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?
- Cardiovascular Disease – The humble chest x-ray was invented in Scotland’s Glasgow Royal Infirmary in 1896 by Dr. John Macintyre within a few months of Röntgen’s announcement of his discovery and using one of Röntgen’s tubes. Today, the chest x-ray remains a fundamental tool for cardiac evaluation; it is a cornerstone in the evaluation of patients with chest pain and breathlessness and the most commonly performed radiology investigation in the world.
Perhaps ultra-low dose cardiac computed tomography (CT) scans will make inroads and in the future displace the chest radiograph in some scenarios where patients will be proceeding to CT anyway, for example in suspected pulmonary embolism then a ‘contrast-enhanced chest x-ray’ in the form of a CT pulmonary angiogram (CTPA) will be performed.
- Coronary Artery Disease – For coronary artery imaging we use CT angiography (CTA) which is a problem-solving tool for many structural heart problems. In the UK, we are struggling to provide a timely service that would even start to approach the level of activity that meets national guidelines on chest pain management. That is the impetus for my work mapping current UK CT coronary angiogram (CTCA) activity against national benchmarks. Following on from the initial ‘standard setting’ snapshot of activity we have published, we are soon to promote the ‘delta’ evaluation showing the change in activity around the UK, and the British Society of Cardiovascular Imaging (BSCI) and British Society of Cardiac Computed Tomography (BSCCT) is coinciding publicity of this to this year’s IDoR. http://www.bsci.org.uk/standards-guidelines/nice-cg95-update-2016
- Pulmonary Embolism – While the actual incidence of venous thromboembolism (VTE) is not increasing, the demand for objective testing continues to expand as clinical awareness and concerns about the medico-legal implications of missing a VTE diagnosis grow. CT pulmonary angiography is the prime investigation of suspected pulmonary thromboembolism and has in the short course of my consultant career moved from a highly-specialised investigation to a ‘bread-and-butter’ test all radiologists are expected to have competence in. Emphasising the cardiovascular nature of this condition, we have a policy that in all cases of positive CTPA scans comment must be made as to any features of right heart strain, and all cases are also electronically flagged as part of a prospective audit, specifically to allow root cause analysis of Hospital Associated VTE episodes across the Health Board.
- Cardiac Function & Flow – We use MRI for flow evaluation in patients with valvular (particularly aortic) regurgitation and shunts (we seem to see quite a few adults with PAPVD picked up on CT pulmonary angiography) while the follow-up of and monitoring of patients with bicuspid aortic valves and their associated aortopathy is also a growing demand.
- Research Cardiac Imaging – In the research domain, cardiac MRI is answering more refined questions, and I am involved in projects exploring heart failure mechanisms, ventricular remodelling, heart disease in renal failure and the sources of arrhythmic death. Meanwhile, 4D flow technology promises exciting opportunities not only in the heart but for evaluation of many vascular diseases in all body regions.
ESR: What is the role of the radiologist within the ‘heart team’? How would you describe the cooperation between radiologists, cardiologists, and other physicians?
GR: We use both CT and MRI for evaluation of the heart, but echo is the most common primary imaging modality and crucially important for radiologists to understand even if we do not perform it ourselves. We have regular multidisciplinary meetings with the cardiologists and physiologists where we discuss and integrate the information different modalities provide as applied to different clinical problems. This mutual learning allows us to understand the strengths and limitations of each modality as well as putting the imaging in context of the full clinical picture.
ESR: Radiographers/radiological technologists are also part of the team. When and how do you interact with them?
GR: Capturing of images of the beating heart is more challenging than most other imaging, and those radiographers that are interested and have an aptitude for this need to be encouraged. For example, we currently have a small competition to identify the radiographer responsible for the best quality Cardiac CT scan of the month regarding both IQ and radiation dose, with a small prize funded by the consultant team. Support for radiographer training days also helps to encourage interest, and those radiographers who have been on external training are manifestly more proud of their work and in my opinion produce better quality images.
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?
GR: My hospital is a large teaching hospital that also provides general services for the local community. We have four radiologists with cardiac imaging expertise but like in many UK centres none of us do cardiac imaging exclusively but rather as part of wider practice, most commonly combined with other thoracic and vascular imaging. I am an expert in non-invasive vascular imaging for all parts of the body (MRA and CTA) including stroke and VTE while contributing to acute/unscheduled care imaging of all body areas supervising acute CT and MRI lists and when on-call.
