Zhiqiang Dr Hu

US Patent:

7718954, May 18, 2010

Filed:

Jan 25, 2007

Appl. No.:

11/627104

Inventors:

Wenli Wang - Aurora OH, US
Thomas Laurence - North Royalton OH, US
Zhiqiang Hu - Twinsburg OH, US

Assignee:

Koninklijke Philips Electronics N.V. - Eindhoven

International Classification:

G01T 1/16

US Classification:

2502521

Abstract:

A method and apparatus for calibrating a PET scanner is provided. First phantom sinogram data is acquired from a scan of a solid cylinder phantom within a PET scanner imaging FOV; second phantom sinogram data is acquired from a scan of a second solid plane or scanning line phantom within the PET scanner imaging FOV; and a PET scanner detector component scanner efficiency normalization is determined from at least one of the first and second sinogram data. In one aspect a crystal determining efficiency factor is determined as a function of phantom sinogram data without a solid angle correction, and a detector geometry factor is determined as a function of the crystal efficiency factor and phantom sinogram data. In one aspect a smoothed crystal efficiency normalization factor is determined from a noisy crystal efficiency factor through an iterative smoothing technique.

US Patent:

8073109, Dec 6, 2011

Filed:

Sep 14, 2006

Appl. No.:

12/088090

Inventors:

Daniel Gagnon - Twinsburg OH, US
Wenli Wang - Aurora OH, US
Zhiqiang Hu - Highland Heights OH, US

Assignee:

Koninklijke Philips Electronics N.V. - Eindhoven

International Classification:

G06K 9/00

US Classification:

378131, 25036302, 25036304

Abstract:

A method and system for use in positron emission tomography, wherein a first processor element () is configured to reconstruct a plurality of positron annihilation events detected during a positron emission tomography scan using a list-based reconstruction technique to generate first volumetric data. A second reconstructor () is configured to reconstruct the plurality of events using a second reconstruction technique to generate second volumetric data for determining an error correction (), the error correction applied to the first volumetric data to generate corrected volumetric data for generating a human-readable image (). In one embodiment a multiplicative error correction is performed on the plurality of events, the first processor element () reconstructing the corrected plurality of events; and the second volumetric data error correction comprises an additive error correction.

US Patent:

8406495, Mar 26, 2013

Filed:

Sep 9, 2009

Appl. No.:

13/062222

Inventors:

Daniel Gagnon - Twinsburg OH, US
Zhiqiang Hu - Twinsburg OH, US

Assignee:

Koninklijke Philips Electronics N.V. - Eindhoven

International Classification:

G06K 9/00

US Classification:

382128, 378 4

Abstract:

When correcting attenuation in a nuclear image (e. g. , PET or SPECT), an MR-based attenuation correction (AC) map () is generated using MR image data () of a subject (). The subject () is then placed in a nuclear imaging device with a radioactive point or line source (′) from which transmission data is measured as the patient is imaged. In order to resolve ambiguity between air voxels and bone voxels in the MR-based AC map (), estimated transmission data () is generated from the AC map and compared to the measured transmission data () from the point or line source. An error is iteratively calculated for the estimated and measured transmission data, and attenuation values of the AC map () are refined to minimize the error. The refined AC map () is used to correct attenuation in collected nuclear data () which is reconstructed into an attenuation corrected image () of the patient.

US Patent:

8488849, Jul 16, 2013

Filed:

Feb 5, 2007

Appl. No.:

12/279848

Inventors:

Zhiqiang Hu - Twinsburg OH, US
Wenli Wang - Aurora OH, US
Daniel Gagnon - Twinsburg OH, US

Assignee:

Koninklijke Philips Electronics N.V. - Eindhoven

International Classification:

G06K 9/00

US Classification:

382128

Abstract:

Methods, systems and apparatuses for processing data associated with nuclear medical imaging techniques are provided. Data is ordered in LUT's and memory structures. Articles of manufacture are provided for causing computers to carry out aspects of the invention. Data elements are ordered into a plurality of ordered data groups according to a spatial index order, and fetched and processed in the spatial index order. The data elements include sensitivity matrix elements, PET annihilation event data, and system and image matrix elements, the data grouped in orders corresponding to their processing. In one aspect geometric symmetry of a PET scanner FOV is used in ordering the data and processing. In one aspect a system matrix LUT comprises total number of system matrix elements equal to a total number of image matrix elements divided by a total number of possible third index values.

