Wang, Yi

Professor

research

research and scholarship focus

Our prime interests are the science and engineering of magnetic resonance (MR) imaging, and application in clinical practice. Currently we are developing techniques for imaging blood flow in large vessels (angiography) and in microvasculature (perfusion). These techniques are targeted for applications in cardiovascular diseases and neuro-functional mapping.
  • Cardiac MRI Cardiovascular diseases is the No. 1 killer in the United States. Non-invasive diagnosis of cardiovascular diseases using MR would significantly advance patient care. For example, screening lesions in coronary arteries in their early stage prior to heart attack would provide a tremendous saving of lives. The challenge to imaging coronary arteries that supply blood to cardiac muscle is motion - cardiac contraction and respiration. This motion is difficult to predict by a model. We are developing techniques based on "imaging in the motion frame." The motion of the heart is sampled with navigator signals, which are processed in real-time and fed back to modify data acquisition accordingly, to eliminate motion artifacts. Substantial computer engineering and image processing are being integrated in this intelligent model-free navigator method.
  • Functional MRI Human organ functions depend on and also affect blood supply. Accordingly, tissue perfusion provides assessment of organ function. Neuro-activation of the brain affects blood oxygenation level and perfusion rate. Neuro-function areas in the cortex can be mapped out by dynamic perfusion imaging synchronized to activation. MR brain mapping is one of the most exciting development in neuroscience, but the technology is still at its early stage. We are examining data acquisition strategies to improve signal-to-noise ratio and biophysics models to better understand the relation between activation and MR signal response.
  • MR Angiography Our research work applies directly to clinical practice. We have developed non-invasive fluoroscopic MRA - MR digital subtraction angiography (MRDSA), and applied MRDSA to image vascular diseases in the lower extremity. To overcome the problem of the large longitudinal extend in the lower extremity (~ 100 cm, from aortic bifurcation to the feet), we developed a bolus chase MRDSA technique. Angiographic data acquisition follows the peak of the contrast passage (contrast bolus) from the proximal (aortic bifurcation) to distal location (feet), shortening scan time and minimizing contrast dose. Preliminary data confirmed that bolus chase MRDSA is a fast, accurate, and dose-minimized method, and bolus chase MRDSA is now a routine clinical tool at Cornell Medical Center, an non-invasive and economic alternative to x-ray Angiography.

research areas

affiliations

faculty appointment in

member of graduate field

background

educational background

  • Ph.D. 1994, University of Wisconsin, Medical Physics
  • B.S. 1986, Fudan University (Shanghai), Nuclear Physics

professional background

Dr. Wang was a member of the Cornell faculty during 1997-2001, Director of Cardiovascular MRI at University of Pittsburgh Medical Center during
2001-2004, and has rejoined Cornell as Faculty Distinguished Professor in Radiology in 2004.

publications

selected publications (listing in progress)

