European Society of Radiology: Could you please give a detailed overview of when and for which diseases you use cardiac imaging? Which modalities are usually used for what?
Norzailin Abu Bakar: Here are the common conditions which cardiac computed tomography angiography (CTA) is used for:
- Ruling out significant luminal stenoses in stable patients with suspected coronary stenoses, but intermediate pre-test likelihood of disease
- Ruling out coronary artery disease in acute chest pain
- Coronary anomalies
- Ruling out stenoses before non-coronary cardiac surgery
- Determine the patency of coronary artery bypass grafts
- Using CT as an alternative when cardiac catheterisation is impossible or carries a high risk
- Clarifying unclear findings after invasive angiography
- Providing peri-interventional information for percutaneous coronary intervention
- Assessing coronary artery stents
- Determining the presence and extent of coronary atherosclerotic plaque
Common conditions which cardiac magnetic resonance imaging (MRI) is used for include:
- Assessment of myocardial function following myocardial infarction
- Assessment of myocardial viability/hibernation
- Myocardial perfusion
- Congenital heart disease
- Valvular disease
- Pericardial disease
- Myocardial tumour
- Clinical research
ESR: What is the role of the radiologist within the ‘heart team’? How would you describe the cooperation between radiologists, cardiologists, and other physicians?
NAB: Cardiac radiologists are doctors who use imaging techniques such as x-rays, ultrasound, CT, positron emission tomography (PET), nuclear medicine, magnetic resonance angiography, and MRI to diagnose heart and vascular disease. Using these diagnostic tests, cardiac radiologists together with other physicians can screen for heart disease or diseases of the blood vessels, determine what is causing a patient’s symptoms, and monitor patient disease and determine if treatment is working.
ESR: Radiographers/radiological technologists are also part of the team. When and how do you interact with them?
NAB: The radiography workforce is a vital part of the specialist cardiac team, providing rapid access to a range of high quality and appropriate imaging during a critical period of the care pathway. Radiographers have developed their clinical practice in a variety of complex procedures, improving outcomes for patients with, or at risk of cardiovascular disease. I usually discuss the cases with my radiographers before CT or MRI is performed, explaining what I am looking for in specific cases. This previous talk encourages them to do their job and understand the case. Teamwork is very important to get a good result. If they made a mistake, it’s good to explain to them what they did wrong, so that they don’t repeat it in the future.
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?
NAB: Being in a university hospital, cardiac imaging only takes up part of my regular work schedule. Besides clinical cardiac imaging, I also give lectures in cardiac imaging to postgraduate students, undergraduate medical students and radiographers. Currently, I am the only cardiac radiologist in my team, which also includes four dedicated cardiac MRI radiographers and four dedicated cardiac CT radiographers.
ESR: Do you have direct contact with patients and if yes, what is the nature of that contact?
NAB: Yes I do, usually before and after the examinations are carried out. Before the examinations, I usually explain the examination to them and try to obtain more information about their condition. After the examination, I give further explanation or answer any of their questions if needed.
ESR: If you had the means: what would you change in education, training and daily practice in cardiac imaging?
NAB: Future radiologists should be trained in all cardiac imaging modalities so that more will choose cardiac imaging as their subspecialty. Traditionally, cardiac imaging training has focused on clinical applications of existing technology in patient care. Although clinicians can readily identify clinical needs, nonclinical scientists and engineers have a better foundation for developing the technology to meet these needs. However, these two groups often have limited interactions. Thus, a challenge exists in the identification and articulation of unmet clinical needs and their translation into innovation and technology development, which could be addressed by improving bidirectional communication between clinicians and scientists/engineers.
Collaboration between the industry, engineers and clinicians is hampered by a number of considerations, including the development of individual imaging modalities in silos and the lack of formal training in research/innovation for radiologists. Although the primary objective of medical training is to gain clinical expertise, medical school, residency and fellowship can all provide opportunities to learn to think creatively and interact with experienced mentors. This is especially true for cardiac imaging fellowships.
ESR: What are the most recent advances in cardiac imaging and what significance do they have for improving healthcare?
NAB: In the past years, there have been significant advances in cardiac imaging modalities.
For example, advances in cardiac MRI with T1 mapping now allow quantification of extracellular volume fraction (ECV), by exploiting the extracellular nature of gadolinium. Understanding the role of increased ECV in various disease states may provide a new method to assess prognosis and aid in the development of novel therapeutics.
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?
NAB: The diagnostic and prognostic utility of CMR continues to evolve, with new techniques providing novel insights into cardiac pathophysiology and unprecedented tissue characterisation of the myocardium. Novel acquisition strategies combined with advanced reconstruction techniques are enabling high-resolution, truly 3D dynamic acquisitions, which will be the future of CMR. The recent development of fast T1, T2 and T2* mapping techniques are rapidly entering the clinical CMR arsenal of techniques for tissue characterisation. T1 mapping combined with GBCAs enables in vivo assessment of ECV, which is finding applications in multiple cardiac pathologies.
ESR: Is artificial intelligence already having an impact on cardiac imaging and how do you see that developing in the future?
NAB: Artificial intelligence (AI) has captured the imagination and attention of doctors over the past couple of years as several companies and large research hospitals work to perfect these systems for clinical use. One of the most active areas of research in applying deep learning to cardiac imaging is in segmentation – the task of identifying which pixels in a medical image correspond to the contour or interior of a particular anatomic region of interest, e.g. isolating the outline of a particular organ from an MRI scan.
AI will play a key role in the future. AI will not diagnose patients and replace doctors – it will improve their ability to find the key, relevant data they need to care for a patient and present it in a concise, easily digestible format. When a radiologist calls for a chest CT scan to read, AI will review the image and identify potential findings immediately – from the image and by combing through the patient history related to the area scanned. For example, if the exam order is for chest pain, the AI system will call up:
- All the relevant data and prior exams specific to prior cardiac history
- Pharmacy information regarding drugs specific to COPD, heart failure, coronary disease and anticoagulants
- Prior imaging exams from any modality of the chest that may aid in diagnosis
- Prior reports for that imaging
- Prior thoracic or cardiac procedures
- Recent lab results
- Any pathology reports that relate to specimens collected from the thorax
Artificial intelligence or machine learning software will serve as a very experienced clinical assistant, augmenting the doctor’s capacity and making workflow more efficient.
Dr. Norzailin Abu Bakar is a cardiac radiologist and senior lecturer at Universiti Kebangsaan Malaysia Medical Centre in Kuala Lumpur, Malaysia. She trained in Kuala Lumpur in general radiology and in cardiac radiology. Since 2008 she has been an active researcher in multimodality cardiac radiology, with a special interest in MRI. She has supervised the development of cardiac computed tomography and cardiac magnetic resonance at Universiti Kebangsaan Malaysia Medical Centre. Dr. Norzailin Abu Bakar has authored or co-authored more than 15 peer-reviewed publications and has given numerous invited lectures, tutorials and refresher courses at national meetings. She is also involved in international meetings. She currently serves as the head of the cardiac imaging group in the Malaysian College of Radiology and she is also the executive member representing Malaysia in the Asian Society of Cardiovascular Imaging (ASCI).