A5035862378- Advanced MRI Techniques and Applications
- Advanced NMR Techniques and Applications
- Atomic and Subatomic Physics Research
- Medical Imaging Techniques and Applications
- Electron Spin Resonance Studies
- Radiomics and Machine Learning in Medical Imaging
- Enzyme Structure and Function
- NMR spectroscopy and applications
- Solid-state spectroscopy and crystallography
- Advanced X-ray and CT Imaging
- Advanced Neuroimaging Techniques and Applications
- Cancer, Hypoxia, and Metabolism
- Lanthanide and Transition Metal Complexes
- Fibroblast Growth Factor Research
- Sparse and Compressive Sensing Techniques
- Phagocytosis and Immune Regulation
- Nuclear Physics and Applications
- MRI in cancer diagnosis
- Amino Acid Enzymes and Metabolism
- Photoacoustic and Ultrasonic Imaging
- Prostate Cancer Diagnosis and Treatment
- Ultrasound and Hyperthermia Applications
- Advanced Radiotherapy Techniques
- Prostate Cancer Treatment and Research
- Medical Image Segmentation Techniques
University of California, San Francisco
2016-2025
University of California, Berkeley
2016-2025
University of California System
2016-2025
Neurological Surgery
2010-2025
Merck & Co., Inc., Rahway, NJ, USA (United States)
2024
Universidad Católica de Santa Fe
2020-2022
City College of San Francisco
2018-2020
Graduate Theological Union
2010-2017
San Francisco VA Medical Center
2017
HeartVista (United States)
2016
Metabolic imaging with hyperpolarized pyruvate was used to safely and noninvasively visualize prostate tumors in patients.
Purpose A calibrationless parallel imaging reconstruction method, termed simultaneous autocalibrating and k-space estimation (SAKE), is presented. It a data-driven, coil-by-coil method that does not require separate calibration step for estimating coil sensitivity information. Methods In SAKE, an undersampled, multichannel dataset structured into single data matrix. The then formulated as low-rank matrix completion problem. An iterative solution implements projection-onto-sets algorithm with...
Accurate quantification of uptake on PET images depends accurate attenuation correction in reconstruction. Current MR-based methods for body use a fat and water map derived from 2-echo Dixon MRI sequence which bone is neglected. Ultrashort-echo-time or zero-echo-time (ZTE) pulse sequences can capture information. We propose the patient-specific multiparametric consisting proton-density-weighted ZTE to directly synthesize pseudo-CT with deep learning model: we call this method (ZeDD CT)....
The aim of this study was to determine the specific nature and course olfactory deficits in Alzheimer's disease. Previous studies had noted impaired odor identification, but there no unanimity about presence detection deficits.Odor identification tested 55 patients with disease 57 elderly control subjects by using University Pennsylvania Smell Identification Test. Odor assessed 46 40 a forced-choice threshold test geraniol as odorant.Significant were present who earliest stages cognitive...
Abstract Hyperpolarized 13 C MR spectroscopic imaging can detect not only the uptake of pre‐polarized molecule but also its metabolic products in vivo, thus providing a powerful new method to study cellular metabolism. Imaging dynamic perfusion and conversion these metabolites provides additional tissue information requires methods for efficient hyperpolarization usage rapid acquisitions. In this work, we have developed time‐resolved 3D acquiring hyperpolarized data by combining compressed...
In order to compare in vivo metabolism between malignant gliomas and normal brain, 13C magnetic resonance (MR) spectroscopic imaging data were acquired from rats with human glioblastoma xenografts (U-251 MG U-87 MG) rats, following injection of hyperpolarized [1-13C]-pyruvate. The median signal-to-noise ratio (SNR) lactate, pyruvate, total observed carbon-13 resonances, as well their relative ratios, calculated voxels containing Gadolinium-enhanced tissue T1 postcontrast images for tumors...
Reduction and oxidation (redox) chemistry is involved in both normal abnormal cellular function, processes as diverse circadian rhythms neurotransmission. Intracellular redox maintained by coupled reactions involving NADPH, glutathione (GSH), vitamin C, well their corresponding oxidized counterparts. In addition to functioning enzyme cofactors, these reducing agents have a critical role dealing with reactive oxygen species (ROS), the toxic products of oxidative metabolism seen culprits...
To investigate the utility of a free-breathing ultrashort echo time (UTE) sequence for evaluation small pulmonary nodules in oncology patients by using hybrid positron emission tomography (PET)/magnetic resonance (MR) imaging system and to compare nodule detection rate between UTE conventional three-dimensional gradient-recalled-echo (GRE) technique.In this HIPAA-compliant, institutional review board-approved prospective study, 82 were identified eight with extrathoracic malignancies....
