Document Detail

Thallium 201 for assessment of myocardial viability.
MedLine Citation:
PMID:  1948113     Owner:  NLM     Status:  MEDLINE    
Left ventricular (LV) performance is reduced in a large subset of patients with chronic coronary artery disease (CAD) and LV dysfunction on the basis of regionally ischemic or hibernating myocardium rather than irreversibly infarcted tissue. The detection of dysfunctional but viable myocardium is clinically relevant since regional and global LV function in such patients will improve after revascularization procedures; however, the identification of patients with such potentially reversible LV dysfunction is difficult. Although thallium 201 imaging may be of value in detecting viable myocardium if regions with perfusion defects during exercise demonstrate redistribution of thallium on a 3- to 4-hour resting image, thallium defects often appear persistently "fixed" within regions of severely ischemic or hibernating myocardium. It has been shown that up to 50% of regions with apparently irreversible thallium defects will improve in function after revascularization. Thus, standard exercise-redistribution thallium scintigraphy may not differentiate LV dysfunction arising from infarcted versus hibernating myocardium. The precision with which thallium imaging identifies viable myocardium can be improved greatly by additional studies once 4-hour redistribution imaging demonstrates an irreversible thallium defect. These additional studies include late (24-hour) redistribution imaging, repeat imaging after thallium reinjection, or a combination of thallium reinjection followed by late imaging. Several recent studies suggest that thallium reinjection techniques, by demonstrating thallium uptake in dysfunctional regions with apparently irreversible defects, predict improvement after revascularization with similar predictive accuracy as that achieved using metabolic imaging with positron emission tomography (PET). Studies directly comparing such thallium methods and PET, which thus far involve only small numbers of patients, suggest that the assessment of regional metabolic activity using PET and the assessment of regional thallium activity using single photon emission computed tomography provide concordant results. These findings, if confirmed by larger ongoing studies, suggest that thallium reinjection imaging is a convenient, clinically accurate, and relatively inexpensive method with which to identify viable myocardium in patients with chronic CAD and LV dysfunction.
R O Bonow; V Dilsizian
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Publication Detail:
Type:  Comparative Study; Journal Article; Review    
Journal Detail:
Title:  Seminars in nuclear medicine     Volume:  21     ISSN:  0001-2998     ISO Abbreviation:  Semin Nucl Med     Publication Date:  1991 Jul 
Date Detail:
Created Date:  1991-11-27     Completed Date:  1991-11-27     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  1264464     Medline TA:  Semin Nucl Med     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  230-41     Citation Subset:  IM    
Cardiology Branch, National Heart, Lung, and Blood Institute, Bethesda, MD 20892.
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MeSH Terms
Coronary Disease / physiopathology,  radionuclide imaging
Heart / radionuclide imaging*
Thallium Radioisotopes / diagnostic use*
Tomography, Emission-Computed
Tomography, Emission-Computed, Single-Photon / methods
Ventricular Function, Left
Reg. No./Substance:
0/Thallium Radioisotopes
Comment In:
Semin Nucl Med. 1991 Jul;21(3):170-2   [PMID:  1835135 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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