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Biomedical subjects

W B Morrison

Publications and source records attributed to W B Morrison.

At least 37 records · Page 2Linked to original sources
PubMed2000

Can imaging findings help differentiate spinal neuropathic arthropathy from disk space infection? Initial experience.

PURPOSE: To determine if radiographic, computed tomographic (CT), and magnetic resonance (MR) imaging findings can help differentiate spinal neuropathic arthropathy from disk space infection. MATERIALS AND METHODS: Imaging studies in 33 patients were evaluated, including 14 patients with spinal neuropathic arthropathy (12 radiographic, seven CT, and six MR studies) and 19 with disk space infection (13 radiographic, nine CT, and 12 MR studies). Potential imaging discriminators, including endplate sclerosis or erosions, osteophytes, spondylolisthesis, facet involvement (narrowing or erosions), vacuum disk, paraspinal soft-tissue mass, joint disorganization, and osseous joint debris, were recorded, as were MR imaging signal intensity and gadolinium-enhancement characteristics. RESULTS: The most helpful findings for diagnosis of spinal neuropathic arthropathy were vacuum disk on radiographs and CT images, debris on radiographs and CT and MR images, disorganization on radiographs and CT and MR images, facet involvement on radiographs and CT and MR images, spondylolisthesis on CT and MR images, diffuse signal intensity patterns in vertebral bodies on MR images, and rim enhancement of disks on gadolinium-enhanced MR images. Findings that were not helpful included endplate sclerosis and erosions, osteophytes, paraspinal soft-tissue mass, and decreased disk height. CONCLUSION: Vacuum disk, facet involvement, vertebral body spondylolisthesis, joint disorganization and debris, and gadolinium-enhancement patterns of vertebral bodies and disks may help differentiate spinal neuropathic arthropathy from infection.

Adult↗
PubMed2000

Complications of total hip arthroplasty: MR imaging-initial experience.

PURPOSE: To investigate the use of standard magnetic resonance (MR) imaging sequences with simple parameter modifications for the detection and characterization of total hip arthroplasty (THA) complications. MATERIALS AND METHODS: An initial phantom study was performed with cobalt-chrome and titanium prostheses to establish the imaging parameters for a subsequent clinical study. In the clinical study, coronal and transverse MR imaging of 14 THA prostheses was performed before and after intravenous contrast material administration in 12 patients who were being considered for revision arthroplasty. The images were reviewed for evidence of juxtaarticular or periprosthetic abnormalities, patterns of contrast enhancement, and quality of periprosthetic tissue depiction. RESULTS: Phantom study results showed improved periprosthetic tissue depiction with use of thin sections, increased frequency-encoding gradient strength, and fast spin-echo sequences. The clinical study results demonstrated periprosthetic abnormalities in 11 cases: mechanical loosening in two cases (including one case with an associated periprosthetic fracture); granulomatosis, eight; and infection, one. In 100% of cases, tissue depiction around the femoral component was judged to be of "diagnostic quality." Tissue depiction around the acetabular component was of diagnostic quality in five (36%) cases. In all seven surgically confirmed cases, a correct diagnosis was made preoperatively with MR imaging. CONCLUSION: By using simple modifications to standard MR imaging sequences, diagnostic-quality MR imaging of THA complications can be performed, particularly around the femoral prosthetic stem.

Acetabulum↗
PubMed2000

Direct MR arthrography of the shoulder: is exercise prior to imaging beneficial or detrimental?

