Location

Williamsburg, VA

Start Date

1-1-1986 12:00 AM

Description

The present capability of commercially available computed tomography (CT) systems is limited to spatial resolutions of 0.5–1.0 mm, with mesh sizes up to 1024 × 1024 picture elements. We describe here a new investigation of CT’s application to the special case of an object with annular geometry and limited density range, to obtain spatial resolution of 0.25 mm in fields as large as 1 M in diameter. We take a series of views 0.3° apart around the object of interest. Each of the 1200 views consists of 4096 linear attenuation measurements along parallel rays through the field. The spacing of these rays is 0.25 mm. The views are Fourier-transformed and convolved with an appropriate convolution filter in frequency space. They are then transformed back into physical space and backprojected onto the image plane.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

5A

Chapter

Chapter 4: Systems and Reliability

Section

Systems

Pages

835-842

DOI

10.1007/978-1-4615-7763-8_89

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

High-Spatial-Resolution Computed Tomography for thin Annular Geometries

Williamsburg, VA

The present capability of commercially available computed tomography (CT) systems is limited to spatial resolutions of 0.5–1.0 mm, with mesh sizes up to 1024 × 1024 picture elements. We describe here a new investigation of CT’s application to the special case of an object with annular geometry and limited density range, to obtain spatial resolution of 0.25 mm in fields as large as 1 M in diameter. We take a series of views 0.3° apart around the object of interest. Each of the 1200 views consists of 4096 linear attenuation measurements along parallel rays through the field. The spacing of these rays is 0.25 mm. The views are Fourier-transformed and convolved with an appropriate convolution filter in frequency space. They are then transformed back into physical space and backprojected onto the image plane.