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Method for determining discrete localized blood flow in a large volume of tissue
Assignee: New York University
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Filing: 1973-04-26
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Granted: 1975-06-24
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Expires: 1993-04-26
Abstract
Abstract A method for determining discrete localized blood flow in a large volume of tissue, such as local cerebral emission flow in a discrete radiation emission detection zone of a patient''s brain. The brain is subdivided into a plurality of detection zones, such as 144, by means of a headgear apparatus which defines these detection zones by means of a multiplanar array of an equal number of detectors, each detector having an associated collimator to limit the field of view of the detector. A radioactive gas, such as one having two gamma energy levels, such as Xe133, or a gaseous mixture of two different gamma energy level isotopes, is inhaled by the patient, such as in a closed inhalation-exhalation breathing system, over a predetermined data collection period during which the concentration of the gas in the blood is periodically increased. Determinations of arterial blood radiation concentration and tissue radiation concentration are made during this period, and the local cerebral blood flow is subsequently determined from these determinations. The arterial blood radiation concentration is preferably determined by determining the radiation concentration of the gas in the last part of an exhalation, while the tissue radiation concentration is preferably determined from the radiation emissions quantified by the detector array such as by detecting both gamma energy levels, the field of view of the detector depending on the gamma energy level being detected.
Inventors
- 👤 Myron Youdin
- 👤 June N Barker
- 👤 Theobald Reich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:59
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/68; A61B5/6801; A61B5/6802; A61B5/6803; A61B5/02; A61B5/026; A61B5/0275; A61B5/02755; A61B5/08; A61B5/0813; A61B5/40; A61B5/4058; A61B5/4064; A61B5/41; A61B5/414; A61B5/416; A61B6/00; A61B6/42; A61B6/4208; A61B6/4258; A61B6/50; A61B6/507; G; G01; G01T; G01T1/00; G01T1/29; G01T1/2914; G01T1/2985
Claims Analysis
Total Claims: 63
Claim 1
Independent Claim
227 words
A method for determining a discrete localized blood flow in a preselected radiation emission detection zone of a volume of tissue comprising the steps of a. defining a plurality of radiation emission detection zones for at least a portion of said tissue volume, said plurality of zones including said preselected zone; b. defining a plurality of effective fields of view, each of said plurality of zones being within at least one effective field of view, each of said effective fields of view being defined with respect to an associated predetermined axis of view, each of said effective fields of view including said preselected zone and at least a portion of one or more of said other zones of said plurality of zones; c. providing a source of radiation emission for said blood for causing each detection zone to have an associated quantity of radioisotope concentration and an associated quaNtity of radiation emission dependent on said associated radioisotope concentration; and d. quantifying said associated quantity of radioisotope concentration for said preselected zone by quantifying a resultant radiation emission quantity for each of said effective fields of view, said resultant radiation emission quantities being dependent on said radioisotope concentrations of said preselected zone and said portions of said plurality of zones included within each of said effective fields of view, whereby said discrete localilzed blood flow may be determined.
Claim 2
Independent Claim
227 words
A method for determining a discrete localized blood flow in a preselected radiation emission detection zone of a volume of tissue comprising the steps of a. defining a plurality of radiation emission detection zones for at least a portion of said tissue volume, said plurality of zones including said preselected zone; b. defining a plurality of effective fields of view, each of said plurality of zones being within at least one effective field of view, each of said effective fields of view being defined with respect to an associated predetermined axis of view, each of said effective fields of view including said preselected zone and at least a portion of one or more of said other zones of said plurality of zones; c. providing a source of radiation emission for said blood for causing each detection zone to have an associated quantity of radioisotope concentration and an associated quaNtity of radiation emission dependent on said associated radioisotope concentration; and d. quantifying said associated quantity of radioisotope concentration for said preselected zone by quantifying a resultant radiation emission quantity for each of said effective fields of view, said resultant radiation emission quantities being dependent on said radioisotope concentrations of said preselected zone and said portions of said plurality of zones included within each of said effective fields of view, whereby said discrete localilzed blood flow may be determined.
