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AIM Evaluation of high resolution ultrasound to diagnose rupture of the medial head of gastrocnemius muscle in patients with uncharacteristic calf pain. METHOD 66 patients with clinically unclear calf pain were examined in a prospective study. RESULTS Out of 66 patients, 51 showed sonographic criteria of a partial rupture of the medial gastrocnemius head. 47 ruptures were located in musculotendineus transition zone. CONCLUSION High resolution sonography detect minimal lesions of the medial gastrocnemius muscle in patients with clinically uncharacteristic calf pain.

To evaluate the usefulness of virtual endoscopy (VE) in planning neuroendoscopic intraventricular surgeries, the technique was applied in 20 of 22 consecutive procedures. Thirteen endoscopic third ventriculostomies (ETV) in 12 patients, 3 endoscopic colloid cyst removals, 1 third ventricular arachnoidal cyst fenestration, 1 endoscopic ventricul-cysto-cisternostomy (suprasellar arachnoidal cyst), 1 endoscopic tumor biopsy, one third ventricular gross total tumor removal and 2 septostomies at the foramen of Monro due the septal occlusion were performed. Contrast medium-enhanced MR images (3DMPRAGE, Siemens, Germany) were semi-automatically segmented with a surface-rendering technique ("Navigator" software, General Electric Medical, Buc, France) to produce the virtual endoluminal views. Surgery was performed with cerebral ventriculoscopes by Wolf (Richard Wolf, Knittlingen, Germany). VE was feasible in all patients and the virtual endoscopic images were comparable with the real intraventricular views obtained by standard rod lens systems. After contrast medium administration intra- and paraventricular vessels such as the thalamocaudate vein, the septal veins, the basilar artery and its branches (distal BA complex) and the choroid plexus were identified on the virtual endoscopic images. In 8 patients, the additional anatomic information provided by VE profoundly influenced surgical planning. VE provides the neurosurgeon with additional morphological information supporting the planning process of neuroendoscopic intraventricular surgeries, contributing to the safety of the procedures.

We evaluated the usefulness and reliability of intraventricular virtual neuroendoscopy based on a comparative anatomical study. Virtual intraventricular endoscopic images were calculated from 3D magnetic resonance images in five anatomic specimens. Contiguous 1.2 mm slices of the specimen heads were acquired at a 1.5 T MR scanner using a 3D-gradient echo sequence. The images were then transferred to an independent 3D-workstation (Sun Spark 20). After scanning the specimen heads, real endoscopy within the cerebral ventricles of these brains was performed with a standard rod lens system. Comparison between real and virtual endoscopic views of the intraventricular topography was based on the same anatomical reference and landmarks. Acquisition of MR data and virtual image post-processing have been possible in all specimens. The virtual endoscopic images of the ventricles were comparable to the intraventricular views obtained by a standard rod lens system. Virtual intraventricular neuroendoscopy can be employed for planning and simulating neuroendoscopic procedures. It enables the neurosurgeon to simulate the endoscopic procedure within the cerebral ventricles on the basis of the patient's individual anatomy prior to surgery.

PURPOSE To assess the feasibility of image transfer for teleradiologic consultations using the Austrian Academic Computer Network (ACOnet). The ACOnet corresponds between the main universities to a MAN (Metropolitan Area Network) with a transfer rate of 4 Mbps. Its use is free of charge for university institutions. MATERIALS AND METHODS 1740 test image data sets and 620 image data sets for teleradiological consultations were exchanged without annotations between the Departments of Diagnostic Radiology of the universities of Innsbruck and Graz, using the ACOnet. RESULTS Data transmission was reliable and fast with an average transfer capacity of 170.2 kBytes/s (94-341 kBytes/s). There were no major problems with image transfer during the test phase. CONCLUSION Due to its high transfer capacity, the ACOnet is considered a reasonable alternative to the ISDN service.

UNLABELLED The teleradiological connection between the University Hospital in Innsbruck, Tyrol, and the Regional Hospital in Zwettl, Lower Austria, is presented as an example of a routine online connection of two helical CT systems. PURPOSE To establish a practicable and cost-efficient emergency CT service in a remote hospital during night time and on weekends. MATERIAL AND METHODS Online connection of a GE HiSpeed Advantage-Spiral-CT and a GE Prospeed-Spiral-CT via two Sun SPARC 10 work stations and ISDN. RESULTS The transmission of 121 CT data sets from 116 patients revealed a sufficiently fast average transmission time of 15 (6-53) minutes and average transmission costs of DM 9.00 per examination. The system was technically reliable, cost-efficient and practicable in clinical routine application. CONCLUSIONS Teleradiology enables remote hospitals to provide an emergency CT service even if there is no radiological specialist available outside office hours. Thus time-consuming and cost-intensive patient transfers and delay of therapy can be reduced.

Purpose In this article a new method - the Smart-Scan-Technique - for dose reduction during spiral computed tomography is described. This technique allows a dynamical adaptation of the tube current according to the measured local density structure form and absorption values of the object of interest. Its clinical applicability for dose reduction is investigated. In addition, changes in image quality are evaluated. Methods Specially designed, water filled plexiglas-phantoms, an Alderson-Rando phantom, and 20 patients were used to simulate possible measures of patients within the thoracic and abdominal region. For those two regions the dose reduction, the modulation transfer function, and the pixel noise were measured. Results Depending on patient geometry dose reduction up to 20% could be achieved with the Smart-Scan-Technique. This technique also enabled a decrease of the modulation transfer function and an increase of the pixel noise by 8%. Conclusion Relevant dose reductions can be achieved by applying the Smart-Scan-Technique in spiral computed tomography.