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1.
John R. Fike PhD Richard A. LeCouteur BVSc Christopher E. Cann PhD 《Veterinary radiology & ultrasound》1984,25(1):32-36
Computed tomography (CT) was used to study the normal anatomy of the orbital region in one Beagle. Direct transverse and reformatted dorsal, sagittal, and oblique plane images were used to distinguish various soft tissue structures. Intraorbital fat provided a natural contrast against which extraocular muscles and nerves could be discerned. The noninvasive nature and the multiplanar imaging capabilities of CT provided a means by which the orbital contents could be precisely localized and differentiated from one another. 相似文献
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Rhea V. Morgan DVM Robert L. Donnell DVM Gregory B. Daniel DVM MS 《Veterinary radiology & ultrasound》1994,35(5):362-367
Magnetic resonance images of a screech owl ( Otus asio ) were acquired to identify the normal anatomic components of the eye'and orbit. T1-weighted, proton-density, and T2-weighted images were obtained in the straight sagittal, oblique dorsal, and oblique sagittal planes. Signal intensity for the various orbital structures differed between the three resonance techniques. T1-weighted images provided the best anatomic detail of ocular and orbital structures. The oblique dorsal and oblique sagittal planes were superior for evaluating the optic nerve in its entirety. 相似文献
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Rhea V. Morgan DVM Gregory B. Daniel DVM MS Robert L. Donnell DVM 《Veterinary radiology & ultrasound》1994,35(2):102-108
Magnetic resonance (MR) images of the normal eye and orbit of the dog and cat were acquired. T1-weighted, proton-density, and T2-weighed images were obtained in the oblique dorsal, straight sagittal, and oblique sagittal planes. Signal intensity for the various orbital structures differed among the three resonance techniques. T1-weighted images provided the greatest contrast of the retrobulbar structures. T-1 weighted images also had the highest signal to noise ratio, thereby providing the best anatomic detail. Anatomic components of the globe, retrobulbar structures and ocular adnexa were easily seen in all MR sections. The oblique dorsal and oblique sagittal planes were superior for evaluating the optic nerve in its entirety. 相似文献
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Rhea V. Morgan DVM Rachel D. Ring DVM Daniel A. Ward DVM PhD William H. Adams DVM 《Veterinary radiology & ultrasound》1996,37(3):185-192
Magnetic resonance (MR) images were acquired in five dogs and one cat with ocular and orbital disease. MR images were obtained in the dorsal or oblique dorsal, and oblique sagittal planes. Pathologic changes identified in MR images included inflammatory lesions, cystic structures, and neoplasms. All abnormalities were readily apparent in TI-weighted images. MR findings in affected animals were often similar in signal intensity, location, and growth pattern to those found in people with comparable diseases. Although no MR changes were considered pathognomonic for a given disease, MR imaging provided detailed information on the homogeneity, extent and invasiveness of the lesions. 相似文献
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EYMERIC GOMES CHRISTOPHE DEGUEURCE YANNICK RUEL RUTH DENNIS DOMINIQUE BEGON 《Veterinary radiology & ultrasound》2009,50(4):398-403
Magnetic resonance (MR) images of the brain of four normal cats were reviewed retrospectively to assess the emergence and course of the cranial nerves (CNs). Two-millimeter-thick images were obtained in transverse, sagittal, and dorsal planes using a 1.5 T unit. CN skull foramina, as anatomic landmarks for MR imaging, were identified by computed tomography performed on an isolated cat skull using thin wire within each skull foramen. Thin slice (1 mm slice thickness) images were obtained with a high-resolution bone filter scan protocol. The origins of CNs II, V, VII, and VIII and the group of IX, X, XI, and XII could be identified. The pathway and proximal divisions of CNs V were described. CNs III, IV, and VI were not distinguished from each other but could be seen together in the orbital fissure. CN V was characterized by slight contrast enhancement. 相似文献