Claim 3
Dependent Claim
37 words
A method in accordance with claim 1 wherein said detection zone defining step comprises defining a plurality of radiation emission detection zones for substantially all of said tissue volume, said plurality of zones including said preselected zone.
Claim 4
Dependent Claim
99 words
A method in accordance with claim 1 wherein said detection zone defining step further comprises defining said detection zones in at least a quadrant of said tissue volume, said radiation emission providing step comprises providing a source of radiation emission having at least two distinct radiation emission energy levels, said effective field defining step comprises defining a different effective field of view for each of said energy levels, and said quantifying step comprises quantifying said associated quantity of radioisotope concentration for said preselected zone by quantifying a resultant radiation emission quantity for each of said effective fields of view.
Claim 5
Independent Claim
226 words
A method for determining a local cerebral blood flow in a preselected radiation emission detection zone of a brain comprising the steps of a. defining a plurality of cerebral radiation emission detection zones for at least a portion of said brain, said plurality of zones including said preselected zone; b. defining a plurality of effective fields of view, each of said plurality of zones being withhin at least one effective field of view, each of said effective fields of view being defined with respect to an associated predetermined axis of view, each of said effective fields of view including said preselected zone and at least a portion of one or more of said other zones of said plurality of zones; c. providing a source of radiation emission for said cerebral blood for causing each detection zone to have an associated quantity of radioisotope concentration and an associated quantity of radiation emission dependent on said associated radioisotope concentration; and d. quantifying said associated quantity of radioisotope concentration for said preselected zone by quantifying a resultant radiation emission quantity for each of said effective fields of view, said resultant radiation emission quantities being dependent on said radioisotope concentrations of said preselected zone and said portions of said plurality of zones included within each of said effective fields of view, whereby said local cerebral blood flow may be determined.
Claim 6
Independent Claim
226 words
A method for determining a local cerebral blood flow in a preselected radiation emission detection zone of a brain comprising the steps of a. defining a plurality of cerebral radiation emission detection zones for at least a portion of said brain, said plurality of zones including said preselected zone; b. defining a plurality of effective fields of view, each of said plurality of zones being withhin at least one effective field of view, each of said effective fields of view being defined with respect to an associated predetermined axis of view, each of said effective fields of view including said preselected zone and at least a portion of one or more of said other zones of said plurality of zones; c. providing a source of radiation emission for said cerebral blood for causing each detection zone to have an associated quantity of radioisotope concentration and an associated quantity of radiation emission dependent on said associated radioisotope concentration; and d. quantifying said associated quantity of radioisotope concentration for said preselected zone by quantifying a resultant radiation emission quantity for each of said effective fields of view, said resultant radiation emission quantities being dependent on said radioisotope concentrations of said preselected zone and said portions of said plurality of zones included within each of said effective fields of view, whereby said local cerebral blood flow may be determined.
Claim 7
Dependent Claim
37 words
A method in accordance with claim 4 wherein said detection zone defining step comprises defining a plurality of cerebral radiation emission detection zones for substantially all of said brain, said plurality of zones including said preselected zone.
Claim 8
Dependent Claim
71 words
A method in accordance with claim 4 wherein the step of providing a source of radiation emission for said cerebral blood includes the step of dissolving a concentration of a radioactive substance in said cerebral blood over a predetermined period of time, said radioactive substance having an associated radiation emission, said zone associated quantities of radiation emission and radioisotope concentration being dependent upon said substance associated radiation emission and radioisotope concentration.
Claim 9
Dependent Claim
34 words
A method in accordance with claim 6 wherein the dissolving step includes the additional step of dissolving an increasing concentration of said radioactive substance in said cerebral blood over said predetermined period of time.
Claim 10
Dependent Claim
33 words
A method in accordance with claim 7 wherein the step Of quantifying said associated quantities of radiation emission includes the step of quantifying said associated quantities of radiation emission during said predetermined time.
Claim 11
Dependent Claim
32 words
A method in accordance with claim 6 wherein said dissolving step includes the additional step of inhaling a radioactive gas in a closed inhalation-exhalation breathing system over said predetermined period of time.