ESR: Do you have direct contact with patients and if yes, what is the nature of that contact?
GR: My main interaction with patients needing cardiac imaging revolves around preparation for CT with i.v. beta blockade. When I have the time then I do enjoy providing immediate preliminary feedback to the patient as to the success of the scan and in general terms my initial findings though with the caveat that I have only reviewed things quickly on a small screen and that time carefully reviewing the scan on a sophisticated workstation will be needed for the full detailed report.
ESR: If you had the means: what would you change in education, training and daily practice in cardiac imaging?
GR: I firmly believe that cardiac radiology is coming out of the shadows and needs simply to be seen as routine part of the everyday radiological activity and if we are to meet the challenge of the UK national guidelines (NICE) – nothing less is acceptable. As such I believe that cardiac imaging training must start right at the beginning of general radiological training, not only with good teaching on chest radiograph interpretation but also bringing the performance and interpretation of CT coronary angiography into core training. This is why the BSCI/BSCCT has submitted a revised curriculum to the Royal College of Radiologists in which CTCA has been made a core skill.
Over and above this, we have to fight to ensure that cardiovascular imaging is appropriately recognised and resourced, in my opinion it is fundamental ‘life and death’ imaging and must take precedence over the rising tide of ‘wear and tear’ imaging that has no impact on mortality. After all, the SCOT-HEART study under Prof Dave Newby’s direction has shown that the use of coronary CTA actually saves lives. As far as I know, this is the first time that this kind of hard outcome has been shown in a prospective RCT for any of the radiological tests we do!
ESR: What are the most recent advances in cardiac imaging and what significance do they have for improving healthcare?
GR: For CT the most significant is the advent of wide detector systems and other innovations that allow us to image the technically ‘difficult’ patient such as those in atrial fibrillation all the while with increasingly low radiation dose. The focus cardiac CT has brought to bear on radiation dose reduction is starting to benefit all patients undergoing CT, for example as the use of iterative reconstruction techniques are applied to other areas of the body. The BSCI/BSCCT audit has been responsible for setting a new national dose reference level.
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?
GR: Cardiac radiology has in some ways changed beyond recognition since I started as a consultant and is now, I believe, entering a golden era where sophisticated imaging that is rich in information has never been so easy to acquire. The information overload is probably the most pressing problem now, and tools to automatically extract that data and rapidly present it in digestible form via AI tools is where I would like to see most progress.
ESR: Is artificial intelligence already having an impact on cardiac imaging and how do you see that developing in the future?
GR: AI is only just beginning to help us with much-increased automation of analysis software – I am really looking forward to not having to draw circles on CMR images after 20 years! I believe the advent of systems that can link discrete tasks together will allow not only increased productivity but enhanced quality and reliability. For example, separate tasks such as automated calcium burden assessment on enhanced CT scans, coronary tree analysis with indicators of coronary functional flow characteristics, cardiac chamber sizes and myocardial mass, thoracic aortic dimensions, lung nodule and texture analysis etc. could have their results presented automatically allowing the clinical radiologist to synthesise the various findings into appropriate clinical context.
When I was a young doctor, I would have to call out a consultant haematologist to perform a differential white cell count in the night if it was really, really needed. This is now all automated, but consultant haematologists are still busy people involved in QA of their systems, ensuring their labs are used correctly in clinical pathways and giving valuable opinions in difficult cases. I believe this is how radiologists will evolve away from the tedium of tasks such as ‘spot the nodule’, which we will not do well if bored and overwhelmed by excessive workload.
Dr. Giles Roditi is the President of the British Society of Cardiovascular Imaging and a consultant cardiovascular radiologist in NHS Greater Glasgow & Clyde. He is also an Honorary Clinical Associate Professor of Radiology at the University of Glasgow. Dr. Roditi first became involved with cardiac MRI during training in Aberdeen in 1993 and gained further experience in CMR techniques as visiting Fellow at Harvard University, Boston in 1994. He has worked at Glasgow Royal Infirmary since 1997, with particular interests in cardiac MRI, cardiac CTA, renovascular imaging, lower limb MRA techniques, carotid MRA and venous imaging. He is the current Chair for Contrast Procurement in Scotland & Northern Ireland and has also been involved with the RCR Standards for Intravascular Contrast Administration to Adult Patients.