A computer-based decision support system to assist radiologists in diagnosing and grading brain tumours has been developed by the multi-centre INTERPRET project. Spectra from a database of 1 H single-voxel spectra of different types of brain tumours, acquired in vivo from 334 patients at four different centres, are clustered according to their pathology, using automated pattern recognition techniques and the results are presented as a two-dimensional scatterplot using an intuitive graphical user interface (GUI). Formal quality control procedures were performed to standardize the performance of the instruments and check each spectrum, and teams of expert neuroradiologists, neurosurgeons, neurologists and neuropathologists clinically validated each case. The prototype decision support system (DSS) successfully classified 89% of the cases in an independent test set of 91 cases of the most frequent tumour types (meningiomas, low-grade gliomas and high-grade malignant tumours-glioblastomas and metastases). It also helps to resolve diagnostic difficulty in borderline cases. When the prototype was tested by radiologists and other clinicians it was favourably received. Results of the preliminary clinical analysis of the added value of using the DSS for brain tumour diagnosis with MRS showed a small but significant improvement over MRI used alone. In the comparison of individual pathologies, PNETs were significantly better diagnosed with the DSS than with MRI alone.

Bilateral inferior petrosal sinus sampling (BIPSS) is the most reliable procedure for distinguishing Cushing's disease from ectopic ACTH secretion. However, it is less reliable at predicting the lateralization of the pituitary corticotroph microadenoma. We sought to determine whether this could be improved by taking into account the pattern of venous drainage and the precise location of the catheters. We retrospectively studied data from 86 patients who underwent BIPSS. Cushing's disease was predicted in 74 patients, of whom 69 underwent transsphenoidal surgery. Surgical cure was obtained in 65 patients, with identification of a corticotroph microadenoma in 58 cases. In 49 patients the location of the microadenoma predicted by the intersinus ACTH gradient could be compared with the pathologist's data. BIPSS accurately predicted the lateralization of the microadenoma in only 57% of these patients. Prediction was improved to 71% when both venograms and catheters were symmetric (35 patients). In this subgroup accuracy was 86% in patients with both catheters in the inferior petrosal sinuses compared with 50% in patients with both catheters in the cavernous sinuses (CS). Two transient sixth nerve palsies occurred during CS catheterization. Our data suggest that BIPSS results are much improved when venous drainage is symmetric. Catheterization of CS did not improve the results and was less safe.

With precurved arrays, dislocation usually occurs in the ascending part of the basal turn of the cochlea. With straight flexible electrode arrays, the incidence of dislocation was lower, and it seems that straight flexible arrays have a higher chance of a confined position within the scala tympani than perimodiolar precurved arrays.

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