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BackgroundOsteochondral lesions are frequently seen in athletes after ankle injuries. At this time, osteochondral autologous transplantation (OATS, mosaicplasty) is the only surgical treatment that replaces the entire osteochondral unit in symptomatic lesions.PurposeTo evaluate the clinical and radiological midterm to long-term outcome of ankles treated with knee-to-ankle mosaicplasty.Study DesignCase series; Level of evidence, 4.MethodsClinical evaluation consisted of patient satisfaction, pain evaluation (visual analog scale [VAS]), American Orthopaedic Foot and Ankle Society (AOFAS) ankle score, sports activity score, range of motion, the radiological evaluation of magnetic resonance imaging (MRI), and single photon emission computed tomography–computed tomography (SPECT-CT) analysis of both the ankle and the knee joint.ResultsTwelve of 21 patients (mean age, 43 years; male, 8; female, 4) were available for latest follow-up (mean, 72 months). At follow-up, patients reported a satisfaction rate of good to excellent in 92% (n 5 11) and poor in 8% (n 5 1). The average VAS pain score was 3.9 (preoperative, 5.9; P 5 .02), AOFAS ankle score significantly increased from 45.9 to 80.2 points (P< .0001), sports activity score remained significantly decreased with 1.25 (preinjury level, 2.3; P 5 .035), and ankle dorsiflexion was significantly reduced (P 5 .003). Knee pain was reported in 6 patients (50%). Radiologically, recurrent lesions were found in 10 of 10 cases (100%) and some degree of cartilage degeneration and discontinuity of the subchondral bone plate in 100%.ConclusionIndications for mosaicplasty with a plug transfer from the knee to the talus must be considered carefully, as at midterm, moderate outcome and considerable donor-site morbidity may be found.

Eine 39-jährige Patientin wurde vom Hausarzt in die Hypertoniesprechstunde überwiesen mit einer kürzlich diagnostizierten therapieresistenten arteriellen Hypertonie. Bei anamestischen Hinweisen für ein Phäochromozytom haben wir dieses mittels erhöhten Metanephrinen und Computertomographie nachgewiesen und operativ entfernen lassen.

Introduction: Magnetic resonance imaging (MRI) of soft tissues after total hip arthroplasty is of clinical interest for the diagnosis of various pathologies that are usually invisible with other imaging modalities. As a result, considerable effort has been put into the development of metal artifact reduction MRI strategies, such as slice encoding for metal artifact correction (SEMAC). Generally, the degree of metal artifact reduction with SEMAC directly relates to the overall time spent for acquisition, but there is no specific consensus about the most efficient sequence setup depending on the implant material. The aim of this article is to suggest material-tailored SEMAC protocol settings. Materials and Methods: Five of the most common total hip prostheses (1. Revision prosthesis (S-Rom), 2. Titanium alloy, 3. Muller type (CoNiCRMo alloy), 4. Old Charnley prosthesis (Exeter/Stryker), 5. MS-30 stem (stainless-steel)) were scanned on a 1.5 T MRI clinical scanner with a SEMAC sequence with a range of artifact-resolving slice encoding steps (SES: 2 – 23) along the slice direction (yielding a total variable scan time ranging from 1 to 10 min). The reduction of the artifact volume in comparison with maximal artifact suppression was evaluated both quantitatively and qualitatively in order to establish a recommended number of steps for each case. Results: The number of SES that reduced the artifact volume below approximately 300 mm3 ranged from 3 to 13, depending on the material. Our results showed that although 3 SES steps can be sufficient for artifact reduction for titanium prostheses, at least 11 SES should be used for prostheses made of materials such as certain alloys of stainless steel. Conclusion: Tailoring SES to the implant material and to the desired degree of metal artifact reduction represents a simple tool for workflow optimization of SEMAC imaging near total hip arthroplasty in a clinical setting. Key Points: • Five of the most common total hip prostheses have been investigated in vitro. • Tailored SEMAC protocols – in terms of scan duration – have been determined. • Tailoring was similar for T1-weighted and inversion recovery SEMAC MRI. • The suggested prosthesis-related SEMAC adaptation shortens clinical scan times. Citation Format: • Deligianni X, Bieri O, Elke R et al. Optimization of Scan Time in MRI for Total Hip Prostheses: SEMAC Tailoring for Prosthetic Implants Containing Different Types of Metals. Fortschr Rontgenstr 2015; 187: 1116 – 1122

Non-invasive or minimal invasive imaging techniques, such as CTA and MRA, are widely used and lead to an increasing number of incidentally diagnosed intracranial aneurysms. This review answers questions regarding pathogenesis, risk of rupture and treatment options. In conclusion, treatment guidelines based on the individual's risk profile are presented.