PURPOSE: To define the beneficial and detrimental effects of adding exercise to direct magnetic resonance (MR) shoulder arthrography. MATERIALS AND METHODS: Direct, intraarticular, gadolinium arthrography of the shoulder was performed in 41 patients, who underwent 1.5-T MR imaging before and after 1 minute of arm swinging. Fourteen milliliters of dilute gadolinium solution was injected. Two readers blinded to exercise independently graded the randomly distributed images with a five-point scale for capsular contrast material resorption; extraarticular contrast material leakage; rotator cuff, glenoid labrum, and anterior capsule conspicuity; and partial-thickness or full-thickness rotator cuff tear and labral tear detectability. The sign test was performed to evaluate the significance of differences between preexercise and postexercise grading for each reader. A second review was performed, with direct side-by-side comparison of preexercise and postexercise images. RESULTS: There was evidence of increased capsular resorption after exercise but no alteration in the depiction of the rotator cuff tendons or glenoid labrum. There was no significant extraarticular contrast material leakage after exercise and no alteration in depiction of the anterior capsule. There was no difference in the detectability of rotator cuff or labral tears. CONCLUSION: Exercise with direct shoulder MR arthrography has no beneficial or detrimental effect on image quality or on the depiction of rotator cuff or labral tears.

Adolescent↗
PubMed2000

The histologic classification of 602 cases of feline lymphoproliferative disease using the National Cancer Institute working formulation.

Case information and histologic slides for 688 admissions of feline tissues from 12 veterinary institutions were assembled and reviewed to determine tissues obtained by biopsy or necropsy, age and sex of cat, tumor topography, feline leukemia viral antigen status, histologic frequency of mitoses, diagnosis, presence of necrosis, and presence and degree of sclerosis. Histologic sections were examined to place the lesions in one of the diagnostic categories of the National Cancer Institute working formulation (NCI WF) for lymphomas or lymphoid leukemia. Correlations between the various factors determined were tested using contingency tables and chi-square analysis to provide a statistical comparison between the levels of observations determined by case examination with the numbers expected from chance alone. Significant correlations (P < or = 0.05) were found between diagnosis and tumor topography, the frequency of mitoses, necrosis, sclerosis, and age, between mitoses and necrosis, topography, age, and feline leukemia viral infection status, between topography and necrosis and age, and between leukemia viral status and age. Significant correlations between diagnosis and tumor topography included a greater than expected number of cases of acute and chronic lymphoid leukemia and multicentric distribution of tumor. Small cell lymphomas were more frequent than expected in enteric and cutaneous areas and less frequent than expected in mediastinal, renal, and multicentric areas. In contrast, the high-grade small noncleaved type of lymphomas was found significantly more frequently than expected in the mediastinum and less frequently than expected in enteric tissues. In comparing diagnosis and frequency of mitoses, the lymphomas classified as low grade by the NCI WF were significantly more frequent than expected in the lower categories (0-2/100x) of mitoses, and those classified as high-grade lymphomas were more frequent than expected in the higher categories (4-8/1OOx) of mitoses. In comparing diagnosis and sclerosis, diffuse sclerosis was more frequent than expected for the intermediate grade lymphomas of mixed cell type and for the high-grade lymphomas of the immunoblastic polymorphous type. In comparing diagnosis and locally extensive necrosis, this feature was more frequently observed than expected for cases of intermediate grade lymphoma of the small-cleaved cell category and for the high-grade lymphoma of the immunoblastic cell type. In comparing mitoses and necrosis, the lower grade lymphomas were, in general, characterized by a lower frequency of mitoses and a lower incidence of necrosis then would be expected from chance alone. In contrast, the higher grade lymphomas were characterized by more frequent mitoses and a higher incidence of necrosis. In tests comparing mitoses and tumor topography, lymphomas of the alimentary tract were more frequently observed than expected in the category with the lowest level of mitoses (0-1/100x), whereas lymphomas of the mediastinum and kidney were more frequently observed than expected in the categories with a higher level (4-20/ 100x) of mitoses.

Animals↗
PubMed2000

The utility of screening chest radiographs for flight physicals.

Previous studies have shown low efficacy of screening chest radiographs in various populations. Findings of approximately 3,500 screening chest radiographs performed for flight duty were reviewed to determine the rate of detection of significant abnormalities. There were abnormal findings in 107 chest radiographs (3%). Fifty-five of these (1.6% of total), after additional evaluation, were found to be false positive. Only two medically significant conditions were found in the screening population. Based on our data, routine screening of flight duty applicants does not appear to be justified.

