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At least 613 records · Page 34Linked to original sources

PubMed2005

News media coverage of a women's health contraversy: how newspapers and TV outlets covered a recent debate over screening mammography.

Over the past decade, there have been several highly visible debates about mammography that have captured professional, public and media attention. This paper looks at newspaper and television news coverage of a controversial research letter in The Lancet by Gøtzsche and Olsen (2001) that concluded that screening mammography did not prevent deaths from breast cancer. The news pieces examined for this project were published between October 2001 and March 2002 in one of eight U.S. newspapers or aired on one of six national or cable news networks. The six-month period was divided into one-week segments; the numbers of articles published or stories aired in each week were graphed to examine patterns. Each newspaper article and television transcript was then reviewed to identify its main content area and the amount of coverage for each major event was quantified. The highest number of newspaper articles appeared to result from several events during the end of January through the beginning of February. These events included the publication of another meta-analysis of mammography that disputed the original letter's conclusion and a full-page New York Times advertisement paid for by major medical organizations stating their continued support for mammography. The greatest amount of television news coverage was devoted to the announcement of the official federal guidelines by the Secretary of Health and Human Services in late February. We conclude by discussing how the flow of news coverage of medical controversies can potentially impact the actions and reactions of the public, the medical community and health policy makers.

Bibliometrics↗

PubMed1999

Therapeutic benefits of infrared (810-nm) diode laser macular grid photocoagulation in prophylactic treatment of nonexudative age-related macular degeneration: two-year results of a randomized pilot study.

OBJECTIVE: This pilot study collected preliminary information on the effectiveness and safety of infrared (810-nm) diode laser macular grid photocoagulation in patients with nonexudative age-related macular degeneration (AMD). Results from this pilot study were used in designing a larger, multicenter, randomized clinical trial. DESIGN: A multicenter, randomized, controlled, clinical trial. PARTICIPANTS: A total of 229 eyes of 152 patients with AMD were enrolled in the pilot study. Seventy-five patients with 1 eye eligible (75 eyes) were enrolled in the unilateral arm of the study; 77 patients with both eyes eligible (154 eyes) were enrolled in the bilateral arm of the study. In the unilateral study arm, 32 eyes were randomized to the observation group, 27 eyes were treated with visible endpoint burns, and 16 eyes were treated with invisible endpoint (subthreshold) lesions. In the bilateral study arm, 77 eyes were in the observation group, 36 eyes were treated with visible burns, and 41 eyes were treated with subthreshold (invisible) lesions. INTERVENTION: Eyes were treated with infrared (810-nm) diode laser macular grid photocoagulation using either visible burns or subthreshold (invisible) lesions and compared to eyes receiving no treatment. MAIN OUTCOME MEASURES: Reduction of drusen, change in visual acuity, and rate of choroidal neovascularization (CNV) membrane formation. RESULTS: At 12 months after treatment, 62% of eyes treated with visible burns had a clinically significant reduction in drusen, whereas this proportion (65%) was reached in 18 months for eyes treated with subthreshold lesions. At 24 months' follow-up, treated eyes had a significant reduction in drusen compared to observation eyes (P < 0.0001). Visual acuity was significantly improved in treated eyes at 12, 18, and 24 months compared to observation eyes (P < 0.001). Choroidal neovascularization formation was similar in treated and observation eyes through 24 months' follow-up. Complications included CNV associated with six eyes treated with visible burns and a juxtafoveal laser scar in one eye treated with visible burns. CONCLUSIONS: Infrared (810-nm) diode laser macular grid photocoagulation in patients with nonexudative AMD significantly reduces drusen levels (P < 0.0001) and significantly improves visual acuity (P < 0.001) when either visible endpoint burns or subthreshold endpoint lesions are used. Complications were fewer using subthreshold endpoint lesions. A larger, multicenter, prospective clinical trial with longer follow-up is needed to determine the efficacy of treatment in reducing the rate of CNV formation. Data from this clinical pilot study have been used to design the Prophylactic Treatment of AMD Trial (PTAMD), a multicenter, randomized, prospective clinical trial currently in progress comparing subthreshold (invisible) treatment to observation in eyes with nonexudative AMD.

