The "dense artery sign"--major cerebral artery thromboembolism demonstrated by computed tomography.

A 4 years review of high resolution thin slice (3-5 mm) computed tomography performed within 24 h after cerebral infarction revealed increased density in a major cerebral artery segment in 28 patients. Arteries affected were the vertebral and basilar artery in 6 and 8 patients, the sphenoid course of the middle cerebral artery in 13 cases and the extracranial internal carotid artery in 1 patient. In 35.7% of cases the so called "dense artery sign" provided earliest evidence of the ensuing infarction documented by CT controls in most patients. Angiography carried out in 8 patients, density calculations in the course of the affected vessel and resolution of the increased density on subsequent CT examinations suggest thrombembolism as the most likely etiology. In the clinical setting of acute stroke increased artery density encompassing the entire vessel diameter may serve as an early indicator of major cerebral artery occlusion and prompt angiographic investigation of a lesion potentially amenable to lysis.

Occurrence of MRI abnormalities in patients with isolated optic neuritis.

24 patients with clinically isolated optic neuritis (ON) were examined with MRI. Only 5 patients (22.9%) had a normal MRI scan. The number of detected clinically silent lesions ranged from 0 to 38. They were mainly located in the frontal and parietal white matter. All patients with more than 3 lesions on MRI had pathological findings in CSF. There was no correlation between the number and location of lesions and age at onset of ON.

Magnetic resonance imaging in the evaluation of treatment in multiple sclerosis.

Magnetic resonance scans of 74 patients with multiple sclerosis participating in a controlled trial were compared 6 months before and at the end of a 24-32 months-treatment period with either Cyclosporin A (n = 31) or Azathioprine (n = 43). Both qualitative rating and computation of lesion volume showed deterioration in more than 40% of the patients, while by clinical criteria only 10-30% were worse. No significant difference was noted when the two treatment groups were compared. If careful repositioning and standardized image parameters are used, MRI is an indispensable tool for the objective determination of disease progression in MS although it cannot replace clinical examination.

[Computerized tomography findings following successful lumbar intervertebral disk surgery]. / Computertomographische Befunde nach erfolgreicher lumbaler Bandscheibenoperation.

Computed tomography findings were studied after successful lumbar disk surgery. All patients were asymptomatic after the operation thus presenting morphological changes that probably correspond to regular postoperative conditions. Small seromas in the area of surgery are well-known "normal" findings and have no pathological significance. Dorsal bulging at the level of the intervertebral disc operated upon has not yet been studied systematically. This protrusion that can even exceed the preoperative amount of bulging is due to swelling and folding of the posterior longitudinal ligament. In our patients it disappeared spontaneously within a few months and it should not be confused with real recurrent or residual disc herniation.

[Pulse synchronous vascular tinnitus: radiologic diagnosis and therapy]. / Pulssynchroner vaskulärer Tinnitus: Radiologische Diagnostik und Therapie.

Tinnitus synchronous with the pulse is usually caused by vascular anomalies. In our own patient group we found the most frequent cause to be highly vascularised tumours related to the pretrous bone, the most common being glomus tumours. Pulsatile tinnitus however also is a main symptom of dural arterio-venous malformations with shunts into the transverse and sigmoid sinus. Finally pulsatile tinnitus may be caused by venous deformities, possibly combined with anomalies of the bulb of the jugular vein. While clinical methods give valuable clues to the type of pathological findings, subtle radiological investigations are necessary for the final diagnosis, such as high resolution computer tomography and super-selective angiography. There has been substantial progress in recent years due to technical developments leading to improved diagnosis and treatment by interventional radiology.

[Tinnitus and its radiological diagnosis and therapy]. / Ohrgeräusche und ihre radiologische Diagnostik und Therapie.

Tinnitus is a familiar symptom in diseases of the central nervous system. Its aetiology being of a varied nature, the type of tinnitus is a pointer to the pathoanatomic findings that are responsible for the disease. The causes of tinnitus are often found in the borderline areas between various neighbouring disciplines, such as otology, neurology and neurosurgery, whereas the final identification of the real causes is mainly within the scope of radiological diagnosis, in which computed tomography and superselective angiography play an essential role. In addition to arteriovenous fistulas near the petrous bone and glomus tumours, which are well known, there are a few other aetiologies of pulse-synchronous tinnitus that are being discussed in this paper. In recent years there has been substantial therapeutical progress owing to the introduction of new techniques and the development of improved materials for embolisation in interventional neuroradiology. Their application is discussed in connection with various patient groups.

An attempt to quantify magnetic resonance imaging in multiple sclerosis--correlation with clinical parameters.

