scholarly journals CT Pulmonary Angiogram with Reduced Radiation Exposure at Low Tube Kilovoltage

2020 ◽  
Vol 14 (2) ◽  
Author(s):  
Ahmed Abdullahi Hashi
Keyword(s):  
Pulmonary Embolism ◽  
Radiation Dose ◽  
Contrast Enhancement ◽  
Low Dose ◽  
Reconstruction Algorithm ◽  
Diagnostic Value ◽  
Considerable Decrease ◽  
Low Tube Voltage ◽  
Pulmonary Angiogram ◽  
Group B

This study's primary goal is to assess the image quality and radiation dose of the low-dose 80kV computed tomography pulmonary angiogram (CTPA) protocol compared to the standard 100kV CTPA protocol for the assessment of pulmonary embolism (PE). The study consisted of 100 patients who had clinically suspected pulmonary embolism and required a CTPA. Patients underwent imaging with a 320-row multi-detector Toshiba Aquilion One Genesis Edition in the absence of the proprietary radiation reduction software known as forward projected model-based Iterative Reconstruction Solution (commercial acronym 'FIRST'). Participants were divided into two groups: A and B.  Group A was composed of 50 patients who were allocated to standard CT protocol using a 100 kV exposure setting and all other settings set as a standard by the manufacturer.  Group B was composed of 50 patients who were allocated to a CTPA with a low-dose 80kV protocol, standard deviation level 8, an effective mAs of 258, reconstruction algorithm-kernel FC 51 within the lung window, and tube current modulation. A considerable decrease in radiation dose was observed with the low-dose CTPA protocol. The mean radiation dose was also decreased by 66% while using the 80kV protocol than when utilising a standard 100kV technique; this was achieved without compromising this study's diagnostic value. Furthermore, the contrast enhancement was considerably more significant, up to 40% higher when using 80kV. The study found that a low tube voltage of 80kV CTPA protocol resulted in a considerable decrease in radiation dose and improved contrast enhancement without sacrificing the examinations' diagnostic utility.

A Systematic Review of Double Low-dose CT Pulmonary Angiography in Pulmonary Embolism

2019 ◽  
Vol 15 (5) ◽  
pp. 453-460 ◽  
Author(s):  
Sultan Aldosari ◽  
Zhonghua Sun
Keyword(s):  
Systematic Review ◽  
Pulmonary Embolism ◽  
Image Quality ◽  
Radiation Dose ◽  
Contrast Medium ◽  
Low Dose ◽  
Pulmonary Angiography ◽  
Ct Pulmonary Angiography ◽  
Low Contrast ◽  
Low Contrast Medium

Background: The aim of this study is to perform a systematic review of the feasibility and clinical application of double low-dose CT pulmonary angiography (CTPA) in the diagnosis of patients with suspected pulmonary embolism. Discussion: A total of 13 studies were found to meet selection criteria reporting both low radiation dose (70 or 80 kVp versus 100 or 120 kVp) and low contrast medium dose CTPA protocols. Lowdose CTPA resulted in radiation dose reduction from 29.6% to 87.5% in 12 studies (range: 0.4 to 23.5 mSv), while in one study, radiation dose was increased in the dual-energy CT group when compared to the standard 120 kVp group. CTPA with use of low contrast medium volume (range: 20 to 75 ml) was compared to standard CTPA (range: 50 to 101 ml) in 12 studies with reduction between 25 and 67%, while in the remaining study, low iodine concentration was used with 23% dose reduction achieved. Quantitative assessment of image quality (in terms of signal-to-noise ratio and contrast-to-noise ratio) showed that low-dose CTPA was associated with higher, lower and no change in image quality in 3, 3 and 6 studies, respectively when compared to the standard CTPA protocol. The subjective assessment indicated similar image quality in 11 studies between low-dose and standard CTPA groups, and improved image quality in 1 study with low-dose CTPA. Conclusion: This review shows that double low-dose CTPA is feasible in the diagnosis of pulmonary embolism with significant reductions in both radiation and contrast medium doses, without compromising diagnostic image quality.

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.

scholarly journals ECG in suspected pulmonary embolism

2019 ◽  
Vol 95 (1119) ◽  
pp. 12-17 ◽  
Author(s):  
Duncan Thomson ◽  
Georgios Kourounis ◽  
Rebecca Trenear ◽  
Claudia-Martina Messow ◽  
Petr Hrobar ◽  
...  
Keyword(s):  
Pulmonary Embolism ◽  
Hospital Setting ◽  
District General Hospital ◽  
Diagnostic Value ◽  
Suspected Pulmonary Embolism ◽  
Ecg Changes ◽  
Retrospective Case ◽  
Strain Pattern ◽  
Pulmonary Angiogram ◽  
Large Clot