Zusammenfassung Ein akzessorischer M. soleus ist ein seltener Befund, welcher sich klinisch als eine Weichteilraumforderung dorsomedial des oberen Sprunggelenkes darstellt. Die uberwiegende Anzahl der Patienten ist asymptomatisch. Beschwerden konnen auftreten und sind haufig mit sportlicher Belastung assoziiert. Das MRT zeigt das charakteristischerweise normale Muskelgewebe in abnormaler Lokalisation und dient zur differentialdiagnostischen Abgrenzung vom pathologischen Befund.

Fragestellung: Verbessert ein superparamagnetisches Kontrastmittel (monocrystalline iron oxide nanoparticle, MION) die MR-tomographische Abgrenzbarkeit mikroskopischer Tumorgrenzen im Vergleich zu Gd-DTPA? Methodik: 28 Wistar-Ratten mit stereotaktisch implantiertem Gliom (C6-Gliom) wurden MR-tomographisch und mikroskopisch untersucht. 14 Tiere hiervon wurden nach intravenoser (i.v.) Gabe der MION untersucht [9 Tiere erhielten 179 μmol Fe/kg Korpergewicht (=Dosierung 1), 5 Tiere 893 μmol Fe/kg (=Dosierung 2)]. 14 Tiere wurden zuerst nach i.v. Gabe von Gd-DTPA (0,2 mmol/kg) und anschliesend nach i.v. Gabe der MION untersucht. MR-tomographische und mikroskopische Tumorausdehnungen wurden verglichen. Ergebnisse: Eisenpartikel konnten mikroskopisch in Tumorzellen und im Tumorinterstitium nachgewiesen werden. Nach Gabe der MION in Dosierung 1 war die Ausdehnung des KM-anreichernden Areals in der MRT im Durchschnitt 1,55fach groser als der in der Histologie erkennbare Tumor, bei Dosierung 2 sogar 2,15fach. Im Vergleich mit Gd-DTPA war die KM-anreichernde Flache nach Gabe der MION in Dosierung 1 um den Faktor 1,38 groser, in Dosierung 2 um den Faktor 1,91. Schlusfolgerungen: MION fuhren zu einer intra- und extrazellularen KM-Anreicherung. Die Ausdehnung des KM-anreichernden Areals ist dosisabhangig ausgedehnter als die KM-Anreicherung nach Gd-DTPA Gabe und auch ausgedehnter als die morphologisch nachweisbaren Tumorgrenzen.

Fragestellung: Beeinflussen Form und Grose des praoperativen peritumoralen Hirnodems die Rezidiventwicklung bei malignen supratentoriellen Gliomen? Methodik: Prospektiv wurden 79 Patienten mit einem malignen supratentoriellen Gliom mit einem standardisierten MRT-Protokoll untersucht. MRT-Untersuchungen erfolgten vor der neurochirurgischen Operation, moglichst innerhalb der ersten 3 Tage nach Operation und wahrend der Nachbeobachtungszeit in Abstanden von 2–3 Monaten. Die mediane Nachbeobachtungszeit betrug 11 Monate. Die initiale praoperative Odemkonfiguration auf den T2-gewichteten MRT-Aufnahmen wurde mit der Rezidivtumorkonfiguration auf den Kontrastmittel verstarkten T1-gewichteten Aufnahmen verglichen. Ergebnisse: 47 Patienten entwickelten wahrend der Nachbeobachtungszeit ein Rezidiv. Die Konfiguration des Rezidivtumors imitierte in 35/47 Patienten (75%) die initiale praoperative Odemkonfiguration. Bei 11/47 Patienten entwickelte sich ein lokales und bei einem Patienten ein multilokales Rezidiv. Schlusfolgerungen: Die praoperative Tumorodemkonfiguration im T2-gewichteten MRT-Bild korreliert mit der Rezidivtumorausdehnung. Zukunftige Therapiestudien sollten daher die Ausdehnung des initalen praoperativen Odems als zusatzlichen prognostischen Faktor mitberucksichigen.

