Morphometric Analysis of the Foramen Magnum

Neurosurgery ◽  
2010 ◽  
Vol 66 (2) ◽  
pp. 385-388 ◽  
Author(s):  
R. Shane Tubbs ◽  
Christoph J. Griessenauer ◽  
Marios Loukas ◽  
Mohammadali M. Shoja ◽  
Aaron A. Cohen-Gadol
Keyword(s):  
Surface Area ◽  
Foramen Magnum ◽  
Morphometric Study ◽  
Computer Assisted ◽  
Type I ◽  
Image Analysis System ◽  
Surface Areas ◽  
Size Type ◽  
The Mean ◽  
Analysis System

Abstract OBJECTIVE To further elucidate the importance of anatomic variations in morphology of the foramen magnum and associated clinical implications, we conducted a morphometric study. METHODS Seventy-two dry skulls were used for this study. Digital images were obtained of the foramen magnum from an inferior view. These images were studied using a computer-assisted image analysis system. Next, an image processor was used to calculate pixel differences between 2 selected points, which allowed accurate translation of pixel differences into metric measurements. RESULTS We found that the mean surface area of the foramen magnum was 558 mm2, the mean anteroposterior diameter was 3.1 cm, and the mean horizontal diameter was 2.7 cm. For comparison, surface areas were classified into 3 types based on size. Type I foramina were identified in 20.8% of the dry skulls (15 skulls) and exhibited a surface area of less than 500 mm2. Type II (66.6%, 48 skulls) was applied to foramina of an intermediate size with surface areas ranging between 500 to 600 mm2. Type III (12.5%, 9 skulls) was applied to large foramina with surface areas of more than 600 mm2. CONCLUSION These data may be of use as a morphometric database for description of “normal” variants of foramen magnum morphology.

Incidence of basioccipital hypoplasia in Chiari malformation Type I: comparative morphometric study of the posterior cranial fossa

2009 ◽  
Vol 111 (5) ◽  
pp. 1046-1052 ◽  
Author(s):  
Rémy Noudel ◽  
Nicolas Jovenin ◽  
Cristophe Eap ◽  
Bernard Scherpereel ◽  
Laurent Pierot ◽  
...  
Keyword(s):  
Chiari Malformation ◽  
Foramen Magnum ◽  
Posterior Cranial Fossa ◽  
Morphometric Study ◽  
Control Group ◽  
Type I ◽  
Chiari Malformation Type I ◽  
Cranial Fossa ◽  
The Mean ◽  
Sphenooccipital Synchondrosis

Object The chronic tonsillar herniation defining Chiari malformation Type I (CMI) is thought to result from overcrowding of a normally developing hindbrain within a congenitally small posterior cranial fossa (PCF) due to occipital hypoplasia. The goals in the present study were to authenticate the cranioencephalic disproportion in a group of patients with CMI and to discuss new developmental aspects according to which part of the occipital bone was underdeveloped. Methods The authors retrospectively examined a group of 17 patients with CMI. Measurements of osteotentorial and neural structures of the PCF were made on MR images of the brain. The results were compared with findings in 30 healthy controls by using the Mann-Whitney U-test. Results Dimensions of the neural structures did not differ between the 2 groups of patients. The mean length of the basiocciput was significantly shorter in the CMI group (19.4 mm) compared with the control group (25.7 mm; p = 0.0003). The mean diameter of the foramen magnum was larger in the CMI group, but this difference was not statistically significant. The dimensions of the supraocciput and the mean angle of the cerebellar tentorium were identical in the 2 groups. Conclusions Data in this study support the idea that occipital hypoplasia is the main cause of overcrowding within the PCF. Basioccipital shortness is a cardinal feature of the resultant shallow PCF and could proceed from a congenital disorder of the cephalic mesoderm of the parachordal plate or occur later in the infancy because of premature stenosis of the sphenooccipital synchondrosis.

Complete posterior cranial vault distraction osteogenesis to correct Chiari malformation type I associated with craniosynostosis

2021 ◽  
pp. 1-7
Keyword(s):  
Foramen Magnum ◽  
Posterior Cranial Fossa ◽  
Type I ◽  
Intracranial Volume ◽  
Tonsillar Herniation ◽  
Chiari Malformation Type I ◽  
Cerebellar Tonsillar Herniation ◽  
Cranial Fossa ◽  
The Mean ◽  
Tonsillar Descent

