Comparison of current density viability imaging at rest with FDG-PET in patients after myocardial infarction

Goernig, M.; Haueisen, J.; Schreiber, J.; Leder, U.; Hänninen, H.; Mäkelä, T.; Takala, P.; Nenonen, J.; Lauerma, K.; Knuuti, J.; Mäkijärvi, M.; Toivonen, L.; Katila, T.

doi:10.1016/j.compmedimag.2008.09.002

« Previous Next »Computerized Medical Imaging and Graphics
Volume 33, Issue 1 , Pages 1-6, January 2009

Comparison of current density viability imaging at rest with FDG-PET in patients after myocardial infarction

M. Goernig
- Clinic of Internal Medicine I, University Hospital of Jena, Erlanger Allee 101, 07747 Jena, Germany
- Corresponding author. Tel.: +49 3641 9324529; fax: +49 3641 9324177.
J. Haueisen
- Biomagnetic Center, Clinic of Neurology, University Hospital of Jena, Jena, Germany
- University of Technology Ilmenau, Ilmenau, Germany
J. Schreiber
- Biomagnetic Center, Clinic of Neurology, University Hospital of Jena, Jena, Germany
U. Leder
- Clinic of Internal Medicine I, University Hospital of Jena, Erlanger Allee 101, 07747 Jena, Germany
H. Hänninen
- Engineering Centre, BioMag Laboratory, Helsinki University Central Hospital, Helsinki, Finland
- Division of Cardiology, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland
T. Mäkelä
- Laboratory of Biomedical Engineering, Helsinki University of Technology, Espoo, Finland
P. Takala
- Engineering Centre, BioMag Laboratory, Helsinki University Central Hospital, Helsinki, Finland
- Laboratory of Biomedical Engineering, Helsinki University of Technology, Espoo, Finland
J. Nenonen
- Engineering Centre, BioMag Laboratory, Helsinki University Central Hospital, Helsinki, Finland
- Laboratory of Biomedical Engineering, Helsinki University of Technology, Espoo, Finland
K. Lauerma
- Department of Radiology, Helsinki University Central Hospital, Helsinki, Finland
J. Knuuti
- Turku PET Centre, Turku, Finland
M. Mäkijärvi
- Division of Cardiology, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland
L. Toivonen
- Division of Cardiology, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland
T. Katila
- Laboratory of Biomedical Engineering, Helsinki University of Technology, Espoo, Finland

Received 15 May 2008; accepted 22 September 2008.

Abstract

The assessment of myocardial viability is a major diagnostic challenge in patients with coronary artery disease (CAD) after myocardial infarction. Novel threedimensional current density (CD) imaging algorithms use high-resolution magnetic field mapping to determine the electrical activity of myocardial segments at rest. We, for the first time, compared CD activity obtained with several algorithms to 18-F-fluoro-deoxyglucose positron emission tomography (FDG-PET) in evaluation of myocardial viability. Magnetic field maps were obtained in nine adult patients (pt) with CAD and a history of infarction. The criterion for non-viable myocardium was an FDG-PET uptake with less than 45% of the maximum in the respective segments. CD imaging was applied to the left ventricle by using six different methods to solve the inverse problem. Mean CD activity was calculated for a close meshed grid of 90 locations of the left ventricle. A cardiologist compared bull's eye plots of CD and FDG-PET activity by eye. Spearman's correlation coefficients and specificity at a given level of sensitivity (70%) were calculated. Bull's eye plots revealed a significant correlation of CD/PET in 5 pt and no correlation in 3 pt. One pt had a negative correlation. The six different CD reconstruction methods performed similar. While CD reconstruction has the principal potential to image viable myocardium, we found that the reconstructed CD magnitude was low in scar segments but also reduced in some segments with preserved metabolic activity under resting conditions. New vector measurement techniques, the use of additional stress testing and advances in mathematical methodology are expected to improve CD imaging in future.

Keywords: Biomagnetism, Positron emission tomography, Cardiography, Inverse problems