AIM Serial observations of acute ischaemic cerebral infarcts by MRI in order to define signal patterns, contrast uptake, oedema and secondary haemorrhage over a period of three months. METHODS Prospective serial examinations of 34 patients with acute cerebral ischaemia who were examined during the first 48 hours, on days 3 or 4, 7, 14, 21, 28 and after three months by MRI (spin echo TR/TE 2200/100/20, 500/20, +/- Gd). RESULTS T2 weighted spin echo sequences showed the highest sensitivity (88%) during the first 8 hours of cerebral ischaemia when compared with other spin echo sequences. Parenchymal contrast enhancement showed a distinct peak during the second and third weeks. The use of contrast did not improve diagnosis of an infarct during any stage. 87% of lesions showed haemorrhage at some stage. Vascular enhancement was observed in 25% of infarcts during the first 24 hours and was still present after three months in 20%. Parenchymal and vascular enhancement, and haemorrhage correlate with the size of the infarct. CONCLUSION Focal cerebral ischaemia produces an abnormality of the blood-brain barrier, oedema and finally necrosis, depending on the severity and duration of the lesion. Haemorrhage in 87% was considerably more common than has been described previously. Vascular enhancement is not an early sign of an infarct, contrary to what has been described in the literature.

Background Isolated unilateral corneal anaesthesia represents a very rare clinical entity. The underlying cause may be a hypoplasia of the trigeminal nerve. History and clinical findings A 7 year old otherwise healthy boy presented with mixed conjunctival injection of the left eye, fluorescein-positive punctuate epithelial keratopathy of the cornea and a central corneal ulcer OS. History revealed intermittent, painless redness of the left eye since the age of 4. Trigeminal defects caused by trauma or infection could be ruled out. Tyndall's phenomena was positive. There was no corneal sensitivity on the left side and facial sensitivity was reduced in all branches of the trigeminal nerve. All other ophthalmologic examination results were normal. Magnetic resonance tomography showed a hypoplastic left trigeminal nerve. Mesenchymal syndromes could be ruled out by neuropediatric examination. Therapy and clinical course Treatment with prednisolone and antibiotic ointment and eye patching were performed. The ulcer healed completely and artificial tear substitution was given for prophylaxis. Follow-up examinations after 4 and 6 years showed no signs of inflammation. Biomicroscopy showed only mild fluorescein-positive corneal epitheliopathy. Conclusions In cases with painless intermittent keratoconjunctivitis, sometimes associated with corneal ulceration, in early childhood, one should consider acquired or congenital trigeminal anaesthesia. This condition requires life-long corneal ulcer prophylaxis and regular ophthalmologic exams.

A 1-year-old girl presented with symptoms of nausea and vomiting, torticollis and paralysis of abducens and facial nerve. MR examination showed on Tl-weighted images a slightly hypointense mass lesion in the right cerebellar hemisphere and a moderately high signal on T2-weighted images, with parallel linear striations on the surface of the lesion. Administration of Gd-DTPA revealed an inhomogeneous, but marked enhancement of the lesion, suggesting the diagnosis of a posterior fossa neoplasm. A subtotal resection was performed. Histologic examination resulted in the diagnosis of Lhermitte-Duclos disease (LDD) (dysplastic gangliocytoma of the cerebellum). Short-term postoperative follow-up MRI showed slight but steady progression of the lesion. Review of literature revealed that this is a unique case of histologically proven LDD in a child showing contrast enhancement after administration of Gd-DTPA and lesion progression within a short postoperative interval.