OBJECTIVE Posterior vault distraction osteogenesis (PVDO) is an effective tool to increase intracranial volume and expand the posterior cranial fossa. During PVDO, the authors extended osteotomy posterior to the foramen magnum to fully expand the posterior cranial fossa. The aim of this study was to investigate the efficacy of complete PVDO in posterior fossa expansion and treatment of Chiari malformation type I (CM-I) in patients with craniosynostosis. METHODS Patients with craniosynostosis who had undergone complete PVDO between January 2012 and May 2020 were reviewed retrospectively. A coronal osteotomy extending to the foramen magnum was performed and the foramen magnum was decompressed by removing its posterior rim with a 1-mm Kerrison rongeur. Four distractor devices were placed and the vector of distraction was controlled from the posterior to the inferior-posterior direction, depending on the deformity. Changes in the intracranial volume, posterior cranial fossa area, and cerebellar tonsillar descent were measured after complete PVDO by using CT and MRI. RESULTS A total of 11 patients with craniosynostosis and concurrent CM-I were included in the study. The mean age was 34.6 ± 24.0 months (continuous variables are expressed as the mean ± SD throughout). One patient had sleep apnea, which was consistent with CM-I, and another patient had a headache, which was nonspecific. The intracranial volume increased from 1179.6 ± 180.2 cm3 to 1440.6 ± 251.5 cm3 (p = 0.003; 24.5% increase compared to the preoperative volume). The posterior skull base area increased from 44.9 ± 19.3 cm2 to 72.7 ± 18.1 cm2 (p = 0.004). Cerebellar tonsillar descent decreased in all 11 patients after complete PVDO (preoperative: 10.8 ± 3.7 mm, postoperative: 2.7 ± 3.0 mm; p = 0.003). Among the 11 patients, 5 showed complete resolution of cerebellar tonsillar herniation. CONCLUSIONS Complete PVDO can more efficiently expand the posterior cranial fossa, unlike conventional methods. Moreover, it helps to relieve cerebellar tonsillar herniation. Complete PVDO is a powerful tool to increase the intracranial and posterior fossa volumes in patients with craniosynostosis and concurrent CM-I.

scholarly journals Anatomical basis of approaches to foramen magnum and lower clival meningiomas: comparison of retrosigmoid and transcondylar approaches

2003 ◽  
Vol 14 (6) ◽  
pp. 1-5 ◽  
Author(s):  
Agustinus Suhardja ◽  
Anne M. R. Agur ◽  
Michael D. Cusimano
Keyword(s):  
Anatomical Study ◽  
Foramen Magnum ◽  
The Other ◽  
Retrosigmoid Approach ◽  
Surface Areas ◽  
Anatomical Basis ◽  
Paired Student ◽  
The Mean ◽  
Lower Clivus ◽  
The Brain

Object Meningiomas of the lower clivus and foramen magnum are among the most challenging of all neurosurgical lesions. Debate continues regarding the most appropriate approach to this eloquent anatomical region. This anatomical study was undertaken to measure and compare the area of surgical exposures of the lower clivus achieved using the retrosigmoid and the extreme-lateral transcondylar (ELT) approaches. Methods Thirteen embalmed cadaveric heads were dissected bilaterally via the retrosigmoid approach on one side and the ELT approach on the other. The circumference of the area of exposure was delineated using beaded pins placed into the dura. After removal of the brain, the longest longitudinal and transverse axes of the pinned areas were measured and surface area calculated. The area of surgical exposure was also expressed as a percentage of the total area of the lower clivus. Normalized and adjusted surface areas were calculated using the bimastoid diameter. The areas of exposure were compared using the two-tailed paired Student t-test. The mean area of exposure required using the retrosigmoid approach was 19.8 ±14.7 mm2 (range 6–49 mm2) and that using the ELT approach was 27.8 ±22.8 mm2 (range 10–90 mm2). The mean percentage of the lower clivus exposed by the retrosigmoid approach was 14.9 ±3.6% (range 10–22%) and that exposed by the ELT approach was 20.5 ± 4.9% (range 10–25%). The ELT approach provided significantly greater area of operative exposure and allowed a significantly higher percentage of lower clivus and foramen magnum exposure than did the retrosigmoid approach (p <0.05). Normalized and adjusted surface areas, taking into consideration the bimastoid diameter, were also statistically significant in favor of the ELT approach. Conclusions The ELT approach provided a significantly greater area of exposure than did the retrosigmoid approach.

