A comparison study of radiation effective dose in ECG-Gated Coronary CT Angiography and calcium scoring examinations performed with a dual-source CT scanner (original) (raw)
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Radiation Protection Dosimetry, 2013
A retrospective analysis was performed in patients undergoing prospective ECG-triggered coronary computed tomography (CT) angiography (CCTA) with the single-source 64-slice CT (SSCT), dual-source 64-slice CT (DSCT), dual-source 128slice CT and 320-slice CT with the aim of comparing the radiation dose associated with different CT generations. A total of 164 patients undergoing prospective ECG-triggered CCTA with different types of CT scanners were studied with the mean effective doses estimated at 6.8+ + + + +3.2, 4.2+ + + + +1.9, 4.1+ + + + +0.6 and 3.8+ + + + +1.4 mSv corresponding to the 128-slice DSCT, 64-slice DSCT, 64-slice SSCT and 320-slice CT scanners. In this study a positive relationship was found between the effective dose and the body mass index (BMI). A low radiation dose is achieved in prospective ECG-triggered CCTA, regardless of the CT scanner generation. BMI is identified as the major factor that has a direct impact on the effective dose associated with prospective ECG-triggered CCTA.
A retrospective analysis was performed in patients undergoing prospective ECG-triggered coronary computed tomography (CT) angiography (CCTA) with the single-source 64-slice CT (SSCT), dual-source 64-slice CT (DSCT), dual-source 128slice CT and 320-slice CT with the aim of comparing the radiation dose associated with different CT generations. A total of 164 patients undergoing prospective ECG-triggered CCTA with different types of CT scanners were studied with the mean effective doses estimated at 6.8+ + + + +3.2, 4.2+ + + + +1.9, 4.1+ + + + +0.6 and 3.8+ + + + +1.4 mSv corresponding to the 128-slice DSCT, 64-slice DSCT, 64-slice SSCT and 320-slice CT scanners. In this study a positive relationship was found between the effective dose and the body mass index (BMI). A low radiation dose is achieved in prospective ECG-triggered CCTA, regardless of the CT scanner generation. BMI is identified as the major factor that has a direct impact on the effective dose associated with prospective ECG-triggered CCTA.
International Journal of Cancer Therapy and Oncology, 2013
Purpose: To date there is extensive data on the radiation dose for assessing coronary artery calcium scores (CACS) with 4-64 row multidetector MDCT. However with the advent of 320 row MDCT, the entire heart can be imaged in one beat and thus potentially reduce the radiation dose. The aim of this study was to evaluate radiation dose for CACS on low-dose prospective EKG-triggered 320 row MDCT. Materials and Methods: Informed consent for this retrospective HIPAA-compliant study was waived and approved by our institution's institutional review board IRB. One hundred and sixty eight consecutive patients (Male 133 (79%): female 35 (21%), mean body mass index BMI 29±5 and mean heart rate 58± bpm) underwent coronary calcium scoring with prospective gating. The scan parameters were 300 mA, 120 kVp, volume scan length (VSL) 160 mm, gantry rotation 0.350 msec and 320 x 0.5 mm detectors at 320 MDCT. Beta blockers were given to patients in a case heart rate HR > 65 bpm. The effective dose (ED) estimates were calculated for all patients from the dose length product and the conversion factor k (0.014 mSv/mGy/cm) as recommended by current guidelines. Results: The mean SD radiation was 1.89±0.79 mSv. Overall the range varied from 0.28-2.48 mSv. The radiation was significantly less in females as compared to males (2.02±0.73 vs. 1.41±0.87, p<0.0001). No differences were noted whether HR was <60 vs. >=60 bpm (1.87±0.79 vs. 1.77±0.84 mSv, p=0.45). On the other hand a higher radiation was noted among obese individuals as compared to those with BMI<30 (1.84±0.82 vs. 1.91±0.80 mSv, p=0.62). Conclusion: Radiation dose obtained from 320-MDCT is similar to those obtained with 4-64 row MDCT. Further studies are needed to assess the feasibility of further lowering the tube current and tube voltage.
Texas Heart Institute Journal, 2022
Computed tomographic coronary artery calcium scanning enables cardiovascular risk stratification; however, exposing patients to high radiation levels is an ongoing concern. New-generation computed tomographic systems use lower radiation doses than older systems do. To quantify comparative doses of radiation exposure, we prospectively acquired images from 220 patients with use of a 64-slice GE LightSpeed VCT scanner (control group, n=110) and a 256-slice GE Revolution scanner (study group, n=110). The groups were matched for age, sex, and body mass index; statistical analysis included t tests and linear regression. The mean dose-length product was 21% lower in the study group than in the control group (60.2 ± 27 vs 75.9 ± 22.6 mGy·cm; P <0.001) and also in each body mass index subgroup. Similarly, the mean effective radiation dose was 21% lower in the study group (0.84 ± 0.38 vs 1.06 ± 0.32 mSv) and lower in each weight subgroup. After adjustment for sex, women in the study group ...
