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At least 883 records · Page 49Linked to original sources
PubMed2000

Low-cost soft-copy display accuracy in the detection of pulmonary nodules by single-exposure dual-energy subtraction: comparison with hard-copy viewing.

This study endeavored to clarify the usefulness of single-exposure dual-energy subtraction computed radiography (CR) of the chest and the ability of soft-copy images to detect low-contrast simulated pulmonary nodules. Conventional and bone-subtracted CR images of 25 chest phantom image sets with a low-contrast nylon nodule and 25 without a nodule were interpreted by 12 observers (6 radiologists, 6 chest physicians) who rated each on a continuous confidence scale and marked the position of the nodule if one was present. Hard-copy images were 7 x 7-inch laser-printed CR films, and soft-copy images were displayed on a 21-inch noninterlaced color CRT monitor with an optimized dynamic range. Soft-copy images were adjusted to the same size as hard-copy images and were viewed under darkened illumination in the reading room. No significant differences were found between hard- and soft-copy images. In conclusion, the soft-copy images were found to be useful in detecting low-contrast simulated pulmonary nodules.

Humans↗
PubMed1996

[Assessment of the results of surgical treatment of lymphedema based on computerized tomography].

The possibilities of computed tomographic appraisal of the qualitative and quantitative characteristics of the soft tissues in lymphedema of the lower limbs were studied in comparison with the results of pre- and postoperative examination of 21 out of 86 patients with Stage II-IV lymphedema. There were 4 males and 17 females, whose ages ranged from 16 to 41 years. In postoperative periods of 2 weeks to 6.5 years 45 computed tomographic studies were conducted. It was shown that computed tomography is an objective basis for appraising the qualitative and quantitative changes in the soft tissues of the limbs in follow-up patients with lymphedema after creation of lymphovenous anastomoses. The examination confirms objectively functioning of the lymphovenous anastomoses after disappearance of supra- and subfascial edema and diminution and even normalization of the thickness of the subcutaneous fat.

Adolescent↗
PubMed2001

Volume rendering of tendon-bone relationships using unenhanced CT.

OBJECTIVE: Clinically, three-dimensional CT of the extremities is most often used to display bony anatomy. However, by combining unenhanced CT with volume-rendering computer graphics, visualization of relationships between bone and soft-tissue structures such as muscle tendon is also possible. The aims of this study were to quantify CT attenuation values of peripheral tendon, muscle, and bone on unenhanced CT and to develop custom opacity transforms on the basis of the attenuation measurements to effectively depict tendon-muscle-bone relationships. CONCLUSION: The mean attenuation of peripheral tendon ( approximately 100 H) is distinctly higher than that of muscle ( approximately 60 H) enabling high-quality volume rendering of muscle-tendon-bone relationships with unenhanced CT. High-frequency (bone) CT reconstruction algorithms commonly used for extremity CT produce approximately twofold higher image noise and inferior three-dimensional renderings compared with those based on less noisy standard or soft-tissue reconstruction algorithms. These concepts can be used to uniquely reveal tendon-muscle-bone relationships for clinical, scientific, and educational purposes.

Adult↗
PubMed1984

Liposarcoma involving the scapula.

An unusual case of a soft tissue liposarcoma arising in the upper limb was studied by computed tomography. Computed tomography suggested the diagnosis of myxoid liposarcoma using the criteria of textural inhomogeneity and bony erosion and scalloping of the scapula.

Aged↗
PubMed1994

Subcutaneous granuloma annulare: four cases and review of the literature.

