Springer Fabian, Martirosian Petros, Boss Andreas, Claussen Claus D, Schick Fritz
Section on Experimental Radiology, Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Germany.
Top Magn Reson Imaging. 2010 Jun;21(3):141-8. doi: 10.1097/RMR.0b013e3181e8f9b9.
Introduction of high-field-strength whole-body MR scanners to clinical routine made abdominal magnetic resonance (MR) imaging widely available. Higher field strength provides improved signal yield, but other issues such as shorter wavelength and increased power deposition of radiofrequency in tissue must also be taken into account. This review describes current problems and future opportunities of abdominal MR imaging at 3.0 T under special consideration of relevant physical properties and technical challenges: impact of higher field strength on signal-to-noise ratio, Larmor frequency, and chemical shift effects are elucidated in detail. Furthermore, changes in longitudinal and transverse relaxation times as well as increased susceptibility effects at 3.0 T are reported. General safety issues and limitations in radiofrequency power deposition are discussed. Subsequently, implications of the previously mentioned changed MR properties at 3.0 T on clinical abdominal examinations applying different sequence types are described.
高场强全身磁共振成像扫描仪引入临床常规后，腹部磁共振成像得以广泛应用。更高的场强可提高信号输出，但还必须考虑其他问题，如波长更短以及组织中射频功率沉积增加。本综述描述了3.0 T腹部磁共振成像当前存在的问题和未来的机遇，并特别考虑了相关物理特性和技术挑战：详细阐述了更高场强对信噪比、拉莫尔频率和化学位移效应的影响。此外，还报告了3.0 T时纵向和横向弛豫时间的变化以及敏感性效应增加的情况。讨论了一般安全问题和射频功率沉积的局限性。随后，描述了上述3.0 T磁共振特性变化对应用不同序列类型的临床腹部检查的影响。
