Radial Scan法のフローアーチファクト抑制効果について

摘要

Cartesian法において，フローアーチファクトは位相方向に発生し，診断の妨げとなる．現在，フローアーチファクト対策として，flow compensation，presaturationpulse，心電同期，位相方向と周波数方向の入れ替えなどが用いられている．しかし，これらの対策法ではそれぞれecho time（TE）の延長，撮像時間の延長，specific absorption rate（SAR）の増加が問題となるので，部位や症例に応じて使い分ける必要がある．さらにいずれの方法でもフローアーチファクトを完全に抑制することはできない．%Radial scan method collects blades rotated about the k-space origin. The one blade is the group of the echo acquired each repetition time (TR) in concentric strips. Because each of the blades has the phase-encode direction, it can be expected to be dispersing flow artifact which appear in the phase-encode direction. We examined how to produce flow artifact in radial scan method without motion correction. Flow artifact does not appear like a mass in radial scan method. Background noise in radial scan method tended to decrease when width of the blade is thinner and a number of blades is larger under a number of echo is keeping. In conclusion, unlike past countermeasures against flow artifact in Cartesian method, flow artifact becomes inconspicuous to be dispersed by 360 degrees in radial scan method.