scholarly journals Giant high occipital encephalocele

2016 ◽  
Vol 30 (1) ◽  
pp. 122-126
Author(s):  
Amit Agrawal ◽  
Reddy V. Umamaheshwara ◽  
Kishor V. Hegde ◽  
P. Suneetha ◽  
Divya Siddharth Kolikipudi
Keyword(s):  
Ct Images ◽  
Foramen Magnum ◽  
Defect Size ◽  
Occipital Bone ◽  
Developmental Anomalies ◽  
Occipital Encephalocele ◽  
Adjacent Structures ◽  
Vascular Structures ◽  
Osseous Defect ◽  
Ct And Mri

Abstract Encephaloceles are rare embryological mesenchymal developmental anomalies resulting from inappropriate ossification in skull through with herniation of intracranial contents of the sac. Encephaloceles are classified based on location of the osseous defect and contents of sac. Convexity encephalocele with osseous defect in occipital bone is called occipital encephalocele. Giant occipital encephaloceles can be sometimes larger than the size of baby skull itself and they pose a great surgical challenge. Occipital encephaloceles (OE) are further classified as high OE when defect is only in occipital bone above the foramen magnum, low OE when involving occipital bone and foramen magnum and occipito-cervical when there involvement of occipital bone, foramen magnum and posterior upper neural arches. Chiari III malformation can be associated with high or low occipital encephaloceles. Pre-operatively, it is essential to know the size of the sac, contents of the sac, relation to the adjacent structures, presence or absence of venous sinuses/vascular structures and osseous defect size. Sometimes it becomes imperative to perform both CT and MRI for the necessary information. Volume rendered CT images can depict the relation of osseous defect to foramen magnum and provide information about upper neural arches which is necessary in classifying these lesions.

scholarly journals A deep learning method for automatic segmentation of the bony orbit in MRI and CT images

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jared Hamwood ◽  
Beat Schmutz ◽  
Michael J. Collins ◽  
Mark C. Allenby ◽  
David Alonso-Caneiro
Keyword(s):  
Deep Learning ◽  
Human Performance ◽  
Automatic Segmentation ◽  
Ct Images ◽  
Human Observer ◽  
In Series ◽  
Magnetic Resonance Imaging Mri ◽  
High Degree ◽  
Orbital Region ◽  
Ct And Mri

AbstractThis paper proposes a fully automatic method to segment the inner boundary of the bony orbit in two different image modalities: magnetic resonance imaging (MRI) and computed tomography (CT). The method, based on a deep learning architecture, uses two fully convolutional neural networks in series followed by a graph-search method to generate a boundary for the orbit. When compared to human performance for segmentation of both CT and MRI data, the proposed method achieves high Dice coefficients on both orbit and background, with scores of 0.813 and 0.975 in CT images and 0.930 and 0.995 in MRI images, showing a high degree of agreement with a manual segmentation by a human expert. Given the volumetric characteristics of these imaging modalities and the complexity and time-consuming nature of the segmentation of the orbital region in the human skull, it is often impractical to manually segment these images. Thus, the proposed method provides a valid clinical and research tool that performs similarly to the human observer.

scholarly journals Morphometrical Study of the Lumbar Segment of the Internal Vertebral Venous Plexus in Dogs: A Contrast CT-Based Study

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1502
Author(s):  
Valeria Ariete ◽  
Natalia Barnert ◽  
Marcelo Gómez ◽  
Marcelo Mieres ◽  
Bárbara Pérez ◽  
...  
Keyword(s):  
Epidural Space ◽  
Ct Images ◽  
Venous Plexus ◽  
Morphological Pattern ◽  
Vertebral Canal ◽  
Dural Sac ◽  
Internal Vertebral Venous Plexus ◽  
Adjacent Structures ◽  
Contrast Ct ◽  
Enhanced Computed Tomography

