A Dessl

University of Innsbruck, Innsbruck, Tyrol, Austria

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Publications (37)65.88 Total impact

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    ABSTRACT: To determine if the position of kissing stents in the distal aorta has any influence on the patency rate. A retrospective review was conducted of 41 patients (22 men; median age 60.8 years, range 44-86) electively treated for atherosclerotic aortoiliac occlusive disease with angioplasty and kissing stents between January 1997 and January 2005. Two patient groups were defined by reviewing postinterventional anteroposterior radiograms: (1) patients in whom the proximal end of the kissing stents overlapped more than half of their angiographic width within the aorta ("crossing" group) and (2) patients in whom the proximal ends of the stents overlapped half of their width or less ("non-crossing" group). At 2 years, the primary and assisted primary patency rates by life-table analysis were 60.8% and 69.4%, respectively, for the 35 patients included in the life-table analysis. There was no significant difference between the 16-patient "crossing" group and the 19-patient "non-crossing" group in terms of the baseline demographic, morphological, and procedural variables. The primary and assisted primary patency rates at 2 years for the "non-crossing" group were significantly higher (94.1% and 100%, respectively) compared to 33.2% and 45.3%, respectively, for the "crossing" group (p=0.01). Failure of kissing stents in the aortic bifurcation may be significantly increased by the overlap of the free proximal stent ends in the distal aorta.
    Journal of Endovascular Therapy 01/2006; 12(6):696-703. · 2.70 Impact Factor
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    ABSTRACT: BACKGROUND: Endoluminal stent graft repair is emerging as a less invasive alternative to conventional open surgery in the management of diseases of the descending thoracic aorta. In this overview we will discuss the current concept of stent graft therapy of various diseases of the thoracic aorta from an interventional radiologist's point of view. METHODS: Since 1996, 84 patients with atherosclerotic aneurysms of the descending thoracic aorta, aortic dissections, acute traumatic ruptures, chronic traumatic aneurysms and penetrating atherosclerotic ulcers underwent endoluminal stent graft repair at our institution. 18 patients presented with life-threatening symptoms and were treated on an emergency basis. All procedures were performed in an angiographic suite with state-of-the-art digital subtraction angiographic equipment. Follow-up was at 1, 3, 6, and 12 months after treatment and yearly thereafter. RESULTS: The primary technical success rate ranged from 78% to 95%, the 30-day mortality rate was 7% if including elective as well as emergency interventions. Endoleaks were the most common procedure-related complications. They occurred at a rate of 11% and had to be treated by extension cuffs or additional endograft segments. Data of our institution are presented in comparison to the current literature. CONCLUSIONS: Stent graft repair of thoracic aortic aneurysms, aortic dissections and related pathologies is a fascinating new technique offering a less invasive treatment option to patients who are unsuitable for surgical repair. For patients at high surgical risk, endovascular stent graft placement can be advocated as standard therapy. GRUNDLAGEN: Die endovaskuläre Implantation von Stent Grafts gewinnt zunehmend Bedeutung als weniger invasive therapeutische Alternative zur konventionellen offenen chirurgischen Versorgung bei Erkrankungen der deszendierenden thorakalen Aorta. In dieser Übersicht diskutieren wir das aktuelle Konzept der endoluminalen Stent-Graft-Therapie verschiedener Pathologien der deszendierenden thorakalen Aorta aus Sicht des interventionellen Radiologen. METHODIK: Seit 1996 behandelten wir insgesamt 84 Patienten mit thorakalen Stent Grafts. Neben atherosklerotischen Aortenaneurysmen wurden akute und chronische Dissektionen, akute traumatische Rupturen, chronische traumatische Aneurysmen und penetrierende Plaques therapiert. Insgesamt 18 Patienten präsentierten sich mit einer akuten lebensbedrohlichen Symptomatik und wurden unter Notfallsbedingungen behandelt. Alle Eingriffe erfolgten in einem Angiographieraum unter Verwendung einer modernen digitalen Subtraktionsangiographie-Einheit. Das Nachsorgeprotokoll umfasste klinische und computertomographische Untersuchungen nach 1, 3, 6 und 12 Monaten sowie anschließende jährliche Kontrolle. ERGEBNISSE: Die primäre technische Erfolgsrate reichte von 78 % bis 95 %, die 30-Tage-Mortalität betrug unter Berücksichtigung sowohl elektiver als auch notfallmäßiger Interventionen 7 %. Endoleaks stellten mit 11 % die häufigste technische Komplikation dar. Ihre Behandlung erforderte die Implantation von Extensionen oder zusätzlicher Prothesensegmente. Die Ergebnisse an unserer Klinik werden vergleichend zur aktuellen Literatur diskutiert. SCHLUSSFOLGERUNGEN: Die endovaskuläre Implantation von Gefäßprothesen bei Aneurysmen der dezendierenden Aorta, aortaler Dissektionen und assozierter Pathologien stellt einen vielversprechenden neuen Therapieansatz dar, der aufgrund der geringeren Invasivität auch Patienten mit Kontraindikationen für ein offen chirurgisches Vorgehen eine Therapieoption bietet. Bereits heute kann das Verfahren für Hochrisikopatienten als Standardtherapie empfohlen werden.