Claim 12
Dependent Claim
38 words
A method in accordance with claim 9 wherein said additional inhalation step includes the further step of injecting a predetermined quantity of said gas into said closed system substantially at the beginning of an inhalation by said patient.
Claim 13
Dependent Claim
58 words
A method in accordance with claim 10 wherein said further injecting step includes a still further step of injecting a predetermined quantity of said gas into said closed system substantially at the beginning of each inhalation by said patient during said period of time whereby said cerebral blood gas concentration is increased over said predetermined period of time.
Claim 14
Dependent Claim
37 words
A method in accordance with claim 10 wherein said further injecting step includes the still further step of mixing said injected gas with an immediately preceeding exhalation of said patient prior to said inhalation by said patient.
Claim 15
Dependent Claim
29 words
A method in accordance with claim 9 wherein said additional inhaling step includes the further step of inhaling a radioactive gas which is substantially inert to said cerebral blood.
Claim 16
Dependent Claim
34 words
A method in accordance with claim 9 wherein said inhaling step includes the further step of inhaling a radioactive gas having an associated gamma radiation emission, said gamma emission being said quantified radiation emission.
Claim 17
Dependent Claim
23 words
A method in accordance with claim 9 wherein said additional inhaling step includes the further step of inhaling Xenon133 as said radioactive gas.
Claim 18
Dependent Claim
23 words
A method in accordance with claim 9 wherein said additional inhaling step includes the further step of inhaling Kryton85 as said radioactive gas.
Claim 19
Dependent Claim
37 words
A method in accordance with claim 4 wherein said zone defining step includes the additional step of defining at least 144 radiation emission detection zones in said plurality of zones for defining substantially all of said brain.
Claim 20
Dependent Claim
30 words
A method in accordance with claim 4 wherein said zone defining step includes the additional step of defining a multiplanar array of said detection zones in said plurality of zones.
Claim 21
Dependent Claim
42 words
A method in accordance with claim 4 wherein said zone defining step includes the further step of defining a reproducible basal plane for said brain as a reference plane, said plurality of detection zones being defined with respect to said basal plane.
Claim 22
Dependent Claim
30 words
A method in accordance with claim 19 wherein said further zone defining step includes the still further step of defining the glabellar-sellar plane of the brain as said basal plane.
Claim 23
Dependent Claim
60 words
A method in accordance with claim 20 wherein said still further zone defining step includes the additional step of defining the mid-saggital plane of the brain as a second reference plane for said brain, said second reference plane being substantially perpendicular to said basal plane, said plurality of detection zones being further defined with respect to said second reference plane.
Claim 24
Dependent Claim
60 words
A method in accordance with claim 21 wherein said still further zone defining step includes the still additional step of defining a third reference plane for said brain substantially perpendicular to said basal plane and said second reference plane, and tangent to the forehead, said plurality of detection zones being still further defined with respect to said third reference plane.
Claim 25
Dependent Claim
30 words
A method in accordance with claim 21 wherein said reference plane is defined as a zero reference plane, said detection zones being defined with respect to said zero reference plane.
Claim 26
Dependent Claim
40 words
A method in accordance with claim 23 wherein said zone defining step includes the step of defining said detection zones by a multiplanar array of radiation emission detection Means arrayed about said brain with respect to said zero reference plane.
Claim 27
Dependent Claim
21 words
A method in accordance with claim 24 wherein each of said detection zones is defined as being of substantially equal dimension.
Claim 28
Dependent Claim
30 words
A method in accordance with claim 25 wherein said multiplanar array is a substantially rectangular multiplanar array defining at least 144 detection zones for defining substantially all of said brain.
Claim 29
Dependent Claim
61 words
A method in accordance with claim 4 wherein said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantities for an associated one of said effective fields of view by utilizing an associated detection means including a detector, said associated resultant radiation emission quantity being quantified in accordance with the expression
Claim 30
Dependent Claim
62 words
A method in accordance with claim 27 wherein said still further quantifying step includes the additional step of quantifying each of said resultant quantities of radiation emission in accordance with said expression so as to provide a plurality of simultaneous equations in which at least one equation is provided for each respective zone included within said plurality of effective fields of view.
