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Sixty-one acoustic neuromas were examined with computed tomography (CT). For differential diagnosis the tumors were thoroughly analyzed for manner of growth, shape, volume, calcification, attenuation pattern, constrast enhancement, presence of peripheral edema, and cisternal deformation.

Computed tomography (CT) has been reported to show normal findings in 13-52% of patients with cerebrovascular diseases. Among factors deciding the diagnostic accuracy are the size and location of the lesion, the time elapsed from onset to examination, the use of contrast enhancement and the type of CT scanner used. To further elucidate these aspects, we designed the present study including 300 consecutive patients, all investigated by CT with a 160 x 160 matrix and cerebrospinal fluid spectrophotometry (CSF-SPE). CT indicated a specific diagnosis in 52.7%. In the majority of the remaining cases, additional subclassification was possible by CSF-SPE, emphasizing the complementary information obtained by combined examinations. CT was also found to be a useful tool for reliable prognostic prediction, irrespective of the initial clinical course.

Summary. Using a continuous-wave ultrasound Doppler system with spectral analysis (FFT) and digital processing and presentation, the Doppler shift characteristics of the carotid arteries were studied in 40 healthy subjects (20 men and 20 women; average age 69 years). The reference values, thus obtained, were applied to the analysis of sonograms from 46 carotid arteries, which were also studied angiographically. Stenoses which reduced the diameter of the internal carotid artery by more than 30% could be identified with a sensitivity of 97% and a specificity of 100%. The results extend previous experience that spectral analysis improves the usefulness of the ultrasound Doppler system in the evaluation of carotid artery disease. The addition of digital processing and presentation of the Doppler shift characteristics increases the diagnostic precision and provides a permanent record. The importance of well-trained sonographers and adequate reference values is emphasized.

Equimolar doses of iohexol and metrizamide (0.48 mmol/kg body weight = 185 mg I/kg), administered in solutions iso- and hyperosmolar to the CSF, were injected subarachnoidally into rabbits under pentobarbital anaesthesia. No excitative effects of iohexol were observed in the behaviour of the rabbits during a 3-h period immediately after the injection. Metrizamide caused significant, severe excitative effects, ranging from hyperexcitability to repeated generalized seizures. The frequency and severity of excitative effects were independent of the osmolality of the metrizamide solutions injected.

The immunohistochemical expression of insulin-like growth factor I (IGF-I; somatomedin C) was investigated in hindlimb skeletal muscle of rats during postnatal development. IGF-I immunoreactivity could be demonstrated in satellite fibres and myotubes 1, 2 and 3 days after birth, while no IGF-I immunoreactivity could be demonstrated in the more mature primary fibres. Five days after birth only scattered cells showed IGF-I immunoreactivity and 10 days after birth no specific IGF-I immunoreactivity could be demonstrated in muscle cells, i.e. the adult pattern was established. It is concluded that IGF-I immunoreactivity is expressed during a limited period of postnatal skeletal muscle maturation in rats. IGF-I is probably synthesized by IGF-I immunoreactive muscle cells and contributes to the differentiation/maturation process by autocrine and/or paracrine mechanisms.

Seven pontine angle meningiomas were examined with computed tomography (CT). The result was compared with that of a study of 61 acoustic neuromas. These two tumor types differ in manner of growth, volume, shape, attenuation, attachment to bone, cisternal deformation, frequency of calcification, peripheral edema, and bone changes.

Forty-seven patients with 48 unoperated acoustic neuromas have been studied by computed tomography (CT) with respect to bone changes. CT and conventional X-ray examination of the skull were compared. The importance of using a small collimator, proper selection of the plane of the CT section and changing of the window level is stressed. CT detects porus changes as accurately as conventional X-ray methods.

The changes of the enhancement of the lesion with time after intravenous administration of contrast medium were measured with computed tomography (CT) in 23 cases of acoustic neuroma. The pattern of high initial enhancement followed by a fairly rapid decrease is confirmed. A more rigorous study of the enhancement pattern using a mathematical description of the enhancement curve of the tumor as well as a measurement of the individual blood enhancement curve is discussed.

