Development ofa new MR compatible biopsy needle without effects of the direction of static magnetic field

点击翻译按钮获取中文摘要

Apparent diameters ofMR compatible needles by susceptibility artifact on MRI are changed for the direction against the direction of static magnetic field. The effect by the direction of static magnetic field will be revised with the changeable susceptibility of needles. The needle is composed of the mandrel and outer column. So the susceptibility effect of the whole needle will be able to be changed by altering the susoeptibility of the mandrel.We madethe mandrelsofNi-Cr-Mo alloy, Ni-Cr alloy and stainless steel alloy, and outer columns of Ni-Cr-Mo with 18 Gage diameter. MRI of each mandrels, outer columns and those combination were obtained with the following sequence ; spin echo (TR/TE 200/17), gradient echo (TR/TE/FA 200/13/25, 200/30/25), fast spoiled gradient echo (TR/TE/FA 180/5.5/90, 180/20/90). In susceptibility effect of the mandrel, that ofstainless steel was the strongest and that of Ni-Crwas the weakest, hi susceptibility effect of the whole needle by combination of the mandrels and the column, the result was the same as the mandrels. When the needle with Ni-Cr mandrel was set up at the perpendicular (90 degree) to the direction ofstatic magnetic field, the apparent diameters of the needle with Ni-Cr-Mo mandrel and stainless steel mandrel should be the same diameters as that of the needle with Ni-Crmandrelatthe angle of 70 degree and 30 degree.We designed a new MR compatible biopsy needle of which an apparent diameter on MRI could be changed.