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PubMed2004

Fossa navicularis: anatomic variation at the skull base.

The fossa navicularis is a relatively rare anatomic variation of the skull base. Awareness of its existence will avoid misinterpretations of radiological images and unnecessary investigations. This study describes the appearance of the fossa navicularis, and investigates its incidence and whether it is related to pathology at the basiocciput. We studied 492 dry human skulls and 525 computer tomography (CT) images of patients. Dry skulls showing a fossa navicularis were investigated by CT scan, whereas patients identified as having a fossa navicularis were further examined with magnetic resonance imaging (MRI). To document the position of the fossa more precisely, measurements were made between the fossa navicularis and certain anatomic landmarks such as the foramen ovale, the pharyngeal tubercle, the posterior border of the vomer, the foramen lacerum, the carotid canal, and the occipital condyle. Upon examination, 26 of 492 skulls (5.3%) were found to have a fossa navicularis. Twelve were <2 mm in depth and the other 14 had a depth of >/=2 mm. Of the 525 patients, 16 (3.0%) were identified as having a fossa navicularis in CT images. Evaluation of MRIs showed no soft tissue lesions in any of these patients. Comprehensive anatomic details of the fossa navicularis have not been reported in the literature. The results of this study may be useful to radiologists, anatomists, and surgeons interested in the skull base.

Bone Cysts↗
PubMed1999

Three-dimensional computed tomography landmark measurement in craniofacial surgical planning: experimental validation in vitro.

PURPOSE: This study evaluated the measurement accuracy of three-dimensional (3D) volumetric images from spiral computed tomography (CT) in vitro. MATERIALS AND METHODS: The study sample consisted of nine cadaver heads that were submitted to an impact force by a special device to promote blunt traumatic craniofacial fractures. The heads were subsequently scanned by a spiral CT scanner (Toshiba Xpress S/X). The archived CT data were transferred to networked computer workstations (Sun Microsystems with Cemax VIP version 1.4 software) to generate 3D volumetric images. The visualization software was used to make interactive linear measurements on the 3D images. Measurements were made on the images twice by two observers, based on conventional craniofacial anatomic landmarks. The soft tissues were subsequently removed, and the same measurements were repeated on the cadaver heads with an electromagnetic digitizer (3 Space, Polhemus, Colchester, VT). RESULTS: The results showed no statistically significant differences between the 3D-CT and the physical measurements, with P>.05 for all measurements. The mean difference between the image and real measurements was less than 2 mm in all instances. CONCLUSIONS: It is concluded that measurement of the skull and facial bone landmarks by 3D reconstruction is quantitatively accurate for surgical planning and treatment evaluation of craniofacial fractures.

Aged↗
PubMedDate not supplied

The new imaging-based classification for describing the location of lymph nodes in the neck with particular regard to cervical lymph nodes in relation to cancer of the larynx.

For over five decades, the principle landmarks used in cervical nodal classification were clinical and defined either by palpation or found at the operative table. However during the past two decades, sectional imaging has consistently improved its quality and resolution and it has been shown that imaging can identify deep structures and adenopathy not amenable to palpation. Such disease can alter planned operative or radiation fields. In the April 1999 issue of the Archives of Otolaryngology-Head Neck Surgery, for the first time an imaging-based classification was published that gave precise anatomic landmarks for use in classifying metastatic cervical adenopathy. This classification was developed in consultation with head and neck surgeons so that the nodal levels classified by this imaging-based system would correspond closely with the nodal levels determined by utilizing the most commonly employed clinically-based classifications. This article describes this imaging-based classification and demonstrates its use with axial diagrams.

Head and Neck Neoplasms↗
PubMed1995

Posterior fontanelle cranial ultrasound: anatomic and sonographic correlation.

OBJECTIVE: The purpose of this study was to correlate normal brain anatomy as seen on posterior fontanelle cranial sonography with anatomical sections of the premature infant brain. MATERIALS AND METHODS: Images obtained from 93 cranial ultrasound examinations performed via both the anterior and posterior fontanelle in 53 infants, ranging in gestational age from 24 to 42 weeks, were reviewed to determine the ultrasound anatomy visible and also the changing appearances with increasing gestational age. The brains of five infants were sectioned at post-mortem according to predetermined anatomical landmarks to correlate with posterior fontanelle ultrasound scan planes. Brain preservation techniques involved fixation in formalin at room temperature, refrigeration of brain following formalin fixation, and brain freezing at -17 degrees C. RESULTS: In the premature infant brain, the subarachnoid space is up to 15 mm in thickness. Occipital lobe anatomy well seen includes occipital horns of lateral ventricles, and white matter tracts to the visual cortex and visual association areas. Brain anatomy was better appreciated on sections obtained following brain freezing rather than formalin fixation. CONCLUSION: Satisfactory ultrasound anatomic correlation of the premature brain is possible using a brain freezing preservation technique. Posterior fontanelle ultrasound allows detailed illustration of occipital lobe anatomy.

