Agreement and disagreement between contrast-enhanced magnetic resonance imaging and nuclear imaging for assessment of myocardial viability.
OBJECTIVE
The purpose of this study was to compare contrast-enhanced MRI and nuclear imaging with (99m)Tc-tetrofosmin and (18)F-fluorodeoxyglucose ((18)F-FDG) single photon emission computed tomography (SPECT) for assessment of myocardial viability.


METHODS
Included in the study were 60 patients with severe ischaemic left ventricular (LV) dysfunction who underwent contrast-enhanced MRI, (99m)Tc-tetrofosmin and (18)F-FDG SPECT. Myocardial segments were assigned a wall motion score from 0 (normokinesia) to 4 (dyskinesia) and a scar score from 0 (no scar) to 4 (76-100% transmural extent). Furthermore, (99m)Tc-tetrofosmin and (18)F-FDG segmental tracer uptake was categorized from 0 (tracer activity >75%) to 3 (tracer activity <25%). Dysfunctional segments were classified into viability patterns on SPECT: normal perfusion/(18)F-FDG uptake, perfusion/(18)F-FDG mismatch, and mild or severe perfusion/(18)F-FDG match.


RESULTS
Minimal scar tissue was observed on contrast-enhanced MRI (scar score 0.4+/-0.8) in segments with normal perfusion/(18)F-FDG uptake, whereas extensive scar tissue (scar score 3.1+/-1.0) was noted in segments with severe perfusion/(18)F-FDG match (p < 0.001). High agreement (91%) for viability assessment between contrast-enhanced MRI and nuclear imaging was observed in segments without scar tissue on contrast-enhanced MRI as well as in segments with transmural scar tissue (83%). Of interest, disagreement was observed in segments with subendocardial scar tissue on contrast-enhanced MRI.


CONCLUSIONS
Agreement between contrast-enhanced MRI and nuclear imaging for assessment of viability was high in segments without scar tissue and in segments with transmural scar tissue on contrast-enhanced MRI. However, evident disagreement was observed in segments with subendocardial scar tissue on contrast-enhanced MRI, illustrating that the nonenhanced epicardial rim can contain either normal or ischaemically jeopardized myocardium.
Roes
Stijntje D
SD
Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands. s.d.roes@lumc.nl
Kaandorp
Theodorus A M
TA
Marsan
Nina Ajmone
NA
Westenberg
Jos J M
JJ
Dibbets-Schneider
Petra
P
Stokkel
Marcel P
MP
Lamb
Hildo J
HJ
van der Wall
Ernst E
EE
de Roos
Albert
A
Bax
Jeroen J
JJ
D000368:Aged; D002309:Cardiology / Q000379:methods; D003287:Contrast Media / Q000494:pharmacology*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000494:pharmacology*; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D009943:Organophosphorus Compounds / Q000737:chemistry / Q000494:pharmacology*; D015609:Organotechnetium Compounds / Q000737:chemistry / Q000494:pharmacology*; D019275:Radiopharmaceuticals / Q000737:chemistry / Q000494:pharmacology*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000000981:diagnostic imaging
D003287:Contrast Media; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C078700:technetium tc-99m tetrofosmin