SA Journal of Radiology - latest Issue
Volume 20, Issue 2, 2016
Author Leonie ScholtzSource: SA Journal of Radiology 20, pp 1 –2 (2016) http://dx.doi.org/10.4102/sajr.v20i2.1045More Less
There is an escalation in the prevalence of cardiovascular disease in sub-Saharan Africa. The radiology community of South Africa plays an important role in curbing this epidemic. Cardiovascular magnetic resonance is now regarded as a very important tool in our diagnostic armamentarium, and in this issue some of the established applications, as well as exciting new developments, are discussed.
Source: SA Journal of Radiology 20, pp 1 –8 (2016) http://dx.doi.org/10.4102/sajr.v20i2.1024More Less
Cardiovascular magnetic resonance (CMR) imaging has gained popularity in the past few years as a reliable, comprehensive assessment tool for the evaluation of patients with congenital and acquired heart disease. However, the overwhelming amount of data generated by CMR makes it difficult to know where to start and what to report. To ensure consistency and reproducibility of CMR reporting, the Society of Cardiovascular Magnetic Resonance (SCMR) Board of Trustees Task Force on Standardised Post Processing has published guidelines to standardise CMR imaging and post processing. The present article aims to provide a pictorial review of these guidelines as well as a framework to basic processing that encompasses: left ventricular function and mass assessment; right ventricular function assessment; atrial size measurements; flow analysis; and T2* analysis and aortic measurements. Cardiac MRI is a robust and rapidly developing field that has significantly advanced the management of cardiac patients. It is important that accuracy and consistency be maintained to ensure that we gain and maintain clinicians’ confidence in the use of this modality.
Source: SA Journal of Radiology 20, pp 1 –8 (2016) http://dx.doi.org/10.4102/sajr.v20i2.1020More Less
Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiac disease. Cardiac imaging plays a key role in the diagnosis and management, with cardiovascular magnetic resonance (CMR) an important modality. CMR provides a number of different techniques in one examination: structure and function, flow imaging and tissue characterisation particularly with the late gadolinium enhancement (LGE) technique. Other techniques include vasodilator perfusion, mapping (especially T1 mapping and extracellular volume quantification [ECV]) and diffusion-weighted imaging with its potential to detect disarray. Clinically, the uses of CMR are diverse. The imaging must be considered within the context of work-up, particularly the personal and family history, Electrocardiogram (ECG) and echocardiogram findings. Subtle markers of possible HCM can be identified in genotype positive left ventricular hypertrophy (LVH)-negative subjects. CMR has particular advantages for assessment of the left ventricle (LV) apex and is able to detect both missed LVH (apical and basal antero-septum), when the echocardiography is normal but the ECG abnormal. CMR is important in distinguishing HCM from both common phenocopies (hypertensive heart disease, athletic adaptation, ageing related changes) and rarer pheno and/or genocopies such as Fabry disease and amyloidosis. For these, in particular the LGE technique and T1 mapping are very useful with a low T1 in Fabry’s, and high T1 and very high ECV in amyloidosis. Moreover, the tissue characterisation that is possible using CMR offers a potential role in patient risk stratification, as scar is a very strong predictor of future heart failure. Scar may also play a role in the prediction of sudden death. CMR is helpful in follow-up assessment, especially after septal alcohol ablation and myomectomy.
Source: SA Journal of Radiology 20, pp 1 –10 (2016) http://dx.doi.org/10.4102/sajr.v20i2.1055More Less
Cardiovascular magnetic resonance imaging plays a central role in the assessment and monitoring of patients with cardiomyopathy. It offers a comprehensive assessment during a single scan setting, with information on ventricular volumes, function and mass as well as tissue characterisation, fibrosis, flow, viability and perfusion. Acute tissue injury (oedema and necrosis) can be distinguished from fibrosis, infiltration and iron overload. It provides information on the cause and prognosis of the cardiomyopathy, and its high measurement accuracy makes it ideal for monitoring disease progression and effects of therapy. The present review highlights the main features of commonly encountered cardiomyopathies in imaging practice.
Source: SA Journal of Radiology 20, pp 1 –8 (2016) http://dx.doi.org/10.4102/sajr.v20i2.1023More Less
The superb spatial and temporal resolution of cardiovascular magnetic resonance (CMR), as well as its reproducibility and independence from patient body habitus and acoustic window, make it an excellent tool for not only diagnostic assessment but also follow-up of valvular heart disease (VHD) patients to determine the optimal time for intervention. This article reviews the anatomy and pulse sequences used to assess these patients and provides an approach for CMR valvular assessment. In addition, it reviews the role of CMR in the assessment of patients with VHD.
Source: SA Journal of Radiology 20, pp 1 –8 (2016) http://dx.doi.org/10.4102/sajr.v20i2.1046More Less
Expanding implantable cardioverter-defibrillator (ICD) indications and significant morbidity and mortality reduction benefits have resulted in a large number of routine ICD implants with appropriate ICD shocks for ventricular arrhythmias. The side-effects and lack of long-term efficacy of antiarrhythmics have made ventricular tachycardia (VT) ablation an increasingly attractive treatment option. Although cardiac magnetic resonance imaging (CMR) is considered the gold standard technique for imaging of myocardial fibrosis to diagnose and guide VT ablation targets in patients with cardiac arrhythmia, safety concerns and significant artifacts from the devices significantly limit the application of CMR. We discuss how to decrease artifact from cardiac devices and the role of a modified inversion pulse late gadolinium enhancement (LGE) CMR sequence as a useful tool in this setting, and we review techniques, safety protocols and limitations from the perspective of our institution’s experience.
