Assessment of distortion in a three-dimensional rotational angiography system
R R Bridcut, BSc, MSc
1
R J Winder, BSc, MSc
1
A Workman, BSc, MSc
2 and
P Flynn, MRCP, FRCR
3
1 Northern Ireland Regional Medical Physics Agency, Royal Victoria Hospital, Grosvenor Road, Belfast BT12 6BA, 2 Northern Ireland Regional Medical Physics Agency, Forster Green Hospital, 110 Saintfield Road, Belfast BT8 4HD and 3 Department of Neuroradiology, Royal Group of Hospitals, Grosvenor Road, Belfast BT12 6BA, UK
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Figure 1. Improved morphological depiction of an aneurysm (arrow) of the anterior communicating artery and associated blood vessels by two-dimensional visualization (a) compared with three-dimensional visualization (b).
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Figure 2. Phantom constructed to assess three-dimensional (3D) geometrical distortion. 1 mm ball bearings are positioned in a 3D lattice configuration, supported by polycarbonate sheets in a water-filled Perspex cube.
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Figure 3. Visualization of the reconstructed three-dimensional image volume, thresholded to remove Perspex and water, displaying only ball bearings.
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Figure 4. Image intensifier two-dimensional image of the Leeds TO.M1 wire grid test object acquired at a nominal 17 cm field of view.
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Figure 5. Graph showing the relative displacement of a point in space close to the centre of the field of view for 100 projection images, illustrating gantry wobble.
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Copyright © 2002 by the British Institute of Radiology.
