A5039591873- Advanced MRI Techniques and Applications
- Atomic and Subatomic Physics Research
- Neonatal and fetal brain pathology
- Advanced NMR Techniques and Applications
- Ultrasound and Hyperthermia Applications
- Advanced Neuroimaging Techniques and Applications
- Hearing Loss and Rehabilitation
- MRI in cancer diagnosis
- Optical Imaging and Spectroscopy Techniques
- Biochemical effects in animals
- Cardiac Arrest and Resuscitation
- Traumatic Brain Injury and Neurovascular Disturbances
- Quantum, superfluid, helium dynamics
- Photoacoustic and Ultrasonic Imaging
- Bone and Joint Diseases
- NMR spectroscopy and applications
- Lanthanide and Transition Metal Complexes
- Medical Imaging Techniques and Applications
- Advanced X-ray and CT Imaging
- Thermal Regulation in Medicine
- Anesthesia and Neurotoxicity Research
- Neural dynamics and brain function
- Metabolism and Genetic Disorders
- Non-Invasive Vital Sign Monitoring
- Cardiac Imaging and Diagnostics
Philips (Netherlands)
2012-2025
Philips (United Kingdom)
2007-2021
Philips (Finland)
2008-2013
University of Exeter
2003-2009
University College London
1994-2003
University College Hospital
2002
UCL Australia
1997
Middlesex Hospital
1994
Royal London Hospital
1994
Hammersmith Hospital
1994
The authors have used an intensity modulated optical spectrometer, which measures the phase shift across tissue experienced by near-infrared light, to determine absolute pathlength through tissue. instrument is portable and takes only 5 s record at four wavelengths (690 nm, 744 807 nm 832 nm). divided known spacing between light source detector on skin differential factor (DPF) previous studies shown approximately constant for spacings greater than 2.5 cm. DPF results are presented...
The purpose of this article is to define the relations symphysis pubis and capsular tissues adductor rectus abdominis soft-tissue attachments on cadaver dissection correlate with MRI anterior pelvis.Seventeen cadavers (8 males 9 females; mean age, 80 years) were dissected bilaterally. Rectus muscles traced further pubic defined. Ten asymptomatic (mean 17; age range, 16.5-29 male athletes underwent 1.5-T pelvis two surface microcoils (each 42 mm in diameter). An axial T2-weighted turbo...
Objective To determine whether the internal auditory canal (IAC) can be visualized using magnetic resonance imaging (MRI) in users of a cochlear implant (CI) model that safely undergo MRI at 3 T. Patients Four normally hearing controls and three individuals unilaterally implanted with HiRes Ultra 3D (Advanced Bionics LLC, California, USA). Interventions Participants underwent T sequences appropriate for postoperative surveillance IAC. Images were acquired after placing fully functional,...
Using a 100-element tactile stimulator on the fingertip during functional-magnetic-resonance imaging, brain areas were identified that selectively activated by moving vibrotactile stimulus (the sensation of line being dragged over fingertip). Activation patterns elicited motion, contrasted to an equivalent stationary stimulus, compared in six human subjects with those generated visual stimulus. Results provide further evidence for neuroanatomical convergence tactile-motion processing and...
To re-engineer a standard clinical magnetic resonance (MR) imaging system to enable the acquisition, in same breath hold, of lung images from two hyperpolarized gases (helium 3 [(3)He] and xenon 129 [(129)Xe]) with simultaneous registered anatomic proton (hydrogen 1 [(1)H]) MR structure.Studies (3)He (129)Xe were performed National Research Ethics Committee approval, informed consent volunteer. (1)H-(3)He-(129)Xe was achieved by using mutually decoupled nested radiofrequency coil hardware...
This study sought to clinically validate a novel 3-dimensional (3D) ultrafast cardiac magnetic resonance (CMR) protocol including cine (anatomy and function) late gadolinium enhancement (LGE), each in single breath-hold.CMR is the reference tool for imaging but time-consuming.A comprising isotropic 3D (Enhanced sensitivity encoding [SENSE] by Static Outer volume Subtraction [ESSOS]) LGE sequences was compared with standard cine+LGE prospective of 107 patients (age 58 ± 11 years; 24% female)....
Changes in physiological parameters such as cerebral blood flow, volume, oxygen extraction, and the size distribution of vessels, result changes local concentration deoxyhaemoglobin ([dHb]). The purpose this study was to quantitatively investigate dependence R2* relaxation rate upon [dHb] per voxel. Five neonatal piglets were studied a 7 T/20 cm bore magnet. MRI conducted using 2.5 diameter surface coil placed over parietal lobes. Four progressively T2*-weighted images acquired, allowing...