US Patent:

8600139, Dec 3, 2013

Filed:

May 4, 2010

Appl. No.:

13/321192

Inventors:

Bin Zhang - Richmond Heights OH, US
Zhiqiang Hu - Twinsburg OH, US
Chi-Hua Tung - Aurora OH, US

Assignee:

Koninklijke Philips N.V. - Eindhoven

International Classification:

G06K 9/00

US Classification:

382131

Abstract:

A method of processing a positron emission tomography (PET) imaging data set () acquired of a subject includes independently localizing each positron-electron annihilation event of the PET imaging data set based on time of flight (TOF) localization of the positron-electron annihilation event to form a generated image (). The generated image may be displayed. The generated image is suitably used as the basis for an initial image of an iterative reconstruction () of the PET imaging data set () to produce a reconstructed image (). A spatial contour () of an image of the subject in the PET imaging data set () is suitably delineated based on the generated image (). A subject attenuation map () for use in PET image reconstruction () is suitably constructed based in part on the spatial contour ().

US Patent:

8611628, Dec 17, 2013

Filed:

May 4, 2009

Appl. No.:

12/990285

Inventors:

Zhiqiang Hu - Twinsburg OH, US
Daniel Gagnon - Twinsburg OH, US
Chi-Hua Tung - Aurora OH, US

Assignee:

Koninklijke Philips N.V. - Eindhoven

International Classification:

G06K 9/00

US Classification:

382131

Abstract:

When compensating for truncated patient scan data acquired by a multi-modal PET/CT or PET/MR imaging system (), such as occurs when a patient is larger than a field of view for an anatomical imaging device, a segmented contour of a non-attenuation-corrected (NAC) PET image is used to identify a contour of the truncated region. An appropriate tissue type is used to fill in truncated regions of a truncated CT or MR image for the attenuation map. The corrected attenuation map is then used to generate an attenuation-corrected PET image of the patient or a region of interest. Alternatively, the system can be employed in PET/CT or PET/MR imaging scenarios where two modalities are performed sequentially (e. g. , not simultaneously), and thus the contour derived from the PET scan can be compared to the CT or MR image to infer potential subject motion between the PET and CT or MR scans. Additionally, the system can be employed in PET imaging scenarios where the contour derived from the NAC PET image is used as emission boundary for scatter correction using single-scatter simulation, in which a tail-fitting procedure utilizes an emission boundary to define pure-scatter tails (e. g.

US Patent:

20070075249, Apr 5, 2007

Filed:

May 17, 2006

Appl. No.:

11/383831

Inventors:

Wenli Wang - Aurora OH, US
Zhiqiang Hu - Highland Heights OH, US

Assignee:

KONINKLIJKE PHILIPS ELECTRONICS NV - Eindhoven

International Classification:

G01T 1/166

US Classification:

250363040

Abstract:

A method and apparatus for performing an iterative image reconstruction uses two or more processors (). The reconstruction task is distributed among the various processors (). In one embodiment, the projection space data () is distributed among the processors (). In another embodiment, the object space () is distributed among the processors ().

US Patent:

20080317194, Dec 25, 2008

Filed:

Oct 17, 2006

Appl. No.:

12/093152

Inventors:

Daniel Gagnon - Twinsburg OH, US
Wenli Wang - Aurora OH, US
Zhiqiang Hu - Twinsburg OH, US

Assignee:

KONINKLIJKE PHILIPS ELECTRONICS N. V. - Eindhoven

International Classification:

A61B 6/00

US Classification:

378 4

Abstract:

A method and apparatus are provided for reconstructing list mode data acquired during a positron emission tomography scan of an object, the data including information indicative of a plurality of detected positron annihilation events. Detected events occurring in a region of interest are identified; the identified events are reconstructed using an iterative reconstruction technique which includes a ray tracing operation to generate volumetric data indicative of the region of interest, wherein the ray tracing operation traces only image matrix elements located in the region of interest; and a human readable image indicative of the volumetric data is generated. In another aspect an image mask and a projection mask are defined correlating to the region of interest; image matrix elements located in the region of interest are determined by applying the image mask; and detected events occurring in a region of interest are identified by applying the projection mask.