Synergy of MDCT and Cine MRI for the Evaluation of Cardiac Motility

Is cardiac CT a reproducible alternative for cardiac MR in adult patients with a systemic right ventricle?

OBJECTIVE

20 % of patients with a systemic RV are pacemaker dependent, and unsuitable to undergo cardiac magnetic resonance (CMR). Multidetector row computed tomography (MDCT) could provide a reproducible alternative to CMR in these patients. The aim of this study was to compare variability of MDCT with CMR.

METHODS

Thirty-five patients with systemic RV underwent either MDCT (n = 15) or CMR (n = 20). Systemic RV volumes and ejection fraction were obtained, and intra- and interobserver variability for both modalities were assessed and compared.

RESULTS

We found the intra- and interobserver variability of volumes and function measurements of the systemic RV obtained with MDCT to be higher compared with those obtained with CMR. However, these differences in variability were not significant, the only exception being the interobserver variability of systemic RV stroke volume.

CONCLUSIONS

MDCT provides a reproducible alternative to CMR for volumes and function assessment in patients with a systemic RV.

Estimation of global and regional cardiac function using 64-slice computed tomography: A comparison study with echocardiography, gated-SPECT and cardiovascular magnetic resonance

BACKGROUND

Sixty-four-slice multidetector spiral computed tomography (CT) has improved temporal resolution and reduced acquisition time. We aimed to evaluate the functional analysis using 64-slice CT comparing with echocardiography, electrocardiographically gated single-photon emission tomography (SPECT) and cardiovascular magnetic resonance (CMR).

METHODS

Six-three patients (77.4+/-18.6 bpm) underwent 64-slice CT and CMR (echocardiography in 55; SPECT in 33) within 2 weeks were retrospectively reviewed. The left ventricular volumetric data from different methods were compared with CMR. Regional wall motion was compared between CT and CMR in a 17-segment and 4-point system (1=normal to 4=akinesis/dyskinesis).

RESULTS

Ejection fraction (EF), end-diastolic volume (EDV) and end-systolic volume (ESV) by CT agreed well with CMR (bias+/-SD, -0.22%+/-4.18, r=0.97;-0.59 mL+/-15.21, r=0.98; 1.09 mL+/-10.61, r=0.99) over a wide range of left ventricular (LV) function (EF 18-76% by CMR). Our results also showed good correlation of EF measured by CT and echocardiography (r=0.87) or SPECT (r=0.91, all P<0.0001); however, standard deviation of EF difference between CT and CMR was significantly less than echocardiography or SPECT (P<0.005). For regional wall motion, an exact agreement of 97% (kappa=0.91) was found between CT and CMR.

CONCLUSION

Sixty-four-slice CT agreed well with CMR in LV function assessment, and had a superior accuracy than echocardiography and SPECT on EF estimation. Sixty-four-slice CT is considered a clinically acceptable and robust method to evaluate LV function.

Quantitative assessment of regional left ventricular wall thickness and thickening using 16 multidetector-row computed tomography: comparison with cine magnetic resonance imaging

PURPOSE

The purpose of this study was to investigate the feasibility of retrospective electrocardiography-gated multidetector-row computed tomography (MDCT) in the assessment left ventricular (LV) wall thickness and thickening and to test its validity compared to cine magnetic resonance imaging (MRI) as a standard of reference.

MATERIALS AND METHODS

We enrolled 19 patients who underwent both cardiac MDCT and cine MRI. End-diastolic wall thickness (EDWT) and end-systolic wall thickness (ESWT) were measured in 16 myocardial segments. Percent systolic wall thickening (%SWT) was generated from the EDWT and ESWT. Nondiagnostic myocardial segments were excluded. Correlation and agreement between MDCT and cine MRI were analyzed.

RESULTS

Segmental assessability values were 86.2% (262/304) and 92.1% (280/304) for MDCT and cine MRI, respectively. In assessable segments by both modalities (80.9%, 246/304), a significant correlation between MDCT and MRI was found (r = 0.89, 0.85, and 0.61, for EDWT, ESWT, and %SWT, respectively; all P < 0.05). Mean EDWT and ESWT values by MDCT were slightly lower than those by cine MRI (9.8 +/- 3.6 vs. 10.0 +/- 3.7 mm and 13.8 +/- 4.4 vs. 14.1 +/- 4.3 mm, respectively; both P < 0.01). Bland-Altman analysis revealed acceptable limits of agreement between MDCT and Cine MRI.

CONCLUSION

MDCT is a feasible method to assess regional LV wall thickness and systolic thickening.