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Biomedical subjects

J D Collins

Publications and source records attributed to J D Collins.

At least 19 recordsLinked to original sources
PubMed1995

Compromising abnormalities of the brachial plexus as displayed by magnetic resonance imaging.

Magnetic resonance images (MRI) of brachial plexus anatomy bilaterally, not possible by plain radiographs or CT, were presented to the Vascular Surgery, Neurology, and the Neurosurgery departments. Patients were requested for MRI of their brachial plexus. They were referred for imaging and the imaging results were presented to the faculty and housestaff. Our technique was accepted and adopted to begin referrals for MRI evaluation of brachial plexopathy. Over 175 patients have been studied. Eighty-five patients were imaged with the 1.5 Tesla magnet (Signa; General Electric Medical Systems, Milwaukee, WI) 3-D reconstruction MRI. Coronal, transverse (axial), oblique transverse, and sagittal plane T1-weighted and selected T2-weighted pulse sequences were obtained at 4-5 mm slice thickness, 40-45 full field of view, and a 512 x 256 size matrix. Saline water bags were used to enhance the signal between the neck and the thorax. Sites of brachial plexus compromise were demonstrated. Our technique with 3-D reconstruction increased the definition of brachial plexus pathology. The increased anatomical definition enabled the vascular surgeons and neurosurgeons to improve patient care. Brachial plexus in vivo anatomy as displayed by MRI, magnetic resonance angiography (MRA), and 3-D reconstruction offered an opportunity to augment the teaching of clinical anatomy to medical students and health professionals. Selected case presentations (bodybuilder, anomalous muscle, fractured clavicle, thyroid goiter, silicone breast implant rupture, and cervical rib) demonstrated compromise of the brachial plexus displayed by MRI. The MRI and 3-D reconstruction techniques, demonstrating the bilateral landmark anatomy, increased the definition of the clinical anatomy and resulted in greater knowledge of patient care management.

Adult↗
PubMed1995

The anatomy of the brachial plexus as displayed by magnetic resonance imaging: technique and application.

Full field of view coronal chest magnetic resonance imaging (MRI) routinely displays bilateral images of the brachial plexus, surface anatomy, and anatomic structures. Eighty patients had chest radiographs correlated with surgery for thoracic outlet syndrome. The PA chest film findings correlated with the surgical findings: smaller thoracic inlet on the concave side of the cervicothoracic spine scoliosis, shorter distance between the dorsal spine of the second or third thoracic vertebral body to the concavity of the first ribs, asymmetric clavicles and coracoid processes, synchondrosis of the first and second ribs, and muscle atrophy on the side of the clinical complaints. More than 235 patients were imaged. One hundred sixty-five of these were imaged with a 1.5-T unit and 3-D reconstruction MRI. Coronal, transverse (axial), oblique transverse, and sagittal plane T1-weighted, selected T2-weighted, and fast spine echo pulse sequences were obtained, 4- to 5-mm slice thickness, 40 to 45 cm full field of view, 512 x 256 matrix and 2 NEX. Two-dimensional time of flight (2D TOF), magnetic resonance angiography (MRA) sequences were obtained in selected patients. Coronal, transverse, and sagittal sequences were reformatted for evaluation. Saline water bags were placed between the neck and thorax to enhance the signal-to-noise ratio. Compromising abnormalities of the brachial plexus were confirmed at surgery. Compromise of the neurovascular supply seemed to be one etiology that could be demonstrated. The clinical history, technique, and anatomic bilateral brachial plexus imaging is stressed to improve patient care. The cervical rib is one of the compromising brachial plexopathies selected for this presentation.

Adult↗
PubMed1994

The tuberculin test.

Tuberculin tests in general use today rely on the response to intradermal injections of tuberculin with assessment of the injection site for swelling at 72 hours post injection. Estimates of the sensitivity of tuberculin tests range from 68-95% while specificity is estimated to be 96-99%. The sensitivity of the test is affected by the potency and dose of tuberculin administered, the interval post-infection, desensitisation, deliberate interference, post-partum immunosuppression and observer variation. Specificity is influenced by sensitisation as a result of exposure to M. avium, M. paratuberculosis and environmental mycobacteria and by skin tuberculosis.

Animals↗
PubMed1993

Imaging the hepatic lymphatics: experimental studies in swine.

Magnetic resonance (MR) imaging augmented with 3-D MR reconstruction provides an excellent display of the soft tissues and surface anatomy of the human body. The excellent anatomical detail of MR images makes this radiographic modality an ideal tool to teach anatomy to all health-care professionals. Previous studies of the lung and liver in swine revealed that the hepatic lymphatics communicated with the visceral pleural lymphatics via the so-called pulmonary ligament, which appears as a sheet of visceral pleura containing lymphatics and small blood vessels in the swine model. A review of the surgical operative reports at the UCLA School of Medicine revealed that the hepatic lymphatics are not connected or even ligated during hepatic resections and transplantations. Therefore, the authors hypothesized that the unattached lymphatics may be a cause of postoperative complications and that interruption of these important lymphatic pathways may specifically result in immediate ascites and right pleural effusions. Cannulation of the hepatic lymphatics is proposed as a method to reduce postoperative complications. The purpose of this research is to demonstrate the visual and radiographic display of the hepatic lymphatics in a swine model and to provide a means to teach anatomical-pathological correlation.