Brain↗
PubMed2006

Intrapartum translabial ultrasound (ITU): sonographic landmarks and correlation with successful vacuum extraction.

OBJECTIVE: Having studied intrapartum translabial ultrasound (ITU) to define easily obtainable sonographic criteria during maternal pushing, we used it dynamically immediately before vacuum extraction to determine its use in predicting successful operative vaginal delivery. METHODS: In a pilot study, maternal and fetal landmarks were determined sonographically during maternal pushing from a mid-sagittal translabial insonation using a curved array transducer in women delivering singleton fetuses in cephalic presentation spontaneously. With this transducer placed infrapubically ('infrapubic plane'), easily obtainable landmarks and signs were: (i) the 'infrapubic line', perpendicular to the long axis of the pubic joint and extending dorsally from its inferior margin in a mid-sagittal plane, (ii) the widest fetal head diameter and its movement with regard to the infrapubic line during pushing, and (iii) the 'head direction' with respect to the long axis of the symphysis. A three-dimensional reconstruction from a computed tomographic (CT) dataset of a normal female pelvis was then used to quantify accurately the spatial relationship between the infrapubic line and the anatomical landmarks. Finally, 20 pregnant women in spontaneous term labor with normal singleton fetuses in cephalic presentation and clinical indication for vacuum extraction were studied by ITU immediately before operative vaginal delivery. RESULTS: CT reconstruction demonstrated the infrapubic line to be 3 cm cranial to the parallel interspinous plane. Eleven of the 20 vacuum deliveries with the 'head-up' sign (head pointing ventrally) and objective descent of the fetal head below the infrapubic line, both noted at the height of pushing, resulted in successful ('simple' or 'moderately difficult') operative delivery. Lack of descent or lack of passage below the infrapubic line and horizontal or downward head direction were poor prognostic signs. CONCLUSIONS: ITU provides objective information on the dynamics of the second stage of labor, head station and head direction. ITU may be used to assess the prognosis for operative vaginal delivery.

Adolescent↗
PubMed2004

The expanded transposition flap: shifting paradigms based on experience gained from two decades of pediatric tissue expansion.

The authors present their experience with the design of expanded skin flaps gained over the past two decades in a large series of 995 expanded flap reconstructions performed in 626 operations in 430 patients. The indications for tissue expansion were giant congenital pigmented nevi (72.7 percent), scar contractures (11.2 percent), and a remainder for a variety of congenital and acquired deformities. Surgical strategies were reviewed retrospectively to determine the location in the body where the tissue expansion was performed, the number of procedures required to accomplish the reconstructive goal, and the design of the expanded flap that was used to reconstruct the involved area. Specific points that were noticed included contour deformities (such as webbing, dog-ears, or decreased limb circumference) following flap reconstruction, anatomic distortions (such as distortion of the eyebrow or the distance from the brow to hairline) following reconstruction, final position of the scars in relation to anatomic landmarks, borders of aesthetic units, and relaxed skin tension lines, and the potential for later scar contracture. Careful examination of reconstruction by region of involvement demonstrated significant advantages in the use of expanded transposition flaps over pure advancement. These advantages and the modifications in the design of expanded flaps for each body region are discussed in a series of representative cases. They emphasize the ability of transposition flaps to dissipate tension away from the flap apex and distribute it more proximally, thus redirecting the tension lines so there is less likelihood of anatomic distortion in the reconstructed area. Also, flaps designed in this manner allow improved contour by avoiding webbing, tenting across concavities, and bunching of skin laterally. The authors conclude that restricting the expanded flap design to advancement alone to minimize potential scarring severely limits the reconstructive capabilities of the added tissue and distracts from the surgeon's ability to accomplish the initial reconstructive goal. The cost of additional incisions is worthwhile to achieve better final contour of the reconstructed part, lesser risk of anatomic distortion, better position of the scars, and lowered risk of scar contracture.

