Prospective Randomized Trial On RadiaTion Dose Estimates Of CT AngIOgraphy In PatieNts Scanned With A Sequential Scan Protocol

Study Overview
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Brief Summary
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The objective of this study is to compare radiation dose of a standard spiral scan with the a new sequential scan protocol. We hypothesize that the sequential scan protocol is associated with a reduction in dose estimates of at least 20%, while the diagnostic image quality is not inferior. Secondary endpoints of the study include quantitative image quality parameters, diagnostic accuracy for spiral versus sequential studies compared to invasive angiography in patients who underwent subsequent invasive coronary angiography.

Detailed Description
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All patients scheduled for a coronary CT scan are screened for inclusion and exclusion criteria. Patients are included if they have stable sinus rhythm (heart rate <75 bpm for dual source CT and <65 bpm for 64-slice CT). Informed signed consent is obtained from these patients and the CT scan is prepared. After topogram scan and the native scan for Ca-Scoring, patients are randomized in two groups with the use of sealed envelopes. After that contrast-enhanced coronary CT angiography is performed with the standard spiral protocol or with the sequential protocol. The CT examination is evaluated by two experienced investigators on a per-vessel basis and all results and study-related data are collected in a dedicated database. For assessment of image quality, a previously established 4-point score system is used and quantitative image quality parameters are measured. A 30 day follow-up after the CT examination aims to evaluate if patients underwent invasive coronary angiography or were scheduled for a myocardial stress / perfusion test (such as stress-echocardiography, myocardial scintigraphy or stress perfusion imaging by MRI).

Official Title
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Prospective Randomized Trial On RadiaTion Dose Estimates Of CT AngIOgraphy In PatieNts Scanned With A Sequential Scan Protocol

Conditions
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Coronary Disease

Intervention / Treatment
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* Radiation: Spiral image acquisition
* Radiation: sequential image acquisition


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients with an indication for a coronary CT angiography (planned evaluation of the coronary arteries) stable sinus rhythm heart rate < 75 bpm with dual-source CT or < 65 bpm with single-source CT signed informed consent Exclusion Criteria: non-ECG triggered studies non-coronary CTA studies, e.g. bypass graft CTAs, pre- or post EP studies, CABG planning studies

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1<br>Standard spiral CT protocol | Radiation: Spiral image acquisition<br>* standard spiral scan protocol<br>|
| Active Comparator: 2<br>Sequential CT protocol | Radiation: sequential image acquisition<br>* sequential CT scan protocol<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Compared with a helical scan protocol the use of a sequential scan protocol is associated with a comparable diagnostic image quality, while the radiation dose estimates are significantly reduced. |  | 1 month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| impact of the sequential scan protocol on quantitative image quality parameters, e.g. image noise, signal and contrast intensity, signal- and contrast-to-noise-ratios |  | 30 days | 
| diagnostic accuracy (sensitivity, specificity as well as positive and negative predictive values) for studies scanned with helical vs. sequential scan protocol when compared with invasive coronary angiography on a per-vessel based analysis |  | 30 days | 
| frequency of non-diagnostic CTA studies when comparing studies scanned with the helical vs. the sequential scan protocol |  | 30 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Coronary CT angiography, Radiation dose estimates