Animals↗
PubMed1992

Can general surgeons perform colonoscopy safely?

The purpose of the current study was to review the safety of colonoscopy performed by nonfellowship-trained general surgeons. To address this issue, we reviewed more than 1,000 consecutive diagnostic and therapeutic colonoscopies and recorded the complications. This was a multi-institutional study involving seven general surgeons, none of whom had had formal fellowship endoscopic training. Perforation was confirmed by laparotomy, bleeding was defined as that requiring hospitalization and/or transfusion, and cardiopulmonary arrest was self-explanatory. There was one perforation in the diagnostic group and none in the therapeutic group, for a rate of 0.10% overall and 0.12% in diagnostic colonoscopy. There were no instances of bleeding or cardiac arrest. This complication rate of 1 per 1,025 colonoscopic procedures by general surgeons compares favorably with that previously reported by other specialties (p less than 0.001). We conclude that postgraduate endoscopy fellowship is not necessary for general surgeons to become safe colonoscopists.

Clinical Competence↗
PubMed1992

Fluoroscopic chest tube insertion and patient care.

Catheters and chest tubes may be placed under fluoroscopic control to reduce pleural effusions. This procedure has been adopted as a routine procedure at the UCLA School of Medicine in Los Angeles, California to improve patient care. This technique was modified for the placement of large chest tubes, which can be placed by a radiologist without multiple attempts or complications. Our experience with 2234 patients who underwent this procedure between 1977 and 1990 is described.

Catheterization↗
PubMed1991

Mediastinal masses: magnetic resonance imaging in comparison with computed tomography.

Seventy-eight patients with mediastinal abnormalities were imaged with magnetic resonance imaging (MRI) to evaluate mediastinal masses and associated lung, pleural, or chest wall disease. Magnetic resonance images were compared with computed tomography (CT) scans, which were available in 45 patients. While MRI and CT were equally effective in demonstrating mediastinal lesions, CT was superior for displaying calcification within a mass in eight patients and for demonstrating associated lung abnormality in four patients. Computed tomography should remain the imaging procedure of choice after chest radiography to evaluate mediastinal masses, although MRI may be indicated in selected patients.

Adolescent↗
PubMed1991

Magnetic resonance imaging of chest wall lesions.

Magnetic resonance imaging (MRI) demonstrates surface anatomy, nerves, and soft tissue pathology. Selective placement of the cursor lines in MRI displays specific anatomy. The MR images can then be used as adjunct in teaching surface anatomy to medical students and to other health professionals. Because the normal surface anatomy could be imaged at UCLA's radiology department, it was decided to image soft tissue abnormalities with MR to assist in patient care. Patients imaged were scheduled for special procedures of the chest or staging lymphangiograms. Patients were placed into categories depending on known diagnosis or interesting clinical presentation. The diagnostic categories included Hodgkin's disease, melanoma, carcinomas (eg, lung or breast), lymphedema, sarcomas, dermatological disorders, and neurological disorders. All images were orchestrated by the radiologist. This article discusses both the teaching and clinical impact on patient care.

Adult↗
PubMed1991

Anatomy of the thorax and shoulder girdle displayed by magnetic resonance imaging.

In 1971, radiographic anatomy of the human body was added to the gross anatomy course at UCLA. Radiographic contrast studies and plain anatomical displays were formulated into teaching packages for all organ systems. Residents presented each package to first-year medical students in the dissection laboratory to augment the teaching of anatomy. In November 1984, magnetic resonance imaging was instituted in the radiology department. Imaging the chest produced coronal and axial planes which displayed the muscles and soft tissues of the thorax. In 1986, the authors presented their study of MR anatomy of the chest and shoulder girdle to the American Association of Anatomists. The purpose of this presentation is to demonstrate the anatomy of the thorax and shoulder girdle as displayed by magnetic resonance, correlated with regional anatomy, with emphasis on soft tissue structures.

Humans↗
PubMed1990

Factors responsible for the introduction and spread of Campylobacter jejuni infection in commercial poultry production.

Campylobacter jejuni and related thermophilic campylobacters were not found in a hatchery or in chicks aged less than seven days. However, an increasing proportion of chicks aged two weeks and older shed campylobacters in their droppings. It was shown that a likely source of C jejuni for young chicks was the environment in the immediate vicinity of the rearing houses, and that infection could readily be introduced on the footwear and clothing of farm staff. Thermophilic campylobacters were found in the air, litter and drinking water containers in the rearing and finishing houses.

