Search Results - "Manjeshwar, Ravindra M."

Quantitative comparison of OSEM and penalized likelihood image reconstruction using relative difference penalties for clinical PET by Ahn, Sangtae, Ross, Steven G, Asma, Evren, Miao, Jun, Jin, Xiao, Cheng, Lishui, Wollenweber, Scott D, Manjeshwar, Ravindra M

“…Ordered subset expectation maximization (OSEM) is the most widely used algorithm for clinical PET image reconstruction. OSEM is usually stopped early and…”
Get more information

Evaluation of lesion detectability in positron emission tomography when using a convergent penalized likelihood image reconstruction method by Wangerin, Kristen A, Ahn, Sangtae, Wollenweber, Scott, Ross, Steven G, Kinahan, Paul E, Manjeshwar, Ravindra M

“…We have previously developed a convergent penalized likelihood (PL) image reconstruction algorithm using the relative difference prior (RDP) and showed that it…”
Get full text

Evaluation of the Accuracy and Robustness of a Motion Correction Algorithm for PET Using a Novel Phantom Approach by Wollenweber, S. D., Gopalakrishnan, G., Thielemans, K., Manjeshwar, R. M.

“…We introduce the use of a novel physical phantom to quantify the performance of a motion-correction algorithm. The goal of the study was to assess a PET-PET…”
Get full text

Comparison of different methods for data-driven respiratory gating of PET data by Thielemans, Kris, Schleyer, Paul, Marsden, Paul K., Manjeshwar, Ravindra M., Wollenweber, Scott D., Ganin, Alexander

“…Respiratory movement degrades image quality in PET/CT. The first step in correcting for movement is to gate the data into different motion states. In current…”
Get full text

Analysis of the effects of errors in attenuation maps on PET quantitation in TOF PET by Ahn, Sangtae, Lishui Cheng, Manjeshwar, Ravindra M.

“…Attenuation correction is critical to positron emission tomography (PET) quantitation. Errors in an attenuation map propagate into PET image reconstruction,…”
Get full text

Using PCA to detect head motion from PET list mode data by Thielemans, Kris, Schleyer, Paul, Dunn, Joel, Marsden, Paul K., Manjeshwar, Ravindra M.

“…PET can be used for studying the brain. However, structures in the brain are small and results can be affected by patient motion, especially during dynamic PET…”
Get full text

Quantitation of small-animal (124)I activity distributions using a clinical PET/CT scanner by González Trotter, Dinko E, Manjeshwar, Ravindra M, Doss, Mohan, Shaller, Calvin, Robinson, Matthew K, Tandon, Reeti, Adams, Gregory P, Adler, Lee P

“…Time-dependent PET imaging can be an important tool in the assessment of radiotracer performance in murine models. We have performed a quantitative analysis of…”
Get full text

Comparison of numerical convergence speeds of convergent and accelerated algorithms for penalized likelihood PET image by Lishui Cheng, Asma, Evren, Ahn, Sangtae, Manjeshwar, Ravindra M.

“…Computational cost is a major challenge for 3D PET image reconstruction. Traditional ordered subsets based methods, such as OS-EM, accelerate the…”
Get full text

Power laws for image quality measures in PET penalized-likelihood image reconstruction by Sangtae Ahn, Asma, Evren, Ross, Steven G., Manjeshwar, Ravindra M.

“…Most image reconstruction methods have parameters for users to determine: for example, an iteration number and post-reconstruction filter parameters in OSEM,…”
Get full text

Partial volume correction for penalized-likelihood image reconstruction in oncological PET applications by Sangtae Ahn, Asma, Evren, Ross, Steven G., Manjeshwar, Ravindra M.

“…Partial volume errors, caused by finite image resolution, that is, blurring in reconstructed images, prevent accurate quantitation of lesion uptake in…”
Get full text

Image reconstruction in rectangular PET systems using distance-driven projections by Hua Qian, Wangerin, Kristen A., Wagadarikar, Ashwin, Manjeshwar, Ravindra M., MacDonald, Lawrence R., Kinahan, Paul E.

“…An image reconstruction algorithm for rectangular PET scanner was developed using distance-driven projections. The geometrical sensitivity of the tubes of…”
Get full text

Objective PET lesion segmentation using a spherical mean shift algorithm by Sebastian, Thomas B, Manjeshwar, Ravindra M, Akhurst, Timothy J, Miller, James V

“…PET imagery is a valuable oncology tool for characterizing lesions and assessing lesion response to therapy. These assessments require accurate delineation of…”
Get more information

Image-based correction for mismatched attenuation in PET images by Thielemans, Kris, Asma, Evren, Manjeshwar, Ravindra M., Ganin, Alex, Spinks, Terence J.

“…Attenuation correction is essential for quantification in PET. The attenuation estimate is normally based on an additional measurement, e.g. transmission scan…”
Get full text

Data-driven dual-gating for cardiac PET by Thielemans, Kris, Schleyer, Paul, Marsden, Paul K., Teuho, Jarmo, Teras, Mika, Bettinardi, Valentino, Menezes, Leon, Manjeshwar, Ravindra M., Stearns, Charles W.

“…Image quality in cardiac PET is impaired by both respiratory and cardiac motion. Dual-gating has been proposed as a means to obtain sinograms in various motion…”
Get full text

Accurate and consistent lesion quantitation with clinically acceptable penalized likelihood images by Asma, Evren, Ahn, Sangtae, Ross, Steven G., Chen, Anthony, Manjeshwar, Ravindra M.

“…Clinical widespread use of edge-preserving penalized-likelihood (PL) methods has been hindered by the properties of the resulting images such as blocky…”
Get full text

Convergent iterative algorithms for joint reconstruction of activity and attenuation from time-of-flight PET data by Sangtae Ahn, Hua Qian, Manjeshwar, Ravindra M.

“…Joint reconstruction of activity and attenuation maps from emission data only, while being a long-standing problem in emission tomography, has been gaining…”
Get full text

Hyper-efficient visual detection of targets in noise by Manjeshwar, R.M., Wilson, D.L.

“…We compared human detection of visual targets in noisy images with the theoretical optimum from a matched filter. Using a small, thin target with vertically…”
Get full text

Adaptive acquisition protocol design for local CNR maximization in flexible SPECT and PET scanners by Asma, E, Manjeshwar, R M

“…We present an adaptive acquisition protocol design technique with the goal of improving local contrast-to-noise ratios (CNR) for flexible SPECT and PET…”
Get full text

Incorporating count-rate dependence into model-based PET scatter estimation by Stearns, C. W., Manjeshwar, R. M.

“…Pile-up in a PET detector changes the sensitivity of the detector to unscattered and scattered annihilation photons differently. If the detection of a 511 keV…”
Get full text

Object size dependency of noise strength and correlation patterns for TOF and non-TOF PET by Asma, E., Ahn, S., Manjeshwar, R. M.

“…We investigate noise strength and correlation length tradeoffs for non time-of-flight (TOF) and TOF penalized likelihood image reconstruction as functions of…”
Get full text