Myocardial Perfusion Artifacts Myocardial Perfusion Artifacts Dark Rim Along Endocardial Border From Systolic Motion Reference: Storey, P et al, MRM 48:1028-1036, 2002 Myocardial Perfusion Artifacts Early • Dark rim is exaggerated during systole due to motion • Dark rim is exaggerated during early maximal blush because of increased susceptibility Late Increasing Contrast Washout Time Dark Rim Along Endocardial Border Systole Diastole Increasing Cardiac Phases Myocardial Perfusion Artifacts Dark Rim Artifact in Phase-Encoding Direction Reference: Univ Minn, Jerosh-Herold, M., et al Increasing Contrast Washout Time PE PE Early PE PE PE PE PE PE All images at TT = 255ms, RR ~ 800ms Late •Phase-encoding direction typically has lower resolution than readout direction •Lower resolution leads to stronger Gibbs ringing artifacts •Lower resolution leads to more intravoxel dephasing due to susceptibility Myocardial Perfusion Artifacts Without Rotated FOV, iPAT Artifacts May Cause False Perfusion Defects in Postero-Lateral Wall Without Rotated FOV With Rotated FOV Myocardial Perfusion Artifacts Inadquate RF Spoiling appears as little dancing dark lines in septal and antero-lateral walls To avoid RF Spoiling Artifacts: • Use RF spoiling ON • Use low Flip (10-12 deg) Reference: Crawley, A.P et al, MRM Nov (3) 248-260, 1988 Perfusion Quality Control Is the bolus tight enough? Good Bolus • Strong bloodpool blush • Quick bloodpool washout • Discernable 2nd Pass Bad Bolus: • Leaky IV or low njection rate • High cardiac output • Pulmonary disease • Intracardiac shunt Perfusion Quality Control Is the bolus tight enough? Good Bolus: • Mean Curve ROI in LV • Peaks in 5-10 sec • Recirculation Bad Bolus: • Mean Curve ROI in LV • Peaks in 20-30 sec • No recirculation .. .Myocardial Perfusion Artifacts Dark Rim Along Endocardial Border From Systolic Motion Reference: Storey, P et al, MRM 48:1028-1036, 2002 Myocardial Perfusion Artifacts Early •... Gibbs ringing artifacts •Lower resolution leads to more intravoxel dephasing due to susceptibility Myocardial Perfusion Artifacts Without Rotated FOV, iPAT Artifacts May Cause False Perfusion Defects... Rotated FOV With Rotated FOV Myocardial Perfusion Artifacts Inadquate RF Spoiling appears as little dancing dark lines in septal and antero-lateral walls To avoid RF Spoiling Artifacts: • Use RF spoiling