[Diseases in the area of the petrous bone: the value of high-resolution computed tomography].
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Cholesteatoma↗
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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.
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Primary tubercolous osteomyelitis of the sternum.
We present an 82-year-old woman with anterior sternal pain diagnosed as primary mycobacterial osteomyelitis of the sternum. She was treated with simultaneous wide resection and reconstruction of the chest wall. On admission, computed tomographic scan showed a sclerotic sternal mass with soft tissue reaction. Mycobacterium tuberculosis was grown in initial culture. First-line antituberculous medication and local debridement failed. The successful result was achieved by extensive sternal and chondral resection followed by simultaneous bilateral pectoralis major muscle flap positioning.
Aged↗
Computation of mass-density images from x-ray refraction-angle images.
In this paper, we investigate the possibility of computing quantitatively accurate images of mass density variations in soft tissue. This is a challenging task, because density variations in soft tissue, such as the breast, can be very subtle. Beginning from an image of refraction angle created by either diffraction-enhanced imaging (DEI) or multiple-image radiography (MIR), we estimate the mass-density image using a constrained least squares (CLS) method. The CLS algorithm yields accurate density estimates while effectively suppressing noise. Our method improves on an analytical method proposed by Hasnah et al (2005 Med. Phys. 32 549-52), which can produce significant artefacts when even a modest level of noise is present. We present a quantitative evaluation study to determine the accuracy with which mass density can be determined in the presence of noise. Based on computer simulations, we find that the mass-density estimation error can be as low as a few per cent for typical density variations found in the breast. Example images computed from less-noisy real data are also shown to illustrate the feasibility of the technique. We anticipate that density imaging may have application in assessment of water content of cartilage resulting from osteoarthritis, in evaluation of bone density, and in mammographic interpretation.
Absorptiometry, Photon↗
Improved optimization of soft-partition-weighted-sum filters and their application to image restoration.
Soft-partition-weighted-sum (Soft-PWS) filters are a class of spatially adaptive moving-window filters for signal and image restoration. Their performance is shown to be promising. However, optimization of the Soft-PWS filters has received only limited attention. Earlier work focused on a stochastic-gradient method that is computationally prohibitive in many applications. We describe a novel radial basis function interpretation of the Soft-PWS filters and present an efficient optimization procedure. We apply the filters to the problem of noise reduction. The experimental results show that the Soft-PWS filter outperforms the standard partition-weighted-sum filter and the Wiener filter.
Algorithms↗
Computed tomography and sialography: 1. Normal anatomy.
Computed tomography (CT) has made it possible to identify soft tissue structures not visible by sialography. This paper reviews the normal anatomy in the region of the parotid and submandibular glands in the axial transverse and coronal planes as imaged by CT before and after sialography. A clear understanding of the normal structures is important before undertaking an evaluation of disease.
Humans↗
Receiver-operating-characteristic study of chest radiographs in children: digital hard-copy film vs 2K x 2K soft-copy images.
Two methods are commonly used to visualize digital radiologic imaging data: (1) hard-copy viewing, in which the digital data are used to modulate the intensity of a laser beam that exposes an analog film and (2) soft-copy viewing, in which the digital data are converted to an analog video signal and presented on a CRT monitor. The film method allows new digital imaging systems to be easily integrated into conventional radiologic management and viewing methods. The second method, soft-copy viewing, allows digital imaging data to be managed and viewed electronically in a picture archiving and communication system (PACS). These PACS systems are hypothesized to have improved operational efficiency and enhanced image-analysis capabilities. The quality of soft-copy images is still not widely accepted. This article reports on the results of a large-scale receiver-operating-characteristic study comparing observers' performance in detecting various pediatric chest abnormalities on soft-copy 2048 x 2048K byte displays with their performance with digital laser-printed film from computed radiography. The disease categories studied were pneumothorax, linear atelectasis, air bronchogram, and interstitial disease. The selected data set included 239 images; 77 contained no proved abnormality and 162 contained one or more of the abnormalities mentioned. Seven pediatric radiologists participated in the study, two as judges and five as observers. Our results show no significant difference between viewing images on digital hard copy and soft copy for the detection of pneumothoraces and air bronchograms. A slight performance edge for soft copy was seen for interstitial disease and linear atelectasis. This result indicates that computed chest radiographs in children viewed in a soft-copy PACS environment should result in diagnoses similar to or slightly more accurate than those obtained in a laser-printed film-based environment.
