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 721 records · Page 40Linked to original sources

PubMed1996

Refining silicone implant correction of pectus excavatum through computed tomography.

Silicone implant correction of pectus excavatum has yielded satisfactory results in asymptomatic patients. Problems have been encountered with accurate implant fabrication and fit due to the soft-tissue masking of actual sternal contours. We have employed computed tomography to reconstruct the pectus deformity to improve implant design and fit. Instability can be prevented with the reduced need for intraoperative manipulation as well.

Adolescent↗

PubMed1985

Soft-tissue abnormalities of the external auditory canal: subject review of CT findings.

We review the normal anatomy and discuss characteristic findings of soft-tissue abnormalities of the external auditory canal (EAC). The indications for computed tomography (CT) of the temporal bone have been significantly expanded with the inclusion of soft-tissue abnormalities of the external ear and the auditory canal. Soft-tissue abnormalities of the EAC that can be evaluated with CT include atresia, edema, hemorrhage, fracture, posttraumatic or infection-caused keloid, malignant external otitis, hemangioma, lymphangioma, papilloma, keratosis obturans, acquired cholesteatoma, adenoma, ceruminoma, fibroma, mixed tumor, sarcoma, and basal cell, squamous cell, or adenocystic carcinoma. CT scans of 25 patients who had soft-tissue abnormalities of the EAC were reviewed. The clinical data were correlated with the radiographic findings. We conclude that CT is the best overall radiographic modality for evaluating the extent and character of soft-tissue abnormalities of the EAC. Significant clinical information that is helpful in patient management decisions is added by this technique.

Adenoma↗

PubMed2004

High-performance selective excitation pulses for solid- and liquid-state NMR spectroscopy.

Computer-optimized selective pulses are routinely used in solution-state NMR spectroscopy. At the same time, their utility and importance for solid-state applications has yet to be fully realized. We suggest a new computational approach that makes the design of soft selective pulses with desired properties relatively straightforward. By applying this technique to the generic selective excitation problem, we have arrived at a family of high performance selective excitation pulses, dubbed E-Family, that allows more flexibility and better performance than analogous pulses previously reported in the literature. The new pulses have been successfully tested in both solid- and solution-state NMR experiments. A theoretical treatment of the effects of chemical shift anisotropy (CSA) on the selective excitation in magic-angle spinning (MAS) experiments in solids is presented. The set of heuristics that comprise our new strategy were incorporated into a general NMR simulation program SPINEVOLUTION.

Anisotropy↗

PubMed2006

Primary malignant melanoma of the middle ear mucosa: a case report.

Primary involvement of the middle ear and mastoid mucosa by malignant melanoma (MM) has been rarely reported. We report an 81-year-old Caucasian woman presenting with otalgia, left-sided aural fullness, and hearing loss. Otoscopic examination revealed a purple-colored polyp that appeared to be vascular, occupy left external auditory canal (EAC). The computed tomography scanning showed a mass in soft tissue density, filling the tympanic and mastoid cavities, eroding the mastoid cortex, and invading medial and central parts of the EAC. A biopsy was performed with the diagnosis of MM. The patient underwent subtotal temporal bone resection with radical neck dissection. Dacarbazine was given postoperatively. The case presented herein emphasizes the need to be aware that MMs can arise in the middle ear and mastoid cavity. An index of suspicion in the differential diagnosis of temporal bone tumors is necessary for early recognition.

Aged↗

PubMed1987

[Computed tomography of primary and secondary tumors of the eye and orbit].

Only computed tomography (CT) is able to demonstrate ocular, orbital and peri-orbital soft tissues, calcification and bony structures directly and without superimposition of other tissues. 165 patients with tumours of the eye or orbit have been examined by CT and in 143 the diagnosis has been confirmed. The value of CT lies in its ability to demonstrate tumours and to define their orbital and extra-orbital extension and their relationship to neighbouring structures. In 51% of the lesions there was bone destruction and in 6% intracranial extension. Density measurements before and after intravenous contrast medium only rarely provided a specific diagnosis.

Adolescent↗

PubMed1997

Distraction osteogenesis for lengthening of the hard palate: Part II. Histological study of the hard and soft palate after distraction.

