Identifizierung des vitalen Myokards mit der ²⁰¹T1-Szintigraphie: Ein Vergleich der Methoden

Zusammenfassung

Es wurden die Ergebnisse der Standardtechnik Stress-Redistribution, (R1) mit jenen nach Reinjektion von 37 MBq sofort nach der ersten Spätaufnahme und Bilddokumentation nach 15 min (R2), mit jenen einer Spätaufnahme nach 24 h (R3) und mit jenen, die mit einer zeitlich versetzten Ruheinjektion (R4) gemacht wurden, bei 24 Patienten mit vorangegangenem Herzinfarkt verglichen. Die in drei Projektionsebenen angefertigten planaren Bilder wurden in 216 Segmente unterteilt. Die Anreicherung des ²⁰¹TI wurde mittels eines subjektiven Scores bzw. semiquantitativer Analyse der Flächen, die aus dem Circumferenzprofil gewonnen wurden, bewertet. Ein Speicherungsdefekt wurde unter Belastung in 127 Segmenten bestätigt (58,7%); die visuelle Analyse konnte eine verbesserte Anreicherung in R1 (32,3%), in R2 (41,7%), in R3 (33%) und in R4 (49,6%) feststellen. Die semiquantitative Bewertung hat nur mit der R1- Methode (62% der Fälle) eine Verbesserung erbracht. Es wurde bei 6 Patienten (25% der Fälle) vitales Myokard nachgewiesen, welches nicht mit der konventionellen Analyse identifiziert werden konnte.

Summary

The present study was undertaken to compare four different imaging approaches to evaluate uptake defect reversibility. 24 infarcted patients underwent standard stress/redistribution ²⁰¹TI imaging (R1). Then, after reinjection of 37 MBq of ²⁰¹ Tl, patients were re-imaged either after 15 min (R2) 24 h later (R3). A separate rest study (R4) following a new tracer injection was done within 2-3 days. Planar images were obtained in the standard three views and subdivided into 216 segments for qualitative analysis based on a visual score. A semiquantitative analysis based upon circumferential profiles was also applied. A stress defect was found in 127 segments (58.7%). By visual inspection reperfusion was considered to occur in 32.3%, 41.7%, 33.0% and 49.6% of the cases with R1, R2, R3, and R4, respectively. The semiquantitative method showed a high reperfusion only with R1 (62%), while the other procedures proved less effective. No improvement was found with R4. Six patients (25%) showed myocardial viability that was not detected with the early reinjection technique.

