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Biomedical subjects

F Hooper

Publications and source records attributed to F Hooper.

15 recordsLinked to original sources
PubMed2000

Liver and bone window settings for soft-copy interpretation of chest and abdominal CT.

OBJECTIVE: We evaluated whether the use of multiple window and level settings on a soft-copy workstation improves diagnostic accuracy on chest and abdominal CT. We hypothesized that routinely using window and level settings during soft-copy interpretation would beneficially affect the final diagnosis without compromising efficiency. MATERIALS AND METHODS: Two hundred three randomly selected abdominal and chest CT scans were interpreted by three radiologists using a four-monitor soft-copy workstation (images per screen, nine; resolution, 2K). After the initial interpretations, all scans were reevaluated by the same radiologists using additional liver and bone window and level settings. Differences in conspicuity and characterization of abnormalities were graded on a three-point scale. RESULTS: Conspicuity and characterization of abnormalities were improved in 67% of abnormal findings (81/121; p = 0.01). Improvement (a finding that substantially affected the final diagnosis) was present in 18% of abnormal findings (22/121; p = 0.04). On average, the evaluation of images at multiple window and level settings required an additional 40 sec per case. CONCLUSION: The use of multiple window and level settings during soft-copy interpretation resulted in improved lesion detectability and characterization with greater diagnostic efficacy. Using soft-copy workstations, radiologists can evaluate images using multiple settings without compromising efficiency.

Bone Diseases↗
PubMed1999

Impact of filmless radiology on frequency of clinician consultations with radiologists.

OBJECTIVE: The purpose of the study was to determine the impact of filmless operation on the relative frequency of in-person consultations in the radiology department between radiologists and clinicians. CONCLUSION: The transition to filmless operation at the Baltimore Veterans Affairs Medical Center was associated with an 82% reduction in the in-person consultation rate for general radiography and a 44% reduction for cross-sectional imaging despite an increase in the volume of studies. The major reason for this decrease was the convenient access to current and prior images provided by the PACS (picture archiving and communication system). Radiology departments contemplating a transition to filmless operation should prepare for communication with clinicians to shift from being mostly in person to being conducted more and more through electronic forms of communication.

Baltimore↗
PubMed1998

Impact of filmless imaging on the frequency of clinician review of radiology images.

The purpose of this study was to determine the impact of filmless imaging on the frequency with which physicians access radiology images and to assess clinician perception of image accessibility using a hospital-wide Picture Archival and Communication System (PACS). Quantitative data were collected at the Baltimore VA Medical Center (BVAMC), prior to and after conversion to filmless imaging, to determine the frequency with which clinicians access radiology images. Survey data were also collected to assess physician preferences of image accessibility, time management, and overall patient care when comparing filmless and film-based modes of operation. In general, there was a significant increase in the average number of radiology images reviewed by clinicians throughout the hospital. However, the one are in the hospital where this trend was not observed was in the intensive care unit (ICU), where the frequency of image assess was similar between film and filmless operations. Ninety-eight percent of clinicians surveyed reported improved accessibility of images in a filmless environment resulting in improved time management. The mean clinician estimate of time saved due to the use of PACS was 44 minutes. The study documented a combination of clinician perception of improved accessibility and substantial time savings with the use of a hospital-wide PACS, which was supported by objective measurements. The increased frequency of image review by clinicians and rapid image access should provide a further impetus to radiologists to decrease report turnaround time to provided "added value" for patient care.

Baltimore↗
PubMed1997

The impact of routine CT of the chest on the diagnosis and management of newly diagnosed squamous cell carcinoma of the head and neck.