Claim 31
Dependent Claim
38 words
A method in accordance with claim 28 wherein said quantifying step includes the still further step of processing said simultaneous equations in a data processing means to provide a tissue radiation concentration characteristic for said preselected detection zone.
Claim 32
Dependent Claim
100 words
A method in accordance with claim 4 wherein said method includes the additional step of performing step (d) to provide a first tissue radioisotope concentration as said associated radioisotOpe concentration for said preselected detection zone and, (e) thereafter repeating step (d) to provide a second tissue radioisotope concentration as said associated radioisotope concentration for said preselected detection zone so as to provide a tissue radioisotope concentration characteristic for said preselected detection zone which is an indication of a rate of change in said tissue radioisotope concentration for said preselected detection zone, said local cerebral blood flow determination being dependent thereon.
Claim 33
Dependent Claim
64 words
A method in accordance with claim 6 wherein said dissolving step includes the additional step of inhaling a radioactive gas over said predetermined time; and said method includes the additional step of (f) quantifying a radioisotope concentration of said radioactive gas in arterial cerebral blood during said predetermined time, said local cerebral blood flow determination being dependent on said arterial blood gas radioisotope concentration.
Claim 34
Dependent Claim
48 words
A method in accordance with claim 31 wherein said gas radioisotope concentration quantifying step includes the further step of quantifying said gas radioisotope concentration in the last part of an exhalation of said patient during said predetermined time, so as to provide an arterial blood radioisotope concentration characteristic.
Claim 35
Dependent Claim
78 words
A method in accordance with claim 32 wherein said further gas radioisotope concentration quantifying step includes the still further step of quantifying said gas radioisotope concentration in the last part of each exhalation of said patient during said predetermined time so as to provide an arterial blood radioisotope concentration characteristic which is an indication of a rate of change in said arterial blood concentration, said local cerebral blood flow determination being dependent on said arterial blood concentration characteristic.
Claim 36
Dependent Claim
43 words
A method in accordance with claim 32 wherein said further gas radioisotope concentration quantifying step includes the still further step of end-tidal sampling said exhalation in cooperative relation with said quantifying of said associated quantity of radioisotope concentration for said preselected detection zone.
Claim 37
Dependent Claim
71 words
A method in accordance with claim 6 wherein said dissolving step includes the additional step of inhaling a radioactive gas over said predetermined time; and said method includes the further step of quantifying the gas concentration of carbon dioxide in the last part of an exhalation of said patient during at least a portion of said predetermined time, said local cerebral blood flow determination being dependent on said carbon dioxide concentration.
Claim 38
Dependent Claim
44 words
A method in accordance with claim 35 wherein said further gas concentration quantifying step includes the still further step of quantifying the gas concentration of oxygen in said exhalation last part, said local cerebral blood flow determination being further dependent on said oxygen concentration.
Claim 39
Dependent Claim
69 words
A method in accordance with claim 6 wherein said dissolving step includes the additional step of inhaling a radioactive gas over said predetermined time; and said method includes the further step of quantifying the gas concentration of oxygen in the last part of an exhalation of said patient during at least a portion of said predetermined time, said local cerebral blood flow determination being dependent on said oxygen concentration.
Claim 40
Dependent Claim
74 words
A method in accordance with claim 4 wherein said associated radioisotope concentration is a tissue radioisotope concentration and said method includes the additional step of repeating step (d) at 10 second intervals over a period of a minute so as to provide a tissue radioisotope concentration characteristic which is an indication of rate of change in said tissue radioisotope concentration, said local cerebral blood flow determination being dependent on said tissue radioisotope concentration characteristic.
Claim 41
Dependent Claim
116 words
A method in accordance with claim 38 wherein said providing step includes the further step of providing saiD source of radiation emission by dissolving a concentration of a radioactive gas in said blood by inhalation of said gas in a closed inhalation-exhalation system over said one minute period, and said method includes the additional step of quantifying a radioisotope concentration of said gas in the last part of an exhalation of said patient at said ten second intervals so as to provide an arterial blood radioisotope concentration characteristic which is an indication of rate of change in said arterial blood concentration, said local cerebral blood flow determination being further dependent on said arterial blood concentration characteristic.
