E³ - The Beauty of Basic Knowledge: Cardiovascular and Interventional Radiology

Aortic dissection is the most common acute emergency condition of the aorta, often resulting in the death of the patient. The overall outcome is determined by the type and extent of dissection and the presence of associated complications; therefore, evaluation of the entire aorta, branch vessels, and iliac and proximal femoral arteries is recommended to aid in treatment planning. Early diagnosis and treatment are essential for improving the prognosis. Patients may present with the classic history of acute onset of tearing central chest pain that radiates to the back. Stanford type A dissection involves the ascending thoracic aorta, and the dissection flap may extend into the descending aorta. Type A dissections account for 60%-70% of cases, requiring urgent surgical intervention to prevent extension into the aortic root, pericardium, or coronary arteries. If untreated, type A dissections are associated with a mortality rate of over 50% within 48 hours. Stanford type B dissection involves the descending thoracic aorta distal to the left subclavian artery and accounts for 30%-40% of cases. Management takes the form of medical treatment of hypertension, unless there are complicazioni due to extension of the dissection. CT imaging of the aorta is fast and widely available, which are the important features in making an accurate diagnosis quickly in unstable patients. Multidetector CT allows imaging of the entire aorta with rapid acquisition and data reconstruction to provide prompt and accurate diagnosis and to help identify relevant complications that may have an impact on treatment and management.

Acute aortic dissection represents a life-threatening condition, which must be diagnosed immediately. CTA is considered the imaging modality of choice, offering all relevant information on the pathoanatomy with highest spatial resolution. Stanford classification is used to distinguish between type A- and B-dissections, whereas the left subclavian artery represents the border in between the two types. Actually, surgical repair is the method of choice and indicated in type Adissection, and endovascular repair is the method of choice in type B-dissection, if indicated. Type Bdissection may be uncomplicated or complicated. For uncomplicated type B, best medical treatment is the method of choice, and it is defined by no further symptoms, relief of symptoms and absence of additional dissection associated findings. For complicated type B, endovascular repair including a variety of interventions is the method of choice, and it is defined by mesenterial, renal, peripheral and spinal malperfusion, progressive dissection, aneurysm forming, uncontrollable hypertension, rupture, progressive periaortic and pleural haemorrhage, severe hypotension and shock. Regarding symptom onset and imaging based diagnosis, type B-dissection is classified as acute (<2 weeks), subacute (2-8 weeks), and chronic (>8 weeks). Endovascular repair usually includes prosthesis placement in the descending aorta, in order to seal the proximal entry tear. This excludes the perfusion of the false lumen along the covered aortic segment and restores the blood flow into the true lumen, maintaining and improving the visceral and peripheral perfusion. Additionally, target visceral artery stenting, membrane fenestrating or embolising may be indicated. Protocolled CTA follow-up is mandatory.

The diagnosis of peripheral arterial disease is made on the basis of the typical history and an abnormal ankle/brachial index (ABI). It is important to understand that imaging is only indicated when an invasive intervention is contemplated. Both CTA and MRA are highly reliable methods for depicting vascular anatomy prior to peripheral arterial intervention. Multiple meta-analyses have reported high sensitivity and specificity for the detection of angiographically significant peripheral arterial disease. In my presentation I will discuss imaging protocols and strategies to optimise both techniques in daily clinical practice.

Endovascular therapies are important treatment options in patients with peripheral artery disease. Following regular treatment options like medical therapy and exercise training endovascular therapies have become the first choice in most clinical stages of the disease. While endovascular treatment used to be applied only in limited disease (TASC A/B), endovascular therapies nowadays are often seen as first choice option in almost all stages (TASC C/D). This is mainly due to the successful evolvement of experience of interventional radiologists as well as new developments in endovascular material. Percutaneous transluminal angioplasty (PTA) with plain balloons is usually the first method of choice, while balloons loaded with anti-proliferative drugs such as paclitaxel [drug eluting balloons (DEB)] are often used in restenosis. Stents are commonly used as second option or as first choice in complex lesions. Evidence has to be found when to use drug eluting stents. Stentgrafts are often used in difficult situation when acute bleeding is involved, while scaffolds are often used in long lesions in areas with a lot of movement, in which regular stents would easily be compressed or kinked. This presentation will give an overview about different endovascular techniques including indications when to use which material and provide current evidence.

Magnetic Resonance Imaging (MRI) has recently evolved as a comprehensive modality to provide a reference non-invasive assessment study of cardiac remodeling and dysfunction related to valvular disease, but also to quantify valvular dysfunction - either stenotic or regurgitant valvular lesions - using 2D and 4D phase contrast-based flow imaging. Furthermore, comprehensive vascular assessment such as of the thoracic aorta or pulmonary arterial tree is feasible within a single exam. If MRI is established for the assessment of complex congenital valvular and heart disease it may also be very helpful in case of incomplete or non-diagnostic echocardiography to evaluate valvular disease mechanism, anatomy and quantify disease severity in the more common valvular heart disease settings. Finally, new myocardial mapping tools may provide an insight into myocardial tissue changes including diffuse fibrosis that may be at play in valvular heart disease and precede heart failure. A review of the aforementioned issues and potential value of MRI in valvular heart disease will be provided in this lecture.

