Keywords

• MR Spectroscopy
• Imaging of other nuclei
• Matlab programming for
  • Image analysis,
  • Simulation of relaxation and chemical exchange,
  • RF pulse development,
  • Image reconstruction for non uniform sampled k-space.

Hobbies

• Cycling
• Remodelling
• Loudspeakers

Education

Professional Experience

Published Works

1. van Paridon, P.A., de Kruijff, B., Ouwerkerk R . and  Wirtz, K.W.A, Polyphosphoinositides undergo charge neutralization in the physiological pH range: a 31 P-NMR study. Biochimica Biophysica Acta 877 (1986), 216-219.
2. Ouwerkerk, R ., van Echteld, C .J.A.,  Staal, G.E.J. and Rijksen, G., Distribution of phosphorylated metabolites and magnesium in the red cells of a patient with hyperactive pyruvate kinase. Blood 72 (1988), 1224-1229.
3. Ouwerkerk, R. , van Echteld, C .J.A.,  Staal, G.E.J. and Rijksen, G., Intracellular free magnesium and phosphorylated metabolites in hexokinase and pyruvate kinase deficient red cells measured using 31 P-NMR spectroscopy. Biochimica Biophysica Acta 1010 (1989), 294-303.
4. Ouwerkerk, R ., Damen, P., de Haan, K.,  Staal, G.E.J. and Rijksen, G., Hexose monophosphate shunt activity in erythrocytes related to cell age. European Journal of Haematology 43 (1989), 441-447.
5. Ouwerkerk, R ., van Echteld, C .J.A.,  Staal, G.E.J. and Rijksen, G., Erythrocyte Na +/K +ATPase activity measured with 23 Na-NMR. Magnetic Resonance in Medicine 12 (1989), 164-171.
6. Conway, M.A., Allis, J., Ouwerkerk, R ., Niioka, T., Rajagopalan, B. and Radda, G.K., Detection of low Phosphocreatine to ATP ratio in Failing hypertrophied human myocardium by 31 P magnetic resonance spectroscopy. Lancet 338 (1991), 973-976.
7. J. Moorcraft, J., Bolas, N.M.,  Ives, N.K., Ouwerkerk, R ., Smyth, J., Rajagopalan, B., Hope, P.L., and Radda, G.K., Global and depth resolved phosporous magnetic resonance spectroscopy to predict outcome after birth asphyxia, Archives of Disease in Childhood 66 (1991), 1119-1123.
8. Jones, J.A., Hore, P.J., Relf, C.P., Ouwerkerk R. and Styles, P., Supression of artefacts in the phase-modulated rotating frame imaging experiment using the maximum entropy method. Journal of Magnetic Resonance 98 (1992), 73-80.
9. M.A. Conway, J. Allis, R. Ouwerker k, B. Rajagopalan and G.K. Radda. Low phosphocreatine/ATP detected in vivo in the failing human hypertrophied myocardium by 31 P magnetic resonance spectroscopy. British Heart Journal 66 (1991), 107P (Abstract)
10. M.A. Conway, R. Ouwerker k, J. Allis, T. Niioka, J.C. Forfar, G.K. Radda. Low levels of high energy phosphorus metabolites detected by 31 P magnetic resonance spectroscopy in the human heart damaged by myocarditis and ischaemic cardiomyopathy. European Heart Journal 12 (Supp) (1991), 38.
11. Conway, M.A., Ouwerkerk, R ., Allis, J. , Rajagopalan, B., and Radda, G.K., Low phosphocreatine/ATP detected by 31 P NMR in the myocardium of patients with heart failure due to severe valve disease. Circulation 84 (Supp II) (1991), 379.
12. Conway, M.A., Ouwerkerk, R ., Rajagopalan, B., and Radda, G.K.,. Myocardial hypertrophy in valvular heart disease and hypertension: low PCr/ATP in patients with compensated heart failure. J Am Coll Cardiol. 1992
13. Brooke, N.S., Ouwerkerk, R ., C.B.T. Adams, C.B.T., Radda, G.K., Ledingham, J.G.G. and Rajagopalan, B., 31 Phosphorous magnetic resonance spectra reveal prolonged intracellular acidosis in the brain following subarachnoid haemorrhage. 11 th Meeting of the Society of Magnetic Resonance in Medicine Book of Abstracts (1992) P 1915
14. Brooke, N.S., Ouwerkerk, R. , C.B.T. Adams, C.B.T., Radda, G.K., Ledingham, J.G.G. and Rajagopalan, B., 31 Phosphorous magnetic resonance spectra reveal changes in pH in raised intracranial pressure secondary to hydrocephalus pre & post treatment. 11 th Meeting of the Society of Magnetic Resonance in Medicine Book of Abstracts (1992) P 1916