Surgical outcomes in adult patients with syringomyelia associated with Chiari malformation Type I: the relationship between scoliosis and neurological findings

2007 ◽  
Vol 6 (3) ◽  
pp. 216-221 ◽  
Author(s):  
Atsushi Ono ◽  
Futoshi Suetsuna ◽  
Kazumasa Ueyama ◽  
Toru Yokoyama ◽  
Shuichi Aburakawa ◽  
...  
Keyword(s):  
Chiari Malformation ◽  
Clinical Status ◽  
Japanese Orthopaedic Association ◽  
Foramen Magnum ◽  
Neurological Dysfunction ◽  
Type I ◽  
Chiari Malformation Type I ◽  
Group A ◽  
The Mean ◽  
Group B

Object The clinical characteristics of pediatric scoliosis associated with syringomyelia have been reported in previous studies, but scoliosis associated with syringomyelia in adults is rarely treated, and there is a paucity of detailed studies. In the present study of adult syringomyelia associated with Chiari malformation Type I, the authors investigated the relationships among the syrinx, scoliosis, and neurological data. Methods The population was composed of 27 patients (≥ 20 years of age) who underwent foramen magnum decompression for the treatment of syringomyelia. The patients were divided into two groups: those with scoliosis of 10° or more (Group A) and those without scoliosis (Group B). The authors assessed the length of the syrinx, duration of morbidity, and clinical status before and after surgery based on the Japanese Orthopaedic Association (JOA) Scale. There were 15 cases in Group A and 12 in Group B. The mean length of the syrinx was 12.8 vertebral bodies (VBs) in Group A and 7.2 VBs in Group B. The mean duration of morbidity was 14.2 years in Group A and 6.8 years in Group B. The mean preoperative JOA score was 10.1 in Group A and 14.4 in Group B, whereas the mean postoperative JOA scores were 11.9 and 15.8, respectively. There were significant differences between Groups A and B in length of the syrinx, duration of morbidity, and pre- and postoperative JOA scores. Conclusions In patients with syringomyelia and scoliosis the syringes spanned a greater number of VBs, the duration of morbidity was greater, neurological dysfunction was more severe, and surgical results were poorer. Scoliosis could be a predicting factor of the prognosis in patients with syringomyelia and Chiari malformation Type I.

scholarly journals Microcomputer-Based Quantification of Maize Streak Virus Symptoms in Zea mays

1998 ◽  
Vol 88 (5) ◽  
pp. 422-427 ◽  
Author(s):  
Darrin P. Martin ◽  
Edward P. Rybicki
Keyword(s):  
Zea Mays ◽  
Image Analysis ◽  
Maize Streak Virus ◽  
Computer Assisted ◽  
Streak Virus ◽  
Image Analysis System ◽  
Analysis Techniques ◽  
Computer Assisted Image ◽  
Analysis System ◽  
Image Analysis Techniques

We investigated the use of computer-assisted image analysis techniques for the objective quantification of maize streak virus (MSV) symptoms in Zea mays. We compared independent duplicate evaluations of chlorotic lesion areas occurring on MSV-infected leaves using visual assessment, a commercial image analysis system, and a custom image analysis system employing software developed in our laboratory. Relative to visual assessments of disease severity, computer-assisted image analysis employing both the commercial and custom systems provided significant enhancements in the accuracy and precision of chlorotic area estimations. The commercial image analysis system afforded no significant improvement in precision or accuracy over the custom system. An important advantage of examining images using the custom-written software was that the software permitted a high degree of analysis automation. Digitized images of maize leaves could be automatically analyzed by the custom software five times faster than, and with the same precision and accuracy as, when the same images were analyzed with the commercial software. Because of the flexibility of the image analysis techniques described, they should be applicable to the measurement of symptom severity in other plant host-pathogen combinations.

Studies on the Anatomical Structure of Fast-Growing Toona ciliate

2012 ◽  
Vol 472-475 ◽  
pp. 1963-1966
Author(s):  
Jin Sun ◽  
Xiao Bo Wang ◽  
Xiao Jing Wang ◽  
Yan Lin ◽  
Zhen Zhong Gao
Keyword(s):  
Growth Ring ◽  
Mean Value ◽  
Image Analysis System ◽  
Fast Growing ◽  
Coarse Texture ◽  
Vessel Elements ◽  
Toona Ciliata ◽  
The Mean ◽  
Analysis System ◽  
Tissue Proportion

In this paper, anatomical characters and tissue proportion of fast-growing Toona ciliata samples from Guangzhou was investigated assisted with the light microscope and image analysis system based on the principle of stereology. Qualitative and quantitative data were presented for purposes of identification. Results showed that fast growing T. ciliata was coarse texture with wide growth ring of 3~5cm.The ray proportion was 12.12%-25.56%, the mean value was 17.98%, increasing with time-dependent relevance. The vessel-elements proportion was 6.37%-10.00%, the mean value was 7.40%, increasing then declining and finally increasing. The fiber and other tissue proportion was 67.06%-79.92%, the mean value was 74.62%, declining by year.

