PubMed Health⌕ Search

Biomedical subjects

J A Shipley

Publications and source records attributed to J A Shipley.

7 recordsLinked to original sources

Automated quantitative volumetric breast ultrasound data-acquisition system.

This paper describes the development and initial testing of an automated ultrasound imaging technique to acquire quantitative volumetric breast data; the clinical application being breast cancer diagnosis and management. A novel mechanical scanner has been designed and constructed to constrain the breast tissue without compromising the image, to acquire images of the majority of the breast using a conventional B-mode scanner and to maintain patient comfort. An algorithm to improve upon simple depth-dependent amplification by compensating for tissue-dependent attenuation is applied to the images, making the grey-scale values represent local scattering properties more closely. Registration techniques have been developed to correct for geometric errors arising in the data set because of tissue movement and variations in speed of sound in the tissues. The data sets are reconstructed into volumes and viewed interactively. A pilot study of seven patients was performed and selected results are presented to illustrate lesion features. The automated scan reduces operator-dependence, provides clear information on the 3-D tissue boundaries and provides a full record for monitoring or surgical planning.

Algorithms↗

The diagnosis of skeletal tuberculosis by polymerase chain reaction.

OBJECTIVE: To determine the potential of the polymerase chain reaction (PCR) for detecting Mycobacterium tuberculosis in skeletal samples by comparing results obtained by 1) Ziehl Neelsen staining, Lowenstein-Jensen and Bactec culture, 2) histopathology and clinical findings at the level of agreement, sensitivity and specificity. DESIGN: Cross sectional study. SETTING: Department of Medical Microbiology, Orthopaedics and Anatomical pathology, University of the Orange Free State Bloemfontein, South Africa. SUBJECTS: 45 consecutive patients were extensively investigated, 30 patients with clinical presumptive active tuberculosis and 15 with other pathology. RESULTS: Detection using culture could confirm only three of the 26 clinically diagnosed tuberculosis cases while PCR detection confirmed disease in 15 cases. The use of PCR increased the confirmation of clinically probable tuberculosis from 14 using standard laboratory techniques and histology to 18 of 26 cases. Calculated sensitivity and specificity for PCR employing culture as the "gold standard" were 100% (with 95% CI 29.2; 100.0) and 71.4% (55.4; 84.3), which due to low detection levels, basically excludes culture as a standard for statistical analysis. Sensitivity and specificity for PCR using histology as the "gold standard" were 78.6% (49.2; 95.3) and 87.1% (70.2; 96.4) respectively with positive and negative predictive values of 73.3% (44.9; 92.2) and 90% (73.5; 97.9) respectively. Positive agreement between PCR and histology was 0.64 (0.4; 0.9) indicating fair agreement. CONCLUSION: Although numbers in the study were too low to effectively draw statistically valid conclusions the importance of the relevance of PCR for rapid detection of low numbers of acid-fast bacilli and confirmation of mycobacterial infection in spinal biopsies has been established.

Bacteriological Techniques↗

The nature of the spondylolytic defect. Demonstration of a communicating synovial pseudarthrosis in the pars interarticularis.

We injected methylene blue dye into 32 of the facet joints immediately above the defects in 17 consecutive patients with bilateral spondylolysis (34 defects). In 30 of these the dye flowed into a central cavity in the defect of the pars interarticularis and in 20 it passed into the facet joint below the defect. We found macroscopic cavities in 32 of the defects which communicated with the adjacent facet joints and had fibrous capsules. Histological examination showed focal areas of synovial lining consistent with a synovial pseudarthrosis. In most patients requiring surgery for spondylolysis, the defect is a synovial pseudarthrosis which communicates with the facet joint above it, and less often with the facet joint below it. We suggest that stress fractures of the pars may fail to heal because of the presence of synovial fluid from a nearby facet joint.

Adult↗

Myositis ossificans progressiva. A case report.

The clinical and laboratory features of a case of myositis ossificans progressiva are described, and the recent literature concerning the pathogenesis and treatment of the condition is briefly reviewed.

Adult↗