SEARCH · PubMed Health

Results for “Visible Human Projects”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33Linked to original sources

PubMed1994

Rotational angiography assessment of cerebral aneurysms.

PURPOSE: To compare rotational angiography with conventional digital subtraction angiography in the assessment of cerebral aneurysms. METHODS: Conventional digital subtraction angiography and rotational angiography were compared in 57 patients investigated for the preoperative diagnosis of subarachnoid hemorrhage and in 13 patients after surgery. Images were compared for location, visibility of the aneurysmal neck, vascular branch anatomy, projection, size, presence of spasm, and shape of the aneurysm. RESULTS: Rotational angiography was superior to the digital angiogram in assessing aneurysms and vascular anatomy in the following percentage of cases: 12% for location, 46% for the presence of a neck, 32% in the assessment of branch anatomy, 19% for projection, 12% for size, 3.5% for spasm, and 19% for shape. After surgery, rotational angiography more clearly demonstrated the presence or absence of a neck in 69% of the cases. CONCLUSIONS: Rotational angiography often allows better visualization of vascular anatomy and therefore improves the angiographic assessment of aneurysms when compared with conventional digital subtraction angiography, making it an excellent adjunct in the investigation of subarachnoid hemorrhage. The lack of subtraction artifacts from the surgical clips and multiple angles of view also allow better assessment of the presence or absence of a residual neck in postoperative cases.

Angiography, Digital Subtraction↗

PubMedDate not supplied

The visible embryo project: embedded program objects for knowledge access, creation and management through the World Wide Web.

We have designed a prototype knowledge management online environment for the biomedical sciences which integrates access to online representations of the scientific literature, bibliographic databases, high-performance visualization technologies, large-scale scientific databases, and tools for authoring new-generation scientific publications. This system will provide widespread access to its resources by using the World Wide Web for its underlying architecture. This system expands upon our Weblet Interactive Remote Visualization (IRV) server technology to produce a set of dedicated Internet "visualization servers" which provide interactive control of real-time visualizations from the Visible Embryo Project database from within Web pages viewed with our WebRouser software package. This system will be used to develop a set of prototype applications for both online education of medical students in developmental anatomy and for an interactive patient education system for expectant parents. We recognize that knowledge represented by these national resource databases is not static, therefore it is essential to include tools for both the creation of new "compound documents" which incorporate embedded objects, as well as for managing the peer-review of scholarly publications, in order to ensure the integrity of new knowledge as it is added to these databases in the future. We have therefore begun to design integrated tools for our system which facilitate both the creation of and the validation of new generations of scientific knowledge.

Anatomy, Cross-Sectional↗

PubMed2004

Towards objective evaluation of the skin aspect: principles and instrumentation.

BACKGROUND/AIMS: The aim of this paper is to propose an objective procedure for the evaluation of the skin aspect. This work is based on light scattering phenomena and in-vivo measurements of the skin profile and of the skin Bi-directional Reflection Distribution Function (BRDF). METHODS: We consider the basic mechanisms of light reflection and scattering by a surface to extract the key sur-face-parameters of aspect. It appears that the surface relief is determinant for the local surface orientation while the light scattering properties of the skin are responsible for the visibility of that skin relief. The first part presents the principles of skin-image formation on the retina and de-scribes the actual roles of the BRDF and of the skin relief. The second part is dedicated to experimental measurements on the skin in vivo. The 3D relief is reconstructed by a fringe projection method and numerical processing. The angular distribution of light reflected by the skin is also measured by means of a different set-up. RESULTS: The knowledge of both the skin relief obtained by 3D optical profilometry and the skin scattering behavior measured for regularly distributed set angle values, allows an objective aspect evaluation as well as a prediction of the skin images that an observer will receive. CONCLUSION: This paper presents both the principles and instrumentation elements suitable for the setting up of an objective evaluation procedure of the skin aspect.

Dermoscopy↗

PubMed1997

Navigational aids for real-time virtual bronchoscopy.

