Graduate Studies Faculty

Andrzej Krol, PhD

Andrzej Krol, PhD
Appointed 01/05/94
113B Upstate University Hospital - Downtown Campus
750 East Adams Street
Syracuse, NY 13210

315 464-8668

Current Appointments

Hospital Campus

  • Downtown

Clinical Section Affiliations

  • Radiology: Clinical Radiological Physics Section, Diagnostic Division, Image Science and Informatics, Nuclear Medicine

Research Programs and Affiliations

  • Biomedical Sciences Program
  • Center for Psychiatric Neuroimaging
  • Radiology

Education & Fellowships

  • Fellowship: SUNY Upstate Medical University, 1994, Medical Physics
  • Postdoctoral Fellow: SUNY Stony Brook, 1989
  • PhD: Warsaw University, Poland, 1980
  • MS: Warsaw University, Poland, 1974

Clinical Interests

  • Advanced quantitative imaging in Single Photon Emission Tomography combined with CT (SPECT/CT)
  • Advanced quantitative imaging in Positron Emission Tomography combined with CT (PET/CT)
  •  Low-dose molecular imaging (SPECT/CT and PET/CT)
  • Transarterial radioembolization via intrahepatic administration of Y-90 microspheres for the treatment of hepatocellular carcinoma (HCC) and metastatic liver deposits from other malignancies.

Education Interests

  • Physics of Nuclear Medicine – preparation of Radiology residents for board exams
  • Physics of Nuclear Cardiology – preparation of Cardiology fellows for board exams

 

Research Interests

Development of:

  • Extremely low-dose and high-resolution tomographic reconstruction methods in PET and SPECT
  • Advanced ultrafast PET detector
  • Advanced very high-sensitivity and high-spatial resolution brain PET scanner
  • Ultrafast laser-based betatron microfocal x-ray source for very high-resolution biomedical imaging
  • PET bioprobe for detection and treatment of hepatocellular carcinoma and other cancers
  • Advanced breast cancer detection methods in mammography

Clinical Trials

  • Lumpectomy Surgical Margins Determination by Means of Micro-CT
    Read more

Specialties & Certification

  • Medical Nuclear Physics

Treats

  • Adults and Children

Treatments/Services

  • Heart Nuclear Imaging
  • Heart Nuclear Stress Testing
  • Nuclear Imaging
  • Positron Emission Tomography (PET)
  • Radionuclide Scanning

Associations/Memberships

  • American Roentgen Ray Society (ARRS)
  • New York Academy of Sciences
  • American College of Radiology (ACR)
  • Society of Nuclear Medicine (SNM)
  • American Association of Physicists in Medicine

Current Hospital Privileges

  • Upstate University Hospital

Languages Spoken (Other Than English)

  • Polish

Web Resources

Publications

Link to PubMed External Icon (Opens new window. Close the PubMed window to return to this page.)

Research

Preconditioned Alternating Projection Algorithms for Maximum a Posteriori ECT Reconstruction

We propose a preconditioned alternating projection algorithm (PAPA) for solving the maximum a posteriori (MAP) emission computed tomography (ECT) reconstruction problem. Specifically, we formulate the reconstruction problem as a constrained convex optimization problem with the total variation (TV) regularization. We then characterize the solution of the constrained convex optimization problem and show that it satisfies a system of fixed-point equations defined in terms of two proximity operators raised from the convex functions that define the TV-norm and the constrain involved in the problem. The characterization (of the solution) via the proximity operators that define two projection operators naturally leads to an alternating projection algorithm for finding the solution. For efficient numerical computation, we introduce to the alternating projection algorithm a preconditioning matrix (the EM-preconditioner) for the dense system matrix involved in the optimization problem. We prove theoretically convergence of the preconditioned alternating projection algorithm. In numerical experiments, performance of our algorithms, with an appropriately selected preconditioning matrix, is compared with performance of the conventional MAP expectation-maximization (MAP-EM) algorithm with TV regularizer (EM-TV) and that of the recently developed nested EM-TV algorithm for ECT reconstruction. Based on the numerical experiments performed in this work, we observe that the alternating projection algorithm with the EM-preconditioner outperforms significantly the EM-TV in all aspects including the convergence speed, the noise in the reconstructed images and the image quality. It also outperforms the nested EM-TV in the convergence speed while providing comparable image quality.

Clinical Profile Shortcut: http://www.upstate.edu/findadoc/krola
Faculty Profile Shortcut: http://www.upstate.edu/faculty/krola
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