Claim 42
Dependent Claim
94 words
A method in accordance with claim 4 wherein said quantifying step includes the step of providing a tissue radioisotope concentration quantity as said associated radioisotope concentration for said preselected detection zone in accordance with said quantified resultant radiation emission quantities; said radiation emission source providing step includes the step of dissolving a radioactive substance in said blood by inhalation of a radioactive gas; and said method includes the additional steps of providing an arterial blood radioisotope concentration quantity for said dissolved gas, and determining said local cerebral blood flow in accordance with the expression
Claim 43
Dependent Claim
26 words
A method in accordance with claim 6 wherein said dissolving step includes the additional step of inhaling a radioactive gas over said predetermined period of time.
Claim 44
Dependent Claim
37 words
A method in accordance with claim 4 wherein said detection zone defining step comprises defining a plurality of radiation emission detection zones for sustantially all of said brain volume, said plurality of zones including said preselected zone.
Claim 45
Dependent Claim
69 words
A method in accordance with claim 42 wherein said detection zone defining step further comprises defining said detection zones in a plurality of quadrants of said brain volume and said quantifying step further comprises quantifying said associated quantity of radioisotope concentration for said quadrants by independently quantifying a resultant radiation emission quantity for each of said effective fields of view in said one quadrant apart from said other quadrants.
Claim 46
Dependent Claim
140 words
A method in accordance with claim 42 wherein said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantifying step includes the further step off quantifying at least one of said resultant radiation emission quantities for an associated one of said effective fields of view by utilizing an associated detection means including a detector, said associated resultant radiation emission quantity being quantified at least in accordance with the expressions QG4 mI4+nI13 QC1 mL1+nI4 QF1 pI1+qI4+gI10+rI13 QC10 mI10+nI13 for a typical quadrant as illustrated in FIGS. 9A-9E, where Qsubscript represents the detected resultant radiation emission resulting from the contributions of all the detection zones within the effective field of view of an associated Q detector illustrated in FIGS. 9A-9E, Izone represents the radiation concentration of radioisotope contained within a given zone,
Claim 47
Dependent Claim
142 words
A method in accordance with claim 42 wherein said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantities for an associated one of said effective fields of view by utilizing an associated detection means including a detector, said associated resultant radiation emission quantity being quantified at least in accordance with the expressions QG2 mI2+nI11 QG3 mI3+nI12 QA12 mI12+nI11 QH3 pI3+qI2+qI12+rI11 for a typical quadrant as illustrated in FIGS. 10A-10E, where Q subscript represents the detected resultant radiation emission resulting from the contributions of all the detection zones within the effective field of view of an associated Q detector illustrated in FIGS. 10A-10E, I zone represents the radiataion concentration of radioisotope contained within a given zone,
Claim 48
Dependent Claim
142 words
A method in accordance with claim 42 wherein said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantities for an associated one of said effective fields of view by utilizing an associated detection means including a detector, said associated resultant radiation emission quantity being quantified at least in accordance with the expressions QG8 mI8+nI17 QG9 mI9+nI18 QA18 mI18+nI17 QH9 pI9+qI8+qI18+rI17 for a typical quadrant as illustrated in FIGS. 11A-11E, where Q subscript represents the detected resultant radiation emission resulting from the contributions of all the detection zones within the effective field of view of an associted Q detector illustrated in FIGS. 11A-11E, I zone represents the radiation concentration of radioisotope contained within a given zone,
Claim 49
Dependent Claim
142 words
A method in accordance with claim 42 wherein said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantities for an associated one of said effective fields of view by utilizing an associated detection means including a detector, said associated resultant radiation emission quantity being quantified at least in accordance with the expressions QG5 mI5+nI14 QG6 mI6+nI15 QA15 mI15+nI14 QH6 pI6+qI5+qI15+rI14 for a typical quadrant as illustrated in FIGS. 12A-12D, where Q subscript represents the detected resultant radiation emission resulting from the contributions of all the detection zones within the effective field of view of an associated Q detector illustrated in FIGS. 12A-12D, I zone represents the radiation concentration of radioisotope contained within a given zone,