Adolescent↗
PubMed2000

MR imaging of ankle marrow.

In this article the authors have attempted to distinguish the varying types of marrow disorders by the imaging characteristics. This is a challenging area but quite rewarding because the images can often be very specific.

Ankle Injuries↗
PubMed1999

Fracture of the lateral process of the talus: appearance at MR imaging and clinical significance.

The case of a 59-year-old man with chronic lateral ankle pain following an inversion injury is presented. MR imaging performed to evaluate for soft tissue injury revealed an unsuspected fracture of the lateral process of the talus. The patient underwent surgical exploration of the fracture with debridement of adjacent loose bodies and is currently undergoing aggressive physical rehabilitation.

Fractures, Bone↗
PubMed1999

Extraskeletal osteochondroma of the foot.

A case of pathologically proven extraskeletal osteochondroma is presented with magnetic resonance imaging (MRI), computed tomography (CT), bone scan and radiographic findings. The diagnosis of extraskeletal osteochondroma should be considered when a discrete, ossified mass is localized in the soft tissues of the distal extremities. Nomenclature surrounding this entity is controversial and is discussed.

Adolescent↗
PubMed1999

Coccidioidomycosis--the airborne assault continues: an unusual presentation with a review of the history, epidemiology, and military relevance.

Despite remarkable advances in detection and therapy, coccidioidomycosis remains a persistent threat to military troops deployed in endemic areas. Pregnant women, immunocompromised hosts, and dark-skinned persons, particularly those of Filipino, African, Hispanic or Asian ancestry, are at greatest risk for disseminated coccidioidomycosis. The ethnically diverse military forces have susceptible active duty and reserve members stationed at or temporarily trained on bases located in endemic areas for Coccidioides immitis. Although the vast majority of infections with this organism are subclinical, unusual patterns of dissemination pose a diagnostic challenge. The military physician may be tasked with recognizing acute non-specific symptoms as well as bizarre, occult manifestations of coccidioidomycosis. We present a case of disseminated coccidioidomycosis in an active duty Caucasian male who presented with a right shoulder mass. Our patient is atypical in that he had disseminated disease although immunocompetent and Caucasian. Another unusual feature is that the mass was not preceded or accompanied by any other symptoms. We could find only two other reported cases of coccidioidomycosis presenting as a soft tissue mass, both in African-American patients. The epidemiology and history of coccidioidomycosis will be reviewed, with an emphasis on military populations. The insidious nature of coccidioidomycosis, the importance of early detection and treatment in decreasing morbidity and mortality, and the presence of large numbers of military members in the endemic areas make the lessons of this case particularly relevant for all flight surgeons.

Adult↗
PubMed1998

Osteomyelitis of the foot: relative importance of primary and secondary MR imaging signs.

PURPOSE: To determine the usefulness of primary and secondary magnetic resonance (MR) imaging signs of osteomyelitis. MATERIALS AND METHODS: MR imaging at 1.5 T was performed in 73 feet (62 patients) with clinical concern for osteomyelitis. Images were reviewed retrospectively and separately by two reviewers in a blinded fashion for primary (abnormal marrow signal intensity) and secondary (ulcer, cellulitis, soft-tissue mass, abscess, sinus tract, cortical interruption) signs associated with osteomyelitis. RESULTS: Of the 73 feet, 43 had osteomyelitis. Discordant marrow signal intensity between individual MR sequences was observed by reader 1 in six (8%) feet and by reader 2 in 15 (21%) feet. For primary signs, fast spin-echo short inversion time inversion-recovery and gadolinium-enhanced fat-suppressed T1-weighted images had the highest sensitivity, and T1-weighted and gadolinium-enhanced fat-suppressed T1-weighted images had the highest specificity and least interobserver variability. Signs of cutaneous ulcer, sinus tract, and cortical interruption had the highest positive predictive value for osteomyelitis; signs of soft-tissue mass and cortical interruption had the highest negative predictive value. All had good interobserver agreement except cellulitis. CONCLUSION: When osteomyelitis of the foot is suspected, marrow signal intensity can differ on different types of MR images. Identification of secondary signs may augment diagnostic confidence when abnormal marrow signal intensity is seen.

