Effects of the sampling rate on spatial resolution and the signal-to-noise ratio in spin-echo MR imaging were calculated. The theoretical results suggest that as T2\* decreases, due to either static magnetic field inhomogeneities or shortened T2 relaxation times, the calculated optimum sampling rate
Effect of the rate of gadolinium injection on magnetic resonance pulmonary perfusion imaging
β Scribed by Shin Matsuoka; Katsuhiro Uchiyama; Hideki Shima; Hiroaki Terakoshi; Sonomi Oishi; Yoko Nojiri; Hitoshi Ogata
- Publisher
- John Wiley and Sons
- Year
- 2002
- Tongue
- English
- Weight
- 437 KB
- Volume
- 15
- Category
- Article
- ISSN
- 1053-1807
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
Purpose
To determine whether the injection rate of contrast agent affects the dynamics of enhancement of the pulmonary parenchyma on magnetic resonance (MR) pulmonary perfusion imaging.
Materials and Methods
Fifteen healthy volunteers underwent enhanced MR pulmonary perfusion imaging to evaluate the effects of different injection rates. Injection rates were 1, 3, or 5 mL/second. Regions of interest (ROIs) were chosen in the lung and aorta to analyze the change in signal intensity over time.
Results
As the injection rate increased, the peak enhancement occurred significantly earlier (P = 0.0012), but the peak enhancement signalβtoβnoise ratio (SNR) value was not affected (P = 0.25). With the 3β and 5βmL/second injection rates, images of both the pulmonary circulation and systemic circulation were obtained separately. However, with 1 mL/second, higher enhancement of the aorta was overlapped with peak enhancement of the lung tissue.
Conclusion
The injection rate affects the enhancement profiles of the pulmonary parenchyma. J. Magn. Reson. Imaging 2002;15:108β113. Β© 2002 WileyβLiss, Inc.
π SIMILAR VOLUMES
An ultrafast MR sequence was used to measure changes in signal intensity during the first pass of intravascular contrast through the pulmonary circulation. From this, mean transit time, relative blood volume, and relative blood flow were calculated. Data were collected in an isogravitational plane i
The effect of irreproducible bulk tissue motions upon quantification of tissue perfusion and diffusion was studied via computer simulation of random phase error in conventional phase-encoded perfusion/diffusion MRI. Simulations using acquisition parameters typical for human brain studies demonstrate