[Transmyocardial laser revascularization--the initial experiences of imaging in MRT].
OBJECTIVE
Imaging of myocardial signal alteration and perfusion differences after transmyocardial laser revascularization (TMLR).


METHODS
5 patients suffering from coronary vessel disease underwent MRI (0.5 T) pre- and 4-7 d post-TMLR. T1-weighted spin echo sequences were acquired ECG-triggered native and after injection of gadolinium. Qualitative analysis was performed on both native and contrast-enhanced images. Myocardial signal alterations and wall changes were evaluated. Qualitative and quantitative analyses of contrast-enhanced images were performed with regard of post-therapeutic perfusion differences. Analysis was based on contrast-to-noise (C/N) data obtained from operator defined "regions of interest".


RESULTS
Visualization of laser-induced channels was not possible. Native scans obtained before and after TMLR revealed no significant change with regard to the qualitative analysis. Both qualitative and quantitative analyses demonstrated a posttherapeutic increase of C/N in both the left ventricular myocardium (64.4 pre-TMLR; 89.1 post-TMLR; p = 0.06) and the septum in the majority of cases. No significant difference between laser-treated left myocardium and untreated septum was observed (p > 0.05).


CONCLUSIONS
Single myocardial laser channels could not be visualized with a 0.5-T MRI. However, visualization of increased myocardial contrast enhancement in laser-treated left ventricular myocardium was evident in the majority of cases on the basis of qualitative and quantitative analyses.


CONCLUSIONS
The MRI technique used enabled a first, limited depiction of TMLR-induced myocardial changes. The clinical value and impact still have to be defined.
Abteilung für Röntgendiagnostik Radiologische Klinik, Universitäts-Krankenhaus Eppendorf, Hamburg.
C
C
Weber
R
R
Maas
P
P
Steiner
M
M
Beese
M
M
Hvalic
M
M
Stubbe
E
E
Bücheler
D000368:Aged; D003287:Contrast Media; D003327:Coronary Disease / Q000175:diagnosis / Q000601:surgery; D019786:Gadolinium DTPA; D006801:Humans; D053685:Laser Therapy / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods; D008297:Male; D008875:Middle Aged; D009204:Myocardial Revascularization / Q000379:methods*; D009206:Myocardium / Q000473:pathology; D018579:Patient Selection
D003287:Contrast Media; D019786:Gadolinium DTPA
Transmyokardiale Laserrevaskularisation--erste Erfahrungen der Bildgebung in der MRT.