Abstract 5802: Whole-Heart Coronary Angiography using Volume Computed Tomography in Comparison to Conventional Coronary Angiography

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Marc Dewey ◽  
Elke Zimmermann ◽  
Florian Deissenrieder ◽  
Michael Laule ◽  
Hans-Peter Dübel ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Radiation Dose ◽  
Coronary Angiography ◽  
Coronary Ct Angiography ◽  
Conventional Coronary Angiography ◽  
Effective Radiation Dose ◽  
Initial Report ◽  
Coronary Ct ◽  
Whole Heart ◽  
Effective Radiation

This is an initial report on the use of the recently introduced whole-heart 320-slice computed tomography (CT) scanner for noninvasive coronary angiography compared with conventional coronary angiography (CCA). Whole-heart CT avoids overscanning and overranging as necessary for helical coronary CT acquisitions thereby significantly reducing the effective radiation dose. Twelve patients with suspected coronary artery disease (4 women, 8 men; mean age 64.6 ± 11 years) have undergone coronary CT angiography using a 320-slice scanner (Aquilion ONE, Toshiba; 0.35 s gantry rotation time, 120 kV, and 350 – 450 mA) prior to clinically indicated CCA. CT images were manually reconstructed in motion-free phases with 0.5-mm slice thickness and 0.25-mm slice increment. Independent blinded assessment of CT and CCA (using quantitative analysis) was performed to detect significant (at least 50%) diameter stenoses. Of the 12 patients, in 8 patients, single-heart beat CT acquisition was performed, resulting in an effective dose of 5.6 ± 1.1 mSv and an image reconstruction window length of 175 msec. In the other 4 patients, because of higher heart rates, 2 or 3 heart beats were used for acquisition, resulting in higher radiation exposure (on average 17 mSv) and the possibility to perform multisegment reconstruction with improved temporal resolution (88 and 58 msec image reconstruction windows, respectively). Per-patient sensitivity and specificity for CT compared to CCA were 100%. Per-vessel sensitivity and specificity were 88% and 95%, respectively. Intraindividual comparison of CT with CCA revealed a nonsignificantly smaller effective radiation dose (9.4 ± 7.2 mSv vs. 10.5 ± 5.3 mSv, p<0.69) but significantly smaller contrast agent amount (80 ±0 ml vs. 107.3 ± 17.8 ml, p<0.01) for 320-slice CT. Whole-heart CT significantly reduces the contrast agent amount compared to CCA while radiation exposure is reduced in patients with slow heart rates. This initial report also indicates that diagnostic accuracy of coronary CT angiography using up to 320 simultaneous detector rows remains high as compared with CCA as the reference standard.

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.

CBCT IN CONSERVATIVE DENTISTRY AND ENDODONTICS - A REVIEW

2013 ◽  
Vol 5 (2) ◽  
pp. 52-55
Author(s):  
Prakash Lokhande ◽  
G.B SHIVAMURTHY ◽  
SAURAV KR SRIVASTAVA
Keyword(s):  
Computed Tomography ◽  
Radiation Dose ◽  
Three Dimensional ◽  
Conventional Radiography ◽  
Cone Beam ◽  
Effective Radiation Dose ◽  
Conservative Dentistry ◽  
Effective Radiation ◽  
Endodontic Disease ◽  
Review Current

ABSTRACT Cone beam computed tomography (CBCT) has been specifically designed to produce undistorted three-dimensional information of the maxillofacial skeleton, including the teeth and their surrounding tissues with a significantly lower effective radiation dose compared with conventional computed tomography (CT). The system overcomes many of the limitations of conventional radiography by producing undistorted, three-dimensional images of the area under examination. These properties make this form of imaging particularly suitable for use in endodontics. The clinician can obtain an enhanced appreciation of the anatomy being assessed, leading to an improvement in the detection of endodontic disease and resulting in more effective treatment planning. In addition, CBCT operates with a significantly lower effective radiation dose when compared with conventional computed tomography (CT). The aim of this paper is to review current literature on the applications and limitations of CBCT in the management of endodontic problems.

Ultra-low-dose computed tomography and its utility in wrist trauma in the emergency department

2021 ◽  
pp. 028418512198995
Author(s):  
Erdal Tekin ◽  
Kutsi Tuncer ◽  
Ibrahim Ozlu ◽  
Recep Sade ◽  
Rustem Berhan Pirimoglu ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Radiation Dose ◽  
Low Dose ◽  
Standard Dose ◽  
Control Group ◽  
Study Group ◽  
Effective Radiation Dose ◽  
Wrist Trauma ◽  
Effective Radiation

Background The use and frequency of computed tomography (CT) are increasing day by day in emergency departments (ED). This increases the amount of radiation exposed. Purpose To evaluate the image quality obtained by ultra-low-dose CT (ULDCT) in patients with suspected wrist fractures in the ED and to investigate whether it is an alternative to standard-dose CT (SDCT). Material and Methods This is a study prospectively examining 336 patients who consulted the ED for wrist trauma. After exclusion criteria were applied, the patients were divided into the study and control groups. Then, SDCT (120 kVp and 100 mAs) and ULDCT (80 kVp and 5 mAs) wrist protocols were applied simultaneously. The images obtained were evaluated for image quality and fracture independently by a radiologist and an emergency medical specialist using a 5-point scale. Results The effective radiation dose calculated for the control group scans was 41.1 ± 2.1 µSv, whereas the effective radiation dose calculated for the study group scans was 0.5 ± 0.0 µSv. The effective radiation dose of the study group was significantly lower than that of the control group ( P < 0.01). The CT images in the study group showed no significant differences in the mean image quality score between observer 1 and observer 2 (3.4 and 4.3, respectively; P = 0.58). Both observers could detect all fractures using the ULDCT images. Conclusion ULDCT provides high-quality images in wrist traumas while reducing the radiation dose by approximately 98% compared to SDCT without any changes in diagnostic accuracy.

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