Aged↗

PubMed2000

MRI of the inner ear: comparison of axial T2-weighted, three-dimensional turbo spin-echo images, maximum-intensity projections, and volume rendering.

RATIONALE AND OBJECTIVES: To compare the ability of axial T2-weighted, three-dimensional, turbo spin-echo (3D TSE) images, targeted maximum-intensity projections (MIPs), and 3D volume reconstructions to depict anatomic details of the labyrinth. METHODS: In 24 volunteers, 3D TSE images were obtained. MIPs and 3D volume reconstructions were performed from the acquired data. All images were evaluated by three radiologists independently regarding the visualization of the different anatomic structures. RESULTS: In the axial slices, most anatomic details were visible in comparison with observations by the other modalities. The 2.5 windings of the cochlea were best depicted on the MIPs. Volume reconstructions rendered excellent spatial information regarding the vestibule and semicircular canals and were the only technique that demonstrated all three ampullae in all cases. CONCLUSIONS: Axial TSE images, MIPs, and 3D volume reconstructions are complementary modalities that provide different information. Our results suggest that improved diagnostic information can be obtained by applying these volume visualization reconstruction techniques.

Adult↗

PubMed1983

Computerized multiplanar imaging and lumen area plotting for noninvasive diagnosis of carotid artery disease.

Some of the errors associated with pulsed Doppler imaging of the carotid bifurcation relate to the fact that the vessels are usually viewed in only one plane. To reduce these projection errors, a computerized ultrasonic arteriograph (CUA) was developed, which simultaneously produces lateral and anteroposterior images of the carotid bifurcation together with a histogram that depicts the cross-sectional area of the lumen at 1 mm points along the vessel. The area measured from the histogram and that estimated from biplanar arteriograms agreed in 46/57 (81%) of the internal carotid arteries studied by both techniques. The area histogram was positive for 91% of the arteries with arteriographically visible disease and was 79% specific for eliminating the presence of disease. The combined CUA study (histogram plus images) had a sensitivity and specificity of 96% and 80% for detecting any disease, 96% and 92% for evaluating diameter stenoses of 20%, and 89% and 98% or evaluating stenoses of 40%. These preliminary results suggest that the CUA may enhance the accuracy of pulsed Doppler imaging.

Carotid Artery Diseases↗

PubMedDate not supplied

Three-dimensional imaging and reconstruction of skin lesions.

An optical instrument called a "nevoscope" is used to image skin lesions by transillumination with visible light. The lesion is transilluminated by a fiber-optic annular ring light source that directs light into the skin area surrounding the lesion, forming a virtual source just beneath the lesion. Mirrors uniformly spaced around the lesion and tilted at various angles provide orthographic projections of the skin lesion. Additional views are obtained by rotating the mirror assembly. These multiple views are used in a direct three-dimensional (3D) reconstruction of the lesion using a filtered backprojection method. In this paper, we discuss the methodology of direct 3D reconstruction from 2D views of a transilluminated skin lesion as obtained using the new prototype nevoscope. We present the results of direct 3D reconstruction of a simulated phantom and a test object imaged using the nevoscope. In addition, a skin lesion was scanned in situ using the new prototype nevoscope. Results of the reconstruction of this lesion are also presented.

Algorithms↗

PubMedDate not supplied

Gated cardiac imaging of the aortic valve on 64-slice multidetector row computed tomography: preliminary observations.

PURPOSE: To conduct a pilot study to determine the feasibility of evaluating aortic valve morphology and motion on electrocardiogram-gated 64-slice cardiac MDCT. METHODS: Four-dimensional images of the aortic valve were reviewed in 20 consecutive patients who underwent computed tomography (CT) coronary angiography. A consensus reading of 3 readers was performed of valve visibility, number of leaflets, valve motion, and calcification. Visibility of the valve leaflets and visualization of opening and closing of the valve leaflets were graded as well seen or suboptimally seen. The number of valve leaflets (3 or 2) and presence of valvular calcification were noted. RESULTS: The aortic valve was well seen in all 20 patients. Three leaflets were identified in all cases, and no calcifications were seen. Valve movement with opening and closure of the leaflets during the cardiac cycle was also well seen in all cases. CONCLUSIONS: Visualization of the aortic valve and valvular motion during the cardiac cycle is feasible on CT studies performed for coronary angiography. CT has a potential role in the assessment of aortic valvular pathology.

