Canal Height Research Articles

Evaluation of thoracic vertebrae in healthy White New Zealand rabbit (Oryctolagus Cuniculus): Computed tomographic and morphometric study.

BackgroundComputed tomography currently has a prominent role in diagnosis and evaluation of vertebral column. On the other hand, a thorough knowledge about vertebral column property in normal state is prerequisite an accurate diagnosis of different abnormalities in this region.ObjectiveThe purpose of this study was to present a complete and exact descriptive and morphometric evaluation of thoracic vertebrae in rabbits with computed tomography. In images which were constructed by CT, several structures and different parts of the thoracic vertebrae have been named.MethodsTen healthy, mature, White New Zealand rabbits were evaluated. The morphologic and morphometric parameters of the thoracic vertebrae were studied. In this study, several parameters of thoracic vertebrae, such as vertebral body height, spinous process height, transverse process length, transverse process width, etc., were measured by computed tomography.ResultsSome parameters, such as spinal canal height, spinal canal width, pedicle length, pedicle width, end plate width, and endplate height, had no significant difference through thoracic vertebrae but other parameters, such as vertebral body height, transverse process length, transverse process width, spinous process angle, transverse process angle, and vertebral body length, had a significant difference.ConclusionsIn this study, a comprehensive anatomic atlas of CT anatomy of the thoracic vertebrae was produced for use by veterinary radiologists, clinicians, and surgeons. Finally, we must mention these two important points: (1) Many of the differences observed between rabbits and humans are based on the way the trunks of these two creatures are located on the ground and the differences in the way their bodies move. (2) In studies that are done by modelling humans on animals, it should be noted that the terms used in animal anatomy are different and the names are used using the principles of veterinary anatomy.

The Effect of Inlet Notch Variations on Turbine Speed in Pico-hydro Power Plants

Energy is an important element in the continuity of human activities. Indonesia has the potential to produce 94.3GigaWatt of electricity in the hydropower sector, but only a few can be utilized, which is only 4.2GigaWatt [1]. This study aims to utilize renewable energy that has not been utilized optimally, especially in Indonesia. This study exploits the potential of water flow from the Coban Wonoasri River, Bangun Village, Munjungan District, Trenggalek Regency which has a low head but has a fairly heavy discharge. The basin cone for making vortex flow has a canal length of 1450mm, a canal width of 231.5mm, and a canal height of 500mm with a basin cone diameter of 560mm, a basin cone height of 700mm, and a water outlet diameter of 90mm. A vortex turbine with a diameter of 270mm and a height of 210mm with a total of 8 blades, a blade curvature of 30°, and a blade tilt of 22.5° was used for research on this low head river. The inlet notch variations that will be used are angles of 0°, 17.82°, 19.30°, and 19.98°. The inlet notch with a width of 0° and a discharge of 8.81l/s cannot produce turbine rotation because the vortex flow is not formed properly. Inlet notch with a width of 17.82° and 19.30° produces an average turbine speed of 157.2 rpm and 159.2 rpm. The variation of the inlet notch with a width of 19.98° produces the best turbine speed of 162.7 rpm with a flowrate of 7.72l/s.

Polypropylene mesh inhibits post-laminectomy compressive scar formation in rabbits: Histopathological and computational morphometric evaluation

We evaluated the effect of polypropylene mesh placement on post-laminectomy compressive scar formation in rabbits. Twenty-two white male New Zealand rabbits were distributed into two groups (n = 11). In the control group, the animals underwent lumbosacral laminectomy, whereas in the mesh group, the rabbits were submitted to lumbosacral laminectomy followed by the attachment of a polypropylene mesh to the vertebrae by the application of N-butyl cyanoacrylate. After eight weeks, the rabbits were euthanized, and the laminectomy area was collected for macro- and microscopic analyses. Macroscopically, we evaluated the (1) vertebral canal height; (2) laminectomy width and (3) length; and (4) fibrosis width, (5) height, and (6) length. Microscopically, we evaluated (7) fibroblasts; (8) the thickness of the dura-mater; and (9) the distance between the dura-mater and the laminectomy area. Macroscopically, there were no differences between the groups regarding vertebral canal height; width and length of the laminectomy; and fibrosis width. However, the height, and length of fibrosis were smaller in the mesh group. Microscopically, there were no differences in dura mater thickness and the distance between the dura mater and laminectomy area, but fewer fibroblasts were observed in the mesh group. This indicated that the polypropylene mesh improved tissue repair, with greater tissue organization. The results demonstrate that the use of a polypropylene mesh in the treatment of post-laminectomy wounds in rabbits reduces the severity of compressive fibrous scar formation. Polypropylene mesh is presented as a good alternative to reduce complications associated with laminectomy surgeries.

