A new troodontid (Dinosauria, Theropoda) braincase from the Dinosaur Park Formation (Campanian) of Alberta

1993 ◽  
Vol 30 (10) ◽  
pp. 2231-2247 ◽  
Author(s):  
Philip J. Currie ◽  
Xi-Jin Zhao

A new, well-preserved specimen of Troodon formosus is the first to reveal the internal anatomy of the lower part of the braincase. In addition to providing new information on the brain of this highly encephalized dinosaur, the uncrushed bones clear up anatomical details left obscure by earlier studies. Computerized tomography (CT) scans reveal the nature of the inner ear and the course of the pneumatic ducts diverging from the middle ear. Evidence is presented to show that four of the five periotic pneumatic systems found in bird skulls are present in Troodon. The anterior tympanic recess is the most elaborate system, and diverticula from each side extend anteriorly, dorsally and, posteriorly from the middle ear. The posterior tympanic recess is located within the paroccipital process and the basioccipital, but the pneumatopore posterolateral to the stapedial recess is secondarily closed. The dorsal periotic sinus is represented by a smooth-surfaced concavity on the lateral surface of the prootic. The position of a pneumatic recess in this region is demonstrated by the presence of a pneumatopore in the quadrate. Diverticula from the anterior and posterior tympanic recesses are connected within braincase bones, and a possible pneumatopore in the prootic may connect these to the dorsal tympanic recess. The pneumatic condition of the troodontid articular is unknown. Contralateral connections of the sinus systems have been used to argue for a close relationship between birds and crocodiles, but their presence in this specimen suggests that they appeared more than once in archosaurs or that they are plesiomorphic for crocodiles, dinosaurs, and birds. Cranial pneumaticity cannot be used by itself to resolve the interrelationships of crocodiles, theropods, and birds, but other characters suggest derivation of birds from theropods.

1981 ◽  
Vol 89 (5) ◽  
pp. 861-866 ◽  
Author(s):  
William N. Hanafee

Computerized tomographic (CT) scanning for intracanalicular tumors requires air as a contrast agent within the internal auditory canal and special computer manipulations of the image to visualize small tumors. The same computer manipulations of CT scans provide detail of the middle and inner ear structures not available by non-CT tomographic techniques. The demonstration of horizontal semicircular canal fistula is one area in which CT scanning is clearly superior. Some pitfalls of the technique and interpretation of it will be discussed.


Ameghiniana ◽  
2019 ◽  
Vol 57 (1) ◽  
pp. 58 ◽  
Author(s):  
Ariana Paulina-Carabajal ◽  
Mauro Nicolas Nieto
Keyword(s):  
Ct Scans ◽  

1996 ◽  
Vol 33 (6) ◽  
pp. 524-529 ◽  
Author(s):  
Linda D. Vallino-Napoli

Objective To examine the prevalence and type of hearing loss and otopathology in patients with Pfeiffer syndrome. Design Retrospective and prospective study design. Setting A pediatric tertiary care hospital. Subjects Nine patients-ranging in age from 2 to 12 years. Method Hearing levels and middle ear function were assessed using standard procedures. Otoscopy was also conducted. Computerized tomography (CT) scans of the temporal bone were obtained to study outer, middle, and inner ear anatomy. Results Hearing loss was present in eight of the nine patients. The degree of loss varied but was moderate to severe in most patients. Seven patients had conductive hearing loss and one had mixed loss; none had purely sensorineural loss. Four patients had a history of middle ear effusion. Primary CT findings showed stenosis and/or atresia of the external auditory canal, hypoplasia of the middle ear cavity, and an enlarged middle ear cavity. The ossicles were hypoplastic in a few cases. With one exception, inner ear anatomy was normal. Conclusion Otologic malformations and hearing loss are features of Pfeiffer syndrome. Major factors contributing to hearing loss were anatomic abnormalities of the external auditory canal and middle ear, which can be identified by computerized tomography. Otitis media was also present and may have caused or contributed to the hearing loss. We recommend that the computerized tomographic study, which is often used to evaluate and plan treatment for the craniofacial skeleton, be extended to include a thorough evaluation of otologic structures In patients with Pfeiffer syndrome.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5456 ◽  
Author(s):  
M. Belen von Baczko ◽  
Jeremías R.A. Taborda ◽  
Julia Brenda Desojo

