Abstract Chemical exchange saturation transfer (CEST) imaging is a relatively new magnetic resonance contrast approach in which exogenous or endogenous compounds containing either exchangeable protons molecules are selectively saturated and after of this saturation, detected indirectly through the water signal with enhanced sensitivity. The focus review on basic principles underlying CEST similarities to differences conventional magnetization contrast. In imaging, studied mobile instead...

Recent animal studies have shown that D-glucose is a potential biodegradable MRI contrast agent for imaging glucose uptake in tumors. Here, we show the first translation of use to human studies. Chemical exchange saturation transfer (CEST) at single frequency offset optimized detection hydroxyl protons (glucoCEST) was used image dynamic signal changes brain 7T during and after infusion D-glucose. Dynamic glucose-enhanced (DGE) data from four normal volunteers three glioma patients showed...

Purpose Chemical exchange saturation transfer (CEST) imaging is a new MRI technology allowing the detection of low concentration endogenous cellular proteins and metabolites indirectly through their exchangeable protons. A technique, variable delay multi-pulse CEST (VDMP-CEST), proposed to eliminate need for recording full Z-spectra performing asymmetry analysis obtain contrast. Methods The VDMP-CEST scheme involves acquiring images with two (or more) delays between radiofrequency pulses in...

To explore the relationship of amide proton transfer (APT) and nuclear Overhauser enhancement (NOE) signal intensities with respect to different World Health Organization (WHO) brain tumor grades (II IV) at 7T.APT-based NOE-based signals 7T using low-power steady-state chemical exchange saturation (CEST) were compared among de novo primary gliomas WHO IV). The quantitative APT NOE signals, calculated by fitting approach extrapolated semisolid MT reference (EMR) magnetization ratio asymmetry...

Chemical exchange saturation transfer (CEST) is a new approach for generating magnetic resonance imaging (MRI) contrast that allows monitoring of protein properties in vivo. In this method, radiofrequency pulse used to saturate the magnetization specific protons on target molecule, which then transferred water via chemical and detected using MRI. One advantage CEST magnetizations different can be specifically saturated at frequencies. This enables detection multiple targets simultaneously...

Synthetic chemistry has revolutionized the understanding of many biological systems. Small compounds that act as agonists and antagonists proteins, occasionally imaging probes, have contributed tremendously to elucidation pathways. Nevertheless, function thousands proteins is still elusive, designing new probes remains a challenge. Through screening characterization, we identified thymidine analogue probe for expression herpes simplex virus type-1 kinase (HSV1-TK). To detect probe, used...

The current study aims to assign and estimate the total creatine (tCr) signal contribution Z-spectrum in mouse brain at 11.7 T. Creatine (Cr), phosphocreatine (PCr) protein phantoms were used confirm presence of a guanidinium resonance this field strength. Wild-type (WT) knockout mice with guanidinoacetate N-methyltransferase deficiency (GAMT-/-), which have low Cr PCr concentrations brain, tCr Z-spectrum. To concentrations, two pools for around 2 ppm assumed: (i) Lorentzian function...

Genetically engineered reporters have revolutionized the understanding of many biological processes. MRI-based reporter genes can dramatically improve our ability to monitor dynamic gene expression and allow coregistration subcellular genetic information with high-resolution anatomical images. We developed a biocompatible MRI based on human gene, protamine-1 (hPRM1). The arginine-rich hPRM1 (47% arginine residues) generates high contrast chemical exchange saturation transfer (CEST)...

The local presence and concentration of metal ions in biological systems has been extensively studied ex vivo using fluorescent dyes. However, the detection multiple remains a major challenge. We present magnetic resonance imaging (MRI)-based method for noninvasive specific that may be coexisting, tetrafluorinated derivative BAPTA (TF-BAPTA) chelate as 19F analogue existing optical Taking advantage difference ion-specific nuclear (NMR) chemical shift offset (Δω) values between ion-bound free...

Purpose Demonstrate applicability of natural D‐glucose as a T 2 MRI contrast agent. Methods solutions were prepared at multiple concentrations and variable pH. The relaxation rate ( R = 1/ ) was measured 3, 7, 11.7 T. Additional experiments performed on blood Also, mouse infused with (3.0 mmol/kg) dynamic weighted images the abdomen acquired. Results transverse depended strongly glucose concentration solution A maximum change in observed around physiological pH (pH 6.8‐7.8). relaxivities...

Purpose To use the variable delay multipulse (VDMP) chemical exchange saturation transfer (CEST) approach to obtain clean amide proton (APT) and relayed Nuclear Overhauser enhancement (rNOE) CEST images in human brain by suppressing conventional magnetization contrast (MTC) reducing direct water contribution. Methods The VDMP scheme consists of a train RF pulses with specific mixing time. signal respect time shows distinguishable characteristics for protons different rates. Exchange rate...