OBJECTIVE: The purpose of the study was to ascertain how often additional malignant neoplasms are detected on CT scans of the thorax in patients with newly diagnosed squamous cell carcinoma of the head and neck and to determine how often these findings are evident on conventional radiographs of the chest. SUBJECTS AND METHODS: One hundred eighty-nine patients with newly diagnosed squamous cell carcinoma of the head and neck were prospectively examined in a 5-year period. At the time of the initial diagnosis, each patient underwent both chest radiography (posteroanterior and lateral radiographs in 95%, anteroposterior in 5%) and thoracic CT to assess the prevalence of additional primary or metastatic malignant neoplasms of the thorax and upper abdomen. RESULTS: Of the 189 patients studied, 66 showed a total of 73 significant abnormalities on thoracic CT scans of which only 17 abnormalities (23%) were detected on chest radiographs alone. Of these 66 patients, 36 (55%) were found to have one or more primary or metastatic neoplasms. These 36 patients manifested a total of 41 additional primary or secondary malignant neoplasms including 24 cases in which one or more pulmonary nodules were detected, six cases of lymphadenopathy, three hepatic lesions, three bone lesions, two pleural masses, two esophageal masses and one adrenal mass. Of these 41 malignant tumors, 13 (32%) were synchronous primary tumors and 28 were metastases. Only 12 (29%) of the 41 malignant tumors detected by thoracic CT were seen on the chest radiographs. In all patients in which an additional malignant tumor was diagnosed, clinical management was significantly affected, resulting in a modification of the planned surgery or the addition of chemotherapy, radiation therapy, or both. CONCLUSION: A relatively large percentage of patients (19%) with newly diagnosed squamous cell cancer of the head and neck was found to have additional malignant tumors, 32% of which were synchronous primary tumors. The discovery of these additional neoplasms had a major effect on both the therapy and the prognosis of these patients. The combination of a relatively poor detection rate for conventional chest radiography, with only 29% of the malignant tumors detected on CT scans of the chest being seen on chest radiographs, and the high prevalence of disease in this population support the routine inclusion of thoracic CT in these patients.

Carcinoma, Squamous Cell↗
PubMed1996

Picture archiving and communication systems and vascular surgery: clinical impressions and suggestions for improvement.

The purpose of this study was to determine the acceptance and clinical utility of a large scale picture archiving and communication system (PACS) for vascular surgery. Questionnaires and one-on-one interviews were conducted with physicians and nurses in the department of vascular surgery at the Baltimore VA Medical Center where PACS has been in routine, hospital-wide use for more than 2 1/2 years. The perceptions of the clinical staff were assessed to determine the efficacy of PACS in comparison to the conventional film based alternative for the practice of vascular surgery and suggestions for improvements were solicited. There was consensus among the vascular surgery staff members that the use of PACS enhanced their clinical practices, both in and out of the operating room (OR). Vascular surgeons heavily rely on image display in the OR as a "road map" to help determine their operative approach and to guide their surgery. PACS offers unique intraoperative imaging capabilities including rapid image retrieval and improved archival, cine review, the ability to modify image contrast, and the ability to obtain direct quantitative measurements of the degree of vascular stenosis. The increased accessibility and availability of images throughout the hospital enables improvement in time management and in patient care.

Baltimore↗
PubMed1996

Ascertaining dementia by expert panel in epidemiologic studies of nursing home residents.

A new method for ascertaining dementia in epidemiologic research and the results of a study to evaluate it are described. The method relies on an expert panel of clinicians reviewing clinically relevant information collected by lay evaluators to arrive at a diagnosis based on DSM-III-R criteria. The approach was developed to study dementia in a statewide sample of over 2400 new admissions to 59 nursing homes in Maryland. Expert panel ascertainment of dementia was compared to that obtained by direct clinical evaluation for 100 nursing home residents. Agreement between the panel and direct assessment was 76% (kappa = 0.59) using a three-category classification of dementia, no dementia, and indeterminate. This ascertainment strategy provides an alternative to methods currently in use and is particularly well-suited for populations with a high prevalence, in those dispersed over large geographic areas, and when timely, cost-effective evaluations are required.

Aged↗
PubMed1996

Role of the CD6 glycoprotein in antigen-specific and autoreactive responses of cloned human T lymphocytes.

CD6 is a 130 000 MW T-cell surface glycoprotein that can deliver coactivating signals to mature T lymphocytes. Studies using monoclonal antibodies (mAb) have defined at least four epitopes on CD6, and distinct functional responses are elicited by mAb to the different epitopes. The function of CD6 is unknown. Multiple CD6 ligands are predicted, based on data that a soluble CD6 fusion protein precipitates at least three peptides. A cDNA clone for one of these ligands, termed activated leucocyte-cell adhesion molecule (ALCAM) has recently been isolated. In order to further characterize the role of CD6 in cell-cell interactions, we have examined the role of CD6 in a variety of responses by tetanus toxoid (TT) specific human T-cell clones. Anti-CD6 mAb UMCD6 (epitope 3) inhibits antigen-specific responses of such clones to TT, but not to the superantigen SEA. Responses of clones to nominal antigen are CD6-dependent using either peripheral blood mononuclear cells (PBMC) or macrophage-depleted E rosette negative cells as the antigen-presenting cell (APC) population. Furthermore, these clones made autoreactive with DNA methyltransferase inhibitors express increased CD6, and autoreactivity is inhibited by UMCD6. Taken together, the data suggests the existence of a functional CD6 ligand in peripheral blood which is expressed by APC, including cells other than macrophages. Interactions between CD6 and CD6 ligands may regulate both antigen specific and autoreactive responses of human T lymphocytes.

