Introduction

Endomyocardial fibrosis (EMF) is a chronic restrictive cardiomyopathy involving abnormal scarring and thickening of the endocardium (the innermost heart lining). Over time, fibrosis makes the ventricles rigid, making it difficult for the heart to fill properly. This leads to arrhythmias, heart failure, and, in severe cases, sudden death. EMF is considered one of the most neglected cardiovascular diseases despite being the leading cause of restrictive heart disease in tropical regions such as parts of South America, South Asia, and sub-Saharan Africa.¹

EMF is frequently underdiagnosed, and it is therefore challenging to estimate the real global numbers of people affected. This challenge is particularly true in low-resource areas where healthcare access and imaging technologies are scarce. Various studies suggest the prevalence rates are as high as 10–20%, especially in rural areas of Africa.² Furthermore, EMF has a significantly greater impact on children and young adults, but the most prominent range falls in between those aged 10–40, resulting in lasting social and economic effects on impacted families and communities.³

Even though EMF was acknowledged more than 55 years ago, professionals still don't quite comprehend it well. EMF can resemble other symptoms relating to different conditions of heart failure. Imaging techniques allow us to confirm the presence of EMF. If professionals can differentiate EMF from other conditions, it will result in the appropriate approach and treatment being implemented for the individual's needs.

Echocardiography and cardiac magnetic resonance imaging (CMR) have been traditionally used for evaluation. However, in advanced cases where structural changes are more pronounced, computed tomography (CT) offers unique diagnostic and management advantages. This article explores the specific utility of CT imaging in advanced EMF, its role compared with other modalities, and future perspectives in the field.

Pathophysiology and Clinical Features of EMF

The pathogenesis of EMF remains incompletely explained due to its complexity, but there are a few suggestions:

• Eosinophilia: High eosinophil counts (often due to immune responses or parasitic infections) release toxic proteins, which can damage the endocardium
• Chronic inflammation: Progressive fibrosis can be driven by repeated myocarditis or environmental triggers
• Nutritional and socioeconomic factors: Diets low in protein or high in toxic components such as cassava have been linked to EMF in endemic regions
• Genetic predisposition: Familial clustering suggests a possible hereditary component in some populations³

Stages of Disease

Clinically and pathologically, EMF can be divided into three stages:

• Acute inflammatory stage – fever, eosinophilia, and myocarditis-like symptoms
• Thrombotic stage – mural thrombi (clots) develop on injured endocardial surfaces
• Fibrotic stage (advanced EMF) – Thick scar tissue substitutes endocardium and myocardium, filling the ventricular apex, altering valve structures, and frequently resulting in calcification

Many individuals in the advanced fibrotic stage frequently find that their ventricles cannot adequately expand to receive blood, leading to significant restrictive physiology. Symptoms related to this condition consist of dyspnea (shortness of breath), fatigue, peripheral oedema, and ascites (abdominal swelling due to fluid). Regurgitation of valves (especially mitral or tricuspid) and arrhythmias add complexity to the clinical scenario.⁴ Because these symptoms mimic other cardiac diseases, imaging becomes the cornerstone of diagnosis.

Traditional Imaging Modalities and Their Limitations

Echocardiography (Echo)

Echo is typically the first-line test. It provides functional information on chamber sizes, wall motion, filling patterns, and valve competence. Hallmark echo signs of EMF include apical obliteration and restrictive filling patterns. Contrast echocardiography can also improve thrombus detection. However, echo has drawbacks: it is heavily operator-dependent, image quality is limited by body habitus or acoustic windows, and distinguishing thrombus from fibrosis or calcification is difficult.⁵

Cardiac MRI (CMR)

CMR offers superb soft tissue contrast. Late gadolinium enhancement (LGE) highlights areas of fibrosis; parametric mapping techniques can quantify extracellular volume (ECV), giving detailed insights into disease severity.¹ However, limitations include:

• Accessibility: MRI machines are scarce in many EMF-endemic regions
• Patient restrictions: unsafe in patients with some metal implants or severe renal dysfunction (which makes gadolinium unsafe)
• Practicality: scans take longer, require patient cooperation, and are more expensive than echo or CT

These gaps underscore the value of CT, particularly for advanced EMF, where calcification, thrombus, and valve involvement are common.

The Role of CT Imaging in Advanced EMF

CT imaging has become an increasingly important diagnostic tool in cardiology. In advanced EMF, its role is particularly strong because of the following strengths:

Technical Aspects

Modern ECG-gated CT allows for sharp imaging of cardiac structures as it reduces motion artefacts. Intravenous contrast clearly delineates the myocardium, chambers, and highlights any abnormal masses. Multiplanar reconstructions provide 3D perspectives, essential for evaluating complex anatomic changes.