OBJECTIVE: Virtual bronchoscopy is a recently described technique for performing simulated bronchoscopy using data obtained from thin-section CT scans of the airways. Although the detail visible during virtual bronchoscopy can be striking, the lack of global context and physical cues can lead to disorientation for the radiologist, especially during real-time "fly-throughs." We investigated the use of seven software tools (coordinate axes, global maps, trail markers, cross-references to standard two-dimensional projections, rear-view windows, collision avoidance, and stereoscopic displays) that are navigational aids to overcome such disorientation. CONCLUSION: The navigational aids performed satisfactorily on virtual bronchoscopy studies from 21 patients. A frame rate of one to seven frames per second, depending on the complexity of the bronchial model, could be attained. Several of the aids worked best when used selectively or when updated frequently but not continuously. Navigational aids are potentially useful for guiding radiologists who do virtual bronchoscopy studies. Such aids are general tools that may be applicable to other types of virtual endoscopy.

Adult↗

PubMed1992

[The role of CT in diagnosis and therapy of fractures of the pelvic girdle].

The conventional pelvic overview and special projections of the pelvic ring are often not conclusive for the diagnosis of pelvic ring fractures. The superimposition of multiple bony and soft tissue structures interfere with correct three-dimensional orientation of the bony lesions in spite of special projections. CT offers the possibility of identifying pelvic fractures that are not visible in conventional radiographs. Dislocated fractures can especially be appreciated. With CT, it was possible for the first time to classify lesions of the sacroiliac joint: (I) distortion (vacuum phenomena), (II) rupture of the ventral sacroiliac ligaments (open book), (III) lesions of the ventral and dorsal sacroiliac ligaments, and (IV) luxation of the os sacrum. Lesions of the sacrum can also be classified into four groups: (I) diastasis of the sacroiliac joint, (II) sacral lip fractures, (III) vertical fractures and compression fractures, (IV) comminuted fractures. Above all, the CT scan facilitates an accurate examination of the dorsal pelvic ring. Furthermore, better appreciation of intrapelvic soft tissue lesions is possible. In a retrospective study on 53 patients, in 88.7% we had quite helpful and extremely helpful CT examinations, and 90% higher precision in comparison to conventional radiographs.

Female↗

PubMed1993

A quantitative assessment of patient motion and its effect on myocardial perfusion SPECT images.

Patient motion during image acquisition is a frequent cause of SPECT perfusion image artifacts. We sought to determine the relationship between patient motion and the resultant image artifact. The effect of patient motion on 201Tl SPECT scintigrams was assessed with computer simulation to create 66 new image sets with artifactual vertical, horizontal and combined patient motion introduced over a broad range in six normal studies. Visual analysis of regional radioactivity in these simulated images, as well as quantitative analysis of the resultant polar coordinate display was performed. The presence and extent of "motion" artifacts varied with the number and location of the projection images affected, as well as the extent of their displacement. Although the extent of the defect varied with the frames affected, they were not necessarily more extensive when related to vertical displacement in the center of the orbit. The location of induced defects varied with direction of displacement and the location of frames affected. Vertical and horizontal motion created additive defects. Defect size grew with incremental vertical displacement but subsequently decreased with yet increasing displacement. Both the irregular, "lumpy" distribution of radioactivity, often with opposing "defects", as well as curvilinear extraventricular radioactivity, were visual clues suggesting SPECT defects related to motion artifact. A clinical case review revealed that approximately 25% of studies demonstrate such motion during acquisition but only 5% contribute to visible image deterioration. While detection is important, postacquisition attempts to correct such artifacts are incomplete and optimally, they must be prevented.

Artifacts↗

PubMed1996

The AGROBOT project.

The aim of this paper is to illustrate the AGROBOT project. This project was initiated to develop a complete robotic system for the production cycle of tomato plants in a greenhouse environment. The robot architecture is based on a vehicle carrying the picking arm (a six degrees of freedom anthropomorphic arm with a gripper/hand), the head with the two micro cameras (for the color stereoscopic vision system) and the VME rack for the complete control of the system. The head was purposely developed to permit complete visibility of the overall area. The vision system drives the head to point the path during navigation or to explore the plants looking for the work objects. The robot will be able to navigate between rows of plants, stop near each plant and identify the relevant objects (fruits or flowers) so as to be able to pick ripe tomatoes or spray anticryptogamic substances on flowers. Due to its flexible architecture, the system can be suited to operate on other kinds of cultivation or could be modified to perform other kinds of operations such as transplanting or packaging. Also the field of action could be different from greenhouses: changing from a wheeled locomotion system to a tracked system, the robot will be able to operate on particularly irregular surfaces. These features make this robotic system particularly adapted to replace human from tiring and harmful tasks or operating within adverse environment.

