The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In this work we proposed a new respiratory and cardiac motion correction method for cardiac PET/MR imaging by using 2D-MRI image navigator technique and novel dynamic MRI reconstruction method. In the PET/MR acquisition, ECG trigger is used. After trigger starts, 2D-MRI image navigator and golden angle cardiac imaging sequence are applied. After acquisition, cardiac MRI data and PET data are binned...
We propose a spatially adaptive Non-Local Means (NLM) post-filtering approach for whole-body clinical Positron Emission Tomography (PET) imaging. Our approach is aimed at avoiding different effective smoothing strengths in different organs that result from with traditional non-adaptive NLM. We vary the smoothing strength according to the intensity level around a given voxel such that regions with...
A study is described that investigates the capacity for mathematical observer models to mimic the performance of human observers in a PET lesion detection task. FDG-PET data from seventeen tuberculosis patients presenting diffuse hyper-metabolic lung lesions were selected for the study, to include a wide range of lesion sizes and contrasts. All subjects were scanned on a simultaneous PET/MR system...
Positron emission tomography (PET) images suffer from partial volume (PV) effects due to the poor spatial resolution of the PET system. In cardiac imaging, additional blurring is caused by the breathing motion and the beating of the heart. Dual gating of the cardiac datasets is one possible approach to remove the motion blur [1], but it dramatically reduces the statistics of the dataset and leads...
State of the art PET-MR systems are capable of performing both PET and MR measurements simultaneously. However, the resulting data sets are usually processed in two separate reconstruction pipelines. The goal of this work is to complement simultaneous data acquisition with a new multi-modality reconstruction framework based on second order total generalized variation that simultaneously reconstructs...
The point-spread-functions (PSFs) of reconstructed images can be deformed due to the detector properties, such as the resolution and depth-of-interaction effects, and data geometries, such as the limited angular coverage in dual-panel PET systems. The PSF deformations cause decreased quantitative accuracy and consistency of the uptake measurements across the field of view. While reconstruction models...
Current recommendation for using PET imaging in the assessment of solitary pulmonary nodules is limited to sizes greater than 8mm. Our objective was to assess the scan time required in order to improve discrimination of small lesions with realistic FDG uptake using XCAT phantom based simulations. Dynamic time-activity curves were generated to simulate uptake in different organs and a subset of these...
Low count PET studies usually suffer from high image noise and quantitative bias in reconstructed image. This is particularly significant for short frames (temporal-ROI, or TROI) in dynamic PET studies, which in some cases may be as short as 30 seconds or less. In this paper, we proposed a method to improve the quality of the reconstructed short frame by utilizing information from a longer acquisition...
Scanners with different performance characteristics and reconstruction protocols can produce images that show large variations in uptake in small lesions. There have been a number of studies aimed at reducing this variability for clinical trials using phantom data to optimize the acquisition and/or reconstruction protocols. The underlying assumption is that the protocols that harmonize the phantom...
In a low contrast lesion detection experiment, large amounts of repeated measurements on the same object are typically required in order to achieve a good estimation of statistics. One way to obtain these many realizations can be through repeatedly scanning the low contrast object, which however, is a challenge with Positron Emission Tomography (PET) imaging due to the decaying nature of radionuclides...
Positron emission tomography (PET) is a valuable clinical tool for cancer staging and monitoring response to treatment, but it is limited by its relatively poor resolution and high noise level. In this study, we investigated the impact of using anatomical information, either during or post reconstruction, for PET imaging of sub-cm lung nodules. The XCAT phantom with four inserted lung lesions (diameter:...
PET lesion detectability performance characterization with clinically relevant background conditions is difficult to perform with existing phantoms and inserts. The backgrounds of conventional phantoms are often uniform water regions with lesions represented as tillable chambers with casings that create a region of zero activity surrounding the high-activity feature. 3D-printing has enabled the creation...
We present an image-domain point spread function (PSF) modeling approach for resolution recovery where spatially varying PSF kernel widths are adjusted based on data quality. This approach attempts to maximize contrast recovery while minimizing edge artifacts (ringing) associated with PSF modeling. We choose broader PSF kernels for noisier datasets where the extent of ringing is comparable to noise...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.