Dynamic motion analysis of fetuses with central nervous system disorders by cine magnetic resonance imaging using fast imaging employing steady-state acquisition and parallel imaging: a preliminary result.
OBJECTIVE
The authors present a novel cine magnetic resonance (MR) imaging, two-dimensional (2D) fast imaging employing steady-state acquisition (FIESTA) technique with parallel imaging. It achieves temporal resolution at less than half a second as well as high spatial resolution cine imaging free of motion artifacts for evaluating the dynamic motion of fetuses in utero. The information obtained is used to predict postnatal outcome.


METHODS
Twenty-five fetuses with anomalies were studied. Ultrasonography demonstrated severe abnormalities in five of the fetuses; the other 20 fetuses constituted a control group. The cine fetal MR imaging demonstrated fetal head, neck, trunk, extremity, and finger as well as swallowing motions. Imaging findings were evaluated and compared in fetuses with major central nervous system (CNS) anomalies in five cases and minor CNS, non-CNS, or no anomalies in 20 cases. Normal motility was observed in the latter group. For fetuses in the former group, those with abnormal motility failed to survive after delivery, whereas those with normal motility survived with functioning preserved. The power deposition of radiofrequency, presented as specific absorption rate (SAR), was calculated. The SAR of FIESTA was approximately 13 times lower than that of conventional MR imaging of fetuses obtained using single-shot fast spin echo sequences.


CONCLUSIONS
The following conclusions are drawn: 1) Fetal motion is no longer a limitation for prenatal imaging after the implementation of parallel imaging with 2D FIESTA, 2) Cine MR imaging illustrates fetal motion in utero with high clinical reliability, 3) For cases involving major CNS anomalies, cine MR imaging provides information on extremity motility in fetuses and serves as a prognostic indicator of postnatal outcome, and 4) The cine MR used to observe fetal activity is technically 2D and conceptually three-dimensional. It provides four-dimensional information for making proper and timely obstetrical and/or postnatal management decisions.
Guo
Wan-Yuo
WY
Department of Radiology, The Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.
Ono
Shigeki
S
Oi
Shizuo
S
Shen
Shu-Huei
SH
Wong
Tai-Tong
TT
Chung
Hsiao-Wen
HW
Hung
Jeng-Hsiu
JH
D004677:Encephalocele / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D005315:Fetal Diseases / Q000000981:diagnostic imaging / Q000473:pathology*; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008588:Meningocele / Q000000981:diagnostic imaging / Q000473:pathology; D009068:Movement; D009422:Nervous System Diseases / Q000000981:diagnostic imaging / Q000473:pathology*; D010865:Pilot Projects; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000295:instrumentation* / Q000379:methods*; D014103:Torticollis / Q000000981:diagnostic imaging / Q000473:pathology; D014463:Ultrasonography