Agriculture↗

PubMed1991

Simultaneous immunohistochemical detection of IUdR and BrdU infused intravenously to cancer patients.

Cell cycle kinetics of solid tumors in the past have been restricted to an in vitro labeling index (LI) measurement. Two thymidine analogues, bromodeoxyuridine (BrdU) and iododeoxyuridine (IUdR), can be used to label S-phase cells in vivo because they can be detected in situ by use of monoclonal antibodies (MAb) against BrdU (Br-3) or IUdR (3D9). Patients with a variety of solid tumors (lymphoma, brain, colon cancers) received sequential intravenous IUdR and BrdU. Tumor tissue removed at the end of infusion was embedded in plastic and treated with MAb Br-3 and 3D9 sequentially, using a modification of a previously described method. Clearly single and double labeled cells were visible, which enabled us to determine the duration of S-phase (Ts) and the total cell cycle time (Tc), in addition to the LI in these tumors. Detailed control experiments using tissue culture cell lines as well as bone marrow cells from leukemic patients are described, including the comparison of this double label technique with our previously described BrdU-tritiated thymidine technique. We conclude that the two methods are comparable and that the IUdR/BrdU method permits rapid and reliable cell cycle measurements in solid tumors.

Antibodies, Monoclonal↗

PubMed1995

Duodenal adenomatosis in familial adenomatous polyposis. DAF Project Group.

In order to evaluate the prevalence of duodenal adenomas in familial adenomatous polyposis (FAP) and the risk of carcinoma development, a multicenter study was initiated in Denmark, Finland, Holland, Norway and Sweden, which have national polyposis registers with an almost complete registration. Patients aged 20 years or more are being examined with biennial gastroduodenoscopy during 1990-2000. Multiple duodenal biopsies are examined by one pathologist from each country, and the endoscopic and histological criteria of Spigelman have been adopted. At the end of August 1992, 312 patients with a median age of 37 years (range 20-86) had completed their first endoscopy. The duodenum was examined in 310 patients, of whom 199 (64%) had duodenal adenomas. Twenty-two patients (11% of all patients with duodenal adenomas) had no endoscopically visible polyps. One patient had an asymptomatic adenocarcinoma. The Spigelman stage worsened significantly (P < 0.05) with time from the diagnosis of FAP, which may suggest an increasing risk of carcinoma by time.

Adenomatous Polyposis Coli↗

PubMed1984

[Spontaneous rupture of the ascending aorta. Rare form of parietal ulceration on angiography, with pericardial effusion].

A localised rupture of the aorta, notably less frequent than a true dissection, is often difficult to diagnose and should be attentively sought for whenever faced with acute chest pains resulting from a suspected aortic lesion. The authors' observation show, on aortography, a small ulcer-like projection on the internal wall of the dilated ascending aorta, only visible on an antero-posterior view. The true scientific value of this image is arguable and we are reminded of the rigorous routine needed in any angiographical examination. The particular case in question involves a subadventitial ulcer which could be the initial stage of a true dissection. The echography demonstrated the presence of a pericardial effusion (whose dreaded prognostic value is well known), but no aortic lesion. The authors feel that the diagnostic reliability of echography, computed tomography and digital subtraction angiography warrants further systematic study. It would appear that direct aortography until otherwise proved, remains the only real method capable of detecting these localised ruptures at an early stage, before their spontaneous and dramatic evolution into perforation or a true dissection; and so benefiting the patient from surgical repair work only without prosthesis insertion.

Aged↗

PubMed1996

Diverticular bleeding and the pigmented protuberance (sentinel clot): clinical implications, histopathological correlation, and results of endoscopic intervention.