Child↗
PubMed2006

MR imaging, MR spectroscopy, and diffusion tensor imaging of sequential studies in neonates with encephalopathy.

BACKGROUND: Although the imaging, spectroscopic, and diffusion characteristics of brains of infants with neonatal encephalopathy have been described, the time course during which these changes evolve is not clear. The results of sequential MR imaging studies--including anatomic MR imaging, proton MR spectroscopy, and diffusion tensor imaging (DTI)--of 10 patients enrolled prospectively in a study of neonatal encephalopathy are reported to help to clarify the time course of changes in different brain regions during the first 2 weeks of life. METHODS: Ten neonates were prospectively enrolled in a study of the evolution of MR findings in neonatal encephalopathy and were studied 2 (8 patients) or 3 (2 patients) times within the first 2 weeks of life. The MR examination included spin-echo T1 and T2-weighted images, DTI, and long echo time (288 milliseconds) proton MR spectroscopy. Diffusion parameters (diffusivity [D(av)], fractional anisotropy [FA], and individual eigenvalues) were calculated for 10 1-cm2 regions of interest in each hemisphere that were placed based on anatomic landmarks. D(av) and FA were then measured manually in the same areas on a workstation. Metabolite ratios (NAA/Ch, Cr/Ch, Cr/NAA, Lac/Ch, and Lac/NAA) were calculated in 7 regions of interest. Imaging appearance, diffusion parameters, and metabolite ratios were then evaluated longitudinally (comparing with other studies on the same patient at different times) and cross-sectionally (comparing all studies performed on the same postnatal day). RESULTS: In most of the patients a characteristic evolution of DTI and MR spectroscopy parameters was seen during the first 2 weeks after birth. Although the anatomic images were normal or nearly normal on the first 2 days after birth in most patients, abnormalities were detected on DTI (both visually and by quantitative interrogation of D(av) maps) and proton MR spectroscopy (abnormal metabolite ratios). These parameters tended to worsen until about day 5 and then normalize, though in several patients abnormal metabolite ratios persisted. Of interest, as areas of abnormal diffusivity pseudonormalized within one region of the brain they would develop in other areas. Therefore, the pattern of injury looked very different when imaging was performed at different times during this evolution. CONCLUSION: Patterns of injury detected by standard anatomic imaging sequences, DTI sequences, and proton MR spectroscopy varied considerably during the first 2 weeks after injury. The appearance of new areas of reduced diffusion simultaneous with the pseudonormalization of areas that had reduced diffusion at earlier times can result in an entirely different pattern of injury on diffusivity maps acquired at different time points. Awareness of these evolving patterns is essential if studies are performed and interpreted during this critical period of time.

Brain Diseases↗
PubMed1987

Preparation of large temporomandibular joint specimens for pathological study.

Ten fresh temporomandibular joint (TMJ) specimens about 5 X 4.5 X 3.5 cm in size were removed at autopsy by 5 cuts according to appropriate anatomical landmarks. After routine formalin fixation, the whole-TMJ specimens were wrapped with a thin layer of self-curing resin and then cut with a low speed bone saw along the parasagittal plane predetermined by x-ray guidance. Each specimen was serially cut into 4 to 5 parallel slices of 3 mm thickness, which were then decalcified with 14% EDTA and embedded in paraffin. Histological sections of 5 microns were stained with hematoxylin and eosin. The procedures were accomplished within 20 to 24 days after autopsy. With this technique, the anatomical interrelationships among the various joint components could be maintained and the macroscopic and microscopic topography of the TMJ could be studied in the desired reference plane. Therefore, the corresponding changes among the joint components in a diseased TMJ could be thoroughly examined. This technique was also applicable for the study of large specimens containing both hard and soft tissues.

Adolescent↗
PubMed1997

Ketamine in the field: the use of ketamine for induction of anaesthesia before intubation in injured patients in the field.