Aged↗
PubMed1997

The effect of training and experience on the magnetic resonance imaging interpretation of meniscal tears.

To evaluate the effects of experience and training in the magnetic resonance imaging (MRI) diagnosis of meniscal tears 30 consecutive patients (60 menisci) in whom MRI of the knee with arthroscopic confirmation of meniscal status were studied. MRIs were interpreted by 10 reviewers of varying levels of training and experience ranging from first-year radiology residents to attending musculoskeletal radiologists. Sensitivity and specificity, and intraobserver variability of MRI interpretation of meniscal tears were calculated for each reviewer and compared to those of readers of the same and varying levels of MRI training and experience. Accuracy (range, 78% to 88%), sensitivity (range, 79% to 88%), and specificity (range, 72% to 94%) results were high, and intraobserver agreement was moderate to high (range, 0.49 to 0.77), in the diagnosis of meniscal tears for all reviewers with 4 or more years of radiology residency training and 3 months of formal MRI experience. In contrast, the accuracy (range, 63% to 82%), sensitivity (range, 58% to 79%), and specificity (range, 58% to 72%) results of reviewers with less experience and training were lower, with higher intraobserver variability. Our results suggest that experience and training play an important role in the accurate and reliable MRI diagnosis of meniscal tears.

Adolescent↗
PubMed1997

Arthropathies and inflammatory conditions of the elbow.

MR imaging of arthropathies and inflammatory conditions affecting the elbow are presented. Noninfectious conditions discussed include osteoarthritis, disorders characterized by synovial proliferation, pigmented villo- nodular synovitis, synovial osteochondromatosis, crystal deposition disorders, and neuropathic osteoarthropathy. Infectious conditions discussed include septic olecranon bursitis, septic arthritis, osteomyelitis, and pyomyositis. Clinical aspects of these entities are discussed, including utility of MR imaging for diagnosis and clinical management.

Arthritis↗
PubMed1995

Osteomyelitis in feet of diabetics: clinical accuracy, surgical utility, and cost-effectiveness of MR imaging.

PURPOSE: To evaluate sensitivity, specificity, clinical utility, and cost-effectiveness of magnetic resonance (MR) imaging in the diagnosis of osteomyelitis of the foot in diabetics. MATERIALS AND METHODS: MR studies of 62 feet (diabetics [n = 27], nondiabetics [n = 35]) in 59 patients were prospectively evaluated to detect the presence and extent of osteomyelitis. Biopsy (n = 41 feet) and clinical follow-up (n = 62 feet) were used to establish the diagnosis, select treatment, and determine outcome; sensitivity and specificity of MR imaging were calculated. A cost analysis was performed. RESULTS: Sensitivity and specificity of MR imaging in the diagnosis of osteomyelitis were 82% and 80%, respectively, in diabetics and 89% and 94%, respectively, in nondiabetics. There was no recurrent infection at the surgical margin in 13 feet in which the area of limited resection had been delineated at MR imaging. CONCLUSION: MR imaging shows good sensitivity and specificity for diagnosing osteomyelitis in diabetic feet, and it is competitively priced compared with other imaging modalities. Accurate delineation of extent allows limited surgical resection, making MR imaging clinically useful and cost-effective.

Case-Control Studies↗
PubMed1995

Immunoreactivity of canine epithelial and nonepithelial neoplasms with monoclonal antibody B72.3.

