A fast and effective method to assess myocardial necrosis by means of contrast magnetic resonance imaging.
OBJECTIVE
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.


METHODS
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.
Positano
Vincenzo
V
CNR Institute of Clinical Physiology, Pisa, Italy. positano@ifc.cnr.it
Pingitore
Alessandro
A
Giorgetti
Assuero
A
Favilli
Brunella
B
Santarelli
Maria Filomena
MF
Landini
Luigi
L
Marzullo
Paolo
P
Lombardi
Massimo
M
D000465:Algorithms; D003287:Contrast Media; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D009336:Necrosis; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D003287:Contrast Media; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C078700:technetium tc-99m tetrofosmin; D019786:Gadolinium DTPA