Publication Type:Journal Article
Source:J Cardiovasc Magn Reson, Volume 7, Issue 2, p.487-94 (2005)
Keywords:Algorithms, Contrast Media, Gadolinium DTPA, Humans, Image Enhancement, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Cine, Middle Aged, Myocardium, Necrosis, Organophosphorus Compounds, Organotechnetium Compounds, Radiopharmaceuticals, Tomography, Emission-Computed, Single-Photon
PURPOSE: Contrast magnetic resonance (CMR) can identify myocardial necrosis after gadolinium administration as a hyperenhanced (HE) area. Yet there are no software tools that can effectively quantify such an area. The aim of this study is to develop a robust and effective algorithmic method for defining the extent of myocardial necrosis evidenced through CMR.
METHOD: Fifteen patients with previous myocardial infarction underwent nitrate Tetrofosmin G-SPECT and CMR. A software tool was developed, allowing semiautomatic detection of endocardial and epicardial borders and the automatic detection of HE regions. The accuracy of the proposed quantitative method of analysis has been tested with G-SPECT analysis that it is less than an ideal method for assessing myocardial viability, but at present is accepted and widely used in the clinical arena.
RESULTS: Segmental (SEHE) and global extension of HE were evaluated. HE was present in 161 of the 255 analyzed segments. Of the 161 HE segments, the mean SEHE was 36 +/- 30%. The operator independence (intraobserver: r = 0.97, p < 0.0001, interobserver: r = 0.95, p < 0.0001) was good and significant, with noticeable time savings with respect to manual analysis. There was strong and inverse correlation between SEHE and scintigraphic regional uptake reduction (r = -0.66, p < 0.0001), and also a positive correlation between SEHE and SPECT defect extension (r = 0.75, p < 0.0001). When assessing the global extent of necrosis, the correlation between the two techniques was strong (r = 0.79, p = 0.0004).
CONCLUSIONS: The proposed method of quantifying myocardial necrosis by CMR is highly reliable, reproducible, and operator-independent for quantifying.