[Differential diagnosis in visual field defects of glaucoma patients]. / Differenzialdiagnose bei glaukomatösen Gesichtsfeldausfällen.

In both cases optic disc neuropathy with perimetry defects and loss of vision is caused by a cerebral tumour. The progression of optic damage was stopped by resection of the tumor in both patients. We recommend the performance of a radiological examination in patients with visual field defects if the intraocular pressure is normal and thus glaucoma may not be the cause of the defects.

Prevalence of neurovascular compression in patients with essential and secondary hypertension.

AIMS: There are discrepant data on the prevalence of vascular compression of the rostral ventrolateral medulla, discussed as a possible cause of essential hypertension, in patients with essential and secondary hypertension. We therefore evaluated the comparative prevalence of neurovascular compression in two large and well defined patient groups with severe essential and secondary hypertension. PATIENTS AND METHODS: 121 patients with long-standing severe (requiring at least three antihypertensive agents for adequate control of blood pressure) essential or secondary hypertension and extensive examination for causes of secondary hypertension were recruited. The presence of neurovascular compression was assessed independently by a neuroradiologist and a neurosurgeon in MRI images for all patients. The subgroup of patients with the highest prevalence of neurovascular compression was identified by CART-analysis. RESULTS: 5 of 121 formerly included patients (4.1%) were excluded for diverging MRI assessments. Neurovascular compression was diagnosed in 50 of 68 patients (73.5%) with essential hypertension and 6 of 48 patients (12.5%) with secondary hypertension. The odds ratio for diagnosis of neurovascular compression in patients with essential hypertension was 19.4 (95%-confidence interval 7.9-47.9) compared to patients with secondary hypertension. CART-analysis identified the highest prevalence of neurovascular compression in patients with severe essential hypertension younger than 67.5 years. CONCLUSIONS: Since successful decompression or implantation of a carotid sinus stimulator in patients eligible for surgery may lead to substantial improvement in blood pressure in patients in whom blood pressure could not be lowered below 140/90 mmHg by antihypertensive treatment alone MRI screening for the presence of neurovascular compression is justified in patients meeting all of the following three criteria: exclusion of secondary hypertension after extensive examination; hypertension uncontrollable with antihypertensive treatment alone, and age younger than 67.5 years.

[Sacral nerve root cysts--a rare cause of bladder dysfunction. Case report and review of the literature]. / Sakrale Nervenwurzelzysten--Seltene Ursache von Blasenfunktionsstörungen. Fallbericht und Literaturübersicht.

INTRODUCTION: Asymptomatic cysts of the sacral nerve roots display a prevalence of 5 % and are occasionally demonstrated by MRI of the spine. Depending on their size and localization, arachnoid cysts may cause sacral or perineal pain, radicular sensomotory symptoms and neurogenic bladder and bowel dysfunction by compression of the nerve roots. CASE REPORT: We report on a case of a recently developed neurogenic bladder dysfunction. MRI of the spine demonstrated two large, liquor-filled cysts of 2.5 and 3 cm diameter, bilaterally localized at the nerve roots S2/3. Neurological and urological examinations confirmed the diagnosis of symptomatic nerve root cysts at the level S2/3, resulting in detrusor areflexia. A microsurgical excision of the cysts ameliorated the patient's pain symptoms. However, the detrusor areflexia did not improve. CONCLUSIONS: Tarlov cysts are predominantly regarded an asymptomatic incidental feature of CT and MRI scans of the spine. The case of our patient, as well as the so far published reports indicate, however, that a Tarlov cyst may cause a variety of neurological and urological symptoms. Nerve root cysts should be seriously considered and not excluded at an early stage, especially when coincident with persistent neurological and urological symptoms.

eLearning in education and advanced training in neuroradiology: introduction of a web-based teaching and learning application.

INTRODUCTION: New information technologies offer the possibility of major improvements in the professional education and advanced training of physicians. The web-based, multimedia teaching and learning application Schoolbook has been created and utilized for neuroradiology. METHODS: Schoolbook is technically based as a content management system and is realized in a LAMP environment. The content is generated with the help of the developed system and stored in a database. The layout is defined by a PHP application, and the webpages are generated from the system. RESULTS: Schoolbook is realized as an authoring tool so that it can be integrated into daily practice. This enables the teacher to autonomously process the content into the web-based application which is used for lectures, seminars and self-study. A multimedia case library is the central building block of Schoolbook for neuroradiology, whereby the learner is provided with original diagnostic and therapeutic data from numerous individual cases. The user can put individual emphasis on key learning points as there are various ways to work with the case histories. Besides the case-based way of teaching and learning, a systematically structured way of dealing with the content is available. CONCLUSION: eLearning offers various opportunities for teaching and learning in academic and scientific as well as in economic contexts. Web-based applications such as Schoolbook may be beneficial not only for basic university education but also for the realization of international educational programmes such as the European Master of Medical Science with a major in neuroradiology.