Claim 50
Dependent Claim
142 words
A method in accordance with claim 42 wherein said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantities for an associated one of said effective fields of view by utilizing an associated detection means including a detector, said associated resultant radiation emission quantity being quantified at least in accordance with the expressions QA24 mI24+nI23 QAz1 mI21+nI20 QB21 pI21+qI20+qI24+rI23 QC20 mI20+nI23 for a typical quadrant as illustrated in FIGS. 13A-13E, where Q subscript represents the detected resultant radiation emission resulting from the contributions of all the detection zones within the effective field of view of an associated Q detector illustrated in FIGS. 13A-13E, I zone represents the radiation concentration of radioisotope contained within a given zone,
Claim 51
Dependent Claim
142 words
A method in accordance with claim 42 wherein said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantities for an associated one of said effective fields of view by utilizing an associated detection means including a detector, said associated resultant radiation emission quantity being quantified at least in accordance with the expressions QA33 mI33+nI32 QA30 mI30+nI29 QB30 pI30+qI29+qI33+rI32 QC29 mI29+nI32 for a typical quadrant as illustrated in FIGS. 14A-14D, where Q subscript represents the detected resultant radiation emission resulting from the contributions of all the detection zones within the effective field of view of an associated Q detector illustrated in FIGS. 14A-14D, I zone represents the radiation concentration of radioisotope contained within a given zone,
Claim 52
Dependent Claim
87 words
In a method for determining cerebral blood flow in a patient from the dissolving of a concentration of a radioactive gas in said blood by the inhalation of said gas in a closed inhalation-exhalation breathing system over a predetermined period of time, the improvement comprising the step of injecting a predetermined quantity of said gas into said closed system substantially at the beginning of an inhalation of a tidal volume by said patient so as to increase said blood gas concentration during said predetermined period of time.
Claim 53
Dependent Claim
87 words
In a method for determining cerebral blood flow in a patient from the dissolving of a concentration of a radioactive gas in said blood by the inhalation of said gas in a closed inhalation-exhalation breathing system over a predetermined period of time, the improvement comprising the step of injecting a predetermined quantity of said gas into said closed system substantially at the beginning of an inhalation of a tidal volume by said patient so as to increase said blood gas concentration during said predetermined period of time.
Claim 54
Dependent Claim
60 words
A method in accordance with claim 50 wherein said injection step includes the step of injecting a predetermined quantity of said gas into said closed system substantially at the beginning of each inhalation of a tidal volume by said patient during said predetermined period of time whereby said cerebral blood gas concentration is increased over said predetermined period of time.
Claim 55
Dependent Claim
39 words
A method in accordance with claim 51 wherein said injecting step includes the additional step of mixing said injected gas with an immediately preceeding exhalation of a tidal volume by said patient prior to said inhalation by said patient.
Claim 56
Dependent Claim
107 words
In a method for determining cerebral blood flow in a Patient from the dissolving of a concentration of a radioactive gas in said blood by the inhalation of said gas over a predetermined period of time so as to provide a good gas radioisotope concentration, the improvement comprising the step of quantifying said blood gas radioisotope concentration in the end tidal volume part of an exhalation of said patient during said predetermined time so as to provide an arterial blood concentration characteristic, the arterial blood being in concentration equilibrium with said radio active gas contained in the patient lung alveolar during said end tidal volume exhalation part.
Claim 57
Dependent Claim
107 words
In a method for determining cerebral blood flow in a Patient from the dissolving of a concentration of a radioactive gas in said blood by the inhalation of said gas over a predetermined period of time so as to provide a good gas radioisotope concentration, the improvement comprising the step of quantifying said blood gas radioisotope concentration in the end tidal volume part of an exhalation of said patient during said predetermined time so as to provide an arterial blood concentration characteristic, the arterial blood being in concentration equilibrium with said radio active gas contained in the patient lung alveolar during said end tidal volume exhalation part.