Three-Dimensional Analysis of the Nasopalatine Canal in Dentulous and Edentulous Maxilla – A Cone-Beam Computed Tomography Study

Introduction: Dental esthetics has become an important concern today, and the patients consider the esthetic outcome to be an important factor in the anterior maxilla. Nasopalatine canal (NPC) plays an important role in making decisions regarding implant placement in the anterior maxilla. The aims of the present study were to analyze and compare the length and diameter of NPC and bone dimensions anterior to the canal in dentulous and edentulous maxilla for dental implant consideration using cone-beam computed tomography (CBCT). Materials and Methods: Sixty CBCT scans were collected retrospectively for the examination of NPC of individuals who had undergone CBCT scans for dental treatment purposes. The length of the canal and bone dimensions anterior to the canal were measured in multiplanar reformation. Results: The mean canal length was less in edentulous than dentulous patients. Moreover, the bone width anterior to the canal and bone height were also more in dentulous patients, with mean bone width being 8.518 ± 1.9 mm and bone height 7.993 ± 1.4 mm. The bone width and bone height in edentulous cases were 6.910 ± 1.44 mm and 5.183 ± 1.1 mm, respectively. Conclusion: Although there are variations in each patient, thorough knowledge of NPC and bone dimension is essential for implant placement to avoid any complication.

Dynamic MRI is reliable for evaluation of the lumbosacral spine in healthy dogs.

Magnetic resonance imaging (MRI) is commonly used to diagnose degenerative lumbosacral stenosis; however, studies show limited correlation between imaging and clinical signs. The purpose of this prospective observer agreement study was to use dynamic MRI of the lumbosacral (LS) spine of healthy dogs to determine reliable reference ranges. Twenty-two healthy large breed dogs were prospectively enrolled. MRI of the LS spine was performed in T2-weighted, T1-weighted, and T2-weighted SPACE sequences in neutral, flexed, and extended positions. Four observers performed image analyses. Measurements included LS angle, vertebral canal height and area, and LS foraminal areas. Ordinal categorical assessment of loss of fat signal in the foramina, LS compression, intervertebral disc (IVD) degeneration, spondylosis, and IVD protrusion was also performed. The majority of values were significantly larger in flexion versus neutral position, and significantly smaller in extension versus neutral position (P<.05). Subclinical compression and IVD protrusion was noted in a neutral position in 45% and 55% of dogs and in an extended position in 85% and 73% of dogs, respectively. Interobserver agreement was strong (intracluster correlation coefficient [ICC]>.5) except for the L7:LS vertebral canal area ratio (ICC ≤ .03). Intraobserver agreement was high (rho>.5) for all measurements except for the mid-L6:LS vertebral canal height ratio (rho=.38). There was poor interobserver agreement for loss of fat signal in the foramina and evidence of compression. This study provides the groundwork for future studies using dynamic MRI to evaluate dogs with signs of clinical LS disease.

Thoracic vertebral canal stenosis in cats: clinical features, diagnostic imaging findings, treatment and outcome.