Basal ganglia calcification and psychosis in 22q11.2 deletion syndrome.

Intracerebral calcifications are a facultative symptom of hypoparathyreoidism in 22q11.2 deletion syndrome (22qDS). We describe a patient with 22qDS, basal ganglia calcification (BGC) and psychotic symptoms and discuss the etiological connection of BGC with psychiatric symptoms. Future work needs to determine the prevalence of BGC in 22qDS and psychiatric disorders.

[Surveillance of invasive mold infections in lung transplant recipients: effect of antimycotic prophylaxis with itraconazole and voriconazole]. / Surveillance invasiver Fadenpilzmykosen in lungentransplantierten Patienten: Effekt antimykotischer Prophylaxe mit Itraconazol und Voriconazol.

Between January 2002 and December 2003 all 157 patients (pts) that underwent lung transplantation (LTx) at our institution were prospectively screened for invasive aspergillosis (IA) during their perioperative hospital stay. Patients were regarded as IA positive, if they met the EORTC criteria for 'probable' or 'proven' IA. Records of pts were screened retrospectively for antimycotic prophylaxis. Eight of the 157 pts developed 'probable' or 'proven' IA (5.1%) within 17 +/- 10 days after LTx. This was associated with a 14-fold increased mortality compared with all pts without aspergillosis (P < 0.01, OR 13.8, CI(95%) 2.5-82). Preoperative colonization with Aspergillus was a significant risk factor for IA (P < 0.001, OR 21.9, CI(95%) 4.9-97). We switched our prophylactic strategies to the primary administration of voriconazole in high risk pts (pre-LTx colonization) starting in December 2002. Six pts (6%) of 101 pts receiving itraconazole for antimycotic prophylaxis beginning at postoperative day (POD) one developed IA, of which three pts showed cerebral aspergillosis. One pt (5%) of 18 pts receiving voriconazole prophylaxis developed IA, while 10 pts showed pretransplant colonization with Aspergillus species. Thirty-eight pts received itraconazole prophylaxis at a later time point (>POD 14). By switching our prophylactic strategy to the use of voriconazole in high risk pts, we have decreased the incidence of IA from 8% (six of 75) in 2002 to 2% (two of 82) in 2003. This study shows a high incidence of IA during the very early postoperative course after LTx of 5%. This is associated with a significantly increased risk for mortality. Voriconazole prophylaxis appears to be superior to itraconazole, especially in high risk pts with pretransplant Aspergillus colonization.

Diagnostic value of the fast-FLAIR sequence in MR imaging of intracranial tumors.

The aim of this study was to quantify imaging characteristics of fast fluid-attenuated inversion recovery (FLAIR) sequence in brain tumors compared with T1-postcontrast- and T2-sequences. Fast-FLAIR-, T2 fast spin echo (FSE)-, and T1 SE postcontrast images of 74 patients with intracranial neoplasms were analyzed. Four neuroradiologists rated signal intensity and inhomogeneity of the tumor, rendering of cystic parts, demarcation of the tumor vs brain, of the tumor vs edema and of brain vs edema, as well as the presence of motion and of other artifacts. Data analysis was performed for histologically proven astrocytomas, glioblastomas, and meningiomas, for tumors with poor contrast enhancement, and for all patients pooled. Only for tumors with poor contrast enhancement (n = 12) did fast FLAIR provide additional information about the lesion. In these cases, signal intensity, demarcation of the tumor vs brain, and differentiation of the tumor vs edema were best using fast FLAIR. In all cases, rendering of the tumor's inner structure was poor. For all other tumor types, fast FLAIR did not give clinically relevant information, the only exception being a better demarcation of the edema from brain tissue. Artifacts rarely interfered with evaluation of fast-FLAIR images. Thus, fast FLAIR cannot replace T2-weighted series. It provides additional information only in tumors with poor contrast enhancement. It is helpful for defining the exact extent of the edema of any tumor but gives little information about their inner structure.

Xenon inhalation increases airway pressure in ventilated patients.

