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At least 703 records · Page 39Linked to original sources
PubMed1987

[Instrumental diagnosis of non-glandular superficial inflammation].

The study of soft tissues has greatly improved since the introduction of ultrasonography (US) and computed tomography (CT). In order to define the role of instrumental investigations, 51 patients affected by non glandular superficial soft tissue masses underwent US and 9 were also examined with CT. US proved to be accurate to define the size, the structure of the mass (93%), the benign or malignant nature (91%). US was also useful for percutaneous biopsy. However, US cannot be considered the only investigation because it does not give enough data about bony and articular structures: a conventional X-ray film must be performed in order to define the relation of the mass with the adjacent bone and to clarify the possible presence of fatty tissue in a solid mass shown at US. CT has a role in case of large masses, surrounding a bone diaphysis, when the malignant nature is suspected and to define the relationship with vessels and muscles.

Abscess↗
PubMed2005

The application of FLUKA to dosimetry and radiation therapy.

The FLUKA Monte Carlo code has been evolving over the last several decades and is now widely used for radiation shielding calculations. In order to facilitate the use of FLUKA in dosimetry and therapy applications, supporting software has been developed to allow the direct conversion of the output files from standard CT-scans directly into a voxel geometry for transport within FLUKA. Since the CT-scan information essentially contains only the electron density information over the scanned volume, one needs the specific compositions for each voxel individually. We present here the results of a simple algorithm to assign tissues in the human body to one of four categories: soft-tissue, hard-bone, trabecular-bone and porous-lung. In addition, we explore the problem of the pathlength distributions in porous media such as trabecular bone. A mechanism will be implemented within FLUKA to allow for variable multipal fixed density materials to accommodate the pathlength distributions discovered.

Algorithms↗
PubMed2002

An unusual case of noncavitary hemorrhage revealed by intravenous contrast-enhanced computed tomography.

Peripheral arterial injuries after blunt trauma commonly follow injuries to adjacent soft tissue, organ, and bone. We present here a case of blunt injury to the lumbar artery and the deep iliac circumflex artery in which there was no adjacent bone fracture, but in which hemorrhagic shock and persistent anemia ensued. Intravenous contrast-enhanced computed tomography revealed the site of active bleeding, leading us to perform an angiographic embolization for hemostasis.

Accidents, Traffic↗
PubMed1986

Imaging sacral nerve root cysts.

Sacral nerve root cysts usually are an incidental finding but may be found in patients with a history of pain. On computed tomography they are demonstrated as a soft tissue mass, possibly with associated bony erosion. Demonstrating the fluid-filled nature of these masses is important in establishing the diagnosis. The imaging of these cysts in two patients, including magnetic resonance, is described.

Aged↗
PubMed2006

Soft tissue balance in total knee arthroplasty: does stress relaxation occur perioperatively?

The restoration of correct soft tissue tension is key to achieving a successful total knee arthroplasty. However, it remains unclear whether the status achieved immediately after the operation will persist over time. Some surgeons believe soft tissue stress relaxation occurs and therefore the knee loosens somewhat after the procedure. It was the aim of this study to investigate this hypothesis. We analyzed 25 in vivo total knee implantations using contemporary computer navigation technology to assess and quantify perioperative soft tissue relaxation. Mediolateral joint laxity and maximal passive extension were analyzed immediately intraoperatively and 30 minutes later under the same conditions. Stress relaxation occurred in all cases, leading to increased mediolateral laxity by an average of 1 mm on the medial and lateral sides. Maximal passive extension increased by an average of 3 degrees. This data confirms the hypothesis the knee becomes looser in the early phase after total knee arthroplasty.

Arthroplasty, Replacement, Knee↗
PubMed2003

Clinics in diagnostic imaging (85). Mandible osteoradionecrosis complicated by infection.

Mandibular osteoradionecrosis is a rare but well-known complication that may be seen in patients with head and neck tumours following radiation therapy. A 42-year-old man presented with painful soft tissue swelling and a discharging sinus over the right mandible. Radiographs showed osteolytic destruction. Computed tomography confirmed bony destruction and fragmentation, as well as signs of soft tissue infection. The diagnosis of mandible osteoradionecrosis complicated by infection was confirmed by biopsy and surgically. The clinical and imaging features of osteoradionecrosis are highlighted.

Adult↗
PubMed1993

Quantitative analysis of bone reactions to relative motions at implant-bone interfaces.

