CTA Assessment of Saphenous Vein Grafts and Internal Thoracic (Mammary) Arteries

Coronary Bypass Graft Assessment

Coronary bypass grafts, both venous and arterial, are more readily evaluated by CT angiography (CTA) than are coronary arteries, because of:

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  Their large diameter (more so for venous than arterial conduits)

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  Their minimal motion, when compared with coronary arteries, because they are largely extracardiac

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  Their general lack of calcification, versus the common and often extensive calcification of native coronary arteries

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  Simpler courses (but not always) with little overlap. Some exceptions:

  • Posterior transverse sinus course of a venous graft or right internal mammary artery (RIMA) graft to the circumflex

  • Twisted course of vein grafts if multiple and adjacent

  • The presence of jump-grafts (sequential graft insertions; usually saphenous)

  • Internal thoracic artery positioned tightly against the chest wall, in which case the use of bone extraction software when post-processing may eliminate depiction of the internal mammary artery (IMA) graft