Monoclonal antibody (MAb) B72.3, which binds to a human tumor-associated glycoprotein termed TAG-72, was applied to a wide range of epithelial and nonepithelial neoplasms from dogs. Immunoreactivity was detected by the use of an avidin-biotin complex (ABC) immunoperoxidase method. A variety of epithelial neoplasms, but none of the nonepithelial neoplasms, were positive (> or = 5% staining) for MAb B72.3. MAb B72.3 stained 100% (4/4) of gastric, 100% (6/6) of intestinal, 50% (2/4) of pancreatic, and 80% (4/5) of rectal adenocarcinomas but only 20% (1/5) of squamous cell carcinomas and 20% (1/5) of complex tubular mammary gland adenocarcinomas. None of the hepatocellular carcinomas and perianal and sebaceous gland adenocarcinomas stained. Most types of benign epithelial neoplasms did not stain, except for 75% (6/8) of rectal adenomas and 25% (1/4) of squamous cell papillomas. Normal gastrointestinal mucosa adjacent to and entrapped in neoplasms did stain with MAb B72.3. None of the benign and malignant nonepithelial neoplasms of mesenchymal, neuroendocrine, or lymphohematopoietic tissue origin stained. The results of this study demonstrate that MAb B72.3 has selective immunoreactivity for adenocarcinomas, especially those arising from the digestive tract; however, limited immunoreactivity was observed for other types of carcinomas and benign epithelial neoplasms and for normal gastrointestinal mucosa in the dog.

Animals↗
PubMed1995

Immunoreactivity of canine transitional cell carcinoma of the urinary bladder with monoclonal antibodies to tumor-associated glycoprotein 72.

Tumor-associated glycoprotein 72 (TAG-72) is a large, high molecular weight, mucinlike antigen that is expressed in a wide variety of human carcinomas. Three different TAG-72 monoclonal antibodies (MAbs), designated B72.3, CC49, and CC83, were applied to the following archived samples from the dog: 1) 51 transitional cell carcinomas of the urinary bladder, 2) 15 hyperplastic/inflamed urinary bladders, and 3) eight normal urinary bladders. Immunoreactivity was detected with an avidin-biotin complex immunoperoxidase method. Fifty-three percent (27/51) of transitional cell carcinomas were positive (> or = 5% staining) for MAb B72.3. MAb B72.3 staining of these transitional cell carcinomas did not statistically correlate with any of the examined features of malignancy, including histologic grade, clinical stage, DNA ploidy, or presence of vascular/lymphatic invasion. In regard to the staining of transitional cell carcinoma by the other two TAG-72 antibodies, 53% (27/51) of the samples were positive for MAb CC83 and 63% (32/51) were positive for MAb CC49. The finding that similar populations of neoplastic urothelial cells in serial sections from the same neoplasm stained with all three TAG-72 antibodies supports the hypothesis that an antigen similar to TAG-72 was expressed in canine transitional cell carcinoma. None of the normal urinary bladders nor any of the hyperplastic/inflamed urinary bladders stained with any of the three TAG-72 antibodies tested. The results of these studies demonstrated that the staining of canine transitional cell carcinoma with all three TAG-72 antibodies was specific for neoplastic urothelial cells and that an antigen similar to TAG-72 was expressed.

Animals↗
PubMed1994

Giant cell variant of malignant fibrous histiocytoma in dogs: 10 cases (1986-1993).

Signalment, tumor sites, clinicopathologic, radiographic, and ultrasonographic features, as well as treatment protocols and survival information, were evaluated for 10 dogs with a histologic diagnosis of giant cell variant of malignant fibrous histiocytoma. Common clinical findings included subcutaneous masses, weight loss, anorexia, and lethargy. Laboratory abnormalities included anemia, hypoalbuminemia, and high concentrations of serum hepatic enzymes. Radiography and ultrasonography were useful in staging the extent of metastasis. Seven dogs had tumor metastasis at the time of diagnosis. Two other dogs developed evidence of metastasis during the course of treatment. The most common sites of tumor involvement were subcutaneous tissues, lymph nodes, liver, and lungs. Treatment protocols included surgical resection, intraoperative radiotherapy, and chemotherapy. Median survival time of all dogs was 61 days. Median survival time of the 6 treated dogs was 161 days. Findings on necropsy revealed metastasis with multiple organ involvement. The giant cell variant of malignant fibrous histiocytoma was determined to be a highly metastatic neoplasm in dogs, which may be responsive to surgical excision, chemotherapy, or radiotherapy.

Animals↗