Central aortic valve coaptation area during diastole as seen by 64-multidetector computed tomography (MDCT)

As multiple new procedures now require better visualization of the aortic valve, we sought to better define the central aortic valve coaptation area seen during diastole on multi-detector row cardiac computed tomography (MDCT). 64-MDCT images of 384 symptomatic consecutive patients referred for coronary artery disease evaluation were included in the study. Planimetric measurements of this area were performed on cross-sectional views of the aortic valve at 75% phase of the cardiac cycle. Planimetric measurement of central regurgitation orifice area (ROA) seen in patients with aortic regurgitation and Hounsfield units of the central aortic valve coaptation area were performed. Mean area of the central aortic valve coaptation area was 5.34 ± 5.19 mm2 and Hounsfield units in this area were 123.69 ± 31.31 HU. The aortic valve coaptation area (mm2) measurement in patients without AR was: 4.90 ± 0.17 and in patients with AR: 10.53 ± 0.26 (P = <0.05). On Bland–Altman analysis a very good correlation between central aortic valve coaptation area and central ROA was found (r = 0.80, P = <0.001). Central aortic valve coaptation area is a central area present at the coaptation of nodules of arantius of aortic cusps during diastole; it is incompetent and increased in size in patients with aortic regurgitation

Delayed enhancement imaging of myocardial viability: low-dose high-pitch CT versus MRI

Objectives: To evaluate the accuracy of high-pitch delayed enhancement (DE) CT for the assessment of myocardial viability with MRI as the reference standard. Methods: Twenty-four patients (mean age 66.9 ± 9.2years) with coronary artery disease underwent DE imaging with 128-slice dual-source CT (prospective electrocardiography (ECG)-triggering) and MRI at 1.5T. Two observers assessed DE transmurality per segment, and measured signal intensity (MRI) or attenuation (CT) in infarcted and healthy myocardium and noise in the left ventricular blood pool for calculating contrast-to-noise ratios (CNR). Results: 75/408 (18.4%) segments in 18/24 patients (75.0%) showed DE in MRI, of which 28 segments in 10/24 (41.7%) patients were non-viable (scar tissue transmurality >50%). Sensitivity, specificity and accuracy of CT for diagnosis of non-viability were 60.7%, 96.8% and 94.4% per segment, and 90.0%, 92.9% and 91.7% per patient. CNR was significantly higher in MR (7.4 ± 3.0 vs. 4.6 ± 1.5; p = 0.018), and image noise significantly lower (11.6 ± 5.7 vs.15.0 ± 4.5; p = 0.019). Radiation dose of DECT was 0.89 ± 0.07mSv. Conclusions: CTDE imaging in the high-pitch mode enables myocardial viability assessment at a low radiation dose and good accuracy compared with MR, although associated with a lower CNR and higher nois

Relative amplitude index: A new tool for hemodynamic evaluation of periprosthetic regurgitation after transcatheter valve implantation

ObjectiveThe impact of paravalvular aortic regurgitation (PAR) on hemodynamic performance after transcatheter aortic valve implantation (TAVI) remains disputable. Common parameters such as the diastolic blood pressure or the blood pressure amplitude do not provide reproducible results. The aim of our study was to evaluate the impact of PAR on hemodynamics and outcome using the relative amplitude index (RAI).MethodsPAR was prospectively evaluated by echocardiography before discharge in 110 patients. The RAI was calculated according to the formula: RAI = [(Post-TAVI BP amplitude)/(Post-TAVI SBP) − (Pre-TAVI BP amplitude)/(Pre-TAVI SBP)] × 100%, where BP is blood pressure and SBP is systolic blood pressure. Correlations of increased RAI with perioperative outcome were investigated and factors influencing mortality were isolated.ResultsThe incidence of moderate and severe PAR after TAVI was 9% and 1%, respectively. Diastolic pressure or post-TAVI amplitude did not correlate to perioperative outcome. RAI increased from 2 when PAR was <2+ to 7 when PAR was ≥2+ (P = .006). A cut-off value of RAI ≥14 was associated with increased perioperative mortality (29 vs 5%; P = .013) and acute renal injury requiring dialysis (71 vs 18%; P = .001). RAI ≥14 was also associated with higher follow-up mortality at 1 year (57 vs 16%; P = .007). RAI ≥14 (odds ratio [OR], 3.390; 95% confidence interval [CI], 1.6-7.194; P = .00146), PAR ≥2+ (OR, 4.717; 95% CI, 1.828-12.195; P = .00135), and perioperative renal replacement therapy (OR, 12.820; 95% CI, 5.181-31.250; P = .00031) were found to be independent predictors of mortality at 1 year.ConclusionsThe RAI is a useful tool to predict perioperative and 1-year outcome in patients with PAR after TAVI

Dual-step prospective ECG-triggered 128-slice dual-source CT for evaluation of coronary arteries and cardiac function without heart rate control: a technical note