    European Surgery 05/2004; 36(3):145-151. · 0.15 Impact Factor
  • European Surgery-acta Chirurgica Austriaca - EUR SURG. 01/2004; 36(3):145-151.
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    ABSTRACT: to determine medium term technical and clinical success of kissing stents for aortoiliac occlusive disease. retrospective study. twenty-five patients presenting with intermittent claudication (IC) or critical limb ischaemia (CLI) due to aortoiliac disease (41 complex stenoses, 8 occlusions). balloon- or self-expanding kissing stents, with or without predilatation depending upon the nature of the disease, were inserted via bilateral retrograde femoral artery punctures. Clinical examination, ABPI, exercise testing and duplex ultrasound were performed at 1, 3, 6, and 12 months, and then annually. technical success was achieved in 86% segments. All patients with CLI improved and 6 of 7 ulcerated limbs showed complete healing. During follow-up, 7 patients died and two patients required major amputation at 7 and 8 months. The primary assisted patency rate was 94, 91 and 65% at 6, 12, and 24 months, respectively. despite acceptable short-term technical and clinical success, as the medium term patency rates are clearly inferior to those of bypass surgery, the kissing stent technique should be reserved for high risk patients with a limited life expectancy.
    European Journal of Vascular and Endovascular Surgery 09/2003; 26(2):161-5. · 2.82 Impact Factor
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    ABSTRACT: The purpose of this study was to compare volume rendering and maximum intensity projection as postprocessing techniques of MR angiography in the detection and characterization of intracranial aneurysms. Three-dimensional time-of-flight MR angiography studies performed in 82 patients were retrospectively evaluated by two independent reviewers who were unaware of digital subtraction angiography findings, the standard of reference. Panoramic maximum-intensity-projection and volume-rendered angiograms were produced from each data set to investigate the presence of underlying aneurysms. Each detected aneurysm was then interactively evaluated with subvolume maximum-intensity-projection and targeted volume-rendering algorithms to evaluate aneurysm morphology and size. Aneurysm detection and characterization were evaluated by means of the receiver operating characteristic analysis, and aneurysm size was evaluated using the limits-of-agreement method. Image quality, aneurysm neck depiction, and vascular delineation were also compared between maximum-intensity-projection and volume-rendered images. The time required for the generation and interpretation of maximum-intensity-projection and volume-rendered images was assessed. Volume rendering tended to improve the diagnostic confidence (A(z) [area under the receiver operating characteristic curve] = 0.95 vs A(z) = 0.90 for maximum intensity projection) and yielded a considerable improvement in sensitivity (89% vs 71% for maximum intensity projection), particularly in the detection of small cerebral aneurysms. Regarding aneurysm morphology, volume rendering performed significantly better than maximum intensity projection in lobulation detection (p < 0.001) and slightly better in neck categorization (p > 0.238). Limits-of-agreement analysis showed a trend toward improved assessment of the aneurysm size by volume rendering (-0.31 +/- 1.62 mm vs -1.27 +/- 2.84 mm by maximum intensity projection). Overall image quality and vascular delineation of involved vessels on volume-rendered images were rated better than that obtained by maximum intensity projections (p < or = 0.007 and p < or = 0.001, respectively). Evaluation of time-of-flight MR angiography data sets was significantly facilitated with volume rendering (p < 0.001). The volume-rendering technique facilitates the evaluation of cerebral time-of-flight MR angiography data sets and allows better detection and more reliable characterization of intracranial aneurysms than does maximum intensity projection.
