MR visualization and clinical significance of the anterior longitudinal epidural venous plexus in cervical extra-axial lesions

A thin band of intermediate signal intensity behind the cervical vertebral bodies, demonstrated on sagittal MR images, was attributed to the anterior longitudinal epidural venous (AEVP). Percentage visualization and clinical significance of this structure were evaluated in extra-axial lesions of the spinal cord. In review of 50 normal controls, the percentage visualization of this structure at each cervical vertebral level was 25.5% on T1 weighted sagittal SE images, while that of T2 or proton density weighted SE images was 26.0%. AEVP was demonstrated by sagittal MRI in 29 of 128 extra-axial lesions of the cervical cord (22.7%), including cervical spondylosis, ossification of the posterior longitudinal ligament (PLL), herniated disk and spondylosis at a single level. AEVP in these conditions was often thickened compared with normal controls, probably due to venous engorgement and contribution of the dura mater and PLL. Posterior displacement of this structure or "lifted band appearance" indicated herniated disk or posteriorly protruding osteophyte, demonstrating true anteroposterior diameter of the spinal canal. Demonstration of AEVP on sagittal MRI was important in the diagnosis of extra-axial lesions of the cervical cord.

Increased MR signal intensity secondary to chronic cervical cord compression

Magnetic resonance images of 128 patients with compressive lesions of the cervical spinal canal were reviewed to determine whether a high signal intensity lesion within the spinal cord was present on T2 and proton density weighted spin echo images. Such high signal intensity was observed in 24 cases or 18.8%. The incidence was higher in herniated disk (32.4%), atlanto-axial dislocation (28.6%), and ossification of the posterior longitudinal ligament (22.7%), whereas the abnormality was found sporadically in cervical spondylosis and vertebral body tumors. The high intensity lesion on T2 weighted images was generally observed in patients with constriction or narrowing of the spinal cord. The lesion was not demonstrated on T1 weighted spin echo images. Spinal cord constriction or localized narrowing seemed to be the most important predisposing factor in producing such a high signal intensity. The pathophysiologic basis of such an abnormality was presumed to be myelomalacia or cord gliosis secondary to a long-standing compressive effect of the spinal cord.

Percutaneous transluminal angioplasty of the ilio-femoro-popliteal arteries: initial and long-term results

Percutaneous transluminal angioplasty has been widely used for dilatation and recanalization of occluded or stenosed vessels, but clinical experience in Japan is not extensive. Follow-ups of 78 ilio-femoro-popliteal angioplasties were performed for up to 51 months to assess the initial and long-term results. The initial technical success rate was 91%. The three-year cumulative patency rate was 75%. This study demonstrates that the long-term results of PTA of ilio-femoro-popliteal arterial lesions are competitive with reconstructive surgery. PTA should be the treatment of choice in patients with atherosclerotic narrowing or occlusion of the lower extremities.

Development of a new universal neuroangiographic unit

A new neuroangiographic unit has been developed with use of a "C" type gantry, which is capable of rotation and angulation for various angiographic projections. Two sets of a twin focal X-ray tube and an imaging system are mounted on the gantry. Each imaging system consists of a 9 inch image intensifier and a 14 X 14 rapid film changer, which can be exchanged in position rapidly. Stereoscopic magnification and stereoscopic contact angiography, fluoroscopy and DSA are performed in monoplane and biplane and switched over to each other expeditiously and easily. The detailed angiographic information is obtained with lower complication rate and lower exposure to patients. Interventional neuroradiologic procedures are performed efficiently on this unit.

Cerebral vasculitis secondary to Wegener's granulomatosis: computed tomography and angiographic findings

The central nervous system is rarely involved by Wegener's granulomatosis. A case of Wegener's granulomatosis with involvement of the cerebral arteries was reported. Computed tomography showed extensive brain edema with angiographic demonstration of cerebral vasculitis.

Stereoscopic DSA of the central nervous system

Stereoscopic DSA is performed with alternate exposures from a twin focal X-ray tube (6,5 cm focal separation). Excellent intravenous and intra-arterial DSA images of the cerebral vessels are obtained with separation of overlapping parts of the normal and abnormal vasculature. The clinical value of DSA has been enhanced by use of stereoscopic DSA.

Stereoscopic technique in digital subtraction angiography

Stereoscopic technique was applied to digital subtraction angiography (DSA) with alternate exposures from twin focus spots (6.5-cm separation) of an x-ray tube. Correct identification of two crossed aluminum wires was obtained more than 90% of the time when there was separation of more than 5 mm. Excellent clinical images of intravenous as well as intraarterial DSA have been obtained, and the clinical value of DSA was enhanced by application of the stereoscopic technique.

Diagnostic accuracy of intravenous digital subtraction angiography for peripheral vascular diseases

Intravenous digital subtraction angiography (IV DSA) was performed on 406 regions of 241 patients with peripheral vascular diseases. The results were compared with conventional angiograms for 167 arteries. There was excellent correlation between conventional angiograms and IV DSA. The diagnostic accuracy was 95 with 97% sensitivity and 94% specificity when more than 60% stenoses were taken into consideration. DSA is a less-invasive procedure which can be performed on out-patients for screening and follow-up evaluation of peripheral vascular diseases.

