Andrew G Webb

Summary

Affiliation: Leiden University Medical Center
Country: The Netherlands

Publications

  1. doi request reprint Improved signal to noise in proton spectroscopy of the human calf muscle at 7 T using localized B1 calibration
    Maarten J Versluis
    Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
    Magn Reson Med 63:207-11. 2010
  2. pmc MRI and localized proton spectroscopy in human leg muscle at 7 Tesla using longitudinal traveling waves
    Andrew G Webb
    C J Gorter Center for High Field Magnetic Resonance Imaging, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
    Magn Reson Med 63:297-302. 2010
  3. doi request reprint Evaluation of plasma-based transmit coils for magnetic resonance
    A G Webb
    C J Gorter Center for High Field MRI, Leiden University Medical Center, The Netherlands Electronic address
    J Magn Reson 261:49-53. 2015
  4. doi request reprint Cavity- and waveguide-resonators in electron paramagnetic resonance, nuclear magnetic resonance, and magnetic resonance imaging
    Andrew Webb
    C J Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands Electronic address
    Prog Nucl Magn Reson Spectrosc 83:1-20. 2014
  5. pmc Detectability of absorption and reduced scattering coefficients in frequency-domain measurements using a realistic head phantom
    Xiaofeng Zhang
    Department of Radiology, Duke University Medical Center, DUMC 3808, Durham, NC 27710, USA
    Sensors (Basel) 13:152-64. 2013
  6. doi request reprint Radiofrequency microcoils for magnetic resonance imaging and spectroscopy
    A G Webb
    C J Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
    J Magn Reson 229:55-66. 2013
  7. doi request reprint Visualization and characterization of pure and coupled modes in water-based dielectric resonators on a human 7T scanner
    A G Webb
    Department of Radiology, C3 Q, Leiden University Medical Center, Albinusdreef 2, Leiden 2333 ZA, The Netherlands
    J Magn Reson 216:107-13. 2012
  8. doi request reprint Increasing the sensitivity of magnetic resonance spectroscopy and imaging
    Andrew Webb
    C J Gorter Center for High Field Magnetic Resonance Imaging, Department of Radiology, Leiden University Medical Center, Leiden ZA 2333, The Netherlands
    Anal Chem 84:9-16. 2012
  9. doi request reprint 7 T MRI reveals diffuse iron deposition in putamen and caudate nucleus in CADASIL
    Michael K Liem
    Department of Radiology, Leiden University Medical Center, C2S, Albinusdreef 2, 2333ZA Leiden, The Netherlands
    J Neurol Neurosurg Psychiatry 83:1180-5. 2012
  10. pmc Right coronary MR angiography at 7 T: a direct quantitative and qualitative comparison with 3 T in young healthy volunteers
    Saskia G C van Elderen
    Department of Radiology, Leiden University Medical Center, Albinusdreef 2, Leiden, The Netherlands
    Radiology 257:254-9. 2010

Collaborators

Detail Information

Publications45

  1. doi request reprint Improved signal to noise in proton spectroscopy of the human calf muscle at 7 T using localized B1 calibration
    Maarten J Versluis
    Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
    Magn Reson Med 63:207-11. 2010
    ..This new technique was able to measure the inhomogeneous radiofrequency field at 7 T and its use resulted in a considerable signal-to-noise ratio increase...
  2. pmc MRI and localized proton spectroscopy in human leg muscle at 7 Tesla using longitudinal traveling waves
    Andrew G Webb
    C J Gorter Center for High Field Magnetic Resonance Imaging, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
    Magn Reson Med 63:297-302. 2010
    ..If a local receive coil is used in combination with the remote transmit coil, then the signal-to-noise improves significantly, as expected...
  3. doi request reprint Evaluation of plasma-based transmit coils for magnetic resonance
    A G Webb
    C J Gorter Center for High Field MRI, Leiden University Medical Center, The Netherlands Electronic address
    J Magn Reson 261:49-53. 2015
    ....
  4. doi request reprint Cavity- and waveguide-resonators in electron paramagnetic resonance, nuclear magnetic resonance, and magnetic resonance imaging
    Andrew Webb
    C J Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands Electronic address
    Prog Nucl Magn Reson Spectrosc 83:1-20. 2014
    ..Applications in EPR and MRI are summarized, and finally the topic of traveling wave MRI using the magnet bore as a waveguide is discussed. ..