    American Journal of Roentgenology 02/2003; 180(1):55-64. · 2.90 Impact Factor
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    ABSTRACT: Our objective was to develop and evaluate a non-invasive device for rigid immobilisation during extremity angiography. The patented BodyFix immobilisation device (Medical Intelligence, Schwabmünchen, Germany) consists of a vacuum pump connected to special cushions and a plastic foil that covers the body part to be immobilised. First, the patient's extremity is covered by a thin plastic bag and then wrapped in one of the cushions, placed on the top of the therapy couch, and covered with the plastic foil. The air is evacuated from the cushion under the covering foil by the vacuum pump, resulting a hardening of the cushion and thus immobilisation of the patient's extremity. The rigid immobilisation resulted in a complete absence of motion artefacts in the majority of patients. No pixeling of the images was required in any of the 100 patients vs 32% in the control group. Repetition of series could be avoided in all cases and a substantial increase in the quality of the images was obtained. Setup of the device takes an additional 1-2 min. Vacuum immobilisation allows for comfortable, effective immobilisation during digital subtraction angiography, eliminating motion artefacts. This device has become an indispensable tool in daily clinical routine at our department.
    European Radiology 01/2003; 12(12):2890-4. · 4.34 Impact Factor
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    ABSTRACT: Zusammenfassung Über die interventionelle Behandlung atherosklerotischer Verschlussprozesse in der A. femoropoplitea mit Hilfe des HemobahnTM-Stentgrafts wurden divergente Behandlungsergebnisse mitgeteilt. Von uns wurden nach vorausgegangener PTA femoropoplitealer Verschlussprozesse 26 HemobahnTM-Stentgrafts implantiert. 22 Patienten befanden sich im Stadium II, jeweils 2 im Stadium III und IV. Die primäre technische Erfolgsrate betrug 96%, die sekundäre 100%, der Ausstrom-Index nach Müller-Wiefel betrug im Mittel bei 9,2&#453,8. Knöchel-Armdruck-Indizes und Gehstrecke verbesserten sich signifikant. Die mittlere Nachbeobachtungszeit betrug 310 Tage. Im Verlauf entwickelten 10 Patienten (38%) intimale Hyperplasien an den Stent-Enden. Die primäre Offenheitsrate nach 12 Monaten betrug 62%, die sekundäre 69%, die korrigierte sekundäre Offenheitsrate 100%. Lediglich das "Edge"-Phänomen erwies sich als tendenziell prädiktiv für das HemobahnTM-Versagen (p=0,09). HemobahnTM-Stentgrafts führen somit in der A. femoropoplitea zu unbefriedigenden mittelfristigen primären Offenheitsraten. Ihr gegenwärtiger Einsatz ist deshalb außerhalb von Studien allenfalls in spezifischen Situationen, wie z. B. Gefäßperforation, gerechtfertigt. Summary Conflicting results have been published about the treatment of atherosclerotic lesions in the femoropopliteal artery with Hemobahn stent grafts. We implanted 26 Hemobahnstent grafts after femoropopliteal PTA in 22 patients with Fontaine's stage II and 4 patients with Fontaine's stages III and IV. The primary and secondary technical success rates were 96% and 100%, respectively. The runoff index according to Müller-Wiefel was 9.2&#453.8. ABI and exercise test increased significantly (p&#1040.01). The mean follow-up period was 310 days. Ten patients (38%) developed intimal hyperplasia at the edges of the stent graft. Primary and secondary patency after 12 months was 62% and 69%, respectively, and the corrected secondary patency was 100%. Only the edge phenomenon tended to predict stent failure (p=0.09). Hemobahn stent grafts produce unsatisfactory primary patency rates in the femoropopliteal artery. Outside of studies, its use should therefore be restricted to special situations such as perforation during intervention.