Claim 58
Dependent Claim
78 words
A method in accordance with claim 53 wherein said gas radioisotope concentration quantifying step includes the further step of quantifying said gas radioisotope concentration in the end tidal volume part of each exhalation of said patient during said predetermined time so as to provide an arterial blood radioisotope concentration characteristic which is an indication of a rate of change in said arterial blood concentration, said local cerebral blood flow determination being dependent on said arterial blood concentration characteristic.
Claim 59
Dependent Claim
32 words
A method in accordance with claim 53 wherein said gas radiation quantifying step includes the further step of end-tidal sampling said exhalation so as to provide said exhalation part to be quantified.
Claim 60
Dependent Claim
146 words
A method in accordance with claim 42 wherein said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantities for an associated one of said effective fields of view by utilizing an associated detection means including a detector, said associated resultant radiation emission quantity being quantified at least in accordance with the expressions PA9 aI9+bI8+cI7 PA27 aI27+bI26+cI25 for a typical quadrant as illustrated in FIGS. 15A-15C and 16A and 16B, where P subscript represents the detected resultant radiation emission resulting from the contributions of all the detection zones within the effective field of view of an associated P detector illustrated in FIGS. 15A-15C and 16A and 16B, I zone represents the radiation concentration of radioisotope contained with a given zone,
Claim 61
Dependent Claim
136 words
A method in accordance with claim 42 wherein said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantities for an associated one of said effective fields of view by utilizing an associated detection means including a detector, said associated resultant radiation emission quantity being quantified at least in accordance with the expressions PC21 aI21+bI24+cI27 for a typical quadrant as illustrated in FIGS. 17A-17C, where P sUbscript represents the detected resultant radiation emission resulting from the contributions of all the detection zones within the effective field of view of an associated P detector illustrated in FIGS. 17A-17C, I zone represents the radiation concentration of radioisotope contained within a given zone,
Claim 62
Dependent Claim
158 words
A method in accordance with claim 42 wherein said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantities for an associated one of said effective fields of view by utilizing an associated detection means including a detector, said associated resultant radiation emission quantity being quantified at least in accordance with the expressions PB12 dI12+eI11+eI15+fI14+gI13+gI17+hI16 QC19 mI19+nI22 PA36 aI36+bI35+cI34 QB29 kI30+pI29+qI28+qI32+rI31 for a typical quadrant as illustrated in FIGS. 18A, 18B, 19A, 19B and 20A-20C, where P subscript and Q subscript represent the detected resultant radiation emission resulting from the contributions of all the detection zones within the effective field of view of an associated P and Q detector, respectively, illustrated in FIGS. 18A, 18B, 19A, 19B and 20A-20C, I zone represents the radiation concentration of radioisotope contained within a given zone,
Claim 63
Dependent Claim
162 words
A method in accordance with claim 42 wherein said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantifying step includes the further step of quantifying at least one of said resultant radiation emission quantities for an associated one of said effective fields of view by utilizing an associated detection means including a detector, said associated resultant radiation emission quantity being quantified at least in accordance with the expressions PG1 aI1+bI10+cI19 PG7 aI7+bI16+cI25 QC28 mI28+nI31 PF11 kI2+dI11+eI14+eI20+fI23+gI26+gI32+hI35 PF12 kI3+dI12+eI15+eI21+fI24+gI27+gI33+hI36 for a typical quadrant as illustrated in FIGS. 21A, 21B, 22A, 22B, 23A and 23B, where P subscript and Q subscript represent the detected resultant radiation emission resulting from the contributions of all the detection zones within the effective field of view of an associated P and Q detector, respectively, illustrated in FIGS. 21A, 21B, 22A, 22B, 23A and 23B, I zone represents the radiation concentration of radioisotope contained within a given zone,
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| 7.5 Years (Year 8) | 1982-06-23 | 1982-12-23 | 1983-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-23 | 1986-12-23 | 1987-06-24 | $7700.00 | Window Closed / Lapsed |