Magnetic resonance imaging of rodent tumors using radiofrequency gradient echoes

摘要: Abstract This paper evaluates the use of radiofrequency (RF) magnetic field gradient echoes to provide contrast in resonance (MR) images model tumors. Decay RF as a function evolution time was measured and sensitivity decay changes blood pressure evaluated. Previous investigators have demonstrated that static (B 0 ) MR image which is sensitive rate self-diffusion tissue water may also be perfusion. Gradient produced by gradients useful alternative conventional B methods. Unlike are relatively insensitive local susceptibility eddy currents. Differences between two methods particularly significant for studies tumors where large concentrations deoxyhemoglobin other paramagnetic substances cause gradients. Mammary adenocarcinomas subcutaneously implanted flanks female Fisher rats were studied. Magnetic experiments performed at 2 T. A surface coil used an excite detect signals from The echo amplitude short long times analyzed independently calculate apparent diffusion coefficients (ADCs). preparation extremely stable standard error 10 consecutive measurements made over 30–60 min with strength 50 kHz/cm, duration 1 ms (i.e., cycles/cm), ( t d s generally ±0.8%. ADC calculated approximately 3 × −5 cm /s. longer 0.5 Both ADCs decreased immediately following sacrifice administration Hydralazine. demonstrate amplitudes can vivo high degree reproducibility suggest acute physiological method characterization prediction monitoring effects therapeutic agents.