Now showing items 1-10 of 250
Statistical Emission Image Reconstruction for Randoms-Precorrected PET Scans Using Negative Sinogram Values
(IEEE, 2003-10-19)
Many conventional PET emission scans are corrected for accidental coincidence (AC) events, or randoms, by real-time subtraction of delayed-window coincidences, leaving only the randoms-precorrected data available for image ...
Effect of Including Detector Response in SPECT Quantification of Focal I-131 Therapy
(IEEE, 2001-11-04)
With a regularized strip-integral (1D) SAGE reconstruction, circular-orbit SPECT estimates of phantom focal 131-I activity vary with changes in the level of uniform background. They also vary with changes in image resolution ...
Intensity-Based Image Registration Using Robust Correlation Coefficients
(IEEE, 2004-11-01)
The ordinary sample correlation coefficient is a
popular similarity measure for aligning images from the same
or similar modalities. However, this measure can be sensitive to
the presence of “outlier” objects that appear ...
Incorporation of System Resolution Compensation (RC) in the Ordered-Subset Transmission (OSTR) Algorithm for Transmission Imaging in SPECT
(IEEE, 2006-06-26)
In order to reconstruct attenuation maps with improved spatial resolution and quantitative accuracy, we developed an approximate method of incorporating system resolution compensation (RC) in the ordered-subset transmission ...
Endoscopic Ultrasound Spectrum Analysis for In Vivo Characterization of Pancreatic and Lymph Node Tissue: A Pilot Study
(Elsevier, 2007-12)
Background: EUS is limited by variability in the examiner’s subjective interpretation of
B-scan images to differentiate between normal, inflammatory, and malignant tissue. By using information otherwise discarded by ...
Fast kVp-Switching Dual Energy CT for PET Attenuation Correction
(IEEE, 2009-10-24)
X-ray CT images are used routinely for attenuation correction in PET/CT systems. However, conventional CT-based attenuation correction (CTAC) can be inaccurate in regions containing iodine contrast agent. Dual-energy (DE) ...
Quantitative I-131 SPECT Reconstruction using CT Side Information from Hybrid Imaging
(IEEE, 2009-10-24)
A penalized-likelihood (PL) SPECT reconstruction method using a modified regularizer that accounts for anatomical boundary side information was implemented to achieve accurate estimates of both the total target activity ...
Spatially -Variant Roughness Penalty Design for Uniform Resolution in Penalized-Likelihood Image Reconstruction
(IEEE, 1998-10-04)
Traditional space-invariant regularization schemes in tomographic image reconstruction using penalized likelihood estimators produce images with nonuniform resolution properties. The local point spread functions that ...
3D PET Reconstruction with FORE and WLS-OS-EM
(IEEE, 2002-11-10)
2D PET reconstructions by the ordered subsets version of the ML-EM algorithm (typically referred to as "OS-EM") assume that the random- and scattered-corrected coincidence data retain their Poisson statistics. Negative ...
Improved Penalized Likelihood Reconstruction of Anatomically Correlated Mmission Data
(IEEE, 1996-09-16)
This paper presents a method for incorporating anatomical NMR boundary side information into penalized maximum likelihood (PML) emission image reconstructions. The NMR boundary is parameterized as a periodic spline curve ...