The aim of this study was to describe the clinical features, diagnostic imaging findings, treatment and outcome in cats with thoracic vertebral canal stenosis (TVCS). Medical records and imaging studies of cats with TVCS were retrospectively reviewed. Outcome was acquired from patient records and from owners or referring veterinary surgeons via a telephone questionnaire. For each case, breed-, age- and sex-matched controls were identified with CT imaging of the thoracic vertebral column. For each cat, vertebral canal height was determined at three levels for each thoracic vertebra. Vertebral canal heights were compared between control cats of different breeds and between affected and control cats of the same breed. Nine TVCS cases were included. British Shorthairs and male neutered cats were over-represented (P <0.05). Median age at presentation was 9 years. All cats were presented for a chronic, progressive, painful, ambulatory, T3-L3 myelopathy. Five cats were treated conservatively, three surgically and one was euthanased. Two cats treated surgically demonstrated improvement of clinical signs and one demonstrated initial improvement followed by deterioration. Of the conservatively treated cats, three deteriorated and two improved. Compared with controls, affected cats had a lower vertebral canal height at multiple thoracic vertebral levels, being most prominent for British Shorthairs and domestic shorthairs (P <0.05). Unaffected British Shorthairs had a lower thoracic vertebral canal height at multiple levels than control domestic shorthairs (P <0.05). TVCS should be considered a differential diagnosis in middle-aged to older cats presenting with a chronic, progressive, painful, T3-L3 myelopathy. The predisposition of British Shorthairs could be explained by a narrower vertebral canal in this breed.

Definition of ideal configuration for femoral neck screw fixation in older people

Femoral neck fractures are the most common injuries encountered by older individuals, and they are associated with high mortality and morbidity. Internal fixation to femoral neck fracture with cannulated screws placed with a configuration of an inverted triangle remain a feasible and effective treatment for femoral neck fractures. The objection of this research was to evaluate the femoral neck morphology, especially the shape of the femoral neck in Chinese people to find the optimal screw position and interval between the screws. 96 consecutive normal subjects without any previous proximal femur operation were reviewed. The patients’ information were collected from our database. The minimum of neck canal height (NCHM), neck canal width (NCWM) and inclination angle (AIA and PIA) were measured in different level. There was a significant difference between the AIA and PIA, neck canal height at inferior and superior 1/3 on posterior wall (NCHIP and NCHSP). Although there was a significant difference between the neck canal height at inferior and superior 1/3 on anterior wall (NCHIA and NCHSA, p < 0.001), but the changes were small. The shape of the anterior wall was perpendicular to the horizon and almost parallel with the FNA. In contrast, the shape of the posterior wall resembled a reverse question mark. The inverse triangular fixation was in accordance with the morphology of the femoral neck, and triangular fixation had a high risk of perforation, which may lead to nonunion and avascular necrosis. The anterior screw can be inserted easily with the help of a C-ARM, and the posterior screw positioned mildly posterior to the femoral shaft axis is recommended.

Comparing Radiographic Parameters for Single-Level L5-S1 Interbody Fusion: Anterior Lumbar (ALIF) Versus Transforaminal Lumbar Interbody Fusion (TLIF)

Abstract INTRODUCTION The lumbosacral junction acts as a transition point between the mobile lumbar spine and the rigid pelvis. It is thereby susceptible to degenerative changes necessitating fusion at L5-S1. In this study, we compared radiographic outcomes observed from single-level anterior lumbar interbody fusion (ALIF) and transforaminal lumbar interbody fusion (TLIF) at this level. METHODS Retrospective review of single-level ALIF and TLIF with up to one level PSF at L5-S1 between May 2007 and October 2018 was undertaken. X-ray measurements were gathered for lumbar lordosis, segmental lordosis, pelvic tilt, sacral slope, pelvic incidence, pelvic incidence-lumbar lordosis mismatch, anterior/posterior disc height, and sagittal vertical axis. Computed tomography /magnetic resonance imaging was used to determine central canal area, sagittal diameter, foraminal height, and foraminal area. RESULTS A total of 47 ALIF patients and 50 TLIF patients were included. Patients averaged 53.7 ± 10.1 yr of age for ALIF and 49.4 ± 14.7 yr old for TLIF (P = .094) with significant differences (P = .0017) seen with gender as ALIF had 60.4% males and TLIF 70.0% females. Single-level ALIF led to significantly (P = .0010) more segmental lordosis (+5.75° ± 7.31°) than TLIF (+0.25° ± 6.55°), though differences in lumbar lordosis were not statistically significant (P = .52). ALIF significantly increased both anterior (+10.4 ± 4.32 mm vs +4.30 ± 3.55 mm; P &lt; .0001) and posterior disc height (+4.33 ± 3.32 mm vs + 2.98 ± 2.07 mm; P = .043) than TLIF. Changes in sagittal vertical axis also significantly differed (P = .030) with ALIF decreasing sagittal vertical axis by 17.8 ± 26.4 mm from +60.3 mm to + 42.5 mm, and TLIF increasing by 0.95 ± 25.8 mm from 39.9 mm to 40.9 mm. Pelvic tilt, sacral slope, pelvic incidence, pelvic incidence-lumbar lordosis mismatch had no significant differences. No statistically significant differences were observed with central canal area, sagittal diameter, foraminal height or foraminal area between ALIF and TLIF. CONCLUSION At L5-S1, the ALIF approach leads to increased segmental lordosis, disc height, while also decreasing sagittal vertical axis to a significant degree than TLIF. However, these two approaches were no different with regards to pelvic parameters and measures of central canal and foraminal decompression.