The internal vertebral venous plexus (IVVP) is a thin-walled, valveless venous network that is located inside the vertebral canal, communicating with the cerebral venous sinuses. The objective of this study was to perform a morphometric analysis of the IVVP, dural sac, epidural space and vertebral canal between the L1 and L7 vertebrae with contrast-enhanced computed tomography (CT). Six clinically healthy adult dogs weighing between 12 kg to 28 kg were used in the study. The CT venographic protocol consisted of a manual injection of 880 mgI/kg of contrast agent (587 mgI/kg in a bolus and 293 mgI/mL by continuous infusion). In all CT images, the dimensions of the IVVP, dural sac, and vertebral canal were collected. Dorsal reconstruction CT images showed a continuous rhomboidal morphological pattern for the IVVP. The dural sac was observed as a rounded isodense structure throughout the vertebral canal. The average area of the IVVP ranged from 0.61 to 0.74 mm2 between L1 and L7 vertebrae (6.3–8.9% of the vertebral canal), and the area of the dural sac was between 1.22 and 7.42 mm2 (13.8–72.2% of the vertebral canal). The area of the epidural space between L1 and L7 ranged from 2.85 to 7.78 mm2 (27.8–86.2% of the vertebral canal). This CT venography protocol is a safe method that allows adequate visualization and morphometric evaluation of the IVVP and adjacent structures.

scholarly journals Foramen Magnum Stenosis in Achondroplasia

2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Choayb S ◽  
◽  
Adil H ◽  
El Haddad S ◽  
◽  
...  
Keyword(s):  
Sudden Death ◽  
Skull Base ◽  
Short Stature ◽  
Skeletal Dysplasia ◽  
Endochondral Ossification ◽  
Foramen Magnum ◽  
Severe Complication ◽  
Occipital Bone ◽  
Severe Morbidity ◽  
Cervicomedullary Junction

Achondroplasia is the most common hereditary skeletal dysplasia and is characterized by disproportionately short stature with rhizomelic short extremities [1]. The skull features include a narrowed foramen magnum, short skull base, and clivus [2]. Foramen magnum stenosis is a characteristic funding, secondary to an abnormal placement and premature fusion of the posterior synchondroses [1]. The second factor responsible for stenosis is a defect in endochondral ossification in the basiocciput that may result in an extension of the squamous occipital bone [2]. It can cause hydrocephalus and prominent emissary and meningeal veins (Figure 1). Figure 1: Sagittal T1WI revealing a narrowed stenosis of the foramen magnum and compression of the cervicomedullary junction. The most severe complication is the compression of the cervicomedullary junction, associated with severe morbidity and sudden death in younger children [1].

scholarly journals Morphologic and Osteometric Analysis of the Skull of Markhoz Goat (Iranian Angora)

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Nader Goodarzi ◽  
Toraj Shah Hoseini
Keyword(s):  
Foramen Magnum ◽  
Parietal Bone ◽  
Frontal Bone ◽  
Occipital Bone ◽  
Cheek Tooth ◽  
Frontal Surface ◽  
Infraorbital Foramen ◽  
Skull Length ◽  
Cranial Index

This study provides some comprehensive osteometric and morphologic descriptions of the skull region of the Markhoz goat. Totally, 17 osteometric parameters of eight skulls of Markhoz goat were measured and expressed as mean ± SD. A skull length of18.67±0.66, a cranial length of11.1±0.38, a facial length of10.23±0.76, a skull index of47.77±1.96, a cranial index of54.04±2.29, a facial index of100.77±6.85and a foramen magnum index of89.32±14.1were recorded. Morphologically frontal bone did not constitute the caudal extent of frontal surface; rather it was formed by the parietal bone. There were two supraorbital foramina in both sides. The prominent facial tuberosity lies dorsally to the 3rd cheek tooth. The infraorbital foramen was single on either side which was located directly dorsally to the junction of the first and second upper premolar. The orbits were round and complete and located on a frontolateral oblique plane. The basilar part of the occipital bone was surrounded by two pairs of muscular tubercles with similar size. The temporal line was continuous of the temporal crest and ran over the parietal bone. In conclusion, the morphologic and osteometric data of Markhoz goat are comparable to other ruminants.

How much intravenous contrast is needed in FDG-PET/CT?

