Method of imaging by SPECT
First Claim
1. A method of imaging a target organ in a patient by SPECT, by using a gamma camera having a detector/collimator combination including a gamma detector provided with a fan-beam collimator, comprising:
- focusing the collimator to a focal line parallel to the patient'"'"'s body length;
acquiring planar images by relative movement between the gamma camera and the patient'"'"'s body along at least on linear path in a direction perpendicular to the patient'"'"'s body length so that the collimator focal line traverses said target organ; and
computer reconstructing the distribution of the radioactivity inside the patient'"'"'s body from the acquired planar images by using reconstruction algorithms.
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Abstract
A method of imaging a target organ in a patient by SPECT, by using a gamma camera having a gamma detector provided with a fan-beam collimator (2), focusing to a focal line parallel to the patient'"'"'s body length, and by computer reconstructing the distribution of the radioactivity inside the patient'"'"'s body from the acquired planar images by using certain reconstruction algorithms. The images are acquired along at least one linear orbit performed in a direction perpendicular to the patient'"'"'s body, and the collimator focal line is made to travel throughout said target organ during the acquisition. The invention further relates to an equipment for performing this method.
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Citations
21 Claims
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1. A method of imaging a target organ in a patient by SPECT, by using a gamma camera having a detector/collimator combination including a gamma detector provided with a fan-beam collimator, comprising:
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focusing the collimator to a focal line parallel to the patient'"'"'s body length;
acquiring planar images by relative movement between the gamma camera and the patient'"'"'s body along at least on linear path in a direction perpendicular to the patient'"'"'s body length so that the collimator focal line traverses said target organ; and
computer reconstructing the distribution of the radioactivity inside the patient'"'"'s body from the acquired planar images by using reconstruction algorithms. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
where x, y and z are the orthogonal coordinates along the horizontal transverse direction, the vertical transverse direction and the longitudinal direction, respectively;
Pα
(V, r, z) are the planar images pixels values, where r is the coordinate along the transverse direction of the detector and V is the detector position along the linear orbit a;
f is the fan-beam collimator focal length; and
Uα
is the shift length of the fan-beam collimator focal line in the linear orbit a versus the origin of the axis coordinates (x=0, y=0).
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10. Apparatus for imaging a target organ in a patient by SPECT, comprising:
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at least one gamma camera having at least one detector/collimator combination including a gamma detector and a fan-beam collimator fixed to the gamma detector, a bed for a patient to be examined and having a bed length;
means for defining collimator positions located respectively at the corners of a rectangle normal to the bed length to surround the bed, and including a first position over the bed, a second position under the bed, a third position on one side of the bed, and a fourth position on the side of the bed opposite the third position, the at least one collimator being positionable at all of the first, second, third, and fourth positions, and focusing to a focal line parallel to the bed length;
means for positioning the bed at such a distance from the collimator positions, that the collimator focal line is inside the patient'"'"'s body on the bed in each of the collimator positions; and
means for moving the bed in two perpendicular directions, both transverse to the bed length, to effect a horizontal movement at the first and second positions of said at least one collimator and a vertical movement at the third and fourth positions. - View Dependent Claims (11, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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12. Apparatus for imaging a target organ in a patient by SPECT, comprising:
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at least one gamma camera having at least one detector/collimator combination including a gamma detector and a fan-beam collimator fixed to the gamma detector, a bed for a patient to be examined and having a bed surface and a bed length;
collimator positions located respectively at the corners of a rectangle normal to the bed length to surround the bed, and including a first position over the bed, a second position under the bed, a third position on one side of the bed, and a fourth position on the side of the bed opposite the third position;
the at least one collimator being positionable at all of the first, second, third, and fourth positions, and focusing to a focal line parallel to the bed length;
means for positioning the bed at such a distance from the collimator positions, that the collimator focal line is inside the patient'"'"'s body on the bed in each of the collimator positions; and
means for moving the at least one collimator in two perpendicular directions, both transverse to the bed length, to effect movement parallel to the bed surface at the first or second positions of said at least one collimator and movement perpendicular to the bed surface at the third and fourth positions.
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Specification