Ziel der vorliegenden Studie war es, den Stellenwert der CT-Angiographie (CTA) bei der Diagnose von Dissektionen der A. carotis interna (ACI) zu ermitteln. Die Befunde der CTA wurden mit Ergebnissen der digitalen Subtraktionsangiographie (DSA) und der cw-Dopplersonographie (cw-DS) verglichen. Wir untersuchten 21 Patienten mit klinischem oder dopplersonographischem Verdacht auf eine ACI-Dissektion. Bei akuter extrakranieller ACI-Dissektion war die Sensitivitat der CTA 100 % (14/14). Eine intrakranielle ACI-Dissektion wurde durch die CTA nicht erfast, da sie auserhalb des Scanbereichs lag. Die in der cw-DS unspezifischen pathologischen Befunde konnten mit der CTA geklart werden. Haufigster Befund in der CTA war eine exzentrische Lumeneinengung und Wandverdickung sowie eine spitzauslaufende Verschmachtigung (sog. tapering) in der dreidimensionalen (3D-) Rekonstruktion. Die CTA ist bei akuter extrakranieller Karotisdissektion eine verlasliche und wenig invasive Untersuchungsmethode. Vergleichende Studien mit CTA, Duplexsonographie und Magnetresonanztomographie (MRT) sollten noch durchgefuhrt werden.

PURPOSE: Radiation protection is a major issue since the implementation of MSCT technology and its widespread indication for the detection of various diseases. In a European-wide trial (SECT) meta-analyses of imaging alternatives to CT have been initiated. This paper focuses on the diagnostic performance of transthoracic ultrasound (TUS) for the diagnosis of pulmonary embolism (PE) (5 studies, 652 patients). MATERIALS AND METHODS: Medical literature (from 1990 to 2006) in PubMed and EMBASE databases was searched for articles on studies that used TUS as diagnostic tests for PE. Studies were included if they reported the positive and negative rates of PE diagnoses from TUS compared with the rates of PE in CT, MRI or a combination of diagnostic tests. Two readers assessed the quality of the studies. RESULTS: Pooled sensitivity and specificity of TUS for PE were 80 % (95 % CI: 75 %, 83 %) and 93 % (95 % CI: 89 %, 96 %), respectively. CONCLUSION: In the time of MSCT, TUS is an imaging modality that is no longer part of recent diagnostic algorithms for the diagnosis of PE. Considering the increasing number of requested CT examinations and therefore increasing collective radiation dose, this meta-analysis shows that TUS is a diagnostic alternative for special clinical settings in the work-up of suspected PE that seems to have fallen into oblivion.

A 39-year-old woman was referred to our hypertension clinic with refractory hypertension. The patient history gave certain clues for pheochromocytoma. The diagnosis was proven with elevated metanephrines and computer tomography. The tumor was surgically removed.

Ziele: Strahlenschutz ist einer der wichtigsten Streitpunkte seit der Einfuhrung der MSCT Technologie. In einem europaweiten Projekt („safety and efficacy in CT“ – SECT) wurden Metaanalysen initiiert uber die diagnostische Effizienz des CT und uber Alternativen. Diese Studie hat das Ziel der Durchfuhrung einer Metaanalyse zur Evaluierung der diagnostischen Effizienz des TUS in der Diagnostik der Lungenembolie. (5 Studien, 652 Patienten). Methode: Die medizinische Literatur wurde von 1990–2007 in PubMed, Medline und Cochrane Library Datenbanken nach Studien durchsucht, die TUS in der Diagnostik der Lungenembolie benutzten. Prospektive und retrospektive Studien wurden eingeschlossen, wenn sie separat die Rate an richtig-positiven, richtig-negativen, falsch-positiven und falsch-negativen Diagnosen des TUS mit den positiven und negativen Raten im CT, MRT oder einer Testkombination verglichen. Zwei Reader beurteilten die Qualitat der Studien Ergebnis: Die gepoolte Sensitivitat und Spezifitat des TUS zur Diagnostik der Lungenembolie war 80% (95% KI: 75%, 83%) und 93% (95% KI: 89%, 96%). Schlussfolgerung: Im Zeitalter des MSCT ist TUS eine Bildgebung, die nicht mehr Teil aktueller diagnostischer Algorithmen zur Lungenemboliediagnostik ist. Unter Berucksichtigung einer steigenden Anzahl CT-Untersuchungen und daher steigender kollektiver Dosisbelastung zeigt diese Metaanalyse, dass in speziellen klinischen Situationen diagnostische Alternativen in der Bildgebung der Lungenembolie existieren. Korrespondierender Autor: Niemann T Universitatsspital Basel, Radiologie, Petergraben 4, 4031, Basel E-Mail: niemannt@uhbs.ch

As definition, a "kissing" osteochondroma is a typical new bony formation with erosion on the adjacent paired bone, provoked by pressure of the outgrowth. Further diagnostics for incidentally diagnosed solitary osteochondroma should be performed only in cases where malignant transformation is suspected.