15. Conway, M.A., Ouwerkerk, R ., Rajagopalan, B., and Radda, G.K., 31 P phase modulated rotating frame imaging (PMRFI) spectroscopy of thickened and dilated hearts due to hypertension, valvular and myocardial disease. 11 th Meeting of the Society of Magnetic Resonance in Medicine Book of Abstracts (1992) P 2304
16. Miall-Allen, V.M., Adatia, I., Kemp, G.J. Taylor, D.J., Ouwerkerk, R ., Rajagopalan, B., Haworth S.G., and Radda, G.K.. Skeletal muscle pH and bioenergetics in the chronic hypoxia of cyanotic congenital heart disease. 11 th Meeting of the Society of Magnetic Resonance in Medicine Book of Abstracts (1992) P 1915
17. Brooke, N.S., Ouwerkerk, R. , C.B.T. Adams, C.B.T., Radda, G.K., Ledingham, J.G.G. and Rajagopalan, B., 31 Phosphorous Magnetic Resonance Spectroscopy- A new method for detecting cerebral ischemia in subarachnoid heamorrage. in: Management of Cerebro-Vascular Malformations International Conference, Book of Abstracts (1992)
18. Bottomley, P.A.  and Ouwerkerk, R. , BIRP, an Improved Implementation of Low-Angle Adiabatic (BIR-4) Excitation Pulses. Journal of Magnetic Resonance, Series A, (1993) 103 , 242-244.
    Ouwerkerk, R. and Radda, G.K.. Calculation of metabolite ratios from in-vivo NMR data with imperfect spatial resolution by means of Singular Value Decomposition. 12 th Meeting of the Society of Magnetic Resonance in Medicine Book of Abstracts (1993) P 728.
19. Bottomley, P.A.  and Ouwerkerk, R. , Efficient new T 1measurement method employing low-angle adiabatic pulses. 12 th Meeting of the Society of Magnetic Resonance in Medicine Book of Abstracts (1993) P 1209.
20. Conway, M.A., Ouwerkerk, R. , and Radda, G.K., 31 P Magnetic resonance Spectroscopy in Hypertrophy and Heart Failure. in: Cardiovascular Applications of Magnetic Resonance. (G.M. Pohost ed.), Mount Kisco, N.Y., Futura Publishing Co., Inc., (1993) p 341-347.
21. Smyth, J.P., Hope, P.L., Dixon, R.M., Ouwerkerk, R. , Rajagopalan, R. and Radda, G.K.. 31 P Magnetic Resonance Spectroscopy of the Liver in an Infant with Galactosemia. accepted for publication in MAGMA 3rd issue (1993).
22. Bottomley, P.A.  and Ouwerkerk, R. , The Dual-Angle Method for Fast, Sensitive T 1Measurement in-Vivo with Low-Angle Adiabatic Pulses. Journal of Magnetic Resonance Series B 104 , 159-167 (1994).
23. Brooke, N.S., Ouwerkerk, R. Adams, C.B.T., Radda G.K., Ledingham, J.G.G. and Rajagopalan, B., P-31 Magnetic-Resonance Spectra Reveal Prolonged Intracellular Acidosis in the Brain Following Subarachnoid Hemorrhage. Proceedings of the National Academy of Science U.S.A. 91 , 1903-1907 (1994).
24. Bottomley, P.A. and Ouwerkerk, R. Optimum Flip-Angles for Exciting NMR with Uncertain T-1 Values. Magnetic Resonance in Medicine 32, 137-141 (1994).
25. Ouwerkerk, R. , van Echteld, C.J.A. Chemical exchange and observed human cardiac PCr/ATP ratios: a short fully relaxed experiment for measurement of the true ratio 4th Meeting of the International Society of Magnetic Resonance in Medicine Book of Abstracts p1012 (1996)
26. Lamb, H.J., Ouwerkerk, R. , Doornbos, J., van der Laarse, A. and de Roos, A. Motion sensitivity od 3D-ISIS: effects on human cardiac 31P-MRS during stress. 5th Meeting of the International Society of Magnetic Resonance in Medicine Book of Abstracts p1012 (1997)
27. Ronald Ouwerkerk. Spectroscopy Application Guide. Philips Medical Systems MR, Best, the Netherlands (1997)
28. Lamb HJ, Beyerbacht HP, Ouwerkerk R , Doornbos J, Pluim BM, van der Wall EE, van der Laarse A, de Roos A. Metabolic response of normal human myocardium to high-dose atropine-dobutamine stress studied by 31P-MRS. Circulation 96, 2969-77 (1997).