PloS one, 2016
This study aimed to measure the absorbed doses in selected organs for prospectively ECG-triggered coronary computed tomography angiography (CCTA) using five different generations CT scanners in a female adult anthropomorphic phantom and to estimate the effective dose (HE). Prospectively ECG-triggered CCTA was performed using five commercially available CT scanners: 64-detector-row single source CT (SSCT), 2 × 32-detector-row-dual source CT (DSCT), 2 × 64-detector-row DSCT and 320-detector-row SSCT scanners. Absorbed doses were measured in 34 organs using pre-calibrated optically stimulated luminescence dosimeters (OSLDs) placed inside a standard female adult anthropomorphic phantom. HE was calculated from the measured organ doses and compared to the HE derived from the air kerma-length product (PKL) using the conversion coefficient of 0.014 mSv∙mGy-1∙cm-1 for the chest region. Both breasts and lungs received the highest radiation dose during CCTA examination. The highest HE was rece...
The work is a dosimetric study of cardiac CT scans. Te study involved a signifcant number of patients who have cardiac CT examinations, where the installation used is a 320 detectors scanner. Dosimetric parameters such as CTDIvol, Dose Length Product, PDL, and effective dose were investigated to compare between the contribution of Volume CT and Dynamic CT phases, and to appear the effect of heart rate and tube potential (kVp). Te current work showed that heart rate plays a very important role in the determination of irradiation parameters for the Calcium Score and Coronary-CTA procedures. Also, the contribution of the Dynamic CT phase in the CTDIvol was 80.2% rather than the Volume CT phase was 16.5%. However, the total Dose Length Product and effective dose were very comparable to the Volume CT phase where it contributed with 94%. For modulation by ECG synchronization, the prospective mode demonstrated a great reduction of dose compared to the retrospective mode. Tis study has clearly confrmed that, it is necessary to establish within the teams of doctors and manipulators to scan a true culture of radiation protection
Academic Radiology, 2017
Abbreviations and Acronyms cCTA coronary computed tomography angiography ECG electrocardiographic DSCT dual-source computed tomography ROI region of interest BDP best diastolic phase BSP best systolic phase CNR contrast-to-noise-ratio DLP dose length product Rationale and Objectives: Despite ongoing technical refinements, coronary computed tomography angiography (cCTA) remains challenging in its diagnostic value by electrocardiographic (ECG) misregistration and motion artifacts, which commonly occur in patients with atrial fibrillation and high or irregular heart rates. The aim of this study was to evaluate the radiation dose and the number of inconclusive coronary segments at cCTA using retrospective ECG gating at 100 and 70 kV. Materials and Methods: With institutional review board approval, 154 patients (median age 54 years, 98 men) with high or irregular heart rate prospectively underwent retrospectively ECG-gated cCTA without tube current modulation on a third-generation dual-source computed tomography (DSCT) system at 70 kV (n = 103) or on a second-generation DSCT system at 100 kV (n = 51). Images were reconstructed in best diastolic phase (BDP), best systolic phase (BSP), and in all phases (APs) at 10% intervals across the R-R cycle. Objective and subjective image qualities were evaluated as well as the presence of motion artifacts with the three different reconstruction approaches. Results: The mean heart rate was 93 ± 16 bpm. The mean effective radiation dose was 4.5 mSv for 70 kV compared to 8.4 mSv for 100 kV (P < 0.05). At BDP reconstruction, 71% (n = 110) of the patients showed motion artifacts in one or more coronary segments. At BSP reconstruction, the number of patients with motion artifacts decreased to 37% (n = 57). In contrast, if images were reconstructed with the AP approach, all vessels and coronary segments were evaluable with both cCTA protocols. Conclusions: Retrospectively ECG-gated cCTA at 70 kV results in 52% decreased radiation dose. Further using the AP algorithm allowed for diagnostic evaluation of all coronary segments for stenosis, in contrast to BDP or BSP phase alone.
2015
The aim of this study is to obtain Portuguese cardiac Computed Tomography (CT) Diagnostic Reference Levels (DRLs) and compare the effective dose values with other cardiac examinations performed in Portugal and international studies. Methods: CT dose values and chest anteroposterior diameter (direct measurement on the images) were retrospectively collected in four centres of excellence representing different regions of Portugal, in order to calculate the DRLs based on the 75 th percentile CT values. Results: The sample was composed by 108 individuals, without significant differences inchest diameter. Significant differences were found between local DRL's across the centres. The proposed DRL for cardiac CT is 32mGy. The obtained cardiac CT effective dose value is higher than a diagnostic angiography and similar to a cardiac angioplasty. Conclusions: The obtained dose values should be optimised. Procedures justification must be reconsidered and the radiation examinations risk must be analysed taking into account the clinical indications.