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Biomedical subjects

C Virapongse

Publications and source records attributed to C Virapongse.

61 records · Page 4Linked to original sources
PubMedDate not supplied

Experimental production of superior sagittal sinus thrombosis in the dog.

Prior efforts at experimental production of superior sagittal sinus (SSS) thrombosis generally have been unsuccessful. An experimental method was devised of inducing SSS thrombosis in the dog by use of double-lumen balloon catheters. Two balloon catheters, introduced into each internal jugular vein, are finally positioned at the torcular Herophili. The resulting stasis in the SSS, initiated by the inflated balloons, is augmented by injecting thrombin into the SSS. The stasis and the intraluminal thrombin cause thrombosis, which can be visualized on computed tomography (CT). This method may be used to study the natural history of SSS thrombosis as well as establish its CT and magnetic resonance imaging characteristics.

Animals↗
PubMedDate not supplied

Computed tomography of temporal bone pneumatization: 2. Petrosquamosal suture and septum.

The degree of visualization of the petrosquamosal (Körner's) septum on high-resolution axial computed tomography (CT) in 141 temporal bones (100 subjects) was analyzed. The superior and inferior parts of the septum were assessed separately and were seen in 75% and 41% of cases, respectively. There was no relation between the size of Körner's septum and pneumatization. The clinical relevance of this finding is discussed. The CT features of the ventral petrosquamosal suture also were investigated. The crista tegmentalis, a contribution of the petrosal tegmen to the mandibular fossa, was seen on CT as a polypoid excrescence projecting from the ventrolateral petrous pyramid. This knowledge is useful in the radiographic analysis of the course of longitudinal fractures of the petrous bone.

Cranial Sutures↗
PubMedDate not supplied

Experimental cord stretchability and the tethered cord syndrome.

Much remains to be learned about the embryology and pathophysiology of the "tethered cord syndrome." Of particular importance in tethered cord syndrome is spinal cord stretchability and its relation to resultant cord dysfunction. In this study, cord elongation was observed in fresh fetuses and in animals by applying weights or forceps traction at the conus medullariscauda equina region. The results show that maximum cord elongation occurs in the lumbar region, some occurs in the thoracic area, and minimal to no elongation occurs in the cervical region. These results are concordant with clinically observed lumbosacral cord dysfunction and oxidative and electrophysiologic impairment of the lumbosacral cord in tethered cord syndrome as shown by other investigators.

Animals↗
PubMedDate not supplied

Skull phylogeny: an investigation using radiography and high-resolution computed tomography.

To demonstrate the phylogenetic changes that have led to the current form of the human skull, dried skulls of various representative vertebrates were examined using plain radiography and high-resolution computed tomography. The latter was chosen rather than pluridirectional tomography in anticipation of its future role as the major method for imaging the skull base. The phylogenetic history of the human skull is reviewed by considering separately the evolution of the calvarium, zygomatic arch, palate, jaw, and skull base.

Anatomy, Comparative↗
PubMedDate not supplied

Primary tethered cord syndrome: a new hypothesis of its origin.

Primary tethered cord syndrome is defined as low placement of the spinal cord and thickened filum terminale with associated anomalies. This definition excludes anomalies concomitant with overt myelomeningocele and spinal cord tethering secondary to myelomeningocele repair. Embryologically, the primary tethered cord syndrome is an entirely different entity from overt myelomeningocele and associated Arnold-Chiari type II malformation, but its origins have not been satisfactorily explained. The authors postulate that primary tethered cord syndrome is a manifestation of local dysmorphogenesis of all three germ layers at the lumbosacral area, possibly triggered by a hemorrhagic, inflammatory, or some other local lesion occurring in embryogenesis.

Animals↗
PubMedDate not supplied

High-resolution computed tomographic appearance of normal cochlear aqueduct.

Computed tomographic (CT) scans of 37 patients with normal adult cochlear aqueducts were selected for retrospective analysis. Usually, only the inferomedial part of the cochlear aqueduct could be seen on axial CT. The sizes of the external cochlear aqueduct opening were tabulated, and they did not vary significantly with age or gender. The average width was 2.9 mm. Of the configurations found, the most common was the funnel (22 cases).

Adolescent↗