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ANATOMICAL STUDY OF CRANIAL NERVE EMERGENCE AND SKULL FORAMINA IN THE HORSE USING MAGNETIC RESONANCE IMAGING AND COMPUTED TOMOGRAPHY 
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下载免费PDF全文 Rita Gonçalves Fernando Malalana James Fraser McConnell Thomas Maddox 《Veterinary radiology & ultrasound》2015,56(4):391-397
For accurate interpretation of magnetic resonance (MR) images of the equine brain, knowledge of the normal cross‐sectional anatomy of the brain and associated structures (such as the cranial nerves) is essential. The purpose of this prospective cadaver study was to describe and compare MRI and computed tomography (CT) anatomy of cranial nerves' origins and associated skull foramina in a sample of five horses. All horses were presented for euthanasia for reasons unrelated to the head. Heads were collected posteuthanasia and T2‐weighted MR images were obtained in the transverse, sagittal, and dorsal planes. Thin‐slice MR sequences were also acquired using transverse 3D‐CISS sequences that allowed mutliplanar reformatting. Transverse thin‐slice CT images were acquired and multiplanar reformatting was used to create comparative images. Magnetic resonance imaging consistently allowed visualization of cranial nerves II, V, VII, VIII, and XII in all horses. The cranial nerves III, IV, and VI were identifiable as a group despite difficulties in identification of individual nerves. The group of cranial nerves IX, X, and XI were identified in 4/5 horses although the region where they exited the skull was identified in all cases. The course of nerves II and V could be followed on several slices and the main divisions of cranial nerve V could be distinguished in all cases. In conclusion, CT allowed clear visualization of the skull foramina and occasionally the nerves themselves, facilitating identification of the nerves for comparison with MRI images. 相似文献
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SUSANNE A. E. B. BOROFFKA CHRISTIANE GÖRIG EDUARDO AURIEMMA MAARTJE H. A. C. PASSON‐VASTENBURG GEORGE VOORHOUT PAUL Y. BARTHEZ 《Veterinary radiology & ultrasound》2008,49(6):540-544
We describe the magnetic resonance (MR) imaging aspects of normal canine optic nerve, the diameter of the optic nerve as measured on MR images, and optimal MR sequences for the evaluation of the optic nerve using a 0.2 T MR unit. Three millimeter contiguous slides of the normal canine orbital region were acquired in transverse and dorsal oblique planes using a variety of tissue weighting sequences. It was apparent that detailed anatomic assessment of the optic nerve can be performed with low‐field MR imaging, but none of the sequences provided unequivocal superior image quality of the optic nerve. The mean diameter of the optic nerve sheath complex was 3.7 mm and of the optic nerve 1.7 mm. The intraorbital and intracanalicular parts of the optic nerve are consistently visible and differentiation between the optic nerve and optic nerve sheath complex is possible using low‐field MR systems. 相似文献
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Computed Tomography and Magnetic Resonance Anatomy of the Normal Orbit and Eye of the Horse 下载免费PDF全文
下载免费PDF全文 C. D'Août J. F. Nisolle M. Navez R. Perrin T. Launois L. Brogniez P. Clegg F. Hontoir J. M. Vandeweerd 《Anatomia, histologia, embryologia》2015,44(5):370-377
Traumatic and infectious diseases of the eye and orbit can occur in horses. For diagnosis and monitoring of such diseases, medical imaging is useful including computed tomography (CT) and magnetic resonance imaging (MRI). The aim of the current study was to describe CT and MRI anatomy of the equine orbit and ocular globe. The heads from four adult horses were scanned with a 6‐slice Emotion 6 CT (Siemens, Erlangen), and a 3.0 Tesla Siemens Verio 6 MRI using T1 and T2‐weighted sequences. To validate CT and MR reference images, these were compared with anatomical models and gross anatomical sections. The bony limits of the orbital cavity, the relationship of the orbit with sinuses and foramina of the skull were well identified by CT. MRI was useful to observe soft tissues and was able to identify adnexae of the ocular globe (eyelids, periorbital fat, extraocular muscles, lacrymal and tarsal glands). Although MRI was able to identify all components of the eye (including the posterior chamber), it could not differentiate sclera from choroid and retina. The only nerve identified was the optic nerve. Vessels were not seen in this series of cadaver heads. This study showed that CT and MRI are useful techniques to image the equine orbit and eye that can have clinical applications. 相似文献
