Evaluation of the Skull Base on Axial CT Slices in a Craniocaudal Sequence

2011 ◽  
Keyword(s):  
Skull Base ◽  
Axial Ct ◽  
Ct Slices

Axial Configuration of the Velopharyngeal Valve and Its Valving Mechanism

1995 ◽  
Vol 32 (4) ◽  
pp. 299-305 ◽  
Author(s):  
Yehuda Finkelstein ◽  
Myra Shapiro-Feinberg ◽  
Yoav P. Talmi ◽  
Ariela Nachmani ◽  
Ari Derowe ◽  
...  
Keyword(s):  
Skull Base ◽  
Ct Scans ◽  
Closure Mechanism ◽  
Axial Ct ◽  
Pattern Variability

The variability of the normal velopharyngeal (VP) closure mechanism was studied by investigating VP anatomy in relation to its closure mechanism in 60 patients. The axial configuration of the VP isthmus, as observed in axial CT scans at rest, was found to be correlated with VP function in terms of its closure patterns in speech as observed by nasendoscopy. A flat VP isthmus was found to be closed mainly in the anteroposterior direction, forming the coronal closure pattern. A deep VP isthmus is closed by movement of the velum and medial movement of the lateral pharyngeal walls, forming the circular closure pattern. A flat VP isthmus occurs when the hamuli are posteriorly located and the muscular slings, therefore, open more posteriorly. We conclude that posterior insertion of the velar muscles on to the skull base results in a flatter, larger VP axial configuration, whereas an anterior insertion results in a VP axial configuration that is deeper and less flat. A flat VP isthmus contracts mainly in an anteroposterior direction, exhibiting a coronal closure pattern, while a deep or round VP isthmus contracts centripetally, exhibiting a circular closure pattern. Variability of the VP valving mechanism is of anatomic and not of functional origin.

Comparing axial CT slices in quantized N-dimensional SURF descriptor space to estimate the visible body region

2011 ◽  
Vol 35 (3) ◽  
pp. 227-236 ◽  
Author(s):  
Johannes Feulner ◽  
S.Kevin Zhou ◽  
Elli Angelopoulou ◽  
Sascha Seifert ◽  
Alexander Cavallaro ◽  
...  
Keyword(s):  
Body Region ◽  
Descriptor Space ◽  
Axial Ct ◽  
Ct Slices ◽  
Visible Body

CT Artifacts of the Proximal Aortic Neck: An Important Problem in Endograft Planning

2002 ◽  
Vol 9 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Boonprasit Kritpracha ◽  
Jeremy Wolfe ◽  
Hugh G. Beebe
Keyword(s):  
Statistical Significance ◽  
Three Dimensional ◽  
Vessel Diameter ◽  
Maximum Diameter ◽  
Computed Tomographic ◽  
Aortic Neck ◽  
Preoperative Ct ◽  
Axial Ct ◽  
Ct Slices ◽  
Reformatted Ct

Purpose: To describe the imaging error introduced by noncircular abdominal aortic aneurysm (AAA) necks in axial and reformatted computed tomographic (CT) images and discuss the potential implications for aortic endografting. Methods: The records of 120 endograft patients with preoperative CT axial scans and subsequent 3-dimensional (3D) computerized reconstructions were reviewed. Maximum and minimum infrarenal aortic neck diameters were measured from axial CT scans and 3D reformatted slices at the same point on the vessel. Diameter measurements were made at the largest point within the 10-mm segment of vessel below the lowest renal artery. Excluded were aneurysms with proximal neck minimum diameters >30 mm, neck lengths <15 mm, or angulation >75° measured on the axial CT slice. Results: Measuring from reformatted CT slices, 86 (71.6%) cases had ≤2-mm differences between maximal and minimal neck diameters, comprising the “round neck” group A. In 34 (28.4%) cases, the neck was not round: 26 (21.7%) had diameter differences between 2 and 4 mm (group B) and 8 (6.7%) had a >4-mm difference (group C; range 4.1–8.1 mm). Although AAA diameter, neck length, and neck angle progressively increased as the difference between neck maximum and minimum diameters grew, i.e., greater eccentricity, these trends did not reach statistical significance. Mean infrarenal neck maximum diameter was significantly larger in group C (30.2 ± 3.4 mm) compared to groups A (23.0 ± 2.9 mm, p = 0.0002) and B (23.8 ± 3.6 mm, p = 0.0003). Hence, 28.4% of AAAs had a noncircular aortic neck of varying degree, and 6.7% had an eccentricity factor that may have clinical significance. Conclusions: This study confirms the importance of selecting an endoprosthesis sized 15% to 20% larger than the infrarenal aortic neck diameter. Three-dimensional reconstruction using reformatted CT slices perpendicular to the flow lumen is an important tool that offers enhanced accuracy of infrarenal aortic neck evaluation.

scholarly journals The accuracy of multi-slice three-dimensional computerized tomography on the verification of the pedicle screw trajectory

2009 ◽  
Vol 1 (1) ◽  
pp. 22
Author(s):  
Suat Erol Çelik ◽  
Bilal Kelten ◽  
Recai Gökcan ◽  
Ahmet Cevri Yıldız
Keyword(s):  
Pedicle Screw ◽  
Computerized Tomography ◽  
Spinal Surgery ◽  
Three Dimensional ◽  
Pedicle Screws ◽  
Ct Reconstruction ◽  
Axial Ct ◽  
Diagnostic Power ◽  
Ct Slices

The purpose of our study was to determine the diagnostic power of three-dimensional reformatted multi-slice computerized tomography (CT) images on misplaced pedicle screws in spinal surgery. Eighty-four consecutive patients with 458 screws in situ were investigated prospectively using both axial CT slices and reformatted images after operation by two blinded investigators. All the screw misplacements were documented and the differences between the two imaging modalities were recorded. Axial CT slices were able to show only 23 of 60 misplaced pedicle screws; multi-slice CT was three times more powerful in the diagnosis of pedicle screw complications in spinal surgery (p<0.05). We concluded that multi-slice CT reconstruction should be the primary diagnostic tool after screw implantation in the human spine.

scholarly journals 3D-CT vascular setting protocol using computer graphics for the evaluation of maxillofacial lesions

2001 ◽  
Vol 15 (3) ◽  
pp. 229-236 ◽  
Author(s):  
Marcelo de Gusmão Paraiso CAVALCANTI ◽  
Axel RUPRECHT ◽  
Michael Walter VANNIER
Keyword(s):  
Computer Graphics ◽  
Three Dimensional ◽  
3D Ct ◽  
3D Images ◽  
Quantitative Analyses ◽  
Axial Ct ◽  
Interactive 3D ◽  
Ct Slices

In this paper we present the aspect of a mandibular giant cell granuloma in spiral computed tomography-based three-dimensional (3D-CT) reconstructed images using computer graphics, and demonstrate the importance of the vascular protocol in permitting better diagnosis, visualization and determination of the dimensions of the lesion. We analyzed 21 patients with maxillofacial lesions of neoplastic and proliferative origins. Two oral and maxillofacial radiologists analyzed the images. The usefulness of interactive 3D images reconstructed by means of computer graphics, especially using a vascular setting protocol for qualitative and quantitative analyses for the diagnosis, determination of the extent of lesions, treatment planning and follow-up, was demonstrated. The technique is an important adjunct to the evaluation of lesions in relation to axial CT slices and 3D-CT bone images.

Sign in / Sign up

Export Citation Format

Share Document