Computer-assisted analysis of 4D cardiac MR image sequences after myocardial infarction.

OBJECTIVES: Spatial-temporal MR image sequences of the heart contain information about shape and motion changes and pathological structures after myocardial infarction. In this paper a Heart Analysis Tool (HeAT) for the quantitative analysis of 4D MR image sequences of infarct patients is presented. METHODS: HeAT supports interactive segmentation of anatomical and pathological structures. Registration of Cine- and DE-MR image data is applied to enable their combined evaluation during the analysis process. Partitioning of the myocardium in segments enables the analysis with high local resolution. Corresponding segments are generated and used for inter/intrapatient comparison. Quantitative parameters were extracted and visualized. RESULTS: Parameters like endocard movement in the infarcted area of six infarct patients were computed in HeAT. Parameters in the infarct area show the expected dysfunctional characteristics. Based on theses parameters passive endocardial movement and myocardial areas with decreased contraction could be identified. CONCLUSION: In contrast to other software tools HeAT supports the combination of contour information of Cine-MR and DE-MR, local analysis with high resolution and inter/intra patient comparison. HeAT enables an observer-independent evaluation of the complex cardiac image data. Using HeAT in further studies can increase the understanding of left ventricle (LV) remodeling.

[Comparison of an edema-sensitive HASTE-TIRM sequence with delayed contrast enhancement in acute myocardial infarcts]. / Vergleich der ödemsensitiven HASTE-TIRM-Sequenz mit der späten Kontrastmittelanreicherung bei akutem Myokardinfarkt.

GOAL: Comparison between a fluid-sensitive (HASTE-TIRM)-sequence and delayed contrast-enhancement in patients with acute myocardial infarct (AMI) in MRI. MATERIAL AND METHODS: 32 patients with AMI were imaged 7 +/- 4 days after the time of infarction with a 1.5 T unit using a T2 HASTE-TIRM and a contrast-enhanced (CE) T1 turbo FLASH sequence. A threshold method (>2 SD in comparison with normal myocardium) was used to quantify the hyperintense zones in both sequences. The transmurality of the hyperintense regions was measured on a segmental basis. RESULTS: The hyperintense areas were larger on the HASTE-TIRM sequence with 29.6 +/- 13.2 % of the left ventricular (LV) area as compared to the CE-MRI with 19.2 +/- 10 % of the LV area (p < 0.0001). The measured transmurality was higher with the HASTE-TIRM sequence than with the CE-MRI (p < 0.0001). While the correlation between CE-MRI and peak creatine kinase (CK max) was good (r = 0.59, p < 0.001), no correlation was found between the HASTE-TIRM sequence and CK max (r = 0.29, p = ns). CONCLUSIONS: The peri-infarct edema can be depicted with a HASTE-TIRM sequence in addition to the non-viable infarct zone. The HASTE-TIRM sequence shows a higher transmurality of the hyperintense regions than the CE-MRI. The additional area depicted by the HASTE-TIRM sequence could represent functionally impaired but viable myocardium).