Rohan Dharmakumar

Summary

Affiliation: Northwestern University
Country: USA

Publications

  1. doi request reprint Assessment of regional myocardial oxygenation changes in the presence of coronary artery stenosis with balanced SSFP imaging at 3.0 T: theory and experimental evaluation in canines
    Rohan Dharmakumar
    Department of Radiology, Northwestern University, Chicago, Illinois 60611, USA
    J Magn Reson Imaging 27:1037-45. 2008
  2. pmc Oxygenation-sensitive CMR for assessing vasodilator-induced changes of myocardial oxygenation
    Matthias Vöhringer
    Stephenson Cardiovascular MR Centre at the Libin Cardiovascular Institute of Alberta, Department of Cardiac Sciences, University of Calgary, Calgary, AB, Canada
    J Cardiovasc Magn Reson 12:20. 2010
  3. ncbi request reprint Dual-contrast cellular magnetic resonance imaging
    Rohan Dharmakumar
    Department of Radiology, Northwestern University, Chicago, IL, USA
    Mol Imaging 8:254-63. 2009
  4. ncbi request reprint Generating positive contrast from off-resonant spins with steady-state free precession magnetic resonance imaging: theory and proof-of-principle experiments
    Rohan Dharmakumar
    Department of Radiology, Northwestern University, Suite 700, 448 E Ontario St, Chicago, IL 60611, USA
    Phys Med Biol 51:4201-15. 2006
  5. ncbi request reprint Cardiac phase-resolved blood oxygen-sensitive steady-state free precession MRI for evaluating the functional significance of coronary artery stenosis
    Rohan Dharmakumar
    Department of Radiology, Northwestern University, Chicago, IL 60611, USA
    Invest Radiol 42:180-8. 2007
  6. ncbi request reprint Factors influencing fast low angle positive contrast steady-state free precession (FLAPS) magnetic resonance imaging
    Rohan Dharmakumar
    Department of Radiology, Northwestern University, Chicago, IL, USA
    Phys Med Biol 52:3261-73. 2007
  7. pmc Detecting myocardial ischemia at rest with cardiac phase-resolved blood oxygen level-dependent cardiovascular magnetic resonance
    Sotirios A Tsaftaris
    Departments of Radiology, Northwestern University, Chicago, IL, USA
    Circ Cardiovasc Imaging 6:311-9. 2013
  8. doi request reprint On the mechanisms enabling myocardial edema contrast in bSSFP-based imaging approaches
    Xiangzhi Zhou
    Department of Radiology, Northwestern University, Chicago, Illinois, USA
    Magn Reson Med 66:187-91. 2011
  9. doi request reprint T(2) -weighted STIR imaging of myocardial edema associated with ischemia-reperfusion injury: the influence of proton density effect on image contrast
    Xiangzhi Zhou
    Department of Radiology, Northwestern University, Chicago, IL, USA
    J Magn Reson Imaging 33:962-7. 2011
  10. pmc Artifact-reduced two-dimensional cine steady state free precession for myocardial blood- oxygen-level-dependent imaging
    Xiangzhi Zhou
    Department of Radiology, Northwestern University, Chicago, Illinois 60611, USA
    J Magn Reson Imaging 31:863-71. 2010