  5. pmc Detectability of absorption and reduced scattering coefficients in frequency-domain measurements using a realistic head phantom
    Xiaofeng Zhang
    Department of Radiology, Duke University Medical Center, DUMC 3808, Durham, NC 27710, USA
    Sensors (Basel) 13:152-64. 2013
    ..The phase delay, which can be used to quantify the fast neuronal optical response in the human brain, showed a linear dependence on the reciprocal of the reduced scattering coefficient, as predicted by the Rytov approximation...
  6. doi request reprint Radiofrequency microcoils for magnetic resonance imaging and spectroscopy
    A G Webb
    C J Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
    J Magn Reson 229:55-66. 2013
    ..This review concentrates on recent developments in the construction of single and multiple RF microcoil systems, and new types of experiments that can be performed using such assemblies...
  7. doi request reprint Visualization and characterization of pure and coupled modes in water-based dielectric resonators on a human 7T scanner
    A G Webb
    Department of Radiology, C3 Q, Leiden University Medical Center, Albinusdreef 2, Leiden 2333 ZA, The Netherlands
    J Magn Reson 216:107-13. 2012
    ..In addition, coupled modes between more than one resonator were investigated, with possible future applications including direct visualization of fields in metamaterials...
  8. doi request reprint Increasing the sensitivity of magnetic resonance spectroscopy and imaging
    Andrew Webb
    C J Gorter Center for High Field Magnetic Resonance Imaging, Department of Radiology, Leiden University Medical Center, Leiden ZA 2333, The Netherlands
    Anal Chem 84:9-16. 2012
    ....
  9. doi request reprint 7 T MRI reveals diffuse iron deposition in putamen and caudate nucleus in CADASIL
    Michael K Liem
    Department of Radiology, Leiden University Medical Center, C2S, Albinusdreef 2, 2333ZA Leiden, The Netherlands
    J Neurol Neurosurg Psychiatry 83:1180-5. 2012
    ..The aim of this study is to quantify diffuse iron deposition in patients with the hereditary small vessel disease cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)...
  10. pmc Right coronary MR angiography at 7 T: a direct quantitative and qualitative comparison with 3 T in young healthy volunteers
    Saskia G C van Elderen
    Department of Radiology, Leiden University Medical Center, Albinusdreef 2, Leiden, The Netherlands
    Radiology 257:254-9. 2010
    ..To objectively compare quantitative parameters related to image quality attained at coronary magnetic resonance (MR) angiography of the right coronary artery (RCA) performed at 7 T and 3 T...
  11. doi request reprint Evaluation of signal formation in local arterial input function measurements of dynamic susceptibility contrast MRI
    Egbert J W Bleeker
    Department of Radiology, CJ Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, The Netherlands
    Magn Reson Med 67:1324-31. 2012
    ..These findings are suggesting that local AIF measurements do not necessarily reflect the true concentration-time curve in small arteries...
  12. doi request reprint Cortical phase changes in Alzheimer's disease at 7T MRI: a novel imaging marker
    Sanneke van Rooden
    C J Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, The Netherlands Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands Electronic address
    Alzheimers Dement 10:e19-26. 2014
    ..The aim of this study is to test this hypothesis in patients with Alzheimer's disease (AD)...
  13. doi request reprint 7T T₂*-weighted magnetic resonance imaging reveals cortical phase differences between early- and late-onset Alzheimer's disease
    Sanneke van Rooden
    C J Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, The Netherlands Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands Electronic address
    Neurobiol Aging 36:20-6. 2015
    ..042). These data suggest that EOAD patients have an increased iron accumulation, possibly related to an increased amyloid deposition, in specific cortical regions as compared with LOAD patients...
  14. doi request reprint Texture analysis of ultrahigh field T2*-weighted MR images of the brain: application to Huntington's disease
    Nhat Trung Doan
    Division of Image Processing LKEB, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
    J Magn Reson Imaging 39:633-40. 2014
    ..To develop a framework for quantitative detection of between-group textural differences in ultrahigh field T2*-weighted MR images of the brain...