Child↗
Computed tomography.
Although CT scanning has been available for less than 20 years, it has made a major impact on the practice of dentistry, particularly in oral and maxillofacial surgery, in the diagnosis and management of a wide variety of oral lesions. The use of computers to reconstruct x-ray attenuation data into an image allows the clinician to view pathology from many different perspectives, unobstructed by other anatomic structures, and to adjust contrast to concentrate on the soft-tissue and hard-tissue pathology in turn. Advances in computer software already allow three-dimensional visualization of pathology and anatomy, but additional refinements in this technology still are expected.
Humans↗
Pyocele of the middle turbinate: a case report.
Mucoceles are uncommon and the majority of cases occur in the frontoethmoidal complex. The accumulation of mucous secretion and eventual secondary infection may result in the formation of a pyocele of the middle turbinate, which is exceptionally rare. This case report presents a patient with a large pyocele of the middle turbinate invading the orbit. A 48-year-old woman presented with a three-week history of nasal obstruction, slight rhinorrhea, and headache. There was an external swelling of the nasal pyramid just near the medial canthus and right exophthalmos with bulging of the medial canthus of the ipsilateral eye. A computed tomography scan revealed a rounded, expansive lesion of soft tissue density. There was a thin compact bone at the margin. Under general anesthesia, resection of the lateral and inferior walls of the middle turbinate was performed. The large cystic mass was filled with pus. Exophthalmos and bulging of the medial canthus immediately disappeared. Histologic examination showed the mucocele wall with a ciliary respiratory epithelium.
Diagnosis, Differential↗
The computer and the law: coordinate analysis of skull shape and possible methods of postmortem identification.
Mechanisms accelerating or retarding the disintegration of soft tissues are briefly discussed, as well as the need to reconstruct the missing profile for postmortem identification purposes. The application of X-ray and computer-based analyses is discussed in the context of providing data to predict and reconstruct the most probable soft tissue profile of a dry skull. In addition, information from extensive studies of the facial bones and profiles of veterans has been applied to methods in forensic medicine of determining age, sex, and racial background of unknown subjects.
Black or African American↗
Soft tissue deformation.
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Biomechanical Phenomena↗
Linear attenuation coefficients for phantom materials simulating soft tissue.
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Acrylates↗
Facial growth of males and females compared by tensor analysis.
This study compares and contrasts the longitudinal differences in facial development between 18 male and 22 female subjects, employing the technique of tensor analysis. Children were examined in two age ranges: prepubertal (aged 7-10 years) and post-pubertal (15-20 years of age). Both the changes over time and the differences in amount and direction of growth between the sexes were subjected to statistical analysis. A tensor analysis permits the computation of differences in form (that is in size and shape) without specifically measuring either. Mean values for 21 hard and soft tissue landmarks were determined for both males and females at each age. Customized computer software allowed examination of the growth changes between 32 selected groups of points. Results indicated that the tensor analysis reinforced and supplemented the more conventional descriptions of facial growth. Females grew a smaller amount over the period examined than their male peers and development was in a relatively more vertical direction. These differences in growth between the sexes were highly statistically significant.
Adolescent↗
Hidden in health care reform: soft mandate for standard EDI.
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Computer Communication Networks↗
[Computer tomography in the diagnosis and therapy of acetabular fractures].