Aortic Valve↗

PubMedDate not supplied

The layering phenomenon and boundary formation in radiographs.

In a radiographic examination using a water-soluble contrast medium this may form a layer beneath a body fluid. Between the two liquids a zone consisting of a mixture of the two liquids then forms through diffusion. This diffusion layer produces some characteristic features in the radiographic image, an analysis of which was the purpose of the model experiments performed in this investigation. In this analysis of the layering phenomenon the radiographed objects were cylindrical tubes of methyl methacrylate partly filled with water. In some cases a rod was placed concentrically in the tube. Contrast medium was layered below the water. Radiographs were produced with the tube either vertical or inclined, and with either a horizontal or a vertical projection. In the image the layer of contrast medium was visualized as a light field, and the water layer as an overlying relatively dark field. The diffusion layer was visualized as a transitional zone--the diffusion field. Distinct boundaries and Mach lines observed in the bottom field were produced by the interface between the contrast medium and the solid wall where it was touched by the roentgen rays. These boundaries continued into the diffusion field where they gradually became less visible and eventually disappeared. The upper and lower boundaries of the diffusion field were diffuse and associated with dark and light Mach bands, respectively. The upper boundary appeared to be convex upwards. In the case of the inclined model and a vertical beam the diffusion field was elliptical, with a still more diffuse transition to the fields above and below than in the case of the vertical model and a horizontal beam.(ABSTRACT TRUNCATED AT 250 WORDS)

Body Fluids↗

PubMedDate not supplied

[Posterior shoulder luxations (author's transl)].

In one out of two cases, posterior shoulder luxation is a diagnostic, clinical, and radiological "trap", which we feel has no true justification. In fact, contrary to what is generally admitted, a good analysis of the frontal image can easily suggest the diagnosis in most cases. All that is required is knowledge of the two principal indirect signs of posterior luxation. Increase in size of the glenohumeral interline is almost constantly present (12 out of 14 cases), and the "compression-fracture" of the anterior face of the head is often visible (9 out of 14 cases). Furthermore, if a strictly frontal film of the glenohumeral interline is requested in all cases of shoulder injury, the diagnosis of luxation is evident as the head is projected into the glenoid cavity. Profile films must also be taken. When the luxation is of recent origin, axillary profile films are usually impossible to take, and trans-thoracic profile films of the upper end of the humerus are taken, even though these do not show the glenohumeral interline. For this reason, it is essential to request an immediate Bloom and Obatas' profile. This incidence confirms the presence of posterior luxation and enables the anterior face of the head and the posterior glenoid rim to be studied. The diagnostic value of the two principal indirect signs of posterior luxation, as seen in frontal films and Bloom and Obatas' glenohumeral profile, is undeniable. The joint prognosis depends, in fact, on how early treatment is applied.

Adult↗

PubMed2002

[CT angiography of the coronary arteries with a 16-row spiral tomograph. Effect of spatial resolution on image quality].

PURPOSE: To evaluate image quality of coronary CT angiography with retrospectively ECG-gated 16 multi-slice spiral CT (MSCT), reconstructed with 0.75 mm slice thickness for optimal spatial resolution and with 1.3 mm slice thickness, to produce spatial resolution comparable to a 4-MSCT. MATERIALS AND METHODS: Ten patients underwent coronary CT angiography with a 16-MSCT (Siemens Sensation 16, Forchheim, Germany) with 0.75 mm detector collimation. Raw helical CT data were retrospectively reconstructed using two different settings. Setting A: B20f smooth kernel, axial MPR with 1.3 mm slice thickness and 0.7 mm increment. Setting B: B35f "HeartView" medium-smooth kernel, 0.75 mm slice thickness, 0.5 mm increment. In the axial slices two regions of interest (ROIs) were placed in the area of the aortic root (AR) and more caudal in the area of the left ventricle (LV). Image noise was determined by the standard deviation of the CT numbers.Two readers determined visibility of coronary arteries by standardized maximum intensity projections (MIP) post-processing in left, right anterior and left anterior oblique projection plane from setting A and B. Each projection was rated on a five point rating scale concerning plaque delineation. Points determined for each data set were summed up and used for comparison. RESULTS: No significant difference between the CT-numbers was found for setting A and B (A: 283.0 in AR/295.9 in LV and B: 282,9 in AR/297.2 in LV; p >0.2). However, the image noise was significantly different for setting A and B (A: 4.46 in AR/1.67 in LV and B: 8.16 in AR/7.38 in LV; p <0.01). Better delineation of the coronary arteries and atherosclerotic lesions could be achieved from MIP projections in setting B compared to setting A. CONCLUSION: Higher image noise is present in coronary 16-MSCT with thin-slice reconstruction compared to simulated 4-MSCT. However the MIP-reconstructions benefit most from the higher spatial resolution.