To propose and evaluate a model for the blood water T1 that takes into account effects of hematocrit fraction, oxygenation erythrocyte hemoglobin concentration, methemoglobin plasma albumin concentration.Whole lysed data were acquired at magnetic fields 3 Tesla (T), 7T, 9.4T, 11.7T using inversion-recovery measurements home-built circulation system maintaining physiological conditions. A quantitative was derived based on multivariable fitting this data.Fitting to allowed determination...

Glycogen plays a central role in glucose homeostasis and is abundant several types of tissue. We report an MRI method for imaging glycogen noninvasively with enhanced detection sensitivity high specificity, using the magnetic coupling between water protons through nuclear Overhauser enhancement (NOE). show vitro that NOE (glycoNOE) signal correlated linearly concentration, while pH temperature have little effect on its intensity. For validation, we imaged glycoNOE changes mouse liver, both...

// Yuguo Li 1,2,* , Hanwei Chen 2,3,4,* Jiadi Xu 1,2 Nirbhay N. Yadav Kannie W. Y. Chan Liangping Luo 4 Michael T. McMahon Bert Vogelstein 5 Peter C.M. van Zijl Shibin Zhou and Guanshu Liu 1 F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA 2 The Russell H. Morgan Department of Radiology Radiological Science, Division MR Research, Johns Hopkins University School Medicine, 3 Radiology, Panyu Central Hospital, Guangzhou, China First...

Purpose Dynamic glucose enhanced (DGE) MRI has shown potential for imaging delivery and blood–brain barrier permeability at fields of 7T higher. Here, we evaluated issues involved with translating d ‐glucose weighted chemical exchange saturation transfer (glucoCEST) experiments to the clinical field strength 3T. Methods Exchange rates different hydroxyl proton pools field‐dependent T 2 relaxivity water in solution were used simulate spectra (Z‐spectra) DGE signal differences as a function...

Abstract Frequency‐labeled exchange transfer is a promising MRI technique for labeling and detecting exchanging protons of low‐concentration solutes through the water signal. Early frequency‐labeled studies have used off‐resonance excitation‐based schemes that are well suited to study rapidly or molecules far from resonance (e.g., in paramagnetic contrast agents) slowly close some amide protons). However, not efficient water. Here, we show new scheme with excitation pulses applied on gives...

Abstract The optimal exchange properties for chemical saturation transfer (CEST) contrast agents on 3 T clinical scanners were characterized using continuous wave transfer, and it was demonstrated that the exchangeable protons in phenols can be tuned to reach these criteria through proper ring substitution. Systematic modification allows shift of positioned between 4.8 12 ppm from water enables adjustment proton rate maximize CEST at shifts. In particular, 44 hydrogen‐bonded are investigated...

Purpose 3‐O‐Methyl‐D‐glucose (3‐OMG) is a nonmetabolizable structural analog of glucose that offers potential to be used as CEST‐contrast agent for tumor detection. Here, we explore it CEST‐detection malignant brain tumors and compare with D‐glucose. Methods Glioma xenografts U87‐MG cell line were implanted in five mice. Dynamic 3‐OMG weighted images collected using CEST‐MRI at 11.7 T single offset 1.2 ppm, showing the effect accumulation contrast tumor, following an intravenous injection (3...

Purpose To investigate the use of natural dextrans as nano‐sized chemical exchange saturation transfer (CEST) MRI probes for characterizing size‐dependent tumor vascular permeability. Methods Dextrans different molecular weight (10, 70, 150, and 2000 kD) were characterized their CEST contrast. Mice ( N = 5) bearing CT26 subcutaneous colon tumors injected intravenously with 10 kD (D10, 6 nm) 70 (D70, 12 dextran at a dose 375 mg/kg. The CEST‐MRI signal in was assessed before approximately 40...

Purpose To develop an on-resonance variable delay multipulse (VDMP) scheme to image magnetization transfer contrast (MTC) and the chemical exchange saturation (CEST) of total fast-exchanging protons (TFP) with rate above approximately 1 kHz. Methods A train high power binomial pulses was applied at water resonance. The interpulse delay, called mixing time, varied observe its effect on signal reduction, allowing separation quantification MTC CEST contributions as a result their different...

Purpose To develop a method that can separate and quantify the fast (>1 kHz) slow exchange transfer magnetization components in Z‐spectra. Methods Z‐spectra were recorded as function of mixing time using train selective pulses providing variable‐delay multipulse build‐up curves. Fast separated quantified on voxel‐by‐voxel basis by fitting time–dependent CEST signal 3‐pool model. Results Phantom studies glutamate solution, bovine serum albumin hair conditioner showed capability proposed to...