ObjectiveTo establish the diagnostic value of prespecified ECG changes in suspected pulmonary embolism (PE).MethodsRetrospective case–control study in a district general hospital setting. We identified 189 consecutive patients with suspected PE whose CT pulmonary angiogram (CTPA) was positive for a first PE and for whom an ECG taken at the time of presentation was available. We matched these for age±3 years with 189 controls with suspected PE whose CTPA was negative. We considered those with large (n=76) and small (n=113) clot load separately. We scored each ECG for the presence or absence of eight features that have been reported to occur more commonly in PE.Results20%–25% of patients with PE, including those with large clot load, had normal ECGs. The most common ECG abnormality in patients with PE was sinus tachycardia (28%). S1Q3T3 (3.7%), P pulmonale (0.5%) and right axis deviation (4.2%) were infrequent findings. Right bundle branch block (9.0%), atrial dysrhythmias (10.1%) and clockwise rotation (20.1%) occurred more frequently but were also common in controls. Right ventricular (RV) strain pattern was significantly more commonly in patients than controls, 11.1% vs 2.6% (sensitivity 11.1%, specificity 97.4%; OR 4.58, 95% CI 1.63 to 15.91; p=0.002), particularly in those with large clot load, 17.1% vs 2.6% (sensitivity 17.1%, specificity 97.4%; OR 7.55, 95% CI 1.62 to 71.58; p=0.005).ConclusionAn ECG showing RV strain in a breathless patient is highly suggestive of PE. Many of the other ECG changes that have been described in PE occur too infrequently to be of predictive value.

First experiences of a low-dose protocol for CT-guided musculoskeletal biopsies combining different radiation dose reduction techniques

2019 ◽  
Vol 61 (1) ◽  
pp. 28-36
Author(s):  
Zlatan Alagic ◽  
Haris Alagic ◽  
Robert Bujila ◽  
Subhash Srivastava ◽  
Saif Jasim ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Success Rate ◽  
Low Dose ◽  
Quality Parameters ◽  
Ct Guided ◽  
Protocol Group ◽  
Group A ◽  
The Mean ◽  
Group B

Background The use of computed tomography (CT) for image guidance during biopsies is a powerful approach. The method is, however, often associated with a significant level of radiation exposure to the patient and operator. Purpose To investigate if a low-dose protocol for CT-guided musculoskeletal (MSK) biopsies, including a combination of different radiation dose (RD) techniques, is feasible in a clinical setting. Material and Methods Fifty-seven patients underwent CT-guided fine-needle aspiration cytology (FNAC) utilizing the low-dose protocol (group A). A similar number of patients underwent CT-guided FNAC using the reference protocol (group B). Between-group comparisons comprised radiation dose, success rate, image quality parameters, and workflow. Results In group A, the mean total dose-length product (DLP) was 41.2 ± 2.9 mGy*cm, which was statistically significantly lower than of group B (257.4 ± 22.0 mGy*cm), corresponding to a mean dose reduction of 84% ( P<0.001). The mean CTDIvol for the control scans were 1.88 ± 0.09 mGy and 13.16 ± 0.40 mGy for groups A and B, respectively ( P < 0.001). The success rate in group A was 91.2% and 87.9% in group B ( P = 0.56). No negative effect on image-quality parameters, time of FNAC, and number of control scans were found. Conclusion We successfully developed a low-dose protocol for CT-guided MSK biopsies that maintains diagnostic accuracy and image quality at a fraction of the RD compared to the reference biopsy protocol at our clinic.

The Value of Low-dose Prospective Dual-energy Computed Tomography with Iodine Mapping in the Diagnosis of Gastric Cancer

2020 ◽  
Vol 16 (4) ◽  
pp. 433-437
Author(s):  
Lifeng Wang ◽  
Xingxing Jin ◽  
Zhenguo Qiao ◽  
Bin Xu ◽  
Jiaqing Shen
Keyword(s):  
Gastric Cancer ◽  
Computed Tomography ◽  
Image Quality ◽  
Radiation Dose ◽  
Low Dose ◽  
Preoperative Staging ◽  
Control Group ◽  
Imaging Quality ◽  
Group A ◽  
Group B

Objectives: This study investigated the radiation dose and value of prospective dualenergy computed tomography (DECT) in the diagnosis of gastric cancer. Methods: Sixty patients scheduled for computed tomography (CT) for preoperative staging were divided into two groups. Thirty patients (Group A) underwent a single contrast-enhanced abdominal CT acquisition using a dual-source mode (100 kV/140 kV). Weighted average images of the two-kilovolt acquisitions and iodine maps were created. The remaining 30 patients underwent a standard CT scan (Group B). Two observers performed a blinded read of the images for gastric lesions, evaluating the image quality and recording effective dose. Results: During the blinded read, observers found 90% (27/30) of the cancers in both groups. The mean imaging quality scores were 2.1±0.9 for Group A, and 2.3±1.1 for Group B. The effective mean doses were 6.59±0.59 mSv and 25.86±0.44 mSv for Groups A and B, respectively. Compared with the control group (B), the imaging quality in the low-dose group decreased a little, but the radiation dose substantially decreased by 74.6%. Conclusion: The new DECT technique is valuable for examining gastric cancer patients. The dualkV scan mode can substantially reduce radiation dose while preserving good diagnostic image quality.

Abdominal CT with Low Tube Voltage: Preliminary Observations about Radiation Dose, Contrast Enhancement, Image Quality, and Noise

Radiology ◽  
2005 ◽  
Vol 237 (3) ◽  
pp. 945-951 ◽  
Author(s):  
Yoshiharu Nakayama ◽  
Kazuo Awai ◽  
Yoshinori Funama ◽  
Masahiro Hatemura ◽  
Masanori Imuta ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Contrast Enhancement ◽  
Abdominal Ct ◽  
Tube Voltage ◽  
Low Tube Voltage
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