scholarly journals Reducing fetal radiation dose in computed tomography for pregnant patients: A literature review

2021 ◽  
Vol 2 (4) ◽  
pp. 35-43
Author(s):  
Hamid Ghaznavi ◽  
Keyword(s):  
Computed Tomography ◽  
Pulmonary Embolism ◽  
Radiation Dose ◽  
Renal Stones ◽  
Gestation Period ◽  
Ct Examination ◽  
Golden Standard ◽  
Ionization Radiation ◽  
Radiation Beams ◽  
Fetal Dose

To diagnose diseases during gestation period including renal stones, appendicitis, and pulmonary embolism in pregnant patients, computed tomography (CT) can be a golden standard. Due to CT examination, the fetus is prone to receiving a considerable dose which is the result of direct or scattered (external and internal scattered radiation) beams. The effects of ionization radiation on fetus include mutagenesis and carcinogenesis, therefore, it is essential to reduce fetus dose for pregnant patients who undergo CT examination during gestation period. This article aims to review approaches that are effective in reducing fetal dose in pregnant patients.

Using 100- instead of 120-kVp computed tomography to diagnose pulmonary embolism almost halves the radiation dose with preserved diagnostic quality

2010 ◽  
Vol 51 (3) ◽  
pp. 260-270 ◽  
Author(s):  
Peter Björkdahl ◽  
Ulf Nyman
Keyword(s):  
Computed Tomography ◽  
Pulmonary Embolism ◽  
Image Quality ◽  
Radiation Dose ◽  
Effective Dose ◽  
Ct Number ◽  
Subjective Image Quality ◽  
Diagnostic Quality ◽  
X Ray ◽  
Tube Potential

Background: Concern has been raised regarding the mounting collective radiation doses from computed tomography (CT), increasing the risk of radiation-induced cancers in exposed populations. Purpose: To compare radiation dose and image quality in a chest phantom and in patients for the diagnosis of pulmonary embolism (PE) at 100 and 120 peak kilovoltage (kVp) using 16-multichannel detector computed tomography (MDCT). Material and Methods: A 20-ml syringe containing 12 mg I/ml was scanned in a chest phantom at 100/120 kVp and 25 milliampere seconds (mAs). Consecutive patients underwent 100 kVp ( n = 50) and 120 kVp ( n = 50) 16-MDCT using a “quality reference” effective mAs of 100, 300 mg I/kg, and a 12-s injection duration. Attenuation (CT number), image noise (1 standard deviation), and contrast-to-noise ratio (CNR; fresh clot = 70 HU) of the contrast medium syringe and pulmonary arteries were evaluated on 3-mm-thick slices. Subjective image quality was assessed. Computed tomography dose index (CTDIvol) and dose–length product (DLP) were presented by the CT software, and effective dose was estimated. Results: Mean values in the chest phantom and patients changed as follows when X-ray tube potential decreased from 120 to 100 kVp: attenuation +23% and +40%, noise +38% and +48%, CNR −6% and 0%, and CTDIvol −38% and −40%, respectively. Mean DLP and effective dose in the patients decreased by 42% and 45%, respectively. Subjective image quality was excellent or adequate in 49/48 patients at 100/120 kVp. No patient with a negative CT had any thromboembolism diagnosed during 3-month follow-up. Conclusion: By reducing X-ray tube potential from 120 to 100 kVp, while keeping all other scanning parameters unchanged, the radiation dose to the patient may be almost halved without deterioration of diagnostic quality, which may be of particular benefit in young individuals.

scholarly journals Factors Affecting Radiation Dose in Computed Tomography Angiograms for Pulmonary Embolism: A Retrospective Cohort Study

2020 ◽  
Vol 10 ◽  
pp. 74
Author(s):  
Prashant Nagpal ◽  
Sarv Priya ◽  
Ali Eskandari ◽  
Aidan Mullan ◽  
Tanya Aggarwal ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Pulmonary Embolism ◽  
Radiation Dose ◽  
Care Center ◽  
Tertiary Care ◽  
Multivariate Logistic Regression Analysis ◽  
Factors Affecting ◽  
Model Based ◽  
Pulmonary Angiogram ◽  
The Mean

Objectives: Computed tomography pulmonary angiogram (CTPA) is one of the most commonly ordered and frequently overused tests. The purpose of this study was to evaluate the mean radiation dose to patients getting CTPA and to identify factors that are associated with higher dose. Material and Methods: This institutionally approved retrospective study included all patients who had a CTPA to rule out acute pulmonary embolism between 2016 and 2018 in a tertiary care center. Patient data (age, sex, body mass index [BMI], and patient location), CT scanner type, image reconstruction methodology, and radiation dose parameters (dose-length product [DLP]) were recorded. Effective dose estimates were obtained by multiplying DLP by conversion coefficient (0.014 mSv•mGy−1•cm−1). Multivariate logistic regression analysis was performed to determine the factors affecting the radiation dose. Results: There were 2342 patients (1099 men and 1243 women) with a mean age of 58.1 years (range 0.2–104.4 years) and BMI of 31.3 kg/m2 (range 12–91.5 kg/m2). The mean effective radiation dose was 5.512 mSv (median – 4.27 mSv; range 0.1–43.0 mSv). Patient factors, including BMI >25 kg/m2, male sex, age >18 years, and intensive care unit (ICU) location, were associated with significantly higher dose (P < 0.05). CT scanning using third generation dual-source scanner with model-based iterative reconstruction (IR) had significantly lower dose (mean: 4.90 mSv) versus single-source (64-slice) scanner with filtered back projection (mean: 9.29 mSv, P < 0.001). Conclusion: Patients with high BMI and ICU referrals are associated with high CT radiation dose. They are most likely to benefit by scanning on newer generation scanner using advance model-based IR techniques.