To analyze factors with impact on the functional outcome for patients with surgically treated intramedullary spinal cord tumors (IMSCT) and to point out characteristics of the different histological entities. Neurosurgical Department, University of Essen, Germany. Between 1990 and 2000, a consecutive series of 78 patients were referred to our institution and underwent surgical treatment. There were 46 (59%) male and 32 (41%) female patients. Mean age was 43.3 years. Functional outcome was analyzed depending on histological features, age, tumor localization and the extension of involved spinal segments. The mean follow-up period was 34.4 months. Operative removal of the IMSCT was performed under standard microsurgical conditions with intraoperative monitoring of somatosensory-evoked potentials (SSEP). The most frequently involved localization was the cervical and cervicothoracic region (55%) followed by the thoracic region (32%) and the medullar conus (13%). The most frequent IMSCTs were neuroepithelial tumors in 44 patients (56.5%) including 32 patients with ependymomas, 15 astrocytomas, and two lesions without further histological classification. Non-neuroepithelial tumors included 10 metastases, nine cavernomas, eight hemangioblastomas, one dermoidal cyst and one enterogenetic cyst. Complete tumor removal was achieved in 65 cases (83.3%) and subtotal resection in nine cases. In four cases a biopsy was performed only. The overall postoperative neurological state was improved or unchanged in 51 patients (65.4%) and worsened in 27 patients (34.6%). A favorable functional outcome was observed in 94.1% of patients with vascular tumors, in 61.3% of patients with low-grade neuroepithelial tumors and in 53.3% of patients with malignant tumors. The strongest predicting factor of functional outcome was the preoperative neurological condition beyond the histological differentiation of the IMSCT. Although there was no outcome difference with respect to the age and tumor extension, thoracically located IMSCTs proved to harbor an increased risk of postoperative surgical morbidity.

Increased sarcolemmal permeability has been implicated as a major pathological event in muscular dystrophies. In our study, we evaluated whether damaged muscle fibres can be specifically targeted using albumin as a carrier. We tagged human serum albumin (HSA) with Gadolinium (Gd) and systemically applied this compound (Gd-DTPA-HSA) to wildtype and dystrophin-deficient mdx mice. We performed magnetic resonance imaging before and after intravenous administration of Gd-DTPA-HSA and found localised signal enhancement only in mdx skeletal muscle. We also examined skeletal muscle after contrast enhanced magnetic resonance imaging using anti-human albumin antibodies and demonstrated intracellular accumulation of Gd-DTPA-HSA in clusters of damaged mdx muscle fibres. Comparison of magnetic resonance imaging and histological data emphasised the value of contrast agent enhanced magnetic resonance imaging for the in vivo assessment of fibre damage in muscular dystrophies. Furthermore, our data provide evidence that albumin can be used as a carrier to target covalently bound molecules to degenerating muscle fibres.

Spontaneous intracranial hypotension (SIH) is an uncommon condition caused by cerebrospinal fluid leakage. We report of a 29-year-old woman with typical symptoms in whom initial cranial MRI and CT were normal . A clinical diagnosis of SIH, but the symptoms did not resolve with conservative therapy or a lumbar epidural blood patch. Repeat MRI revealed (indirect) findings consistent with SIH but failed to directly demonstrate a cerebrospinal fluid fistula. Subsequent CT myelography revealed leakage of contrast medium into the epidural space bilaterally along the nerve roots at C3–7. Following the myelography the patient reported dramatic clinical improvement with complete resolution of symptoms. The adhesive quality of the myelographic contrast medium might have precipitated closure of the meningeal tears. Myelography may be not only of diagnostic value but also therapeutic in SIH.

