Novel phase-based noise reduction strategy for quantification of left ventricular function and mass assessment by cardiac CT: Comparison with cardiac magnetic resonance

doi:10.1016/j.ejrad.2013.02.023

European Journal of Radiology

Volume 82, Issue 8, August 2013, Pages e337-e341

https://doi.org/10.1016/j.ejrad.2013.02.023 Get rights and content

Abstract

Background

Tube current modulation in retrospective ECG gated cardiac computed tomography (CT) results in increased image noise and may reduce the accuracy of left ventricular (LV) ejection fraction (EF) and mass assessment.

Objective

To examine the effects of a novel CT phase-based noise reduction (NR) algorithm on LV EF and mass quantification as compared to cardiac magnetic resonance (CMR).

Methods

In 40 subjects, we compared the LV EF and mass between CT and CMR. In a subset of 24 subjects with tube current modulated CT, the effect of phase-based noise reduction strategies on contrast-to-noise ratio (CNR) and the assessment of LV EF and mass was compared to CMR.

Results

There was excellent correlation between CT and CMR for EF (r = 0.94) and mass (r = 0.97). As compared to CMR, the limits of agreement improved with increasing strength of NR strategy. There was a systematic underestimation of LV mass by CT compared to CMR with no NR (−10.3 ± 10.1 g) and low NR (−10.3 ± 12.5 g), but was attenuated with high NR (−0.5 ± 8.3 g). Studies without NR had lower CNR compared to low and high NR at both the ES phase and ED phase (all p < 0.01).

Conclusions

A high NR strategy on tube current modulated functional cardiac CT improves correlation of EF compared to CMR and reduces variability of EF and mass evaluation by increasing the CNR. In an effort to reduce radiation dose with tube current modulation, this strategy provides better image quality when LV function and mass quantification is needed.

Section snippets

Background

Left ventricular (LV) ejection fraction (EF) and mass provide both diagnostic and prognostic information for various cardiac diseases [1], [2], [3], [4], [5], [6]. Advanced non-invasive imaging modalities such as computed tomography (CT) and cardiac magnetic resonance (CMR) can be used to assess LV EF and mass without relying on geometric assumptions or adequate acoustic windows. CMR assessment of LV EF and mass has been found to be highly reproducible and this modality is thus considered the

Study populations

We performed LV EF and mass assessment in 40 patients referred to our institution for cardiac CT angiography to investigate for suspected coronary artery disease. All patients had CT imaging performed with retrospective ECG gating and also underwent CMR within 7 days of cardiac CT. LV EF and mass assessed by CMR was used as the standard reference. A subgroup of 24 patients who received tube current modulated CT were used to test the effect of various noise reduction strategies. The local

Results

Table 1 summarizes the characteristics of the 40 patients who had both CT and CMR for analysis and the subgroup of 24 patients who had ECG-tube modulated CT scans. The CT radiation dose was lower in scans performed with tube current modulation compared to no tube current modulation (10.0 ± 4.9 mSv vs 14.4 ± 2.7 mSv, P = 0.003). However this was at the expense of lower CNR during both ES (8.3 ± 4.2 vs 11.6 ± 4.3, P = 0.02) and ED phases (6.2 ± 3.7 vs 12.6 ± 15.6, p < 0.001).

Discussion

In this study, we found excellent correlations for LV EF and LV mass assessed between cardiac CT and CMR. The application of a novel noise reduction strategy on cardiac CT datasets performed with tube current modulation showed an improvement in CNR with increasing strengths of NR as well as an improvement in the limit of agreement for the assessment of LV EF. When implementing a high NR strategy, the degree of systemic underestimation of LV mass compared to CMR was markedly reduced, with the

Conflict of interest

Sources of Funding: Dr. Quynh Truong received support from NIH grant K23HL098370 and L30HL093896 and research support from Qi Imaging.

Disclosures

Dr. Heather Brown works for Qi Imaging.

Other authors have no disclosure.

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Novel phase-based noise reduction strategy for quantification of left ventricular function and mass assessment by cardiac CT: Comparison with cardiac magnetic resonance

Abstract

Background

Objective

Methods

Results

Conclusions

Section snippets

Background

Study populations

Results

Discussion

Conflict of interest

Disclosures

Journal of the American College of Cardiology

Journal of the American College of Cardiology

JACC: Cardiovasc Imaging

American Heart Journal

Journal of the American College of Cardiology

Journal of Cardiovascular Computed Tomography

Ejection fraction, peak exercise oxygen consumption, cardiothoracic ratio, ventricular arrhythmias, and plasma norepinephrine as determinants of prognosis in heart failure. The V-HeFT VA Cooperative Studies Group

Circulation

Additional predictive value of both left and right ventricular ejection fractions on long-term survival in idiopathic dilated cardiomyopathy

European Heart Journal

Prognostic implications of echocardiographically determined left ventricular mass in the Framingham Heart Study

New England Journal of Medicine

Determination of left ventricular mass by magnetic resonance imaging in hearts deformed by acute infarction

Circulation