BACKGROUND: The inert gas xenon, known as an anaesthetic for nearly 50 years, is also used as a contrast agent during computerised tomography (CT)-scanning. As xenon has a higher density and viscosity than air, xenon inhalation may increase airway resistance. METHODS: In a retrospective study we investigated the effects of 33% xenon/67% oxygen on airway pressure and cardio-respiratory parameters in 37 long-term mechanically ventilated patients undergoing cerebral blood flow (rCBF) measurements by means of stable xenon-enhanced CT. RESULTS: Xenon administration caused a significant increase in peak airway pressure from 31.6+/-8.0 cm H2O to 42.7+/-16.9 cm H2O. This effect was reproducible, did not occur after reduction of inspiratory flow rate by 50% from 0.56+/-0.15 L x s(-1) to 0.28+/-0.08 L x s(-1), and vanished immediately after termination of xenon delivery. CONCLUSION: Due to the higher density and viscosity of this gas mixture, ventilation with xenon/oxygen produces a higher Reynolds' number than oxygen/air when given at the same flow rate. This means that during xenon ventilation the zone of transition from turbulent to laminar gas flow may be located more peripherally (in smaller airways) than during oxygen/air ventilation with a subsequent increase in airway resistance. Our results indicate that xenon inhalation may cause a clinically relevant increase of peak airway pressure in mechanically ventilated patients.

The human mandibular intercondylar angle measured by computed tomography.

In axial computed tomography it is possible to measure the intercondylar angle at the intersection of the longitudinal axes of the condyles. Published values range from 131 to 165 degrees. This angle was determined here in two groups of patients with (n = 22) and without (n = 12) temporomandibular joint dysfunction. A third group of children (n = 12) aged 4-9 years was included to investigate any age-related change in the angle. In the group of healthy individuals, a range of 105 to 165 degrees was found, with a mean intercondylar angle of 139 degrees. In the group with temporomandibular joint dysfunction the mean angle was 143 degrees with a range from 85 to 170 degrees. No statistically significant relation could be shown between intercondylar angle and joint dysfunction. In the group of children the mean angle was 138 degrees with values ranging from 90 to 180 degrees. No significant differences could be demonstrated among the groups. The absolute value of the intercondylar angle seems to be independent of factors such as sex, age and functional disorders of the joint.

Infiltration of the central nervous system by a granulosa cell tumor immunostained by antibodies against inhibin.

Involvement of the CNS by a granulosa cell tumor of the ovary is rare. We describe a patient with leptomeningeal and cerebral cortex infiltration by this tumor. The diagnosis was confirmed by CSF cytology and immunocytochemistry using monoclonal antibodies against human inhibin.

Factors influencing morbidity and mortality after cranial meningioma surgery--a multivariate analysis.

In a retrospective analysis 385 patients with a histologically defined cranial meningioma were studied to analyze the impact of characteristic factors on morbidity and mortality after modern cranial meningioma surgery. Mortality was 4.2% one month and 7.3% six months after operation. 15.6% of the patients stayed more than one month in the hospital (defined as criteria of operative morbidity). Age, poor preoperative clinical condition (ASA score), intra- and postoperative bleeding and CSF disturbances were significantly associated with a subsequent decrease of quality of life. First symptoms like intracranial hypertension, seizures, aphasia and hemiparesis were correlated with an increase of postoperative Karnowsky index. Postoperative quality of life decreased in patients with optic and other cranial nerve disturbances significantly. Tumour size, location (exception: medial sphenoid wing) and histological diagnosis did not influence surgical outcome. This information may be useful in management decisions regarding asymptomatic meningiomas in elderly and high risk patients.

[Stable xenon computed tomography. Methodology and clinical application]. / Die Stable-Xenon-Computertomographie. Methodik und klinische Anwendung.

According to the principle of the dynamic computed tomography, stable xenon computed tomography allows measurement of the increase in density caused by xenon in the brain tissue. During a period of about 4 min a patient inhales a mixture of xenon (33%) and oxygen. By means of a special software, this method can be used to calculate flowmaps and to determine the local cerebral blood flow in a 1 cm x 1 cm areal. Stable xenon computed tomography is used mainly for cerebral blood flow measurements in patients with cerebrovascular diseases and also allows calculation of cerebral reserve capacity following stimulation of blood flow by the carboanhydrase inhibitor acetazolamide (Diamox).

Impact of hard-copy size on observer performance in digital chest radiography.

To determine the impact of reduced hard-copy size on diagnostic performance of digital radiography, screen-film chest radiographs were compared with isodose digital storage phosphor radiographs in the detection of simulated nodules, fine pulmonary lines, and micronodular opacities superimposed on the chests of 10 healthy volunteers. Digital radiographs were laser-printed in a full-size conventional format and in image lengths of two-thirds, one-half, and five-elevenths of the conventional format. Eighteen thousand observations by eight radiologists were analyzed by use of receiver operating characteristics. The detectability of lines and micronodular opacities decreased with declining image format size. In the detection of micronodular opacities, only the nearly full-size digital images were equivalent to conventional images. In the detection of linear opacities, reduction of image length by one-half or more reduced performance (analysis of variance, P less than .05). Only for the detection of nodules was no major difference found.

