Farquhar, Thomas Henry, MD, PhD

Thomas Henry Farquhar, MD, PhD

Diagnostic Radiology

Location Information

  • Jefferson Radiology
    85 Seymour Street Suite 200
    Hartford, CT 06106


About Thomas Henry Farquhar, MD, PhD

  • Gender
  • Language
  • Specialties
    Accepting New Patients

    Diagnostic Radiology, Radiology

  • Areas of Expertise
    Body Imaging, Body MRI, Emergency Radiology, Gastrointestinal Radiology, Genitourinary Radiology, Lung Cancer Screening, Oncologic Imaging, PET (Positron Emmision Tomography), Radiation Safety and Radiation Dose Reduction, Thoracic Radiology

Hospitals and Organizations


  • Graduate SchoolUniversity of California (LA)

    InternshipUniversity of California Medical Center

    Medical SchoolUniversity of California (LA)

    ResidencyUniversity of California Medical CenterUniversity of California Medical Center

    UndergraduateStanford University

  • Professional Organizations

    American Roentgen Ray Society
    Society of Nuclear Medicine
    American College of Radiology
    Radiological Society of North America


A new, state-of-the-art PET CT scanner is creating a lot of buzz at Hartford HealthCare...particularly the lower radiation dose being one of the models many benefits… Joining us to talk more about this latest advancement in PET CT scanners is Dr. Thomas Farquhar, a Radiologist at Hartford Hospital…

Good evening!

Q. Tell us about this new PET CT scanner. What are the benefits?

A. This new PET CT scanner represents an investment by Hartford Healthcare in the most leading-edge technology available. A PET CT scanner is actually two scanners combined into one piece of equipment. There is a CT scanner, or CAT scanner, which many patients would recognize. The CT scanner is used to get anatomic images of the body and to calculate corrections to the PET scan even more accurate. The other scanner is even more exciting – a fully digital PET scanner. No facility will have a more modern PET scanner and there have only been 20, maybe 25 of these installed across the United States. The advantages are more accurate images, with better signal, lower radiation dose, in a shorter period of time, seeing more patients each day. We have been able to shorten the exam time on the scanner from 60 minutes to 45 minutes, which means we can schedule 11 patients on a typical day, up for 7.

Q. Describe the lower dose technology?

Patients will benefit from a lower dose from both the CT and PET exams on this new scanner. Modern CT scanners vary the number of x-rays used depending on the thickness of the body to use only what is necessary – using fewer x-rays on thinner parts of the body or smaller patients. This way uses ½ to 1/3 of the radiation needed previously. Patients also receive radiation from the tracer injected for the PET scan -- most commonly a radioactive analog of sugar called FDG. The PET scanner now operates in a 3D mode rather than 2D mode, collecting data on the location of the FDG in every direction, making the scanner 7 or 8 times more sensitive. Because of this, we can inject 1/3 less radio-tracer, and still get superior images.

Q. How accurate/precise is this new scanner compared to others?

A. The metric we use is called the scanner’s resolution, the ability to separate two small nearby objects. An older PET scanner might have a resolution of around 5/16 of inch, or about 8mm. That sounds quite small, but in order to identify cancer earlier, this new PET CT has a resolution of 3/16, only 4.5 mm. The scanner is able to do this using amazing electronics that are actually able to calculate the distance between two photons of radiation moving at the speed of light and then use a powerful computer to do the math to turn the data into an image.

Q. What should patients know, what questions should they be asking?

A. Patients should know that with a combination of this state-of-the-art technology and the expertise of the physicians who interpret the images, the Imaging Center at Hartford Hospital is able to benefit patients in even more ways than before. For example, we have a new radio-tracer called fluciclovine is helpful in certain patients with suspected prostate cancer recurrence. And PET isn’t just a technique used in cancer – it can be used to localize epilepsy or even make an earlier diagnosis of Alzheimer’s disease in some patients.

Patients should ask their doctor where to go to have their study with a latest technology, interpreted by physicians with expertise in reading PET CT scans.

Thank you, Dr. Farquhar, for joining us and sharing how this new technology will help patients.

If you would like to learn more about this new CT scanner, call 1-855-HHC-HERE.


Aetna, Anthem, BCBS Medicare, CarePartners of Connecticut, Cigna Healthcare, Colonial Cooperative Care, Community Health Network of Connecticut, Inc., Connecticare, Connecticare Commercial, Connecticare Medicare, Corvel, Coventry, Essence Healthcare, Evercare, First Health Group Corp., Focus, Harvard Pilgrim, Health Connecticut, Health Direct, Health New England, Healthy Connecticut, HMC/ Northeast Healthcare, Medspan Commercial, Medspan Medicare, Multiplan, Northeast Health Direct, One Health Plan/ Great-West Healthcare, Oxford Health Plans, Prime Health Services, Private Health Care Systems, Inc., Senior Whole Health, United Healthcare, WellCare of Connecticut, Inc.
This information is subject to change at any time. Please check with your insurance provider before scheduling your appointment or receiving services to confirm they are a participating member of the Hartford HealthCare network.
Back to Top