Cardiovascular Imaging

The Cardiovascular Imaging Section of CVRI, directed by Dr. Tim Christian, comprises three, integrated components focusing on Computer Assisted Tomography (CT) applied to coronary angiography, Nuclear Cardiology including Positron Emission Tomography (PET), Magnetic Resonance Imaging (MRI), and Echocardiography. These components are under the direction of Drs. Matt Watkins, Ken Brown, Tim Christian, and Marc Tischler, respectively. The Section utilizes digital cardiac imaging technology coupled with recent advances in computer capacity and speed in research involving a broad spectrum of activities utilizing all four imaging modalities.  The Departments of Radiology and the Cardiology Unit in the Department of Medicine work closely together in many of the activities in progress. 

Our initial work with computed tomography employed a 40-slice CT scanner. Subsequently, we have been utilizing a 64-slice CT scanner in a program under the combined leadership of Drs. Matt Watkins and Curtis Green, both of whom have extensive experience in the field of computed CT and conventional angiography.  Dr. Ken Brown spearheads the nuclear cardiology program which is internationally recognized.  Its activities entail use of three state-of the-art SPECT cameras in inpatient and outpatient facilities and a PET scanner for assessment of myocardial viability and Rubidium myocardial perfusion studies. Work in this area focuses on assessment of prognosis and cardiovascular disease associated with diabetes mellitus.  Photo: Myocardial perfusion detected with MnCl2 and MRI.

With respect to our magnetic resonance imaging program, the University of Vermont is one of only a small number of institutions in the country with a cardiac-capable 3 Tesla magnet.  A focus of our magnetic resonance imaging research is on enhancement of signal intensity and resolution at this field strength for applications in translational research. Our cardiac magnetic resonance imaging activities are led Dr. Tim Christian, who has extensive experience in studies in patients and experimental animals addressing myocardial perfusion and physiology.

Our echocardiogrphic laboratory is directed by Dr. Marc Tischler.  Its focus is on valvular heart disease and restorative forces in congestive heart failure.  Dr. Tischler interdigitates the echocardiographic laboratory research with investigations in magnetic resonance imaging. He has extensive experience with both modalities 

All of the faculty in the imaging section of CVRI have expertise in multiple imaging modalities. They work closely with clinical and basic scientists in the elucidation of pathophysiology of cardiovascular disease, improved diagnosis, and delineation of determinants of prognosis and responses to therapy.

Fujisawa Pharmaceutical Company
“Assessment of responsiveness to vasodilator stress in patients exposed to recent caffeine ingestion:  Relationship of adenosine challenge sensitivity to serum caffeine levels and time from ingestion”
2003 (Dr. Ken Brown, PI)

Bristol Myers Squibb Pharmaceutical Company
“A phase IV open-label, randomized, multi-center trial to evaluate the ability of technetium Tc99m sestamibi stress myocardial perfusion imaging to detect asymptomatic restenosis in diabetic patients who have undergone percutaneous coronary intervention”
2003 (Dr. Ken Brown, PI)

American Heart Association
High Field Magnetic Resonance Quantitative Myocardial Perfusion Imaging
0455650Z (Dr. Tim Christian, PI)

Representative Publications

Brown KA, Heller GV, Landin RJ, Shaw LJ, Beller GA, Pasquale MJ, Haber SB.  Early Dipyridamole Tc99m-sestamibi SPECT imaging 2-4 days after acute myocardial infarction predicts in-hospital and post-discharge cardiac events:  comparison with submaximal exercise imaging.  Circulation 1999; 100:2060-2066.

Gibbons RJ, Miller TD, Christian TF.  Infarct size measured by single photon emission computed tomography with Tc-99m sestamibi: a measure of the efficacy of therapy in acute myocardial infarction.  Circulation 2000; 101:101-108.

Grines C, Watkins MW, Helmer G, Penny W, Brinker J, Marmur J, West A, Rade JJ, Marrott P, Hammond HK, Engler RL.  Angiogenic gene therapy (AGENT) trial in patients with stable angina pectoris.  Circulation 2002; 105:1291-1297.

Grines C, Watkins MW, Mahmarian JJ, Iskandrian AE, Rade JJ, Marrott P, Pratt C, Kleiman N.  A randomized double blind placebo-controlled trial of Ad5FGF-4 gene therapy and its effect on myocardial perfusion in patients with stable angina (AGENT 2).  J Am Coll Cardiol 2003; 42:1339-1347.

Watkins MW, Rubanyi GM.  Gene therapy for coronary artery disease: Preclinical and initial clinical results with intracoronary Ad5-FGF-4 in human gene therapy:  Current opportunities and future trends edited by Rubanyi GM and Yla-Herttuala S.  Springer-Verlag, Heidelberg, Germany, 2003, pp. 173-188.

Brown KA.  Nuclear cardiology techniques in acute coronary syndromes.  In:  Theroux P.  Acute Coronary Syndromes: A companion to Braunwald’s Hearta Disease.  Saunders Publishing, Philadelphia, 2003.

Tischler M, Niggel JL.  Left ventricular systolic torsion and exercise in normal hearts.  J Am Soc Echo 2003; 16:670-674.

Christian TF, Rettmann D, Aletetras AH, Liao S, Taylor JL, Balaban RS, Arai AE.  Absolute myocardial perfusion in canines measured by using dual-bolus first-pass MR imaging.  Radiology 2004; 232:677-684.

Araoz PA,  Glockner JF, McGee KP, Potter DD, Valeti VU,  Stanley DW, Christian TF. 3 Tesla MR imaging provides improved contrast in first-pass myocardial perfusion imaging over a range of gadolinium doses.  J Cardiac Magn Reson Imaging 2005; 7:559-564.

Brown KA.  Risk stratification in acute coronary syndromes.  In: Zaret BL, Beller GA.  Clinical Nuclear Cardiology:  State-of-the-Art and Future Directions 3rd Edition, in press.