  15. doi request reprint Elevated brain iron is independent from atrophy in Huntington's Disease
    Eve M Dumas
    Department of Neurology, Leiden University Medical Center, The Netherlands
    Neuroimage 61:558-64. 2012
    ..We have demonstrated that the iron content of these structures relates to disease state in gene carriers, independently of the measured volume of these structures...
  16. doi request reprint MR microscopy of human amyloid-β deposits: characterization of parenchymal amyloid, diffuse plaques, and vascular amyloid
    Rob J A Nabuurs
    Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
    J Alzheimers Dis 34:1037-49. 2013
    ..These findings are relevant for the interpretation and further development of (quantitative) MRI methods for the detection and follow-up of AD and CAA...
  17. doi request reprint Differences in apparent diffusion coefficients of brain metabolites between grey and white matter in the human brain measured at 7 T
    Hermien E Kan
    CJ Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
    Magn Reson Med 67:1203-9. 2012
    ..These differences can probably be attributed to different compartmentalization as well as to the differential impact of diffusion time on ADC of different molecules under conditions of restricted diffusion...
  18. doi request reprint Quantitative assessment of left ventricular function in humans at 7 T
    Anne Brandts
    Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
    Magn Reson Med 64:1471-7. 2010
    ..In conclusion, this study shows that assessing left ventricular volumes, function, and flow is feasible at 7 T MRI and that standardized MRI protocols provide similar quantitative results when compared with 1.5 T MRI...
  19. doi request reprint Increased number of microinfarcts in Alzheimer disease at 7-T MR imaging
    Sanneke van Rooden
    From the C J Gorter Center for High Field Strength MRI S v R, A M v O, M J V, A G W, M A v B, J v d G, Department of Radiology S v R, A M v O, M J V, A G W, M A v B, J v d G, and Department of Gerontology and Geriatrics G J B, Leiden University Medical Center, PO Box 9600, C3 Q, 2300 RC Leiden, The Netherlands Alzheimer Center and Department of Neurology, Neuroscience Campus Amsterdam, Amsterdam, the Netherlands J D C G, W M v d F, P S Departments of Radiology F B and Epidemiology and Biostatistics W M v d F, VU University Medical Center, Amsterdam, the Netherlands and Department of Gerontology and Geriatrics, Bronovo Hospital, Den Haag, the Netherlands G J B
    Radiology 270:205-11. 2014
    ....
  20. doi request reprint Combined magnitude and phase-based segmentation of the cerebral cortex in 7T MR images of the elderly
    Nhat Trung Doan
    Division of Image Processing, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
    J Magn Reson Imaging 36:99-109. 2012
    ..To propose a new method that integrates both magnitude and phase information obtained from magnetic resonance (MR) T*(2) -weighted scans for cerebral cortex segmentation of the elderly...
  21. doi request reprint New criterion to aid manual and automatic selection of the arterial input function in dynamic susceptibility contrast MRI
    Egbert J W Bleeker
    Department of Radiology, C J Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, The Netherlands
    Magn Reson Med 65:448-56. 2011
    ..The data showed that the new criterion enables detection of shape errors, although false positives do occur, which could be easily avoided when combined with current AIF selection criteria...
  22. doi request reprint Improved Cardiac Proton Magnetic Resonance Spectroscopy at 3 T Using High Permittivity Pads
    Paul de Heer
    From the C J Gorter Center for High Field MRI, and Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
    Invest Radiol 51:134-8. 2016
    ..The aim of this study was to determine whether high permittivity (HP) pads can be used to increase the signal-to-noise ratio (SNR) of cardiac proton magnetic resonance spectroscopy at 3 T, allowing faster data acquisition...
  23. doi request reprint Subject tolerance of 7 T MRI examinations
    Maarten J Versluis
    C J Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
    J Magn Reson Imaging 38:722-5. 2013
    ..To determine the subjective experiences and the sources of discomfort for subjects undergoing 7 T magnetic resonance imaging (MRI) examinations on a whole-body 7 T system in a hospital setting..
