Table 1.

Cardiac MRI features differentiating myxoma from thrombus

Features	Myxoma	Thrombus
Location	Left atrium commonly at fossa ovalis	Left atrium commonly at left atrial appendage or left ventricle in association with infarct
Attachment	Narrow often pedunculated	Broad based
Mobility	Very mobile	Less mobile
Functional impact	Prolapse of lesion through atrioventricular valve	Left ventricular functional impairment common; prolapse through valve not evident
T1 signal	Heterogeneous intermediate T1 signal	Homogeneous hypointense T1 signala
T2 signal	Heterogeneous hyperintense T2 signal	Homogeneous hypointense T2 signala
Gadolinium enhancement	Heterogeneous pattern of enhancement common	Enhancement extremely uncommon unless very organized with high level of fibrous tissue
Inversion time on late gadolinium sequences	200–300 ms	550–650 ms

^aThrombus signal return is dependent on whether the thrombus is acute, subacute or chronic. Signal characteristics described in the table are those demonstrated by chronic thrombus.