| Popis: |
Balanced steady-state free-precession (bSSFP) is an important pulse sequence that may be underutilized in abdominal and pelvic magnetic resonance imaging (MRI). bSSFP offers several advantages for abdominal and pelvic MRI that include: bright blood effects, a relative insensitivity to the dephasing effects which occur in structures with linear movement, low specific absorption rate (SAR), high signal-to-noise ratio (SNR), high spatial resolution, and rapid acquisition times. Bright blood effects can be exploited to diagnose or confirm vascular pathologies when gadolinium-enhanced imaging cannot be performed, is indeterminate, or is degraded by artifact. The relative insensitivity to dephasing artifact in areas of linear movement is useful when imaging the biliary, urinary, and gastrointestinal tracts where dephasing artifacts may mimic filling defects such as calculi or polyps. Low SAR imaging is important in pediatric and pregnant patients and may be useful in patients with medical devices that restrict SAR levels. Rapid acquisition times and high SNR are extremely valuable assets in abdominal and pelvic MRI and bSSFP (which can be performed as static or cine acquisitions) and can be added to most existing abdominal and pelvic protocols when deemed suitable without significantly prolonging examination times. This article reviews the fundamentals of bSSFP imaging, presents vascular and nonvascular applications of bSSFP in abdominal and pelvic MRI, and discusses potential limitations (including imaging artifacts) of bSSFP.5 J. Magn. Reson. Imaging 2017;45:11-20. |
Plný text