    Gefässchirurgie 01/2003; 8(2):100-105. · 0.24 Impact Factor
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    ABSTRACT: To compare volume rendering (VR) and maximum intensity projection (MIP) as postprocessing techniques of magnetic resonance (MR) angiography for detection and quantification of renal artery stenosis. Twenty-seven patients underwent three-dimensional contrast material-enhanced MR angiography of the renal arteries with a 1.5-T imager. For each renal artery, targeted MIP and VR images were reconstructed in oblique coronal and transverse orientations. For each modality, image generation and evaluation were performed interactively by two independent radiologists blinded to angiographic results. In comparison with digital subtraction angiography (DSA) findings, stenosis quantification and detection by using MIP and VR were evaluated with the use of 50% and 70% cutoff points by using linear regression analysis and 2 x 2 tables. Overall image quality and vascular delineation on MIP and VR images were also compared. All main and accessory renal arteries depicted at DSA were also demonstrated on MIP and VR images. VR performed slightly better than MIP for quantification of stenoses greater than 50% (VR: r(2) = 0.84, P <.001; MIP: r(2) = 0.38, P =.001) and significantly better for severe stenoses (VR: r(2) = 0.83, P <.001; MIP: r(2) = 0.21, P =.1). For detection of stenosis, VR yielded a substantial improvement in positive predictive value (VR: 95% and 90%; MIP: 86% and 68% for stenoses greater than 50% and 70%, respectively). Image quality obtained with VR was not significantly better than that with MIP; however, vascular delineation on VR images was significantly better. The VR technique of renal MR angiography enabled more accurate detection and quantification of renal artery stenosis than did MIP, with significantly improved vascular delineation.
    Radiology 05/2002; 223(2):509-16. · 6.34 Impact Factor
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    ABSTRACT: 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.
    min - Minimally Invasive Neurosurgery 04/2002; 45(1):24-31. · 0.62 Impact Factor
  • Journal of Cardiothoracic and Vascular Anesthesia 01/2002; 15(6):755-7. · 1.45 Impact Factor
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    ABSTRACT: To evaluate blood flow changes inside normally functioning transjugular intrahepatic portosystemic shunts (TIPS), using color Doppler ultrasound (CDUS) and pulsed Doppler ultrasound (PDUS). A total of 72 patients (mean age 54, range 36-78 years) underwent TIPS placement, portal angiography, CDUS and PDUS examinations. Measurements inside the stent were taken at the portal side, at the central part and at the venous end of the TIPS. In well functioning TIPS the mean peak velocity (PV) on the portal side was 37 m/s (range 22-65 cm/s), in the area of the incoming intrahepatic portal branch the mean PV was 59 cm/s (range 40-95 cm/s) and at the side of the incoming hepatic vein the mean PV was 135 cm/s (range 88-220 cm/s). In the punctured hepatic and portal veins the mean PV was 25 cm/s (range 15-30 cm/s) and 18 cm/s (10-22 cm/s), respectively. The flow increase from the portal to the mid part (P less than or = 0.001) and to the venous side was statistically significant (P less than or = 0.001). A velocity gradient between the portal and the venous side of a TIPS is a normal finding caused by branches of the portal and hepatic vein joining the TIPS from the side and it is characteristic of a normally functioning TIPS.
    European Journal of Ultrasound 01/2001; 12(2):131-6.
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    ABSTRACT: The purpose of the study was to evaluate the use of the Vogele-Bale-Hohner (VBH) mouthpiece, which is attached to the patient's upper jaw by negative pressure, for patient-image registration and for tracking the patient's head during image-guided neurosurgery. A dynamic reference frame (DRF) is reproducibly mounted on the mouthpiece. Reference points, optimally distributed and attached to the mouthpiece, are used for registration in the patient's absence on the day before surgery. In the operating room, the mouthpiece and DRF are precisely repositioned using a vacuum, and the patient's anatomical structures are automatically registered to corresponding ones on the image. Experimental studies and clinical experiences in 10 patients confirmed repeated (rigid body) localization accuracy in the range of 0 to 2 mm, throughout the entire surgery despite movements by the patient. Because of its noninvasive, rigid, reliable, and reproducible connection to the patient's head, the VBH vacuum-affixed mouthpiece grants the registration device an accuracy comparable to invasive fiducial markers.
