One-stop shop assessment for atrial septal defect closure using 256-slice coronary CT angiography.

OBJECTIVES: To investigate the feasibility and accuracy of measurement of the pulmonary to systemic blood flow ratio (Qp/Qs) and defect and rim sizes in secundum atrial septal defects (ASDs) using 256-slice CT, compared to the reference transoesophageal echocardiography (TEE) and right heart catheterization (RHC) measurements. METHODS: Twenty-three consecutive adult patients with secundum ASDs who underwent retrospective ECG-gated coronary CT angiography (CCTA), TEE and RHC were enrolled in this study. Right ventricular (RV) and left ventricular (LV) stroke volumes (SV) were calculated by biventricular volumetry of CCTA. Qp/Qs-CT was defined as RVSV/LVSV. The sizes of the defect and rim were measured by multi-planar reconstruction CT images. Correlations between Qp/Qs-CT and Qp/Qs-RHC and between the defect diameter obtained by CT and TEE were analyzed by Pearson's coefficient analysis. Rim sizes by CT and TEE were compared by paired t-test. RESULTS: Qp/Qs-CT was significantly correlated with Qp/Qs-RHC (r = 0.83, p < 0.0001), and the defect diameter by CT was significantly correlated with that by TEE (r = 0.95, p < 0.0001). There was no significant difference between CT and TEE in measurements of rim size. CONCLUSIONS: 256-slice CCTA allows measuring Qp/Qs and size of defects and rims in patients with secundum ASDs, accomplishing pretreatment evaluation non-invasively and comprehensively. KEY POINTS: • Quantification of left-to-right shunting can be performed reliably and accurately by CT. • The sizes of defects and rims can be measured accurately using 256-slice CT. • 256-slice CT permits pretreatment evaluation of ASD non-invasively and comprehensively.

Clinical impact of left ventricular eccentricity index using cardiac MRI in assessment of right ventricular hemodynamics and myocardial fibrosis in congenital heart disease.

OBJECTIVES: To investigate the utility of eccentricity index (EI) using cardiac cine MRI for the assessment of right ventricular (RV) hemodynamics in congenital heart disease (CHD). METHODS: Fifty-five patients with CHD (32 women; mean age, 40.7 ± 20.9 years) underwent both cardiac MRI and right heart catheterization. EI was defined as the ratio of the distance between the anterior-posterior wall and the septal-lateral wall measured in the short-axis of mid-ventricular cine MRI. Correlations between EIs and RV hemodynamic parameters were analyzed. EIs were compared between patients with and without late gadolinium enhancement (LGE). RESULTS: A strong correlation between mean pulmonary artery pressure (PAP) and systolic EI (r = 0.81, p < 0.0001) and a moderate negative correlation between diastolic EI and RV ejection fraction (EF) (r = -0.62, p < 0.0001) were observed. Receiver operating characteristic analysis revealed optimal EI thresholds for detecting patients with mean PAP ≥40 mmHg with C-statistics of 0.90 and patients with RVEF <40 % with C-statistics of 0.78. Systolic EIs were significantly greater for patients with LGE (1.45 ± 0.05) than for those without LGE (1.15 ± 0.07; p < 0.001). CONCLUSIONS: EI offers a simple, comprehensive index that can predict pulmonary hypertension and RV dysfunction in CHD. KEY POINTS: • EI offers a simple and comprehensive index of RV hemodynamics. • EI could predict pulmonary hypertension and RV dysfunction. • Left ventricular deformation expressed as high EI is related to myocardial fibrosis.

Quantitative assessment of right ventricular function and pulmonary regurgitation in surgically repaired tetralogy of Fallot using 256-slice CT: comparison with 3-Tesla MRI.

