes were soaked in un-irradiated and irradiated chitosan solutions and then they were stored at normal room temperature. The percentage of weight loss, color change and percentage of spoilage were observed for 15 days in control, un-irradiated and irradiated chitosan coated mangoes. The overall results showed the superiority of 50 kGy and 100 kGy irradiated chitosan in extending shelf life of mango as comared to control, un-irradiated and 120 kGy to 200 kGy irradiated chitosan. Jahangirnagar University Environmental Bulletin, Vol.2, 35-40, 2013 DOI: http://dx.doi.org/10.3329/jueb.v2i0.16328

Estimating Radiation Dose to Major Organs in Dental X-Ray Examinations: A Phantom Study

2020 ◽  
Author(s):  
Yong Li ◽  
Bingsheng Huang ◽  
Jun Cao ◽  
Tianqi Fang ◽  
Guoqing Liu ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Reference Level ◽  
Radiation Doses ◽  
Diagnostic Reference Level ◽  
Effective Radiation Dose ◽  
Organ Doses ◽  
X Ray ◽  
Absorbed Doses ◽  
Males And Females ◽  
Effective Radiation

Abstract The radiation doses absorbed by major organs of males and females were studied from three types of dental X-ray devices. The absorbed doses from cone-beam computed tomography (CBCT), panoramic and intraoral X-ray machines were in the range of 0.23–1314.85 μGy, and were observed to be high in organs and tissues located in or adjacent to the irradiated area, there were discrepancies in organ doses between male and female. Thyroid, salivary gland, eye lens and brain were the organs that received higher absorbed doses. The organ absorbed doses were considerably lower than the diagnostic reference level for dental radiography in China. The calculated effective radiation doses for males and females were 56.63, 8.15, 2.56 μSv and 55.18, 8.99, 2.39 μSv, respectively, when using CBCT, the panoramic X-ray machine and intraoral X-ray machine. The effective radiation dose caused by CBCT was much higher than those of panoramic and intraoral X-ray machines.

scholarly journals The feasibility of low-concentration contrast and low tube voltage in computed tomography perfusion imaging: an animal study

2018 ◽  
Vol 38 (1) ◽  
Author(s):  
Yuning Pan ◽  
Aiqin Song ◽  
Shizhong Bu ◽  
Zhaoqian Chen ◽  
Qiuli Huang ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Perfusion Imaging ◽  
Ct Perfusion ◽  
Iodine Intake ◽  
Tube Voltage ◽  
Effective Radiation Dose ◽  
Low Concentration ◽  
Low Tube Voltage ◽  
Effective Radiation

Aim: To investigate the feasibility of low-concentration contrast (270 mg/ml) together with low tube voltage (80 kV) and adaptive iterative dose reduction (AIDR)-3D reconstruction in liver computed tomography (CT) perfusion imaging. Method: A total of 15 healthy New Zealand rabbits received two CT scans each. The first scan (control) was acquired at 100 kV and 100 mA with iopromide (370 mg/ml), while the second scan (experimental) was acquired at 80 kV and 100 mA with iodixanol (270 mg/ml) 24 h after the first scan. The obtained images were reconstructed with filtered back projection (FBP) and AIDR-3D in the control and experimental groups respectively. The perfusion parameters (hepatic artery perfusion [HAP], portal vein perfusion [PVP], hepatic perfusion index [HPI], and total liver perfusion [TLP]) and image quality (image quality score, average CT value of abdomen aorta, signal-to-noise ratio [SNR], contrast-to-noise ratio [CNR], and figure of merit [FOM]) were compared using a paired t-test or Mann–Whitney U test between the two groups, when appropriate. The effective radiation dose and iodine intake were also recorded and compared. Results: With the exception of the FOM criteria, the image quality and perfusion parameters were not significantly different between the two groups. The effective radiation dose and iodine intake were 38.79% and 27.03% lower respectively, in the experimental group. Conclusion: Low-concentration contrast (iodixanol, 270 mg/ml) together with low tube voltage (80 kV) and AIDR-3D reconstruction help to reduce radiation dose and iodine intake without compromising perfusion parameters and image quality in liver CT perfusion imaging.

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