Air Microbiology↗
PubMed1990

Low prevalence of antibody to hepatitis C virus in north east England.

The prevalence of antibodies to hepatitis C virus (anti-HCV) was studied in North East England in blood donors, local multiply transfused patients, local high risk individuals, and chronic liver disease patients. Anti-HCV was detected by enzyme-linked immunosorbent assay (ELISA) in 2/1120 (0.18%) blood donors; 1/84 chronic renal failure patients on haemodialysis who had received 1,992 units of blood (seroconversion rate of 0.05% per unit transfused), 1/207 cardiac patients 6 months post cardiac surgery transfused with 1,403 units of blood (1 anti-HCV pre-operatively, seroconversion rate 0.07%), 40/50 haemophilia A patients treated with commercial factor VIII, and 38/100 intravenous drug users. In addition anti-HCV was detected by ELISA in 5/35 cryptogenic chronic liver disease patients, 5/5 confirmed by recombinant immunoblot assay (RIBA) (14%); 3/30 patients with autoimmune chronic active hepatitis, 2/3 by RIBA (7%); 2/50 primary biliary cirrhosis patients, 1/2 by RIBA (2%); 0/30 alcoholic cirrhosis patients; and 2/9 patients with hepatocellular carcinoma, 1/2 by RIBA (11%). HCV is uncommon in North East England; it may be implicated in the aetiology of a minority of cases of cryptogenic liver disease and less than 5% of autoimmune chronic active hepatitis and primary biliary cirrhosis.

Factor VIII↗
PubMed1990

Enhancing magnetic resonance images using water bags.

Fascial planes between tissues are separated by connective tissue, fat, and blood vessels. Magnetic resonance imaging displays surface anatomy and soft tissues. Our team has been successful in demonstrating brachial plexus nerves as a model of magnetic resonance anatomy. Radiologists have devised methods to increase the resolution of images by suppressing noise and increasing the sharpness of the image. We added water bags to a 0.3 tesla permanent magnet suppressing the noise and increasing the signal to image our patients. The images proved to be sharper.

Humans↗
PubMed1990

Lung biopsies and patient care at university-affiliated hospitals: a 20-year experience.

Lung biopsies have been performed since 1967 at the University of California at Los Angeles and its affiliated institutions. In the span of 20 years, the author performed 4285 cases and developed several procedures. This article discusses the importance of risk management and patient care and presents statistics on malignancies, complications, and contraindications.

Biopsy↗
PubMed1989

Mediastinal germ cell tumor in a young woman.

Primary mediastinal germ cell malignancies are uncommon neoplasms, usually presenting in young men. We review a case of a primary mediastinal seminoma occurring in a 23-year-old woman. The differential diagnosis, work-up and therapy for these lesions is discussed with emphasis on the role of magnetic resonance imaging in the evaluation of anterior mediastinal masses.

Adult↗
PubMed1989

Why is high resolution computerized tomography scanning used in evaluating the lungs?

High resolution computerized tomography scans have been used for medical and legal purposes to evaluate patients with a history of exposure to asbestos. Some investigators argue that high resolution scanning provides a better image of the lungs than routine computerized tomography. A review of the literature shows that although high resolution scanning displays the lymphatics in the lung, it offers no new useful diagnostic information. The authors conclude that no real advantage is attained with high resolution scanning of the lung and that pathology of disease can be determined decisively only by histology.

Evaluation Studies as Topic↗
PubMed1989

Nerves on magnetic resonance imaging.

Nerves are often visualized on magnetic resonance imaging (MRI) studies of the soft tissues on the chest and shoulder girdle. To learn the reasons for the contrast between the nerves and adjacent tissues, the authors obtained a fresh specimen containing part of the brachial plexus nerves from the left axilla and compared MRI with x-ray projections and photomicrographs of histologic sections. The results suggest that the high signals from the nerves stand out in contrast to the low signals from their rich vascular supply.

Connective Tissue↗
PubMed1989

Anatomy of the abdomen, back, and pelvis as displayed by magnetic resonance imaging: Part One.

In April 1986, magnetic resonance imaging (MRI) of the thorax and shoulder girdle was presented to the 99th Annual Meeting of the American Association of Anatomists. These images were the authors' first attempt to correlate the magnetic resonance display of the muscles and soft tissues of the chest in the coronal plane with surface gross anatomy. The original purpose of this study was to introduce the role of magnetic resonance imaging to anatomists, medical students, and the specialty of radiology. However, this approach has been expanded by imaging other sections of the body and applying the display of surface anatomy to augment the teaching of anatomy to surgical oncology, pathology, and kinesiology. This three-part article will display magnetic resonance images and will explain how magnetic imaging of the soft tissues can visually augment the teaching of gross anatomy without dissecting surface tissues.

Abdomen↗