UNLABELLED: Over a 3-yr period, we performed colonoscopy on five patients (mean age 71 yr) in whom a specific diverticulum that contained a pigmented protuberance (PiP) was unequivocally identified as the cause for hemorrhage. Four of these individuals had endoscopic bipolar cauterization of the PiP, and two patients had surgery. AIM: To (1) determine the clinical significance of an intradiverticular PiP, (2) correlate endoscopic features of a PiP with histopathological findings and, (3) assess results of endoscopic treatment for affected patients with lower GI bleeding. METHODS: Medical charts were reviewed to garner data and assess outcome for patients. The bleeding diverticulum in one surgical case was detected in the resected specimen, and histological examination was performed. RESULTS: The mean number of transfusions, bleeding days, and lowest hemoglobin concentration before definitive treatment was 4.8, 3.4, and 8.4 gm%, respectively. All patients rebled before treatment. In all instances, the PiP projected through the neck of the diverticulum, which was actively bleeding in two patients. Endoscopic bipolar cautery directed at the PiP achieved permanent hemostasis in three of four subjects (75%) (morbidity 0%). Endoscopic therapy failed in one subject, and a hemicolectomy was performed. Histological evaluation of the resected specimen showed erosion of a medium sized artery into the diverticulum. The PiP represented a sentinel clot (not a visible vessel) adherent to a breach in the vessel wall. A patient who had surgery instead of endoscopic therapy had a prolonged, complicated postoperative course. CONCLUSIONS: (1) The presence of an intradiverticular PiP may identify a subset of patients at risk for severe recurrent diverticular bleeding. (2) Histopathological analysis showed the PiP to be a sentinel clot rather than a visible vessel. (3) In patients with severe recurrent diverticular bleeding, endoscopic treatment of the vessel beneath this lesion may be a viable alternative to surgery.

Aged↗

PubMed2003

Too small for a seatbelt: predictors of booster seat use by child passengers.

OBJECTIVES: Motor vehicle injury is the leading cause of injury death for children 4 to 8 years of age. Although booster seat use in this age group substantially reduces the risk of injury, most children are currently restrained by seatbelts designed for adults. The objective of this study was to measure booster seat use directly, determine factors predictive of proper child restraint, and assess parental reasons for booster use and nonuse. METHODS: We conducted a cross-sectional, observational study in Seattle, Washington, Spokane, Washington, and Portland, Oregon, from February to April 2000. Drivers were surveyed in their vehicles after picking up children from schools and child care centers. Trained observers recorded child age, weight, and height and directly observed restraint use. Observed restraint use was compared with the recommended restraint method based on the child's weight and age. Data were analyzed using multivariate logistic regression, adjusted for clustering by car and site. RESULTS: We observed 2880 children traveling in cars, 1539 of whom were eligible for booster seat use. Eighty-eight percent of drivers agreed to respond to our survey. Only 16.5% of children for whom a booster seat was recommended were properly restrained, compared with 80% of younger children for whom a child safety seat was recommended and 55% of children for whom an adult seatbelt was recommended. Relative to a 4-year-old booster-eligible child, a 6-year-old was only half as likely to use a booster seat (odds ratio [OR]: 0.47; 95% confidence interval [CI]: 0.31-0.71) and an 8-year-old almost never used a booster seat (OR: 0.04; 95% CI: 0.01-0.19). Booster use was more common when the driver wore a seatbelt (OR: 3.1; 95% CI: 1.8-5.4). Parents whose children were using booster seat cited "safety" (61%) and "child comfort and visibility" (12%) as their primary concerns. When a child was not using a booster seat, parents most often believed that their child was "too big for a car seat" (56%), reported that the seat was in another vehicle (9%), or stated that they "had not heard" of booster seats (8%). CONCLUSIONS: Many parents still incorrectly believe that children are safe in a seatbelt and have outgrown the need for a car seat. These results demonstrate the need for public education campaigns to educate parents about booster seat use.

Automobile Driving↗

PubMed1980

Visualization of right atrial appendix by thallium-201 myocardial scintigraphy: concise communication.

