Careful tracing to identify its attachment to the orifice of IVC makes a differential diagnosis.
Chiari network has little clinical significance, but it might cause trouble during percutaneous procedures.
cases of entrapment of right-heart catheters, or entanglement and herniation into the LA by atrial septal defect occluding device have been reported.
F3: A: Chiari network (arrowheads) is the delicate freely mobile membranous structure in the RA. B: RV inflow view shows its close relationship with IVC. IVC: inferior vena cava, LA: left atrium, LV: left ventricle, RA: right atrium, RV: right ventricle.
Echo findings s/o prominent crista terminalis instead of tumor are as follows: a nodular mass of similar echogenicity with adjacent myocardium;
the location on the posterolateral wall of RA near the SVC, which corresponds to the course of crista terminalis connecting the SVC and IVC;
the phasic change in size becomes thicker or larger during atrial systole.
. Bicaval view of TEE best visualizes the crista terminalis.
Christa terminalis. Normal appearance (arrow) in the RA in a TTE apical four-chamber view (left) and a TEE view (right). Crista Terminalis ■ Crista terminalis is a well-defined fibromuscular ridge separating a smooth sinus venarum and trabeculated RA. ■ Externally, it corresponds to the sulcus terminalis, and internally, it extends from SVC to IVC along the lateral RA wall. Embryologically, crista terminalis develops from the septum spurium, which corresponds to the fused boundary between embryonic sinus venosus and RA proper. Prominent crista terminalis may be confused for RA tumor on TTE.
Crista terminalis (arrowhead) appears as the mass arising from the posterior wall of RA in the four-chamber view (A), but it is well visualized as a muscular ridge near SVC in transesophageal echocardiography (B). EV: Eustachian valve, IVC: inferior vena cava, LA: left atrium, LV: left ventricle, RA: right atrium, RV: right ventricle, SVC: superior vena cava