To correct velopharyngeal incompetence, a new treatment concept was proposed in Distraction Osteogenesis for Lengthening of the Hard Palate: Part I (using lengthening of the hard and soft palate by distraction osteogenesis). Cephalometry and computed tomography showed successful elongation of the posterior hard palate with gradual calcification. Here the sequential use of fluorochrome markers (oxytetracycline, xylenol orange, DCAF [2,4-bis-N-N'-dicarboxymethyl aminomethyl fluorescein], and alizarin complexone) during the distraction and retention period is reported together with the histologic investigations using light and laser scan microscopy without prior demineralization. The experimental gap showed de novo osteogenesis in all dogs. The new bone was always in continuity with the original anterior and posterior palatal bone margins. It either bridged the experimental gap fully or left a small central zone of fibrous tissue, in which eventual ossification occurred. Several distinct zones could be distinguished: A small central zone was found with parallel strains of collagen fibers, oriented longitudinally in the direction of the distraction. Next to this zone a layer of undifferentiated mesenchymal precursor cells was seen in direct contact to newly formed bone. The next zone was coarse woven bone, showing a transition to mature lamellar bone through remodeling. No evidence of endochondral bone formation was found, i.e., all dogs showed exclusively intramembranous bone formation. The soft tissues showed no signs of alteration: in particular, there was no necrosis or scar formation. The soft tissues were not thinned but appeared to have followed the longitudinal displacement. In conclusion, gradual distraction osteogenesis of the hard palate could be a possible method for lengthening the palate to treat velopharyngeal incompetence.

Animals↗

PubMed1996

Radiation dose reduction in computed skeletal radiography. Effect on image quality.

PURPOSE: To evaluate the effect of radiation dose reduction on image ++quality in computed musculoskeletal radiography and determine optimal exposure range. MATERIAL AND METHODS: In 11 corpses, 1 hand and 1 hip were examined with film-screen radiography, and a series of computed radiographs was obtained using exactly the same technique except for the exposure, which was 100, 50, 25, 12.5, 6.25, and 1.56% of the mAs numbers used for the film-screen images. The computed hip radiographs were processed in 2 different ways, one simulating the film-screen images and one using contrast enhancement. Four radiologists reviewed the images regarding the following parameters: cortical bone, trabecular bone, joint space, and soft tissue, giving each a diagnostic quality rating on a scale from 1 to 5. The median and mean values were found for the pooled results. RESULTS: For the hands, the computed radiographs were ranked inferior to the film-screen images for all parameters except soft tissue, where the computed radiographs scored higher. The computed images with 50 and 25% exposure were ranked equal to the 100% ones. The quality rating slowly declined with lower exposures. For the hips, the 100 and 50% computed radiographs were generally similar to or slightly better than the film-screen images. The decline was somewhat faster than for the hands. The contrast-enhanced hip images scored less than the nonenhanced images at any given exposure for all parameters except soft tissue, where the contrast-enhanced images scored better at all exposures. The difference between nonenhanced and enhanced images became less at the lower exposures. CONCLUSION: Lowering the exposure in computed musculoskeletal radioagrphy below the level of film-screen radiography is feasible, especially in the peripheral skeleton. Contrast enhancement seems to be valuable only in the evaluation of soft-tissue structures.

Bone and Bones↗

PubMed2003

MEG source localization using an MLP with a distributed output representation.

We present a system that takes realistic magnetoencephalographic (MEG) signals and localizes a single dipole to reasonable accuracy in real time. At its heart is a multilayer perceptron (MLP) which takes the sensor measurements as inputs, uses one hidden layer, and generates as outputs the amplitudes of receptive fields holding a distributed representation of the dipole location. We trained this Soft-MLP on dipolar sources with real brain noise and converted the network's output into an explicit Cartesian coordinate representation of the dipole location using two different decoding strategies. The proposed Soft-MLPs are much more accurate than previous networks which output source locations in Cartesian coordinates. Hybrid Soft-MLP-start-LM systems, in which the Soft-MLP output initializes Levenberg-Marquardt, retained their accuracy of 0.28 cm with a decrease in computation time from 36 ms to 30 ms. We apply the Soft-MLP localizer to real MEG data separated by a blind source separation algorithm, and compare the Soft-MLP dipole locations to those of a conventional system.

Algorithms↗

PubMedDate not supplied

[Spontaneous pneumothorax caused by lung metastasis of sarcoma of the thigh].

Relapsing spontaneous pneumothorax can be the first manifestation of pulmonary metastases of soft tissues sarcomas. Standard imaging techniques and computed tomography may not be able to detect small malignant cystic lesion or to distinguish between them and benign bollous lesions. We report the case of a 33 year-old male who, in the past, underwent surgical treatment for a synovial sarcoma of the inferior limb. The patient was admitted to our hospital because of right spontaneous pneumothorax; both chest x-ray and CT scan didn't detect any metastatic pulmonary lesion. A few days after the discharge the patient was readmitted because of relapsed pneumothorax; high-definition CT of the chest revealed a pulmonary cystic lesion that was resected thoracoscopically. Histological examination revealed a pulmonary metastases of synovial sarcoma.