The diagnostic value of magnetic resonance imaging (MRI) in multiple sclerosis (MS) is uncontested. But only little information exists on its usefullness in monitoring disease activity. We describe a method of quantification that can be performed in longitudinal MRI-investigations. We used a standardized method of scanning and determined the area of demyelinating lesions with an interactive planimetric computer system. In order to determine the approximate lesion volumes, the computed area was multiplied by the slice thickness. In 89 patients with clinically definite MS we found an average lesion volume of 11900 mm3. The mean score in Kurtzke's expanded disability scale was 3.0. The correlation between computed lesion volume and neurological deficit was significant, but only weak (rho = 0.3). We conclude, that planimetric evaluation of MRI can be a valuable supplement to clinical rating scales in MS patients. The method described here, used in combination with high spacial resolution and better tissue specificity of latest generation MRI scanners, could be helpful in the evaluation of treatment in many other CNS diseases.

[Central traumatic cerebral hemorrhage in the computed tomogram]. / Zentrale traumatische Hirnblutungen im Computertomogramm.

Traumatically caused central brain haemorrhages are relatively rare. From 1976 through 1984 3598 patients were submitted to computed tomography examination in our department after craniocerebral trauma. Central lesions could only be found in about 3% of the injured. They generally occurred in combination with other severe damage of the skull and skull contents. Most frequently, such central haemorrhages could be found in the basal ganglia occasionally extending into the adjacent medullary layer resulting in large intracerebral haematoma. The right hemisphere was affected significantly more frequently and more severely by such large-size haemorrhages than the left hemisphere. The thalamus region ranking second in localisation of central traumatic haemorrhages was virtually never found to be the origin of large haematomas. In general, no definite distinction could be made between primary and secondary traumatic haemorrhages. We identified, however, a few cases of purely central bleeding without accompanying brain lesions. These haematomas, which were most probably caused primarily by trauma, as well as those with associated damage, preferred the regions of basal ganglia and thalamus. The prognosis of central brain haemorrhages was relatively poor with a 42% lethality rate. However, it depended on the severity of the accompanying brain lesions. Thus, isolated central haemorrhages even had a markedly favourable prognosis. The number of survivors of central bleeding turned out to be approximately the same as the number of deaths, the ratio thus being 1:1. Nevertheless, we think that especially small lesions occur more frequently and have a better survival rate than had been supposed up to now.

Brain tumor CT attenuation coefficients: semiquantitative analysis of histograms.

This paper reports on work in progress on semiquantitative curve analyses of histograms of brain tumors. Separation of statistical groups of attenuation values obtained by computer calculation is done separately from scanning, using histogram printouts as the data input for a programmable calculator. This method is discussed together with its results in 50 cases of malignant gliomas. The detection of hidden tissue portions and the more accurate evaluation of partial enhancement effects have been the investigators' main concerns to the present time; however, this method may allow more specific diagnosis of malignancy and changes in tumor characteristics than visual assessment alone. This has not been proven by studies that have evaluated large numbers of cases, but seems to be worth pursuing as a new approach.

[Reliability of CT diagnosis in cerebral sinus thrombosis]. / Zur Sicherheit der CT-Diagnose bei zerebralen Sinusthrombosen.

There is no reliable CT diagnosis in all cases of cerebral sinovenous thrombosis. The hyperdense sinus structures may indicate an acute thrombotic occlusion, but we know other reasons of this finding. Only the so-called empty triangle sing is pathognomonic, while the unilateral or bilateral hemorrhages, circumscript or diffuse edema with small ventricles and the tentorial hypervascularity are not specific of sinovenous occlusion. We present our findings in 15 cases of sinovenous thrombosis and conclude, that the combination of clinical course and CT-finding with specific or some non-specific signs will give the correct diagnosis of sinus thrombosis with or without angiography.

[Midline-malformations of brain shown by computed tomography (author's transl)]. / Zerebrale Mittellinienfehlbildungen im axialen Computertomogramm.

The so-called midline-malformations of the brain which include alterations of ventricles or arachnoid spaces formerly only were found by invasive procedures performed because of their various clinical signs. Since cranial computerized tomography is available, by this new noninvasive method all these disturbances can be diagnosed safely. The paper is referring to the most frequent and essential exponents of these midline-malformations together with their main features in anatomy, pathomorphology, clinical and radiological signs. The persistent performed cavities especially the cavum septi pellucidi, the cavum Vergae and the cavum veli interpositi, additionally the agenesis of the corpus callosum, the Dandy-Walker-syndrome and the Chiari-malformations are described by typical cases. In conclusion the reliability of diagnosis in all cases of midline-malformations will be mostly sufficient by plain axial computed tomograms due to very clearly defined unmistakable pictures.

[Watershed infarctions--a special type of infarction in cases with carotid artery stenosis or occlusion verified by CT and angiography (author's transl)]. / Der Grenzzoneninfarkt als besondere Infarktkonstellation bei Karotisinsuffizienz. Eine computertomographisch-angiographische Korrelationsstudie.

