Spectroscopic imaging of the water resonance with short repetition time to study tumor response to hyperoxia

摘要: A variety of treatments that modulate tumor oxygen tension are used clinically to improve the outcome radiotherapy. High resolution, noninvasive measurements effects these would greatly facilitate development improved therapies and could guide treatment cancer patients. Previous work demonstrated magnetic resonance (MR) gradient echo imaging water proton detects changes in T 2 * T, tumors during hyperoxia may reflect increased oxygenation. This report describes use high resolution MR spectroscopic with short repetition time (TR = 0.2 s) accuracy which 1 measured. Mammary adenocarcinomas grown hind limbs rats were studied. Carbogen inhalation was induce hyperoxia. single 2-mm slice through center underlying muscle imaged at 4.7 Tesla in-plane approximately 1.2 mm frequency 5.8 Hz. The peak integral by an average 6% carbogen suggesting a decrease (n 8, P < 0.001). Peak height 15% large difference between increases demonstrates width decreased. Assuming Lorentzian lineshape, increase 12% observed tumors. In muscle, slightly (about 1.2% 3%, respectively; 0.02) but no significant change observed. Spectroscopic accurately reproducibly signal-to-noise ratio allows clear separation effects. Increases be due decreased deoxyhemoglobin blood vessels (i.e., BOLD effect) provide useful index