scholarly journals Patient-Specific Radiation Dose and Cancer Risk Estimate in Computed Tomography Pulmonary Angiography Examinations Based on Lung Effective Diameter

2019 ◽  
Author(s):  
Hanif Haspi Harun ◽  
Muhammad Khalis Abdul Karim ◽  
Zulkifly Abbas ◽  
Sarawana Chelwan Muniandy ◽  
Akmal Sabarudin ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Radiation Dose ◽  
Cancer Risk ◽  
Radiation Exposure ◽  
Effective Dose ◽  
Organ Dose ◽  
Pulmonary Angiography ◽  
Effective Diameter ◽  
Computed Tomography Pulmonary Angiography ◽  
Radiation Dose Exposure

Computed Tomography (CT) scan examinations has greater demands especially in CT Pulmonary Angiography (CTPA) owing to the public and radiology personnel worries towards CT radiation exposure and risks. The aim of present study is to evaluate the comprehensive radiation exposure in computed tomography pulmonary angiography (CTPA) and its cancer risk. The records of 100 patients who had undergone CTPA were retrieved. The radiation dose exposure, scanning acquisition protocol as well as patient characteristics were noted. Radiation exposure were presented as Volume Computed Tomography Dose Index (CTDIvol), Size-Specific Dose Estimate (SSDE), Dose-Length Product (DLP), and effective dose (E) and organ dose. Effective cancer risk per million procedure was calculated by referring to the International Commission on Radiological Protection Publication 103. The CTDIvol, SSDE, DLP were comparable within different effective diameter groups. The average effective dose received by a patient was 8.68 mSv. The organ dose and effective cancer risk attained for breast, lung and liver were 17.05 ± 10.40 mGy (194 per one million procedure), 17.55 ± 10.86 mGy (192 per one million procedure) and 15.04 ± 9.75 mGy (53 per one million procedure), respectively. In conclusion, CTDIvol was undervalued and SSDE was more accurate in describing radiation dose exposure. The lungs and breast of subjects with large effective diameter were higher risk of developing cancer as they received the highest exposure. Therefore, extra safety measures should be considered for large-sized patients undergoing CTPA.Purpose: This study evaluates the comprehensive radiation exposure in computed tomography pulmonary angiography (CTPA) and its cancer risk.

scholarly journals Radiation Doses and Cancer Risk from CT Pulmonary Angiography Examinations

2019 ◽  
Author(s):  
Hanif Haspi Harun ◽  
Muhammad Khalis Abdul Karim ◽  
Zulkifly Abbas ◽  
Sarawana Chelwan Muniandy ◽  
Akmal Sabarudin ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Radiation Dose ◽  
Cancer Risk ◽  
Organ Dose ◽  
Pulmonary Angiography ◽  
Effective Diameter ◽  
Radiological Protection ◽  
Radiation Doses ◽  
Dose Length Product ◽  
The Mean

The present study aims to investigate radiation doses from Computed Tomography Pulmonary Angiography (CTPA) examinations based on the patient’s size and to estimate the probability of cancer risk induced from the examination. Data from 100 patients who had undergone CTPA examinations, such as scanning acquisition parameters, patient demography, as well as radiation dose exposure, were collected and analysed. All subjects which aged above 18 y/o were scanned using a Philips Brilliance 128 multi-detector CT (MDCT) scanner. The mean dose value for Volume Computed Tomography Dose Index (CTDIvol), Dose-Length Product (DLP) and effective dose (E) were 11.06 ± 7.17 mGy, 400.38 ± 259.10 mGy.cm and 8.68 ± 5.47 mSv respectively. In addition, with respective of patient’s effective diameter, the mean SSDE value for Group 1, Group 2 and Group 3 were 9.93 ± 3.89, 13.70 ± 9.04 and 22.29 ± 7.35, respectively. Cancer risk per million procedure was calculated based on te recommendation by the International Commission on Radiological Protection Publication 103 report. The organ dose and cancer risk attained for breast, lung and liver were 17.05 ± 10.40 mGy (194 per one million procedure), 17.55 ± 10.86 mGy (192 per one million procedure) and 15.04 ± 9.75 mGy (53 per one million procedure), respectively. In conclusion, CTDIvol underestimated, and SSDE was more accurate in describing the radiation dose. Lung and breast with larger lung effective diameter received the highest dose exposure which increase the probability of the cancer risk. Therefore, it is important to apply optimised protocols in order to reduce patient’s exposure during CTPA examination.

scholarly journals Effect of Lowering Tube Potential and Increase Iodine Concentration of Contrast Medium on Radiation Dose and Image Quality in Computed Tomography Pulmonary Angiography Procedure: A Phantom Study

2021 ◽  
Vol 47 (3) ◽  
pp. 1211-1224
Author(s):  
Justin E Ngaile ◽  
Peter K Msaki ◽  
Evarist M Kahuluda ◽  
Furaha M Chuma ◽  
Jerome M Mwimanzi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Radiation Dose ◽  
Contrast Medium ◽  
Iodine Concentration ◽  
Pulmonary Angiography ◽  
Computed Tomography Pulmonary Angiography ◽  
Iodinated Contrast ◽  
Tube Potential ◽  
Tube Current