Intubating the subconscious, struggling patient in a pre-hospital setting can be a difficult task even in experienced hands. We performed a clinical prospective study to evaluate the applicability of ketamine for induction of anaesthesia before intubation in the field. Ketamine was distributed to all air medical rescue teams--trained reserve army volunteers from various medical specialties. Lectures and literature concerning the use of ketamine for anaesthesia induction before intubation were given. The physicians were instructed to administer ketamine, in a dose of 2 mg/kg intravenously, if a single intubation attempt failed. Following the administration of ketamine, a questionnaire was filled in by the physician. Analysis of the data was performed after 24 months. During the study period, intubation was indicated in 161 injured patients evacuated by air in Israel. In 29 patients (18 per cent) the first intubation attempt had failed and they were given ketamine. The reasons for failure of the first intubation attempt were restlessness or trismus in 23 patients and traumatic distortion of the upper airway anatomical landmarks in six. Following ketamine administration, intubation was successful in 19 patients (65.5 per cent) in all of whom the indication for ketamine administration was restlessness or trismus. All patients with upper airway anatomy distortion were given a cricothyroidotomy. There were no complications attributed to ketamine. All patients reached hospital alive. This preliminary study suggests that the use of ketamine in this pre-hospital setting is safe. The drug is effective in cases where the primary reason for failure to intubate is restlessness or trismus. The drug is not effective in cases of anatomical damage to the upper airway. In these cases, cricothyroidotomy should probably be performed as early as possible.

Adult↗
PubMed2006

Advanced virtual endoscopy for endoscopic transsphenoidal pituitary surgery.

OBJECTIVE: Virtual endoscopy (vE) is the navigation of a camera through a virtual anatomical space that is computationally reconstructed from radiological image data. Inside this three-dimensional space, arbitrary movements and adaptations of viewing parameters are possible. Thereby, vE can be used for noninvasive diagnostic purposes and for simulation of surgical tasks. This article describes the development of an advanced system of vE for endoscopic transsphenoidal pituitary surgery and its application to teaching, training, and in the routine clinical setting. METHODS: The vE system was applied to a series of 35 patients with pituitary pathology (32 adenomas, three Rathke's cleft cysts) operated endoscopically via the transsphenoidal route at the Department of Neurosurgery of the Medical University Vienna between 2004 and 2006. RESULTS: The virtual endoscopic images correlated well with the intraoperative view. For the transsphenoidal approach, vE improved intraoperative orientation by depicting anatomical landmarks and variations. For planning a safe and tailored opening of the sellar floor, transparent visualization of the pituitary adenoma and the normal gland in relation to the internal carotid arteries was useful. CONCLUSION: According to our experience, vE can be a valuable tool for endoscopic transsphenoidal pituitary surgery for training purposes and preoperative planning. For the novice, it can act as a simulator for endoscopic anatomy and for training surgical tasks. For the experienced pituitary surgeon, vE can depict the individual patient's anatomy, and may, therefore, improve intraoperative orientation. By prospectively visualizing unpredictable anatomical variations, vE may increase the safety of this surgical procedure.

Adult↗
PubMed1991

Overall body fat and regional fat distribution in young women: quantification with MR imaging.

Overall body fat and its distribution in different regions are important predispositions to known aberrations in lipid and glucose metabolism. The accuracy of MR imaging in estimating overall body fatness and regional fat distribution at individual landmarks was determined by comparing it with well-accepted measures by deuterium-oxide (D2O) dilution and bioimpedance analysis. Fourteen normal young women (athletes and control subjects) were studied. A total of 308 axial, T1-weighted, spin-echo MR images over a specific region in the trunk (21-24 scans per subject) were obtained. Morphometric computer image analysis was performed to determine the subcutaneous, internal, and total fat volumes in each image. The data were analyzed in two ways: data from all slices were summed to assess overall body fatness, and six anatomic landmarks were chosen for regional comparisons. MR-determined estimates of overall body fatness strongly correlated with total body fat measures by D2O dilution in both total fat (r = .91) and subcutaneous fat (r = .92) determinations. Athletes in both the low- and high-intensity training phases had significantly lower values of MR-determined total body fatness than did control subjects. Parallel to total body fatness, athletes had significantly lower MR-determined ratios of total fat/total volume in four of six individual landmarks compared with control subjects. Our experience suggests that MR is an accurate method to quantify overall body fatness, when compared with D2O dilution and bioimpedance analysis. MR could also discriminate regional components of subcutaneous and internal body fat at individual landmarks.

Adipose Tissue↗
PubMed2003

An approach to the three-dimensional display of left ventricular function and viability using MRI.

