The Use of Multimodality Imaging for the Diagnosis of Myocardial Outpouchings and Invaginations: A Systematic Review

Abstract

Cardiac ventricular outpouchings and invaginations are rare structural abnormalities and usually incidental findings during cardiac imaging. A definitive diagnosis is possible through the use of multimodality imaging. A systematic review of the literature was carried out in November 2022 to identify studies regarding ventricular outpouchings and invaginations. The main aim of the review is to summarize knowledge regarding epidemiology, etiology, diagnosis and prognosis of patients with ventricular outpouchings (aneurisms or diverticula) and invaginations (crypts and recesses). Overall, 26 studies published between 2000 and 2020 were included in the review. Diverticula and congenital aneurysms incidence ranges between 0.6 and 4.1%. Myocardial recesses and crypts range between 9% in the general population and up to 25% in patients with hypertrophic cardiomyopathy. The combined use of echocardiography, cardiac computed tomography (CCT) and cardiac magnetic resonance (CMR) is useful to establish tissue contractility, fibrosis, extension and relationship with adjacent structures for differential diagnosis of both invaginations and outpouchings. In conclusion, both outpouchings and invaginations are rare entities: a definitive diagnosis may be aided by the use of combining multiple imaging techniques, and the treatment depends both on the lesion-specific risk of complications and on the potential association of some lesions with cardiomyopathy.

Keywords: cardiac aneurysms; cardiac crypts; cardiac diverticula; cardiac recesses; multimodality imaging.

Figure 1

Flow chart of review.

Figure 2

Diagnostic algorithm outpouchings/invaginations.

Figure 3

In all figures red arrows indicate the lesion. (A): left ventricular apical diverticulum, 2D-Multimodality imaging of outpouchings/invaginations. Echocardiography in apical four chambers view; (B): left ventricular apical diverticulum, cardiac contrast-enhanced computer tomography (CCT); (C): left ventricular congenital septal aneurysm in left ventricular non-compaction (LVNC), 2D-echocardiography in parasternal long axis (PLAX) view; (D): left ventricular congenital septal aneurysm, cardiac magnetic resonance (CMR); (E): inferior basal myocardial crypt; 2D-echocardiography in apical two chambers view; (F): myocardial crypt of the mid antero-septal wall in hypertrophic phenotype of basal septum, CMR; (G): multiple myocardial recesses in (LVNC), 2D-echocardiography in apical parasternal long axis (APLAX) view; (H): myocardial recess in left ventricular non-compaction (LVNC), CMR.

Figure 4

Key elements for differential diagnosis of ventricular outpouchings and invaginations. Echo: echocardiography; CT: computer tomography; CMR: cardiac magnetic resonance; LGE: late gadolinium enhancement.