BOLD-MRI in ten patients with coronary artery disease: evidence for imaging of capillary recruitment in myocardium supplied by the stenotic artery.
Changes of myocardial oxygenation can be studied by measurements of the apparent transverse relaxation time T2*, which is correlated with the oxygenation state of hemoglobin. In this study, ten patients with coronary artery disease (CAD) underwent blood oxygenation level dependent (BOLD) T2* measurements using a segmented gradient echo pulse sequence with ten echoes. T2* measurements were performed in a single short-axis slice of the heart at rest and under pharmacological stress with dipyridamole (DIP), which increases myocardial blood flow. For comparison, all patients underwent X-ray angiography and stress-echocardiography within 4 days after the MR exam. In one patient, MR examination was repeated 10 weeks after percutaneous transluminal coronary angioplasty (PTA). In the differential T2* maps, expected ischemic areas of myocardium were identified in six patients. In these regions, T2+ values (30 +/- 8 ms) were significantly reduced when compared to the remaining myocardium (48 +/- 9 ms, P < 0.01). In four patients, the myocardial region of interest could not be assessed owing to severe susceptibility artifacts in the ischemic region. The success of the PTA treatment could be visualized from a more homogeneous DIP induced increase in T2* within the ischemic myocardium (from 26 +/- 1 to 29 +/- 1 ms before PTA versus 26 +/- 1 to 31 +/- 4 ms after PTA, P < 0.001).
Wacker
C M
CM
Forschungsschwerpunkt Radiologische Diagnostik und Therapie, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany.
Bock
M
M
Hartlep
A W
AW
Bauer
W R
WR
van Kaick
G
G
Pfleger
S
S
Ertl
G
G
Schad
L R
LR
D000328:Adult; D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D002196:Capillaries / Q000473:pathology; D003327:Coronary Disease / Q000175:diagnosis / Q000473:pathology* / Q000628:therapy; D003331:Coronary Vessels / Q000473:pathology; D004176:Dipyridamole; D004452:Echocardiography; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology; D010100:Oxygen / Q000097:blood; D014665:Vasodilator Agents
D014665:Vasodilator Agents; D004176:Dipyridamole; D010100:Oxygen