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Laurent Couturier Christophe Degueurce Yannick Ruel Ruth Dennis Dominique Begon 《Veterinary radiology & ultrasound》2005,46(5):375-383
Twenty-two magnetic resonance imaging (MRI) brain studies of different breeds of dogs were reviewed to assess the anatomy of cranial nerve (CN) origins and associated skull foramina. These included five anatomic studies of normal brains using 2-mm-thick slices and 17 studies using conventional clinical protocols with 3- or 4-mm slices on both normal and abnormal brains. Images were obtained in transverse, sagittal, and dorsal planes to allow a thorough comparison between studies. CNs II, III, V (and its divisions), and VIII were observed consistently on conventional studies. On the thin-slice studies, the origins and proximal portions of CNN IV, VII, and the group of IX, X, and XI could be seen. The origins of CNN VI and XII were not observed with certainty. In parallel, a computed tomography study of an isolated skull was performed with a thin copper wire within each of the skull foramina to determine precisely each CN exit and to facilitate recognition of the course of CNs when exiting the skull on MRI images. 相似文献
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Computed tomographic (CT) imaging of eight normal cadaveric canine stifles was performed before and after intra-articular administration of iodinated contrast medium. Transverse CT images were reconstructed in dorsal, parasagittal, and oblique planes. The following ligamentous structures were identified on transverse CT images in all stifles: cranial cruciate ligament, caudal cruciate ligament, medial meniscus, lateral meniscus, and the medial and lateral collateral ligaments. The following ligamentous structures were identified on transverse computed tomographic arthrography (CTA) images in all stifles: cranial cruciate ligament, caudal cruciate ligament, medial meniscus, lateral meniscus, meniscofemoral ligament, cranial meniscotibial ligaments, caudal meniscotibial ligaments, intermeniscal (transverse) ligament, and the medial and lateral collateral ligaments. The patellar tendon was identified on transverse and reconstructed dorsal and sagittal CT and CTA images in all stifles. Multiplanar reconstructions enabled further evaluation of the continuity of the cranial and caudal cruciate ligaments and menisci. The medial and lateral collateral ligaments were not clearly identified on CT or CTA multiplanar reconstructed images. 相似文献
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Ultrasonographic or anatomic observations or both were made of the kidneys of 26 dogs. The anatomic studies established precise correlations between the gross anatomic features of the organ and its ultrasonographic images obtained in transverse, sagittal, dorsal, and 2 oblique planes. Uniformly mottled echogenicity of the renal cortex could be clearly differentiated from the less echogenic renal medulla. In the mid-dorsal plane, the papillae of the renal pyramids were directed towards the renal sinus. The bases of the pyramids were almost circular in outline in the midsagittal images and the renal crest was seen as an echogenic line. Although the renal sinus was highly echogenic, neither the renal pelvis nor its recesses were detected. The walls of each of the interlobar arteries provided echogenic parallel lines, passing in the renal recesses between the renal pyramids. Arcuate arteries were demonstrated at the corticomedullary junction and interlobular arteries were detected within the renal cortex. For the right kidney, transverse images were obtained with the ultrasonographic transducer at the last 2 intercostal spaces; images in the dorsal, sagittal, and oblique planes were obtained with the transducer placed over the caudal extremity of the kidney. In the left kidney, transverse images were made with the transducers at, and caudal to, the last intercostal space; images in the dorsal, sagittal, and oblique planes were obtained with the transducer placed over the lateral border of the kidney. The use of such a protocol ensures that the entire organ is inspected and a diagnosis of either a normal or pathologic kidney is made. 相似文献
