Volumetric Imaging with Ultrasonic Spiral CT1
Haim Azhari, DSc and
Didi Sazbon, MSc
1 From the Department of Biomedical Engineering, Technion, Israel Institute of Technology, Haifa 32000, Israel. Received September 15, 1997; revision requested November 24; final revision received November 20, 1998; accepted January 15, 1999. Supported in part by the Israel Science Foundation (grant Z-953/93), the Technion Vice Provost for Research Fund (J. Tal Equipment and Research Fund 130-304), the Irving and Adele Rosenberg Foundation, and the Israel Cancer Association (grants 960023-B and 972025-B). Address reprint requests to H.A. (e-mail: haim@biomed.technion.ac.il).
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Figure 1. Schematic illustrates A, conventional 3D reconstruction versus B, volumetric spiral reconstruction. A set of parallel cross sections is provided in A, whereas a single data set (volumetric) is obtained in B. Note that small objects located between two consecutive scanned planes may disappear in A.
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Figure 2a. Plasticine spherical target. (a) Conventional 3D scan depicts four sections (slice 1–4) 10 mm apart (schematically illustrated on the left). Only the second section (slice 2) depicts a cross-sectional image of the upper part of the sphere. Note that the sphere would have been undetected with a slight change in section position. (b) Spiral CT scan was obtained with four spirals and 10-mm pitch (schematically illustrated on the left). The four sections (slice 5–8) depict cross sections located between the two dashed lines in the schematic and passing through the sphere. In this case, the spiral reconstruction consists of 16 sections.
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Figure 2b. Plasticine spherical target. (a) Conventional 3D scan depicts four sections (slice 1–4) 10 mm apart (schematically illustrated on the left). Only the second section (slice 2) depicts a cross-sectional image of the upper part of the sphere. Note that the sphere would have been undetected with a slight change in section position. (b) Spiral CT scan was obtained with four spirals and 10-mm pitch (schematically illustrated on the left). The four sections (slice 5–8) depict cross sections located between the two dashed lines in the schematic and passing through the sphere. In this case, the spiral reconstruction consists of 16 sections.
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Figure 3a. Hard-boiled egg phantom. Spiral reconstructions obtained with eight spiral windings and 10-mm pitch depict the following cross-sectional views: (a) axial, (b) longitudinal, and (c) oblique (tilted 35° relative to the axial plane).
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Figure 3b. Hard-boiled egg phantom. Spiral reconstructions obtained with eight spiral windings and 10-mm pitch depict the following cross-sectional views: (a) axial, (b) longitudinal, and (c) oblique (tilted 35° relative to the axial plane).
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Figure 3c. Hard-boiled egg phantom. Spiral reconstructions obtained with eight spiral windings and 10-mm pitch depict the following cross-sectional views: (a) axial, (b) longitudinal, and (c) oblique (tilted 35° relative to the axial plane).
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Figure 4a. Breast biopsy phantom. Spiral reconstructions, obtained with 16 spirals and 5-mm pitch, consist of 128 x 128 x 64 voxels of 1.4 x 1.4 x 1.25 mm. Abnormal tissue targets (arrows) are clearly visible. (a) Coronal cross section 10 (of 64). (b) Axial cross section 56 (of 128). (c) Sagittal cross section 80 (of 128).
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Figure 4b. Breast biopsy phantom. Spiral reconstructions, obtained with 16 spirals and 5-mm pitch, consist of 128 x 128 x 64 voxels of 1.4 x 1.4 x 1.25 mm. Abnormal tissue targets (arrows) are clearly visible. (a) Coronal cross section 10 (of 64). (b) Axial cross section 56 (of 128). (c) Sagittal cross section 80 (of 128).
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Figure 4c. Breast biopsy phantom. Spiral reconstructions, obtained with 16 spirals and 5-mm pitch, consist of 128 x 128 x 64 voxels of 1.4 x 1.4 x 1.25 mm. Abnormal tissue targets (arrows) are clearly visible. (a) Coronal cross section 10 (of 64). (b) Axial cross section 56 (of 128). (c) Sagittal cross section 80 (of 128).
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Figure 5. Breast biopsy phantom. On the 3D computer rendering, the phantom was virtually cut about 10 mm from its base to enable a look inside at its lesions. This type of presentation may provide a better orientation to the physician and may help plan more effective surgical procedures.
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Copyright © 1999 by the Radiological Society of North America.