Aortic valve stenosis is the most common valvular heart disease in the Western World. When symptomatic, aortic valve stenosis is a debilitating disease with a dismal short-term prognosis invariably leading to heart failure and death. Elective surgical valve replacement is traditionally considered the standard of care for symptomatic aortic valve stenosis. However, several studies have identified various subgroups of patients who have a significant elevated risk for operative complications and death. Accordingly, not every patient is suitable for surgery. Recent developments in transcatheter-based therapies have provided an alternative therapeutic strategy for the non-surgical patient population, replacing the native aortic valve by a bioprosthetic valve brought in place using a non-surgical endovascular or trans-apical pathway. This procedure has been named transcatheter aortic valve replacement or implantation (TAVR, TAVI), or also percutaneous aortic valve replacement (PAVR). Nevertheless, several anatomic and technical criteria have to be fulfilled to safeguard procedural eligibility and success. Therefore, there is a crucial role for non-invasive imaging in both patient selection and subsequent matching to a specific transcatheter valve size, to ensure accurate prosthesis deployment and minimize peri- and post-procedural complications. In this lecture, the relevant anatomy will be reviewed, emphasising anatomic pitfalls, their implications for correct reporting of imaging-derived measurements, and highlighting important differences between imaging modalities. Furthermore, the evolving role of CT-imaging and the role of the radiologist in the triage of patients will be discussed, reviewing current viewpoints in both patient and proper device size selection and the pre-procedural evaluation of the possible access routes.

Evaluation of the extent of atherosclerotic plaque may improve cardiovascular risk stratification in primary prevention. Among the non-invasive measures of atherosclerosis, focus has turned to assessment of coronary calcification by non-contrast-enhanced computed tomography (CT). The calcium score increases with age, and is generally higher for men than for women. The calcium score is divided into 4 categories: 0 (none), 1-99 (mild), 100-399 (moderate), and at least 400 (severe coronary calcification). Another commonly used approach is to calculate an age- and gender-matched percentile. The calcium score is predictive of coronary events in men and women, and in younger and older populations. The relative risks for increasing calcium scores are much higher than those reported for cardiovascular risk factors or other measures of atherosclerosis. Additionally, the absence of coronary calcification indicates a very low risk of cardiovascular disease. According to latest guidelines, calcium scoring should be considered in asymptomatic individuals at intermediate risk based on risk factors. In this group, calcium scoring leads to more appropriate risk classification, into the low- or high-risk group. There is increasing interest in a zero calcium score in patients with chest pain. The presence of >50% coronary stenosis and coronary events was found to be very unlikely in case of a zero calcium score, in both acute and non-acute patients. It seems likely that calcium scoring will play a role in the diagnostic algorithm of patients with chest pain in the future, especially to exclude coronary artery disease.

Cardiac CT angiography has undergone a tremendous development over the last two decades and is diffusing into current medical practice substantially. On the one hand, this can be attributed to emerging scientific evidence demonstrating the incremental value of implementing cardiac CT angiography in diagnostic strategies; on the other hand, the technique itself has become very robust and broadly applicable. Still, performing a cardiac CT angiography requires some basic understanding of the underlying technical principles, physiological circumstances, and the coronary anatomy. The presentation will review available protocols and techniques and provide a straightforward approach to cardiac CTA acquisitions. Practical tips and tricks as well as limitations of the technique will be covered.

Ischaemic cardiomyopathy is the leading cause of morbidity and mortality in the western world. Over the years, several improvements in terms of knowledge, diagnostic capabilities and treatment options have been developed in such a way that today we are in a constant update of our technologies and treatments.
Cardiovascular Magnetic Resonance (CMR) is by far the most flexible and complete imaging modality that can be applied to the evaluation of ischaemic cardiomyopathies. It can provide anatomy, function, flow, ischemia and tissue characterisation. CMR is considered the reference standard for the assessment of inducible ischemia and myocardial viability. Modern MR equipment can deliver a huge amount of information that require wide technical and clinical knowledge to be handled correctly. Especially the newer approaches with quantitative tissue mapping that are being introduced in the clinical field. With the advancement of technology also 3T CMR have become mainstream and able to add some value in certain specific fields. With the rapid growth of Cardiac Computed Tomography as the elective non invasive anatomical tool for the assessment of the coronary arteries CMR becomes the bets tool to complete a Cardiovascular Imaging Section (or viceversa).

Non-ischaemic cardiomyopathies are a heterogenous group of inherited and acquired diseases affecting myocardial function. Cardiac MR is unsurpassed in its ability to quantify myocardial function, identify the pattern and extent of myocardial scar, and access myocardial oedema and diffuse fibrosis. Established techniques such as late gadolinium enhancement are critical to establishing a diagnosis, particularly in differentiation from ischaemic cardiomyopathy. Newer techniques such as tissue mapping are still finding their role in clinical practice, but seem to be promising tools for both diagnosis and prognosis of cardiomyopathies. This lecture will use predominantly case-based discussion to understand the established and evolving imaging biomarkers for non-ischaemic cardiomyopathy and how these are applied in clinical practice. The focus will be on establishing an accurate diagnosis in the major non-ischaemic cardiomyopathies, whilst highlighting areas of diagnostic challenge and uncertainty. The potential of CMR to provide prognostic information and the associated evidence base will also be explored.