OBJECTIVES: To compare 256-slice cardiac computed tomography (CCT) with cardiac magnetic resonance (CMR) imaging to assess right ventricular (RV) function and pulmonary regurgitant fraction (PRF) in patients with repaired tetralogy of Fallot (TOF). METHODS: Thirty-three consecutive patients with repaired TOF underwent retrospective ECG-gated CCT and 3-Tesla CMR. RV and left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF) were measured using CCT and CMR. PRF-CCT (%) was defined as (RVSV - LVSV)/RVSV. PRF-CMR (%) was measured by the phase-contrast method. Repeated measurements were performed to determine intra- and interobserver variability. RESULTS: CCT measurements, including PRF, correlated highly with the CMR reference (r = 0.71-0.96). CCT overestimated RVEDV (mean difference, 17.1 ± 2.9 ml), RVESV (12.9 ± 2.1 ml) and RVSV (4.2 ± 2.0 ml), and underestimated RVEF (-2.6 ± 1.0%) and PRF (-9.1 ± 2.0%) compared with CMR. The limits of agreement between CCT and CMR were in a good range for all measurements. The variability in CCT measurements was lower than those in CMR. The estimated effective radiation dose was 7.6 ± 2.6 mSv. CONCLUSIONS: 256-slice CCT can assess RV function and PRF with relatively low dose radiation exposure in patients with repaired TOF, but overestimates RV volume and underestimates PRF. KEY POINTS: 256-slice CT assessment of RV function is highly reproducible in repaired TOF. Pulmonary regurgitation can be evaluated by biventricular systolic volume difference. CT overestimates RV volume and underestimates pulmonary regurgitation, compared with MRI.

Quantification of lung perfusion blood volume with dual-energy CT: assessment of the severity of acute pulmonary thromboembolism.

OBJECTIVE: The purpose of this study was to evaluate the usefulness of quantification of lung perfused blood volume (PBV) with dual-energy CT (DECT) for assessment of the severity of acute pulmonary thromboembolism (PTE). MATERIALS AND METHODS: We retrospectively analyzed the records of 72 patients with PTE and 168 without PTE who underwent DECT. The PTE patients were divided into high-, intermediate-, and low-risk groups based on clinical symptoms and right ventricular dysfunction. Correlations between quantification of whole-lung PBV and clinical severity were evaluated. Also evaluated was the relation between quantification of whole-lung PBV and right-to-left ventricular diameter ratio on CT images, which was used as an indicator of right ventricular dysfunction. RESULTS: In the PTE and control groups, the whole-lung PBVs were 27.6 ± 7.9 and 29.9 ± 6.8 HU with a significant difference between them (p < 0.0281). In the high-, intermediate-, and low-risk PTE groups, the whole-lung PBVs were 16.0 ± 2.9, 21.0 ± 4.2, and 31.4 ± 5.8 HU with a significant difference between them (p < 0.05). There was no significant difference in whole-lung PBV between the control group and the low-risk PTE group, but there was a significant difference between the control group and the other two PTE groups. In PTE patients, whole-lung PBV had negative correlation with right-to-left ventricular diameter ratio (R = -0.567, p < 0.001). CONCLUSION: Quantification of lung PBV with DECT is useful for assessment of the clinical severity of PTE and can be used as an indicator of right ventricular dysfunction.

Comparison of outcome in aortic dissection with single false lumen versus multiple false lumens: CT assessment.

PURPOSE: To investigate the clinical features and outcomes of type B multibarreled (multiple false lumens) aortic dissection (AD) compared with those of double-barreled (single false lumen) AD by using computed tomography (CT). MATERIALS AND METHODS: The ethics committee approved this study. Informed consent was waived. A total of 221 consecutive patients (127 men; median age, 62 years) with acute type B AD were evaluated by using CT. The clinical outcome, including AD-related events, AD-related deaths, and long-term survival, was retrospectively reviewed and compared with that of patients with double-barreled AD during the follow-up period (median, 60 months). Survival analysis was performed by using Kaplan-Meier analysis with the log-rank test within 10 years after onset. The Cox proportional hazards model was used to estimate the risk for AD-related events and death. RESULTS: In 201 of 221 patients (91.0%), double-barreled AD was identified at initial CT. In 20 of 221 patients (9%), multibarreled AD was identified at initial CT (n = 16) and follow-up CT (n = 4). In 15 of 20 patients (75%) with multibarreled AD, AD-related events occurred, and nine patients (45%) died of AD-related complications. Patients with multibarreled AD showed significantly poorer survival rates than patients with double-barreled AD (P = .0002). The presence of a multibarreled false lumen was the most powerful risk factor for AD-related deaths according to multivariate analysis (hazard ratio, 5.61; 95% confidence interval: 2.44, 12.90; P < .0001). CONCLUSION: Multibarreled AD occurs in 9% of acute type B dissections. The presence of multibarreled AD is a powerful predictor of AD-related deaths.