Connective soft tissues at the interface between implants and bone, such as in human joint replacements, can endanger the stability of the implant fixation. The potential of an implant to generate interface bone resorption and form soft tissue depends on many variables, including mechanical ones. These mechanical factors can be expressed in terms of relative motions between bone and implant at the interface or deformation of the interfacial material. The purpose of this investigation was to determine if interface debonding and subsequent relative interface motions can be responsible for interface degradation and soft tissue interposition as seen in experiments and clinical results. A finite element computer program was augmented with a mathematical description of interface debonding, dependent on interface stress criteria, and soft tissue interface interposition, dependent on relative interface motions. Three simplified models of orthopaedic implants were constructed: a cortical bone screw for fracture fixation plates, a femoral resurfacing prosthesis and a straight stem model, cemented in a bone. The predicted computer configurations were compared with clinical observations. The computer results showed how interface disruption and fibrous tissue interposition interrelate and possibly enhance each other, whereby a progressive development of the soft tissue layer can occur. Around the cortical bone screw, the predicted resorption patterns were relatively large directly under the screw head and showed a pivot point in the opposite cortex. The resurfacing cup model predicted some fibrous tissue formation under the medial and lateral cup rim, whereby the medial layer developed first because of higher initial interface stresses. The straight stem model predicted initial interface failure at the proximal parts. After proximal resorption and fibrous tissue interposition, the medial interface was completely disrupted and developed an interface layer. The distal and mid lateral side maintained within the strength criterion. Although the applied models were relatively simple, the results showed reasonable qualitative agreement with resorption patterns found in clinical studies concerning bone screws and the resurfacing cup. The hypothesis that interface debonding and subsequent relative (micro)motions could be responsible for bone resorption and fibrous tissue propagation is thereby sustained by the results.

Biomechanical Phenomena↗
PubMed1998

Finite element implementation of anisotropic quasi-linear viscoelasticity using a discrete spectrum approximation.

The objective of this work was to develop a theoretical and computational framework to apply the finite element method to anisotropic, viscoelastic soft tissues. The quasilinear viscoelastic (QLV) theory provided the basis for the development. To allow efficient and easy computational implementation, a discrete spectrum approximation was developed for the QLV relaxation function. This approximation provided a graphic means to fit experimental data with an exponential series. A transversely isotropic hyperelastic material model developed for ligaments and tendons was used for the elastic response. The viscoelastic material model was implemented in a general-purpose, nonlinear finite element program. Test problems were analyzed to assess the performance of the discrete spectrum approximation and the accuracy of the finite element implementation. Results indicated that the formulation can reproduce the anisotropy and time-dependent material behavior observed in soft tissues. Application of the formulation to the analysis of the human femur-medial collateral ligament-tibia complex demonstrated the ability of the formulation to analyze large three-dimensional problems in the mechanics of biological joints.

Biomechanical Phenomena↗
PubMed2001

Whiplash injury determination with conventional spine imaging and cryomicrotomy.

STUDY DESIGN: Soft tissue-related injuries to the cervical spine structures were produced by use of intact entire human cadavers undergoing rear-end impacts. Radiography, computed tomography, and cryomicrotomy techniques were used to evaluate the injury. OBJECTIVES: To replicate soft tissue injuries resulting from single input of whiplash acceleration to whole human cadavers simulating vehicular rear impacts, and to assess the ability of different modes of imaging to visualize soft tissue cervical lesions. SUMMARY OF BACKGROUND DATA: Whiplash-associated disorders such as headache and neck pain are implicated with soft tissue abnormalities to structures of the cervical spine. To the authors' best knowledge, no previous studies have been conducted to determine whether single cycle whiplash acceleration input to intact entire human cadavers can result in these soft tissue alterations. There is also a scarcity of data on the efficacy of radiography and computed tomography in assessing these injuries. METHODS: Four intact entire human cadavers underwent single whiplash acceleration (3.3 g or 4.5 g) loading by use of a whole-body sled. Pretest and posttest radiographs, computed tomography images, and sequential anatomic sections using a cryomicrotome were obtained to determine the extent of trauma to the cervical spine structures. RESULTS: Routine radiography identified the least number of lesions (one lesion in two specimens). Although computed tomography was more effective (three lesions in two specimens), trauma was not readily apparent to all soft tissues of the cervical spine. Cryomicrotome sections identified structural alterations in all four specimens to lower cervical spine components that included stretch and tear of the ligamentum flavum, anulus disruption, anterior longitudinal ligament rupture, and zygopophysial joint compromise with tear of the capsular ligaments. CONCLUSIONS: These results clearly indicate that a single application of whiplash acceleration pulse can induce soft tissue-related and ligament-related alterations to cervical spine structures. The pathologic changes identified in this study support previous observations from human volunteers observations with regard to the location of whiplash injury and may assist in the explanation of pain arising from this injury. Although computed tomography is a better imaging modality than radiography, subtle but clinically relevant injuries may be left undiagnosed with this technique. The cryomicrotome technique offers a unique procedure to understand and compare soft tissue-related injuries to the cervical anatomy caused by whiplash loading. Recognition of these injuries may advance the general knowledge of the whiplash disorder.