The aim of the study was to examine the effect of lowering tube potential and increase iodine concentration on image quality and radiation dose in computed tomography pulmonary angiography procedure. The pulmonary arteries were simulated by three syringes. The syringes were filled with 1:10 diluted solutions of 300 mg, 350 mg and 370 mg of iodine per millilitre concentration in three water-filled phantoms simulating thin, intermediate and thick patients. The phantoms were scanned at 80 kVp, 110 kVp and 130 kVp and 0.6 second rotation time using a 16 slice computed tomography (CT) scanner. The tube current was either fixed at 80, 100, 200, 250 and 300 mA or automatically adjusted with quality reference tube current-time product (mAsQR). In comparison with 130 kVp, images acquired at 80 kVp and 110 kVp, respectively, showed 76.2% to 99% and 19% to 26% enhancement in CT attenuation of iodinated contrast material. A volume CT dose index (CTDIvol) reduction by 35.3% was attained in small phantom with the use of 80 kVp, while in the medium phantom, a CTDIvol reduction by 29.9% was attained with the use of 110 kVp instead of 130 kVp. In light of the above, lowering tube potential and increase iodinated CM could substantially reduce the dose to small-sized adults and children. Keywords: Angiography; Computed tomography; Low tube potential; Iodinated contrast medium; Radiation dose

scholarly journals Computed Tomography Pulmonary Angiography during Pregnancy: Radiation Dose of Commonly Used Protocols and the Effect of Scan Length Optimization

2019 ◽  
Vol 20 (2) ◽  
pp. 313 ◽  
Author(s):  
Babs M.F. Hendriks ◽  
Roald S. Schnerr ◽  
Gianluca Milanese ◽  
Cécile R.L.P.N. Jeukens ◽  
Sandra Niesen ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Radiation Dose ◽  
Pulmonary Angiography ◽  
Computed Tomography Pulmonary Angiography ◽  
Length Optimization ◽  
Scan Length

scholarly journals Thoracic Organ Doses and Cancer Risk from Low Pitch Helical 4-Dimensional Computed Tomography Scans

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Chengwen Yang ◽  
Ransheng Liu ◽  
Xin Ming ◽  
Ningbo Liu ◽  
Yong Guan ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cancer Risk ◽  
Organs At Risk ◽  
Organ Dose ◽  
Effective Diameter ◽  
Average Dose ◽  
Monte Carlo Code ◽  
Organ Doses ◽  
Younger Age ◽  
Risk Of Cancer

Purpose. To investigate the dose depositions to organs at risk (OARs) and associated cancer risk in cancer patients scanned with 4-dimensional computed tomography (4DCT) as compared with conventional 3DCT. Methods and Materials. The radiotherapy treatment planning CT image and structure sets of 102 patients were converted to CT phantoms. The effective diameters of those patients were computed. Thoracic scan protocols in 4DCT and 3DCT were simulated and verified with a validated Monte Carlo code. The doses to OARs (heart, lungs, esophagus, trachea, spinal cord, and skin) were calculated and their correlations with patient effective diameter were investigated. The associated cancer risk was calculated using the published models in BEIR VII reports. Results. The average of mean dose to thoracic organs was in the range of 7.82-11.84 cGy per 4DCT scan and 0.64-0.85 cGy per 3DCT scan. The average dose delivered per 4DCT scan was 12.8-fold higher than that of 3DCT scan. The organ dose was linearly decreased as the function of patients’ effective diameter. The ranges of intercept and slope of the linear function were 17.17-30.95 and -0.0278--0.0576 among patients’ 4DCT scans, and 1.63-2.43 and -0.003--0.0045 among patients’ 3DCT scans. Relative risk of cancer increased (with a ratio of 15.68:1) resulting from 4DCT scans as compared to 3DCT scans. Conclusions. As compared to 3DCT, 4DCT scans deliver more organ doses, especially for pediatric patients. Substantial increase in lung cancer risk is associated with higher radiation dose from 4DCT and smaller patients’ size as well as younger age.

scholarly journals The Effect of Limiting the Scan Range of Computed Tomography Pulmonary Angiography (to Reduce Radiation Exposure) on the Detection of Pulmonary Embolism: A Systematic Review

Diagnostics ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2179
Author(s):  
Amayar Zaw ◽  
Rebecca Nguyen ◽  
Leon Lam ◽  
Anthony Kaplan ◽  
Claudia C. Dobler
Keyword(s):  
Computed Tomography ◽  
Pulmonary Embolism ◽  
High Risk ◽  
Radiation Exposure ◽  
Aortic Arch ◽  
Filling Defect ◽  
Pulmonary Angiography ◽  
Risk Of Bias ◽  
Secondary Outcome ◽  
Computed Tomography Pulmonary Angiography

(1) Background: Computed tomography pulmonary angiography (CTPA) is the standard imaging test for the evaluation of acute pulmonary embolism (PE), but it is associated with patients’ exposure to radiation. Studies have suggested that radiation exposure can be reduced without compromising PE detection by limiting the scan range (the z-axis, going from up to down); (2) Methods: A literature search was conducted in MEDLINE and EMBASE on 17 July 2021. Studies were included if they enrolled patients who had undergone a CTPA and described the yield of PE diagnoses, number of missed filling defects and/or other diagnoses using a reduced z-axis in comparison to a full-length scan. To assess risk of bias, we modified an existing risk of bias tools for observational studies, the Newcastle-Ottawa Scale. Results were synthesized in a narrative review. Primary outcomes were the number of missed PE diagnoses (based on at least one filling defect) and filling defects; the secondary outcome was the number of other missed findings; (3) Results: Eleven cohort studies and one case-control study were included reporting on a total of 3955 scans including 1025 scans with a diagnosis of PE. Six different reduced scan ranges were assessed; the most studied was from the top of the aortic arch to below the heart, in which no PEs were missed (seven studies). One sub-segmental PE was missed when the scan coverage was 10 cm starting from the bottom of the aortic arch and 14.7 cm starting from the top of the arch. Five studies that reported on other findings all found that other diagnoses were missed with a reduced z-axis. Most of the included studies had a high risk of bias; (4) Conclusions: CTPA scan coverage reduction from the top of aortic arch to below the heart reduced radiation exposure without affecting PE diagnoses, but studies were generally at high risk of bias.

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