    Journal of Neurosurgery 09/2000; 93(2):208-13. · 3.15 Impact Factor
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    ABSTRACT: Virtual endoscopy was used to plan 10 endoscopic third ventriculostomy procedures in 9 patients suffering from occlusive hydrocephalus due to idiopathic aqueductal stenosis and tumors. The patients were 4 children (4-14 years, mean age: 9 years) and 5 adults (21-38 years, mean age: 29 years). The aim of the study was to preoperatively evaluate the individual intraventricular and vascular endoscopic anatomy at the floor of the third ventricle based on virtual endoscopic images. The virtual views were correlated with the real endoscopic images, intraoperatively obtained by a standard ventriculoscope (Wolf, Knittlingen, Germany) during endoscopic third ventriculostomy procedures. Contrast-medium-enhanced MR images (3D-MPRAGE; Siemens, Germany) were semiautomatically segmented with a surface-rendering technique ('Navigator' software; General Electric Medical, Buc, France) to produce the virtual endoluminal views. The virtual endoscopic images were comparable with the real intraoperative endoscopic view in 8 of 9 patients. Virtual endoscopy can display the position of the basilar artery, the posterior cerebral arteries and the posterior communicating arteries in their relationship to the mammillary bodies and the clivus. Preoperative virtual endoscopy planning can intraoperatively assist the neurosurgeon to find a safe location for third ventriculostomy.
    Pediatric Neurosurgery 03/2000; 32(2):77-82. · 0.42 Impact Factor
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    ABSTRACT: 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.
    min - Minimally Invasive Neurosurgery 10/1999; 42(3):113-7. · 0.62 Impact Factor
  • Otolaryngology Head and Neck Surgery 12/1998; 119(5):536-9. · 1.73 Impact Factor
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    ABSTRACT: Evaluation of high resolution ultrasound to diagnose rupture of the medial head of gastrocnemius muscle in patients with uncharacteristic calf pain. 66 patients with clinically unclear calf pain were examined in a prospective study. 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. High resolution sonography detect minimal lesions of the medial gastrocnemius muscle in patients with clinically uncharacteristic calf pain.
    Ultraschall in der Medizin 11/1998; 19(5):230-3. · 4.12 Impact Factor
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    ABSTRACT: Adamantinoma of the long bones is a rare skeletal tumor and its MR features have seldom been reported. It is difficult to distinguish from other bone lesions (such as osteofibrous dysplasia or osteosarcoma) by means of conventional radiography and CT. MR imaging, however, may be useful in differentiating adamantinoma from such lesions. With this presentation of a typical case, we hope to draw the attention of radiologists to this lesion and contribute information on its MR appearance.
    Acta Radiologica 05/1998; 39(3):276-8. · 1.33 Impact Factor
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    ABSTRACT: 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. 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. 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. Due to its high transfer capacity, the ACOnet is considered a reasonable alternative to the ISDN service.
    RöFo - Fortschritte auf dem Gebiet der R 05/1998; 168(4):352-5. · 2.76 Impact Factor
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    ABSTRACT: Malignant appendix tumours are rare entities. Especially adenocarcinomas, which only appear in about 10% of appendix tumours, are very seldom. Preoperative diagnosis is very difficult due to a lack of typical clinical signs and a clinical appearance mimicking perforated appendicitis. Nevertheless, sonography is able to show indirect signs and therefore it can provide the surgeon with more information for a better operative treatment.
    Ultraschall in der Medizin 05/1998; 19(2):90-1. · 4.12 Impact Factor
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    ABSTRACT: To study the value of the Austrian Academic Computer Network (ACOnet) for teleradiology, 1740 test image data-sets and 620 image data-sets were exchanged between the departments of diagnostic radiology of the Universities of Innsbruck and Graz using the ACOnet service. Data transmission was reliable and fast with an average transfer capacity of 170 kByte/s (range 94-341). During the test phase, no major problems with image transfer occurred. Assuming that problems like security of patient data-sets, data compression and data verification can be solved, the ACOnet service would be a useful additional tool for telemedicine applications throughout Austria and eastern Europe.
    Journal of Telemedicine and Telecare 02/1998; 4 Suppl 1:41-2. · 1.47 Impact Factor