[Orbital inflammatory diseases]. / Entzündliche Erkrankungen der Orbita.

CLINICAL/METHODICAL ISSUE: Inflammatory orbital processes on imaging are often misinterpreted as tumors. STANDARD RADIOLOGICAL METHODS: Imaging comprises computed tomography (CT) and magnetic resonance imaging (MRI). ACHIEVEMENTS: Clinical and laboratory data play a crucial role in diagnosing many inflammatory orbital diseases. Radiological imaging provides a supporting but relevant role. PRACTICAL RECOMMENDATIONS: Clinical examination, including specialized ophthalmological examinations, laboratory diagnostics, and MRI are important in the diagnosis of inflammatory orbital diseases.

[Pediatric posterior fossa tumors]. / Infratentorielle Hirntumoren bei Kindern.

CLINICAL ISSUE: Tumors of the posterior fossa account for about 50-55% of brain tumors in childhood. DIAGNOSTIC WORKUP: The most frequent tumor entities are medulloblastomas, pilocytic astrocytomas, ependymomas, diffuse midline gliomas and atypical teratoid-rhabdoid tumors. Neuroradiological differential diagnosis with magnetic resonance imaging (MRI) is of considerable importance for preoperative planning as well as planning of follow-up therapy. PERFORMANCE: Most important findings for differential diagnosis of pediatric posterior fossa tumors are tumor location, patient age and the intratumoral apparent diffusion assessed by diffusion-weighted imaging. ACHIEVEMENTS: Advanced MR techniques like MRI perfusion and MR spectroscopy can be helpful both in the initial differential diagnosis and in tumor surveillance, but exceptional characteristics of certain tumor entities should be kept in mind. PRACTICAL RECOMMENDATIONS: Standard clinical MRI sequences including diffusion-weighted imaging are the main diagnostic tool in evaluating posterior fossa tumors in children. Advanced imaging methods can be helpful, but should never be interpreted separately from conventional MRI sequences.

[Cerebral and spinal cavernomas]. / Zerebrale und spinale Kavernome.

CLINICAL/METHODICAL ISSUE: Cavernous malformations or cavernomas belong to the angiodysplasias. They may be sporadic or familial and cause symptoms (epilepsy) despite the absence of a left-to-right shunt. In addition to intracranial locations, spinal cavernomas are also found. STANDARD RADIOLOGICAL METHODS: Magnetic resonance imaging (MRI) and computed tomography (CT) are used for diagnosis PERFORMANCE: MRI, except for acutely or subacutely hemorrhaged cavernomas, is superior to CT for lesion detection. ACHIEVEMENTS: CT is reserved for acute diagnosis. MRI, especially susceptibility-sensitive gradient echo sequences, can also detect cavernomas without (sub-)acute hemorrhage or calcifications. PRACTICAL RECOMMENDATIONS: MRI is also useful for differentiating the familial form vs. sporadic form. Digital subtraction angiography (DSA) is used for differential diagnosis in rare cases, as cavernomas show no correlate here.

[Autoimmune reactions and paraneoplastic syndromes]. / Autoimmunreaktionen und Paraneoplasien.

CLINICAL ISSUE: Autoimmune disorders of the central nervous system (CNS) are common but are also a heterogeneous group of diseases. The most common form is multiple sclerosis (MS), others are clinically isolated syndrome (CIS), acute demyelinating encephalomyelitis (ADEM) and neuromyelitis optica spectrum disorders (NMOSD). Paraneoplastic syndromes are rare and tumor-associated, they are not induced by direct invasion of tumor tissue but by tumor-associated autoantibodies mostly against specific CNS proteins, e. g. limbic encephalitis and paraneoplastic cerebellar ataxia or degeneration. DIAGNOSTICS, STANDARD RADIOLOGICAL METHODS, PERFORMANCE AND ACHIEVEMENTS: The correct diagnosis of autoimmune and paraneoplastic syndromes can still be challenging. In addition to the patient history, clinical examination and blood as well as cerebrospinal fluid (CSF) tests, magnetic resonance imaging (MRI) is gaining importance in the diagnostics. It is important not only in primary diagnostics but also in follow-up and therapy monitoring, especially in MS with specific therapies to detect therapy complications, such as progressive multifocal leukoencephalopathy as early as possible. In paraneoplastic syndromes MRI can also be an important component in the diagnostics but can also initially be negative and typical signal changes become visible only in follow-up scans. PRACTICAL RECOMMENDATIONS: In paraneoplastic syndromes the correct diagnosis is based on laboratory tests for specific autoantibodies in serum and CSF. TREATMENT: The treatment of autoimmune and paraneoplastic disorders of the CNS ranges from steroids and immunosuppressive agents to plasmapheresis, depending on the specific disorder.

