Yoshiaki Shintani

Characterization of Hyperintense Plaque With Noncontrast T1-Weighted Cardiac Magnetic Resonance Coronary Plaque Imaging: Comparison With Multislice Computed Tomography and Intravascular Ultrasound

OBJECTIVES This study sought to characterize coronary hyperintense plaques (HIP) using noncontrast T(1)-weighted imaging (T1WI) in cardiac magnetic resonance, which was then compared with multislice computed tomography and intravascular ultrasound. BACKGROUND Carotid plaque components such as intraplaque hemorrhages and/or lipid-rich necrotic cores can be detected as HIP by noncontrast T1WI. Although coronary HIPs have been successfully detected using this technique, the properties of hyperintense signals in coronary plaques have not yet been systematically evaluated. METHODS Thirty-eight lesions from 37 patients with angina pectoris who demonstrated >70% coronary stenosis on multislice computed tomography were evaluated by noncontrast T1WI using a 1.5-T magnetic resonance imager, and 25 lesions were evaluated by intravascular ultrasound. Signal intensity of coronary plaque to cardiac muscle ratio >1.0 was defined as HIP. We divided 25 lesions into the 2 groups, according to the presence or absence of HIP: HIP (n = 18) and non-HIP (n = 7) groups. RESULTS In comparison with the non-HIP group, the HIP group demonstrated significantly higher coronary plaque to cardiac muscle ratio (1.7 +/- 0.7 vs. 0.9 +/- 0.1, p < 0.01), higher frequency of positive remodeling as observed by both multislice computed tomography (89% vs. 0%, p<0.0001) and intravascular ultrasound (94% vs. 14%, p < 0.001) and ultrasound attenuation (100% vs. 14.3%, p < 0.0001). The frequency of spotty calcification tended to be higher in HIP (89% vs. 50%, p = 0.079). The HIP group also exhibited a significantly lower computed tomography density (-23.2 +/- 20.7 Hounsfield units [HU] vs. 9.6 +/- 20.5 HU, p < 0.01). In addition, the incidence of transient slow-flow phenomena was significantly higher in the HIP group than in the non-HIP group (83% vs. 14%, p < 0.01). CONCLUSIONS The typical HIP case was associated with ultrasound attenuation, positive remodeling, remarkably low computed tomography density, and a high incidence of slow-flow phenomena. Noncontrast T1WI in cardiac magnetic resonance imaging may be useful for the assessment of coronary plaque characterization in patients with coronary artery disease.

The bifurcation study using 64 multislice computed tomography.

Background: Various two‐stent techniques have been applied to aggressively treat bifurcation lesions as the introduction of drug‐eluting stents (DES) and the importance of the bifurcation angle and three‐dimensional (3D) structure has come to be recognized. Recent 64 multislice computed tomography (MSCT) technology provides accurate information about the 3D bifurcation geometry of the coronary arteries and with reproducibility. Objectives: The purpose of this study is to disclose the coronary bifurcation angle and 3D structure in humans and elucidate the importance of bifurcation angle for the crush technique using MSCT. Methods: Two hundred and nine patients who were suspected to have angina pectoris and underwent CT angiography using MSCT were examined. The 3D‐volume rendering (VR) image was reconstructed by two technicians and was used for the assessment of each coronary bifurcation angles. Results: The average LMT bifurcation angles (∠LMT‐LAD, ∠LMT‐LCx, ∠LAD‐LCx) were 143 ± 13°, 121 ± 21°, and 72 ± 22°, respectively, the average ∠LAD‐D was 138 ± 19°, the average ∠LCx‐OM was 134 ± 23°, the average distal RCA bifurcation angles (∠RCA‐4AV, ∠RCA‐4PD, ∠4AV‐4PD) were 152 ± 15°, 137 ± 20°, and 61 ± 21°, respectively. In addition, a percentage of steep angled bifurcation (<110°) was significantly higher in the LMT (26%) than in other bifurcations (P < 0.05). Conclusions: LMT bifurcation has been shown to have a higher rate of steep angled bifurcation in humans, it is therefore necessary to take the bifurcation angle into consideration in the case of LMT stenting. These data suggest that a bifurcation study using MSCT can clarify the 3D structure of coronary bifurcation and may provide useful information for bifurcation stenting.

Impact of a prolonged delivery inflation time for optimal drug-eluting stent expansion†

Purpose: We examined the importance of prolonged inflation time for optimal sirolimus‐eluting stent (SES) or paclitaxel‐eluting stent (PES) expansion. Methods: Eighty‐one de novo lesions deployed single SES or PES between April 2007 and March 2008 were divided into four groups; group 1: 21 SES deployed at 20 atm × 60 sec, group 2: 20 SES deployed with 2‐step inflation at 20 atm × 60 sec following 20 atm × 20 sec, group 3: 20 PES deployed same as group 1, group 4: 20 PES deployed same as group 2. The minimal lumen diameter (MLD) and stent expansion ratio (SER; stent cross‐ sectional area at lesion/balloon cross‐sectional area which was calculated according to the compliance chart at the same atmosphere as stent deployment) were compared between group 1 and group 2 in SES, between group 3 and group 4 in PES. Results: The MLD of post 60 sec was significantly higher than that of post 20sec (2.84 ± 0.28 mm in group 1, 2.76 ± 0.33 mm in group 2 vs. 2.54 ± 0.33 mm in group 2; P = 0.003, 0.045, respectively and 2.94 ± 0.28 mm in group 3, 3.00 ± 0.34 mm in group 4 vs. 2.69 ± 0.35 mm in group 4; P = 0.022, 0.007, respectively). The SER of post 60 sec was significantly higher than that of post 20 sec (79.3% ± 8.5% in group 1, 80.8% ± 7.8% in group 2 vs. 71.1% ± 10.2% in group 2; P = 0.014, 0.011, respectively and 81.1% ± 7.9% in group 3, 84.3% ± 9.9% in group 4 vs. 72.6% ± 10.5% in group 4, P = 0.011, 0.001, respectively). Conclusion: The prolonged delivery inflation for 60 sec may result in a more optimal stent expansion. It is therefore considered to be a useful method for deploying drug‐eluting stent.