Attenuation profiles across the petrous bone covering the whole internal auditory meatus (IAM) were constructed from the printouts obtained by computed tomography (CT) with narrow collimation performed on 12 patients with 13 acoustic neuromas. In healthy patients the attenuation profiles of right and left petrous bone were very similar in shape. The attenuation values of the individual pixels in the pixel columns of the printout located at the site of the porus and the IAM reflected the demineralization of the petrous bone and the widening of the porus and the IAM caused by the acoustic neuroma. A widening deep in the meatus was demonstrated in a patient with an intracanalicular tumor, and therefore it seems possible to make this diagnosis by CT scanning combined with the construction of attenuation profiles across the petrous bone. In the presence of unilateral acoustic neuroma there was a significant and characteristic difference in shape between the attenuation profiles of the two sides with generally lower attenuation values on the tumor side together with signs of widening of the porus and the IAM. In cases of bilateral acoustic neuroma comparison of the attenuation profiles can be made with mean attenuation curves obtained from scanning normal petrous bones. The prevailing physical limitations for demonstrating a narrow bony canal like the IAM with CT was experimentally analyzed using bone-simulating plastic material.

The incidence of thrombosis during one year in a defined population of 263 144 city inhabitants has been studied with a new method based upon acute phlebography of all patients with the slightest symptoms of the disease. The roentgenographic pattern of the acute thrombosis has been studied and the size of the individual thrombus has been compared with the duration of the symptoms. The incidence of thrombosis was found to be 0.9 per mille per year. No correlation was found between the size of the thrombus and the duration of the symptoms. The thrombus had its origin in the calf veins in 89% of the patients and its origin in a vein at a higher level in 10% of the patients. In patients with a thrombus confined to the calf veins the contrast medium always entered the deep crural veins. When the calf vein thrombosis had an extension to the popliteal vein or still higher up the contrast medium bypassed the deep crural veins in more than 75% of the patients.

The prevalence of ulceration in the carotid bifurcation, as judged from high-resolution 2-D ultrasound scanning and angiography, was compared with the findings at carotid endarterectomy in patients with TIA or stroke. The surgeons registered ulceration in 26 of the 29 treated carotid arteries. Angiography and ultrasonography identified ulceration in 9 and 19, respectively, of the same arteries, indicating that high-resolution 2-D ultrasound scanning is superior to angiography in the diagnosis of carotid ulceration. All arteries with tight stenosis (diameter reduction greater than or equal to 75%), but only two of four with less than 30% stenosis were ulcerated.

Most aneurysms coming to the attention of a clinic have reached, or exceeded, the maximum size compatable with the tenuous walls of the malformation. Since the difficulties encountered at operation are often in direct proportion to the dimensions of the lesion, a small malformation, often presenting with intracranial hemorrhage, offers a relatively better surgical prognosis.

Die jetzt wohl als klassisch zu betrachtende Arbeit Schullers: „Die Schadelbasis im Rontgenbilde“, 1905, ist die Grundlage aller spateren Arbeiten auf diesem Gebiete. In der folgenden Zeit, in der so viele Fragen der Rontgendiagnostik auf der Tagesordnung standen, wurde der Schadelrontgenologie, soweit sie die Diagnostik der Hirntumoren betrifft, geringes Interesse gewidmet, da die chirurgische Behandlung von Hirntumoren als sehr undankbar betrachtet wurde. Einzelne Publikationen uber Falle von diagnostizierten Hirntumoren erschienen hie und da. Im allgemeinen wurden diese aber als reine Gelegenheitsbefunde betrachtet und es herrschte ein groser Pessimismus, der auch in den Kongresdiskussionen zum Ausdruck kam. Durch die Arbeiten Cushings und anderer Chirurgen uber die Behandlung von Hirntumoren ist die Frage viel aktueller geworden. In den letzten 10 Jahren ist eine grose Literatur auf diesem Gebiete zustande gekommen und gleichzeitig mit der stetigen Vervollkommenung der rontgenologischen Technik nahm die Anzahl positiver Falle zu und man versuchte die Rontgendiagnostik bei Tumor cerebri mehr zu systematisieren.