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Sci—Sat AM(1): Planning — 01: Volumetric 4D Computed Tomography with a 320 Multi‐Slice Scanner
Author(s) -
Bracken J,
Coolens C,
Driscoll B
Publication year - 2010
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.3476201
Subject(s) - scanner , imaging phantom , helical scan , iterative reconstruction , volume (thermodynamics) , image quality , reduction (mathematics) , projection (relational algebra) , nuclear medicine , materials science , computer science , computer vision , physics , algorithm , artificial intelligence , mathematics , medicine , acoustics , geometry , quantum mechanics , magnetic tape , tape recorder , image (mathematics)
The performance of a volumetric 320 multi‐slice CT scanner was evaluated for its ability to generate 4DCT volume data sets compared to conventional, retrospective helical 4DCT for improved treatment planning in radiation therapy. A respiratory motion phantom was imaged with this scanner to acquire measurements of volumes, contrast‐to‐noise ratio, respiratory motion amplitude and breathing rate. The 320‐slice scanner provided the same level of volume measurement accuracy as the conventional helical approach and the contrast‐to‐noise ratio produced by the 320‐slice scanner was slightly improved (by ≈20%) relative to the conventional scans. An order of magnitude reduction in scan time and required x‐ray tube output was achieved when switching from the conventional, helical scan approach to the volumetric approach. For the 320‐slice scanner, using a continuous scanning mode measured breathing amplitude more accurately (by ≈10%) than a periodic, intermittent scan mode (2s sampling period). However, the intermittent volumetric scan mode was more effective at reducing the required tube output and sampling breathing changes over several breathing cycles. Partial projection artifacts were noticeable at slower gantry rotation times (1s) for conventional and volumetric scanning techniques, so this time should be minimized. Volumetric CT can simplify 4DCT volume acquisitions and shorten the time to acquire them, which could lead improvements in beam and internal target volume optimization for radiotherapy treatment planning. The reduction in required scan time and simplified image reconstruction when using a volumetric approach could also lead to improved patient throughput during simulation.