Semiquantitative assessment of myocardial perfusion using magnetic resonance imaging: evaluation of appropriate thresholds and segmentation models.
OBJECTIVE
The aim of the study was to determine optimal thresholds for semiquantitative perfusion parameters and to evaluate the influence of different segmentation models in detecting malperfused regions.


METHODS
In 6 healthy subjects and 13 patients with coronary artery disease, contrast-enhanced first-pass perfusion imaging was performed using a SR-TrueFISP-sequence. Thresholds for semiquantitative parameters were established, and different segmentation models of the left ventricular myocardium were tested. The standard of reference for patient studies was single photon emission computed tomography.


RESULTS
Optimal thresholds were determined in healthy subjects for the perfusion parameters upslope, AUC, and peak SI of mv-0.5*std, mv-1.5*std, and mv-1.0*std, respectively. Using the optimal threshold for each parameter/segmentation combination sensitivities and specificities of stress studies were between 66% and 93% and 77% and 92%, respectively. Subdivision of radial segments into subendo/subepicardial segments increased sensitivities for perfusion deficits.


CONCLUSIONS
Subdivision of radial myocardial segments is essential in analysis of magnetic resonance first-pass perfusion series. Semiquantitative perfusion parameters possess different sensitivities for the detection of perfusion deficits.
Department of Diagnostic Radiology, Division of Cardiology, Eberhard-Karls-University, Tuebingen, Germany. michael.fenchel@med.uni-tuebingen.de
Michael
M
Fenchel
Ulrich
U
Kramer
Uwe
U
Helber
Norbert I
NI
Stauder
Andreas
A
Franow
Claus D
CD
Claussen
Stephan
S
Miller
D000328:Adult; D000368:Aged; D003287:Contrast Media; D003326:Coronary Circulation; D003327:Coronary Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon
D003287:Contrast Media; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C078700:technetium tc-99m tetrofosmin; D019786:Gadolinium DTPA