Subcutaneous granuloma annulare (SGA) produces benign nodules in otherwise healthy children. The histology of the lesions may be indistinguishable from rheumatoid nodules. However, in children the lesion of SGA is not accompanied by connective-tissue disease. We report 4 patients with SGA. There were three girls and one boy ranging in age from 4 to 15 years. All the children presented with a solitary lesion on the lower limb. A cutaneous lesion was also present in case 4. In only one patient (case 4) was there a history of trauma. There was no relevant past medical history. Routine laboratory tests were normal (including ESR and auto-immune profile). A computed tomography (CT) scan with intravenous contrast was performed in all patients. The CT features were those of soft tissue masses of variable attenuation and enhancement with inconsistent infiltration into surrounding fat. There appear to be no specific CT features which distinguish this benign lesion from a more sinister one. Excisional biopsy was performed in all cases. In children, SGA should be included in the differential diagnosis of soft-tissue masses, particularly in the lower extremity.

Adolescent↗
PubMed2006

A leiomyoma arising from the deep palmar arterial arch.

Vascular leiomyomas, or angioleiomyomas, are benign tumours originating from smooth non-striated muscle. Leiomyomas in the hand are uncommon and their pre-operative diagnosis is difficult. We report a 65 year-old woman who developed a vascular leiomyoma arising from the deep palmar arterial arch.

Aged↗
PubMed1997

CT and MR imaging in the local staging of primary malignant musculoskeletal neoplasms: Report of the Radiology Diagnostic Oncology Group.

PURPOSE: To assess the relative accuracies of computed tomography (CT) and magnetic resonance (MR) imaging in the local staging of primary malignant bone and soft-tissue tumors. MATERIALS AND METHODS: At four institutions, 367 eligible patients (aged 6-89 years) with malignant bone or soft-tissue neoplasms in selected anatomic sites were enrolled. Patients underwent both CT and MR imaging within 4 weeks before surgery. In each patient, CT scans were interpreted independently by two radiologists and MR images by two other radiologists at the enrolling institution. The CT and MR images were then interpreted together by two of those radiologists and subsequently reread at the other institutions. Imaging and histopathologic findings were compared and were supplemented when needed with surgical findings. Receiver operating characteristic curve analysis and descriptive statistical analysis were performed. RESULTS: Cases were analyzable in 316 patients: 183 had primary bone tumors; 133 had primary soft-tissue tumors. There was no statistically significant difference between CT and MR imaging in determining tumor involvement of muscle, bone, joints, or neurovascular structures. The combined interpretation of CT and MR images did not statistically significantly improve accuracy. Interreader variability was similar for both modalities. CONCLUSION: CT and MR imaging are equally accurate in the local staging of malignant bone and soft-tissue neoplasms in the specific anatomic sites studied.

Adolescent↗
PubMed1999

Percutaneous biopsy of the musculoskeletal system: a review of 77 cases.

OBJECTIVE: To analyze the accuracy of percutaneous bone and soft-tissue biopsies. METHODS: A total of 77 percutaneous biopsies performed under computed tomographic or fluoroscopic guidance over a 24-month period were reviewed. The biopsies were performed in 74 patients, 32 male and 42 female, with a mean age of 60.3 years. RESULTS: Sixty-three bone and 14 soft-tissue biopsies were performed. No follow-up information was available for 8 patients, and 1 patient died before an accurate diagnosis could be made. There were 44 true-positive, 17 true-negative, 8 false-negative and no false-positive results. The correct diagnosis was obtained in 57 of 68 cases (83.8%). For bone biopsies, the accurate diagnosis was obtained in 47 of 55 cases (85.5%). For soft-tissue biopsies, the correct diagnosis was obtained in 10 of the 13 cases (76.9%). Diagnostic accuracy was slightly better for osteolytic than for osteosclerotic lesions. Accuracy also varied with lesion site and needle type. Cytology and pathology specimens were almost equally useful in contributing to the correct diagnosis. CONCLUSION: The accuracy of percutaneous biopsy achieved in this series is similar to that found in other series. Although diagnostic accuracy varied, accuracy is improved if both cytologic and pathologic specimens are analyzed.

Adolescent↗
PubMed1985

Computed tomography of orthopedic neoplasms.