[Agenesis of the corpus callosum]. / Balkenfehlbildungen.

CLINICAL ISSUE: Agenesis of the corpus callosum is reported to have an incidence of about 1:4000 live births. In 30-45% of cases, genetic etiologies can be identified, e. g., 10% chromosomal anomalies and 20-35% genetic syndromes. Environmental factors like fetal alcohol syndrome are also known to be prone to callosal agenesis. Callosal agenesis can be complete or partial and can be isolated or associated with other central nervous system (CNS) anomalies (e. g., cortical developmental disorders, callosal lipoma, intracranial cysts) or extra-CNS anomalies (e. g., eyes, face, cardiovascular). STANDARD RADIOLOGICAL METHODS AND METHODICAL INNOVATIONS: Diagnosis is made using ultrasound, computed tomography (CT) or best with magnetic resonance imaging (MRI). Typical imaging findings in callosal agenesis are colpocephaly, high riding enlarged third ventricle, Texas Longhorn configuration of frontal horns and so-called Probst bundles parasagittal. Diffusion tensor imaging and fiber-tracking, based on diffusion-weighted techniques, can also visualize fiber/tract anomalies in the patients' brains. ASSESSMENT: Clinical correlations of callosal agenesis is difficult in general because of the common association of other CNS malformations. Differential diagnosis of primary complete or partial callosal agenesis are secondary callosal changes, e. g. vascular, inflammatory or posttreatment in origin.

[Tumors of the sellar region]. / Tumoren der Sellaregion.

METHODICAL ISSUE: The anatomy of the sellar region is complex and tumors of the sellar region are very variable because they arise from the many different tissue types in the sellar region, ranging from benign to life-threatening. Despite this variety, approximately 80% of sellar region tumors are due to the 5 most common lesions: adenomas, meningiomas, aneurysms, astrocytomas and craniopharyngiomas. STANDARD RADIOLOGICAL METHODS: In addition to clinical and laboratory results, the magnetic resonance imaging (MRI) and computed tomography (CT) results including the exact anatomical position and the proliferation pattern of the lesion are decisive for the diagnosis. The gold standard for diagnostic imaging is multiplanar, thin section, contrast-enhanced MRI with soft tissue contrast. Vessel imaging and CT are complementary modalities in selected cases and often for preoperative planning. METHODICAL INNOVATIONS: Whereas most sellar region tumors can be well visualized with multiplanar, contrast-enhanced MRI, for very small intrapituitary microadenomas dynamic contrast-enhanced T1-weighted sequences can be necessary. Microadenomas can often only be clearly demarcated from the rest of the pituitary tissue due to the different perfusion pattern. Optimized diffusion-weighted images can also be useful for narrowing down the differential diagnoses of sellar region tumors. PERFORMANCE AND ACHIEVEMENTS: Tumors of the sellar region can be subdivided in intrahypophysial and extrahypophysial lesions as well as intrinsic skull base lesions. The most common sellar tumors are adenomas of the pituitary gland, which can be subdivided into microadenoma and macroadenoma and into secretory and non-secretory. PRACTICAL RECOMMENDATIONS: If there is suspicion of a sellar region lesion due to clinical or laboratory results, multiplanar contrast enhanced thin section MRI of the sellar region should be used as the primary imaging modality. The keys to the diagnosis are the precise anatomical location of the lesion and the proliferation pattern. The most common lesions in the sellar region are pituitary gland adenomas, which can be small and often secretory or larger and often non-secretory.

[Intubation and sedation in the endovascular treatment of acute cerebral infarction]. / Intubation und Sedierung bei der endovaskulären Therapie des akuten Hirninfarkts.

In the past complex intracranial treatments demanded intubation and general anesthesia of the patient. With increasing rate of endovascular local treatment of acute stroke more and more neurointerventionalists report that recanalisation techniques can be performed in sedation of the patient without the need of additional intubation. Although prospective studies are lacking retrospective studies have shown that the risk of iatrogeneous vessel injuries without global anesthesia is not increased but outcomes in case of conscious sedations are better compared with intubation and general anesthesia.

[Normal pressure hydrocephalus]. / Normaldruckhydrozephalus.

