PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Soft Computing”

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 1,297 records · Page 72Linked to original sources
PubMed1990

Assessment of broadband ultrasound attenuation in the os calcis in vitro.

1. We have examined the relationship between the attenuation of broadband ultrasound in the os calcis in vitro and its bone mineral density measured by quantitative computed tomography and by physical density. 2. Broadband ultrasound attenuation was found to correlate closely with physical density (r = 0.85, P less than 0.0001), but the correlation was less than that observed between quantitative computed tomography and physical density (r = 0.92, P less than 0.0001). Measurements of broadband ultrasound attenuation and quantitative computed tomography were significantly correlated (r = 0.80, P less than 0.0001). 3. Partial correlation analysis showed a significant relationship between broadband ultrasound attenuation and bone density, but when the effect of physical density was taken into account no significant correlation was found between broadband ultrasound attenuation and quantitative computed tomography (r = 0.08, not significant). 4. Broadband ultrasound attenuation in three prospective amputees showed a high degree of concordance between measurements in vivo and in vitro, with no interference by surrounding soft tissues. 5. The correlation between physical density and broadband ultrasound attenuation was independent of quantitative computed tomography, suggesting that the technique measures aspects of density which differ from its mineral density. Broadband ultrasound attenuation holds promise as a reproducible, rapid, radiation-free assessment of skeletal status.

Aged↗
PubMed2005

Diffusion and viscosity of a calamitic liquid crystal model studied by computer simulation.

We report a molecular dynamics simulation study on an ensemble of rod-like particles, each composed of nine soft spheres held rigidly along a line. We have calculated translational mean square displacements and velocity autocorrelation functions in the fluid phases exhibited by the model, i.e., smectic A, nematic and isotropic. These quantities have then been used to compute diffusion coefficients. In addition, we have calculated viscosities in the nematic and isotropic phases. Despite its crude nature, the model is capable of providing a faithful reproduction of many features of the transport behavior observed in real liquid-crystalline materials. The simulation results have been compared with the predictions of the modified affine transformation theory, finding only a fair agreement.

Journal Article↗
PubMed1983

Mycosis fungoides: manifestations on computed tomography.

Mycosis fungoides is a malignant lymphoma of the skin that causes intense erythema, plaques, edema, and induration. The primary computed tomographic findings of mycosis fungoides, i.e., skin thickening, tumorous infiltration, edema of the soft tissues, and lymphadenopathy, are presented in two patients.

Edema↗
PubMed2006

Alveolar soft-part sarcoma of the retroperitoneum.

A 33-year-old woman was referred to Iida Municipal Hospital because of left back pain. Computed tomography showed a tumor (17 x 11 x 10 cm) in the left retroperitoneal space. T1- and T2-weighted magnetic resonance imaging showed an inhomogeneous mass with marginal blood vessels. The tumor was resected via lumbar oblique incision with the thoraco-abdominal approach. The tumor weighed 1800 g and consisted of nests of 5-100 large, loosely arranged, polygonal cells, surrounded by capillaries, resembling alveoli. The tumor cells were rich in cytoplasm, containing periodic acid-Schiff- and diastase-positive granules and typical crystals. The pathological diagnosis was alveolar soft-part sarcoma (ASPS). Alveolar soft-part sarcoma is a rare soft-tissue tumor that accounts for approximately 0.5-1% of soft-tissue sarcomas. Such tumors originating in the retroperitoneal space are extremely rare. Herein is reported a case of ASPS of the retroperitoneum with radiological and pathological findings.

Adult↗
PubMedDate not supplied

Unsuspected and unrelated pathology noted on limited computed tomographic scans of the paranasal sinuses and temporal bone.

Modern imaging includes many studies performed to examine limited fields of view (i.e., paranasal sinus studies). These studies are frequently retrospectively coned to the limited field of view and are often examined only at one window and level setting. However, classic radiology teaching demands that all irradiated structures be examined by a qualified physician; for examples, on an intravenous pyelogram the examiner should look at not only the kidneys, ureters, and bladder, but also the bones, soft tissues, and gas patterns. This article illustrates unsuspected intracranial pathology noted on computed tomographic examinations of the paranasal sinuses and temporal bones.