  24. doi request reprint High-field MRI of single histological slices using an inductively coupled, self-resonant microcoil: application to ex vivo samples of patients with Alzheimer's disease
    Rob J A Nabuurs
    Department of Radiology, C J Gorter Center for High Field MRI, Leiden University Medical Center, The Netherlands
    NMR Biomed 24:351-7. 2011
    ..An example is shown of ex vivo samples from patients with Alzheimer's disease, in which the coregistration of highly sensitive iron staining and amyloid-β deposits is confirmed...
  25. doi request reprint Design and evaluation of a detunable water-based quadrature HEM11 mode dielectric resonator as a new type of volume coil for high field MRI
    Sebastian A Aussenhofer
    Department of Radiology, C J Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, The Netherlands
    Magn Reson Med 68:1325-31. 2012
    ....
  26. doi request reprint Diffusion-weighted chemical shift imaging of human brain metabolites at 7T
    Ayse Ece Ercan
    C J Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands
    Magn Reson Med 73:2053-61. 2015
    ....
  27. doi request reprint Time-efficient interleaved human (23)Na and (1)H data acquisition at 7 T
    Paul W de Bruin
    Radiology Department, Leiden University Medical Center, The Netherlands
    NMR Biomed 28:1228-35. 2015
    ..This approach for the interleaving of multiple proton and sodium scans, each with different contrasts, is an efficient method for the design of new practical clinical protocols for sodium MRI...
  28. doi request reprint Exercise and type 2 diabetes mellitus: changes in tissue-specific fat distribution and cardiac function
    Jacqueline T Jonker
    Departments of Endocrinology and Metabolism, Radiology, and Nephrology, Leiden University Medical Center, C3 R, Albinusdreef 2, PO Box 9600, 2300 RC Leiden, The Netherlands Department of Internal Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands Department of Cardiology, Tjongerschans Hospital, Heerenveen, The Netherlands Department of Internal Medicine, University Medical Center Groningen, Groningen, The Netherlands
    Radiology 269:434-42. 2013
    ..To prospectively assess the effects of an exercise intervention on organ-specific fat accumulation and cardiac function in type 2 diabetes mellitus...
  29. doi request reprint Quantitative assessment of the effects of high-permittivity pads in 7 Tesla MRI of the brain
    Wouter M Teeuwisse
    CJ Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
    Magn Reson Med 67:1285-93. 2012
    ....
  30. doi request reprint Magnetic resonance compatibility of intraocular lenses measured at 7 Tesla
    Gwyneth A van Rijn
    Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands
    Invest Ophthalmol Vis Sci 53:3449-53. 2012
    ..To determine whether intraocular lenses (IOLs) are compatible with magnetic resonance imaging (MRI) at a magnetic field strength of 7 Tesla, the highest field strength at which clinical MRI scans are performed...
  31. pmc Feasibility of pseudocontinuous arterial spin labeling at 7 T with whole-brain coverage
    Eidrees Ghariq
    Department of Radiology, C J Gorter Center for High Field MRI, Leiden University Medical Center LUMC, C3 Q, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
    MAGMA 25:83-93. 2012
    ..We studied the feasibility of pseudocontinuous arterial spin labeling (pCASL) at 7 T...
  32. doi request reprint Phase-based arterial input function measurements for dynamic susceptibility contrast MRI
    Egbert J W Bleeker
    C J Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
    Magn Reson Med 64:358-68. 2010
    ..Third, phase-based AIF selection allows more locations in tissue to be chosen that show the correct AIF than does magnitude-based AIF selection...
  33. doi request reprint Initial results on in vivo human coronary MR angiography at 7 T
    Saskia G C van Elderen
    Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
    Magn Reson Med 62:1379-84. 2009
    ..With this methodology, the first human coronary MR images were successfully obtained at 7 T, with both qualitative and quantitative findings being presented...
  34. doi request reprint MR of multi-organ involvement in the metabolic syndrome
    Maurice B Bizino
    Department of Radiology, Leiden University Medical Center, Albinusdreef 2, Leiden 2333 ZA, The Netherlands Electronic address
    Magn Reson Imaging Clin N Am 23:41-58. 2015
    ..Various other organs can be assessed with MR. MR is a powerful tool to unravel whole-body MetS pathophysiology, monitor therapeutic efficacy, and establish prognosis. ..