CT facilitates diagnosis of orthopedic neoplasms by recognition of both the internal contents of the lesion and its borders with surrounding soft tissues. Involvement of adjacent vital organs and spread within the medullary canal are important for planning resection or amputation. Changes in the size of the lesion may be seen on CT scans following radiation therapy, and metastatic lesions to bone and lungs may be detected with high sensitivity. Biopsy performed with CT guidance is both safe and effective.

Biopsy↗
PubMed1992

Changes in the linear attenuation coefficient of canine appendicular bone following intravenous infusion of strontium lactate, measured using gamma-ray computed tomography.

Changes in the average linear attenuation coefficient (LAC) within a fixed measurement volume in the proximal end of the dog tibia, which contains trabecular bone and associated soft tissues (the trabecular bone "space"), were monitored continuously using gamma-ray computed tomography (gamma-CT) prior to, during, and following intravenous infusion of strontium (Sr) lactate. An infusion of 1.3-4.7 g of Sr over a period of 110-160 minutes into 20-kg dogs resulted, within 6-8 hours, in an increase of 0.019-0.045 cm-1 (P less than 0.002) in the LAC. Calibration of the gamma-CT system showed that 0.44 mg/cm3 of Sr produced a change of 0.01 cm-1 in the LAC. Using this conversion factor, the Sr concentration in the trabecular bone space resulting from infusion, as measured by flame atomic absorption spectroscopy, agreed with that predicted by the change observed in the LAC. Sr present in the serum and urine was consistent with the changes observed in the LAC over the study period. Control dogs infused with mineral-free solutions showed no change in LAC. Calcium equivalents required to give the changes observed in the LAC using Sr indicate that variations in skeletal turnover in man can be monitored in the peripheral skeleton using gamma-CT.

Animals↗
PubMedDate not supplied

Tuberculosis of the chest wall: CT findings.

To assess the CT features of tuberculosis of the chest wall, the CT findings in four patients with documented tuberculous chest wall infection were reviewed. Two patients were Caucasian and two were of Chinese origin. All had normal immune status. In two cases tuberculosis involved the ribs, in one the costal cartilage, and in one the sternoclavicular joint. Computed tomography demonstrated osseous and cartilaginous destruction (in four), soft tissue masses with calcification (in two), and rim enhancement following intravenous contrast medium administration (in two). Underlying pleuroparenchymal tuberculosis was present in two cases. Tuberculosis of the chest wall is characterized by bone or costal cartilage destruction and soft tissue masses that may demonstrate calcification or rim enhancement with or without evidence of underlying lung or pleural disease.

Adult↗
PubMed2002

Volumetric implant-planning based on Symmetry Considerations.

Symmetry Considerations can be used not only to plan the desired shape of reconstructured bone structures, but also to generate prototypes for soft tissue implants. The poster describes a system which allows to calculate a symmetry plane in the facial area automatically and computes proposals for implants or transplants. The system presented has been used to calculate soft tissue implants and a replacement for parts of the lower jaw.

Cephalometry↗
PubMed1994

Biomolecular computing: from the brain-machine disanalogy to the brain-machine analogy.

The analogy between the main information features of the brain and molecular non-discrete information processing devices based on non-linear dynamic mechanisms is considered. These information processing mechanisms predetermine the character of basic primitive operations of these devices, which seem to be capable of solving problems of a rather high computational complexity. Non-linear dynamic processing mechanisms open the way to elaboration of devices embodying, in a natural way, the fuzziness of information features that is typical of information processing inherent in soft 'humanistic' systems.

Brain↗
PubMed2006

Three-dimensional assessment of the facial soft tissue changes that occur postoperatively in orthognathic patients.