CLINICAL ISSUE: Normal pressure hydrocephalus (NPH) is a disorder found mainly in the elderly (> 60 years) with an increasing prevalence with age and is one of the few treatable causes of dementia. If untreated NPH often leads to severe motor, psychomotor and irreversible cognitive deficits. The pathogenesis is not yet fully understood. Clinical symptoms consist of the (not always complete) classical triad of equilibrium and gait disturbances followed later by incontinence and dementia. Symptoms often show a gradual progression to irreversibility in non-treated patients; therefore, early diagnosis and treatment are mandatory. Important differential diagnoses are Parkinson's disease (similar gait), Alzheimer's disease and vascular dementia, not least due to the high comorbidity of these conditions with NPH. STANDARD RADIOLOGICAL METHODS: The standard radiological method for evaluation of NPH is conventional cross-sectional imaging that typically shows ventriculomegaly (Evans' index > 0.3 and cella media index < 4) often combined with the so-called disproportionately enlarged subarachnoid space hydrocephalus (DESH) pattern (tight convexity sulci and enlarged sylvian fissure). These findings should be differentiated from ventriculomegaly in atrophy combined with enlarged convexity sulci. METHODICAL INNOVATIONS: Special magnetic resonance imaging (MRI) techniques can be used to evaluate cerebrospinal fluid (CSF) flow but are not yet part of the diagnostic guidelines. ACHIEVEMENTS/PRACTICAL RECOMMENDATIONS: Combined with cross-sectional imaging, well-established clinical and invasive diagnostic tests, such as repeated spinal tap or lumbar drainage with re-evaluation of clinical symptoms lead to a diagnosis and help with preoperative patient selection for CSF diversion. Ventriculoperitoneal CSF shunting has proven to be safe and is the only known successful therapy for NPH.

[Postoperative spine]. / Postoperative Wirbelsäule.

Approximately 15-30 % of surgical procedures involving the lumbar spine are associated with complications that require further diagnostic work-up. The choice of imaging modality for postoperative complications depends on the extent, pattern and temporal evolution of the postoperative neurological signs and symptoms as well as on the preoperative clinical status, the surgical procedure itself and the underlying pathology. The interpretation of imaging findings, in particular the distinction between postoperative complications and normally expected nonspecific postoperative imaging alterations can be challenging and requires the integration of clinical neurological information and the results of laboratory tests. The combination of different imaging techniques might help in cases of equivocal imaging results.

[Spinal cord infarction]. / Spinaler Infarkt.

Infarction of the spinal cord can cause a variety of symptoms and neurological deficits because of the complex vascular supply of the myelon. The most common leading symptom is distal paresis ranging from paraparesis to tetraplegia caused by arterial ischemia or infarction of the myelon. Venous infarction, however, cannot always be distinguished from arterial infarction based on the symptoms alone.Modern imaging techniques, such as computed tomography angiography (CTA) and magnetic resonance angiography (MRA) assist in preoperative planning of aortic operations to reliably identify not only the most important vascular structure supplying the spinal cord, the artery of Adamkiewicz, but also other pathologies such as tumors or infectious disorders. In contrast to CT, MRI can reliably depict infarction of the spinal cord.

Predicting outcome of IV thrombolysis-treated ischemic stroke patients: the DRAGON score.

OBJECTIVE: To develop a functional outcome prediction score, based on immediate pretreatment parameters, in ischemic stroke patients receiving IV alteplase. METHODS: The derivation cohort consists of 1,319 ischemic stroke patients treated with IV alteplase at the Helsinki University Central Hospital, Helsinki, Finland. We evaluated the predictive value of parameters associated with the 3-month outcome and developed the score according to the magnitude of logistic regression coefficients. We assessed accuracy of the model with bootstrapping. External validation was performed in a cohort of 330 patients treated at the University Hospital Basel, Basel, Switzerland. We assessed the score performance with area under the receiver operating characteristic curve (AUC-ROC). RESULTS: The DRAGON score (0-10 points) consists of (hyper)Dense cerebral artery sign/early infarct signs on admission CT scan (both = 2, either = 1, none = 0), prestroke modified Rankin Scale (mRS) score >1 (yes = 1), Age (≥ 80 years = 2, 65-79 years = 1, <65 years = 0), Glucose level at baseline (>8 mmol/L [>144 mg/dL] = 1), Onset-to-treatment time (>90 minutes = 1), and baseline National Institutes of Health Stroke Scale score (>15 = 3, 10-15 = 2, 5-9 = 1, 0-4 = 0). AUC-ROC was 0.84 (0.80-0.87) in the derivation cohort and 0.80 (0.74-0.86) in the validation cohort. Proportions of patients with good outcome (mRS score 0-2) were 96%, 88%, 74%, and 0% for 0-1, 2, 3, and 8-10 points, respectively. Proportions of patients with miserable outcome (mRS score 5-6) were 0%, 2%, 5%, 70%, and 100% for 0-1, 2, 3, 8, and 9-10 points, respectively. External validation showed similar results. CONCLUSIONS: The DRAGON score is valid at our site and was reliable externally. It can support clinical decision-making, especially when invasive add-on strategies are considered. The score was not studied in patients with basilar artery occlusion. Further external validation is warranted.