Watershed infarctions appear in the axial CT-sections mostly as stained or striated hypodense areas in the white matter of the parietal and seldom temporal region, without or with extension into the supply area of the adjacent cerebral arteries. We observed these changes in approximately 40% of our series with carotid artery stenosis or occlusion. These findings may be very subtle, and in such cases angiography should be performed.

[Neurogenic sarcoma of the head and neck with contact to the skull base (author's transl)]. / Das neurogene Sarkom im Kopof-Halsbereich mit Kontakt zur Schädelbasis.

The neurogenic sarcoma is a neoplasm found seldom. It descends from the sheaths of peripheric nerves. If this tumor develops from a solitary or multiple neurofibroma, it might also be called a neurofibrosarcoma. All other synonyms, especially that of the malignant schwannoma, should better be abandoned for histogenetic reasons. Today the classification of all tumors of the peripheral nervous system is based on a suggestion of the WHO from 1969. The tabular summary of the literature shows that only a little more than a hundred cases of neurogenic sarcoma of the head and neck were reported during the last 50 years. Differential diagnosis of this malignant tumor includes nearly all other malignant neoplasms of soft tissue, sometimes even anaplastic carcinoma. Histopathology, including electron microscopy, is described in general and also in detail with regard to three cases. Three forms of micro-morphological variants are dealt with, too. For diagnosis histological examination will be absolutely successful only in cases of neurofibromatosis or in cases where the nerve from which the tumor originates may be identified. Otherwise, conventional and computerized X-ray tomography may be helpful. Finally, some therapeutic and prognostic principles are discussed.

CT-findings in a case of clover-leaf skull.

The authors report a detailed CT-investigation of "clover-leaf skull" and compare the findings with cases reported by others.

[Topographic correlation of angiographic and CT findings in cerebrovascular disease (author's transl)]. / Topographische Korrelation angiographischer und computertomographischer Befunde bei zerebralen Gefassprozessen.

Problems of correlating ischemic lesions of the brain with the cerebral vessel involved originate in the axial scanning direction. It is almost impossible to line out precisely the borders of the cerebral lobes--far less are we able to describe exactly the areas supplied by the cortical branches of the anterior or middle cerebral artery. Using a method based on detailed perception of the base of the skull and physiological calculations, it is possible to reconstruct the individual baseline of the scan and to project the outlines of the slices upon the lateral view of the angiogram. Thereby a reliable topographical association between CT findings and angiogram is given.

Giant aneurysms in CT and angiography.

Giant intracranial aneurysms are frequently observed as incidental findings on CT and angiograms obtained for purposes other than subarachnoid hemorrhage, such as slowly evolving nerve palsy or hemiparesis. Since giant aneurysms often thrombose, the CT scan may demonstrate a larger aneurysmal volume than the angiogram. This paper presents CT and angiogram findings in cerebral aneurysms with a diameter of 25 mm-60 mm. The discussion covers: sort of aneurysm (congenital, arteriosclerotic); type and degree of thrombosis; long-term results after spontaneous thrombosis; and CT examination after using epsilon-aminocaproic acid.

[Angio-tomographic aspects of cerebral aneurysms and angiomas (author's transl)]. / Angiotomographische Aspekte der zerebralen Aneurysmen und Angiome

Angio-tomography is a selective radiological method which can be used to complement serial angiographs in order to demonstrate better detail. This results from the fact that selective levels can be demonstrated without super-imposition of bone or other vessels. Angio-tomography combines the advantages of tomography, subtraction and selective procedures. The method has been used for all types of intracranial disease; aneurysms and angiomas are the most common conditions for which angio-tomography has been employed. The present paper is based on a total of 60 cerebral aneurysms and angiomas in various situations; angiotomography was indicated for these amongst a larger material of intracranial vascular malformations in which the diagnosis was possible without its use. The indications consist of: 1) Demonstration of very small aneurysms and their differentiation from vessel loops, 2) Demonstration of the origin of an aneurysm which is situated at the confluence of several major vessels, 3) Point of origin of a so-called hugeaneurysms which cannot otherwise be shown by oblique views, 4) Demonstration of so-called micro-angiomas and of the afferent and efferent vessels in central arterio-venous malformations. Unusual aneurysms of the internal carotid artery, of the anterior choroidal and vertebral arteries are described. Some new concepts in the localisation of aneurysms of the anterior communicating artery are discussed. Many of the examinations were carried out with an angio-tomographic apparatus made in the department.

Serial angiotomography in supratentorial tumors.

Serial angiotomography is a selective investigative method which contributes to exact differential diagnosis and localization of the tumor. With the localization near the midline of the supratentorial tumors it can occasionally be the only arteriographical method which will bring a definite result. With basal processes the relationship of the tumor to the bones and dura can be demonstrated more accurately. In addition angiotomography brings new haemodynamic aspects with regard to the circulation time and intensity of the tumor stain of glioblastoma.