Radiation Dose and Somatic Risk from Computed Tomography

1987 ◽  
Vol 28 (4) ◽  
pp. 483-488 ◽  
Author(s):  
K. Faulkner ◽  
B. M. Moores
Keyword(s):  
Computed Tomography ◽  
Radiation Dose ◽  
Male Patient ◽  
Dose Distribution ◽  
Lithium Fluoride ◽  
Central Axis ◽  
Organ Doses ◽  
Ct Examination ◽  
Genetic Risks ◽  
Thermoluminescent Dosemeters

Lithium fluoride (LiF) thermoluminescent dosemeters (TLD) have been employed to measure the radiation dose distribution within a phantom and the central axis dose in air. Results are presented for seven (four EMI CT1010, one EMI CT5005, one EMI CT7070 and one Siemens DR2) different machines. Organ doses for four different computed tomography (CT) investigations (head, lung, liver and pelvis) have been estimated from previously published tables and the central axis dose in air in 3 CT units. These estimated organ doses were used in turn to deduce the somatic and genetic risks for the four types of CT examination. These calculations indicate that for an ‘average’ male patient undergoing a CT examination corresponding to the average conditions encountered, the total somatic risks are 3.15 10−4, 1.98 10−4, 2.31 10−4, and 1.38 10−4 for head, lung, liver and pelvis scans, respectively. The corresponding figures for female patients are 3.39 10−4, 3.95 10−4, 2.73 10−4, and 1.60 10−4. The risk from head scanning is approximately 250 times that of a dental pantomograph. Somatic and genetic risks will be approximately twice as high for contrast examinations.

scholarly journals Occupational Radiation Dose, Especially for Eye Lens: Hp(3), in Medical Staff Members Involved in Computed Tomography Examinations

2021 ◽  
Vol 11 (10) ◽  
pp. 4448
Author(s):  
Minoru Osanai ◽  
Hidenori Sato ◽  
Kana Sato ◽  
Kohsei Kudo ◽  
Masahiro Hosoda ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Radiation Dose ◽  
Radiation Protection ◽  
Medical Staff ◽  
Shielding Effect ◽  
Eye Lens ◽  
Radiological Protection ◽  
Ct Examination ◽  
Radiation Dose Exposure ◽  
Occupational Radiation

Radiation dose management of medical staff has become increasingly important. Particularly, based on the statement by the International Commission on Radiological Protection (ICRP) in 2011, a new lower equivalent dose limit for the eye lens is being established in each country. Although many reports have discussed the occupational radiation dose in interventional radiology (IR), few studies have examined the dose during computed tomography (CT) examinations. This study investigated the radiation dose exposure to medical staff present in the CT room during irradiation, with particular focus on the exposure to eye lens. The radiation dose exposure to those who assist patients during head, chest and upper abdomen CT examination was measured in a phantom study. The radiation dose exposure with scattered radiation was never negligible (i.e., high); Hp(3) was the highest in head CT examination, at 0.44 mSv per examination. Furthermore, the shielding effect of radiation protection glasses was large, and radiation protection glasses are useful tools for the medical staff who are involved in CT examinations. The justification and optimisation should be carefully considered in assistant actions.

DEVELOPMENT OF A SPECIALISED TAPE MEASURE TO ESTIMATE THE SIZE-SPECIFIC DOSE ESTIMATE

2020 ◽  
Vol 191 (3) ◽  
pp. 369-375
Author(s):  
Tomokazu Shohji ◽  
Kazuki Kuriyama ◽  
Nobutaka Yanano ◽  
Yo Katoh
Keyword(s):  
Computed Tomography ◽  
Radiation Dose ◽  
Radiation Exposure ◽  
Ct Images ◽  
Ct Scans ◽  
Dose Estimate ◽  
Ct Examination ◽  
Tape Measure ◽  
Wide Range ◽  
Standard Deviations

Abstract The risk in computed tomography (CT) examinations is radiation exposure. We aimed to develop a specialised tape measure for determining the size-specific dose estimate (SSDE) for patients undergoing CT scans. The scanning parameters used were those of the abdominal protocol in our institute. With this method, the SSDE220 and standard deviations obtained from CT images for the liver, pelvic and lung areas, corresponded closely to the SSDEtape and standard deviations obtained using the tape measure. We thus devised a new idea that allows the estimation of the SSDE220 using a specialised tape measure before the CT examination, allowing for an informed explanation of the radiation dose to the patient. Although the tape measure developed in this study is specific to one particular CT instrument, the method could be adapted to a wide range of radiography applications.

scholarly journals Do you know the radiation dose your patients receive from your CT scanner?

2001 ◽  
Vol 5 (2) ◽  
pp. 30-34
Author(s):  
Chris Welman ◽  
Savvas Andronikou ◽  
Ebrahim Kader
Keyword(s):  
Computed Tomography ◽  
Radiation Dose ◽  
Ct Scanner ◽  
Ct Examination ◽  
Probability Of Cancer ◽  
Medical Examinations ◽  
Dose Reductions

The number of computed tomography (CT) examinations and new indications for CT are increasing in frequency worldwide. While CT makes up only 4% of medical examinations, it might contribute as much as 40% of the total collective radiation dose to the population. Radiologists and referring clinicians should make sure that the CT examination is indicated. Doses can often approach or exceed levels known to increase the probability of cancer. This is especially relevant in children where dose reductions of up to 80% can be obtained by adjusting the exposure factors. The most important factors are decreased milliampere seconds (mAs) and increased pitch.

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