US3784820A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tomographic scanning process
Assignee: Case Western Reserve University
•
Filing: 1971-06-25
•
Granted: 1974-01-08
•
Expires: 1991-06-25
Abstract
Abstract A radioisotope device having a collimator delimits radiation from a source. A scintillation crystal having a rectangular cross-section and a generally elongated shape receives radiation after it passes through the collimator and changes it to visible light at each point by a process known as scintillation. Photomultiplier tubes at each end of the scintillation crystal convert the light to electrical pulses. The amplitudes of electrical pulses are converted to logarithms of the amplitudes and summed. A pulse height selector chooses only the sums of those logarithms desired for observation. The logarithms of the amplitudes are also subtracted to find the location of the scintillation in the scintillation crystal. Means are also provided for moving the source of radiation relative to the collimator. A recording means stores information concerning the relative positions of the source and the collimator during the time radiation is received. Information from a plurality of scans allows a determination of a pattern of the radiation at different depths and areas within the source. It is also possible to use a plurality of collimators and scintillation crystals and a single scan to determine radiation patterns at multiple depths within the source.
Inventors
- 👤 F Miraldi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:15
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/16; G01T1/161; G01T1/164; G01T1/1641; G01T1/1642; G01T1/29; G01T1/2914; G01T1/2985; A; A61; A61B; A61B6/00; A61B6/02; A61B6/03; A61B6/037
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
170 words
The process of tomographic scanning with a detector having a linearly focused collimator transmitting radiation to a scintillation crystal and at least one photomultiplier tube to determine patterns of radioactivity from a source having a plane of interest comprising: making a first scan at a first angle from the plane of interest of the source while sensing at each position a line of radiation emanating from different depths and areas within the source; detecting an area of radiation as the linearly focused collimator makes the first scan; recording information concerning the first scan; making a second scan at a second angle from the plane of interest of the source while sensing at each position a line of radiation emanating from different depths and areas within the source; detecting an area of radiation as the linearly focused collimator makes the second scan; recording information concerning the second scan; electronically combining the information from the first and second scans to determine patterns of radiation at different depths and areas within the source.
Claim 2
Dependent Claim
170 words
The process of tomographic scanning with a detector having a linearly focused collimator transmitting radiation to a scintillation crystal and at least one photomultiplier tube to determine patterns of radioactivity from a source having a plane of interest comprising: making a first scan at a first angle from the plane of interest of the source while sensing at each position a line of radiation emanating from different depths and areas within the source; detecting an area of radiation as the linearly focused collimator makes the first scan; recording information concerning the first scan; making a second scan at a second angle from the plane of interest of the source while sensing at each position a line of radiation emanating from different depths and areas within the source; detecting an area of radiation as the linearly focused collimator makes the second scan; recording information concerning the second scan; electronically combining the information from the first and second scans to determine patterns of radiation at different depths and areas within the source.
Claim 3
Dependent Claim
23 words
The process of claim 1 wherein the radiation is sensed along a wedge-shaped channel through the source for each position during the scan.
Claim 4
Dependent Claim
55 words
The process of claim 2 wherein radiation is sensed at an angle between 30* and 60* from the plane of interest during the first scan and from an angle between 30* and 60* from plane of interest during the second scan but the angle of sensing being in a different direction from the first scan.
Claim 5
Dependent Claim
24 words
The process of claim 3 wherein radiation is sensed during the first scan of substantially 45* and during the second scan of substantially 45*.
Claim 6
Dependent Claim
38 words
The process of claim 2 wherein the information recorded during the scans includes the relative position at which the radiation is sensed relative to the source and the amount of radiation sensed by the detector at that location.
Claim 7
Dependent Claim
125 words
The process of tomographic scanning with a detector having dual linearly focused collimators transmitting radiation to dual scintillation crystals and at least two photomultiplier tubes to determine patterns of radioactivity from a source having a plane of interest comprising: making a scan relative to the source while sensing from a first and second angle from the plane of interest lines of radiation emanating from different areas and depths within the source; detecting a first and second area of radiation during the scan; recording information concerning the scan including the radiation sensed from the different directions and information relating to the relative positions at which the radiation is sensed; electronically combining the information to determine patterns of radiation at different depths and areas in the source.
Claim 8
Dependent Claim
125 words
The process of tomographic scanning with a detector having dual linearly focused collimators transmitting radiation to dual scintillation crystals and at least two photomultiplier tubes to determine patterns of radioactivity from a source having a plane of interest comprising: making a scan relative to the source while sensing from a first and second angle from the plane of interest lines of radiation emanating from different areas and depths within the source; detecting a first and second area of radiation during the scan; recording information concerning the scan including the radiation sensed from the different directions and information relating to the relative positions at which the radiation is sensed; electronically combining the information to determine patterns of radiation at different depths and areas in the source.
Claim 9
Dependent Claim
28 words
The process of claim 6 wherein the radiation is sensed along a wedge-shaped channel through the source for each direction of sensing and each point during the scan.
Claim 10
Dependent Claim
14 words
The process of claim 7 wherein fields of view are relatively well defined channels.
Claim 11
Dependent Claim
25 words
The process of claim 8 wherein the radiation is sensed at an angle of between 30* and 60* from a chosen plane in the source.
Claim 12
Dependent Claim
17 words
The process of claim 9 wherein the radiation is sensed at 45* from the plane of interest.
References Cited (Backward Citations)
US3432660A
Cited
US3631244A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-07 | 1977-07-09 | 1978-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-07 | 1981-07-09 | 1982-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-07 | 1985-07-09 | 1986-01-08 | $7700.00 | Window Closed / Lapsed |