[Spondylodiscitis and epidural abscesses]. / Spondylodiszitis und epiduraler Abszess.

CLINICAL/METHODOLOGICAL PROBLEM: Spondylodiscitis is an inflammation of the intervertebral disc, which in adults is generally associated with spondylitis of the adjacent vertebrae. It often presents clinically with nonspecific symptoms such as back or neck pain. It may be caused by various pathogens, especially bacteria. One or more vertebral segments can be affected. The infection can spread to surrounding compartments and can lead to epidural abscesses. Radiology, in particular magnetic resonance imaging (MRI), plays an important role in the diagnostic work-up and in the follow-up to monitor response to therapy. Treatment consists of conservative (antibiotics) and invasive approaches, including surgery. Interventional puncture and drainage is a promising alternative to surgery, especially in early stages of abscess formation. STANDARD RADIOLOGICAL METHODS: Magnetic resonance imaging (MRI), computed tomography (CT), nuclear medical procedures, conventional x­ray. PERFORMANCE: MRI has the highest value. CT and nuclear medical procedures can be used as a supplement to MRI and in patients with contraindications for MRI. PRACTICAL RECOMMENDATIONS: With adequate diagnosis and therapy, spondylodiscitis has a good prognosis. In addition to targeted or calculated drug therapy, invasive treatment is the main focus, especially for epidural abscesses. Interventional radiological drainage can represent a less invasive alternative to surgical treatment.

[Spinal ozone therapy]. / Spinale Ozontherapie.

CLINICAL/METHODOLOGICAL PROBLEM: Technical advances in the field of spinal interventional neuroradiology allow the application of a wide range of targeted, minimally invasive treatment options including targeted spinal ozone therapy for back pain. This article provides an overview of the biochemical, molecular, immunologic, and pharmaceutical mechanisms and delivery techniques of targeted ozone therapy. STANDARD RADIOLOGICAL METHODS: Computed tomography (CT), conventional X­ray (fluoroscopy). PERFORMANCE: Computed tomography-guided interventions (epidural, periradicular, facet joint, and intradiscal) have the highest place value and have historically prevailed. Fluoroscopy-guided procedures may also be used. PRACTICAL RECOMMENDATIONS: Ozone therapy provides promising results. The article is intended to provide information on the basics of the technique(s).

[Malignant tumors of the oral cavity]. / Tumoren der Mundhöhle.

CLINICAL/METHODICAL ISSUE: Oral cavity malignancies are the most common tumors in the field of ear, nose and throat medicine or otorhinolaryngology worldwide. It comprises a heterogeneous group of tumors, the knowledge of which is necessary to meet the different requirements of diagnostics and therapy. STANDARD RADIOLOGICAL METHODS: Computed tomography (CT), magnetic resonance imaging (MRI), sonography (US), nuclear medical procedures (NUK). PERFORMANCE: The above-mentioned diagnostics are used in a complementary manner. ACHIEVEMENTS: Early diagnosis of the tumor improves staging and thus the patient's therapy and prognosis. PRACTICAL RECOMMENDATIONS: The radiologist plays an important role in the interdisciplinary treatment of malignant tumors of the oral cavity. Despite great progress in radiotherapy, oncology and immunotherapy, surgery still plays an important role in the treatment of malignant diseases of the oral cavity.

[Degenerative intervertebral disc processes : Current aspects of diagnosis]. / Degenerative Bandscheibenprozesse : Aktuelles zur Befundung.

Starting with the smallest functional unit, the spinal segment including the centrally located intervertebral disc, the spine and pelvis including the sacroiliac and hip joints form a functional unit. The discs play an important role in the complex interaction between disc, osseous and ligamentous structures and the adjacent muscles. Disc pathologies are very frequently associated with changes of the adjacent endplates of the vertebral bodies and can be depicted at an early stage using magnetic resonance imaging (MRI). The focus of the diagnostics and assessment of degenerative disc pathologies should be centered on the clinical problem. The basis for this is the use of a uniform terminology between the disciplines involved.

[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.

[Intracranial cystic lesions]. / Intrakranielle zystische Läsionen.

