Non-Invasive Cardiovascular Imaging Section
The Non-Invasive Cardiovascular Imaging Section is composed of four service-units providing support for patient care, medical education and research, both clinical and experimental. The backbone of the service remains the Echocardiography Laboratory.
The remaining three units (Cardiac MRI service, Vascular Imaging Laboratory, and Cardiovascular CT) are at different stages of development and provide support to research and teaching activities at the present time.
The Echocardiographic Laboratory
he central nervous system of the Echocardiographic Laboratory is located at the 5th floor of the Alfred Blalock Building, The Johns Hopkins Hospital. It occupies the entire east wing of the building comprising four large rooms dedicated to the acquisition of all types of cardiac ultrasound examinations, including transthoracic and transesophageal echocardiograms, at rest and during pharmacologic and exercise induced stress.
Facilities at the Blalock building also include a viewing area for test interpretation and space for the offices of medical director, sonographers and nurses staffing the laboratory. In addition, the laboratory occupies three examining rooms at the Johns Hopkins Outpatient Center with adjacent viewing area and office for sonographers assigned to the outpatient center.
10,000 Echocardiographic Studies Yearly
The laboratory is equipped with 12 top of line echocardiographic systems, three of which are solely dedicated to research. It is staffed with eight full time and two part time sonographers, and two full time nurses, dedicated to clinical and investigative echocardiography. Staff performs approximately 10,000 echocardiographic studies per year, and it is, at the present time, in the process of transitioning to digital technology for acquisition, archival and retrieval of echocardiographic images.
Satellite echocardiographic laboratories located at all Johns Hopkins community sites, including White Marsh, Green Spring Station, Odenton, Columbia, and at the Johns Hopkins Bayview Medical Center, function in close connection with the central echocardiographic laboratory. The studies are performed by sonographers trained at the main hospital but are interpreted locally by faculty physicians staffing the respective clinics. Digital connections link the satellite locations so the databases of such laboratories will be linked to the main echocardiographic database at Hopkins.
Non-Invasive Faculty also cover the volume of transesophageal echocardiograms in the operating room (approximately 800 studies per year) which are daily performed by a group of anesthesiologists trained in the performance and interpretation of these studies by the Non-Invasive Imaging Section. The commitment to medical education is illustrated by the fact that at all times; at least three full time cardiology clinical fellows are assigned to the echocardiography laboratory. In addition, a school for training sonographers has been pioneered in the laboratory with 4-6 students trained annually. One regular conference to review the important cases of the week is held on Thursdays and an additional section on the interpretation of intra-operative TEEs is held every Tuesday.
The Cardiac MRI Service
The Cardiac MRI Service is jointly managed by Drs. David A. Bluemke in the Department of Radiology and Joao A. C. Lima in the Division of Cardiology, Department of Medicine. The service supports basically two activities, namely clinical studies and clinical research.
Activities are generally based in the cardiovascular magnet installed in the 5th floor of the Blalock building. Clinical research activities at this point involve the:
- investigation of global and regional left ventricular function by MRI tissue tagging
- measurements of infarct size and microvascular obstruction by contrast enhanced MRI,
- development of myocardial perfusion techniques and vascular MRI applications
The letter component of the clinical research endeavor includes efforts to develop MR coronary angiography and endothelial function test by brachial artery imagery.
Clinical research also entails a large effort of the development and implementation of transesophageal MRI techniques to quantify atherosclerosis and monitor the effect of lipid lowering therapy. The clinical Cardiovascular MRI Service provides support to the clinical activities of the Johns Hopkins Hospital and also to outpatient referrals for specific cardiovascular MRI studies. Finally, the Cardiovascular MRI Service supports the Multi-Ethnic Study on Atherosclerosis and functions as the Reading Center for all MRI studies obtained in that large Multi-center NIH funded effort.
Cardiovascular CT Service
The cardiac CT program, directed by Dr. Joao Lima of Cardiology and Radiology, brings together cardiovascular expertise from throughout the Johns Hopkins Institutions. The team includes: Richard George, Armin Zadeh, Jeffrey Brinker, Julie Miller, David Bush and Edward Shapiro.
The program supports clinical service, along with a diverse array of research and educational activities. The East Baltimore service is based on Blalock 5 and is mostly dedicated to the performance of cardiac CT examinations. Educational activities take place at Johns Hopkins Bayview Medical Center where the most comprehensive cardiac CT Course is held. With the installation of a 256-row multidetector computed tomography (MDCT) system in the early fall of 2007, the service will lead the way with the most advanced technology for the non-invasive diagnosis of cardiac disease.
Clinical research activities include the development of non-invasive coronary angiography and coronary plaque imaging, as well as the development of perfusion and viability imaging using 64 and 256-row MDCT. Johns Hopkins Cardiology currently leads the first multi-center trial aimed at validating the accuracy of 64-row MDCT angiography. Further, studies in coronary calcium screening and the non-invasive evaluation of coronary bypass grafts round out the active clinical research program.