[Inflammatory diseases of the spinal column and the myelon]. / Entzündliche Erkrankungen der Wirbelsäule und des Myelons.

Inflammatory diseases of the spine and the spinal cord (myelon) can be caused by a wide range of pathological conditions. Except for degenerative inflammatory diseases of the spine, infectious and autoimmune disorders are relatively rare. The latter can also be a significant source of pain and disability, especially if these hard to diagnose conditions go untreated. In cases of advanced disease some entities, such as spondylodiscitis or rheumatoid arthritis can cause severe neurological impairment especially by progressive intraspinal spread. Inflammation of the myelon cannot be depicted with conventional radiographs in general and by computed tomography only occasionally. In these cases magnetic resonance imaging is the method of choice to detect early abnormalities of the myelon and to provide detailed information for the differential diagnosis.

[Postoperative findings in the spinal column]. / Postoperative Befunde an der Wirbelsäule.

Postoperative imaging after spinal surgery is usually performed to document the correct positioning of implants or to rule out complications if patients still suffer from pain after surgery. Depending on the question various imaging modalities can be used all of which have benefits and limitations. Conventional X-ray is used for the documentation of the correct positioning of spinal implants, stability (olisthesis) and during follow-up to rule out fractures or instability of the implants, whereas soft tissue changes cannot be completely assessed. Besides these indications, imaging is usually performed because of ongoing symptoms (pain for the most part) of the patients. Soft tissue changes including persistent or recurrent herniated disc tissue, hematoma or infection can best be depicted using magnetic resonance imaging (MRI) which should be performed within the immediate postoperative period to be able to distinguish physiological development of scar tissue from inflammatory changes in the area of the surgical approach. Often imaging alone cannot differentiate between these and imaging can therefore only be considered as an adjunct. Computed tomography is the modality of choice for the evaluation of bony structures and an adjunct of new therapies such as image-guided application of cement for kyphoplasty or vertebroplasty.

[Spinal tumors]. / Spinale Tumoren.

Spinal tumors can be intramedullary, intradural (within the meninges), or extradural (between the meninges and the bones), or they may extend secondary to the spine from other locations. Vertebral hemangioma represents the most common benign tumor of the spine. Metastases, lymphoma, and multiple myeloma are the most frequent malignant spinal tumors. Primary osseous tumors of the spine, in contrast, are rare conditions but may demonstrate typical imaging findings. For the differential diagnosis, the patient's age, the topographic localization of the mass, and morphologic features of the lesion as depicted by computed tomography and magnetic resonance imaging play important roles.

[Magnetic resonance imaging and computed tomography findings in lacunar brain infarctions]. / Magnetresonanz- und computertomographische Befunde bei lakunären Hirninfarkten.

Lacunar brain infarctions belong to the most common causes of stroke and are typically located in basal ganglia with embolic, atheromatous or thrombotic etiology. Lipohyalinosis, often as a result of a long history of hypertension, can also be a cause of lacunar lesions. At present more than 20 different lacunar syndromes have been described. However clinical findings may be variable ranging from clinically"silent" to focal neurologic deficits to cognitive impairment. Magnetic resonance imaging (using diffusion-weighted sequences) generally allows diagnosis in most cases of acute lacunar infarcts and is superior to computed tomography especially in cases of additional leucoaraiosis.

[Stroke]. / Hirninfarkt.

Today stroke represents a major medical and political problem in Western industrial nations. High demands need to be placed on the initial diagnostic work-up and therapeutic treatment to ensure that the patients benefit from the recent advancements achieved in diagnostic and therapeutic fields. According to the motto "time is brain" the clinical examination and imaging have to be performed within 60 min ("door to needle time") so that potential patients can be quickly treated with systemic or intra-arterial lysis. However, it should be taken into consideration that the selection of diagnostic imaging facilities depends on several factors such as infrastructure, the time remaining in the diagnostic window, and the severity of the clinical symptoms.