Variations in the Size and Shape of Human Cochlear Malformation Types.

ABSTRACTThe objective of this study is to determine the variations in size and shape of the most widely recognized cochlear malformation types using three‐dimensional (3D) visualization. Using 3D slicer freeware, the complete inner‐ear structures were segmented from 46 anonymized high‐resolution computed tomography (HRCT) image datasets. Cochlear height, internal auditory canal height, and width were measured from the axial plane. Cochlear basal turn diameter was measured from the oblique coronal plane. Number of cochlear turns was measured from the 3D images and the corresponding cochlear duct length (CDL) was estimated using the CDL equations given in Alexiades et al. [Otol Neurotol 36 (2015) 904–907]. Out of 46 preoperative HRCT image datasets of human temporal bone, cochlear anatomy types including normal anatomy (4), enlarged vestibular aqueduct syndrome (3), cochlear aplasia (2), incomplete partition Types I (8), II (Mondini's deformity) (3), and III (X‐linked) (4), cochlear hypoplasia (CH) (17), and common cavity (CC) (5) were identified. Majority of CH cases had cochlear height shorter than 4 mm whereas the CC cases measured cochlear height above 6 mm. For all the other malformation types, cochlear height was between 4 and 6 mm. In terms of “A” value, majority of CH cases showed shorter “A” value of <7.5 mm, which is in the lower end in comparison to the rest of the malformation types reported in this study. 3D‐visualization shows the size and shape variations of all the structures of inner ear and also improves the clinicians' ability to visualize cochlear anatomy and nearby structures much easier than from the 2D image slices. Anat Rec, 302:1792–1799, 2019. © 2019 The Author. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association for Anatomy

Biometrical sexual differentiation of fourth, fifth and sixth lumbar vertebrae in blue bull (Boselaphus tragocamelus)

The present study was carried out on the lumbar vertebrae of adult Blue bull (Boselaphus tragocamelus) of either sex. Biometrical observations on different parameters of lumbar vertebrae reflected significance (P Less than 0.05) differences between the sexes of this species. It was confirmed that the average length of body gradually decreased from fourth to sixth lumbar vertebrae in the Blue bull. The average transverse diameter or width of vertebral canal and average vertical diameter or height of the vertebral canal was largest in the sixth lumbar vertebra. The average length of transverse process gradually increased from fourth to fifth lumbar vertebra and then it suddenly decreased in the sixth lumbar vertebra. The average height of the dorsal supraspinous process gradually decreased from fourth to sixth lumbar vertebrae and it was lowest in the sixth one. The data on the biometry of fourth, fifth and sixth lumbar vertebrae of Blue bull would develop a baseline that could be useful to the wild life Veterinarians in identification and solving vetero-legal cases.

