Search Results

You are looking at 1 - 5 of 5 items for

  • Author or Editor: Paul J. Simoens x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract

Objective—To provide a detailed anatomic description of the thorax in clinically normal dogs by means of computed tomography.

Animals—4 clinically normal adult German Shepherd Dogs weighing 28 to 37 kg.

Procedure—Dogs were anesthetized and positioned in ventral recumbency for computed tomographic (CT) examination of the thorax. A CT image from the thoracic inlet to the diaphragm was made by use of a third-generation scanner with a slice thickness of 5 mm. Individual images were reviewed by use of soft tissue (window width, 250 Hounsfield units; window level, 35 Hounsfield units) and lung (window width, 1,000 Hounsfield units; window level, –690 Hounsfield units) settings. One dog, weighing 28 kg, was euthanatized, bound on a wooden frame in the same position as used for CT examination, and frozen at –14oC until solid. By use of an electric band saw, the frozen thorax was sectioned at 10-mm-thick intervals. Slab sections were immediately cleaned, photographed, and compared with corresponding CT images.

Results—Anatomic sections were studied, and identified anatomic structures were matched with structures on corresponding CT images. Except for some blood vessels and details of the heart, most of the bony and soft tissue structures of the thorax discerned on anatomic slices could be found on matched CT images.

Conclusions and Clinical Relevance—Because CT images provide detailed information on most structures of the canine thorax, results of our study could be used as a guide for evaluation of CT images of the thorax of dogs with thoracic diseases. (Am J Vet Res 2005;66:512–524)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To use computed tomography to provide a detailed description of tarsal joint structures in clinically normal dogs.

Animals—6 clinically normal adult mixed-breed dogs weighing 25 to 35 kg and one 12-month-old Bullmastiff weighing 65 kg.

Procedure—To perform computed tomography (CT) of both tarsal regions, dogs were anesthetized and placed in ventral recumbency. One- and 2-mm contiguous slices were obtained, using a third generation CT scanner. Individual images were reviewed, using bone (window width = 3,500 Hounsfield units; window level = 500 Hounsfield units) and soft-tissue (window width = 400 Hounsfield units; window level = 66 Hounsfield units) settings. After euthanasia, the hind limbs from the Bullmastiff were removed and frozen at –18 C. Tarsal joints were sectioned into approximately 1-mmthick slab sections, using a cryomicrotome. Anatomic sections were photographed and compared with the corresponding CT images. Computed tomographic reconstructions of the tarsocrural joint were created in sagittal and dorsal planes.

Results—Structures on the CT images were matched with structures in the corresponding anatomic sections. The entire tarsocrural joint surface could be evaluated on the reconstructed images in the sagittal and dorsal planes.

Conclusions and Clinical Relevance—CT images provide full anatomic detail of the bony structures of the tarsal joint in dogs. Tendons and large blood vessels can also be evaluated. These results could be used as a basis for evaluation of CT images of the hind limbs of dogs with tarsal joint injuries. (Am J Vet Res 2001;62:1911–1915)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To provide a detailed anatomic description of brain structures in clinically normal dogs by means of computed tomography (CT).

Animals—4 clinically normal adult German Shepherd Dogs weighing 30 to 35 kg.

Procedure—Each dog was anesthetized and positioned in ventral recumbency for CT examination of the brain; transverse scans were completed at 2-mm intervals from the cribriform plate of the ethmoid bone to the cranial part of the atlas by use of a thirdgeneration CT scanner. Contrast material was injected IV, and a second series of scans was completed. Images (with or without contrast) from all dogs were reviewed by use of a soft tissue setting (window width, 150 Hounsfield units; window level, 50 Hounsfield units). One of the dogs was euthanatized, and a 3.5% formaldehyde solution was perfused via the common carotid arteries. After fixation, the brain was embedded in gelatin and sectioned into 5-mm thick transverse sections by use of a stainless-steel knife. Anatomic sections were photographed and compared with the corresponding CT views.

Results—Most features of the brain that were identified on anatomic sections could be identified on the corresponding CT scans despite the low contrast between structures, particularly if adjacent bony and soft tissue structures were used as landmarks. Additional anatomic structures surrounding the brain were also identifiable on the CT images.

Conclusions and Clinical Relevance—Images obtained in this study could be used as a guide for evaluation of CT images of the brain in dogs with brain diseases. (Am J Vet Res 2005;66;1743–1756)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To use computed tomography (CT) and magnetic resonance imaging (MRI) to provide a detailed description of the nasal cavities and paranasal sinuses in clinically normal mesaticephalic dogs.

Animals—2 clinically normal Belgian Shepherd Dogs that weighed 25 and 35 kg, respectively.

Procedure—The first dog was anesthetized and positioned in ventral recumbency for CT and MRI examinations, and transverse slices were obtained from the caudal part of the frontal sinuses to the nares. For MRI, T1-weighted, T2-weighted, and proton-density sequences were obtained. The second dog was anesthetized and positioned in dorsal recumbency with the head perpendicular to the table, and CT and MRI examinations were again conducted. At the completion of the MRI examination, each dog received an IV injection of heparin and then was euthanatized. A 4% solution of formaldehyde was perfused IV immediately after each dog was euthanatized. The skull was prepared, decalcified, embedded with gelatin, and sectioned into 5-mmthick sections by use of a stainless-steel knife. Each anatomic section was photographed and compared with the corresponding CT and MRI views.

Results—Structures on the CT and MRI views matched structures on the corresponding anatomic sections. The CT scans provided good anatomic detail of the bony tissues, and MRI scans were superior to CT scans for determining soft-tissue structures.

Conclusions and Clinical Relevance—CT and MRI provide a means for consistent evaluation of all structures of the nasal cavities and frontal sinuses. Both techniques could be useful for evaluation of diseases that affect the nasal region. (Am J Vet Res 2003;64:1093–1098)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To use computed tomography (CT) to provide a detailed description of elbow joint structures in clinically normal dogs.

Animals—6 clinically normal adult mixed-breed dogs weighing 24 to 37 kg and one 12-month-old Labrador Retriever weighing 27 kg.

Procedure—To perform CT of both elbow regions, dogs were anesthetized and placed in lateral recumbency. One- and 2-mm contiguous slices were obtained by use of a third generation computed tomographic scanner. Good resolution and anatomic detail were acquired from the computed tomographic images by use of a bone (window width, 3,500 Hounsfield units; window level, 500 Hounsfield units) and soft-tissue setting (window width, 400 Hounsfield units; window level, 66 Hounsfield units). After euthanasia, the forelimbs from the Labrador Retriever were removed and frozen in water at –18oC. Elbow joints were sectioned into approximately 1- mm-thick slab sections by use of an electric planer. Anatomic sections were photographed and compared with the corresponding computed tomographic images. Computed tomographic reconstructions of the elbow joint were created in sagittal and dorsal planes.

Results—Structures on the computed tomographic images were matched with structures in the corresponding anatomic sections. The entire humeroradioulnar joint surface could be evaluated on the reconstructed images in the sagittal and dorsal plane.

Conclusions and Clinical Relevance—Computed tomographic images provide full anatomic detail of the bony structures of the elbow joint in dogs. Muscles, large blood vessels, and nerves can also be evaluated. These results could be used as a basis for evaluation of computed tomographic images of the forelimbs of dogs with elbow joint injuries. (Am J Vet Res 2002;63:1400–1407)

Full access
in American Journal of Veterinary Research