Table of Contents
The new CT technology: what are the
benefits?
The new CT technology
What is the “new technology”?
What is the “new technology”?
How does the patient benefit?
How does the patient benefit?
Axial image quality
Multi-slice scanning
Advantages over single slice
Shorter time ? fewer motion artefacts
Thinner slices ? better z-axis resolution
Thinner slices ? better 3D images
Longer volumes?? more useful scans
What evidence is there of improvements?
Advantages for CT angiography
Advantages for CT angiography
Vessel analysis
Artefacts in multi-slice scanning
Photon starvation artefacts
Methods of image reconstruction
Multi-dimensional adaptive filtering (MAF)
Effects of 3D filtration
Noise reduction using 3D filtration
Artefacts in multi-slice scanning
The cone beam problem
Cone beam artefact
Cone beam effect
Solving the cone beam problem
Effects of using cone beam algorithm
How does the patient benefit?
Improved patient comfort and compliance
Reduced risk of complications
CT Perfusion
Sparing invasive procedures
Cardiac CT with earlier technology
Cardiac CT now
Prospective ECG gating
Retrospective ECG gating
Retrospective ECG gating
Cardiac calcification scoring
CT coronary angiography
Phase-selective reconstruction
How does the patient benefit?
Multi-slice v. single-slice doses
How might doses be higher with multi-slice?
Thin slices: contribution of penumbra
Geometric efficiencies
How might doses be lower?
Dose reduction features
Matching tube current to attenuation
Tube current modulation
ECG-gated mA modulation
Paediatric protocols
Conclusions
|