Table of contents

Helical and Multi-slice Principles

…Requirements for helical CT

Helical CT data collection

Helical / spiral scanning

Helical pitch

Helical image reconstruction

Helical interpolation

360° Linear interpolation

Complementary projections

180° linear interpolation

Advantages of helical scanning

Helical scanning advantages - 3D

Disadvantages of helical scanning

Dual-slice CT

Dual slice capabilities

Multi-slice CT

Multi-slice detectors

Detector switching for slice width selection

Four slice detectors

16 slice detectors

16 slice detector arrays

Multi-slice detector switching

Helical multi-slice: pitch

Pitch in multi-slice

Helical multi-slice interpolation

4-8 slice helical reconstruction

Cone beam artefacts

16 slice helical reconstruction

Tilted reconstruction

3D reconstruction

AMPR, Feldkamp etc

Advantages of MS CT

Scan speed

Z-axis resolution

Isotropic imaging

Larger scan volumes

Uptake of helical and multi-slice CT in UK

Author: Nick Keat

E-mail: nick@impactscan.org

Homepage: http://www.impactscan.org/

ImPACT course presentation index: http://www.impactscan.org/impactcourseslides.htm