Pixel-by-pixel calculation of T1 values (T1 mapping) has been used in different 
tissues to focus on T1 changes in a quantitative fashion. The aim of this study 
was to establish T1 mapping of human myocardium on a 1.5 Tesla system and to 
examine its diagnostic potential in patients with acute myocardial infarction 
(AMI). 8 patients with reperfused AMI (day 3 +/- 1) underwent multi-breath-hold 
MRI in a 1.5 Tesla system. Sets of five images with varying T1 weighting were 
acquired prior to and after the administration of contrast agent to generate 
images from calculated T1 values (T1 mapping). Prior to the contrast agent 
administration, all patients showed T1 prolongation in the area of infarction, 
which was identified in separate measurements using the delayed enhancement 
approach. Compared to noninfarcted areas, T1 values in the infarcted areas were 
increased by 18 +/- 7% (SE, p < 0.05). The spatial extent of the area of T1 
prolongation was larger than that of the hyper-enhanced areas in conventional 
contrast-enhanced images. T1 maps obtained after the application of 
Gadolinium-DTPA revealed a T1 reduction of 27 +/- 4% in infarcted tissue 
compared to noninfarcted areas (p < 0.05). The areas showing T1 reduction were 
in agreement with the hyper-enhanced regions in conventional T1-weighted images. 
T1 mapping visualizes changes in the longitudinal relaxation time induced by 
AMI. T1 mapping can detect myocardial necrosis without the use of contrast 
media. Information that can be extracted from a combination of pre- and 
postcontrast T1 maps exceeds that from conventional contrast studies.