Purpose: To describe prospective ECG-triggered dual-source CT dual-step pulsing (pECGdual_step) for evaluation of coronary arteries and cardiac function. Methods: Fifty-one consecutive patients pre- or post-cardiovascular surgery were examined with adaptive sequential tube current modulated (pECGdual-step) 128-slice dual-source CT without heart rate control (main padding window: 40% RR interval >65bpm/70% RR interval <65bpm). Image quality of coronary arteries was graded (4-point scale), and cardiac function was evaluated. Results: Mean HR was 68bpm. Thirty-seven patients were in stable sinus rhythm (SR); 14 had arrhythmia. Image quality of coronary arteries was diagnostic in 804/816 (98%) of segments. The number of non-diagnostic segments was higher in patients with arrhythmia as compared to those in SR (4% vs. 0.5%; p = 0.01), and there were fewer segments with excellent image quality (79% vs. 94%; p < 0.001) and more segments with impaired image quality (p < 0.001 and p = 0.002). Global and regional LV function could be evaluated in 41 (80%) and 47 (92%) patients, and valvular function in 48 (94%). In 11/14 of patients with arrhythmia, the second step switched to full mAs, increasing radiation exposure to 8.6mAs (p < 0.001). The average radiation dose was 3.8mSv (range, 1.7-7.9) in patients in SR. Conclusion: pECGdual-step128-slice DSCT is feasible for the evaluation of coronary arteries and cardiac function without heart rate control in patients in stable sinus rhythm at a low radiation dos

High-pitch dual-source CT coronary angiography: systolic data acquisition at high heart rates

Objective: To assess the effect of systolic data acquisition for electrocardiography (ECG)-triggered high-pitch computed tomography (CT) on motion artefacts of coronary arteries in patients with high heart rates (HRs). Methods: Eighty consecutive patients (15 women, age 67 ± 14years) with HR ≥70bpm underwent CT angiography of the thoracic aorta (CTA) on 128-slice dual-source CT in ECG-triggered high-pitch acquisition mode (pitch = 3.2) set at 60% (group A, n = 40) or 30% (group B, n = 40) of the RR interval. Two blinded readers graded coronary artery image quality on a three-point scale. Radiation doses were calculated. Results: Inter-observer agreement in grading image quality of the 1,154 coronary segments was good (κ = 0.62). HRs were similar in groups A and B (85 ± 13bpm vs 85 ± 14bpm, p not significant). Significantly fewer coronary segments with non-diagnostic image quality occurred (i.e. score 3) in group B than in group A [2.8% (16/579) vs 8.3% (48/575), p < 0.001]. Seventeen patients (42.5%) of group A and 12 patients (30.0%) of group B had at least one non-diagnostic segment. Effective radiation doses were 2.3 ± 0.3mSv for chest CTA. Conclusion: A systolic acquisition window for high-pitch dual-source CTA in patients with high HRs (≥70bpm) significantly improves coronary artery image quality at a low radiation dos

High-pitch dual-source CT angiography of the aortic valve-aortic root complex without ECG-synchronization

Purpose: To compare image quality and radiation dose of high-pitch computed tomography angiography(CTA) of the aortic valve-aortic root complex with and without prospective ECG-gating compared to a retrospectively ECG-gated standard-pitch acquisition. Materials and Methods: 120 patients(mean age 68 ± 13years) were examined using a 128-slice dual-source CT system using prospectively ECG-gated high-pitch(group A; n = 40), non-ECG-gated high-pitch(group B; n = 40) or retrospectively ECG-gated standard-pitch(C; n = 40) acquisition techniques. Image quality of the aortic root, valve and ascending aorta including the coronary ostia was assessed by two independent readers. Image noise was measured, radiation dose estimates were calculated. Results: Interobserver agreement was good(κ = 0.64-0.78). Image quality was diagnostic in 38/40 patients(group A), 37/40(B) and 38/40(C) with no significant difference in number of patients with diagnostic image quality among all groups (p = 0.56). Significantly more patients showed excellent image quality in group A compared to groups B and C(each, p < 0.01). Average image noise was significantly different between all groups(p < 0.05). Mean radiation dose estimates in groups A and B(each; 2.4 ± 0.3mSv) were significantly lower compared to group C(17.5 ± 4.4mSv; p < 0.01). Conclusion: High-pitch dual-source CTA provides diagnostic image quality of the aortic valve-aortic root complex even without ECG-gating at 86% less radiation dose when compared to a standard-pitch ECG-gated acquisitio

Diagnostic accuracy of high-pitch dual-source CT for the assessment of coronary stenoses: first experience

Objectives: The objective was to prospectively investigate the diagnostic accuracy of high-pitch (HP) dual-source computed tomography coronary angiography (CTCA) compared with catheter coronary angiography (CCA) for the diagnosis of significant coronary stenoses. Methods: Thirty-five patients (seven women; mean age 62 ± 8years) underwent both CTCA and CCA. CTCA was performed with a second-generation dual-source CT system permitting data acquisition at an HP of 3.4. Patients with heart rates >60bpm were excluded from study enrolment. All coronary segments were evaluated by two blinded and independent observers with regard to image quality on a four-point scale (1: excellent to 4: non-diagnostic) and for the presence of significant coronary stenoses (defined as diameter narrowing exceeding 50%). CCA served as the standard of reference. Radiation dose values were calculated using the dose-length product. Results: Diagnostic image quality was found in 99% of all segments (455/459). Non-diagnostic image quality occurred in a single patient with a sudden increase in heart rate immediately before and during CTCA. Taking segments with non-evaluative image quality as positive for disease, the sensitivity, specificity and positive and negative predictive values were 94, 96, 80 and 99% per segment and 100, 91, 88 and 100% per patient. The effective radiation dose was on average 0.9 ± 0.1mSv. Conclusion: In patients with heart rates ≤60bpm, CTCA using the HP mode of the dual-source CT system is associated with high diagnostic accuracy for the assessment of coronary artery stenoses at sub-milliSievert dose