Coronary Angiography↗

PubMed1996

Peripapillary fluorescein angiographic findings in primary open angle glaucoma.

BACKGROUND: Detailed fluorescein angiographic findings in the disc circumference may be useful for evaluating the possible relation of the circumference to glaucomatous nerve damage. METHODS: Fluorescein angiograms of 25 eyes of 25 subjects with primary open angle glaucoma were observed after they had undertaken Octopus perimetry. Based on the retinotopic projection, disc sectors and corresponding visual field regions were set. RESULTS: Twenty three eyes (92%) showed a zone of no fluorescence around the disc (non-fluorescent zone). Of these, the zone width of the 20 eyes that had visible ciliary vessels within the zone was wider than that of the other three eyes, and showed fluorescein diffusion from the outer boundary of the zone towards the disc. The diffusion reached the disc if the zone was narrow. In those 20 eyes, a standardised difference in the zone width of inferior temporal sector minus superior temporal sector correlated with the difference in mean loss of corresponding visual field regions (r = 0.48, p = 0.0312). CONCLUSION: The visible ciliary vessels suggest the absence of the choriocapillaris in the non-fluorescent zone, the width of which correlated with the visual field defect and may affect the amount of the fluorescein diffusion to the disc. This suggests that the diffusion might be related to optic nerve damage in glaucoma.

Female↗

PubMed1990

The lateral transverse thigh free flap: an alternative for autogenous-tissue breast reconstruction.

The lateral transverse thigh free flap is a horizontal variant of the more commonly known vertical tensor fasciae latae myocutaneous free flap. Fresh cadaver injections of the lateral circumflex femoral artery indicated simultaneous perfusion of the upper lateral thigh tissues and the standard tensor fasciae latae territory extending down the lateral thigh. These experimental data strongly indicated that the clinical application would be successful. The flap is composed mostly of fat from the prominence of the upper lateral thigh ("saddlebags") based on a small plug of underlying tensor fasciae latae muscle. The amount of skin that can be included with this flap is limited in a vertical dimension to about 6 to 8 cm but is determined by the ability to close the defect. We have performed 17 flaps in 11 patients with up to 18 months of follow-up. Ten were delayed and 7 were immediate reconstructions. The chest and hip dissections are performed simultaneously by two microsurgeons. There has been one flap loss due to arterial disruption on day 3. An early problem was seroma formation in the donor site, which has been improved in the later patients by closing the dead space with sutures. The lateral transverse thigh free flap has the following advantages over other methods of autogenous-tissue breast reconstruction: (1) longer, more peripherally placed vessels, (2) easier flap dissection and no need to turn the patient during the procedure, (3) decreased postoperative morbidity and more rapid recovery, (4) reduction of an area of excess fat in those patients in whom the hips are more prominent than the abdomen, (5) greater intrinsic internal projection of the flap, and (6) excellent vascularity. The disadvantages of the flap are (1) microsurgery is required, (2) the amount of skin available is not as great as that with the gluteal or transverse rectus abdominis musculocutaneous (TRAM) flap, (3) the scar on the upper lateral thigh is probably more visible than on the buttock or the abdomen, and (4) a balancing procedure on the opposite hip is usually necessary in unilateral cases. Our current indications for the lateral transverse thigh free flap are (1) the transverse rectus abdominis musculocutaneous flap is unavailable, (2) for a particular breast size, the thigh fat proportions are greater than the abdominal proportions, or (3) the patient prefers this option to the transverse rectus abdominis musculocutaneous or gluteus flap. Results and complications with the lateral transverse thigh free flap will be presented along with pertinent comparisons with the other choices for autogenous-tissue breast reconstruction.