2005 ◽  
Vol 44 (S 01) ◽  
pp. S32-S37 ◽  
Author(s):  
K. Strobel ◽  
C. M. Thuerl ◽  
T. F. Hany
Keyword(s):  
Fdg Pet ◽  
Tumour Invasion ◽  
Intravenous Contrast ◽  
Iodinated Contrast ◽  
Adjacent Structures ◽  
Pet Ct ◽  
Vascular Structures ◽  
Fdg Pet Ct ◽  
Unnecessary Radiation

Summary:Intravenous, iodinated contrast agents are used routinely for CT (ceCT) imaging but only applied reluctantly for FDGPET/ CT due to possible artefacts. Only for few oncological PET/CT indications, the role of IV contrast agent has been clarified. Essentially, if any knowledge regarding vascular structures or tumour invasion into adjacent structures are needed, a ceCT as part of the combined PET/CT exam should be implemented. However, for some indications like lymphoma, contrast seems not to be necessary. Therefore, imaging procedures for the use of IV contrast for PET/CT have to be adapted individually for each FDG-PET/CT indication to especially reduce unnecessary radiation burden to the patient.

scholarly journals Magnetic resonance imaging and computed tomography of equine cheek teeth and adjacent structures: comparative study of image quality in horses in vivo, post-mortem and frozen-thawed

2019 ◽  
Vol 61 (1) ◽  
Author(s):  
Christin Röttiger ◽  
Maren Hellige ◽  
Bernhard Ohnesorge ◽  
Astrid Bienert-Zeit
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Post Mortem ◽  
Mr Images ◽  
Adjacent Structures ◽  
Group A ◽  
Group B ◽  
The Impact ◽  
Ct And Mri

Abstract Background The use of cadavers for radiology research methodologies involving subjective image quality evaluation of anatomical criteria is well-documented. The purpose of this method comparison study was to evaluate the image quality of dental and adjacent structures in computed tomography (CT) and high-field (3 T) magnetic resonance (MR) images in cadaveric heads, based on an objective four-point rating scale. Whilst CT is a well-established technique, MR imaging (MRI) is rarely used for equine dental diagnostics. The use of a grading system in this study allowed an objective assessment of CT and MRI advantages in portraying equine cheek teeth. As imaging is commonly performed with cadaveric or frozen and thawed heads for dental research investigations, the second objective was to quantify the impact of the specimens’ conditions (in vivo, post-mortem, frozen-thawed) on the image quality in CT and MRI. Results The CT and MR images of nine horses, focused on the maxillary premolar 08s and molar 09s, were acquired post-mortem (Group A). Three observers scored the dental and adjacent tissues. Results showed that MR sequences gave an excellent depiction of endo- and periodontal structures, whereas CT produced high-quality images of the hard tooth and bony tissues. Additional CT and MRI was performed in vivo (Group B) and frozen-thawed (Group C) in three of these nine horses to specify the condition of the best specimens for further research. Assessing the impact of the specimens’ conditions on image quality, specific soft tissues of the maxillary 08s and 09s including adjacent structures (pulps, mucosa of the maxillary sinuses, periodontal ligament, soft tissue inside the infraorbital canal) were graded in group B and C and analysed for significant differences within CT and MR modalities in comparison to group A. Results showed that MRI scores in vivo were superior to the post-mortem and frozen-thawed condition. Conclusions On comparing the imaging performance of CT and MRI, both techniques show a huge potential for application in equine dentistry. Further studies are needed to assess the clinical suitability of MRI. For further research investigations it must be considered, that the best MR image quality is provided in live horses.

scholarly journals Interobserver and intraobserver comparison of imaging glenoid morphology, glenoid version and humeral head subluxation

2018 ◽  
Vol 11 (3) ◽  
pp. 204-209 ◽  
Author(s):  
Paul J Cagle ◽  
Birgit Werner ◽  
Dave R Shukla ◽  
Daniel A London ◽  
Bradford O Parsons ◽  
...  
Keyword(s):  
Humeral Head ◽  
Interobserver Agreement ◽  
Weighted Kappa ◽  
Similar Efficacy ◽  
Ct Images ◽  
Glenoid Version ◽  
Kappa Value ◽  
Glenoid Morphology ◽  
Magnetic Resonance Imaging Mri ◽  
Ct And Mri