A 56-year-old woman was admitted to the hospital because of progressive paresis of the left arm. Clinical examination revealed upper brachial plexus palsy and complete anesthesia and analgesia in segments C5–7. MRI demonstrated diffuse tumorous infiltration of the left brachial plexus with centrifugal growth from the dorsal spinal root of segment C6. Biopsy of the lesion revealed a malignant …

Malignant tumors often show an increased uptake and metabolism of plasma proteins, especially albumin.Determine whether the accumulation of low loaded Gd-albumin improves visualization of malignant tumors by MRI.Twelve nude mice with heterotransplanted squamous cell carcinomas were studied. The signal intensity of tumor, blood, liver, kidney and muscle tissue was studied in MR images after application of Gd-albumin during a period of 144 hours. MRI results were histologically correlated after simultaneously injection of Gd- and fluorescein-labeled albumins in 9 nude mice.Although liver and kidney had a maximum increase in signal intensity within 30 minutes, tumors showed a delayed 51% increase in the 24 hours after application. Histologic and fluorescence evaluation demonstrated albumin localization in tumors predominantly in stroma and necroses.Gd-albumin is efficiently accumulated in SCC transplants. MRI with low loaded Gd-albumin may offer relevant opportunities for recognizing tumors sensitive to a therapy with cyostic drug-labeled albumins.

BACKGROUND AND PURPOSE: Aneurysmal rupture during endovascular treatment is one of the most feared complications of endovascular aneurysm therapy. The purpose of this study was to determine the frequency, causes, management, and outcome of aneurysmal rupture that occurred during treatment with Guglielmi detachable coils (GDCs) in an unselected series of patients with ruptured cerebral aneurysms. METHODS: Between July 1997 and December 2000, we treated 164 acutely ruptured cerebral aneurysms with GDCs. All charts were reviewed, and patients with aneurysmal rupture occurring during embolization were identified. RESULTS: Five patients had an intraprocedural aneurysmal rupture. In one patient, rupture was due to guidewire perforation of the wall. In two patients, the microcatheter itself perforated the aneurysm. In another two patients, rupture occurred during placement of the first coil. Endovascular packing was continued in all patients. One patient died as a result of the aneurysmal rupture. No negative long-term effects were observed in the remaining four patients. In summary, we observed intraprocedural aneurysmal rupture in 3% of our patients, with a mortality rate of 20% and no long-term morbidity. CONCLUSION: Aneurysmal rupture during endovascular treatment with GDCs is a rare event; clinical severity may be variable. Embolization of the aneurysm can be continued in most cases, and most patients with treatment-related subarachnoid hemorrhage survive without serious sequelae.

Introduction Magnet resonance imaging (MRI) is the gold-standard of non-invasive diagnostics in OCL of the talus. Single photon emission computed tomography – computed tomography (SPECT-CT) shows additional, high-resolutioned information of osteoblastic (szintigraphic) activity and bony morphology. The study aimed for evaluating the influence of the SPECT-CT on clinical application of the imaging information and decision-making in OCL therapy. Methods MRI and SPECT-CT of 26 patients (average age: 32 y) were analyzed separately by 3 blinded, independent orthopaedic foot and ankle surgeons experienced in treating OCL and working with MRI and SPECT-CT for treatment decision-making. Imaging information was analyzed by using a specified questionnaire. Results By the SPECT-CT, a change in treatment was documented in 46 of 78 decisions (59%) in comparison to the MRI. Following treatment decisions were chosen most often (total decisions: 156): Retrograde drilling: 64 (41.0%); microfracture and antegrade drilling: 28 (17.9%); osteochondral autologous transplantation (mosaicplasty): 23 (14.8%); excision and debridement: 16 (10.3%); physiotherapy: 9 (5.8%); autologous chondrocyte implantation: 5 (3.2%); joint-sacrificing therapy (e.g. joint replacement): 5 (3.2%); cancellous bone grafting: 4 (2.6%); passive conservative therapy (e.g. cast): 1 (0.6%); drug therapy (e.g. hyaluronic acid): 1 (0.6%); refixation: 0 (0%). However, overall distribution of therapies remained unchanged between MRI and SPECT-CT. The questionnaire revealed main differences in imaging interpretation for: subchondral bone plate morphology (17; 65%), subchondral sclerosis (16; 62%), subchondral cysts (11; 42%), and kissing lesions (10; 38%). The area of szintigraphic activity in comparison to bone bruise was found to be smaller in 50% of cases (13) and bigger in 27% (7 cases). Discussion The additional information provided by the SPECT-CT influences the decision-making for the treatment of OCL in the talus significantly. This is due to changed interpretation of subchondral bone plate morphology and subchondral bone activity. No study reported on SPECT-CT in OCL yet. SPECT-CT may become important in diagnostics and treatment decision-making in OCL of the talus.

