Ryan D. Niederkohr, MD

Clinical Assistant Professor, Radiology

Ryan Niederkohr
700 Lawrence Expy, 1st Floor Dept 120


I earned my undergraduate degree from the University of Notre Dame and my Medical Degree from The Ohio State University (2003). I then completed my postgraduate nuclear medicine training at Stanford, where I had the opportunity to learn from world-renowned leaders and researchers in nuclear medicine and radiology. I joined Kaiser Permanente Santa Clara in 2008.

My medical interests lie in the domain of diagnostic imaging: specifically, the clinical applications of molecular imaging. My primary interest is PET/CT imaging, a powerful imaging tool which provides functional and anatomic data in a single exam. PET/CT has revolutionized the practice of oncology and will continue to do so as new molecular imaging agents become available. I love that my job involves antimatter and allows me to work with cutting-edge technology. I also enjoy working closely with my clinical colleagues in medical oncology, surgery, and radiation oncology to ensure that PET studies are performed and interpreted in a way that optimizes the care of our members with cancer.

As a nuclear medicine physician, I am also experienced in other aspects of nuclear imaging including SPECT/CT imaging, cardiovascular imaging (including cardiac stress testing and myocardial perfusion imaging) and therapeutic nuclear medicine including radioactive iodine treatment of thyroid disease (hyperthyroidism and thyroid cancer) and radioimmunotherapy for lymphoma. I am also trained and certified to perform and interpret cardiovascular CT/CTA.

I currently serve as Chief of the Department of Nuclear Medicine at Santa Clara.

I am proud to hold leadership roles in the Society of Nuclear Medicine and Molecular Imaging (SNMMI). I have been a Board Member of the SNMMI PET Center of Excellence since 2009 and have served as chairman of the SNMMI PET Quality and Reporting Taskforce since 2012. I have presented invited lectures on nuclear medicine and PET/CT at national and international conferences, have published multiple peer-reviewed journal articles, and serve as a reviewer for several medical journals.

Other Positions

  • Kaiser Permanente Santa Clara Medical Center


  • Ohio State University, MD
  • University of Notre Dame, BS


  • Published on 3/15/2019

    Zukotynski KA, Niederkohr RD, Greenspan BS, Prior JO, Schöder H, Seltzer MA, Rohren EM, Yoo DC. An International Survey of PET/CT Clinical Reporting. J Nucl Med. 2019 Apr; 60(4):478-479. PMID: 30877176.

    Read at: PubMed
  • Published on 12/1/2018

    Sanli Y, Zukotynski K, Mittra E, Chen DL, Nadel H, Niederkohr RD, Subramaniam RM. Update 2018: 18F-FDG PET/CT and PET/MRI in Head and Neck Cancer. Clin Nucl Med. 2018 Dec; 43(12):e439-e452. PMID: 30394934.

    Read at: PubMed
  • Published on 6/1/2017

    Wright CL, Niederkohr RD, Knopp MU, Knopp MV. Online Social Media Practices in Nuclear Medicine and Molecular Imaging: A Concept to Incentivize Creation of Digital and Web-Based Content. J Nucl Med. 2017 06; 58(6):12N-14N. PMID: 28572291.

    Read at: PubMed
  • Published on 11/22/2016

    Moghbel MC, Mittra E, Gallamini A, Niederkohr R, Chen DL, Zukotynski K, Nadel H, Kostakoglu L. Response Assessment Criteria and Their Applications in Lymphoma: Part 2. J Nucl Med. 2017 Jan; 58(1):13-22. PMID: 27879369.

    Read at: PubMed
  • Published on 9/29/2016

    Zukotynski K, Jadvar H, Hope T, Subramaniam RM, Van Loon K, Varma M, Niederkohr RD. SNMMI Comment on the 2016 Society of Surgical Oncology "Choosing Wisely" Recommendation on the Use of PET/CT in Colorectal Cancer. J Nucl Med. 2017 01; 58(1):11-12. PMID: 27688471.

    Read at: PubMed
  • Published on 7/29/2016

    Meltzer C, Budayr A, Chavez A, Dlott R, Greif W, Gurushanthaiah D, Klonecke A, Lando M, Leary J, Nayak S, Niederkohr R, Park J, Savitz A, Schwartz H. Evidence-Based Workflows for Thyroid and Parathyroid Surgery. Perm J. 2016; 20(3):57-73. PMID: 27479948.

    Read at: PubMed
  • Published on 4/28/2016

    Moghbel MC, Kostakoglu L, Zukotynski K, Chen DL, Nadel H, Niederkohr R, Mittra E. Response Assessment Criteria and Their Applications in Lymphoma: Part 1. J Nucl Med. 2016 Jun; 57(6):928-35. PMID: 27127227.

    Read at: PubMed
  • Published on 11/14/2013

    Olcott P, Pratx G, Johnson D, Mittra E, Niederkohr R, Levin CS. Clinical evaluation of a novel intraoperative handheld gamma camera for sentinel lymph node biopsy. Phys Med. 2014 May; 30(3):340-5. PMID: 24239343.

    Read at: PubMed
  • Published on 8/1/2013

    Niederkohr RD, Chiu E, Katzel JA. 99mTc-oxidronate uptake within urothelial carcinoma confirmed with SPECT/CT imaging. Clin Nucl Med. 2013 Aug; 38(8):655-7. PMID: 23751825.

    Read at: PubMed
  • Published on 4/10/2013

    Niederkohr RD, Greenspan BS, Prior JO, Schöder H, Seltzer MA, Zukotynski KA, Rohren EM. Reporting guidance for oncologic 18F-FDG PET/CT imaging. J Nucl Med. 2013 May; 54(5):756-61. PMID: 23575994.

    Read at: PubMed

View 19 more publications: View full profile at BUMC

View all profiles