Adult↗
PubMed1985

Magnetic resonance imaging in a patient with soft tissue sarcoma of the leg.

A patient with a high grade malignant fibrous histiocytoma of the leg is presented. Staging studies included a 99mTc diphosphonate bone scan, an arteriogram, a computed tomogram (CT) and a proton (1H) magnetic resonance imaging (MRI) study. By manipulating imaging parameters to enhance contrast between normal and neoplastic tissues, the latter technique more accurately delineated the extent of the soft tissue sarcoma than the other imaging modalities. Although spatial resolution of MRI is inferior to that of CT, it is likely that MRI will provide important information relative to surgical staging and preoperative planning that is not available from current imaging techniques.

Female↗
PubMed1994

Magnetic resonance imaging of the lacrimal drainage system.

BACKGROUND: Magnetic resonance imaging (MRI) has excellent spatial and soft tissue resolution in the periocular and orbital region, especially when combined with surface coil techniques. Other methods, including computed tomography, dacryocystography, and dacryoscintigraphy provide limited information in the area of the lacrimal drainage system. Magnetic resonance imaging was used in conjunction with other imaging modalities to compare the anatomic detail and clinically relevant information obtained about various pathologic processes in the lacrimal drainage area. METHODS: Patients with a variety of lacrimal drainage disorders underwent MRI with either head or surface coils. Contrast agents also were used in selected cases. Seven case reports are presented. RESULTS: Magnetic resonance imaging provided detailed information about local anatomy, extent of pathology, and, in some cases, etiology of the pathology. CONCLUSIONS: Magnetic resonance imaging with surface coils provides detailed soft tissue information when compared with dacryocystography and computed tomography in the area of the lacrimal drainage system. In selected cases of lacrimal drainage system pathology, MRI may provide data that affect patient management.

Abscess↗
PubMedDate not supplied

Fat signal suppression in head and neck imaging using fast spin-echo-IDEAL technique.

We present our initial experience with the use of a modified 3-point Dixon technique to obtain reliable fast spin-echo T1- and T2-weighted fat-suppressed images in the soft-tissue neck. The method has less sensitivity to magnetic field inhomogeneity than frequency-selective radiofrequency fat saturation and provides uniform fat suppression even near tissue-tissue and air-tissue interfaces. Clinical advantages and limitations of the method are discussed and several examples are shown.

Head and Neck Neoplasms↗
PubMed1983

Primary amyloid tumor of the lacrimal gland: CT findings.

We present a rare case of primary amyloid tumor originating in the lacrimal gland. The computed tomographic findings are similar to those of an orbital angioma, showing an enhancing soft tissue mass with multiple calcifications simulating phleboliths.

Amyloidosis↗
PubMed2004

Malignant transformation of an ovarian mature cystic teratoma: computed tomography findings.

INTRODUCTION: The malignant transformation of an ovarian mature cystic teratoma is rare. We presented such a case of a 46-year-old woman with characteristic computed tomography (CT) findings. CASE REPORT: The patient had suffered from fullness and tenderness of the lower abdomen for one year. A high serum CA-125 level was noted. Computed tomography images showed a left adnexal mass with fat, calcification and soft tissue components, and areas of invasion through the teratoma wall. OUTCOME: The histologic diagnosis was compatible with a squamous cell carcinoma arising from a mature cystic teratoma of the ovary.

Adipose Tissue↗
PubMed1989

Optimal specificity of thallium-201 SPECT through recognition of imaging artifacts.

Artifacts are produced in 201TI cardiac single photon emission computed tomography (SPECT) imaging because of a variety of causes including soft-tissue attenuation, overlying abdominal viscera, variable myocardial thickness, left bundle branch block, cardiac rotation, patient motion, and technical errors. Careful attention to quality control, utilization of motion detectors, and familiarization with potential artifacts will improve the specificity and diagnostic accuracy of 201TI SPECT for coronary artery disease.