Cardiac MRI was performed in human volunteers to determine the magnitude of the misregistration (MSR) of cardiac landmarks due to variability in the diaphragm position for repeated breath-holds. Seven normal volunteers underwent MR imaging of the left ventricle (LV) to evaluate the magnitude of the endocardial centroid MSR. The MSR for a mid-ventricle short-axis image was 3.01 +/- 1.68 mm through-plane and 4.16 +/- 1.62 mm in-plane. A second order polynomial fit through the LV centroid coordinates minimized the in-plane component of the MSR error. Short-axis cine images, corrected for MSR, provided high-resolution 2D data from which an accurate anatomical model of the LV was generated. Anatomical landmarks were used to register parametric maps of myocardial perfusion and viability to the three-dimensional (3D) model, with the corresponding parameters displayed as color-encoded values on the endo- and epicardial surfaces of the LV. Registration of regional wall motion, perfusion and viability to the 3D model was performed for three patients with a history of cardiovascular disease. The proposed 3D reconstruction technique allows visualization in 3D of the LV anatomy, in combination with parametric mapping of its functional status.

Cardiomyopathies↗
PubMedDate not supplied

Image-guided resection of fibro-osseous lesions of the skull base.

BACKGROUND: Endoscopic resection of sinonasal fibro-osseous lesions remains a technical challenge because of the loss of anatomic landmarks and the frequent need to resect bone along the skull base. The purpose of this study was to evaluate the usefulness of image-guidance systems for the resection of these lesions. METHODS: Endoscopic surgery was performed in 10 patients with fibro-osseous lesions of the sinuses and skull base (six fibrous dysplasias and four osteomas). Indications for surgical intervention were recurrent infection (7), facial pain (3), mucocele (1), and compressive optic neuropathy (1). All surgeries were performed with an image-guidance system, which included an integrated high-speed drill system. RESULTS: Anatomic localization was accurate to within 1 mm when monitoring the depth of bone removal along the skull base. Complete resection of the fibro-osseous lesion was possible in six patients (60%) and partial removal was possible in four patients (40%). In the latter group, a margin of dysplastic bone was preserved along the ethmoid roof to prevent dural exposure. There were no intraoperative complications. Surgery resulted in resolution of infection and facial pain in nine patients (90%). Additional surgery was required in one patient (10%) who developed recurrent optic neuropathy because of continued dysplastic bone growth. Mean follow-up was 34 months (range, 13-67 months). CONCLUSION: Image-guidance technology appears to be ideally suited for the treatment of patients with fibro-osseous lesions of the sinonasal cavity. Real-time monitoring of the depth of bone removal relative to the skull base may enhance the safety and efficacy of such surgery.

Adult↗
PubMedDate not supplied

Anatomy of the posterior antebrachial cutaneous nerve: practical information for the surgeon operating on the lateral aspect of the elbow.

PURPOSE: To investigate the anatomic relationships of the posterior antebrachial cutaneous nerve (PABCN) to anatomic landmarks on the lateral side of the elbow. METHODS: The PABCN was explored in 30 cadaveric upper extremities. Distances were noted from easily identifiable structures including the lateral epicondyle, the lateral intermuscular septum, and the radial nerve. RESULTS: The path of the PABCN follows the spiral groove initially, diverging as the radial nerve pierces the lateral intermuscular septum. The PABCN emerges from the posterior compartment through a hiatus in the deep fascia at a mean of 6.6 cm proximal to the lateral epicondyle and passes a mean of 2.1 cm anterior to the lateral epicondyle. CONCLUSIONS: The anatomic relationships determined in this study should enable the surgeon to avoid injuring the PABCN when performing surgery in the lateral elbow region.

Aged↗
PubMed2004

Emergency gum elastic bougie-assisted tracheal intubation in four patients with upper airway distortion.

PURPOSE: The gum elastic bougie (GEB) has been in use for a long time and allows tracheal intubation in most cases of difficult direct laryngoscopy. Use of the GEB when anatomical landmarks of the upper airway are not recognizable has not been reported. We describe our experience of airway management with the GEB in cases of severe upper airway distortion. CLINICAL FEATURES: Four patients with severe respiratory distress caused by upper airway distortion secondary to various non-malignant causes were managed with the GEB. For these four patients, a rapid sequence induction of anesthesia was performed with a surgeon present during the procedure. The GEB was used as the initial intubating technique in all cases and allowed a rapid and successful tracheal intubation in spite of non-recognizable anatomical structures. The distal hold-up feeling after GEB insertion confirmed, in all cases, the correct intratracheal position of the GEB. CONCLUSION: The GEB can be a valuable tool in cases of difficult airway management caused by upper airway distortion. The lack of visualization of normal pharyngeal structures did not prevent the successful insertion of the GEB in the trachea in the four patients reported.

