Impairment factors for evaluating the patency of drug-eluting stents and bare metal stents in coronary arteries by 64-slice computed tomography versus conventional coronary angiography.

PURPOSE: To identify, using logistic regression models, factors impairing evaluation of patency of drug-eluting stents (DES) and bare metal stents (BMS) in coronary arteries by 64-slice MSCT versus conventional coronary angiography (CAG). MATERIALS AND METHODS: We evaluated 75 stents (16 DES and 59 BMS; 57 in males) implanted in 49 consecutive subjects (35 males; aged 68+/-10 years) by enhanced ECG-gated MSCT (Light Speed VCT, General Electrics) and CAG. Stents were classified by implantation site: (1) right coronary artery, (2) left anterior descending branch (LAD), and (3) left circumflex branch. Logistic regression models were used to predict agreement of findings between CT and CAG and impossibility of evaluating stent patency by CT, using age, sex, body mass index (BMI), heart rate, stent type, stent size, diabetes mellitus, and hypertension. RESULTS: By CAG, patency was confirmed in 15 DES (94%) and 54 BMS (91%); significant in-stent restenosis of >/=50% was observed in 1 DES (6%) and 4 BMS (7%), and total occlusion in 1 BMS (2%). By CT, patency was confirmed in 69% DES and 78% BMS; 5 BMS (8%) revealed a low CT area inside the stent with significant in-stent restenosis, and 2 BMS (3%) revealed total occlusion. Patency of 31% DES and 22% BMS was unconfirmed by CT. Agreement of findings between CT and CAG was observed in 69% DES and 80% BMS. Significant negative predictors of agreement of findings between CT and CAG were, by category: (1) BMI (relative risks, 0.77; 95% confidence intervals [95% CI], 0.62-0.97); (2) site of implantation in LAD only (positive predictor) and BMI (relative risks, 4.59 and 0.77; 95% CI, 1.02-20.6 and 0.61-0.97, respectively); (3) BMI (relative risks, 0.77; 95% CI, 0.62-0.97). Significant predictors of impossibility of evaluating stent patency by CT were, by category: (1) BMI (relative risks, 1.54; 95% CI, 1.01-2.36); (2) none; (3) BMI (relative risk, 1.65; 95% CI, 1.03-2.63). Stent type and size were not significant predictors in any category. The percentage agreement of findings between CT and CAG was significantly higher in subjects with BMI<22 kg/m(2) than in those with 22 kg/m(2)

Quantitative 4-dimensional volumetric analysis of left ventricle in ischemic heart disease by 64-slice computed tomography: a comparative study with invasive left ventriculogram.

OBJECTIVE: To elucidate the usefulness of CT in evaluating left ventricular (LV) volumes and ejection fraction (EF) in ischemic heart disease (IHD), we compared 64-slice CT with conventional left ventriculography (CLVG). MATERIALS AND METHODS: 71 subjects with suspected or confirmed IHD underwent ECG-gated enhanced CT before or after cardiac catheterization. End-diastolic volume (EDV) and end-systolic volume (ESV) of LV were selected in 20 phases of R-R interval of ECG, and data sets were reconstructed to determine EDV, ESV, SV, and EF of LV using a multislice area summation method; in CLVG these parameters were calculated from the right anterior oblique 30-degree projection. RESULTS: Correlation coefficients between CT and CLVG for EDV, ESV, SV, and EF were 0.759, 0.895, 0.550, and 0.836, respectively (P<0.01). In 35 subjects without apical asynergy of LV wall motion, correlation coefficients between CT and CLVG were 0.77, 0.91, 0.63, and 0.87 respectively (P<0.01); in 36 subjects, with apical asynergy, the correlation coefficients were 0.751, 0.875, 0.503, and 0.738, respectively (P<0.01). The limits of agreement of all parameters were wider in the subjects with apical asynergy of LV wall motion than the subjects without. CONCLUSION: There was good correlation between EDV, ESV, SV, and EF estimated by CT and those by CLVG, but CT tended to overestimate EDV and ESV and underestimate EF. In subjects with apical asynergy of LV wall motion, estimates of EF were less correlated between CT and CLVG and the limits of agreement of all parameters were wider than in those without. These discrepancies may come from the capability of CT to estimate LV wall asynergy 3-dimensionally and more accurately.

