A rapid dynamic imaging sequence has been developed in which only the 32 phase encoding steps that encode low spatial frequencies are collected for each dynamic image. These are substituted into a previously acquired, 128 x 128 raw data set prior to image reconstruction. In this way the dynamic information is retained while the overall appearance is improved in comparison with images obtained by zero filling to 128 x 128, leading to better qualitative evaluation. The limited k-space sampling means that the technique is most effective for large homogeneous areas of signal change since fine changes in contrast are imperfectly recorded.

Intraoperative 3-D ultrasound seems to provide a time- and cost-effective way to update high-quality 3-D maps used in neuronavigation.

In recent years there has been a considerable improvement in the quality of ultrasound (US) imaging. The integration of 3D US with neuronavigation technology has created an efficient and inexpensive tool for intra-operative imaging in neurosurgery. In this review we present the technological background and an overview of the wide range of different applications. The technology has so far mostly been applied to improve surgery of tumours in brain tissue, but it has also been found to be useful in other procedures such as operations for cavernous haemangiomas, skull base tumours, syringomyelia, medulla tumours, aneurysms, AVMs and endoscopy guidance.

Background and Purpose-Strokes have especially devastating implications if they occur early in life; however, only limited information exists on the characteristics of acute cerebrovascular disease in young adults. Although risk factors and manifestation of atherosclerosis are commonly associated with stroke in the elderly, recent data suggests different causes for stroke in the young. We initiated the prospective, multinational European study Stroke in Young Fabry Patients (sifap) to characterize a cohort of young stroke patients. Methods-Overall, 5023 patients aged 18 to 55 years with the diagnosis of ischemic stroke (3396) *Drs Rolfs, Fazekas and Grittner contributed equally to this work. Authors contributions: Dr Rolfs has conceptualized, initiated, and designed and organized the study, has been involved in the recruitment of the patients, and wrote significant parts of the manuscript. Dr Fazekas was involved in the study planning and has done together with Drs Enzinger and Schmidt the analysis of all MRI scans; this group was mainly involved in the statistical analysis of the MRI data. Drs Martus, Grittner, Holzhausen have taken responsibility for all statistical analysis and for the data structure of the total data bank. Drs Dichgans, Böttcher, Tatlisumak, Tanislav, Jungehulsing, Putaala, Huber, Bodechtel, Lichy, Hennerici, Kaps, Meyer, Kessler have been most active in the recruitment of the patients, drafting the manuscript and significantly influencing the scientific discussion. Dr Heuschmann was involved in drafting the manuscript and influencing the scientific discussion. Dr Norrving chaired the steering and publication committees of sifap, has written parts of the manuscript, and has significantly influenced the scientific discussions. Drs Lackner and Paschke, H. Mascher, Dr Riess have been involved in the laboratory analyses. Dr Kolodny has mostly contributed to the discussion of the Fabry cases. Dr Giese assisted in writing and editing the manuscript. All authors have reviewed, critically revised and approved the final version of the manuscript.The sponsors of the study had no role in the study design, data collection, data analysis, interpretation, writing of the manuscript, or the decision to submit the manuscript for publication. The academic authors had unrestricted access to the derived dataset, and assume full responsibility for the completeness, integrity, and interpretation of the data, as well as writing the study report and the decision to submit for publication.†Listed in Appendix I in the online-only Data Supplement. Jeffrey L. Saver, MD, was guest editor for this article.