Antigen-Presenting Cells↗
PubMed1995

Efficacy and safety of a rapid-sequence metaproterenol protocol in the treatment of acute adult asthma.

A 6-month prospective study was performed to examine the efficacy and safety of a rapid-sequence nebulized metaproterenol regimen for the treatment of acute asthma in adults. Patients 18 years of age or older who were not pregnant and who had not received beta 2-agonist therapy were identified and started on a rapid-sequence metaproterenol regimen (15 mg) by the triage nurse. Pretreatment and posttreatment peak flow, respiratory rate, pulse rate, and blood pressure were documented. Patients also gave a pretreatment and posttreatment rating of the clinical severity of their attack using a 1-to-10 visual analogue scale. Fifty patients were entered into the study, with an average age of 38 years (range, 19 to 87 years). Data were analyzed using the Wilcoxon matched-pairs signed rank test. Patients showed statistically significant increases in peak flow (193 to 328 L/min, P < .00001) and systolic blood pressure (136 to 143 mm Hg, P < .0054). Statistically significant decreases were shown for respiratory rate (25 to 22 beats/min, P < .0001) and clinical severity (6.2 to 3.2, P < .00001). Thirty-three patients (71%) who completed the protocol experienced an increase in pulse rate. Ten (21%) had a pulse rate increase of more than 30 beats/min. Two (4.2%) had pulse rate increases of more than 40 beats/min. Four patients were removed after one or two nebulizers because of severe side effects. One patient's pulse rate increased to more than 200 beats/min. Although effective in reversing bronchospasm, the side effects of metaproterenol when used in rapid sequence are of major concern.

Adult↗
PubMed1994

Lymphocyte function-associated antigen 1 overexpression and T cell autoreactivity.

OBJECTIVE: To determine if DNA methylation inhibitors make T cells autoreactive by inducing lymphocyte function-associated antigen type 1 (LFA-1) (CD11a/CD18) overexpression. METHODS: T cell clones were treated with 3 distinct DNA methylation inhibitors or were stably transfected with a CD18 cDNA in a mammalian expression vector, and the effects on LFA-1 expression and activation requirements were examined. RESULTS: LFA-1 overexpression, caused by DNA methylation inhibitors or by transfection, correlates with the development of autoreactivity. CONCLUSION: LFA-1 overexpression may contribute to T cell autoreactivity.

Azacitidine↗
PubMed1993

The efficacy and safety of a continuous albuterol protocol for the treatment of acute adult asthma attacks.

We performed a prospective study over a 6-month period to test the efficacy and safety of a continuous nebulized albuterol protocol for the treatment of acute adult asthma attacks. All patients 18 years or older presenting to the emergency department with acute asthma attacks were begun by the triage nurse on the protocol of three continuous albuterol (2.5 mg) nebulizer treatments. Pretreatment and posttreatment peak flow, respiratory rate, pulse, and blood pressure were documented and patients gave a pretreatment and posttreatment rating of the clinical severity of their attack using a (1 to 10) visual analog scale. In addition, all adverse effects were noted. Seventy-six patients were entered in the study. The average age was 44 years (range, 20 to 82 years). Pretreatment and posttreatment peak flow, respiratory rate, pulse, blood pressure, and clinical severity were compared using the paired t test. Patients showed statistically significant increases in peak flow (128 to 292; P < .0001) and statistically significant decreases in respiratory rate (27 to 20; P < .0001); pulse, 103 to 94 (P < .0001); clinical severity, 7.8/10 to 1.8/10 (P < .0001); and blood pressure, 141/82 to 132/77 (P < .001). Adverse effects were minimal. Two patients (2.6%) felt flushed, three patients (4%) felt jittery, and one patient (1.3%) had a sensation of palpitations. We conclude that a continuous nebulized albuterol protocol is both extremely efficacious and safe for the treatment of acute adult asthma attacks.

Acute Disease↗