Evaluation of osseous‐associated cervical spondylomyelopathy in dogs using kinematic magnetic resonance imaging

Osseous-associated cervical spondylomyelopathy in dogs is characterized by both static and dynamic spinal cord compression; however, standard MRI methods only assess static compression. In humans with cervical spondylotic myelopathy, kinematic MRI is commonly used to diagnose dynamic spinal cord compressions. The purpose of this prospective, analytical study was to evaluate kinematic MRI as a method for characterizing the dynamic component of osseous-associated cervical spondylomyelopathy in dogs. We hypothesized that kinematic MRI would allow visualization of spinal cord compressions that were not identified with standard imaging. Twelve client-owned dogs with osseous-associated cervical spondylomyelopathy were enrolled. After standard MRI confirmed a diagnosis of osseous-associated cervical spondylomyelopathy, a positioning device was used to perform additional MRI sequences with the cervical vertebral column flexed and extended. Morphologic and morphometric (spinal cord height, intervertebral disc width, spinal cord width, vertebral canal height, and spinal cord area) assessments were recorded for images acquired with neutral, flexion, and extension imaging. A total of 25 compressions were seen with neutral positioning, while extension identified 32 compressions. There was a significant association between extension positioning and presence of a compressive lesion at C4-C5 (p = 0.02). Extension was also associated with a change in the most severe site of compression in four out of 12 (33%) dogs. None of the patients deteriorated neurologically after kinematic imaging. We concluded that kinematic MRI is a feasible method for evaluating dogs with osseous-associated cervical spondylomyelopathy, and can reveal new compressions not seen with neutral positioning.

Insight of Dogs' Inner Mandible Anatomy using Mathematical Models.

This study was performed in a sample of 20 dogs (n=20) and aimed to: (1) characterize the mandible height (Mh), mandibular canal height (MCh) and distance between the inter-dental alveolar margin and the mandibular canal (dIAM-MC) dimensions, and (2) to develop mathematical models that express the insight's mandible anatomy of those important mandible structural elements allowing the prediction of their dimensions using physical parameters such as patient body weight (Wg) and the canine tooth width at the free gingival margin level-(wCGM). Lateral-view X-rays of both sides of the skull were taken for all the individuals. Three mathematical prediction models were developed to calculate Mh, MCh and dIAM-MC. Achieved proportions of the mandible considered parameters regarding its height were of 36.45% for MCh, 50.90% for dMAI-MC and 12.65% for vMC. Statistically significant differences were registered between the Wg and wCGM (P=0.00), Mh (P=0.00), MCh (P=0.00) and dIAM-MC (P=0.00). Only the Wg presented a strong correlation with the wCGM (R=0.58), Mh (R=0.70), dIAM-MC (R=0.60) and MCh (R=0.68). These models will allow a clinician to estimate the size of the mandible structures by only using data obtained during the physiological examination, with a sufficiently high prediction capacity and a very low standard error. The study points out the relationships of physiological parameters such as Wg and wCGM with mandible anatomical structural elements considered as important in oral surgery. The results of this study give the surgeon a new additional tool providing more information on the mandible anatomical structures and its relationships. This reduces the risk of iatrogenic lesions during the oral surgical procedures and improves patient safety.

Radiographic study of the distribution of maxillary intraosseous vascular canal in Koreans.

BackgroundThis study aimed to investigate the distribution and prevalence of intraosseous loop (anastomosis between posterior superior alveolar artery and infraorbital artery) in Koreans detected on computed tomography (CT) images taken prior to sinus augmentation surgery.MethodsFrom the 177 patients who underwent sinus augmentation with lateral approach at Ewha Womans University Department of Implant Dentistry, 284 CT scans were evaluated. The canal height (CH), ridge height (RH), and canal height from the sinus floor (CHS) were measured on para-axial views at the first premolar, first molar, and second molar. The horizontal positions of the bony canals in the lateral wall were also classified. One-way analysis of variance (ANOVA) and t test were used to estimate the statistical differences (p < 0.05).ResultsThe intraosseous loops were detected in 92 CT scans (32 %). The mean vertical height of the bony canals from the alveolar crest (CH) was 23.45 ± 2.81, 15.92 ± 2.65, and 16.61 ± 2.92 mm at the second premolar, first molar, and second molar, respectively. In the horizontal positions of the bony canals, intraosseous type was the most predominant. The canal heights more than 15 mm and less than 17 mm were most prevalent (33.7 %) and those under 13 mm were 12.0 %.ConclusionsThe radiographic findings in this study could be used to decide the lateral osteotomy line avoiding potential vascular complication. However, only one third of the canals could be detected in CT scans; a precaution should be taken for the possibility of severe bleeding during lateral osteotomy.