The effects of two physiological salines, Locke's and van Harreveld's, on the midgut red chromatophores of the freshwater shrimp, Caridina denticulata

It was reported previously that the red chromatophores on the midgut of a freshwater shrimp, Caridina denticulata, are affected by Locke's and van Harreveld's solutions differently, i.e., the pigment disperses in Locke's solution and concentrates with the addition of crude eyestalk extract, but in Harreveld's solution the chromatophores do not change in the saline alone nor do they respond to eyestalk extract. The differences were probably due to the osmotic pressure and Mg ion concentrations of the two solutions not being the same. Harreveld's solution is commonly used as a physiological saline for freshwater crustaceans such as crayfish. Consequently, this solution was employed at first in a previous study (Miyawaki and Tsuruda, 1985). But this solution completely inhibited pigment migration in the chromatophores. But when Locke's solution was subsequently tried, migration of the pigment in the midgut chromatophores occurred. It seemed worthwhile to examine further the effects of both solutions on these chromatophores. The results of this study are presented below.

Intraarterial digital subtraction angiography vs conventional angiography of abdominal diseases

Seventy-five patients with various abdominal diseases were studied by intraarterial digital subtraction angiography (IA DSA) during conventional abdominal angiographic examinations. The image quality, tumor stain, and arterial encasements were evaluated and diameters of vessels visualized by IA DSA were measured. The vessels greater than 2.0 mm or more in diameter were equally well demonstrated on IA DSA. IA DSA demonstrated tumor stains and portal system to good advantage. Real time imaging was also advantageous during an embolization procedure.

The structure and function of the hepatopancreas of a terrestrial isopod, Armadillidium vulgare

The fine structure of the hepatopancreas of the isopod, Armadillidium vulgare was studied in intact and in experimentally treated animals. The gross anatomy of the hepatopancreas of this species is simpler than that of decapods, but microscopically the cells are similar in both. Accordingly, the function of this organ is probably the same in decapods and Armadillidium. Some phylogenetic considerations are also presented. In a previous paper Miyawaki et al. (1984), presented experimental results which indicated that the hepatopancreas of the crayfish, Procambarus clarki, had an important role in the absorption of digested food materials. These results confirmed earlier reports by Yonge (1924) and van Weel (1955) on the decapods, Nephrops norvegicus and Atya spinides, respectively. In the present study, we wished to determine whether the isopod hepatopancreas has a function like that of the decapods. A terrestrial isopod, Armadillidium vulgare collected on the University campus, and reared in the laboratory at room temperature was used. The methods of study were similar to those employed in the study with Procambarus clarki (Miyawaki et al., 1984).

Absorption of experimentally administered materials by the hepatopancreas cells of the crayfish, Procambarus clarki

After long term starvation, the crayfish, Procambarus clarki was administered protein silver, iron lactate and olive oil, and its hepatopancreas was subsequently examined by electron microscopy. The reserve cells showed changes suggesting the absorption of these materials from the acinar lumen had taken place. In contrast, the hindgut of crayfish seemed to have no absorptive ability. In crustaceans the hepatopancreas is the largest gland in the body. The chief functions of this gland are the secretion of digestive juice into the stomach and absorption of digested food. It is also where materials which are necessary for hardening of animals that have undergone ecdysis are stored. Although these roles are commonly accepted, the absorptive ability of the gland has been rarely studied. Yonge (1924) and van Weel (1955) attempted to obtain evidence for the absorptive function of hepatopancreas cells of Nephrops norvegicus and Atya spinides using iron lactate and iron saccharate, and obtained some positive results. They used the histochemical Prussian blue test to demonstrate absorbed iron. Vonk (1960) referred to the results of a few authors who had tried to show fat deposits in reserve cells of the hepatopancreas after the administration of olive oil to the animals. But because starvation did not affect the quantity of stored fat in the hepatopancreas cells, the attempt failed to reveal the absorption of fat by the hepatopancreas. In the present paper, the authors describe the results of studies on the absorption of experimentally administered materials by hepatopancreas cells of the crayfish, Procambarus clarki, using electron microscopy.

The microvilli of the midgut epithelium in the freshwater shrimp, Caridina denticulata

The ultrastructure of the epithelial cell microvilli of the midgut of a decapod, Caridina denticulata , was studied. The microvilli have an axial bundle of filaments extend from the tip of the microvilli deeply into the interior cytoplasm of the epithelial cells. Basal globules were present at the base of the microvilli in the premolt stage animals. The length and arrangement of the microvilli change during the molting cycle.

The value of digital subtraction angiography in peripheral vascular diseases

The iliac and subclavian arteries and their distal branches were studied by digital subtraction angiography (DSA) in 79 patients and the results compared with conventional angiograms for 35 patients. Techniques, results, advantages and disadvantages are described. DSA (both intravenous and intra-arterial) looks very promising in the diagnosis of peripheral vascular disease.

Evaluation of prototype equipment for digital subtraction angiography in diagnosing intracranial lesions

Two prototype units for digital subtraction angiography have been developed by Japanese manufacturers. Their performance in demonstrating various intracranial lesions in 121 patients was evaluated. Comparison with conventional selective catheter angiography was possible in 77 patients. Digital subtraction angiography proved useful in preoperative evaluation of pituitary tumors when transsphenoidal surgery was being considered; demonstration of faint tumor stains which might be missed on conventional angiography; demonstration of larger aneurysms, arteriovenous malformations, and tumors as a screening technique; demonstration of abnormalities involving the dural sinuses; and follow-up of patients after surgery or embolization.