CLINICAL PROBLEM: Intracerebral cysts are common findings in imaging of the neurocranium and are not always clinically significant. The pathological spectrum of intracerebral cysts is, however, very broad and in addition to incidental findings includes developmental disorders, malformation tumors, primary and secondary neoplasms and infectious etiologies, such as cerebral abscess formation, cysticercosis or residuals after congenital cytomegalovirus infections. Intracerebral cystic defects may be caused by inflammatory central nervous system (CNS) diseases, such as multiple sclerosis as well as by mitochondriopathies, leukodystrophy, electrolyte disturbances or osmotic demyelination syndrome or brain infarctions, e.g. after lacunar infarctions or as encephalomalacic changes after severe traumatic brain injury. RADIOLOGICAL STANDARD PROCEDURES: In addition to the radiological findings of cysts in magnetic resonance imaging (MRI) or in computed tomography (CT), the localization, patient age, patient medical history and laboratory diagnostics are helpful for the differential diagnostics. METHODICAL INNOVATION: In addition to the morphological assessment, advanced MRI techniques, such as diffusion-weighted imaging for epidermoids or the use of MR spectroscopy, can provide valuable information for the differential diagnosis. PERFORMANCE/ASSESSMENT: Intracranial cysts can be subdivided into intraventricular and periventricular cysts, intra-axial cysts and cysts in the external fluid-filled spaces. Associated tumor nodules and the contrast medium behavior of the cyst walls and/or associated soft tissue components as well as the reaction of the adjacent parenchyma are helpful for the diagnosis and assessment.

[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.

[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.

[Kyphoplasty and vertebroplasty for spinal trauma]. / Kyphoplastie und Vertebroplastie bei Wirbelsäulentraumata.

CLINICAL ISSUE: Minimally invasive treatment of spinal fractures. STANDARD TREATMENT PROCEDURES: Conservative treatment versus spinal surgery. TREATMENT INNOVATIONS: Minimally invasive stabilization techniques, such as percutaneous (assisted) cementoplasty have been introduced as new procedures. DIAGNOSTIC WORK-UP: Magnetic resonance imaging (MRI), X­rays and computed tomography (CT) are the imaging techniques of first choice. The most important questions concern recent fractures, instability and indications for minimally invasive treatment. PERFORMANCE: Vertebroplasty and kyphoplasty are established methods for the treatment of patients with osteoporosis. ACHIEVEMENTS: Cementoplasty techniques are promising treatment options for traumatic spinal injuries. PRACTICAL RECOMMENDATIONS: The application of the techniques should best be carried out in individual cases within the framework of prospective controlled studies.

New ischaemic brain lesions in cervical artery dissection stratified to antiplatelets or anticoagulants.

BACKGROUND AND PURPOSE: To determine the frequency of new ischaemic or hemorrhagic brain lesions on early follow-up magnetic resonance imaging (MRI) in patients with cervical artery dissection (CAD) and to investigate the relationship with antithrombotic treatment. METHODS: This prospective observational study included consecutive CAD patients with ischaemic or non-ischaemic symptoms within the preceding 4 weeks. All patients had baseline brain MRI scans at the time of CAD diagnosis and follow-up MRI scans within 30 days thereafter. Ischaemic lesions were detected by diffusion-weighted imaging (DWI), intracerebral bleeds (ICBs) by paramagnetic-susceptible sequences. Outcome measures were any new DWI lesions or ICBs on follow-up MRI scans. Kaplan-Meier statistics and calculated odds ratios with 95% confidence intervals were used for lesion occurrence, baseline characteristics and type of antithrombotic treatment (antiplatelet versus anticoagulant). RESULTS: Sixty-eight of 74 (92%) CAD patients were eligible for analysis. Median (interquartile range) time interval between baseline and follow-up MRI scans was 5 (3-10) days. New DWI lesions occurred in 17 (25%) patients with a cumulative 30-day incidence of 41.3% (standard error 8.6%). Occurrence of new DWI lesions was associated with stroke or transient ischaemic attack at presentation [7.86 (2.01-30.93)], occlusion of the dissected vessel [4.09 (1.24-13.55)] and presence of DWI lesions on baseline MRI [6.67 (1.70-26.13)]. The type of antithrombotic treatment had no impact either on occurrence of new DWI lesions [1.00 (0.32-3.15)] or on functional 6-month outcome [1.27 (0.41-3.94)]. No new ICBs were observed. CONCLUSION: New ischaemic brain lesions occurred in a quarter of CAD patients, independently of the type of antithrombotic treatment. MRI findings could potentially serve as surrogate outcomes in pilot treatment trials.