The atrial myocardium has been barely visible with thallium-201 myocardial scintigraphy. This is probably related to the difference in size, distance from anterior chest wall, and small coronary blood flow of the atrium, compared with the ventricle. We have encountered eight cases of visualization of the right atrial appendix (RAA). All had disease involving the right side of the heart, such as mitral stenosis (four cases), congenital heart disease (two), cor pulmonale (one), and primary myocardial disease (one). The RAA was identified from multiple projections in all cases and sometimes confirmed by radionuclide angiocardiography. The RAA was seen at the right upper aspect of the ventricles and was distinguishable from them. Evidence derived from ECG, chest radiographs, and cardiac catheterization, indicated that the most important factor in the visualization might be the displacement of the RAA to a more anterior position.

Adult↗

PubMed1993

[Diagnosis of colonic tumors and chronic inflammatory colonic diseases by hydrocolonic sonography].

Retrograde instillation of water into the colon makes it possible to visualize the colon sonographically from the rectosigmoid transition to the cecum in 97% of the patients examined. The sonographic views obtained using this technique, which is called hydrocolonic sonography, show the echo-free intestinal lumen, the five individual layers of the colon wall and the connective tissue surrounding the colon. Colonic polyps and carcinomas appear sonographically as echogenic structures projecting from the intestinal wall into the lumen. Colonic polyps larger than 7 mm diameter can be identified in 91% of cases, and the sensitivity of the technique in the detection of carcinomas of the colon is 97%. In addition, detailed evaluation of the structure of the bowel wall permits more precise staging of tumors of the colon. Aside from such localized changes, hydrocolonic sonography can also demonstrate typical changes in the wall structure in chronic inflammatory large-bowel diseases. In acute Crohn's disease the normal stratified appearance of the colonic wall is no longer in evidence and the wall appears visible thickened. In contrast, in patients with acute ulcerative colitis the normal sonographic stratified appearance of the colonic wall is maintained. Hydrocolonic sonography enables a detailed sonographic examination of the colonic lumen and the colon wall, thus providing additional information and allowing more precise diagnosis of many diseases of the colon.

Colonic Neoplasms↗

PubMed2003

Three-dimensional ultrasound imaging of the pelvic floor: the effect of parturition on paravaginal support structures.

OBJECTIVE: It is assumed that support of the female urethra and bladder is maintained by paraurethral and paravaginal fascial structures, with hypermobility resulting from delivery-related trauma. This study used three-dimensional translabial ultrasound to assess these structures and document peripartal changes. DESIGN: A clinical observational pilot study was performed on 26 nulliparous women recruited in the third trimester of pregnancy. They underwent translabial two- and three-dimensional ultrasound. Twenty-three women were again seen 2-5 months postpartum. The assessor was blinded against two-dimensional ultrasound and delivery data. Vaginal tenting was rated as being present, indeterminate or absent at each of three levels, and was correlated with bladder neck descent (BND) and urethral rotation on Valsalva maneuver. RESULTS: Tenting was visible at all levels in 21 of 26 women antepartally. In three women tenting was absent on one level; in two cases tenting was rated indeterminate. There was no significant difference in BND between women with visible tenting and those without. The BND range for women with intact tenting was 5.4-41.6 mm. Twenty-one of the 26 women were included in the postpartum analysis. Of these, obvious peripartal changes were documented in five. Loss of tenting did not correlate significantly with changes in BND. CONCLUSIONS: Most nulliparous women showed evidence of intact paravaginal support structures. Tenting occurred in women with widely varying BND, implying that excess bladder neck mobility may be due to increased fascial compliance. Postnatally, fascial disruption was suspected in a minority of patients only. In some women delivery-related changes may be due to attenuation rather than disruption of structures.

Adult↗

PubMed1997

Observer performance methodologies for evaluating blood vessel visibility in MR angiograms using accurate geometric registration to high resolution x-ray angiograms.

Receiver operator characteristic (ROC) and two alternative forced choice (2AFC) methodologies for quantitatively assessing vessel visibility in MR angiography (MRA) were examined using x-ray angiography images as truth. The methodologies required MRA projection images with the same orientation and magnification as the x-ray images. Geometric distortions limited the quality of the registration. The observer performance measurements were compared to vessel contrast-to-noise ratio (CNR) measurements. Receiver bandwidth (RBW) and magnetization transfer (MT) effects in 3D time-of-flight MRA were evaluated. Overall, applying MT significantly increased all three measurements while decreasing the RBW significantly improved the 2AFC and CNR measurements. The relative importance of both effects on the 2AFC measure increased as vessel diameter decreased, although statistical significance was limited by small samples for diameters less than approximately 0.7 mm. These results demonstrate the usefulness of these observer performance methodologies for MRA technique assessment.