Background Glenoid morphology, glenoid version and humeral head subluxation represent important parameters for the treating physician. The most common method of assessing glenoid morphology is the Walch classification which has only been validated with computed tomography (CT). Methods CT images and magnetic resonance imaging (MRI) images of 25 patients were de-identified and randomized. Three reviewers assessed the images for each parameter twice. The Walch classification was assessed with a weighted kappa value. Glenoid version and humeral head subluxation were comparted with a reproducibility coefficient. Results The Walch classification demonstrated almost perfect intraobserver agreement for MRI and CT images (k = 0.87). Weighted interobserver agreement values for the Walch classification were fair for CT and MRI (k = 0.34). The weighted reproducibility coefficient for glenoid version measured 9.13 (CI 7.16–12.60) degrees for CT and 13.44 (CI 10.54–18.55) degrees for MRI images. The weighted reproducibility coefficient for percentage of humeral head subluxation was 17.43% (CI 13.67–24.06) for CT and 18.49% (CI 14.5–25.52) for MRI images. Discussion CT and MRI images demonstrated similar efficacy in classifying glenoid morphology, measuring glenoid version and measuring posterior humeral head subluxation. MRI can be used as an alternative to CT for measuring these parameters.

scholarly journals Quantitive Study on Some Aspect of Occipital Area in Domestic Cat (Felis catus)

2016 ◽  
pp. 18-21 ◽  
Author(s):  
M Uddin ◽  
ME Hossain ◽  
MS Islam ◽  
MB Hossain ◽  
KN Islam
Keyword(s):  
Foramen Magnum ◽  
Felis Catus ◽  
Occipital Bone ◽  
Domestic Cat ◽  
Clinical Anatomy ◽  
Significant Difference ◽  
The Mean ◽  
Level Of Significance ◽  
Occipital Condyles ◽  
Classification And Treatment

This study was planned to investigate some aspects of the morphometric characteristics of the occipital bone and foramen megnum in domestic cat (Felis catus). Twenty adult domestic cat including 10 males and 10 female cats were euthanized using diazepam (@ 20 mg/kg) and their skulls were macerated to give morphometric parameters. Student t-test with level of significance set at 5% (p < 0.05) was used to analyze the obtained values. The height of occipital triangle, width of occipital condyles, width of jugular process were significantly larger in male than female. The mean height and width of the foramen magnum were 1.32 ± 0.09 cm and 1.35 ± 0.08 cm, respectively, while the foramen index was below 100 at 90.72 ± 4.93. Parameters for the foramen magnum index showed significant difference between both sexes at p < 0.05. The foramen magnum showed shape variations and there were multiple hypoglossal foramina in over 80% of the cats. The morphometric values of the occipital bone and foramen magnum and clinical anatomy of the occipital region of the domestic cats provide an important baseline for further research in this field and could help in the better diagnosis, classification, and treatment of diseases related to this region and serve as a future reference defining an anatomic range.International Journal of Natural Sciences (2013), 3(1-4) 18-21

Two-year-old girl with cervicomedullary junction stenosis and an unknown type of skeletal dysplasia

2008 ◽  
Vol 2 (3) ◽  
pp. 200-202
Author(s):  
Samuel Henry Cheshier ◽  
Mohammad Yashar Sorena Kalani ◽  
Arjun Pendakaur ◽  
Dominique Higgins ◽  
David Kahn ◽  
...  
Keyword(s):  
Skeletal Dysplasia ◽  
Cranial Nerve ◽  
Cranial Nerve Palsy ◽  
Nerve Palsy ◽  
Foramen Magnum ◽  
Occipital Bone ◽  
Lower Cranial Nerve ◽  
Unknown Type ◽  
Cervicomedullary Junction ◽  
Lower Cranial Nerve Palsy

The authors present a novel case of skeletal dysplasia in a 2.8-year-old girl. The patient presented with progressive lower cranial nerve palsy and myelopathy due to constriction at the cervicomedullary junction caused by overgrowth of the occipital bone of the foramen magnum and the C-1. She also had prominent bone overgrowth of the superior orbital ridges, resulting in excessive stretching of periorbital skin and an inability to fully close her eyes.

Segmentation of the heart and major vascular structures in cardiovascular CT images

2008 ◽  
Author(s):  
J. Peters ◽  
O. Ecabert ◽  
C. Lorenz ◽  
J. von Berg ◽  
M. J. Walker ◽  
...  
Keyword(s):  
Ct Images ◽  
Vascular Structures ◽  
Cardiovascular Ct
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