[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.

[Typical tumors of the petrous bone]. / Typische Tumoren des Felsenbeins.

In the region of the petrous bone, inner acoustic canal and cerebellopontine angle, a variety of different tissues can be found, such as bony, epithelial, neural and vascular structures. Tumorous or tumor-like lesions, vascular or bony malformations or other pathologies can therefore be found in all of these areas. We discuss various frequently occurring tumorous or tumor-like pathologies including congential lesions, such as mucoceles, inflammatory disorders including osteomyelitis, pseudotumors and Wegener's granulomatosis. Benign non-neoplastic lesions, such as cholesteatoma, cholesterol granuloma, epidermoid and benign neoplastic tumors, such as the most commonly found vestibular schwannoma, meningeoma, paraganglioma, vascular pathologies and finally malignant lesions, such as metastasis, chordoma or chondrosarcoma and endolymphatic sac tumor (ELST) are also discussed. The emphasis of this article is on the appearance of these entities in computed tomography (CT) and more so magnetic resonance imaging (MRI), it provides key facts and typical images and discusses possibilities how to distinguish these pathologies.

[Pediatric intraspinal neoplasms]. / Pädiatrische intraspinale Neoplasien.

With an overall incidence of 10% of all central nervous system tumors, spinal tumors are relatively rare in children. The majority of these tumors are astrocytomas and ependymomas (70%) followed by rare non-glial tumor entities, such as gangliogliomas. They can be differentiated into intramedullary, extramedullary intradural and extramedullary extradural tumors according to their occurrence within the anatomical intraspinal compartments. The clinical presentation is generally unspecific. Longer lasting back pain or a gradually worsening scoliosis are often the first signs of the disease. Neurological deficits, such as gait disturbances and paresis often occur after a time delay. In rare cases increased intracranial pressure has been reported.Knowledge concerning potential organ manifestations, resulting complications and typical radiological presentation, especially in magnetic resonance imaging are mandatory for adequate diagnosis and treatment of affected patients.

[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.

[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.

[Osler's disease]. / Morbus Osler.

Osler's disease, also known as hereditary hemorrhagic telangiectasia (HHT) and Osler-Weber-Rendu syndrome, is an autosomal dominant disorder leading to abnormal blood vessel formation in the skin, mucous membranes and often in organs, such as the lungs, liver and brain (arteriovenous malformations AVM). Various types are known. Patients may present with epistaxis. Teleangiectasia can be identified by visual inspection during physical examination of the skin or oral cavity or by endoscopy. Diagnosis is made after clinical examination and genetic testing based on the Curacao criteria. Modern imaging modalities, such as computed tomography (CT) or magnetic resonance imaging (MRI) have become more important as they can depict the AVMs. Pulmonary AVMs can be depicted in CT imaging even without the use of a contrast agent while other locations including the central nervous system (CNS) usually require administration of contrast agents. Knowledge of possible clinical manifestations in various organs, possible complications and typical radiological presentation is mandatory to enable adequate therapy of these patients. Interventional procedures are becoming increasingly more important in the treatment of HHT patients.

[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.

[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.

[Neuroradiological focus on stroke imaging]. / Fokussierte neuroradiologische Diagnostik beim akuten Hirnschlag.

Stroke is heterogenous in its symptoms, which are also caused by various pathologies. Clinically the causing mechanism (bleeding or ischemia) of a new onset of neurological deficits can not reliably be distinguished. However, ischemia is four times more frequent than a bleeding causing neurological symptoms. Modern imaging technologies (computed assisted tomography or magnetic resonace imaging) and interventional techniques are a mainstay in diagnostics and management of acute onset of neurological symptoms. They can reliably distinguish between bleeding and stroke, especially taking newest technologies, such as perfusion studies and angiographies, into account. Neuroradiology with its interventional options has nowadays furthermore become an important tool in strokes and offers a local maneuver to retrieve the clotting pathology and even opens the therapeutic window for a delayed start of the therapy since symptom's onset beyong the conventional 4.5 hours window. Also risks of a therapy and which therapy option should be used can immediately be assessed.