The paleoneuroanatomy of pseudosuchian archosaurs is poorly known, based on direct examination of the internal morphology of braincases and a few artificial endocasts. Among aetosaurs, only one endocast has been described almost a century ago by Case (1921) corresponding to Desmatosuchus spurensis from the Chinle Formation (Norian) of Texas, US, based on a resin cast. Here, we describe the first natural endocast of an aetosaur, Neoaetosauroides engaeus from the Los Colorados Formation (Norian) of NW Argentina, and also developed the first digital endocast of this taxon including the encephalon, cranial nerves, inner ear, and middle ear sinuses. The neuroanatomy of Neoaetosauroides engaeus exhibits several differences from that of Desmatosuchus spurensis despite their phylogenetic proximity, which may be a reflection of their different habits. The information provided by the endocasts of Neoaetosauroides engaeus about its olfactory region and the orientation of its head, based on the inclination of the inner ear, could support the proposal for an animalivorous diet, instead of an herbivorous one as in most aetosaurs. The new information here obtained contributes to the knowledge of the neuroanatomical diversity of archosauriforms and more specifically among pseudosuchians and their paleobiological roles in the Triassic continental communities.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
C. A. Neves ◽  
E. D. Tran ◽  
I. M. Kessler ◽  
N. H. Blevins

AbstractMiddle- and inner-ear surgery is a vital treatment option in hearing loss, infections, and tumors of the lateral skull base. Segmentation of otologic structures from computed tomography (CT) has many potential applications for improving surgical planning but can be an arduous and time-consuming task. We propose an end-to-end solution for the automated segmentation of temporal bone CT using convolutional neural networks (CNN). Using 150 manually segmented CT scans, a comparison of 3 CNN models (AH-Net, U-Net, ResNet) was conducted to compare Dice coefficient, Hausdorff distance, and speed of segmentation of the inner ear, ossicles, facial nerve and sigmoid sinus. Using AH-Net, the Dice coefficient was 0.91 for the inner ear; 0.85 for the ossicles; 0.75 for the facial nerve; and 0.86 for the sigmoid sinus. The average Hausdorff distance was 0.25, 0.21, 0.24 and 0.45 mm, respectively. Blinded experts assessed the accuracy of both techniques, and there was no statistical difference between the ratings for the two methods (p = 0.93). Objective and subjective assessment confirm good correlation between automated segmentation of otologic structures and manual segmentation performed by a specialist. This end-to-end automated segmentation pipeline can help to advance the systematic application of augmented reality, simulation, and automation in otologic procedures.


1990 ◽  
Vol 72 (6) ◽  
pp. 975-979 ◽  
Author(s):  
J. Alexander Marchosky ◽  
Christopher J. Moran ◽  
Neal E. Fearnot ◽  
Charles F. Babbs

✓ For the treatment of malignant gliomas, a technique for implanting hyperthermia catheters was developed that utilized a stereotactic template and head-stabilization frame mounted on a computerized tomography (CT) scanner. Computerized tomography scans were used to measure tumor dimensions and to determine the number, implantation depths, and active heating lengths of the catheters, which were implanted through twist-drill holes while the patient was in the CT room. Heat was subsequently delivered via implanted catheters using a computer-controlled hyperthermia system, which partially compensates for heterogeneous and time-varying tumor blood flow.


1993 ◽  
Vol 4 (3) ◽  
pp. 227-237 ◽  
Author(s):  
Donald G. Stein ◽  
Marylou M. Glasier ◽  
Stuart W. Hoffman

It is only within the last ten years that research on treatment for central nervous system (CNS) recovery after injury has become more focused on the complexities involved in promoting recovery from brain injury when the CNS is viewed as an integrated and dynamic system. There have been major advances in research in recovery over the last decade, including new information on the mechanics and genetics of metabolism and chemical activity, the definition of excitotoxic effects and the discovery that the brain itself secretes complex proteins, peptides and hormones which are capable of directly stimulating the repair of damaged neurons or blocking some of the degenerative processes caused by the injury cascade. Many of these agents, plus other nontoxic naturally occurring substances, are being tested as treatment for brain injury. Further work is needed to determine appropriate combinations of treatments and optimum times of administration with respect to the time course of the CNS disorder. In order to understand the mechanisms that mediate traumatic brain injury and repair, there must be a merging of findings from neurochemical studies with data from intensive behavioral testing.


1999 ◽  
Vol 120 (5) ◽  
pp. 643-648 ◽  
Author(s):  
Michael E. Hoffer ◽  
Ben J. Balough ◽  
Richard D. Kopke ◽  
Jenifer Henderson ◽  
Michael Decicco ◽  
...  

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