Adult↗
PubMed1988

Transrectal ultrasound versus cystography in the evaluation of anatomical stress urinary incontinence.

Thirty-two female patients with clinical and urodynamic findings of genuine stress urinary incontinence were evaluated before and 6 months after surgery for stress urinary incontinence. Twenty-nine control patients had identical evaluations before and 6 months after surgery which did not involve the urethrovesical junction. Twenty-four patients with primary bladder instability had similar evaluations and served as a second control group. Anatomical landmarks indicating support to the urethrovesical junction were evaluated by the position of the urethra at the most dependent point in the bladder on straining and the urethral descent on straining to beneath the posterior ramus of the symphysis pubis on bead chain cystography. The urethrovesical junction drop on straining was evaluated by transrectal ultrasonography. Cystographic and ultrasonographic tests for the position of the urethrovesical junction at the most dependent position in the bladder during straining were very sensitive in women with stress urinary incontinence (94 and 87% respectively) but much less specific (45 and 48% respectively). When evaluating anatomical support to the urethrovesical junction and its descent on straining, these tests were both highly sensitive (97 and 94% respectively) and specific (76 and 96% respectively) in women with genuine stress urinary incontinence. Simple clinical tests for support of the urethrovesical junction, such as the Q tip test, are non-specific in patients with stress urinary incontinence. Transrectal ultrasonography is a simple and quick out-patient procedure. The availability of ultrasound equipment in most clinics and the high sensitivity and specificity of the test make it an attractive and cost-effective alternative to X-ray cystography in the pre-operative evaluation of anatomical support to the urethrovesical junction.

Adult↗
PubMed1984

Surgeon's view of the skull base from the lateral approach.

This paper presents the surgical anatomy of the skull base and infratemporal fossa. The information has been derived from the author's own experience in surgical and cadaver dissection, standard anatomical references, and selected experience of other skull base surgeons. Because the lateral approach has become the utilitarian method of exposure, the intricate detailed anatomy is demonstrated from this view at five levels of dissection, so the surgeon may gain a practical understanding of the surgical relationship of critical structures. Consistent anatomical landmarks can be used by the surgeon in the location of these critical structures. The styloid process, sphenoidal spine, and middle meningeal artery identify the internal carotid artery as it enters the carotid canal. The bony or fibrous septum that divides the jugular foramen into neural and vascular compartments may be used to better identify nerves IX, X, and XI. The zygomatic root is useful for location of the middle fossa dura. The lateral pterygoid plate leads directly to the foramen ovale. The increased precision of dissection permitted by use of the microscope requires an increased level of knowledge of anatomical structures in this area. It is hoped that the information presented in this paper will assist surgeons in the meticulous and thorough removal of skull base tumors and in the preservation of neural and vascular structures that are presently being sacrificed.

Anthropometry↗
PubMed1995

Three-dimensional reconstruction of the rubrocerebellar premotor network of the turtle.

Neuroanatomical studies have demonstrated that the organization of the reptilian rubrocerebellar limb premotor network is similar to that of mammals. This network is composed of prominent recurrent connections among the red nucleus, lateral cerebellar nucleus and lateral reticular nucleus. In this paper the rubrocerebellar system of the turtle was three-dimensionally reconstructed to permit detailed examination of its anatomical organization. Each nucleus and its major efferent pathway was imaged and reconstructed from separate anatomical cases. Section images were used to draw tissue boundaries, mark cell positions and locate axonal trajectories. For each nucleus, drawings of section images containing labeled cells were stacked in the rostrocaudal direction using anatomical landmarks, and a graphic model of the surface was constructed using the method of triangulation. An ellipsoid of equal concentration was computed for each nucleus to ascertain their three-dimensional boundaries and location within the brainstem. To examine the entire rubrocerebellar network, a template of the turtle brainstem and cerebellum was constructed. The component nuclei of the rubrocerebellar network and their axonal projections were then spatially warped onto the template reconstruction on a section by section basis. The final three-dimensional reconstruction of the turtle rubrocerebellar limb premotor network could be rotated in space, allowing proper visualization of the anatomical details of this system. Furthermore, we were able to mathematically section through the reconstruction to obtain brainstem slices with differing orientations and thickness.

Animals↗