Utility of multislice computed tomography with a 64-data acquisition system for four-dimensional volumetric analysis using a pulsating phantom and considering pulsation rate and reconstruction methods.

PURPOSE: To evaluate 64-data acquisition system (DAS) MSCT (Light Speed VCT, GE) at 0.625 mm slice thickness, 0.35 s/rotation, tube 120 kV at 400 mA, ECG-gated for 4-D volumetric analysis, we used pulsating phantoms to measure end-diastolic (EDV) and end-systolic (ESV) volume and ejection fraction (EF) to assess reconstruction methods especially for higher pulsation rates. MATERIALS AND METHODS: A pulsating device (AZ-631N, Anzai Medical) with contrast material (300 mgI/dl) diluted 10x with saline was moved at 40-110 to-and-fro movements/min. ECG-gated MSCT was performed x5 per pulsation rate. The EDV and ESV were measured using workstation (Virtual Place Advance Plus, Aze). RESULTS: The mean EDV and ESV were 98, 97, 97 96, 95, 94, and 101% and 145, 143, 142, 144, 145, 149, 156 and 160%, respectively, compared to the static state. EF was 80, 81, 81, 80, 79, 77, 73, and 76% at 40-110 pulsations/min, when reconstructed by the segmented method, but was improved to 82, 83, 85, and 84% at 80-110 beat/min when reconstructed by the burst method. The latter is therefore more appropriate for higher rates. CONCLUSION: This 64-DAS MSCT can measure EDV even at high beat rates (up to 110 beats per minute) compared to the static state. Because ESV tended to be overestimated by approximately 140-160% compared with the static state, EF tended to be underestimated by approximately 73-81% compared with the static state. However, at higher beat rates of >70 beat/min, an appropriate reconstruction method (the burst method) may further improve the accuracy of EF measurement.

New acquisition method to exclusively enhance the left side of the heart by a small amount of contrast material achieved by multislice computed tomography with 64 data acquisition system.

PURPOSE: To exclusively enhance the left side of the heart by a small amount of contrast material (CM) using rapid acquisition of multislice computed tomography (MSCT) with a 64-data acquisition system (DAS). MATERIALS AND METHODS: Forty consecutive subjects underwent MSCT (Light Speed VCT, GE) with 0.625mm slice thickness to evaluate coronary arteries. We first measured transit time, using 8ml of CM followed by 20ml saline. Dependent upon transit time, total volume of CM was determined, ranging from 45 to 63ml. After injection of CM at a rate of 4ml/s, followed by 47ml saline at 3.5ml/s, ECG-gated MSCT scanning was performed. The mean and standard deviation (S.D.) of CT values of the right atrium (RA), right ventricle (RV), left atrium (LA), left ventricle (LV), ascending aorta (Ao) and each coronary artery were measured. RESULTS: The mean of the CT values of the RA, RV, LA, LV, Ao, right coronary artery, left main, left anterior descending branch, and left circumflex branch were 225+/-76, 251+/-72, 353+/-55, 355+/-51, 352+/-34, 312+/-65, 296+/-57, 285+/-55, and 267+/-60HU, respectively. The corresponding S.D.s of the CT values were 39+/-22, 37+/-16, 32+/-7, 31+/-8HU, 25+/-5, 36+/-15, 31+/-13, 36+/-23, and 40+/-18HU, respectively. The mean of CT values of the RA and RV were significantly lower than those of the LA, LV, Ao, and each coronary artery (P<0.01), with excellent S.D.s. We could easily obtain three-dimensional coronary arterial and LV images without artifact of the RA and RV. CONCLUSIONS: Using 64-DAS MSCT, we successfully obtained exclusive enhancement of the left side of the heart using a small amount of CM.