29. Ouwerkerk, R. Lamb, H.J. van Echteld, C.J.A. More efficient and accurate methods for measuring human cardiac PCr /ATP ratios: benefits of chemical exchange. 6th Meeting of the International Society of Magnetic Resonance in Medicine Book of Abstracts . P1814 (1998).
30. Conway, M.A., Bottomley P.A., Ouwerkerk R ., Radda G.K., Rajagopalan B. Mitral regurgitation: impaired systolic function, eccentric hypertrophy, and increased severity are linked to lower phosphocreatine/ATP ratios in humans. Circulation. 97:1716-23 (1998).
31. Ouwerkerk R ., Lee R.F., and Bottomley P.A Dynamic changes in sodium levels in human exercising muscle measured with 23Na MRI. 7th Meeting of the International Society of Magnetic Resonance in Medicine Book of Abstracts. p1530  (1999).
32. Bottomley P.A., Weiss R.G., Lee R.F., and Ouwerkerk, R . Quantification of human myocardial phosphorous, proton and sodium metabolites 3rd Annual Scientific Session of the Society for Cardiovascuar Magnetic Resonance (2000).
33. Ouwerkerk R ., Lee R.F., Weiss R.G. and Bottomley P.A. A new FAST method for in-vivo measurement of chemical exchange rates 8th Meeting of the International Society of Magnetic Resonance in Medicine Book of Abstracts. p421  (2000).
34. Peter B. Barker, Xavier Golay, Dmitri Artemov, Ronald Ouwerkerk , Mari A. Smith, and A.J. Shaka Broadband Proton Decoupling for In Vivo Brain Spectroscopy in Humans Mag. Res. Med. 45:226-232 (2001)
35. Ouwerkerk, R ., and Bottomley P.A. On neglecting chemical exchange effects when correcting in-vivo 31P MRS data for partial saturation. Journal of Magnetic Resonance 148, 425-435 (2001)
36. Ouwerkerk, R., and Bottomley P.A. On Neglecting Chemical Exchange When Correcting in Vivo 31 P MRS Data for Partial Saturation: Commentary on: “Pitfalls in the Measurement of Metabolite Concentrations Using the One-Pulse Experiment in in VivoNMR” Journal of Magnetic Resonance 149, 282–286 (2001)
37. Bottomley, P.A., Ouwerkerk, R., Lee, R.F. and Weiss, R.G.. Four Angle saturation Transfer (FAST) Method for Measuring Creatine Kinase Reaction rates In Vivo. Magnetic Resonance in Medicine, 2002. 47: p. 850-663.
38. Ouwerkerk R, Bleich KB, Gillen JS, Pomper MG, Bottomley PA, Tissue Sodium Concentration in Human Brain Tumors as Measured with 23Na MR Imaging. Radiology 2003;227:529-537
39. Ouwerkerk R, Weiss, R.G. and Bottomley PA, Measuring Human Cardiac Tissue Sodium Concentrations Using Surface Coils, Adiabatic Excitation, and Twisted Projection Imaging with Minimal T2 Losses. Journal of Magnetic Resonance Imaging 2005;21(5):546-555
40. Naumova, A.V., Chacko, V.P., Ouwerkerk, R., Stull, L., Marbán, E., Weiss, R.G. Xanthine Oxidase Inhibitors Improve Energetics and Function Following Infarction in the Failing Mouse Heart., American Journal of Physiology 2006, 290: H837-H843
41. Gabr RE, Ouwerkerk R, Bottomley PA. Quantifying in vivo MR spectra with circles. J Magn Reson 2006;179(1):152-63.
42. Nezafat R, Stuber M, Ouwerkerk R, Gharib AM, Desai MY, Pettigrew RI. B1-insensitive T2 preparation for improved coronary magnetic resonance angiography at 3 T. Magn Reson Med 2006;55(4):858-64.
43. Macura KJ, Ouwerkerk R, Jacobs MA, Bluemke DA. Patterns of Enhancement on Breast MR Images: Interpretation and Imaging Pitfalls. Radiographics. 2006 Nov-Dec;26(6):1719-34.
44. Jacobs MA, Ibrahim TS, Ouwerkerk R. AAPM/RSNA physics tutorials for residents: MR imaging: brief overview and emerging applications. Radiographics 2007;27(4):1213-1229.
45. Ouwerkerk R, Jacobs MA, Macura KJ, Wolff AC, Stearns V, Mezban SD, Khouri NF, Bluemke DA, Bottomley PA. Elevated tissue sodium concentration in malignant breast lesions detected with non-invasive Na-23 MRI. Breast Cancer Research and Treatment 2007;106(2):151-160.
46. Ouwerkerk R. Sodium magnetic resonance imaging: from research to clinical use. J Am Coll Radiol 2007;4(10):739-741.

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