Adult↗

PubMed2000

Imaging of soft-tissue sarcomas.

A multidisciplinary approach that includes active participation by a radiologist is beneficial for optimal diagnostic evaluation and treatment of soft-tissue sarcomas. Recent advances in diagnostic imaging include a better understanding of the practical roles of ultrasonography, computed tomography, and magnetic resonance imaging in the evaluation of primary and recurrent soft-tissue sarcomas. The potential role of positron emission tomography scanning and dynamic magnetic resonance imaging in the evaluation of soft-tissue sarcomas has been preliminarily evaluated. The clinically practical utility of radiologic imaging in the evaluation of soft-tissue sarcomas is discussed, and ongoing research is briefly reviewed.

Diagnosis, Differential↗

PubMed2005

[A four-year-old boy with swollen cheek after a fall].

A four-year-old boy had fallen from a tree in nursery school and had minor symptoms immediately after the trauma. He was admitted to the local casualty clinic the same night, but no signs of local injury were detected. The next morning he was admitted to the department of oto-rhino-laryngology at the local hospital due to increasing local swelling and pain in the cheek. A computed tomography examination demonstrated an extensive preauricular soft tissue swelling and a long central hypodensity from the left ear to the oropharynx. The presence of a penetrating foreign body was suspected and the boy was admitted to our hospital. An examination in general anaesthesia revealed a small skin lesion medial to the tragus in the left external auditory meatus and a wooden stick was seen crossing the oropharynx. The eight and a half centimetre long wooden stick had penetrated from the cartilaginous part of the left external auditory meatus to the right palatal tonsil. It was removed through a pre-auricular incision. No complications were observed and the boy could leave the hospital after four days of observation with antibiotic therapy and tetanus prophylaxis.

Accidental Falls↗

PubMed2002

Bone ingrowth on a smooth-surfaced hydroxyapatite-coated acetabular cup.

We studied 29 retrieved smooth-surfaced hydroxyapatite (HA)-coated acetabular cups that had been in situ for an average of 54.9 months. The outer surface of all cups carried two circular grooves dividing the smooth surface. The extent of bony in-growth and hydroxyapatite absorption was calculated using a computer imaging system (analySIS-pro 3.0, Soft Imaging System GmbH, Germany). Absorption of HA was seen in all 29 cups. The extent of absorption was, on average, 60.5%. Twenty-five cups showed bony in-growth covering an average of 13.8% of the cup surface. Thirteen cups showed bony in-growth on the smooth surface as well as the circular grooves. On 11 cups, the bony in-growth was confined to the grooves. We found that bony in-growth on the smooth-surfaced HA-coated acetabular cup was minimal. It occurred along the two circular grooves rather than on the smooth surfaces. We conclude that a macro-structure surface enhancing bony in-growth is necessary for the long-term survival of the studied cup.

Acetabulum↗

PubMed1983

High-resolution CT analysis of facial struts in trauma: 2. Osseous and soft-tissue complications.

In six cadavers, high-resolution thin-section computed tomography (CT) was used to evaluate the sequelae of experimentally produced facial trauma. As confirmed by pluridirectional tomography, CT was an effective imaging method for the detection and classification of facial fractures. The ability of CT to simultaneously depict both osseous and soft-tissue structures expands the role that diagnostic radiology can play in the evaluation of the traumatized face. A method of evaluation is presented in which the face is geometrically conceptualized as a series of triplanar (horizontal, sagittal, and coronal) osseous struts. Sequential, systematic assessment of each strut for fracture and its adjacent soft tissue for injury can facilitate evaluation of the traumatized face. Using this approach the osseous and soft-tissue complications arising from experimentally produced trauma are reviewed and illustrated with CT. Examples of potential soft-tissue complications that may occur with fractures of the horizontal group of struts include disruption of the dura matter at the cribiform plate, involvement of the structures of the anterior cranial fossa, injury to the optic nerve, and involvement of the superior and inferior groups of extraocular muscles. Injury to the nasolacrimal duct, maxillary sinus ostium, medial and lateral rectus muscles, or the soft-tissue structures in the superior and inferior orbital fissures may arise from disruption of the sagittal struts. Fractures of the coronal struts may involve the frontal sinus, anterior cranial fossa, lacrimal gland, nasofrontal duct, lacrimal sac, or the soft tissues of the pterygopalatine fossa.

Face↗

PubMed1982

Diagnosis of acromegaly on cranial computed tomography.