Collaborators

Detail Information

Publications23

  1. doi request reprint Assessment of regional myocardial oxygenation changes in the presence of coronary artery stenosis with balanced SSFP imaging at 3.0 T: theory and experimental evaluation in canines
    Rohan Dharmakumar
    Department of Radiology, Northwestern University, Chicago, Illinois 60611, USA
    J Magn Reson Imaging 27:1037-45. 2008
    ..To examine the dependence of steady-state free-precession (SSFP) -based myocardial blood-oxygen-level-dependent (BOLD) contrast on field strength using theoretical and experimental models...
  2. pmc Oxygenation-sensitive CMR for assessing vasodilator-induced changes of myocardial oxygenation
    Matthias Vöhringer
    Stephenson Cardiovascular MR Centre at the Libin Cardiovascular Institute of Alberta, Department of Cardiac Sciences, University of Calgary, Calgary, AB, Canada
    J Cardiovasc Magn Reson 12:20. 2010
    ....
  3. ncbi request reprint Dual-contrast cellular magnetic resonance imaging
    Rohan Dharmakumar
    Department of Radiology, Northwestern University, Chicago, IL, USA
    Mol Imaging 8:254-63. 2009
    ..The technique substantially improves the ability of MRI for detecting labeled cells by overcoming the fundamental limits that currently plague negative contrast methods...
  4. ncbi request reprint Generating positive contrast from off-resonant spins with steady-state free precession magnetic resonance imaging: theory and proof-of-principle experiments
    Rohan Dharmakumar
    Department of Radiology, Northwestern University, Suite 700, 448 E Ontario St, Chicago, IL 60611, USA
    Phys Med Biol 51:4201-15. 2006
    ..Among practical applications, we anticipate that the proposed technique can potentially facilitate high field magnetic-resonance-based molecular imaging...
  5. ncbi request reprint Cardiac phase-resolved blood oxygen-sensitive steady-state free precession MRI for evaluating the functional significance of coronary artery stenosis
    Rohan Dharmakumar
    Department of Radiology, Northwestern University, Chicago, IL 60611, USA
    Invest Radiol 42:180-8. 2007
    ....
  6. ncbi request reprint Factors influencing fast low angle positive contrast steady-state free precession (FLAPS) magnetic resonance imaging
    Rohan Dharmakumar
    Department of Radiology, Northwestern University, Chicago, IL, USA
    Phys Med Biol 52:3261-73. 2007
    ....
  7. pmc Detecting myocardial ischemia at rest with cardiac phase-resolved blood oxygen level-dependent cardiovascular magnetic resonance
    Sotirios A Tsaftaris
    Departments of Radiology, Northwestern University, Chicago, IL, USA
    Circ Cardiovasc Imaging 6:311-9. 2013
    ..This study investigated the use of cardiac phase-resolved blood oxygen level-dependent (CP-BOLD) cardiovascular magnetic resonance in detecting myocardial ischemia at rest secondary to severe coronary artery stenosis...
  8. doi request reprint On the mechanisms enabling myocardial edema contrast in bSSFP-based imaging approaches
    Xiangzhi Zhou
    Department of Radiology, Northwestern University, Chicago, Illinois, USA
    Magn Reson Med 66:187-91. 2011
    ..05). Hence the acquisition strategies that wish to maximize myocardial edema contrast in cine bSSFP imaging should take both relaxation and M(0) effects into account...
  9. doi request reprint T(2) -weighted STIR imaging of myocardial edema associated with ischemia-reperfusion injury: the influence of proton density effect on image contrast
    Xiangzhi Zhou
    Department of Radiology, Northwestern University, Chicago, IL, USA
    J Magn Reson Imaging 33:962-7. 2011
    ..To investigate the contribution of proton density (PD) in T(2) -STIR based edema imaging in the setting of acute myocardial infarction (AMI)...
  10. pmc Artifact-reduced two-dimensional cine steady state free precession for myocardial blood- oxygen-level-dependent imaging
    Xiangzhi Zhou
    Department of Radiology, Northwestern University, Chicago, Illinois 60611, USA
    J Magn Reson Imaging 31:863-71. 2010
    ..To minimize image artifacts in long TR cardiac phase-resolved steady state free precession (SSFP) based blood-oxygen-level-dependent (BOLD) imaging...
  11. pmc Fast low-angle positive contrast steady-state free precession imaging of USPIO-labeled macrophages: theory and in vitro experiment
    Nicole Mascheri
    Department of Biomedical Engineering, Northwestern University, Chicago, IL, USA
    Magn Reson Imaging 27:961-9. 2009
    ..Results suggest that USPIO-labeled macrophages are capable of producing the conditions necessary for positive contrast with FLAPS at clinical field strength (1.5 T) and resolution (0.8x0.8x3 mm(3))...
  12. pmc Myocardial perfusion magnetic resonance imaging using sliding-window conjugate-gradient HYPR methods in canine with stenotic coronary arteries
    Lan Ge
    Department of Radiology, Northwestern University, Chicago, IL, USA
    J Comput Assist Tomogr 34:684-8. 2010
    ..This method allows for improved spatial coverage, resolution, and SNR...
  13. doi request reprint Off-resonance positive contrast imaging of a passive endomyocardial catheter in swine
    Rohan Dharmakumar
    Department of Radiology, Northwestern University, 737 N Michigan Ave, Suite 1616, Chicago, IL 60611, USA
    Phys Med Biol 53:N249-57. 2008
    ..9 in LV myocardium). The findings show that off-resonance imaging with the FLAPS method may be used for passive device visualization with positive contrast. Further studies are necessary prior to clinical translation...
