Related Experiment Videos
Technical aspects of helical (spiral) CT
1Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA.
Radiologic Clinics of North America
|September 1, 1995
Summary
Optimal helical CT imaging, including CT angiography, requires careful planning of collimation, table feed, and reconstruction intervals. Balancing these parameters maximizes longitudinal resolution while managing tradeoffs like pixel noise and scan coverage for effective 3-D imaging.
Area of Science:
- Medical Imaging Physics
- Radiological Technology
Background:
- Helical computed tomography (CT) and its applications like CT angiography necessitate precise parameter selection for optimal image quality.
- Key parameters include collimation, table feed, and reconstruction interval, each influencing image resolution and noise characteristics.
Purpose of the Study:
- To outline critical prospective planning considerations for helical CT imaging.
- To detail the tradeoffs involved in selecting collimation, table feed, and reconstruction intervals for 3-D imaging applications.
Main Methods:
- Analysis of the impact of collimation settings on pixel noise.
- Evaluation of table feed relative to collimation (pitch) and its effect on slice thickness and scan coverage.
- Determination of appropriate reconstruction intervals based on clinical needs, particularly for multiplanar and 3-D reconstructions.
Main Results:
- Minimizing collimation, table feed, and reconstruction interval generally maximizes longitudinal resolution.
- Decreasing collimation increases pixel noise.
- A table feed up to twice the collimation (pitch of 2:1) is often acceptable with modern CT equipment.
- For 3-D imaging, reconstruction intervals should yield at least two slices per table increment.
Conclusions:
- Strategic adjustment of helical CT parameters is crucial for achieving high-quality 3-D imaging and specialized applications.
- Understanding the interplay between collimation, pitch, and reconstruction interval allows for optimized image acquisition and diagnostic accuracy.