Abdomen↗
PubMed1982

[CT diagnosis of the carotid cavernous fistula and differential diagnosis (author's transl)].

One of the many urgent cases requiring immediate attention is the possibility of continuous bleeding into the sphenoidal sinus via a carotid cavernous fistula (CCF). Computed tomography offers a necessary and quick diagnostic method for such soft-tissue structures. Difficulty in CT diagnosis is enhanced by the limitations inherent in certain diagnoses. The article shows that safe diagnosis can be achieved in acute postoperative CCF with great shunt volumes. When diagnosing spontaneous cases we must consider the clinical data to differentiate CCF from other causes.

Arteriovenous Fistula↗
PubMed1977

The diagnosis of diastematomyelia by computed tomography.

CT scanning has proven efficacy for the demonstration of normal and altered anatomy of the soft tissues of the head, providing information not available with any other modality. The introduction of total body CT has enabled us to study the entire spine and its contents. This new modality is extremely useful in diagnosing a variety of abnormalities of the spine, including diastematomyelia. A case is presented and the application of CT scanning to the spine is discussed.

Adult↗
PubMed1998

A new approach to Pneumatosis cystoides intestinalis by target air-enema CT.

A 48-yr-old man was admitted to our hospital with abdominal discomfort and distension. A barium enema showed multiple radiolucent filling defects in the wall of the ascending colon. Colonic endoscopy revealed numerous round, polypoid masses covered with normal mucosa. These findings suggested Pneumatosis cystoides intestinalis. Target air-enema computed tomography was performed to make a final diagnosis, and demonstrated several gas collections covered with soft tissue in the wall of the ascending colon. This is the first reported case of Pneumatosis cystoides intestinalis in which multiple gas-filled cysts could be recognized by target air-enema computed tomography.

Abdominal Pain↗
PubMedDate not supplied

Optical data acquisition for computer-assisted design of facial prostheses.

PURPOSE: The conventional impression technique for manufacturing facial prostheses has the disadvantage of deforming the soft tissues because of the tension caused by the impression material, as well as causing discomfort to the patient. The purpose of this study was to establish a system that allows contact-free reproduction of the facial surface combined with computer-assisted design and fabrication of facial prostheses. MATERIALS AND METHODS: Three-dimensional data of the facial surface were obtained using an optical acquisition system based on the method of phase-measuring profilometry. A sensor head with a fringe projector and two CCD cameras for photogrammetric triangulation were used in connection with a PC for measurement control and data evaluation. Software for computer-assisted design of the facial surface to be reconstructed was developed. A prototype facial prosthesis was fabricated using stereolithography. The system was tested using a modified puppet head. First clinical tests were performed with a patient who had undergone maxillofacial surgery including the resection of one eye. RESULTS: Three-dimensional data acquisition and imaging allow visualization of a whole face without causing tension or neuromuscular reaction. As surface brightness is also part of the digital model, it is even more realistic than a plaster cast. The stereolithographic object showed good marginal fit and satisfactory shape. CONCLUSION: The presented technique allows three-dimensional data reproduction of the facial surface, computer-assisted design of a facial prosthesis, and transfer to a rapid prototyping unit. The system has obvious advantages over conventional impression techniques. Further clinical trials are planned to evaluate the clinical success of the technique.

Computer-Aided Design↗
PubMed1998

Upper airway imaging.

Upper airway imaging is a powerful technique to study the mechanisms underlying the pathogenesis, biomechanics, and efficacy of treatment options in patients with obstructive sleep apnea. Imaging studies have provided significant insight into the static and dynamic structure, and function of the upper airway and surrounding soft-tissue structure during wakefulness and sleep. Upper airway imaging modalities primarily include nasopharyngoscopy, cephalometrics, computed tomography (CT), and magnetic resonance (MR) scanning. These imaging modalities have been used to study the effect of respiration, weight loss, dental appliances, and upper airway surgery on the upper airway. MR imaging and CT have allowed quantification of the airway and surrounding soft-tissue structures in three dimensions. Clinical indications for upper airway imaging are evolving for patients being treated with dental appliances and upper airway surgery.

Cephalometry↗