Aged↗
PubMedDate not supplied

High-pressure grease injury of the face.

We describe a rare case of high-pressure grease injury of the face in a 48-year-old man with severe facial edema, soft palate swelling, and bleeding from the nose and mouth. Preoperative computed tomography (CT) revealed multiple low-density areas in nasal cavity, subcutaneous tissue of the cheek, soft palate, right maxillary sinus, and right infratemporal fossa. The patient complained of a dyspnea feeling, and immediate tracheostomy was performed. The grease was removed by the Caldwell-Luc incision approach but was partially left in the infratemporal fossa. After the operation, the patient still complained cheek and temporal pain. CT and magnetic resonance imaging were useful to diagnose the remaining grease, and the remnant of the grease was completely removed by the Weber-Fergusson incision approach.

Face↗
PubMedDate not supplied

Image-guided surgery in resection of benign cervicothoracic spinal tumors: a report of two cases.

BACKGROUND CONTEXT: Osseous spinal tumors are an uncommon cause of persistent axial pain and muscle spasm, but even benign lesions may grow to cause deformity or neurological signs. Traditional treatment approaches to resection can be debilitating even when the tumor is benign. PURPOSE: Emerging technologies allow surgeons to diagnose and treat osseous neoplasms while minimizing the collateral damage caused by surgical exposure and tumor excision. STUDY DESIGN: Technical considerations are presented through two cases of benign osseous neoplasm occurring in the cervicothoracic spine of competitive athletes, demonstrating the meth-ods used to provide effective treatment while maintaining maximal functional capacity. METHODS: Stereotactic imaging and intraoperative guidance was used as an adjunct to tumor care in these patients. Used in combination with minimally invasive, microsurgical techniques,stereotactic guidance localized and verified excision margins of benign vertebral lesions, minimizing soft tissue trauma and collateral damage. RESULTS: Computer-assisted stereotactic localization allowed us to successfully ablate these lesions from their anatomically challenging locations, without disrupting the shoulder girdle or neck musculature, and without extensive bony resection. CONCLUSIONS: Image guidance can accurately localize and guide excision of benign vertebral lesions while minimizing soft tissue trauma and collateral damage, allowing patients a rapid and complete return to high-demand function.

Adolescent↗
PubMed2006

Transversely isotropic properties of porcine liver tissue: experiments and constitutive modelling.

Knowledge of the biomechanical properties of soft tissue, such as liver, is important in modelling computer aided surgical procedures. Liver tissue does not bear mechanical loads, and, in numerical simulation research, is typically assumed to be isotropic. Nevertheless, a typical biological soft tissue is anisotropic. In vitro uniaxial tension and compression experiments were conducted on porcine cylindrical and cubical liver tissue samples respectively assuming a simplistic architecture of liver tissue with its constituent lobule and connective tissues components. With the primary axis perpendicular to the cross sectional surface of samples, the tissue is stiffer with tensile or compressive force in the axial direction compared to that of the transverse direction. At 20% strain, about twice as much force is required to elongate a longitudinal tissue sample than that of a transverse sample. Results of the study suggest that liver tissue is transversely isotropic. A combined strain energy based constitutive equation for transversely isotropic material is proposed. The improved capability of this equation to model the experimental data compared to its previously disclosed isotropic version suggests that the assumption on the fourth invariant in the constitutive equation is probably correct and that anisotropy properties of liver tissue should be considered in surgical simulation.

Animals↗
PubMed1999

Prediction accuracy of soft tissue profile in orthognathic surgery.

The purpose of this study was to compare soft tissue prediction accuracy of model surgery combined with computer software prediction with that of computer software prediction alone and to assess surgical accuracy by comparing the immediate postsurgical cephalogram with the planned movement of skeletal hard tissue. The predicted and actual soft tissue changes and the corresponding skeletal changes of 16 patients were compared using the Quick Ceph Image cephalometric treatment simulation software. A custom analysis was created to measure the hard tissue and soft tissue changes that occurred as a result of the surgical procedure. On average, the predictions were not significantly different from the actual postsurgical profile changes. Surgical changes of hard tissues from presurgery to postsurgery were accurate as planned except for the position of N-ANS. All lower soft tissue points moved significantly during treatment. Quick Ceph Image offers a rapid and reliable method of profile prediction that does not require artistic skill. If predictions are interpreted with caution and transferred accurately to the model surgery, they can provide an excellent visual aid during presurgical treatment planning and patient presentation.

