Harald Braun

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PURPOSE In simultaneous positron emission tomography/magnetic resonance (PET/MR) imaging, local receiver surface radiofrequency (RF) coils are positioned in the field-of-view (FOV) of the PET detector during PET/MR data acquisition and potentially attenuate the PET signal. For flexible body RF surface coils placed on top of the patient's body, MR-based(More)
OBJECTIVES Attenuation correction of positron emission tomographic (PET) data is critical in providing accurate and quantitative PET volumes. Deriving an attenuation map (μ-map) from magnetic resonance (MR) volumes is a challenge in PET/MR hybrid imaging. The difficulty lies in differentiating cortical bone from air from standard MR sequences because both(More)
PURPOSE Flexible radiofrequency (RF) surface coils used in simultaneous PET/MR imaging are currently disregarded in PET attenuation correction (AC) since their position and individual geometry are unknown in whole-body patient scans. The attenuation of PET emission data due to the presence of RF surface coils has been investigated by several research groups(More)
OBJECTIVES Integrated whole-body positron emission tomography (PET)/magnetic resonance (MR) scanners have recently been introduced and potentially offer new possibilities in hybrid imaging of oncologic patients. Integration of PET in a whole-body MR system requires new PET detector technology and new approaches to attenuation correction of PET data based on(More)
PURPOSE With the recent introduction of integrated whole-body hybrid positron emission tomography/magnetic resonance (PET/MR) scanners, simultaneous PET/MR breast imaging appears to be a potentially attractive new clinical application. In this study, the technical groundwork toward performing simultaneous PET/MR breast imaging was developed and(More)
UNLABELLED In current PET/MR systems, the data acquisition paradigm is based on a multistation examination, imaging the patient from hip to head. This strategy has potential limitations, especially in terms of workflow and PET acquisition efficiency. In this work, the technical implementation of simultaneous PET and MR data acquisition with continuous table(More)
UNLABELLED Photon-deficient areas in 99mTc/111 in white blood cell (WBC) images for diagnosing vertebral osteomyelitis have been published often. This study retrospectively evaluated whether the use of 99mTc-labeled monoclonal antigranulocyte antibodies (BW 250/183) is superior to WBC and whether it offers higher specificity. METHODS The study included 81(More)
PURPOSE In quantitative PET imaging, it is critical to accurately measure and compensate for the attenuation of the photons absorbed in the tissue. While in PET/CT the linear attenuation coefficients can be easily determined from a low-dose CT-based transmission scan, in whole-body MR/PET the computation of the linear attenuation coefficients is based on(More)
BACKGROUND In integrated PET/MR hybrid imaging the evaluation of PET performance characteristics according to the NEMA standard NU 2-2007 is challenging because of incomplete MR-based attenuation correction (AC) for phantom imaging. In this study, a strategy for CT-based AC of the NEMA image quality (IQ) phantom is assessed. The method is systematically(More)
For decades, the heel effect has been known to cause an angular dependence of the emitted spectrum of an x-ray tube. In radiography, artifacts were observed and attributed to the heel effect. However, no problems due to the heel effect were discerned in multi-slice computed tomography (MSCT) so far. With flat-detector CT (FDCT), involving larger cone angles(More)