Introduction 

Endocardial Fibroelastosis (EFE) is a rare heart condition that causes the endocardium to increase in thickness due to an accumulation of elastic and fibrous tissue and can result in heart failure. This condition is most commonly present in infants and is rare in adults. EFE may be triggered by viral infections, immune or genetic factors. Echocardiography (‘echo’) and electrocardiography (ECG) are most commonly used in the diagnosis of EFE.

This condition can present without any structural abnormality of the heart, however, lesions of the left ventricle, such as a hardening of the aortic valve (aortic stenosis), are common. Surgical intervention involving the removal of fibrous tissue in one or both ventricles is the treatment of choice. However, surgical resection of EFE requires a greater certainty of the diagnosis and of the extent of fibrous tissue accumulated than echocardiography can provide.

Endocardial biopsy can be used to diagnose EFE, however, it is highly invasive. Therefore, minimally invasive imaging such as cardiac computed tomography (CT) and magnetic resonance imaging (MRI) is being used to obtain an early and accurate diagnosis due to the rapid onset and poor prognosis of EFE. In cases where diagnosis is difficult, cardiac CT combined with MRI can provide information on ventricle wall thickness and function, helping to confirm an EFE diagnosis. This article will discuss the advantages and disadvantages of both MRI and cardiac CT in the evaluation of EFE and how they can be used in combination to aid in a treatment plan for EFE.^1,2,3,4

MRI in the evaluation of EFE

MRI scans can precisely identify anatomical changes in the heart and evaluate cardiac function. MRI can make a good assessment of both cardiovascular physiology and anatomical detail, which is essential for selecting therapies and determining prognosis. Due to MRI’s high spatial and tissue resolution, EFE can be distinguished from other cardiac disorders, such as left ventricular noncompaction (LVNC), due to the ability of MRI to clearly show the border between the lining of the heart, the endocardium, and myocardium. Continued evaluation of EFE using MRI over time can provide a non-invasive assessment of disease progression and treatment efficacy. 

Another advantage of MRI is the absence of contrast-induced nephropathy (CIN), meaning lessened damage to the kidneys and radiation exposure. It serves as an option for patients with renal insufficiency or who are concerned about the hazards associated with iodinated contrast. 

While MRI has many advantages in the evaluation of EFE, it also has limitations due to high costs and long examination times. A further limitation of MRI in the evaluation of EFE is that patients with metallic implants such as pacemakers or internal defibrillators will not be able to get the scan.^1,4,5,6,7

Cardiac CT in the evaluation of EFE

Cardiac CT scans can detect cardiovascular calcification and rule out pericarditis non-invasively. CT's advantages include its high spatial resolution, quick scan times, and software that allows you to see images in any plane. CT is able to provide highly accurate measurements of myocardial thickness. 

Cardiac CT also provides excellent visualisation of the airways, bones, and soft tissues. This wide field of view allows for the evaluation of surrounding structures, which can be important when EFE is being considered as a potential diagnosis in a differential diagnosis. It is also more suitable for patients with pacemakers and internal defibrillators than MRI.

A significant limitation of CT scans is that ionising radiation is used, increasing the risk of malignancy, which is a considerable concern, especially for paediatric patients who are more vulnerable to radiation-induced damage due to their tissues still growing and a longer lifespan.

Sedation and anaesthesia carry their own potential short- and long-term risks, including potential for neurotoxicity of anaesthetic agents in young children. While both imaging techniques require patients to stay still for a clear image, MRI is more likely to require this due to the longer duration needed for the scan to be complete.^1,6,7

Management

Patients will require regular follow-up imaging and consultations with a multidisciplinary team to monitor disease progression and manage any complications that may arise. People with EFE caused by genetic reasons may benefit from genetic counselling, which may be beneficial for families in future pregnancies.⁸

Future directions

Artificial intelligence (AI) and machine learning in cardiac CT and MRI cardiovascular studies have been found to improve clinical workflow and patient outcomes. This could increase cardiovascular risk prediction in patient groups and facilitate preemptive treatment through the use of cardioprotective medications.

Advanced AI improves image quality with lower radiation doses, benefiting vulnerable groups like children by enhancing diagnostics and reducing radiation risks. The ability to improve diagnostic outcomes while minimising radiation exposure may enable safer imaging, reducing the long-term risks associated with ionising radiation. 

Contrast echocardiography is a technique which has shown significant advantages in the diagnosis and treatment of EFE. Compared to CT and MRI, it is fast, effective, well-tolerated and inexpensive.^9,10,11

Summary

EFE is a rare but life-threatening condition that requires accurate and early diagnosis along with careful monitoring to guide treatment. While echocardiography remains a useful first-line tool, its limitations highlight the importance of advanced imaging techniques. MRI provides excellent assessment of cardiac function and tissue characterisation without radiation, while cardiac CT offers rapid, high-resolution structural imaging and the ability to detect calcification. Each method has advantages and limitations, and in many cases, they are best used in combination to achieve a comprehensive evaluation. Emerging tools such as artificial intelligence and contrast echocardiography hold promise for improving diagnostic accuracy, reducing risks, and expanding access. Ultimately, MRI and CT in combination are essential to enhancing early detection, guiding clinical decision-making, and improving long-term outcomes for patients with EFE.