PubMed Health⌕ Search

Biomedical subjects

J T Hathcock

Publications and source records attributed to J T Hathcock.

At least 19 recordsLinked to original sources
PubMed1993

Principles and concepts of computed tomography.

The final CT image is actually made of a grid of tiny squares called pixels. The scale of grays assigned to each pixel represents the attenuation of x-rays by the structures in the tomographic slice. Manipulation of the gray scale allows optimal visualization of all the tissues within the slice. This control over the gray scale and the absence of structure superimposition are the advantages of CT over conventional x-ray techniques. The steps used to acquire the final CT image are collection of data from the patient (recording of transmitted x-ray intensities from many angles), computer processing of data (mathematical calculation of attenuation of each structure in the tomographic slice), image display (assigning of appropriate gray scale to CT image to evaluate all structures), and data storage (recording series of tomographic images on x-ray film and archiving image data for later review). Common image artifacts that must be identified and interpreted as such include aliasing, ring artifacts, beam hardening effect, metal, motion, partial volume averaging, and streaking from out-of-field objects.

Animals↗
PubMed1993

Interpretation of computed tomographic images.

This article discusses the production of optimal CT images in small animal patients as well as principles of radiographic interpretation. Technical factors affecting image quality and aiding image interpretation are included. Specific considerations for scanning various anatomic areas are given, including indications and potential pitfalls. Principles of radiographic interpretation are discussed. Selected patient images are illustrated.

Animals↗
PubMed1990

Metastatic thyroid solid-follicular carcinoma in the cervical portion of the spine of a dog.

A metastatic thyroid solid-follicular carcinoma in the cervical portion of the spine was responsible for severe tetraparesis in a dog. Myelography revealed an extradural compressive lesion dorsal and to the right of the midline of C3. Histologic examination was used to diagnose the mass as a solid-follicular thyroid carcinoma. The primary tumor was not evident on cervical palpation or radiography. A dorsal laminectomy centered over C3 was performed, and all visible tumor was removed from the spine. The owner declined any further treatment for the dog.

Adenocarcinoma↗
PubMed1990

Hip dysplasia with bilateral ischiatic nerve entrapment in a dog.

Dysfunction of both ischiatic nerves was detected in a 5-year-old spayed Labrador Retriever with radiographic evidence of severe bilateral hip dysplasia. Marked hyperflexion of the hip and stifle was evident when the dog walked. Results of electromyography confirmed the ischiatic nerve involvement. At staged operations, both ischiatic nerves were found to be compressed between the sacrotuberous ligament and proliferative tissue around the hip. One year after surgery, electromyographic and physical findings were essentially normal.

Animals↗
PubMedDate not supplied

A symmetric axis-based method for measuring the projected femoral angle of inclination in dogs.

A new, simple and more consistent method for measuring the projected angle of inclination of the canine femoral neck was devised and tested. This method, based on the principles of symmetric axis (symax) shape analysis, was compared with three other techniques currently in use. Diplomates of the ACVR or ACVS and senior veterinary students were asked to perform measurements of the angle of inclination using the four methods, record their results, and answer several questions about the techniques. Although greater precision was not evident when performed by diplomates, descriptive statistics and a significant difference among the student-derived variances of the four methods demonstrated that the symax-based measurements were most consistent.

Analysis of Variance↗
PubMedDate not supplied

Radiographic, computed tomographic and magnetic resonance imaging evaluation of a chronic long digital extensor tendon avulsion in a dog.

Long digital extensor tendon avulsion is reported in a 5 month old Great Dane. Clinically the dog presented with a unilateral weight-bearing pelvic limb lameness. Joint effusion was present and there was pain and crepitance associated with flexion of the stifle. Orthopedic evaluation and radiographs were suggestive of a long digital extensor tendon injury which was confirmed by computed tomography and magnetic resonance imaging. The injury was surgically repaired with screw and spiked washer fixation.

Animals↗