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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.

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.

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.

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.

Objective: To evaluate blood flow changes inside normally functioning transjugular intrahepatic portosystemic shunts (TIPS), using color Doppler ultrasound (CDUS) and pulsed Doppler ultrasound (PDUS). Methods: 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. Results: 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≤0.001) and to the venous side was statistically significant (P≤0.001). Conclusion: 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.

Die funktionelle Untersuchung mittels des Score nach Constant und Murley ergab durchschnittlich 97 von 100 moglichen Punkten (Minimum 72, Maximum 100) in beiden Gruppen, sowohl nach konservativer als auch nach operativer Therapie. Bei der Nachuntersuchung wiesen 9 von 10 konservativ (90%) behandelten Patienten nach drittgradiger AC-Luxation ein positives Klaviertastenphanomen und eine vermehrte Horizontalverschieblichkeit der Klavikula im Gegensatz zu 18 (44%) von 41 operierten Patienten auf (p

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

Objectives: to determine medium term technical and clinical success of kissing stents for aortoiliac occlusive disease. Design: retrospective study. Subjects: twenty-five patients presenting with intermittent claudication (IC) or critical limb ischaemia (CLI) due to aortoiliac disease (41 complex stenoses, 8 occlusions). Methods: 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. Results: 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. Conclusions: 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. Eur J Vasc Endovasc Surg 26 , 161-165 (2003)

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 (p0.001) and slightly better in neck categorization (p0.238). 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 (por = 0.007 and por = 0.001, respectively). Evaluation of time-of-flight MR angiography data sets was significantly facilitated with volume rendering (p0.001).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.

The aim of this study was to compare between volume rendering (VR) and maximum intensity projection (MIP) as post processing techniques of MR angiography in detection and characterization of intracranial aneurysms.

CONTRAST ECHOCARDIOGRAPHY (CE) is a valuable diagnostic tool that is being used increasingly for the detection of intracardiac and intrathoracic extracardiac shunts.1-4 CE should be a part of the investigation of patients with penetrating chest injury as a first-line screening test for arteriovenous malformations.5,6 CE is commonly employed in evaluating intracardiac shunts, whereas pulmonary angiography is considered the gold standard in evaluating and localizing extracardiac shunts,1,5 especially in diagnosing pulmonary arteriovenous malformations and traumatic pulmonary arteriovenous fistulae. A case of a traumatic pulmonary arteriovenous fistula diagnosed by transesophageal CE and confirmed by pulmonary angiography is presented. This case shows the efficacy of transesophageal CE with the aid of a pulmonary artery catheter to differentiate between intracardiac and extracardiac shunts. To some extent, CE also helped to localize the shunt lesion and estimate the amount of shunt.

To evaluate the feasibility and safety of endovascular stent-graft placement in treating Stanford type B aortic dissection.Seven patients underwent endovascular stent-graft placement for type B aortic dissection. Five patients had acute and two had chronic dissection. In five patients, the proximal entry tear was within 2 cm of the origin of the left subclavian artery, and in two patients it was beyond this site. In three patients, the noncovered proximal portion of the stent-graft was placed across the origin of the left subclavian artery. The efficacy of the procedure was assessed at follow-up studies 3, 6, 12, and 24 months after intervention.The procedure was technically and clinically successful in six patients (86%). The left subclavian artery remained patent in all patients. In two patients with involvement of aortic branches, endovascular stent-graft placement restored adequate blood flow to the compromised branches. One patient was readmitted 1 month later because the dissection extended into the ascending aorta. In all but this patient, closure of the entry tear and thrombosis of the false lumen along the stent-graft were achieved. All false lumina shrank considerably. The mean follow-up time was 14 months (range, 1-25 months).Type B aortic dissections within and beyond 2 cm of the origin of the left subclavian artery can be treated safely and effectively by means of endovascular stent-graft placement.

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.