Evaluation of the nasopalatine canal with cone-beam computed tomography in an Iranian population.

Implant placement plays a vital role in oral rehabilitation following loss of the incisors. Thus, having knowledge of anatomical variations of adjacent neurovascular structures especially the nasopalatine canal (NPC) is essential. Due to the lack of basic information in Iran about the morphology of this canal and the probability of its variety in different populations, this study was designed on an Iranian population. In this descriptive study, we selected cone-beam computed tomography images of 198 patients comprising of 98 males and 100 females in two dental groups (edentulous or dentate). The shape of the nasopalatine foramen and the form of the canal in axial views were assessed. Then, the canal height and its diameter at the palatal, middle and nasal levels in cross-sectional images were measured. The available bone in the buccal and palatal sides of the canal was assessed. Data analysis was carried out using a Chi-square test and an independent t-test (P ≤ 0.05). The majority of the samples (81.8%) presented a single foramen. Cylindrical shape (57.6%) was the most frequently detected canal form. The mean of the estimated canal height was 12.84 ± 2.88 mm. The canal diameter at the palatal level between the sexes and dental groups showed statistically significant differences. In our investigated population, the NPC form was mainly cylindrical with a single opening foramen. The mean of the canal height was higher than that found in other populations. Furthermore, the canal diameter in the edentulous group was greater than that observed in the other group.

L4 fractures, biomechanics of cure foretold

Objectives: To analyze the clinical and radiographic outcomes in fracture of the fourth lumbar vertebra, under conservative or surgical treatment. Methods: Patients diagnosed with L4 fracture with or without neurological injury were studied and to whom conservative or surgical treatment was provided. Radiographic measurements were performed taking into account the kyphosis angle, the sagittal index, loss of vertebral body height, percentage of canal occlusion and height compression percentage. Results: Twenty-five patients were treated, five conservatively and 20 surgically. The vertebral kyphosis angle in both groups was 12&amp;#176;, no regional kyphosis was present, the sagittal index was 11.9 (Farcy), the loss of vertebral body height was 53.17%, the percentage of canal occlusion was 23% and the height compression percentage was 38.06%. The residual pain according to the visual analog scale was two in both groups. Conclusions: Patients with a fractured L4 have a satisfactory outcome with both treatments, the height of the vertebral body remains the same, the lordosis is preserved and therefore the sagittal balance, allowing recovering the mechanical functions of the spine as opposed to other segment fractures.

Evaluation of the effect of feed canal height on membrane clarification efficiency of pomegranate juice using computational fluid dynamics (CFD)

Pomegranate juice in its turbid appearance is difficult to preserve; hence, it should be clarified. Microfiltration is a pressure-driven process which can be used to clarify pomegranate juice. Computational fluid dynamics was used to simulate the effect of feed canal height on efficiency of the membrane clarification of pomegranate juice. Geometry of membrane unit was plotted in Gambit software and meshed with quad-mapped meshes, and the problem was solved using FLUENT software. Boundary conditions were identified in both Gambit and FLUENT. Two-dimensional double precisions procedure was selected in FLUENT software. Selected solver was segregated one at steady state. Membrane was defined with three parameters in FLUENT including face permeability, membrane thickness, and pressure jump coefficient. Results of simulation showed that permeate volume was directly dependent on feed canal height. Experimental results were in agreement with the results which were obtained from simulation.

Effect of Feed Canal Height on the Efficiency of Membrane Clarification of Pomegranate Juice

There are several parameters which affects the efficiency of membrane clarification of fruit juices, such as feed temperature, transmembrane pressure (TMP) and feed velocity. Pomegranate juice undergone the clarification process in a microfiltration unit at different feed canal heights (FCH; 0.4, 1.5 and 2 cm) to evaluate its effect on the permeate flux and fouling mechanism. Changes in permeate flux, main fouling mechanism and occurrence time of each fouling mechanism were evaluated. Results showed that increasing the FCH can increase permeate flux, total and irreversible fouling resistances duo to increase the feed volume on the membrane surface which can increase raw material of clarified juice. Also, cake formation was the dominant fouling mechanism in all membrane units; however, it occurs during the early stages of membrane processing at an FCH of 2 cm in contrast with 0.4 cm in which cake was produced at the steady state. Practical Applications Concentration of nonclarified pomegranate juice caused off flavor because of burn large particles on the walls of the evaporator. Microfiltration can be used to clarify pomegranate juice. To increase the efficiency of the clarification process, the feed canal height (FCH) in the flat sheet module was increased. Results showed that the amount of clarified juice can be increased by increasing the FCH. Also, washing the membrane at high velocity can repair its efficiency after juice treatment; because of the cake formation was the main fouling mechanism.

