Affect the magnetic particles of the active area, and is implemented by a device for detecting magnetic particles and / or. The said apparatus comprising: a selecting means for generating a selection field, the magnetic field intensity space, the selection magnetic field, the working area is a large second sub-area of the magnetic field strength and the first sub-area small field strength driving means for changing the position of the second region and the first region in the working area has such a pattern is generated within, by means selection means, for driving the magnetic field, as well as a receiving means for obtaining a signal Meet, the signal depends on the magnetization of the working area, is influenced by changes in the position of the second sub-region and the first sub-region, the magnetization has a receiving means. The apparatus includes a magnetic field generator coil and surrounding. Coil surrounding the perimeter surrounding the magnetic field generating device almost completely.作用領域の磁性粒子に影響を及ぼし、及び/又は該磁性粒子を検出する装置によって実現される。当該装置は、選択用磁場を発生させる選択手段であって、前記選択用磁場は、該磁場強度空間内において、磁場強度の小さな第1サブ領域及び磁場強度の大きな第2サブ領域が前記作用領域内に生成されるようなパターンを有する、選択手段、駆動用磁場の手段によって前記作用領域内における前記第1領域及び第2領域の位置を変化させる駆動手段、並びに、信号を取得する受信手段であって、該信号は前記作用領域内の磁化に依存し、該磁化は前記第1サブ領域及び第2サブ領域の位置の変化による影響を受ける、受信手段を有する。当該装置は周囲を取り囲むコイル及び磁場発生装置を有する。前記周囲を取り囲むコイルはほぼ完全に前記磁場発生装置を取り囲む。
