[en] Paragangliomas of the head and neck region - often incorrectly termed ''glomus tumors'' in everyday practice - are rare neoplasms that allow a radiologic diagnosis at first glance. They are found at four predilection sites; In the carotid bifurcation, at the parapharyngeal course of the vagal nerve, around the jugular foramen and in the tympanic cavity. Depending on their location and clinical manifestation they are diagnosed early or late. Therefore, their size may vary between few millimeters and several centimeters. Special problems arise when the tumors occur at multiple locations in the setting of genetic disease. Imaging is essential for establishing a diagnosis, for the description of their extension and for follow-up. Because of their high degree of vascularisation especially vagal and jugular paragangliomas are a challenge not only to the surgeon but also to the interventional neuroradiologist. Super-selective preoperative embolization can decide whether a tumor is operable or not. In individual cases infiltration of the carotid necessitates a temporary balloon test occlusion. (orig.)

[en] The aim of this study was the implementation of quantitative MR-Spectroscopy with external reference signals on a Philips Gyroscan Intera 1,5 T MR-Scanner for routine clinical use. We established measurements for quality assurance of the used phantoms and methods. In detail we analyzed the dependence of the signal on concentration and volume as well as on the local variation within the coil and the impact of these factors on quantification. Furthermore we established measurements for routine constancy checks. The method as well as the software for concentration calculation was checked by an in vitro measurement. In a blinded measurement the concentrations of NAA, Cho and Kr in the PTB reference phantom 10614 mM were determined correctly within their error limits. (orig.)

[en] In the first part of this contribution the authors report on the follow-up of patients, who at first presentation had both enhancing and non-enhancing MRI-lesions. The second part is confined to the use of MRI in monitoring disease evolution in controlled and pilot trials. (author). 9 refs.; 1 fig