Computed tomography of the head: clinical experience of the first 3000 scans with EMI scanner

Computer tomography (CT) findings obtained from the first 3,000 scans on 2,031 patients were analyzed and discussions were made on various kinds of neurological diseases, especially from the neurosurgical point of view. CT showed an excellent resolution for three-dimensional morphological pattern of intracranial lesion with a high percentage of diagnostic accuracy as reported from other institutes, resulting in making much earlier morphological diagnosis of intracranial lesion possible than any other examination. Scan methods consisted of plain CT, contrast enhanced CT, and metrizamide CT cisternography. Sequential delayed enhanced CT offered more useful information for high diagnostic accuracy, particularly for nature of brain tumor. Metrizamide CT cisternography was performed for the evaluation of cerebrospinal fluid dynamics and diagnosis of skull base tumors. CT is a new, epoch-making and non-invasive diagnostic approach in neuroradiology and contributes to obtain the better achievement of neurosurgical results.

[Radioisotope cisternographic study on intracranial arachnoid cyst (author's transl)]

The dynamics of the CSF circulation in six cases of intracranial arachnoid cysts was examined by RI cisternography suing 0.5 to 1.0 mCi of 169Yb DTPA or 50 to 100 microCi of 131I HSA injected into the lumbar subarachnoid space. Serial scintigrams were obtained with rectilineal scintillation scanner at 2, 4, 6, 24 and 48 hours after injection. The communication of the cavity of arachnoid cyst and subarachnoid space was recognized in all cases. The cysts were best visualized at 24 hours in most cases. Four patterns of the entry and stasis of RI in cysts were observed as follows, 1) rapid filling of RI into the cyst and delayed clearance, 2) both rapid filling and clearance, 3) slow filling and delayed clearance, 4) no filling.

Operative nephroscopy with fiberoptic scope: preliminary report

New fiberoptic scopes, originally designed for biliary tract operations, were used in 23 cases for removal of residual calculi at pyelolithotomy and for examination of the renal pelvis and ureter. The external diameters of the scopes are 6.6 mm. (CHF-X1) and 4.5 mm. (CHF-X2). Water irrigation and forceps manipulation can be performed simultaneously with the CHF-X1 scope but only irrigation can be done with the CHF-X2 scope. The scopes were reliable and allowed easy endoscopic forceps manipulation. Improvements for an ideal fibroptic nephroscope are discussed.

Diagnostic value of CT cisternography with intrathecal metrizamide enhancement, comparison with isotope cisternography

Metrizamide CT cisternography (CTC) was performed for the evaluation of CSF dynamics and the diagnosis of skull-base tumors. Results of CTC in 52 cases examined for the study of CSF dynamics correlated well with those of isotope cisternography. However, the degree and duration of ventricular stasis of metrizamide and its transition into a periventricular low-density area in hydrocephalus were recognized more accurately in CTC. Twenty out of 23 cases with suspected skull-base tumor were diagnosed as positive and confirmed by operation. CTC was especially useful in parasellar, CP angle, and other posterior fossa tumors.

Sequential delayed enhanced CT in brain tumors

Delayed enhanced CT was performed in 53 cases and these findings are compared with those of delayed radioisotope scan and with operative and histopathologic findings. We have classified the results of enhancement into four types as follows: (1) immediate enhancement pattern due to rich vascular bed, typical in meningiomas; (2) delayed enhancement pattern due to exudation, often seen in cystic astrocytomas; (3) intermediate sustained pattern due to both mechanisms in glioblastoma multiforme; (4) no enhancement pattern as in diffuse astrocytomas. The results of delayed enhanced CT correlated well with those of radioisotope scan.

Congenital abnormalities in newborn calves after inoculation of pregnant cows with Akabane virus

A fresh isolate of Akabane virus was inoculated intravenously into 11 seronegative pregnant cows at 62 to 96 days of gestation. Two of the cows were slaughtered 18 days post-inoculation, and the fetuses were examined; the remaining cows were allowed to give birth. All the inoculated cows developed viremia and neutralizing antibody for the virus, indicating that the cows were actually infected with the virus, although fever or any other clinical abnormalities were not noted. The virus further infected the fetuses. This was proved by virus isolation in one of the two fetuses from the slaughtered cows, and polymyositis was noted in both fetuses. Six of seven calves born alive had anti-Akabane antibody in their precolostral sera, indicating that in utero infection with the virus took place in these calves. Some of the in utero-infected calves demonstrated congenital abnormalities such as cerebral defect, hydranencephaly, and arthrogryposis. These findings provide additional evidence that Akabane virus is the etiological agent of epizootic abortion and congenital arthrogryposis-hydranencephaly syndrome in cattle.

[Indirect measurement of intracranial pressure, with special reference to its principles and experiments with animals]

A new technique for measurement of intracranial pressure was presented. By using this method a) absolute value of pressure, b) easy, simple and inexpensive long-term measurement and c) decrease in danger of infection are obtained. The apparatus consists of an external device which converts displacement of its membrane into quantitative change of beam and an internal chamber with two membranes that is implanted in a burr hole between scalp and dura mater. These devices have the same diameter and no direct connection each other. When a pressure in the external device is varied, a pressure-displacement curve of its membrane is resulted. The pressure of the external device at the point of inflexion of the curve is representative of the pressure in the internal chamber. In the animal experiment, satisfactory results were obtained.