To investigate whether the margins of microscopic tumors can be delineated better with monocrystalline iron oxide nanoparticles (MION), a superparamagnetic contrast medium, than with Gd-DTPA by magnetic resonance imaging (MRI).MRI and histological examinations were conducted in 28 Wistar rats with sterotactically implanted gliomas (C6 gliomas). Of the 28 animals, 14 were examined after intravenous administration of MION [nine animals received 179 mmol Fe/kg body weight (dose 1), and five, 893 mmol Fe/kg (dose 2)]. The other 14 animals were examined first after i.v. administration of Gd-DTPA (0.2 mmol/kg) and then after i.v. administration of MION. The extent of the tumors as seen on MRI and at histological study were compared.Iron particles were identified microscopically in tumor cells and in the tumoral interstitium. After administration of MION at dose 1, the contrast-enhanced area of tumor was 1.55-fold greater than the extent of tumor identified by histological study, at dose 2,2.15-fold. Compared with Gd-DTPA the area of contrast enhancement was greater by a factor of 1.38 with MION administration at dose 1 and by a factor of 1.91 at dose 2.MION provides intra- and extracellular contrast enhancement. The area of the contrast-enhanced tumor is dose-dependently greater with MION than with Gd-DTPA and also greater than the extent of tumor seen at histological study.

To assess the influence of initial preoperative brain edema in malignant gliomas on regrowth patterns.79 patients with histologically verified supratentorial malignant glioma were prospectively studied by magnetic resonance imaging (MRI) before and every 2-3 months after surgery. The median follow-up time was 11 months. We correlated the configuration of the initial vasogenic edema on T2-weighted images with tumor regrowth patterns on contrast-enhanced T1-weighted images.35/47 tumor regrowths (75%) imitated the initial edema configuration, while 11/47 occurred within the initial tumor bed; in one case tumor recurrence was multilocal.In glioblastoma, tumor regrowth patterns correlate positively with the configuration of the initial vasogenic brain edema. The initial, "presurgical" peritumoral edema should thus be considered when planning further treatment.

Acute ischemia in the complete territory of the carotid or the middle cerebral artery may lead to cerebral edema with raised intracranial pressure and progression to coma and death. Although clinical data suggest benefit for patients undergoing decompressive surgery for massive space occupying hemispheric stroke, little data about the effects of this procedure on morbidity and outcome is available. The experimental data support an early surgical approach. For early and probably most effective treatment of severe, space-occupying cerebral ischemia, the "malignant" character of the brain edema has to be recognized early after onset of vessel occlusion. Hereby magnetic resonance imaging (MRI) may allow to determine the clinical significance of brain edema early after onset, simultaneously allowing to monitor the evolution of ischemia. We performed serial SE-MRI in rats with acute hemispheric infarctions treated by decompressive craniectomy. Focal cerebral ischemia was induced in 36 rats using an endovascular occlusion technique. Decompressive craniectomy was performed 4 and 24 hours after vessel occlusion in groups of 12 animals each. Twelve animals were not treated by decompressive craniectomy (control group). Four, 24, 48, 72 and 168 hours after MCAO all animals were examined with conventional T1- and T2-weighted SE-MRI. Shift of the midline structures and compression of the ventricles were scored. Changes in weight and neurological performance were measured daily. The infarction volume was calculated by triphenyltetrazolium chloride staining 168 hours after MCAO. While mortality in the untreated group was 33.3%, none of the animals treated by a decompressive craniectomy died (mortality 0%). Neurological behaviour, weight loss and infarction volume were significantly better in the animals treated by early decompressive craniectomy (p0.05). Four hours after MCAO all untreated animals showed a massive shift of the midline structures and a massive compression of the ventricles; only 7 of 12 animals treated early by craniectomy showed mild mass effects. Correlation of the histological brain damage with T2-weighted MRI 4 hours after MCAO was poor (r = 0.41); later than 24 hours there was a good correlation (r0.7). Our results suggest that decompressive craniectomy in malignant cerebral ischemia reduces mortality and significantly improves outcome. If performed early after vessel occlusion, it also significantly reduces infarction size. In the acute phase of hemispheric infarction conventional SE-MRI is not sensitive in estimation of infarction size. Later than 24 hours, conventinal SE-MRI proved to be useful in monitoring brain edema and infarction size in this rat model of malignant hemispheric stroke.

