Review of D-Shape Left Ventricle Seen on Magnetic Resonance Imaging (MRI) or Computed Tomography (CT), Similar to the Movahed Sign Seen on Cardiac Gated Single-Photon Emission Computed Tomography (SPECT) as an Indicator for Right Ventricular Overload

The "Movahed sign" refers to the presence of a D-shaped left ventricle on cross-sectional cardiac imaging due to interventricular septal flattening seen during cardiac gated single-photon emission computed tomography (SPECT) This phenomenon arises from significant right ventricular (RV) pressure or volume overload, which pushes the septum toward the left ventricle (LV) and distorts the LV's normally circular profile into a "D" shape. However, the prevalence and incidence of similar findings during cardiac Magnetic Resonance Imaging (MRI) or computed tomography (CT) are not known. The goal of this study was to perform a literature search focusing on the "Movahed sign" or D-shaped left ventricle in the context of cardiac MRI and CT. Databases searched included PubMed and Google Scholar, and reference lists of relevant articles were reviewed. The echocardiography literature was also consulted for foundational concepts of septal flattening. Key data on pathophysiology, imaging features, clinical correlations, and prognostic significance were extracted.