A5086656758- Advanced MRI Techniques and Applications
- Medical Imaging Techniques and Applications
- Atomic and Subatomic Physics Research
- MRI in cancer diagnosis
- Radiomics and Machine Learning in Medical Imaging
- Advanced Neuroimaging Techniques and Applications
- Advanced Radiotherapy Techniques
- Advanced X-ray and CT Imaging
- Photoacoustic and Ultrasonic Imaging
- Functional Brain Connectivity Studies
- Radiation Dose and Imaging
- Lung Cancer Diagnosis and Treatment
- Digital Radiography and Breast Imaging
- Alzheimer's disease research and treatments
- Glioma Diagnosis and Treatment
- Medical Imaging and Pathology Studies
Siemens Healthcare (Germany)
2017-2023
New York University
2017-2018
Objectives The aim of this study was to develop a method for tracking respiratory motion throughout full MR or PET/MR studies that requires only minimal additional hardware and no modifications the sequences. Materials Methods Patient is caused by respiration affects quality signal individual radiofrequency receive coil elements. This effect can be detected as modulation monofrequent emitted small portable transmitter placed inside bore (Pilot Tone). frequency selected such it located...
In the last two decades, it has been shown that anatomically-guided PET reconstruction can lead to improved bias-noise characteristics in brain imaging. However, despite promising results simulations and first studies, reconstructions are not yet available for use routine clinical because of several reasons. light this, we investigate whether improvements methods be achieved entirely image domain with a convolutional neural network (CNN). An image-based CNN post-reconstruction approach...
Interest in MR-only treatment planning for radiation therapy is growing rapidly with the emergence of integrated MRI/linear accelerator technology. The purpose this study was to evaluate feasibility using synthetic CT images generated from conventional Dixon-based MRI scans lung cancer. Eleven patients who underwent whole-body PET/MR imaging following a PET/CT exam were randomly selected an ongoing prospective IRB-approved study. Attenuation maps derived Dixon MR Images and atlas-based...
Methods for joint activity reconstruction and attenuation of time-of-flight (TOF) PET data provide an effective solution to correction when no (or incomplete or inaccurate) information on is available. One the main barriers limiting use these methods in clinical practice their lack validation a relatively large patient database. In this contribution, we aim validate performed with maximum-likelihood registration (MLRR) whole-body dataset. Furthermore, partial (because scale problem algorithm...
To describe an approach for detection of respiratory signals using a transmitted radiofrequency (RF) reference signal called Pilot-Tone (PT) and to use the PT creation motion-resolved images based on 3D stack-of-stars imaging under free-breathing conditions.This work explores RF generated by small transmitter, placed outside MR bore. The is received in parallel during each readout. Because amplitude modulated subject's breathing pattern, can be obtained detecting strength over time....
Objectives Respiratory binning of free-breathing magnetic resonance imaging data reduces motion blurring; however, it exacerbates noise and introduces severe artifacts due to undersampling. Deep neural networks can remove but usually require high-quality ground truth images for training. This study aimed develop a network that be trained without this requirement. Materials Methods retrospective was conducted on 33 participants enrolled between November 2016 June 2019. Free-breathing...
Scatter correction is typically done using a simulation of the single scatter, which then scaled to account for multiple scatters and other possible model mismatches. This scaling factor determined by fitting simulated scatter sinogram measured sinogram, only counts along LORs that do not intersect patient body, i.e. 'scatter-tails'. Extending previous work, we propose scale with plane dependent factor, as an additional unknown in maximum likelihood (ML) reconstructions, entire rather than...
Purpose To develop a flexible method for tracking respiratory and cardiac motions throughout MR PET‐MR body examinations that requires no additional hardware minimal sequence modification. Methods The incorporation of contrast‐neutral rosette navigator module following the RF excitation allows robust cardiorespiratory motion with impact on host sequence. Spatial encoding gradients are applied to FID signal desired signals extracted blind source separation technique. This approach is...
Purpose We evaluated the impact of PET respiratory motion correction (MoCo) in a phantom and patients. Moreover, we proposed examined MoCo approach using vector fields (MVFs) from deep‐learning reconstructed short MRI scan. Methods The evaluation was performed study with varying lesion sizes tumor to background ratios (TBRs) static scan as ground truth. MRI‐based MVFs were derived either 2000 spokes (MoCo , 5–6 min acquisition time) Fourier transform reconstruction or 200 P2P200 30–40 s...
Abstract Low-dose x-ray CT is a major research area with high clinical impact. Compressed sensing using view-based sparse sampling and sparsity-promoting regularization has shown promise in simulations, but these methods can be difficult to implement on diagnostic scanners since the beam cannot switched off rapidly enough. An alternative interrupted-beam sampling. SparseCT recently-proposed scheme that achieves by blocking portion of multislit collimator (MSC). The use an MSC necessitates...