  • Raj A, Zhang H, Prince MR, Wang Y, Zabih R, “An Automatic Algorithm for Correcting Motion Artifacts In Time-Resolved 2D MR Angiography Using Convex Projections.” Magnetic Resonance in Medicine 55(3):649-58.
  • Cheng L, Gao Y, Guaricci AI, Mulukutla S, Sun W, Sheng F, Foo TK, Prince MR, Wang Y, “Breath-hold 3D steady state free precession coronary MRA: compared to conventional x-ray coronary angiography.” Journal of Magnetic Resonance Imaging 23(5):6669-673.
  • Nguyen TD, Spincemaille P, Prince MR, Wang Y, “Cardiac Fat Navigator Gated Steady State Free Precession 3D Magnetic Resonance Angiography of Coronary Arteries.” Magnetic resonance in Medicine 56:210-5.
  • Qian Y, Zhang Z, Wang Y, Boada F, “Decomposed direct matrix inversion for fast non-Cartesian SENSE reconstructions.” Magnetic resonance in Medicine 56:356-63.
  • Kressler B, Spincemaille P, Nguyen TD, Prince MR, Wang Y, “Reduction of reconstruction time for time-resolved spiral 3D contrast-enhanced magnetic resonance angiography using parallel computing.” Magnetic Resonance in Medicine 56:704-8.
  • Raj A, Kressler B, Singh G, Zabih R, Wang Y, “Statistical aspects of parallel imaging reconstruction.” Proceedings of the 28th IEEE EMBS annual international conference 377-380.
  • Qian Y, Zhang Z, Stenger VA, Wang Y, “Self calibrated spiral SENSE.” Magnetic Resonance in Medicine 52:688-692.
  • Spincemaille P, Nguyen TD, Wang Y, “View ordering for magnetization prepared steady state free precession acquisition: application in contrast enhanced magnetic resonance angiography.” Magnetic Resonance in Medicine 52:461-466.
  • Kolmogorov V, Nguyen TD, Nuval A, Spincemaille P, Prince MR, Zabih R, Wang Y, “A multi-processor scheduling implementation of simultaneous multiple volume (SMV) navigator method.” Magnetic Resonance in Medicine 52:362-367.
  • Zhu H, Buck DG, Zhang Z, Zhang H, Wang P, Stenger VA, Prince MR, Wang Y, “High temporal and spatial resolution 4D MRA using spiral data sampling and sliding window reconstruction.” Magnetic Resonance in Medicine 52:14-18.
  • Zhang HL, Khilnani NM, Prince MR, Winchester PA, Golia P, Veit P, Watts R, Wang Y, “Diagnostic accuracy of time-resolved 2D projection MR angiography for symptomatic infrapopliteal arterial occlusive disease.” AJR 183(4):1041-7.
  • Trost DW, Zhang HL, Prince MR, Winchester PA, Wang Y, Watts R, Sos TA, “Three-dimensional MR angiography in imaging platinum alloy stents.” Journal of Magnetic Resonance Imaging 20(6):975-80.
  • Brown R, Mareyam A, Reid E, Wang Y, “Improved RF Coil Geometry for Lower Extremity Imaging.” Magnetic Resonance in Medicine 51:635-639.
  • Nguyen TD, Nuval A, Mulukutla S, Wang Y, “Direct monitoring of coronary artery motion with cardiac fat navigator echoes.” Magnetic Resonance in Medicine 50:235-41.
  • Wang Y, Truong TN, Yen C, Bilecen D, Watts R, Trost DW, Prince MR, “Quantitative evaluation of susceptibility and shielding effects of nitinol, platinum, cobalt and stainless steel stents.” Magnetic Resonance in Medicine 49:972-976.
  • Kolmogorov VN, Watts R, Prince MR, Zabih R, Wang Y, “An efficient real-time navigator algorithm: simultaneous multiple volume (SMV) acquisition.” Magnetic Resonance Imaging 21:969-975.
  • Wang Y, “Real-time navigator approach to motion problems in coronary MRA.” IEEE Computer Society Proceedings of IEEE Computer Society conference on Medical Imaging and Augmented Reality 44-52.
  • Wang Y, Lee HM, Khilnani NM, Trost DW, Jagust M, Bush HL, Sos TA, Sostman HD, “Bolus chase MR digital subtraction angiography of the entire lower extremity in one minute.” Radiology 207, 263-269.
  • Wang Y, Johnston DL, Breen JF, Huston III J, Jack CR, Julsrud PR, Riederer SJ, Ehman RL, “Dynamic MR digital subtraction angiography using contrast enhancement, fast data acquisition, and complex subtraction.” Magnetic Resonance in Medicine 36, 551-556.
  • Wang Y, Rossman PJ, Grimm RC, Riederer SJ, Ehman RL, “Navigator-echo-base real-time respiratory gating and triggering for reduction of respiration effects in three-dimensional coronary MR imaging.” Radiology 198:55-60.
  • Wang Y, Riederer SJ, Ehman RL, “Respiratory motion of the heart: kinematics and the implications for the spatial resolution in coronary imaging.” Magnetic Resonance in Medicine 33:713-9.