Radiotherapy of the neck influences the distribution of laryngeal secretory glands

2005 ◽  
Vol 119 (12) ◽  
pp. 976-980 ◽  
Author(s):  
Tadashi Nakashima ◽  
Hideichiro Tomita ◽  
Sachio Tsuda ◽  
Shun-ichi Chitose
Keyword(s):  
Hypopharyngeal Cancer ◽  
Average Density ◽  
Image Analysis System ◽  
Average Ratio ◽  
Radiation Group ◽  
Glandular Cells ◽  
Secretory Glands ◽  
The Mean ◽  
Analysis System ◽  
The Voice

To elucidate the influence of radiation therapy on the larynx in patients who receive radiotherapy to the neck, we observed the changes in the distribution of the laryngeal glands. Human adult larynges from patients with either laryngeal or hypopharyngeal cancer were histopathologically examined, and the changes in the glandular distribution as well as in the ratio of serous or mucous type cells were surveyed using an image analysis system. The mean ratio of the area occupied by glandular acini in the subglottic larynx was 0.182 in the non-radiation group and 0.098 in the radiation group (p < 0.001). Although no statistical difference was observed, the average density of the glands decreased and the average ratio of serous-type/mucous-type glandular cells decreased in the irradiated larynx. The glandular acini are often replaced with fibrous connective tissue and the ratio of serous-type glandular cells decreases. These results indicate that not only the voice function but also the local defence function of the larynx might be impaired after radiotherapy.

scholarly journals MORPHOLOGICAL AND MORPHOMETRIC STUDY OF FORAMEN MAGNUM IN DRIED HUMAN SKULL BONES OF NORTH-WEST INDIAN REGION

2020 ◽  
Vol 8 (4.1) ◽  
pp. 7777-7781
Author(s):  
Suresh Sharma ◽  
◽  
Sakshi Mathur ◽  
Puneet Joshi ◽  
Upendra Kumar Gupta ◽  
...  
Keyword(s):  
West Indian ◽  
Craniovertebral Junction ◽  
Foramen Magnum ◽  
Morphometric Study ◽  
Transverse Diameter ◽  
North West ◽  
Important Landmark ◽  
Cranial Fossa ◽  
The Mean ◽  
Common Shape

Background: The Foramen Magnum is communication between vertebral canal and posterior cranial fossa and important landmark to key structures such as brain, spinal cord, vertebral arteries. Anatomical knowledge of the foramen magnum is significant for understanding the pathophysiology of various disorders of the craniovertebral junction as well as for planning surgical procedures. Materials and Methods: The study was conducted on 62 dry skulls of unknown gender obtained from the Department of Anatomy. The shape of foramen magnum was classified as oval, round, tetragonal, pentagonal, hexagonal and irregular in shape and measurements like anterio-posterior diameter and transverse diameter of foramen magnum were taken using the Digital Vernier sliding caliper. Results: In the present study most common shape was oval in 22 (35.48%) skulls, followed by Egg shape in 12 (19.35%) skulls and least common pentagonal shape in 1(1.61%) skulls. In our study the mean anteroposterior diameter was 34.17 mm. and mean transverse diameter was observed to be 28.86 mm. Conclusion: Results of our present study may help in neurosurgeons, orthopedicians, radiologist and anesthetist in North West indian population. KEY WORDS: foramen magnum, skull, transverse diameter, oval.

Effects of altered muscle activation on oxidative enzyme activity in rat alpha-motoneurons

1994 ◽  
Vol 77 (5) ◽  
pp. 2269-2274 ◽  
Author(s):  
K. Seburn ◽  
C. Coicou ◽  
P. Gardiner
Keyword(s):  
Muscle Activation ◽  
Voluntary Exercise ◽  
Medial Gastrocnemius ◽  
Oxidative Enzymes ◽  
Type I ◽  
Activity Levels ◽  
Image Analysis System ◽  
Muscle Disuse ◽  
The Central Nervous System ◽  
Analysis System

Some controversy exists as to whether alpha-motoneurons adapt their oxidative metabolism to changes in chronic activity levels and to altered status of their end organs, as occurs in other neuron types in the central nervous system. We measured, using a personal computer-based image analysis system, succinate dehydrogenase (SDH) activity in rat hindlimb motoneurons under conditions of increased activity (daily voluntary exercise plus treadmill endurance training, the latter 2 h/day, 4 days/wk, for 12 wk) and in a condition of muscle disuse (tetrodotoxin-induced paralysis for 2 wk) in which muscle oxidative enzymes are reduced. Although exercise-trained medial gastrocnemius showed significant adaptations (increased mean SDH activity of type I and increased proportion and total SDH activity of type I and combined I + IIa fibers), SDH activity of innervating motoneurons (identified by retrograde tracing using fast blue) was unchanged. In addition, tetrodotoxin-induced disuse, which results in hindlimb atrophy and SDH decreases (30% decrease measured in medial gastrocnemius muscle homogenates), failed to alter soma SDH or size in unspecified lumbar motoneurons. These results, obtained over a wider range of activity levels than in previous reports, suggest that the oxidative enzymes of motoneurons do not change despite clear adaptations in the muscles they innervate.

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