Serial observations of acute ischaemic cerebral infarcts by MRI in order to define signal patterns, contrast uptake, oedema and secondary haemorrhage over a period of three months.Prospective serial examinations of 34 patients with acute cerebral ischaemia who were examined during the first 48 hours, on days 3 or 4, 7, 14, 21, 28 and after three months by MRI (spin echo TR/TE 2200/100/20, 500/20, +/- Gd).T2 weighted spin echo sequences showed the highest sensitivity (88%) during the first 8 hours of cerebral ischaemia when compared with other spin echo sequences. Parenchymal contrast enhancement showed a distinct peak during the second and third weeks. The use of contrast did not improve diagnosis of an infarct during any stage. 87% of lesions showed haemorrhage at some stage. Vascular enhancement was observed in 25% of infarcts during the first 24 hours and was still present after three months in 20%. Parenchymal and vascular enhancement, and haemorrhage correlate with the size of the infarct.Focal cerebral ischaemia produces an abnormality of the blood-brain barrier, oedema and finally necrosis, depending on the severity and duration of the lesion. Haemorrhage in 87% was considerably more common than has been described previously. Vascular enhancement is not an early sign of an infarct, contrary to what has been described in the literature.

Isolated unilateral corneal anaesthesia represents a very rare clinical entity. The underlying cause may be a hypoplasia of the trigeminal nerve.A 7 year old otherwise healthy boy presented with mixed conjunctival injection of the left eye, fluorescein-positive punctuate epithelial keratopathy of the cornea and a central corneal ulcer OS. History revealed intermittent, painless redness of the left eye since the age of 4. Trigeminal defects caused by trauma or infection could be ruled out. Tyndall's phenomena was positive. There was no corneal sensitivity on the left side and facial sensitivity was reduced in all branches of the trigeminal nerve. All other ophthalmologic examination results were normal. Magnetic resonance tomography showed a hypoplastic left trigeminal nerve. Mesenchymal syndromes could be ruled out by neuropediatric examination.Treatment with prednisolone and antibiotic ointment and eye patching were performed. The ulcer healed completely and artificial tear substitution was given for prophylaxis. Follow-up examinations after 4 and 6 years showed no signs of inflammation. Biomicroscopy showed only mild fluorescein-positive corneal epitheliopathy.In cases with painless intermittent keratoconjunctivitis, sometimes associated with corneal ulceration, in early childhood, one should consider acquired or congenital trigeminal anaesthesia. This condition requires life-long corneal ulcer prophylaxis and regular ophthalmologic exams.

To evaluate the role of CT angiography (CTA) in the diagnosis of dissection of the internal carotid artery (ICA).In 21 patients who were clinically or sonographically suspected of having a dissection of the ICA, we performed CTA covering the extracranial course of the ICA. Our technique included spiral scanning (Picker PQ 2000), slice thickness 3 mm, index 1.5 mm, pitch factor 1.25, tube voltage 130 kV, amperage 125 mA, i.v. bolus injection of 100 ml nonionic contrast medium, injection rate 4 ml/s and scan delay 15 s. Spiral data were processed using a workstation (Picker Voxel Q) to calculate 3D "angiographic" reconstructions, maximal intensity projections and multiplanar reconstructions. In 20 of the 21 patients transfemoral angiography was performed, and in all patients cw-Doppler ultrasonography of the carotid arteries was performed.Sensitivity of CTA in acute extracranial dissection of the ICA was 100% (14/14). One patient had a pseudoaneurysm of the ICA, two patients had excessive kinking and one patient showed an atheromatous carotid ulcer. DSA could confirm this in all cases. One intracranial ICA dissection, not covered by the scan field, was missed by CTA. CTA source images demonstrated mural thickening and eccentric luminal narrowing in cases of dissection. 3D reconstructions showed tapering of the ICA.CTA is a reliable tool in the diagnosis of ICA dissection. Further studies comparing CTA, MRI and duplex ultrasound are necessary.