Nichtinvasive Beurteilung aortokoronarer Venenbrücken mit Kernspintomographie^{[*] [**]}

Fortyfour patients with recent cardiac catheterization because of recurrent chest pain after coronary artery bypass surgery were studied by magnetic resonance imaging to evaluate graft patency. To assess the efficacy of this non-invasive method 92 coronary artery bypass grafts were examined by the spin-echo technique. ECG-gated transversal sections were acquired between the diaphragm and the aortic arch. The specificity of magnetic resonance imaging was 83% (48/58) for patent grafts. However, the sensitivity in the detection of occluded bypasses was only 56% (19/34). Despite the good specificity, clinical applications of this method are limited because of its low sensitivity.

Zusammenfassung

Die nichtinvasive Funktionsbeurteilung aortokoronarer Venenbrücken und koronarer Anschlüsse der Arteria mammaria interna ist besonders bei Patienten mit postoperativ erneut aufgetretenen pektangiösen Beschwerden von klinischem Interesse. In diesem Zusammenhang wurde die Aussagefähigkeit der Kernspintomographie bei der Beurteilung von Bypässen untersucht. Bei 44 Patienten mit insgesamt 92 Bypässen wurden kernspintomographisch transversale, EKG-getriggerte Schichten in Spin-Echo- Technik angefertigt. Zum Vergleich dienten angiographische Befunde, die bei allen Patienten innerhalb eines Monats erhoben wurden. Die Kernspintomographie zeigte eine gute Spezifität von 83% (48/58) bei der Erkennung offener Koronarbypässe. Allerdings war die Sensitivität zur Erkennung verschlossener Bypässe mit 56% (19/34) nicht ausreichend. Wegen vielfacher Clip-Artefakte konnten alle 4 Mammaria-interna-Bypässe zum Ramus interventrikularis anterior nicht beurteilt werden.

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