Purpose Hyperpolarized carbon‐13 ( 13 C) metabolic imaging is a noninvasive modality for evaluating real‐time metabolism. The purpose of this study was to develop and implement experimental strategies using [1‐ C]pyruvate probe in vivo metabolism patients with brain tumors other neurological diseases. Methods C radiofrequency coils pulse sequences were tested phantom performed 3 Tesla whole‐body scanner. Samples polarized SPINlab system. Dynamic data acquired from 8 previously diagnosed...
Abstract High polarization of nuclear spins in liquid state through hyperpolarized technology utilizing dynamic has enabled the direct monitoring 13 C metabolites vivo at a high signal‐to‐noise ratio. Acquisition time limitations due to T 1 decay signal require accelerated imaging methods, such as compressed sensing, for optimal speed and spatial coverage. In this paper, design testing new echo‐planar three‐dimensional magnetic resonance spectroscopic (MRSI) sensing sequence is presented....
Purpose To describe a method for converting Zero TE (ZTE) MR images into X‐ray attenuation information in the form of pseudo‐CT and demonstrate its performance (1) correction (AC) PET/MR (2) dose planning MR‐guided radiation therapy (RTP). Methods Proton density‐weighted ZTE were acquired as input MR‐based conversion, providing efficient capture short‐lived bone signals, flat soft‐tissue contrast, (3) fast robust 3D imaging. After bias normalization, segmented bone, soft‐tissue, air by means...
Abstract Background Hyperpolarized (HP) 13 C-pyruvate MRI is a stable-isotope molecular imaging modality that provides real-time assessment of the rate metabolism through glycolytic pathways in human prostate cancer. Heretofore this has been successfully utilized cancer only localized disease. This pilot clinical study investigated feasibility and performance HP MR metabolic patients with metastases to bone and/or viscera. Methods Six who had metastatic castration-resistant were recruited....
MRI using hyperpolarized (HP) carbon‐13 pyruvate is being investigated in clinical trials to provide non‐invasive measurements of metabolism for cancer and cardiac imaging. In this project, we applied HP [1‐ 13 C]pyruvate dynamic prostate measure the conversion from lactate, which expected increase aggressive cancers. The goal work was develop test analysis methods improved quantification metabolic conversion. work, compared specialized kinetic modeling estimate pyruvate‐to‐lactate rate, k P...
Abstract MRI with hyperpolarized (HP) 13 C agents, also known as HP MRI, can measure processes such localized metabolism that is altered in numerous cancers, liver, heart, kidney diseases, and more. It has been translated into human studies during the past 10 years, recent rapid growth largely based on increasing availability of agent preparation methods suitable for use humans. This paper aims to capture current successful practices [1‐ C]pyruvate—by far most commonly used agent, which sits...
Hyperpolarized 13C labeled molecular probes have been used to investigate metabolic pathways of interest as well facilitate in vivo spectroscopic imaging by taking advantage the dramatic signal enhancement provided DNP. Due limited lifetime hyperpolarized nucleus, with decay dependent on T1 relaxation, carboxylate carbons primary targets for development probes. The use these carbon nuclei makes it difficult upstream glycolytic processes, which related both cancer metabolism other...
Abstract Purpose: To demonstrate dynamic imaging of a diffusible perfusion tracer, hyperpolarized [ 13 C]urea, for regional measurement blood flow in preclinical cancer models. Materials and Methods: A pulse sequence using balanced steady state free precession (bSSFP) was developed, with progressively increasing flip angles efficient sampling the magnetization. This allowed temporal volumetric C]urea signal. Regional signal dynamics were quantified kidneys liver, estimates relative flows...
Hyperpolarized [1-(13)C]-pyruvate is an exciting new agent for the in vivo study of cellular metabolism and a potential cancer biomarker. The nature hyperpolarized signal poses unique challenges because its short duration loss magnetization with every excitation. In this study, we applied novel efficient time-resolved MR spectroscopic imaging (MRSI) method to investigate prostate model localized temporal dynamics uptake conversion metabolic products, specifically [1-(13)C]-lactate. This...
<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">13</sup> C steady state free precession (SSFP) magnetic resonance imaging and effective spin-spin relaxation time (T2) mapping were performed using hyperpolarized [ C] urea C, xmlns:xlink="http://www.w3.org/1999/xlink">15</sup> N <sub xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ] injected intravenously in rats. labeling gave large T2 increases both solution vivo due to the elimination of a...
Abstract Mutations of the isocitrate dehydrogenase 1 (IDH1) gene are among most prevalent in low-grade glioma and secondary glioblastoma, represent an early pathogenic event, associated with epigenetically driven modulations metabolism. Of particular interest is recently uncovered relationship between IDH1 mutation decreased activity branched-chain amino acid transaminase (BCAT1) enzyme. Noninvasive imaging methods that can assess BCAT1 could therefore improve detection mutant tumors aid...