The coronary lumen area just after percutaneous transluminal coronary
angioplasty (PTCA) was assessed by intravascular ultrasonography (IVUS
) with 4.3F cardiovascular imaging systems (CVIS) and quantitative cor
onary angiography (QCA) with Kontron CARDIO 500. Altogether 34 lesions
were divided into two groups by IVUS findings using Nissen's circular
shape factor (CSF), which was defined by the (calculated perimeter/ob
served perimeter)(2), expressing lumen eccentricity. The eccentric gro
up (CSF less than or equal to 0.92) was 22, and concentric group (CSF
> 0.92) was 12. The minimum lumen diameter by IVUS and QCA (both edge-
detection and densitometric methods) correlated in both the eccentric
and concentric groups. As for the lumen area, only the QCA densitometr
ic method in the concentric group correlated with the lumen area deter
mined by IVUS. Despite using QCA, it is almost impossible for angiogra
phy to determine the lumen area just after PTCA if an eccentric lesion
with a tear or dissection had occurred.