There are a wide range of improvements in MRI technology since the first published MR image was presented in 1973. Many of the improvements, however, can be attributed to two aspects of MR imaging, increasing field strength and parallel imaging techniques. At The Canine Chiari Institute, we are equipped with the only 3 Tesla MRI in the world dedicated to veterinary imaging and recognize the benefits of better resolution, faster imaging requiring less anesthesia time, and CSF flow studies with each patient. High-Field Magnets
The magnet is the biggest, most expensive, and influential component of an MRI system. Recent years have been marked by a dramatic movement in clinical imaging from 0.5 T to 3.0 T imaging systems. The advantage of high field magnets lies in the improved signal-to-noise ratio (SNR) which clinically translates into improved resolution and shorter acquisition time.
Parallel imaging techniques
Parallel imaging techniques use arrays of RF coils to simultaneously collect data from the imaging volume. The most obvious benefit from the use of parallel imaging is the rapid acquisition of whole body images with high spatial resolution providing diagnostic detail in all areas of the image. Increased interest in whole body imaging has also led to the development of whole body diffusion weighted imaging which appears to have high sensitivity to metastatic deposits and other pathological processes. The focus of these comments has been on the introduction of high field magnets and parallel imaging acquisitions since they represent the greatest impact on clinical MRI in recent years. However, software developments also deserve brief mention. Most systems now have specially designed interfaces which minimize the technical intervention required by the operator and instead rely on the automated selection of imaging protocols based on clinically driven menus. Automation of the examination procedure allows high quality examinations to be performed by relatively less experienced technical staff. Phased-array or CINE MRI is a series of traditional MR images corresponding to multiple, evenly spaced, phases of the cardiac cycle. Images are retrospectively reconstructed corresponding to several phases of the cardiac cycle and sequentially linked in order to produce a cinematic display. The cine images can be used to evaluate fluid dynamics and ARE commonly used to assess cardiac function and CSF flow.