Angiography, Digital Subtraction↗

PubMed2005

4 T MRI of chondrocalcinosis in combination with three-dimensional CT, radiography, and arthroscopy: a report of three cases.

OBJECTIVE: To describe 4 T MRI techniques in imaging chondrocalcinosis within the knee and examine the results together with those demonstrated using three-dimensional (3D) computed tomography, conventional radiography, and arthroscopy. DESIGN AND PATIENTS: From a larger clinical imaging study of early osteoarthritis, knee arthroscopy patients were imaged using high-field MRI and high-resolution 3D CT prior to their surgery. Retrospective review of the imaging data diagnosed three patients with chondrocalcinosis. Fat-suppressed 3D spoiled gradient (3D SPGR) and two-dimensional fat-suppressed fast spin echo (FSE) imaging was performed at 4 T. The MR images, multi-planar reformatted CT (MPR-CT) and maximum intensity projection CT (MIP-CT) images, and radiographs were examined by a musculoskeletal radiologist for the presence and location of chondrocalcinosis. The findings from arthroscopy were also included. RESULTS: MRI showed 16 sites of punctate hypointense regions from 18 articular surfaces and five of six menisci with similar signal characteristics. Both meniscal chondrocalcinosis and meniscal tears were clearly visible using the 3D SPGR sequence. Only three sites were demonstrated to have calcification using MPR-CT and MIP-CT revealed an additional three. In articular cartilage surfaces showing surface disruption, arthroscopy demonstrated 11 sites with crystal deposition. Arthroscopy also revealed five menisci with calcification present. CONCLUSION: Our preliminary findings suggest that imaging chondrocalcinosis using spoiled gradient 4 T MRI is superior and complementary to the other imaging modalities in the detection of crystal deposition in both articular cartilage and menisci.

Adult↗

PubMed2004

Reconstruction of anterior nasal septum: back-to-back autogenous ear cartilage graft.

OBJECTIVES/HYPOTHESIS: The ideal material for reconstructing the nasal septum in the deficient nose has not been found. Since 1986, the authors have used autogenous cartilage from the cavum conchae to successfully correct the anterior septum and the associated cartilaginous saddle. The long-term results in 26 patients with a destroyed septum and a saddle nose are reported. STUDY DESIGN: Retrospective study. METHODS: The mean age of the patients at surgery was 40.2 years, and the mean number of previous nasal procedures was 1.6. Because 11 patients had septal perforations and insufficient septal cartilage or bone, ear cartilage grafts from the cavum conchae were harvested through an anterolateral approach. A special incision was used to divide the concave ear cartilage while preserving the posterior perichondrium. This produced a stable, balanced back-to-back graft. The graft was 2.5 to 3 cm long, long enough to allow reconstruction of the anterior septum and to correct part of the saddle nose deformity. The rest of the conchal cartilage was used to fill the remaining cartilaginous saddle. Follow-up investigations included photographs and visual analogue scales of the patients' symptoms and satisfaction. RESULTS: After a mean interval of 36.7 +/- 22.3 months, the back-to-back grafts showed no macroscopic signs of resorption. Graft position and shape remained intact after transplantation. All noses were adequately projected and mobile. All patients but one were satisfied with the functional and esthetic result. With a score of 4 representing the level of satisfaction as "very good," the mean score of the patients was 3.2 +/- 0.79. The saddle of the nose completely disappeared in 65.4% of patients, was minimally visible in 23.1%, and was slightly present in 11.5%. Nasal breathing improved considerably in 21 patients, remained the same in 4 patients, and worsened in 1 patient. The mean score of all patients for nasal breathing was 7.3 +/- 1.87 on a visual analogue scale of 0 to 10, with 10 representing satisfaction as "very good". CONCLUSION: The back-to-back autogenous ear cartilage graft is a viable, stable, and balanced graft for functional and aesthetic reconstruction of the anterior nasal septum and cartilaginous saddle deformity in patients with a severely traumatized and deficient septum.

Adolescent↗