Source: SA Journal of Radiology 20, pp 1 –6 (2016) http://dx.doi.org/10.4102/sajr.v20i2.1019More Less
The clinical use of cardiovascular magnetic resonance (CMR) imaging has expanded rapidly over the last decade. Its role in cardiac morphological and functional assessment is established, with perfusion and late gadolinium enhancement (LGE) imaging for scar increasingly used in day-to-day clinical decision making. LGE allows a virtual histological assessment of the myocardium, with the pattern of scar suggesting disease aetiology, and the extent of predicting risk. However, even combined, the full range of pathological processes occurring in the myocardium are not interrogated. Mapping is a new frontier where the intrinsic magnetic properties of heart muscle are measured to probe further. T1, T2 and T2* mapping measures the three fundamental tissue relaxation rate constants before contrast, and the extracellular volume (ECV) after contrast. These are displayed in colour, often providing an immediate appreciation of pathology. These parameters are differently sensitive to pathologies. Iron (cardiac siderosis, intramyocardial haemorrhage) makes T1, T2 and T2* fall. T2 also falls with fat infiltration (Fabry disease). T2 increases with oedema (acute infarction, takotsubo cardiomyopathy, myocarditis, rheumatological disease). Native T1 increases with fibrosis, oedema and amyloid. Some of these changes are large (e.g. iron, oedema, amyloid), others more modest (diffuse fibrosis). They can be used to detect early disease, distinguish aetiology and, in some circumstances, guide therapy. In this review, we discuss these processes, illustrating clinical application and future advances.
Author Benoit DesjardinsSource: SA Journal of Radiology 20, pp 1 –8 (2016) http://dx.doi.org/10.4102/sajr.v20i2.1048More Less
Clinical cardiac electrophysiology is the study of the origin and treatment of arrhythmia. There has been considerable recent development in this field, where imaging has had a transformational impact. In this invited review, we offer a global overview of the most important developments in the use of imaging in cardiac electrophysiology. We first describe the radiological imaging modalities involved in cardiac electrophysiology, to assess cardiac anatomy, function and scar. We then introduce an imaging modality with which readers are probably unfamiliar (electroanatomical mapping [EAM]), but which is routinely used by electrophysiologists to plan and guide cardiac mapping and cardiac ablation therapy by catheter, a therapy which can reduce or even cure arrhythmia. We identify the limitations of EAM and describe how radiological imaging modalities can complement this technique. We then describe and illustrate how imaging has helped the diagnosis of arrhythmogenic conditions, and how imaging is used to plan and guide clinical cardiac electrophysiologic procedures and assess their results and complications. We focus on the two most common arrhythmias for which imaging has the greatest impact: atrial fibrillation and ventricular tachycardia.
Source: SA Journal of Radiology 20, pp 1 –5 (2016) http://dx.doi.org/10.4102/sajr.v20i2.1044More Less
Background: Of all areas worldwide, sub-Saharan Africa is worst affected by the HIV and/or AIDS epidemic. Cardiovascular manifestations are very common and are a powerful contributor to mortality, but often go undetected. Cardiovascular magnetic resonance (CMR) is the most reliable method of assessing cardiac function and morphology and, with this in mind, we initiated a cross-sectional study comparing CMR-determined morphological and functional parameters in asymptomatic HIV-infected patients who were not yet on treatment and early in the disease, with HIV-uninfected control patients.
Objectives: To ascertain whether there were any morphological abnormalities or systolic functional impairments on CMR in untreated asymptomatic HIV-infected patients, compared with HIV-uninfected control individuals.
Methods: The CMR studies were performed using a 1.5-T whole-body clinical magnetic resonance 16-channel scanner (Achieva, Philips Medical Systems, Best, The Netherlands), using a cardiac five-element phased-array receiver coil (SENSE coil). Functional assessment was performed on 36 HIV-infected patients and the findings compared with 35 HIV-uninfected control patients who were matched for age and sex.
Results: There was no significant difference in systolic function between the HIV-uninfected and the HIV-infected patients. The left ventricular end diastolic mass (LVEDM) was slightly higher in the HIV-infected group, but this was statistically insignificant.
Conclusion: No significant differences were found regarding the CMR systolic functional analysis and morphological parameters between the HIV-infected and the healthy volunteers.
Cardiovascular MRI of the pericardium : a case review of the anatomy, scan protocols and pathology of the pericardiumSource: SA Journal of Radiology 20, pp 1 –6 (2016) http://dx.doi.org/10.4102/sajr.v20i2.1022More Less
The aim of this article was to present a case based review of the anatomy, scan protocols and pathology of the pericardium. Cardiovascular magnetic resonance imaging provides excellent anatomic depiction of the pericardium, vital information on myocardial infiltration and characterisation of mass lesions and pericardial effusions. It adds valuable information in the assessment of complicated pericardial disease.