Quantitative assessment of in-stent dimensions: a comparison of 64 and 16 detector multislice computed tomography to intravascular ultrasound.
OBJECTIVE
To determine the utility of multislice computed tomography (MSCT) technology to evaluate coronary stent luminal diameter.


BACKGROUND
Stent metal induced "blooming" artifact makes quantitative coronary angiography by MSCT difficult. There is a paucity of data on the efficacy of using 64 and 16 detector MSCT in evaluating coronary stents.


METHODS
We evaluated four commercially available bare metal and polymer coated drug eluting stents using 64 and 16 detector MSCT for the following: (1) Strut density in Hounsfield's Units (Hu) using a 2 mm MIP; (2) In-stent luminal diameter (ISLD) measured by MSCT compared to intravascular ultrasound (IVUS).


RESULTS
Increased strut thickness did not correlate with greater strut density as measured in Hu (R(2) = 0.05, P = 0.29). The ISLD by 16 MSCT vs. IVUS is: Vision 1.63 +/- 0.58 mm vs. 2.8 +/- 0.0; Cypher 1.80 +/- 0.00 vs. 2.9 +/- 0.0; Taxus 1.87 +/- 0.58 vs. 2.9 +/- 0.0; Liberté 1.80 +/- 0.10 vs. 3.0 +/- 0.1 (P < 0.01). ISLD determined by 64 MSCT vs. IVUS is: Vision 1.73 +/- 0.06 mm vs. 2.8 +/- 0.0; Cypher 1.87 +/- 0.12 vs. 2.9 +/- 0.0; Taxus 1.77 +/- 0.06 vs. 2.9 +/- 0.0; Liberté 1.80 +/- 0.10 vs. 3.0 +/- 0.1 (P < 0.01).


CONCLUSIONS
When compared to IVUS measurements, MSCT results in a significant, underestimation of ISLD. This consistent underestimation (even with 64 MSCT) limits the applicability of CT angiography to quantify in-stent restenosis.
Beohar
Nirat
N
Division of Cardiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA. cdavidso@nmh.org
Robbins
Joel D
JD
Cavanaugh
Brendan J
BJ
Ansari
Asimul H
AH
Yaghmai
Vahid
V
Carr
James
J
Davidson
Charles J
CJ
D016477:Artifacts; D017023:Coronary Angiography / Q000379:methods; D023903:Coronary Restenosis / Q000000981:diagnostic imaging; D006801:Humans; D010865:Pilot Projects; D011474:Prosthesis Design; D015203:Reproducibility of Results; D015607:Stents; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*; D018084:Ultrasonography, Interventional