[The visibility of a central venous catheter using digital luminescence radiography in intensive care radiology]. / Erkennbarkeit zentralvenöser Katheter bei Einsatz der digitalen Lumineszenzradiographie in der intensivmedizinischen Radiologie.

The aim of the following study was to assess the impact of dose alterations on the detection of catheters. We compared the performance of well-exposed conventional and digital portable chest radiographs in the detection of thin catheters and tested the influences of dose alterations. Portable chest radiographs of 20 patients were obtained with conventional film/screen (FR) and with storage phosphors at 50% (SRL), 100% (SRN), and 250% (SRH) of the conventionally required exposure dose. The region of the mediastinum was subdivided into an average of 18 fields, 50% of which were superimposed with thin catheter segments. ROC analysis of 11,600 observations by 8 readers found only SRH equivalent to FR in catheter visualisation. Performance decreased significantly with SRN and SRL. Detection of low contrast catheters was found to be significantly decreased in storage phosphor radiographs obtained with standard exposure dose. A dose reduction is not feasible with current equipment if performance equivalent to conventional radiography is to be achieved.

Effects of 33% stable xenon/O2 mixture on somatosensory evoked potentials.

The influences of 30% stable xenon/O2 mixture on somatosensory evoked potentials were investigated in 8 patients with and without Diamox application. Changes of the amplitude of the primary cortical response occurred frequently and correlated well with the psychotropical effect of xenon. They usually normalized within 2 to 3 minutes after ending xenon inhalation. There were no significant changes of the latency of the N20.

[The foramen of Monro--blockage caused by a giant aneurysm of the basilar artery. A case report and review of the literature]. / Foramen Monroi--Blockade durch ein Riesenaneurysma der Arteria basilaris. Fallbeschreibung und Literaturübersicht.

A case of a giant aneurysma of the basilar artery bifurcation with occlusive hydrocephalus due to bilateral foramen of Monro occlusion is reported. The patient presented with progressive neurological deterioration which led to computerized tomography examination and implantation of a ventricular shunt as an emergency procedure. After the patient had recovered to a certain extent, four-vessel angiography was performed that demonstrated a giant basilar tip aneurysm. As the posterior communicating, the posterior cerebral as well as the superior cerebellar arteries originated from the aneurysm sac direct surgical attack as well as endovascular treatment was considered to be impossible. A permanent biventricular-abdominal shunt system was implanted and the patient was discharged. Three weeks later the patient was readmitted comatose after he had suffered a massive subarachnoid hemorrhage from which he finally died. The clinical and radiological signs, the differential-diagnostic considerations as well as the few cases of foramen of Monro occlusion by a giant basilar artery tip aneurysm, presented in the literature so far, are discussed.

[The effect of acetazolamide-induced, endogenous volume stress of the cerebrospinal system on intracranial pressure. Diamox--effect on intracranial pressure]. / Die Wirkung der Acetazolamid-induzierten, endogenen Volumenbelastung des zerebrospinalen Systems auf den intrakraniellen Druck. DIAMOX--Wirkung auf den intrakraniellen Druck (ICP).

In 16 patients with possible disturbed CSF circulation longterm recording of intracranial pressure (ICP) was performed. In 9 of the 16 patients the disorder became evident after the application of an exogenous volume-pressure testing procedure. This procedure enabled a classification into a group I--disturbed CSF circulation (8 patients)--and another group II--normal CSF circulation (8 patients). During a routine Xenon-CT-CBF study all patients of both groups were given to 1 g acetazolamide (DIAMOX) intravenously. Before, during and after the administration of DIAMOX the epidural ICP was continuously measured. An increase in ICP was monitored in all patients. In group I the average initial ICP was 13.6 +/- 7.6 mmHg. The maximum ICP was reached within a time interval of 13.1 +/- 4.5 min after DIAMOX administration. At this time the mean ICP was 36.4 +/- 19.2 mmHg (p less than 0.01). The average initial ICP in group II was 6.3 +/- 4.2 mmHg. The maximum ICP was reached within a time interval of 13.6 +/- 1.1 min. At this time the mean ICP was 11.9 +/- 4.8 mmHg (p less than 0.01). In respect to the maximum ICP both groups were significantly different (p less than 0.01). Despite a considerably rising ICP up to values of about 50 to 70 mmHg in several patients of group I only 1 patient complained of being sick. Presumingly, an ICP elevation caused by vasodilatation would be better tolerated than ICP elevations due to other causes.