INTRODUCTION: Acetabular fractures and fracture dislocations of the hip joint are frequently complex, and the precise pathological anatomy is not easily demonstrated by routine radiographs. Conventional radiographs are often supplemented by oblique views [1]. The most commonly used classification of acetabular fractures has been based on conventional radiographs which are, in majority of cases, sufficient to determine the type of acetabular injuries [1-3]. It has been shown that computed tomography is useful method in precise evaluation of the fracture type the soft-tissue damage and integrity of joint space [4-6]. AIM: The aim of the study was to evaluate advantages of computed tomography in diagnosis of complex acetabular fractures. METHODS: We studied 737 patients with acetabular injuries over the period from 1989 to 1998. Five hundred and seventy five (78%) were males and 162 (22%) females. Eighty patients with acetabular fractures, with and with out hip dislocation, underwent pelvic CT following AP and 45 degrees oblique pelvic radiographs. Each patient was studied while supine, using 5 mm slice thickness at the acetabulum level and 10 mm at other parts of pelvis. Sections were obtained from the iliac crest to the greater trochanter [7]. RESULTS: The causes of acetabular fractures were: 621 (84.3%) patients participated in traffic accidents, 103 (14%) fell from a height, 7 (0.9%) covered in a mine and 6 (0.8%) were wounded. Femur was the most frequently associated injuries of all bones--155 (66.5%) (Graph 1). Permanent growth of acetabular fractures was noted from 1989 to 1993 regarding gender and years (Table 1), but that growth declined in 1993. It can be explained by a lower number of traffic accidents. Traffic, as an aetiological factor is nearly related with economic and energy crisis in our country (Graph 2). There were 176 (23.8%) fractures of the posterior wall, 23 (3.1%) fractures of the posterior column, 14 (1.9%) fractures of the anterior wall, 29 (3.9%) fractures of the anterior column. Transverse fractures were present in 61 patients (8.3%), "T" fractures in 51 (6.9%) patients and 383 (52.1%) were combined fractures. Of 80 patients loose bodies within the hip joint were noted on the CT scan in 77 (96%) patients, and only in 19 (24%) on radiographs. There was a statistically strong difference between methods (chi 2 = 12.376; p < 0.01). There was no significant difference between two methods in fracture of the femoral head detecting (chi 2 = 1.905; p > 0.05), but it has to bee noted that only two patients had fracture of the anterior aspect of the femoral head, both noted on CT but not on radiographs. In 78 (98%) versus 53 (66%) patients chondral defect of acetabulum was detected on radiografs. Difference was significant (chi 2 = 4.372; p < 0.05). Also, stability of the hip joint regarding size and location of the posterior wall fragment was better seen on CT than on radiographs (chi 2 = 5.555; p < 0.05). DISCUSSION: Our series demonstrates that in many cases details of acetabular fractures are not well visible on conventional radiographs. Because of the complexity of acetabular fractures, precise pathological anatomy is not easily demonstrated by routine radiographs. In a series of Pearson and Shirkhoda et al. [12,13], one third of acetabular fracture was not apparent on the initial radiographs; however, additional views taken three months later demonstrated a fracture. Mossed fractures should decrease with using the CT, which can also reveal the loose bodies in the joint space, occult femoral haed and chondral acetabular impaction. The size of the posterior wall fracture, and thus the stability of the hip, could be better determined by the CT scan than by a conventional radiograph. In conclusion, the information obtained from CT can help the surgeon to decide whether the surgery is necessary, and, if so, the proper approach. We believe that CT is a very helpful supplement to routine AP and 45 degrees oblique views when surgery of acetabular fractures is in question.
Acetabulum↗
Osteosarcoma: correlation between radiological and histological changes after intra-arterial chemotherapy.
The statistical correlation between three different radiological methods (conventional radiography, computed tomography and angiography) and tumor necrosis (TN) of the resected specimen have been studied in a series of 31 patients diagnosed with osteosarcoma (OS). They were treated with a multidisciplinary approach including intraarterial and intravenous chemotherapy followed by limb salvage procedures, plus intraoperative radiotherapy and adjuvant chemotherapy. A clear statistical correlation has been obtained between TN and angiography (p = 0.02) and between TN and two specific radiological signs: 'tumoral stain and neovascularity' (p = 0.02) and 'peritumoral fat planes' (p = 0.05). Conventional radiography, computed tomography and other radiological signs studied (nutrient vessel, soft tissue mass and central peripheral calcifications) did not show any significant correlation with TN. These results seem to suggest that angiography is a method to evaluate TN preoperatively and also to define the efficacy of neoadjuvant chemotherapy in OS.
Adolescent↗
Fatal Clostridium septicum myonecrosis.
A 20 year old leukaemic patient with neutropaenia secondary to chemotherapy, who developed overwhelming sepsis, myonecrosis, vascular occlusion and necrotizing enterocolitis due to Clostridium septicum infection is described. Plain abdominal radiographs and a computed tomography scan of the abdomen and pelvis showed gas in the retroperitoneal soft tissues. Clostridium septicum septicaemia has a recognized association with malignancy and neutropaenia and has a high mortality if not diagnosed and treated early. Computed tomography scanning of the abdomen, pelvis and head is advised in any patient with a positive C. septicum blood culture.
Acute Disease↗