European Society of Radiology: Could you please give a detailed overview of when and for which diseases you use cardiac imaging?
Eliseo Vañó Galván: First of all I want to thank the Spanish Society of Medical Radiology for nominating me for this interview and the ESR for the great work of preparing IDoR. It is an honour for me.
When we talk about cardiac imaging we include various modalities, and it is fair to say that the most important is echocardiography (normally performed by cardiologists), which should always be the first-line imaging technique for the cardiac patient (used for almost all diseases).
As a radiologist, we may understand cardiac imaging mostly as CT & MRI, and these two techniques are used in an increasing number of indications. The main ones are:
- Ischaemic heart disease: anatomy and pathology of coronary arteries or coronary artery bypass grafting (CABG), ventricular function, rest & stress perfusion and viability
- Planning of transcatheter aortic valve replacement (TAVR) or other procedures such as pulmonary vein ablation, atrial appendage occlusion or cardiac resynchronisation therapy (CRT)
- Myocarditis (actually every patient with suspected myocarditis undergoes a CMR). Oedema can be assessed with T2-mapping, obtaining a quantification that may be used for follow-up
- Valvular heart diseases: aortic valve (stenosis and regurgitation, including the complete study of the aorta and valve morphology, frequently bicuspid valves). Mitral insufficiency, confirming severity and detailing anatomy to help to decide valve repair (including mitraclip) vs replacement. Right valves are also studied with CMR (better visualisation of right chambers)
- Hypertrophic cardiomyopathy, assessing morphology (differential with athlete’s heart), ventricular function, myocardial fibrosis (T1 mapping and delayed enhancement)
- Other various cardiomyopathies, including dilated cardiomyopathy, left ventricular non-compaction, Tako-Tsubo, sarcoidosis, haemochromatosis, confirming diagnosis and assessing prognostic factors
- Suspicion of infiltrative diseases such as amyloid or Anderson-Fabry
- Ventricular tachycardia and arrhythmogenic dysplasia (left and right ventricles)
- Pericardial diseases (most of all effusions and constrictive pericarditis as a differential of restrictive cardiomyopathy)
- Cardiac tumours (benign and malignant)
- Aortic aneurysms and dissections (diagnosis and follow up including post-surgery surveillance)
- Follow up of surgical repaired congenital anomalies
ESR: Which modalities are usually used for what?
EVG:
Cardiac CT:
- Coronary artery disease. In selected patients fractional flow reserve (FFR)-CT may be of invaluable use and will save costs
- Triple-rule-out in the emergency department (all-in-one coronary arteries, pulmonary embolism and aortic dissection imaging)
- Estimating risk of ischaemic heart disease with calcium score in selected patients
- Some cases (mostly diagnosis and post-surgery surveillance) of thoracic aorta diseases
- Planning of procedures
Cardiac MRI:
- Ischaemic heart disease: evaluating ventricular function, rest & stress ischaemia and viability
- Myocarditis
- Valve diseases
- Cardiomyopathies
- Pericardial diseases
- Cardiac tumours (benign and malignant)
- Aortic aneurysms and dissections (mostly follow up, preferred in young patients)
- Congenital anomalies
- Quantification of myocardial iron deposition (T2* mapping)
- Assessment of coronary arteries with MRI: young patients to rule out anomalous origin or proximal disease
I want to remark that there are a few diseases that require both modalities (CT & MRI) such as:
- Some cases of ischaemic heart disease: anatomy with CT +/- FFR-CT and ischaemia with stress-MRI. This technique is normally performed with adenosine but regadenoson is a good alternative drug
- Cardiac tumours: normally we perform both techniques if it is not a typical tumour such as myxoma
- Cardiac calcifications: pericardial disease (constructive pericarditis), atypical mitral annulus calcification
- PET/CT is routinely used for helping in the diagnosis of endocarditis in prosthetic valves.
- SPECT myocardial perfusion (MPI) is still used but it is being displaced by MRI.
ESR: What is the role of the radiologist within the ‘heart team’? How would you describe the cooperation between radiologists, cardiologists, and other physicians?
