Interventional radiology (IR) is a branch of clinical radiology utilising minimally-invasive image-guided procedures to diagnose and treat diseases.
To become an interventional radiologist, you should apply for ST1 clinical radiology training i.e. both interventional and non-interventional radiologists undertake the same initial training. There are small regional variations in training structure, but in general you will spend 3 years doing general diagnostic radiology (during which many schemes include 3-4 months of IR training), followed by 3 years of sub-speciality interventional radiology training, giving a total of 6 years training (1 year longer than diagnostic clinical radiology training).
What is interventional radiology? (thanks to BSIR)
Interventional radiology is generally sub-divided into into neuro IR and body/vascular IR. A minority of consultants perform a mixture of the both, but to my knowledge there are currently no training schemes which include both. This may change in the future with the increasing use of mechanical thrombectomy for stroke treatment. A large number of interventional radiologists will be needed to run this service and with no concurrent increase in the number of elective IR procedures, many centres will need to train body interventionists to undertake neuro intervention to help fill gaps in stroke thrombectomy rotas.
As far as body intervention goes (the majority of IR), there are a large range of procedures as follows:
Vascular IR covers approximately 60 % of the work of interventional radiology. Most IR consultants call themselves vascular and interventional radiologists. The work is split up into:
Diagnostic vascular imaging: MRI, CT, arterial Duplex, diagnostic angiography (which is becoming less common with improvements in cross-sectional imaging) and rarely PET CT.
Peripheral vascular disease: Diagnostic angiography, angioplasty and stenting. Emergency work includes thrombectomy/thrombolysis for acute arterial and venous thrombosis.
Aortic procedures: Infra-renal Endovascular Abdominal Aortic Aneurysm Repair (EVAAR), thoracic endovascular aortic repair, complex aortic repairs including fenestrated aneurysm repairs, thoraco-abdominal branched repairs, iliac branched repairs and complex thoraco-abdominal hybrid procedures usually for complicated aortic dissections. Emergency work includes EVAAR for aortic rupture (either traumatic or as a result of aneurysm).
Visceral arterial work: Treatment of visceral aneurysms with either embolisation or exclusion with stent grafts. Visceral arterial stenting for ischeamia.
Treatment of bleeding: e.g. from the GI tract, elective uterine fibroid embolisation or as an emergency in postpartum haemorrhage or traumatic arterial bleeding embolisation.
Urology work is the second largest branch of IR.
Treatment of urinary obstruction: Nephrostomy and ureteric stenting. This is performed in almost all IR units.
Treatment of high burden of renal stone disease: Percutaneous Nephro-lithotomy (PCNL), only performed at specialist centres.
'Renal denervation' artwork by Jim Zhong, Radiology registrar, Leeds (UK)
Hepatobiliay work is generally higher risk than urological work and is less common, so is generally only performed at larger centres.
Treatment of biliary obstruction: External biliary drains and biliary stenting.
Trans-Jugular Intrahepatic PortoSystemic Shunting (TIPSS): Performed at specialist centres for portal hypertension causing bleeding or intractable ascites.
This is a huge growth area (no pun intended) in IR. Techniques are relatively new and indications expanding.
Ablation: There are several competing technologies used to ablate tumours including radiofrequency ablation, microwave ablation and cryoablation. Tumours commonly ablated include, lung, liver, renal and bone.
Embolisation: Either for symptom relief (e,g bleeding renal tumour) or for therapy as in hepatocellular cancer, this can involve bland (plastic/glass beads) or with particles impregnated with chemotherapy agents allowing high doses of chemotherapy to be targeted accurately at tumours.
Selective internal radiotherapy (SIRT): A form of brachytherapy where either a whole organ or part of it can be targeted with radioactive particles. Most commonly the liver for inoperable HCC or metastaic colorectal cancer.
Biopsy and drainage:
Many people do not consider biopsy as interventional radiology as it is a diagnostic rather than therapeutic procedure, however a significant proportion of biopsies are performed by interventional radiologists.
Percutaneous biopsy: Most commonly ultrasound guided, rarely CT or MRI guided.
Trans-jugular biopsy: Biopsy of the liver or kidneys. Usually performed by an interventionist in patients with ascites or coagulopathy.
Percutaneous drains using ultrasound or CT guidance.
Interventional radiologist performing a CT guided para-aortic lymph node biopsy
How to Apply for IR
If you want to become an interventional radiologist you will first need to get onto a clinical radiology training programme. If you know you want to do IR when you are applying for radiology, make sure that you aim for a training scheme that offers good sub-speciality IR training (not all of them do and even those that do may not offer the whole range of IR procedures). If you get on a scheme that does not offer IR sub-speciality training it may be possible to transfer to another, but this could be disruptive or difficult.
Whilst in clinical radiology training you will generally have 2.5 years to decide which sub-speciality you want to do. This means that about half-way through your 3rd year of training you will usually get the chance to choose IR. Most people will not have to compete for IR training, but occasionaly this could be a competitive process depending on how many people in your year group want to do IR training. Most schemes will usually work hard to provide you with training at a nearby institution if they cannot train you at their own.
There are many on a whole range of IR topics. As a start we would recommend:
Chapman & Nakielny's Guide to Radiological Procedures (7th Edition)
Nick Watson, Hefin Jones
The concise guide to all the common procedures in imaging on which a radiology trainee will be expected to be familiar.
Interventional Radiology: A Survival Guide (4th Edition)
David Kessel, Iain Robertson
A week in the life of an IR trainee
I am an ST6 IR trainee and I am very lucky compared to other trainees. In a typical week I will have 1 day of service (general radiology work covering CT, ultrasound or plain films) and 4 days when I can do whatever I want for my training needs! This usually includes 1-2 morning performing EVAR in the operating theatre, 1 afternoon reporting vascular imaging or preparing for the vascular MDT, and the remaining 2.5 days in the angio suite performing a range of vascular, urological, biliary and oncology procedures.
Compared to surgery or medicine the time of an IR trainee is mainly spent on training not service provision hence the ability to learn a whole range of procedures and skills in a short time (only 3 years of specific IR training). I also take part in an on-call rota (1 week every month) and there is always a consultant on-call with me, who will supervise me for almost any procedure.
A week in the life of an IR consultant
As you may know a full time consultant contract is split into sessions (a morning or afternoon of work, 4 hours long).
A typical IR consultants timetable:
- 3 sessions in the IR suite
- 1 session in theatre (EVAR or interventional oncology)
- 1 session vascular MDT
- 3 sessions general radiology reporting (CT, US, MRI, plain films etc)
- 1.5 sessions SPA
- 0.5-1 session for on-call commitments
Recommended websites to find out more
- British society of interventional radiology
An excellent resource to find out about courses, conferences, essay prizes, bursaries and training opportunities. Become a member and you will also get access to the CVIR journal and ESIR website (see below). Look up the training committee and get involved! You can join as a student, junior doctor, or radiology trainee.
- European society of radiology
An excellent resource for cutting edge technologies and evidence base. I personally recommend the videos of almost all the talks from the annual CIRSE conference, delivered by world leading interventionists.