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.

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.

scholarly journals Safety of the effective radiation dose received during stroke hospitalization

2021 ◽  
Vol 20 ◽  
Author(s):  
Gregório Platero Canton ◽  
Gustavo José Luvizutto ◽  
Pedro Tadao Hamamoto Filho ◽  
Marcos Ferreira Minicucci ◽  
Gabriel Pinheiro Modolo ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Ct Perfusion ◽  
Cross Sectional Study ◽  
Stroke Severity ◽  
Clinical Classification ◽  
National Guidelines ◽  
Effective Radiation Dose ◽  
Cross Sectional ◽  
The Difference ◽  
Effective Radiation

Abstract Background Neuroimaging is widely used for diagnosis and treatment of stroke. However, little is known about whether the radiation doses received by patients comply with international safety guidelines. Objectives The aim of this study was to evaluate the effective radiation dose received while in hospital for stroke and analyze its safety according to current guidelines. Methods This cross-sectional study included 109 patients who were hospitalized and diagnosed with ischemic stroke. The National Institutes of Health Stroke Scale was used to evaluate stroke severity, the Bamford clinical classification was used for topography, and the TOAST classification was used for etiology. The computed tomography dose index and size-specific dose estimates were used to calculate the effective radiation dose (ERD) received while in hospital. A Mann-Whitney test was used to compare the ERD received by thrombolysed and non-thrombolysed patients. Non-parametric statistics were used to analyze the data with a 95% confidence interval. Results During the study period, the median ERD received was 10.9 mSv. Length of stay was not associated with radiation exposure. No differences were demonstrated in ERD according to stroke etiology or Bamford clinical classification. Patients who had CT perfusion (only or in addition to CT or angiotomography) received the highest ERD (46.5 mSv) and the difference compared to those who did not (10.8 mSv) was statistically significant (p<0.001). No differences were found in the ERD between thrombolysed and non-thrombolysed patients. There was no correlation between ERD while in hospital and stroke severity. Conclusions According to the current national guidelines, the protocol for examining images at our stroke unit is safe in terms of the ERD received by the patient while in hospital. There was no difference in the ERD received by patients stratified by thrombolytic treatment or stroke severity.

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.

EFFECTIVE RADIATION DOSE OF 18F-FDG PET/CT: HOW MUCH DOES DIAGNOSTIC CT CONTRIBUTE?

2019 ◽  
Vol 187 (2) ◽  
pp. 183-190 ◽  
Author(s):  
Yuhao Li ◽  
Lisha Jiang ◽  
Haitao Wang ◽  
Huawei Cai ◽  
Yongzhao Xiang ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Radiation Dose ◽  
Total Dose ◽  
Radiation Doses ◽  
Effective Radiation Dose ◽  
Positron Emission ◽  
Pet Ct ◽  
Effective Doses ◽  
Fdg Pet Ct ◽  
Effective Radiation

Abstract The aim was to estimate the effective doses associated with different types of scanning protocols and how much the diagnostic computed tomography (DCT) scan contributed to the total dose of the dual-modality positron emission tomography/computed tomography (PET/CT) examinations. The results showed that an average radiation dose of 8.19 ± 0.83 mSv and 13.44 ± 5.14 mSv for the PET and CT components, respectively, resulting in a total dose of 21.64 ± 5.20 mSv. Approximately 92.7% (980 of 1057) of the patients underwent additional DCT protocols. The DCT protocols contributed 42% of the overall effective radiation doses, which was larger than the percentage contributed by the PET component (38%) and LCT protocols (20%). Reducing the diagnostic area of the DCT scans that patients undergo and decreasing the use of chest-abdomen-pelvis (CAP), abdomen-pelvis (AP) and chest DCT protocols, especially the CAP protocol, will be helpful in decreasing the effective radiation doses of PET/CT scan.

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.

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