EVG: The radiologist has a key role in the heart team when interpreting the images of cardiac CT or MRI, but also before the procedure, as we help to get the most of these diagnostic techniques optimising the indications. The cooperation between radiologists, clinical cardiologists, interventional cardiologists, cardiac surgeons and even nurses and radiographers is a basic requisite (I would say a pre-requisite) for a good department of cardiac imaging. We have to learn from each other every day, with an open-minded approach to face the management of the patients in the era of personalised medicine. Official guidelines plus appropriate expert opinions is the winning formula.
ESR: Radiographers/radiological technologists are also part of the team. When and how do you interact with them?
EVG: Also every day. It is not always possible, but I try to include at least one of them in the heart team meetings. Radiographers may potentially influence the technical aspects of the acquisition and the quality of the study which of course will have diagnostic consequences. We also meet in almost every cardiac acquisition: we plan the best options for optimisation (both CT and MRI), and when checking the images, we discuss the quality, the dose (in CT) and the most relevant preliminary findings. Of course, we have a dedicated 3D-lab in which skilled technologists make all the post-processing of cardiac imaging. Motivation (radiologists, cardiologists and radiographers) should be the engine of the ‘quality circle’.
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?
EVG: I am lucky to know the regular working environment in both a big university public hospital (1200 beds) and in a medium-sized private hospital (200 beds) in the capital of Spain:
– In the public hospital, cardiac imaging takes up most of the time. As with many other colleagues, we should better say ‘cardiovascular imaging’ (CVI) as aortic pathology and peripheral non-invasive arterial studies with CTA or MRA also are an important proportion of our activity. There are four radiologists dedicated to non-invasive CVI.
– In the private practice, I combine CVI with leadership, and we are two radiologists (one for congenital and I perform adult studies).
ESR: Do you have direct contact with patients and if yes, what is the nature of that contact?
EVG: Yes, of course. In cardiac CTA I speak with almost every patient, as we briefly interview them, decide on the pre-medication with (or without) cardiologists, reassure them and inform them of what they are going to feel with the contrast and practise how they should hold their breath (this test is a key moment to evaluate the heart rate and decide acquisition method). In MRI I also try to spend at least a minute explaining personally what we are going to do and of course, in stress-perfusion CMR we reassure the patients and explain the informed consent. Moreover, if a patient is especially interested it is not uncommon to discuss radiological findings with them. I treat the patient as I would like to be treated in the same situation.
ESR: If you had the means: what would you change in education, training and daily practice in cardiac imaging?
EVG: In education: I would promote patient-centred medicine (particularly radiology) and multidisciplinary work, teaching a more clinical radiology (this may be the most important hazard of our specialty nowadays, more than the artificial intelligence).
In training: I would establish common basic cardiac imaging training with cardiologists. Most of all I would include echocardiography as part of the training (the same way as ultrasound in abdominal imaging), this way we can know the advantages and limitations of the technique (it is probably the most important one in cardiac imaging). I would also include interventional cardiology as part of the training; where the radiologist would learn among other things, the common language for describing coronary arteries anatomy and pathology.
In daily practice, I would try to extend cardiac imaging with CT and MRI (at least to a basic or medium level) to almost every hospital and form a heart team if it does not exist. This would permit more radiology residents to consider cardiac imaging as a basic part of radiology and not a difficult subspecialty.
ESR: What are the most recent advances in cardiac imaging and what significance do they have for improving healthcare?
EVG: Fortunately, cardiac imaging has evolved in the last few years. We will mention a few remarkable advances that are already being used in several institutions:
- FFR-CT is a promising method of estimating the fractional flow reserve with CTA instead of a wire in the cath lab. This will save several invasive angiograms and reduce costs.
- T1 & T2 mapping: Cardiac multi-parametric imaging has arrived to stay. This is probably the advance that has generated more publications. Tissue characterisation is a huge advantage that differentiates MR from other imaging techniques. With T1 mapping we can predict the prognosis of the patients, as we can quantify the interstitial myocardial fibrosis. With T2 mapping we can quantify oedema in acute myocardial infarction or myocarditis.