Abstract Cerebral apparent diffusion coefficients {ADCs) were determined in nine newborn piglets before and for 48 h after transient hypoxia‐ischemia. Phosphorus MRS revealed severely reduced cerebral energy metabolism during the insult an apparently complete recovery 2 resuscitation commenced. At this time, mean ADC over imaging slice (ADC global ) was 0.88 (0.04) × 10 9 m · s 1 (mean (SD}), which close to baseline value of 0.92 (0.4) . In seven animals, a “secondary” failure then...
The aim of this study was to optimise a pulse sequence for high‐resolution imaging sensitive the effects conventional macromolecular magnetisation transfer (MT m ) and nuclear Overhauser enhancement (NOE), use it investigate variations in these parameters across cerebral cortex. A high‐spatial‐resolution transfer‐prepared turbo field echo (MT‐TFE) designed have high sensitivity MT NOE effects, whilst being robust B 0 1 inhomogeneities, producing good point spread function This achieved by...
Sodium magnetic resonance imaging ((23)Na-MRI) of the brain has shown changes in (23)Na signal as a hallmark various neurological diseases such stroke, Alzheimer's disease, Multiple Sclerosis and Huntington's disease. To improve scan times image quality, we have implemented 3D-Cones (CN) sequence for vivo MRI.Using signal-to-noise (SNR) measurement performance, CN is compared against more established 3D-radial k-space sampling schemes featuring cylindrical stack-of-stars (SOS) 3D-spokes...
Coupling of right ventricular (RV) contractility to afterload is maintained at rest in the early stages pulmonary arterial hypertension (PAH), but exercise may unmask depleted contractile reserves. We assessed whether elevated reduces RV reserve despite compensated resting function using noninvasive imaging. Fourteen patients with PAH (mean age: 39.1 yr, 10 women and 4 men) 34 healthy control subjects ageL 35.6 17 completed real-time cardiac magnetic resonance imaging during submaximal...
Purpose To assess the feasibility of using dissolved hyperpolarized xenon‐129 ( 129 Xe) MRI to study renal physiology in humans at 3 T. Methods Using a flexible transceiver RF coil, dynamic and spatially resolved Xe spectroscopy was performed abdomen after inhalation gas with healthy male volunteers. A transmit‐only receive‐only coil array purpose‐built focus excitation enhance sensitivity for imaging uptake kidneys spoiled gradient echo balanced steady‐state sequences. Results spectroscopy,...
Oxidative stress (OS) plays a central role in the progression of liver disease and damage to by toxic xenobiotics. We have developed methods for noninvasive assessment hepatic OS defenses measuring flux through glutathione (GSH) synthesis pathway. 13 C-labeled GSH is endogenously produced detected vivo magnetic resonance after administration [2- C]-glycine. report on successful first-ever human demonstration this approach as well preclinical studies demonstrating perturbed metabolism models...
Abstract Purpose To compare susceptibility effects in hyperpolarized 3 He lung MRI at the clinically relevant field strengths of 1.5T and 3T. Materials Methods Susceptibility‐related B 0 inhomogeneity was evaluated on a macroscopic scale by mapping via phase difference. Subpixel were quantified T . Comparison made between ventilation images obtained from same volunteers both strengths. Results The maps 3T show enhanced off‐resonance close to diaphragm ribs due differences. average voxel (20...
Abstract Hypercapnia and hyperoxia give rise to vasodilation vasoconstriction, respectively. This study investigates the influence of hypercapnia on venous vessel size in human brain. Venous radii were measured response hyperoxia. The determined by calculation changes R 2 * that are induced breathing 6% CO or pure oxygen. experimental paradigm consisted two 3‐min intervals inhaling 100% O interleaved with three 2‐min air. Hypercapnic hyperoxic experiments performed eight subjects a 3T...
In imaging of human lungs with hyperpolarised noble gases, measurements apparent diffusion coefficient (ADC) and relaxation time provide valuable information for the assessment lung microstructure. this work, a sequence was developed interleaved acquisition ventilation images, ADC, T 2 * flip angle maps in single scan from dose inhaled 3 He at T. Spatially registered images parametric were obtained. The total reduced by random undersampling k‐space reconstruction using compressed sensing...