Introducing the posterior condylar emissary vein as an effective surgical landmark for optimizing the standard retrosigmoid approach. An anatomo-imaging study.

ABSTRACT Purpose: We assessed the prevalence of the clinically important posterior fossa emissary veins detected on computed tomography (CT) angiography. Materials and Methods: A total of 182 consecutive patients who underwent 64-slice CT angiography were retrospectively reviewed to determine the clinically important posterior fossa emissary veins. Results: Of 166 patients, the mastoid emissary vein (MEV) was not identified in 37 (22.3%) patients. It was found bilaterally in 82 (49.4%) and unilaterally in 47 (28.3%) patients. Only six patients had more than one MEV that were very small (<2 mm), and only five patients had very large (>5 mm) veins. The posterior condylar vein (PCV) was not identified in 39 (23.5%) patients. It was found bilaterally in 97 (58.4%) and unilaterally in 30 (18.1%) patients. Only 15 patients had a very large (>5 mm) PCV. The petrosquamosal sinus (PSS) was identified only in one patient (0.6%) on the left side. The occipital sinus was found in two patients (1.2%). Conclusions: The presence of the clinically important posterior fossa emissary veins is not rare. Posterior fossa emissary veins should be identified and systematically reported, especially prior to surgeries involving the posterior fossa and mastoid region.

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Posterior Condylar Cartilage Thickness and Posterior Condylar Offset of the Femur: A Magnetic Resonance Imaging Study

Journal of Orthopaedic Surgery ◽

10.1177/230949901602400105 ◽

2016 ◽

Vol 24 (1) ◽

pp. 12-15 ◽

Cited By ~ 5

Author(s):

Gregory C Wernecke ◽

Bradley G Seeto ◽

Darren B Chen ◽

Samuel J MacDessi

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Imaging Study ◽

Cartilage Thickness ◽

Magnetic Resonance Imaging Study ◽

Resonance Imaging ◽

Condylar Cartilage ◽

Posterior Condylar Offset ◽

Posterior Condylar

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High resolution STEM imaging study on high Tc superconductor YBa2CuaO7-x

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100106478 ◽

1988 ◽

Vol 46 ◽

pp. 882-883

Author(s):

H.-J. Ou ◽

J. M. Cowley

Keyword(s):

Crystal Structure ◽

High Resolution ◽

Grain Boundary ◽

Strong Field ◽

Imaging Study ◽

Structure Defects ◽

High Tc ◽

High Tc Superconductor ◽

Diffraction Patterns ◽

Lattice Planes

Using the dedicate VG-HB5 STEM microscope, the crystal structure of high Tc superconductor of YBa2Cu3O7-x has been studied via high resolution STEM (HRSTEM) imaging and nanobeam (∽3A) diffraction patterns. Figure 1(a) and 2(a) illustrate the HRSTEM image taken at 10' times magnification along [001] direction and [100] direction, respectively. In figure 1(a), a grain boundary with strong field contrast is seen between two crystal regions A and B. The grain boundary appears to be parallel to a (110) plane, although it is not possible to determine [100] and [001] axes as it is in other regions which contain twin planes [3]. Following the horizontal lattice lines, from left to right across the grain boundary, a lattice bending of ∽4° is noticed. Three extra lattice planes, indicated by arrows, were found to terminate at the grain boundary and form dislocations. It is believed that due to different chemical composition, such structure defects occur during crystal growth. No bending is observed along the vertical lattice lines.

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