Adult↗

PubMedDate not supplied

A multicenter clinical evaluation of the treatment of mild to moderate inflammatory acne vulgaris of the face with visible blue light in comparison to topical 1% clindamycin antibiotic solution.

BACKGROUND: Blue light sources have been shown to be effective in the treatment of mild to moderate inflammatory acne vulgaris lesions. OBJECTIVE: We evaluated the safety and efficacy of a new blue light source in the treatment of mild to moderate inflammatory acne vulgaris in comparison to topical 1% clindamycin solution. RESULTS: Blue light therapy reduced inflammatory acne vulgaris lesions by an average of 34%, as compared to 14% for topical 1% clindamycin solution. CONCLUSIONS: The blue light source presented in this report is a safe and effective treatment option available to our patients with mild to moderate inflammatory acne lesions.

Acne Vulgaris↗

PubMed1997

The effect of high-efficiency particulate air respirator design on occupational health: a pilot study balancing risks in the real world.

OBJECTIVES: To quantify specific factors believed to increase healthcare worker (HCW) risk for contaminated sharps injuries (eg, visibility, communication, and range of motion); to quantify the degree to which respirators of various designs impacted those same factors; and to assess HCW opinions about the suitability of selected respirators with respect to patient care and user compliance criteria. DESIGN: Sharps injury data from seven hospitals were analyzed to determine the potential contribution of visibility, communication, and range of motion to reported injuries. Healthcare workers representing various clinical specialties and physical characteristics were examined at baseline and while wearing five different respirators to quantify the impact of respirator design on visibility, communication, and range of motion. Healthcare workers were interviewed and completed a survey assessing each respirator. SETTING: Hospital and ambulatory-care settings. PARTICIPANTS: Population-based and convenience sample. RESULTS: Communication, visibility, and range of motion were found to affect contaminated sharps injuries significantly. Selected high-efficiency particulate air (HEPA) respirators were found to have a negative impact on each of these variables. Healthcare workers involved in the study also reported compliance criteria problems with selected HEPA respirators, which may effect implementation of respiratory precautions adversely. CONCLUSION: Current HEPA respirators, because of their design, potentially increase the risk of bloodborne pathogen exposure through sharps injuries. We conclude that mandating respirators without regard to the potential impact of their design to the sharps injuries may be counterproductive to HCW safety, because they may increase, rather than decrease, overall occupational risk to HCWs.

Air Pollution, Indoor↗

PubMed1996

Local immunocompetence and salivary cortisol in confinement.

The present study describes the effects of a 60-day isolation period on the salivary levels of cortisol and secretory IgA. The study took place in the context of the EXEMSI project in which four volunteers were isolated in a space station-like chamber in the DLR Institute of Aerospace Medicine in order to examine the effects of long term isolation. Inspection of the individual immunoglobulin A secretion rates revealed different patterns of cyclic variation with respect to the weekday-weekend schedule, and different time lags for the adaptation leading to a plateau for this parameter. The salivary cortisol levels showed a circadian rhythm with high concentrations in the early morning (7:30 am) and lower concentrations in the late evening (11:00 pm). Moreover, in all subjects marked increases of salivary cortisol were observed in a 12- to 14-day cycle. In two subjects the marked morning-evening differences were only visible at the weekends. The salivary cortisol and immunoglobulin A levels were determined twice weekly before and after completion of a complex decision-making test. The results reveal a changed responsiveness in all subjects at different times.

Adult↗

PubMed2000

MR angiography of the intracranial venous system.

PURPOSE: To compare the effectiveness of different imaging planes at time-of-flight (TOF) magnetic resonance (MR) angiography and phase-contrast MR angiography in the visualization of the normal intracranial venous system. MATERIALS AND METHODS: In 12 healthy volunteers, two-dimensional (2D) TOF MR angiography and three-dimensional (3D) phase-contrast MR angiography were performed in transverse, sagittal, and coronal planes. All data were displayed as maximum intensity projection (MIP) images. Four neuroradiologists assessed the visibility of 28 intracranial venous structures on the MIP images. Statistical analysis was performed by using the Friedman two-way analysis of variance and the Cochran Q test. RESULTS: Visualization of the normal intracranial venous system was better with 3D phase-contrast and coronal 2D TOF MR angiography than with transverse or sagittal 2D TOF MR angiography (P < .05, Friedman test) for each observer and the group of observers. Differences were found between each of the 2D TOF and 3D phase-contrast MR angiographic sequences in the visualization of individual venous structures (Cochran Q test). The kappa values ranged from 0.36 to 0.71, which indicated a moderate to good agreement between observers. CONCLUSION: The normal intracranial venous system is adequately visualized with 3D phase-contrast and coronal 2D TOF MR angiography.

