An investigation of the performance of a coaxial HPGe detector operating in a magnetic resonance imaging field

作者：Harkness L J^*; Boston A J; Boston H C; Cole P; Cresswell J R; Filmer F; Jones M; Judson D S; Nolan P J; Oxley D C; Sampson J A; Scraggs D P; Slee M J; Bimson W E; Kemp G J; Groves J; Headspith J; Lazarus I; Simpson J; Cooper R J

来源：Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment , 2011, 638(1): 67-73.

DOI：10.1016/j.nima.2011.02.034

• Germanium detector
• Semiconductor
• Magnetic field
• MRI

Nuclear medical imaging modalities such as positron emission tomography and single photon emission computed tomography are used to probe physiological functions of the body by detecting gamma rays emitted from biologically targeted radiopharmaceuticals. A system which is capable of simultaneous data acquisition for nuclear medical imaging and magnetic resonance imaging is highly sought after by the medical imaging community. Such a device could provide a more complete medical insight into the functions of the body within a well-defined structural context. However, acquiring simultaneous nuclear/MRI sequences are technically challenging due to the conventional photomultiplier tube readout employed by most existing scintillator detector systems. A promising solution is a nuclear imaging device composed of semiconductor detectors that can be operated with a standard MRI scanner. However, the influence of placing a semiconductor detector such as high purity germanium (HPGe) within or close to the bore of an MRI scanner, where high magnetic fields are present, is not well understood. In this paper, the performance of a HPGe detector operating in a high strength static (B(s)) MRI field along with fast switching gradient fields and radiofrequency from the MRI system has been assessed. The influence of the B(s) field on the energy resolution of the detector has been investigated for various positions and orientations of the detector within the magnetic field. The results have then been interpreted in terms of the influence of the B(s) field on the charge collection properties. MRI images have been acquired with the detector situated at the entrance of the MRI bore to investigate the effects of simultaneous data acquisition on detector performance and MRI imaging.

• 出版日期2011-5-11