Fluorodeoxyglucose (FDG) positron emission tomography-magnetic resonance (PET/MR) is useful for the evaluation of cognitively-impaired patients. This study aims to assess two different attenuation correction (AC) methods (Dixon-MR and atlas-based) versus index-standard computed tomography (CT) AC visual interpretation regional hypometabolism in patients with cognitive impairment. Two board-certified nuclear medicine physicians blindly scored brain region FDG as normal hypometabolic using...
The spatial-temporal relationships between gray and white matter (WM) degeneration during preclinical early symptomatic Alzheimer's disease are poorly understood. We characterized β-amyloid deposition, cortical volume WM in 44 subjects including healthy control (N=23), amnestic mild cognitive impairment (aMCI) (N=19), (N=2). Integrated PET-MRI provided simultaneous measurement of 18F-Florbetapir uptake areas, regional brain volumes from structural MRI, tract integrity metrics diffusion MRI...
In this work, we investigate whether MRI-Based anatomically guided PET reconstruction can be mimicked by a purely image-based convolutional neural network (CNN). The performance of the CNN is evaluated on 49 [ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">18</sup> F]FDG data sets acquired Siemens mMR.
Abstract Background Tau PET offers the potential of in vivo imaging neurofibrillary tangles (NFT) brain to assess Alzheimer’s disease (AD) progression and help guide development disease‐modifying treatments. In this study, we evaluate visualization quantification NFT using simultaneous acquisition MRI [18F]‐MK‐6240 [1]. To overcome limitations spatial resolution resulting partial volume effects (PVE), MRI‐guided reconstruction an asymmetrical Bowsher prior [2,3] was tested. Method...
Zielsetzung The acquisition of an attenuation map for each bed position is essential PET/MR examinations to obtain quantitative PET images. Current correction (AC) methods are based on breath-hold acquisitions thus hampering areas that might be affected by respiratory motion such as the upper abdomen. Here, we investigated a free breathing approach correction.
Ziel/Aim Die Aufnahme einer MRT-Sequenz zur PET-Schwächungskorrektur (AC) ist für die PET/MR essenziell, diese wird in der Regel Atemanhalt aufgenommen. Insbesondere ältere und pädiatrische PatientInnen können von einem Ansatz mit freier Atemtechnik profitieren. In dieser Arbeit wurde Schwächungskorrektur Atmung untersucht.
Since a single diffusion-weighted image can suffer from low SNR, multiple DWI repetitions be averaged to improve which, however, introduce blurring due respiratory motion between different repetitions. Consequently, retrospective gating performed overcome this problem. However, conventional has SNR efficiency as it discards parts of the data and may result in certain slices missing for desired state. This work proposes an efficient Deep Learning-based motion-correction method free-breathing...
Respiratory motion causes signal blurring and image artifacts. Simultaneous PET/MRI allows for MR-assisted correction (MoCo) in PET imaging, leading to improved images detection evaluation of lesions. In this study, we proposed examined a MoCo approach using vector fields (MVFs) from deep-learning reconstructed MRI scan. MRI-based MVFs were derived either 2000 spokes (MoCo , 5-6 minutes acquisition time) Fourier transform reconstruction or 200 P2P200 30-40 seconds Phase2Phase (P2P) then...
Undersampling is desired to reduce scan time but can cause streaking artifacts in stack-of-radial imaging. State-of-the-art deep neural networks such as the U-Net be trained a supervised manner remove produce blurred images and loss of image details. Therefore, we developed 3D generative adversarial network preserve perceptual sharpness while removing artifacts. The used combination loss, L2 structural similarity index loss. We demonstrated feasibility proposed for preserving sharpness.
The acquisition duration of diffusion-weighted imaging (DWI) in the abdomen may cause motion blurring artifacts due to respiratory motion. prevention or removal can be done by breath holding [1] , prospective (automated) triggering during image acquisition, retrospective compensation. Due a typical 4 min multiple holds are required, making this approach unfavorable for routine use. alternative prolongs roughly twofold. Retrospective compensation (MoCo) aims mainly at correction phase errors...
Ziel/Aim MRT-basierte Korrektur von PET-Daten am PET/MRT gewinnt an Aktualität. Abhängig der Atemamplitude ist neben besserer Detektierbarkeit kleiner Läsionen ein positiver Einfluss auf die quantitativen Daten zu erwarten. Diese Pilotstudie vergleicht zwei unterschiedliche Korrekturalgorithmen für eines Biograph mMR (Siemens Healthcare, Erlangen, Germany).