European Society of Radiology: Could you please give a detailed overview of when and for which diseases you use cardiac imaging?
Andrei Šamarin: In a radiology department, non-invasive cardiac imaging is used for the diagnosis and follow-up of the following diseases (below the most common indications are listed):
- Ischaemic heart disease: exclusion of significant coronary artery disease in patients with low to intermediate pre-test probability; assessment of myocardial perfusion at stress and rest in patients with suspected or previous angiographically diagnosed coronary artery stenosis; assessment of patency of bypass grafts, myocardial viability in the setting of chronic myocardial infarction or chronic occlusion of one of the coronary arteries
- Myocarditis: diagnosis in acute stage, follow-up in selected patients after treatment
- Pericarditis: diagnosis in acute stage, follow-up in selected patients after treatment
- Valvular heart disease: determination of the degree of aortic valve regurgitation and stenosis, pulmonary valve regurgitation and stenosis
- New-onset heart failure: determination of the possible aetiology
- Infiltrative cardiomyopathies: diagnosis and follow-up
- Idiopathic cardiomyopathies: diagnosis and follow-up
- MINOCA: aetiology, localisation and extent of myocardial damage in the setting of acute coronary syndrome with non-obstructive coronary arteries on invasive angiography
- Cardiac masses: characterisation and extent
- Atrial fibrillation: prior ablation
- Cardiac infections including prosthetic material infection
- Transcatheter aortic valve implantation (TAVI) planning
ESR: Which modalities are usually used for what?
- CT – exclusion of significant coronary artery disease in patients with low to intermediate pre-test probability, assessment of patency of bypass grafts, left atrial and pulmonary vein morphology, exclusion of left atrial thrombus, TAVI planning
- MR – assessment of myocardial viability and perfusion at pharmacological stress and rest, myocarditis and pericarditis, diagnosis of cardiac involvement by sarcoidosis or amyloidosis, iron overload, cardiomyopathies, cardiac masses, valvular heart disease
- SPECT – myocardial perfusion at stress and rest
- FDG-PET – sarcoidosis, suspected cardiac infection, vasculitis, myocardial viability
ESR: What is the role of the radiologist within the ‘heart team’? How would you describe the cooperation between radiologists, cardiologists, and other physicians?
AŠ: Cardiac CT and MR studies are performed by a radiological technologist under the supervision of a radiologist and reported by the radiologist. The choice of diagnostic strategy including appropriate imaging modality is discussed with the cardiologist on an individual patient level. There are regular heart team meetings with an active role of the radiologist where preselected cases are discussed.
ESR: Radiographers/radiological technologists are also part of the team. When and how do you interact with them?
AŠ: Radiologists responsible for cardiac imaging actively communicate with radiological technologists by assisting in proper imaging protocol selection and modifying the protocol to meet the clinical question, by supervising the myocardial stress perfusion studies with adenosine and by leading and supervising the patient preparation for coronary CT angiography.
ESR: Please describe your regular working environment (hospital, private practice). Does cardiac imaging take up all, most, or only part of your regular work schedule? How many radiologists are dedicated to cardiac imaging in your team?
AŠ: I work at a tertiary level teaching hospital. Cardiac imaging takes up to 50% of my regular work schedule. There are four radiologists with special training and expertise in cardiac imaging in our department.
ESR: Do you have direct contact with patients and if yes, what is the nature of that contact?
AŠ: Radiologists have direct contact with a patient to explain the need for β-blocker and nitro-glycerine administration and assess the possible contraindications prior to coronary CT angiography if needed. Direct contact with a patient occurs during adenosine infusion while performing MR or SPECT myocardial stress perfusion if needed due to side effects of adenosine.
ESR: If you had the means: what would you change in education, training and daily practice in cardiac imaging?
AŠ: Special training for radiological technologists in cardiac imaging. MR scanner dedicated to cardiac imaging with technologists having a subspecialisation in cardiac scanning.
ESR: What are the most recent advances in cardiac imaging and what significance do they have for improving healthcare?
AŠ: In MR imaging, validation and implementation of quantitative T1 and T2 myocardial mapping to the routine clinical routine. It allows improved diagnostic accuracy in diagnosis and follow-up of diseases with diffuse myocardial infiltration and fibrosis as well as higher diagnostic confidence in the assessment of focal myocardial damage.
In CT imaging, the introduction of wide detector CT scanners with fast gantry rotation and advanced iterative reconstruction allows improved image quality of coronary CT angiography with reduced radiation dose leading to confident stratification of patients with atypical chest pain.
ESR: In what ways has the specialty changed since you started? And where do you see the most important developments in the next ten years?
AŠ: In our institution, we started with coronary CT angiography in 2005 and with cardiac MR in 2006, during these 13 years we saw the full development of cardiac imaging into a dedicated subspecialty with over 500 cardiac CT and over 500 cardiac MR exams performed annually.
During the next years, I expect to see development in faster, self-gated MR imaging allowing robust quantification of the acquired imaging data. In CT imaging, non-invasive fractional flow reserve (FFR) calculation and myocardial perfusion imaging using spectral imaging will likely enter clinical routine.
ESR: Is artificial intelligence already having an impact on cardiac imaging and how do you see that developing in the future?
AŠ: We don’t use artificial intelligence yet but its arrival is inevitable. AI can increase the efficiency of our work and potentially lead to better patient care.
Dr. Andrei Šamarin is a radiologist and Head of the Cardiothoracic Imaging Section of the Radiology Department at North Estonia Medical Center in Tallinn, Estonia. He trained in Tartu University in general radiology and completed a cardiac imaging fellowship at the University of Florida, USA. Later he undertook PhD studies at Zurich University Hospital and Tallinn University of Technology and defended a thesis on the topic of hybrid PET/MR imaging. His main research interests are cardiac imaging and hybrid PET/CT and PET/MR imaging. Dr. Šamarin actively contributes to the development of cardiac CT and MR imaging in Estonia. He is currently on the board of the Baltic Society of Cardiovascular Magnetic Resonance.