Advanced protocols, such as dual-energy or photon-counting CT, further enhance tissue characterisation, and research suggests they can approximate MRI’s capability in differentiating fibrosis from thrombus.⁶

Characteristic CT Findings in Advanced EMF

• Endocardial thickening: visible irregular thickening along ventricular walls
• Apical obliteration: the apex of the ventricle is completely obliterated by fibrotic tissue or thrombus
• Mural thrombus: non-enhancing masses within ventricles; CT differentiates these from scar tissue
• Calcification: highly conspicuous on CT, unlike echo or MRI
• Valve involvement: tethering or distortion of atrioventricular valves (mitral or tricuspid) due to adjacent fibrosis⁷

Clinical Scenarios Where CT Excels

• Pre-surgical planning: For patients evaluated for endocardectomy or valve replacement, CT offers accurate anatomical information to assist surgical teams
• Stroke prevention: Identifying mural thrombi can guide anticoagulation methods, reducing the risk of embolism²
• Differential diagnosis: CT aids in differentiating EMF from constrictive pericarditis (characterised by pericardial thickening or calcification) or infiltrative cardiomyopathies (which exhibit distinct patterns)
• Monitoring disease progression: CT can monitor changes in calcification or thrombus size over time, providing a non-invasive method when MRI is not accessible⁸

Advantages and Limitations of CT

Advantages:

• Unmatched ability to detect calcification
• High-resolution anatomical imaging
• Faster scan times than MRI
• Increasingly available in many middle-income countries
• Useful alternative when MRI is contraindicated⁹

Limitations:

• Radiation exposure, though modern scanners reduce this risk
• Contrast use: potential for kidney injury or allergic reactions
• Less sensitive than MRI for subtle fibrosis without calcification
• Cost and availability still vary across low-income, rural areas where EMF is most common

Future Perspectives

CT is evolving rapidly. The next generation of photon-counting detector CT (PCD-CT) offers ultra-high resolution at lower radiation doses and can differentiate tissue types more precisely.⁶ Spectral CT could enable improved differentiation between fibrosis and thrombus. AI algorithms are being created to automate the identification of EMF characteristics, which could lower reporting inconsistencies and allow screening in resource-limited environments.

Aside from technology alone, healthcare equity is a vital concern. Communities in rural or low-income tropical areas are heavily impacted by EMF. These areas lack the necessary equipment, such as MRI machines, which are uncommon to see, and advanced imaging resources are limited. CT scanners are expensive, but these are becoming increasingly available in secondary-level hospitals throughout Africa, South America, and Asia. If local radiologists and cardiologists could be educated and trained to identify EMF-specific CT patterns, this would enable more timely and precise diagnosis.

Over time, developing standardised CT protocols designed for EMF in endemic areas would decrease discrepancies among centres. International partnerships and public databases may enhance diagnostic standards, elevate patient results, and bridge the divide between affluent and under-resourced environments. In this context, the future of CT in EMF includes not only improved imaging but also promoting access, understanding, and equity.

Summary

Endomyocardial fibrosis continues to be a severe, often overlooked condition, especially in tropical regions. Imaging plays a crucial role in diagnosis and treatment, as each type provides distinct advantages. Although echocardiography and MRI hold significant value, CT offers unparalleled anatomical detail in advanced conditions, particularly for identifying calcifications and thrombi and for surgical planning.

With advancements in technology and increased accessibility, CT has the potential to become a key imaging technique for EMF, serving as a link between resource-rich and resource-limited environments. Currently, its main significance is found in advanced EMF, where structural alterations are most evident and clinical choices are most crucial.

Frequently Asked Questions (FAQ)

What is endomyocardial fibrosis?

 A disease where scar tissue builds up inside the heart, making it stiff and unable to fill properly.

Why is imaging important for EMF?

 Because symptoms resemble other heart conditions, imaging is needed to confirm the diagnosis and guide treatment.

Why use CT instead of MRI?

MRI shows fibrosis well, but CT is faster, more widely available, and better at showing calcification and clots.

What can CT show in advanced EMF?

Thickened endocardium, obliterated apices, calcifications, thrombi, and valve distortion.

Can CT replace other tests?

No. CT complements echo and MRI, each giving unique information.

What’s the future of CT in EMF?

Photon-counting CT, spectral imaging, and AI tools may improve precision, while efforts focus on making imaging accessible in endemic regions.