Adult↗

PubMed1998

Fluoroscopic MR of the pharynx in patients with obstructive sleep apnea.

PURPOSE: The purpose of our study was to introduce an ultrafast MR imaging technique of the pharynx as a diagnostic tool for viewing the mechanism of obstruction in patients with obstructive sleep apnea. METHODS: Six healthy volunteers and 16 patients with obstructive sleep apnea were examined on a 1.5-T whole-body imager using a circular polarized head coil. Ultrafast two-dimensional fast low-angle shot sequences were obtained in midsagittal and axial projections during transnasal shallow respiration at rest, during simulation of snoring, and during performance of the Müller maneuver. All patients underwent physical examination, transnasal fiberoptic endoscopy, and polysomnography. RESULTS: Five to six images were obtained per second with an in-plane resolution of 2.67 x 1.8 mm and 2.68 x 2.34 mm, allowing visualization of motion of the tongue, soft palate, uvula, and posterior pharyngeal surface. MR findings correlated well with results of clinical examination. The length of obstruction in the oropharynx, which cannot be ascertained by transnasal endoscopy of the pharynx, was clearly visible MR images. Differences between patients with obstructive sleep apnea and healthy subjects in terms of the degree of obstruction in the velopharynx and oropharynx depicted on MR images during the Müller maneuver were highly significant. CONCLUSION: We believe that ultrafast MR imaging is a reliable noninvasive method for use in the evaluation of obstructive sleep apnea.

Airway Obstruction↗

PubMed1984

Microfocal radiographic examination of erosions in the wrist and hand of patients with rheumatoid arthritis.

The microfocal x-ray unit, a new type of x-ray machine characterised by an extremely small x-ray source, enables great detail to be recorded in the projection radiographs owing to the high object magnification and resolution obtained with this system. Microfocal radiographic examinations were carried out on the wrists and hands of 26 patients with early or moderately advanced rheumatoid arthritis. The macroradiographs confirmed the presence or absence of erosions in patients with early disease activity who otherwise had no detectable lesions visible in standard radiographs. The site of onset, development, and distribution of erosions are described. Their approximate order of appearance is listed. The first to appear occurred in the medial carpal bones, second and third metacarpophalangeal joints and third and fourth proximal interphalangeal joints. In origin they were subperiosteal either immediately adjacent to the insertion of an interosseous ligament or at the transitional zone of the articular cartilage. Erosions in the subchondral bone appeared subsequently and were either indirect (subperiosteal) or direct (subchondral) in origin. Cyst formation was frequently associated with the enlargement of an erosion which it often replaced.

Adolescent↗

PubMed1984

Characteristics of breast cancer in an incident cancer population.

The effectiveness of film mammography is a source of concern to radiologists because neither the ribs nor retromammary space is included on the films in good quality examinations. One hundred seven incident cancers were detected in 10,034 self-referred women followed at the University of Michigan Breast Cancer Detection Demonstration Project (UM-BCDDP) for 5 years. These cancers were analyzed for location on the film, method of detection, size, histology, and the number of films required for detection. Mammography alone detected 52 (49%) of the cancers, whereas physical examination alone detected 15 (14%). The other 40 cancers were detectable on both examinations. All of the 92 cancers detected by mammography were visible in both the mediolateral and the craniocaudal views. Only 2.2% of these cancers were within 1 cm of the posterior edge of the film in the mediolateral view; 18.7% were within 1 cm of the posterior edge in the craniocaudal view. These incident cancers were smaller, and fewer were located within the posterior 1 cm of the breast than in a similar study using the UM-BCDDP prevalent cancer population. Mammography consistently detected cancer in the breast, regardless of tumor size, histologic type, or location within the breast.

Adult↗