Cardiac Computed Tomography for Amyloidosis

Abstract

Purpose of Review Detecting cardiac amyloid (CA) is challenging. Traditional approaches have not always succeeded in achieving a timely diagnosis. Cardiac magnetic resonance imaging (CMR) has begun to change this, but access to CMR may be limited due to availability or contraindications and may not be considered if clinical suspicion is not high. In contrast, cardiac CT (CCT) is widely available, fast, and has few contraindications. In this review, we will consider the role of CCT to identify CA using anatomy, function, and tissue characteristics. Recent Findings We discuss the different CT protocols that have been employed and reflect on the emerging data. Summary It is likely that CCT will complement existing modalities. It will help detect disease sooner and allow therapy to start earlier. Thus, CT may yet shed light on CA and provide a brighter future for patients. Keywords Cardiac CT • Cardiac amyloidosis • CT-derived extracellular volumeThis article is part of the Topical Collection on Cardiac Computed Tomography

Dual versus single energy cardiac CT to measure extracellular volume in cardiac amyloidosis: correlations with cardiac MRI

“…In the present study similar iodine maps were produced by post processing also avoiding projecting sampling volumes from one myocardial volume to another. Projection of a sample volume from contrast to non-contrast and delayed images can be a potential source of error since projecting ROIs in this fashion may lead to the inclusion of non-myocardial tissue in projected volumes [3] It is argued therefore that iodine map reconstructions could theoretically reduce error since iodine map reconstructions calculate virtual non-contrast and post-contrast attenuation values on the same image without the need to project a sample volume between different datasets.…”

“…At present there is no accepted standards for quantifying ECV by CT and no universally agreed protocols [3] . The importance of the current study is to demonstrate that ECV in CA patients can be accurately quantified using both DECT and SECT techniques.…”

“…ECV increases are attributed to localized fibrous scar material, they can also be the result of edema or a more diffuse protein infiltration. Diffuse myocardial protein infiltration characterizes cardiac amyloidosis (CA) [3] . Distinctive, very large increases in ECV are therefore associated with CA and can be of diagnostic utility [4] .…”

“…Iodine contrast media used in cardiac CT is, like gadolinium, water soluble and readily diffuses into the myocardial extracellular space to enable ECV assessment by CT. Measurement of ECV with cardiac CT methods have demonstrated accurate correlation with histology and CMR [3] , [6] . CT is more widely available than CMR.…”