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MAGNETIC RESONANCE IMAGING FEATURES OF ORBITAL INFLAMMATION WITH INTRACRANIAL EXTENSION IN FOUR DOGS
SIBYLLE KNEISSL MARTIN KONAR REA FUCHS-BAUMGARTINGER BARBARA NELL 《Veterinary radiology & ultrasound》2007,48(5):403-408
This retrospective study describes the clinical and magnetic resonance (MR) imaging features of chronic orbital inflammation with intracranial extension in four dogs (two Dachshunds, one Labrador, one Swiss Mountain). Intracranial extension was observed through the optic canal (n=1), the orbital fissure (n=4), and the alar canal (n=1). On T1-weighted images structures within the affected skull foramina could not be clearly differentiated, but were all collectively isointense to hypointense compared with the contralateral, unaffected side, or compared with gray matter. On T2-, short tau inversion recovery (STIR)-, or fluid-attenuated inversion recovery (FLAIR)-weighted images structures within the affected skull foramina appeared hyperintense compared with gray matter, and extended with increased signal into the rostral cranial fossa (n=1) and middle cranial fossa (n=4). Contrast enhancement at the level of the affected skul foramina as well as at the skull base in continuity with the orbital fissure was observed in all patients. Brain edema or definite meningeal enhancement could not be observed, but a close anatomic relationship of the abnormal tissue to the cavernous sinus was seen in two patients. Diagnosis was confirmed in three dogs (one cytology, two biopsy, one necropsy) and was presumptive in one based on clinical improvement after treatment. This study is limited by its small sample size, but provides evidence for a potential risk of intracranial extension of chronic orbital inflammation. This condition can be identified best by abnormal signal increase at the orbital fissure on transverse T2-weighted images, on dorsal STIR images, or on postcontrast transverse or dorsal images. 相似文献
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Tromblee TC Jones JC Bahr AM Shires PK Aref S 《American journal of veterinary research》2007,68(8):858-871
OBJECTIVE: To test the effects of computed tomography (CT) image plane and window settings on diagnostic certainty for CT characteristics associated with dysplastic elbow joints (elbow joint dysplasia) in dogs and to provide optimal display guidelines for these CT characteristics. SAMPLE POPULATION: CT images of 50 dysplastic elbow joints from 49 lame dogs and 10 elbow joints from 5 sound dogs. PROCEDURES: CT image data were obtained in transverse, sagittal, and dorsal planes. Each plane was examined by use of 3 Hounsfield unit (HU) window settings. Two veterinary radiologists independently evaluated sets of CT images for evidence of 7 CT characteristics. Effect of elbow joint status, image plane, and window settings on diagnostic certainty for these CT characteristics was tested by use of a visual analogue scale. RESULTS: Diagnostic certainty for abnormalities of the medial coronoid process (MCP) and radial incisure was highest in the transverse plane, subchondral defects or sclerosis of the trochlea humeri was highest in the dorsal plane, and joint incongruity was highest in the sagittal plane. Certainty for hypoattenuating subchondral defects or fissures was highest at 2,500 or 3,500 HUs, whereas certainty for subchondral sclerosis was highest at 1,500 HUs and lowest at 3,500 HUs. CONCLUSIONS AND CLINICAL RELEVANCE: Diagnostic certainty for CT characteristics of elbow joint dysplasia in dogs was affected by image display variables. Diagnostic certainty for altered subchondral bone density was primarily influenced by window settings, whereas structural MCP abnormalities and joint incongruity were influenced most by image plane. 相似文献
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Holsworth IG Wisner ER Scherrer WE Filipowitz D Kass PH Pooya H Larson RF Schulz KS 《Veterinary surgery : VS》2005,34(2):108-113