  35. doi request reprint High permittivity dielectric pads improve high spatial resolution magnetic resonance imaging of the inner ear at 7 T
    Wyger M Brink
    From the C J Gorter Center for High Field MRI, Department of Radiology, Department of Otorhinolaryngology Head and Neck Surgery, Leiden University Medical Center, Leiden, and Department of Radiology, Leiden University Medical Center, Leiden and Radboud University Medical Center, Nijmegen, The Netherlands
    Invest Radiol 49:271-7. 2014
    ..The objective of this study was to evaluate the use of dielectric pads for improving high spatial resolution imaging of the inner ear at 7 T...
  36. doi request reprint High spatial resolution coronary magnetic resonance angiography at 7 T: comparison with low spatial resolution bright blood imaging
    Maurice B Bizino
    From the Departments of Radiology and Cardiology, Leiden University Medical Center, Leiden, The Netherlands
    Invest Radiol 49:326-30. 2014
    ..The aim of this study was to compare bright blood high spatial resolution (HR) coronary magnetic resonance angiography (MRA) with low spatial resolution (LR) bright blood coronary MRA at 7 T...
  37. doi request reprint Ultrahigh-field 7-T magnetic resonance carotid vessel wall imaging: initial experience in comparison with 3-T field strength
    Eleanore S J Kröner
    Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands
    Invest Radiol 47:697-704. 2012
    ....
  38. doi request reprint Lenticulostriate arterial lumina are normal in cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy: a high-field in vivo MRI study
    Michael K Liem
    Department of Radiology, Leiden University Medical Center, ZA Leiden, The Netherlands
    Stroke 41:2812-6. 2010
    ..The aim of this study is to examine the luminal diameters of lenticulostriate arteries in living patients with CADASIL and to investigate whether luminal narrowing is correlated with the number of lacunar infarcts in the basal ganglia...
  39. doi request reprint Diffusion-prepared neurography of the brachial plexus with a large field-of-view at 3T
    Jos Oudeman
    Department of Radiology, Academic Medical Center, Amsterdam, The Netherlands
    J Magn Reson Imaging 43:644-54. 2016
    ..The aim was therefore to find an optimal (combination of) shimming method(s) for diffusion-prepared neurography in a large FOV...
  40. pmc The effect of high-permittivity pads on specific absorption rate in radiofrequency-shimmed dual-transmit cardiovascular magnetic resonance at 3T
    Wyger M Brink
    C J Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
    J Cardiovasc Magn Reson 17:82. 2015
    ....
  41. doi request reprint Clinical applications of dual-channel transmit MRI: A review
    Wyger M Brink
    C J Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
    J Magn Reson Imaging 42:855-69. 2015
    ..Future advances in transmit SENSE, the combination of dual-channel transmit with high permittivity pads, as well as the potential increase in the number of transmit channels are also discussed...
  42. doi request reprint Automated retinal topographic maps measured with magnetic resonance imaging
    Jan Willem M Beenakker
    Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands Department of Radiology, C J Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, The Netherlands
    Invest Ophthalmol Vis Sci 56:1033-9. 2015
    ..We describe a new magnetic resonance imaging (MRI)-based method to obtain the retinal shape with high precision and use it to assess if differences in retinal shape could explain previously described trends in peripheral refraction...
  43. doi request reprint Ventricular B1 (+) perturbation at 7 T - real effect or measurement artifact?
    Wyger M Brink
    C J Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
    NMR Biomed 27:617-20. 2014
    ....
  44. doi request reprint High permittivity pads reduce specific absorption rate, improve B1 homogeneity, and increase contrast-to-noise ratio for functional cardiac MRI at 3 T
    Wyger M Brink
    Department of Radiology, C J Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, The Netherlands
    Magn Reson Med 71:spcone. 2014
    ..To improve image quality and reduce specific absorption rate in functional cardiac imaging at 3 T...
  45. doi request reprint High permittivity pads reduce specific absorption rate, improve B1 homogeneity, and increase contrast-to-noise ratio for functional cardiac MRI at 3 T
    Wyger M Brink
    Department of Radiology, C J Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, The Netherlands
    Magn Reson Med 71:1632-40. 2014
    ..To improve image quality and reduce specific absorption rate in functional cardiac imaging at 3 T...