Comparison of magnetic resonance imaging with standing cervical radiographs for evaluation of vertebral canal stenosis in equine cervical stenotic myelopathy

The sensitivity and specificity of lateral cervical radiographs to evaluate horses suspected of cervical stenotic myelopathy (CSM) are limited by the assessment being restricted to the sagittal plane. To determine whether magnetic resonance imaging (MRI) allows for a more accurate identification of stenosis than lateral cervical radiographs in horses with CSM. Case control study. Nineteen Thoroughbred horses with CSM (17 males, 2 females, age 6-50 months) were compared to 9 control Thoroughbreds (6 males, 3 females, age 9-67 months). Ante mortem, the subjects had neurological examinations and standing cervical radiographs with sagittal ratios calculated from C3 to C7. Intact cervical column MRI scans and histological examinations of the spinal cord were performed post mortem. Morphometric parameters were measured on the vertebral canal, spinal cord and intervertebral foramen. Radiographic cervical canal height measurements categorised by standard minimal sagittal diameter intravertebral and intervertebral ratios produced several false positive and false negative determinations of canal stenosis as defined by spinal cord histopathology. Post mortem MRI measurements of canal area and cord canal area ratio more accurately predicted sites of cord compression in CSM cases. No differences in spinal cord measurements were observed when comparing CSM to control horses, but each of the vertebral canal parameters achieved significance at multiple sites. Vertebral canal area and cord canal area ratio are better parameters to predict the location of cervical canal stenosis compared to only the sagittal plane of canal height. Additional visual planes and measurements obtained by MRI, specifically vertebral canal area and the cord canal area ratio, will provide a more accurate method to identify regions of canal stenosis than lateral cervical radiographs. The development of MRI or computed tomography equipment capable of evaluating the cervical column of mature horses may substantially enhance evaluation of CSM patients. The Summary is available in Chinese - see Supporting information.

Is the vertebral canal prepared to host the aged spinal cord? A morphometric assessment

Fil: Nishida, Fabian. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - La Plata; Argentina

Skeletal morphology and morphometry of the lumbosacral junction in German shepherd dogs and an evaluation of the possible genetic basis for radiographic findings

The aim of this study was to identify skeletal variations in the lumbosacral junction (LSJ) of the German shepherd dog (GSD) compared with other large breeds. The radiographic traits of the LSJ were investigated in a group of 733 GSDs and a control group of 334 dogs of other breeds that were matched in terms of size. Nine morphological and 17 morphometric traits were recorded and analysed. Furthermore, the possibility of a genetic basis for these radiographic features was evaluated by calculation of genetic variance components. Five of the morphological and 14 of the morphometric traits varied significantly between the GSD group and the control group (P<0.05). Osteochondrosis of the sacral endplate (SOC) had a higher prevalence in the GSDs (10.1%) compared with controls (5.7%). The majority of LSJ degenerative changes recorded from the radiographs occurred in the GSDs. The extent and relative proportion of lumbosacral step formations were greater in the GSD group compared with controls (P<0.001). The lumbosacral vertebral canal height was reduced in the GSD compared with the control dogs (P<0.001) suggesting a primary stenosis. This was accentuated by an abrupt tapering of the vertebral canal at the level of the LSJ indicated by a lumbosacral ratio of 1.51 in the GSD. The skeletal morphology and morphometry of the LSJ in the GSD seem to be different from that found in other large dogs. For multiple traits frequently observed in GSD such as SOC, step formations, and LSJ stenosis, moderate to high non-zero heritabilities were noted. As these features are also assumed to promote lumbosacral disease, selection against these traits is suggested.