OBJECTIVE: To evaluate the accuracy of linear measurements obtained from computer tomography (CT) images of staged radio-ulnar incongruence in a canine cadaver forelimb model. STUDY DESIGN: CT evaluation of induced progressive radio-ulnar incongruence in canine cadaveric forelimbs. SAMPLE POPULATION: Eight cadaveric canine left forelimbs. PROCEDURE: A type 2 external skeletal fixator (ESF) with linear motors was attached to the radius in 8 cadaveric left canine forelimbs. Contiguous incremental and helical CT images of the proximal radio-ulnar articulation were acquired in the transverse, sagittal and dorsal planes. The radius was shortened by 1, 2, and 4 mm increments and scanning protocols were repeated at each increment. Digital caliper and CT image analysis measured the progressive change in distance between 2 marking spheres and the epiphyseal bone surfaces of the radio-ulnar articulation. Statistical analysis of measurements from incremental and helical CT acquisitions, and direct and reformatted images were compared with inter-sphere distance using Pearson product moment correlation coefficients. RESULTS: The reformatted incremental acquisition series at the mid-coronoid in the oblique plane had the highest correlation coefficient (r-value) at 0.908. The mid-coronoid in the dorsal plane had the second highest r-value (0.856). The coronoid incisure in the sagittal plane had an r-value of 0.826. The reformatted incremental acquisition series at the coronoid incisure in the oblique plane had the lowest r-value, 0.592. CONCLUSION: Measurement of radioulnar incongruence may be best performed using reformatted incremental acquisition CT in the mid-coronoid region in an oblique plane. CLINICAL RELEVANCE: Use of the technique reported in this study may enable determination of the association, if any, between radioulnar incongruence and developmental diseases of the canine elbow. 相似文献
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Stephen Joslyn Suzanna Richards Susanne Boroffka Mark Mitchell Gawain Hammond Martin Sullivan 《Veterinary radiology & ultrasound》2014,55(1):63-67
Enhancement of extra‐ocular muscles has been reported in cases of orbital pathology in both veterinary and medical magnetic resonance imaging. We have also observed this finding in the absence of orbital disease. The purpose of this retrospective study was to describe extra‐ocular muscle contrast enhancement characteristics in a group of dogs with no known orbital disease. Magnetic resonance images (MRI) from dogs with no clinical evidence of orbital disease and a reportedly normal MRI study were retrieved and reviewed. Contrast enhancement percentages of the medial, lateral, ventral, and dorsal rectus muscles were calculated based on signal‐to‐noise ratios that were in turn determined from hand‐traced regions of interest in precontrast, immediate postcontrast and 10‐min postcontrast scans. Comparison measurements were made in the pterygoid muscle. Contrast enhancement of the extra‐ocular muscles was observed in all patients (median contrast enhancement percentage 45.0%) and was greater than that of pterygoid muscle (median contrast enhancement percentage 22.7%). Enhancement of the extra‐ocular muscles persisted 10 min after contrast administration (median contrast enhancement percentage 43.4%). Findings indicated that MRI contrast enhancement of extra‐ocular muscles is likely normal in dogs. 相似文献
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Alberto Arencibia DVM PhD Jose M. Vazquez DVM PhD Juan A. Ramirez MD PhD Gregorio Ramirez DVM PhD Jose M. Vilar DVM Miguel A. Rivero DVM Santiago Alayon MD Francisco Gil DVM PhD 《Veterinary radiology & ultrasound》2001,42(5):405-408
The purpose of this investigation was to define the magnetic resonance (MR) imaging appearance of the brain and associated structures of the equine head. MR images were acquired in oblique dorsal (T2-weighted), sagittal (T1-weighted), and transverse planes (T2-weighted), using a magnet of 1.5 Tesla and a human body coil. Relevant anatomic structures were identified and labeled at each level. The resulting images provided excellent anatomic detail of the cranioencephalic structures. Annotated MR images from this study are intended as a reference for clinical imaging studies of the equine head, specially in the diagnosis of brain diseases in the horse. 相似文献