  14. pmc Parametric dependence of myocardial blood oxygen level dependent, balanced steady-state free-precession imaging at 1.5 T: theory and experiments
    Xiangzhi Zhou
    Department of Radiology, Northwestern University, Chicago, Illinois 60611, USA
    Magn Reson Med 63:484-93. 2010
    ..Additional technical improvements that preserve the image quality may be necessary to further increase the myocardial bSSFP blood oxygen level dependent sensitivity at 1.5 T through even longer pulse repetition times...
  15. ncbi request reprint Dephased FLAPS for improved visualization of susceptibility-shifted passive devices for real-time interventional MRI
    Ioannis Koktzoglou
    Department of Radiology, Northwestern University, Suite 700, 448 E Ontario St, Chicago, IL 60611, USA
    Phys Med Biol 52:N277-86. 2007
    ..In comparison to FLAPS imaging, results demonstrate that dFLAPS imaging of thick, projection-like slices improves the contrast of susceptibility-shifted devices relative to background signal with no increase in acquisition time...
  16. pmc Ischemic extent as a biomarker for characterizing severity of coronary artery stenosis with blood oxygen-sensitive MRI
    Sotirios A Tsaftaris
    Department of Computer Science and Applications, IMT Institutions Markets Technologies Institute for Advanced Studies Lucca, Lucca, Italy
    J Magn Reson Imaging 35:1338-48. 2012
    ..To investigate whether a statistical analysis of myocardial blood-oxygen-level-dependent (mBOLD) signal intensities can lead to the identification and quantification of the ischemic area supplied by the culprit artery...
  17. pmc Comparison of superparamagnetic and ultrasmall superparamagnetic iron oxide cell labeling for tracking green fluorescent protein gene marker with negative and positive contrast magnetic resonance imaging
    Zhuoli Zhang
    Department of Radiology, Northwestern University, Chicago, IL 60611, USA
    Mol Imaging 8:148-55. 2009
    ..MRI of labeled cells with GFP expression holds potential promise for monitoring the temporal and spatial migration of gene markers and cells, thereby enhancing the understanding of cell- and gene-based therapeutic strategies...
  18. doi request reprint Deriving blood-oxygen-level-dependent contrast in MRI with T2*-weighted, T2-prepared and phase-cycled SSFP methods: theory and experiment
    Jain Mangalathu Arumana
    Department of Radiology, Northwestern University, Chicago, Illinois 60611, USA
    Magn Reson Med 59:561-70. 2008
    ..5T and 3.0T; and 2) OC derived with SSFP PC can be increased above GRE and T2-prep methods with an appropriate choice of imaging parameters...
  19. pmc Gadolinium-conjugated TiO2-DNA oligonucleotide nanoconjugates show prolonged intracellular retention period and T1-weighted contrast enhancement in magnetic resonance images
    Tatjana Paunesku
    Department of Radiation Oncology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
    Nanomedicine 4:201-7. 2008
    ..This type of nanoconjugate with increased retention time, Gd accumulation, and intracellular delivery may find its use in Gd neutron-capture cancer therapy...
  20. ncbi request reprint Detecting microcirculatory changes in blood oxygen state with steady-state free precession imaging
    Rohan Dharmakumar
    Department of Medical Biophysics, Sunnybrook and Women s College Health Sciences Centre, University of Toronto, Ontario, Canada
    Magn Reson Med 55:1372-80. 2006
    ....
  21. ncbi request reprint On the parameters affecting the sensitivity of MR measures of pressure with microbubbles
    Rohan Dharmakumar
    Department of Medical Biophysics, Sunnybrook and Women s College Health Sciences Center, University of Toronto, Toronto, Canada
    Magn Reson Med 47:264-73. 2002
    ..15%, and have a volumetric magnetic susceptibility difference of at least 34 ppm...
  22. ncbi request reprint A novel microbubble construct for intracardiac or intravascular MR manometry: a theoretical study
    Rohan Dharmakumar
    Department of Medical Biophysics, Sunnybrook and Women s College Health Sciences Centre, University of Toronto, Toronto, ON M4N 3M5, Canada
    Phys Med Biol 50:4745-62. 2005
    ..5 T must be 2-3 microm in radius and be uniformly coated with single-domain magnetic nanoparticles, such as magnetite, at shell volume fractions below 5%...
  23. ncbi request reprint Oxygen-sensitive contrast in blood for steady-state free precession imaging
    Rohan Dharmakumar
    Department of Medical Biophysics, Sunnybrook and Women s College Health Sciences Centre, University of Toronto, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada
    Magn Reson Med 53:574-83. 2005
    ..It is envisioned that this method could be instrumental in real-time imaging focused on detecting diseases where the oxygen state of blood is impaired...

Research Grants4

  1. 4D SSFP MRI for Detecting Functionally Important Coronary Artery Stenosis at Rest
    Rohan Dharmakumar; Fiscal Year: 2010
    ..Most importantly, the proposed method has the potential to non-invasively detect coronary artery disease, guide initial treatment, and enable clinical management in patient populations with the disease. ..
  2. 4D SSFP MRI for Detecting Functionally Important Coronary Artery Stenosis at Rest
    Rohan Dharmakumar; Fiscal Year: 2009
    ..Most importantly, the proposed method has the potential to non-invasively detect coronary artery disease, guide initial treatment, and enable clinical management in patient populations with the disease. ..