Background and Study Aims: The aim of the present study was to establish a suitable method for virtual computed tomography (CT) gastroscopy. Patients and Methods: Three-millimeter helical CT scans of a pig stomach were obtained after air insufflation and instillation of diluted diatrizoic acid (Gastrografin), and with double contrast. In addition, three patients with gastric tumors were studied after ingestion of an effervescent agent (Duplotrast, 6 g) and intravenous injection of hyoscine butylbromide (Buscopan, 1 ml). Virtual endoscopy images were computed on a Sun Sparc 20 workstation (128 megabytes of random access memory, four gigabytes of hard disk space), using dedicated software (Navigator, General Electric Medical System Company). The endoscopy sequences were compared with real endoscopic examinations and with anatomical specimens. Results: In the cadaver studies, the best results were obtained with plain air insufflation, whereas virtual CT gastroscopy with diluted contrast and with double contrast showed artifacts simulating polyps, erosions, and flat ulcers. Patient studies showed good correlation with the fiberoptic endoscopy findings, although large amounts of retained gastric fluid substantially reduced the quality of the surface reconstruction. Conclusion: These preliminary results show that virtual CT gastroscopy is able to provide insights into the upper gastrointestinal tract similar to those of fiberoptic endoscopy. However, due to the limited spatial resolution of the CT protocol used, as well as inherent image artifacts associated with the Navigator program's reconstruction algorithm, the form of virtual CT gastroscopy studied was not capable of competing with the imaging quality provided by fiberoptic gastroscopy.

We carried out a cost analysis of a teleradiology system for emergency computerized tomography CT examinations. Teleradiology was implemented by connecting two spiral CT scanners in the University Hospital in Innsbruck and the Regional Hospital in Zwettl. It enabled the remote hospital in Zwettl to get fast and competent reports of emergency CT examinations when there was no specialist radiologist available. In 13 months use for routine night and weekend service, the system proved fast and reliable. During the study period 121 emergency examinations of 116 patients were transmitted from Zwettl to Innsbruck. The fixed costs of teleradiology were for the ISDN connection and amounted to DM230 plus DM696 year rental. The average cost of one emergency CT examination by teleradiology was DM372 range 308-453 . One possible alternative, transporting the films by taxi for reporting elsewhere, was cheaper estimated cost DM156 , but would have been much slower. Another alternative, transporting the patient to the nearest central hospital for scanning, was much more expensive: DM524 by road or DM4667 by helicopter ambulance.

Spinal cord compression due to extradural and subdural haemorrhage is a neurosurgical emergency. Differences in clinical presentation in relation to localisation of the haematoma, value of MRI as a diagnostic tool, surgical treatment, and prognosis were investigated in a retrospective case series of eight patients with extradural (n = four) and subdural (n = four) haematomas. Results of MRI were compared with operative findings and proved to be of high sensitivity in defining the type of bleeding and delineating craniocaudal extension and ventrodorsal location. Surgical treatment by decompressive laminectomy, haematoma evacuation, and postoperative high dose corticosteroids resulted in resolution of symptoms in five patients and improvement in the clinical situation in two patients. One patient with a chronic subdural haematoma had a second operation because of arachnoidal adhesions. One patient presented with a complete cord transection syndrome due to an acute subdural haematoma and remained paraplegic. It is concluded that prompt, reliable, and non-invasive diagnosis by MRI leads to efficient surgical treatment and a favourable outcome in this rare condition.

In their report Alvine et al. [1] published an interesting case of hibernoma in the thigh region, showing the MRI features of this rare lesion with CT and histopathological correlation. We investigated a case of a hibernoma in the retropharyngeal and neck region – a main location for remnants of embryonal brown fat – with somewhat similar MRI features. We can confirm the finding that hibernoma is hypointense to normal subcutaneous fat on non-enhanced T1-weighted images – in fact in our case not only subtle but clear differences in signal intensity were seen. Nevertheless the lesion is clearly hyperintense to normal skeletal muscle. Hyperintensity is marked on T2weighted spin-echo images, and bright but somewhat inhomogeneous enhancement is seen after intravenous gadolinium injection due to the hypervascular nature of the lesion. In contrast to this general agreement we cannot agree with the authors’ belief that this signal behaviour should be a means of differentiating hibernoma from other lipomatous soft tissue lesions. In our experience lipomatous lesions show a high variability in signal intensities. Unfortunately lesions of completely different derivation such as the benign elastofibroma and malignant myxoid liposarcoma may look identical to hibernoma on unenhanced as well as enhanced T1-weighted images. As in other cases MRI differentiation relies mainly on signal homogeneity, distinction of tumour borders or possibly the time course of contrast uptake if dynamic MRI is considered. Apart from the fact that this rare lesion should be included in the differential diagnosis by the skeletal radiologist if a somewhat lipomatous soft tissue lesion is encountered, the value of MRI in our opinion lies mainly in the possibility of clearly delineating the tumour from surrounding neurovascular structures and its far better ability to demonstrate the hypervascular nature of the tumour and the exact tumour extension, which are important in therapeutic intervention.