US 8,552,387 B2Granted

Method for determining radiation attenuation by an examination object in a positron emission tomography scanner

AssigneeSiemens Aktiengesellschaft

InventorMatthias Fenchel

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Abstract

In an embodiment, an initial segmentation of an examination object is fixed, wherein an attenuation coefficient is assigned to each segment of the segmentation. Raw radiation data about the examination object arranged in the positron emission tomography scanner is acquired, and a correction factor is determined for each pixel with the aid of an optimization method, in which the probability of the acquired raw radiation data is maximized taking into account the segmentation and the attenuation coefficients assigned to the segments. A statistical parameter of the correction factors is determined for each segment and the segmentation is corrected by subdividing a segment as a function of the statistical parameter determined for the segment. A segment correction factor is determined for each segment from the correction factors assigned to the segment and the attenuation coefficients assigned to the segments are corrected as a function of the segment correction factors.

Claims17

Dependent claims

A method for determining radiation attenuation by an examination object in a positron emission tomography scanner, the method comprising:

fixing an initial segmentation of the examination object, an attenuation coefficient being assigned to each segment of the segmentation and each segment including one or more pixels of the examination object;
automatically acquiring raw radiation data about the examination object with the aid of the positron emission tomography scanner, a positron emission source being arranged in the positron emission tomography scanner;
automatically determining a correction factor for each of the one or more pixels of each segment with the aid of an optimization method, a probability of the acquired raw radiation data being optimized by taking into account the segmentation and the attenuation coefficients assigned to the segments;
automatically determining a statistical parameter of the correction factors for each segment, wherein the statistical parameter of a segment is determined by the correction factors that are assigned to the one or more pixels of each segment;
automatically correcting the segmentation by subdividing each respective segment as a function of the statistical parameter determined for the respective segment;
and
automatically correcting the attenuation coefficients assigned to the segments as a function of the correction factors assigned to the respective segment.

4 more elements

A positron emission tomography system, comprising:

a positron emission tomography scanner, including a positron emission detector to detect radiation emitted by an examination object arranged in the positron emission tomography scanner;
a control unit to actuate the positron emission detector and to receive raw radiation data;
and
an image-calculation unit to reconstruct image data from the raw radiation data,
wherein the positron emission tomography system is embodied
to fix an initial segmentation of the examination object, radiation attenuation being assigned to each segment of the segmentation and each segment comprising one or more pixels of the examination object,
to acquire automatically raw radiation data about the examination object with the aid of the positron emission tomography scanner, including a positron emission source arranged in the positron emission tomography scanner,
to determine automatically a correction factor for each pixel with the aid of an optimization method, a probability of the acquired raw radiation data being optimized by taking into account the segmentation and the attenuation coefficients assigned to the segments,
to determine automatically a statistical parameter of the correction factors for each segment, the statistical parameter of a segment being determined by the correction factors assigned to the one or more pixels of each segment,
to correct automatically the segmentation by subdividing each respective segment as a function of the statistical parameter determined for the respective segment,
to determine automatically a segment correction factor for each segment from the correction factors assigned to the respective segment, and
to correct automatically the attenuation coefficients assigned to the segments as a function of the segment correction factors.

9 more elements

Dependencies are inferred from the claim text.