The characteristic features of acromegaly as demonstrated on cranial computed tomography (CT) are described. These features relate to the increased soft tissue bulk and overpneumatization of sinuses and air cells, as well as the generalized bony overgrowth associated with high growth hormone (GH) levels. In the assessment of these features, the computer window settings must be adjusted accordingly for separate visualization of soft tissues, calvarial bones and cerebral tissue on the scan images. We found positive features in CT scans of 13 patients with established acromegaly and were able to suggest the diagnosis prospectively in 2 additional cases. The finding of an enlarged pituitary fossa should lead the radiologist to search carefully for the ancillary signs of acromegaly on the scans, thus confirming the diagnosis. When an enlarged sella turcica or an enhancing intrasellar mass is not demonstrated, the recognition of the other features on cranial CT scans may be important in suggesting the diagnosis of acromegaly to the clinician.

Acromegaly↗

PubMed2004

Gastroesophageal intussusception: a new cause of acute esophageal obstruction in children.

Gastrointestinal intussusception with obstruction is common in the small bowel and colon; however, such a process is not known to cause esophageal obstruction. Recent experience with gastroesophageal intussusception permits discussion of diagnosis and consideration of treatment options. A 3-year-old child presented with acute esophageal obstruction. Physical examination was significant for epigastric tenderness and excessive salivation. Chest x-ray showed a posterior mediastinal fullness. Esophagram documented a smooth crescent-filling defect, which caused obstruction of the esophagus at the level of the carina with proximal esophageal dilatation. Chest computed tomography of the thorax showed a soft tissue mass of the distal esophagus. Esophagoscopy confirmed occlusion of the midesophagus with the mucosa intact. A right thoracotomy permitted visualization of dilated proximal esophagus and a palpation of an intraluminal mass in the distal esophagus. Mobilization of the distal esophagus and gentle manual pressure cleared the obstruction to a point below the diaphragm. After a normal intraoperative esophagram, final treatment consisted of a longitudinal esophagomyotomy. The child recovered without complication and continues without recurrence for 18 months. This is the first report of gastroesophageal intussusception in children. Management by thoracotomy, manual reduction, and esophageal myotomy reestablished intestinal continuity and appears to eliminate recurrence; fundoplication or gastropexy may be alternative options. Preoperative recognition of gastroesophageal intussusception may allow nonoperative reduction or treatment by minimally invasive surgery.

Child, Preschool↗

PubMed1989

Hickman nodule: a mimic of metastatic disease.

A characteristic small subcutaneous soft-tissue mass can be seen on the computed tomographic scans of patients after removal of Hickman catheters. The mass is indistinguishable from subcutaneous metastatic deposits seen with a variety of malignant tumors. This potentially confusing finding can be differentiated from true metastatic disease by the characteristic location of the subcutaneous nodule in the second or third anterior intercostal space, along the midclavicular line, and by the absence of other subcutaneous masses.

Catheterization, Central Venous↗

PubMed2005

[Use of a 3-oxypiridine antioxidant in combined therapy of patients with partial epilepsy].

Fifty-four patients with partial epilepsy (age 18-50 years, 26 males and 28 females, illness duration from 6 months to 18 years) have been examined. Idiopathic epilepsy was diagnosed in 7 patients, symptomatic in 36, cryptogenic in 11. The control group comprised 22 sex- and age-matched individuals. All the patients underwent computerized EEG and pharmaco-EEG testing, MRI or CT of the brain. Follow-up duration was from 6 months to 2.5 years. An antioxidant therapeutic course was conducted during 30 days on the background of the basic anticonvulsive therapy with carbamazepine (finlepsin-retard 200) received in individual dosages. Computer EEG analysis was made using "BRAINWIN" soft (Mitrofanov A.A., "Statokin", Moscow). To estimate the effect of the medications on bioelectric brain activity, methods of spectral and coherent EEG analysis, localization of equivalent dipole source of paroxysmal activity were applied. After a 30-day course of combined therapy with carbamazepine (finlepsin-retard 200) and antioxidant Mexicor, inhibition of generator activity of limbic and hypothalamic as well as stem and cerebellum structures and displacement of generator zones into cortical hemisphere structures were observed that may be explained by enhancement of determinant foci of the cortical structures in inhibition of secondary foci. It may be considered as a favorable prognostic factor, which reduces probability of the secondary generalization of partial epileptic seizures.

Adolescent↗

PubMed2005

Modeling biologic soft tissues for haptic feedback with an hybrid multiresolution method.

The simulation of realistic surgical procedures requires specialized optimized algorithms for the models of organs and tissues, which should comply both with accuracy of results and run-time computation. This paper provides a numerical method for implementing deformation of soft tissues for haptic feedback that makes use of a hybrid pre-computation scheme.

Algorithms↗