Schlüsselwörter

Myokardszintigraphie - vitales Myokard

Key words

Myocardial scintigraphy - viable myocardium

• LITERATUR

• 1 Abdulla A, Maddahi J, Garcia E. et al. Slow regional clearance of myocardial thallium 201 in the absence of perfusion defect: contribution to detection of individual coronary artery stenoses and mechanism for accurrence. Circulation 1985; 71: 72-9.
• 2 Althöfer C, Kaiser H-J, Dörr R. et al. Fluorine-18 deoxyglucose PET for assessment of viable myocardium in perfusion defects in ^99mTc-MIBI SPET: a comparative study in patients with coronary artery disease. Eur J Nucl Med 1992; 19: 334-42.
• 3 Bashour TT, Mason DT. Myocardial hibernation and “embalment”. Am Heart J 1990; 119: 706-8.
• 4 Beanlands RSB, Daward F, Wen WH. et al. Are the kinetics of technetium-99m metho- xyisobutil isonitrile affected by cell metabolism and viability?. Circulation 1990; 82: 1802-14.
• 5 Beller GA, Watson DD, Ackell P, Pohost GM. Time course of thallium 201 redistribution after transient myocardial ischemia. Circulation 1980; 61: 791-7.
• 6 Berman DS, Kiat H, Van KF. et al. Comparison of SPECT using technetium agents and thallium-201 and PET for the assessment of myocardial perfusion and viability. Am J Cardiol 1990; 66: 72E-79E.
• 7 Bonow RO, Dilsizian V, Cuocolo A, Bacharach SL. Identification of viable myocardium in patients with chronic coronary artery disease and left ventricular dysfunction. Comparison of thallium scintigraphy with reinjection and PET imaging with ¹⁸Fluoro- deoxyglucose. Circulation 1991; 83: 26-37.
• 8 Braunwald E, Rutherford JD. Reversible ischemic left ventricular dysfunction: evidence for the “hibernating myocardium”. J Am Coll Cardiol 1986; 08: 1467-70.
• 9 Brunken R, Schwaiger M, Grover-McKay M. et al. Positron emission tomography detects tissue metabolic activity in myocardial segments with persistent thallium perfusion defects. J Am Coll Cardiol 1987; 10: 557-67.
• 10 Cloninger KG, DePuey G, Garcia EV. et al. Incomplete redistribution in delayed thallium 201 single photon emission computed tomographic (SPECT) images: an overestimation of myocardial scarring. J Am Coll Cardiol 1988; 12: 955-63.
• 11 Dilsizian V, Rocco TP, Freedman NMT, Leon MB, Bonow RO. Enhanced detection of ischemic but viable myocardium by the reinjection of thallium after stress-redistribution imaging. N Engl J Med 1990; 323: 141-6.
• 12 Dondi M, Tartagni F, Fallani F. et al. A comparison of rest Sestamibi and rest - redistribution thallium single photon emission tomography: possible implications for myocardial viability detection in infarcted patients. Eur J Nucl Med 1993; 20: 26-31.
• 13 Freeman I, Grunwald AM, Hoory S, Bodenheimer MM. Effect of coronary occlusion and myocardial viability on myocardial activity of Technetium-99m-Sestamibi. J Nucl Med 1991; 32: 292-98.
• 14 Gibson RS, Watson DD, Taylor GJ. et al. Prospective assessment of regional myocardial perfusion before and after coronary revascularization surgery by quantitative thallium 201 scintigraphy. J Am Coll Cardiol 1983; 01: 804-15.
• 15 Grunwald AM, Watson DD, Holzgrefe Jr HH, Irving JF, Beller GA. Myocardial thallium 201 kinetics in normal and ischemic myocardium. Circulation 1981; 64: 610-8.
• 16 Gutman J, Berman DS, Freeman M. et al. Time to completed redistribution of thallium 201 in exercise myocardial scintigraphy: relationship to the degree of coronary artery stenosis. Am Heart J 1983; 106: 989-95.
• 17 Hör G, Baum RP. with the assistance of Maul. Myocardial perfusion. In: Handbook of Nuclear Medicine Vol. 2 “Heart”. Pabst HW, Adam WE, Ell P, Hör G, Kriegei H. (eds). Stuttgart: Gustav Fischer; 1992: 127-253.
• 18 Kiat H, Berman DS, Maddahi J. et al. Late reversibility of tomographic myocardial thallium 201 defects: an accurate marker of myocardial viability. J Am Coll Cardiol 1988; 12: 1456-63.
• 19 Klepzig H, Kaltenbach M. Exercise Stress Testing in Patients with Coronary Heart Disease. In: Handbook of Nuclear Medicine, Vol. 2 “Heart”. Pabst HW, Adam WE, Ell P, Hör G, Kriegei H. (eds). Stuttgart: Gustav Fischer; 1992: 57-73.
• 20 Liu P. Technetium-99m-Sestamibi: another window on myocardial viability?. J Nucl Med 1991; 32: 298-299.
• 21 Liu P, Kiess MC, Okada RD. et al. The persistent defect on exercise thallium imaging and its fate after mayocardial revascularization: does it represent scar or ischemia?. Am Heart J 1985; 110: 996-1001.
• 22 Melin JA, Wijns W, Keyeux A. et al. Assessment of thallium 201 redistribution versus glucose uptake as predictors of viability after coronary occlusion and reperfusion. Circulation 1988; 77: 927-34.
• 23 Pieri PL, Tisselli A, Moscatelli G, Acito P. La reiniezione di Tallio 201: una nuova metodica per l’identificazione del miocardio vitale nei pazienti con deficit fissi di capta- zione miocardica. G Ital Cardiol 1989; 19: 1086-93.
• 24 Pohost GM, Okada RD, O’Keefe DD. et al. Thallium redistribution in dogs with severe coronary artery stenosis of fixed caliber. Circ Res 1981; 48: 439-46.
• 25 Rahimtoola SH. The hibernating myocardium. Am Heart J 1989; 117: 211-21.
• 26 Rocco TP, Dilsizian V, McKusick KA. et al. Comparison of thallium redistribution with rest “reinjection” imaging for the detection of viable myocardium. Am J Cardiol 1990; 66: 158-63.
• 27 Tamaki N, Yonekura Y, Yamashita K. et al. Relation of left ventricular perfusion and wall motion with metabolic activity in persistent defects on thallium 201 tomography in healed myocardial infarction. Am J Cardiol 1988; 62: 202-8.
• 28 Yang DL, Berman DS, Kiat H. et al. The frequency of late reversibility in SPECT thallium 201 stress-redistribution studies. J Am Coll Cardiol 1990; 15: 334-40.
• 29 Ziessman HA, Keyes Jr JW, Fox LM, Green CE, Fox SM. Delayed redistribution in thallium 201 SPECT myocardial perfusion studies. Chest 1989; 96: 1031-5.