- 4D flow: We can study flow in the chest in all directions and predict aortopathy in the era of personalised medicine. These sequences are helping the biomechanical characterisation and may optimise the choice of the moment of surgery, for example in the common aortic bicuspid valves.
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?
EVG: The specialty has changed dramatically. In CT, only a few years ago we had to instruct the patients to perform apnoea and pre-medicated them with high doses of betablockers. Now the whole heart is recorded in a single beat with a sub-milliSievert dose. In MR a lot of sequences have appeared, such as parametric imaging, but also several improvements in the conventional ones, such as delayed enhancement (this last one now is possible in several different flavours: 3D, PSIR, respiratory-navigated and single shot with no breath holding …). 3D printing in cardiovascular diseases has become a reality in several hospitals.
The most important developments in the next ten years in MRI will probably come hand in hand with artificial intelligence and faster imaging techniques such as new-generation parallel imaging. Parametric imaging and one-click quantification will reach full standardisation. Coronary artery imaging will also improve with MRI (now it is possible but sub-optimal in distal segments). It is possible that we will acquire CMR studies in a volumetric fashion of the whole heart (similar to CT), with 4D-flow (morphology, function and haemodynamics) and 3D high resolution delayed enhancement.
In CT the technology will continue improving, coronary CTA will become a routine technique and expand indications (lower doses and better image quality), FFR-CT will be straightforward and spectral imaging will help us to extract more information from our data (including better plaque imaging). CT will also become a one-stop-shop for ischaemic patients with an excellent-quality and low-dose myocardial perfusion imaging, achieving a complete anatomy of the coronary arteries and pointing to the culprit lesion assessing its functional consequences (ischaemia).
We will also see an improvement in hybrid imaging with better equipment for PET/CT and PET/MRI.
ESR: Is artificial intelligence already having an impact on cardiac imaging and how do you see that developing in the future?
EVG: Of course. Maybe we are not aware, but artificial intelligence (AI) is already among us every day. Now, in every radiology department, for example, when we launch coronary extraction, AI makes it possible. As AI and deep learning are generalised, this will improve to an almost perfect coronary extraction, chamber segmentation in CT and MRI; at the end, a fully automated analysis workflow. And also, biomarkers and radiomics. All data will converge: imaging, clinical data, electronic health records and wearables (these are especially important in cardiovascular medicine). I imagine that biobanks, consortia, and the so-called ‘cloud computing’, will be a standard (maybe we will call it ‘heart cloud’?), and big data will be routine. 10–20 years ago the majority of computers did not have an internet connection; now we see that an isolated computer is useless. The same will happen: once we overcome legal barriers, this concept of sharing our data – cloud computing – will be necessary in cardiovascular diseases, in which prognosis factors are the key and where relatively easy patient-specific interventions will save lives.
Prof. Eliseo Vañó Galván is a cardiovascular radiologist, Chairman of the CT & MR Department at Hospital Ntra. Sra. Del Rosario in Madrid, Spain, and collaborating professor of Complutense University of Madrid. He trained in Hospital Clínico San Carlos in Madrid and also was a visiting fellow in cardiovascular imaging at Stanford University Hospital in Palo Alto (California, USA). He has focused on cardiovascular imaging with CT and MRI since 2008, starting new techniques in Hospital Clínico San Carlos and Hospital Ntra. Sra. Del Rosario. His main research fields are structural heart diseases with 3 Tesla CMR as well as strategies to optimise radiation dose in coronary artery CT.
Professor Vañó is an active speaker in cardiac imaging and radiation protection in national and international congresses, is author and co-author of several papers and book chapters, and he has given numerous invited lectures, tutorials and refresher courses at national and international meetings.
He enjoys teaching cardiovascular imaging spanning from the technique to the detail of interpretation and receives several fellows every year.
Professor Vañó is a current member of the executive board of SEICAT (Spanish cardiothoracic imaging society) and the subcommittee for the 2020 Spanish National Radiology Congress.