Regensburg 2007 – wissenschaftliches Programm
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ST: Fachverband Strahlen- und Medizinphysik
ST 1: Medizinische Bildgebung I
ST 1.7: Vortrag
Montag, 26. März 2007, 12:00–12:15, Ch 12.0.16
Aging Effects in BOLD MRI of the Human Calf Muscles during Reactive Hyperemia — •Anja-Carina Schulte1, Hans Peter Ledermann2, and Deniz Bilecen2 — 1Universitätsklinik Ulm, Klinik für Strahlentherapie, Ulm — 2Universitätsspital Basel, Institut für Diagnostische Radiologie, Basel, Schweiz
The blood oxygenation level-dependent (BOLD) effect that relies on the different magnetic properties of oxy- and deoxyhemoglobine can be applied to measure signal changes in skeletal muscles. This muscle BOLD effect is not yet completely understood but is assumed to primarily reflect blood oxygenation changes at tissue level.*Our study compares the muscle BOLD effect in the calf of 11 elderly and 17 young healthy volunteers during reactive hyperemia, which was provoked by 360 s of suprasystolic thigh compression. A fat-suppressed multi-echo GE-EPI sequence (TR=1 s) was used to acquire 360 s of hyperemia. Our comparison was based on 3 characteristic parameters of the BOLD signal time-course: hyperemia-peak-value, time-to-peak, and end-value.*The BOLD signal rapidly increased after cuff deflation reaching a maximum, which was significantly reduced (p<0.005) and earlier (p<0.05) in the elderly. After the maximum, the BOLD signal remained rather constant, whereas it nearly returned to baseline in the young (p<0.001).*Calf muscle BOLD MRI revealed statistically significant differences. The reduced and shortened increase in elderly reflects decreased oxygenation of muscle tissue probably due to age-related impairment of inflow. The following reduced decrease may be explained by diminished outflow and thus delayed clearance of oxygenated blood.