With the development of 3-dimensional technology it has become increasingly possible to record the facial soft tissue changes that occur with growth and following orthodontic treatment. This article describes the use of the optical surface laser scanner to record and quantify the facial soft tissue changes following orthognathic surgery. Ten skeletal Class III patients were laser scanned, at previously determined time intervals, over a 6-month period following orthognathic surgery. Computer superimposition of the scanned images provided a graphic demonstration of the soft tissue changes as they occurred between the time intervals. Analysis of the results demonstrates a nonuniform, asymmetric resolution of facial swelling and adaptation of the soft tissues to the altered skeletal structure. This occurred principally over the initial 4 months following surgery. However, smaller changes continued to occur throughout the study period. This suggests that the facial soft tissues continue to change over a period of greater than 6 months. This knowledge is important as it is integral for obtaining informed consent from patients.

Cephalometry↗
PubMed1989

Hepatocellular carcinoma presenting as bone metastasis.

In a consecutive series of 395 patients with pathologically verified hepatocellular carcinoma, 20 patients (5%) had bone metastasis at initial presentation. Of these, 16 were men and four women ranging from 26 to 64 years of age (median, 50 years). The age, sex, hepatitis B surface antigen seropositivity, alpha-fetoprotein level, and frequency of associated cirrhosis were not statistically different from those in patients without initial bone metastasis. Initial presentation was usually the result of spinal lesion with neurologic compression, and chest wall or scalp mass. Metastasis most commonly involved spine and ribs, and occurred as osteolytic lesions or extrapleural mass. Computed tomography proved best for demonstrating an expansile soft tissue mass with bony destruction. Angiography showed hypervascular appearance over the destructive bone area. Treatment results were poor. The follow-up period ranged from 3 weeks to 14 months with a median survival of 5 months. The data suggested that hepatocellular carcinoma be ruled out in patients with osteolytic lesions.

Adult↗
PubMed2002

Ultrastructural analyses of pancreatic grafts preserved by the two-layer cold-storage method and by simple cold storage in University of Wisconsin solution.

The two-layer cold storage method (TLM) using University of Wisconsin (UW) solution supplies sufficient oxygen to pancreatic grafts during preservation and extends pancreas preservation time to up to 96 h in the canine model. Simple cold storage in UW (UWM) on the other hand, preserves canine pancreas grafts for up to 72 h by preventing cell swelling, mainly because of its high osmotic pressure. The aim of this study is to analyze morphologically dog pancreatic grafts preserved by these two methods with their different mechanisms. Immediately after preservation of canine pancreata by TLM for 72 h and 96 h (group 1 and group 3, respectively), and by UWM for 72 h and 96 h (group 2 and group 4, respectively), tissue ATP levels were determined using high-performance liquid chromatography (HPLC), and detailed morphological analyses of intragraft components were performed using light- and electron microscopy. The mean areas of one mitochondrion and rough endoplasmic reticulum (RER) vacuolization were calculated by computer-graphic analyses using NIH image 1.62 f soft. The tissue ATP levels were significantly higher in groups 1 and 3 than groups 2 and 4 ( P < 0.05). Light microscopy demonstrated no marked difference among the 4 groups. By electron microscopy however, mitochondrial swelling and RER vacuolization were observed in acinar cells to various extents in the 4 groups. They were significantly more evident in group 2 than group 1 ( P < 0.05), and in group 4 than group 3 ( P < 0.05). In conclusion, TLM demonstrated excellent protection of intracellular organelles, mitochondria, and RER, up to 72-96 h. Well-maintained graft ATP levels in TLM groups may result in maintaining the integrity of intracellular organelle membranes as well as cellular membranes.

Adenosine↗
PubMed1994

Image analysis of lateral velopharyngeal closure in repaired cleft palates and normal palates.

We have undertaken the design and testing of a system for making measurements of velopharyngeal function from lateral videofluoroscopic images based upon standard equipment found in any cleft clinic. The uncertainties in the measurements have been found to be acceptably low and, in conjunction with other measurement techniques, the system has made a valuable contribution to the assessment of velopharyngeal function. Additional measurements using this system are presently being developed.

Cleft Lip↗