Adolescent↗
PubMed1990

Fluid-fluid level: a nonspecific finding in tumors of bone and soft tissue.

Fluid-fluid levels have commonly been reported to occur in aneurysmal bone cysts but have also been seen in telangiectatic osteosarcoma, chondroblastoma, and giant cell tumor of bone. The authors reviewed their experience with nine bone and three soft-tissue tumors that showed fluid-fluid levels on computed tomographic or magnetic resonance images. The bone tumors included fibrous dysplasia, simple bone cyst, recurrent malignant fibrous histiocytoma of bone, two classical osteosarcomas, and four aneurysmal bone cysts. The soft-tissue tumors included soft-tissue hemangioma and two synovial sarcomas. Except for aneurysmal bone cysts, these types of tumors have not been reported to be associated with fluid-fluid levels. Radiologic-pathologic correlation was available in seven patients; in all seven, the fluid-fluid levels indicated prior hemorrhage. The authors conclude that the presence of fluid-fluid levels in bone or soft-tissue tumors cannot be considered diagnostic of any particular tumor.

Adolescent↗
PubMed1988

Necrotizing otitis externa due to Aspergillus in an immunocompetent patient.

An 85-year-old, nondiabetic man is described with necrotizing (malignant) otitis externa. The patient developed facial nerve paralysis in the presence of a progressive cellulitis and chondritis of the external auditory meatus. Destruction of the bony meatus and mastoid and obliteration of normal soft-tissue planes at the skull base were documented by computed tomographic scans. Aspergillus fumigatus was isolated from the external meatus and deep tissue specimens. Fungal invasion of bone and soft tissue was confirmed histopathologically. Pseudomonas aeruginosa was never isolated. This case is unusual from both the standpoint of etiology and host susceptibility in that the patient had no apparent underlying disease. Amphotericin B and rifampin therapy following radical mastoidectomy halted the progression of disease. Finally, this case illustrates the pitfalls of empiric antibacterial therapy for necrotizing otitis externa without cultural confirmation of the etiologic agent.

Aged↗
PubMed2002

Longitudinal investigation of soft palate and nasopharyngeal airway relations in different rotation types.

The relationship between the soft palate and the nasopharyngeal airway in different mandibular growth rotation models was investigated. A total of 72 lateral cephalograms were obtained three years longitudinally from 24 individuals. The subjects had a mean age of 10.7 +/- 1.2 years and showed a normal (n = 8), posterior (n = 8), and anterior (n = 8) mandibular rotation pattern. Linear and angular measurements of the soft palate and nasopharyngeal airway were recorded by using PORDIOS computer program and were examined by means of descriptive statistics and paired t-tests. A linear increase in the soft palate length (SPL) was observed in all groups, with the posterior mandibular rotation group showing the largest increase within the observation period (28.56 +/- 4.83 to 34.98 +/- 2.87; P < .01). According to the paired t-test, palatal plane (ANS-PNS)/soft palate tip (SPT) angle showed a statistically significant decrease in the posterior rotation group (P < .01). The ratio between SPL and superior nasopharyngeal space (SPS) did not show a statistically significant difference among the groups. Although various amounts of soft palate and nasopharyngeal airway growth occurred in the different mandibular rotation types, the ratio between SPL and SPS (SPL/SPS), which plays an indispensable role in velopharyngeal functions, did not show a statistically significant difference in the groups. This assured velopharyngeal closure throughout the active growth period.

Cephalometry↗
PubMedDate not supplied

Lateral disk herniation into the lumbar intervertebral foramen: differential diagnosis.

Lateral disk herniation into the intervertebral foramen if not recognized may result in a negative surgical exploration. The condition is readily recognized by computed tomography (CT), which demonstrates a soft-tissue mass in the intervertebral foramen, focal protrusion of the posterolateral margin of the disk into the foramen, absence of dural sac deformity, and occasionally the presence of calcium or gas in the intervertebral foramen. The differential diagnosis includes metastatic neoplasm, primary neoplasm, and conjoined root sheath anomaly. Features that enable CT differentiation of these conditions from lateral disk herniation are described. Myelography is useful in the identification of a conjoined root sheath.

Diagnosis, Differential↗