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At least 433 records · Page 24Linked to original sources

PubMed1999

Fabricating auricular prostheses using three-dimensional soft tissue models.

This article describes a method for fabricating an auricular prosthesis. This procedure uses the contours of the soft tissue surface from computerized tomography scans to fabricate a computer-generated, side-inverted 3-dimensional soft tissue model from a solid block of polyurethane using an Endoplan milling machine. The resultant 3-dimensional soft tissue model can then be used as the basis for a wax sculpture. This procedure facilitates the planning of the prosthesis; symmetrical modeling, especially for large, hemifacial defects; and the impression, which can be made on the model itself.

Acrylic Resins↗

PubMed1985

Radiology and pathology of malignant fibrous histiocytomas of the soft tissues: a report of ten cases.

Malignant fibrous histiocytomas (MFH) are believed to originate from histiocytes and are composed of malignant cells with spindle or round shapes. We evaluated ten MFH of the soft tissues by plain roentgenograms, computed tomography (CT), and angiography and subdivided them into four grades of anaplasia and five predominant histologic variants. The variants of MFH demonstrated different vascular patterns. The extension of the lesions could be determined by CT and angiography. CT is the method of choice in the assessment of size and extent of MFH of the soft tissues. When intra-arterial chemotherapy is indicated the angiograms obtained at each catheter placement may substitute CT in follow-up studies obviating additional diagnostic procedures.

Adult↗

PubMed1993

Reliability and validity of imaging diagnosis of temporomandibular joint disorder.

The purpose of this article is to review reliability and validity of imaging diagnosis of temporomandibular joint disorders. Plain-film and tomography are basic imaging techniques for assessment of the temporomandibular joint. These can be used for evaluation of osseous disease and as a baseline for follow-up. In patients with symptoms from the joint, plain-film and tomography are rarely definitive, and evaluation of the soft tissues is frequently necessary. Arthrography, computed tomography, and magnetic resonance imaging have all been used for evaluation of the soft-tissue components of the joints. Accuracy studies of these techniques have demonstrated the highest diagnostic accuracy for magnetic resonance imaging. Arthrography is relatively insensitive for detection of medial and lateral displacements. Magnetic resonance imaging accurately depicts both hard and soft tissues, and this technique is emerging as the prime diagnostic imaging technique in patients presenting with clinical signs and symptoms of a disorder of the temporomandibular joint. The most frequent findings when patients with clinical symptoms of temporomandibular joint disorders are "imaged" are different forms of disc displacement and degenerative joint disease. Studies have demonstrated a high prevalence of different forms of disc displacement in patients, although these abnormalities are also seen in some asymptomatic volunteers. Future research should further refine imaging techniques to come closer to an understanding of the association between morphologic alterations and patient symptoms.

Arthrography↗

PubMed2005

Facial soft tissue injuries as an aid to ordering a combination head and facial computed tomography in trauma patients.

PURPOSE: While the trauma computed tomography (CT) head scan is frequently ordered during resuscitation of multiply injured patients, determining when also to order facial CT in these situations can be difficult. Consequently, facial fractures are commonly missed on initial imaging evaluation. In acute trauma situations, facial soft tissue injury markers are often used to aid in this decision. A study was undertaken to identify exactly which facial soft tissue injuries correlate with facial fractures and which did not. The aim of our research was to compare the facial soft tissue injury patterns of patients receiving a combination head and facial CT who had facial fractures versus those who had no facial fractures. PATIENTS AND METHODS: A retrospective trauma registry review was performed for a 5-year period at Legacy Emanuel Hospital, a level 1 trauma center. The trauma team saw a total of 9,871 trauma patients and 49.9% required head CT as part of their initial evaluation. A total of 777 (15.7%) patients had a combination head and facial CT in which 477 (61.4%) had a facial fracture and 300 (38.6%) had no facial fracture. Statistical significance was established using Bonferroni corrected P values less than .05. RESULTS: Lacerations occurring in areas of the lips, nose, and intraorally, as well as wounds leading to periorbital contusion and subconjunctival hemorrhage, were significantly prevalent in the fracture group. Conversely, scalp lacerations and scalp contusions were significantly higher in the nonfracture group. Other injuries such as lacerations of the tongue, chin, forehead, cheek, ear, eyelid, and eyebrow were indistinguishable between both groups. CONCLUSIONS: Our data demonstrate that there are certain facial soft tissue injury zones that correlate with facial fractures in trauma patients who obtain head CT. We would like to propose that the acronym LIPS-N (Lip laceration, Intraoral laceration, Periorbital contusion, Subconjunctival hemorrhage, and Nasal laceration) be used in conjunction with a physical examination when assessing if a trauma patient who is getting head CT should also get facial CT.

Abbreviations as Topic↗

PubMed2004

Myxoid liposarcoma with adipocytic maturation: detection of TLS/CHOP fusion gene transcript.

This report describes a 49-year-old woman with a well-circumscribed nodule of liposarcoma. The patient noticed a soft, slowly growing mass at the right sural region. Both axial computed tomography and magnetic resonance imaging revealed a soft tissue tumor consisting of nonfatty lesion measuring 5 x 3 x 3 cm circumscribed by a 1-cm thickened fatty area. Histologically, the tumor was made of 2 distinct components: the inner component of the tumor was a classic myxoid liposarcoma with numerous lipoblasts; the outer component was a lipoma-like lesion consisting of mature adipocytes without atypical nuclei. Immunohistochemically, MDM2 overexpression was observed and p53 immunophenotype was negative in both components. Molecular analysis revealed that type 1 TLS/ CHOP fusion gene transcript, characteristic of myxoid/round cell liposarcoma, was detected in both areas.

Adipocytes↗

PubMed1998

Force interactions in laparoscopic simulations: haptic rendering of soft tissues.

Research in the area of computer assisted surgery and surgical simulation has mainly focused on developing 3D geometrical models of the human body from 2D medical images, visualization of internal structures for educational and preoperative surgical planning purposes, and graphical display of soft tissue behavior in real time. Conveying to the surgeon the touch and force sensations with the use of haptic interfaces has not been investigated in detail. We have developed a set of haptic rendering algorithms for simulating "surgical instrument--soft tissue" interactions. Although the focus of the study is the development of algorithms for simulation of laparoscopic procedures, the developed techniques are also useful in simulating other medical procedures involving touch and feel of soft tissues. The proposed force-reflecting soft tissue models are in various fidelities and have been developed to simulate the behavior of elastically deformable objects in virtual environments. The developed algorithms deal directly with geometry of anatomical organs, surface and compliance characteristics of tissues, and the estimation of appropriate reaction forces to convey to the user a feeling of touch and force sensations.

Algorithms↗

PubMed1984

Computed tomography of synovial sarcoma of the foot.

We report two patients with synovial sarcoma of the foot. Both presented with a soft-tissue mass that exhibited calcification. Although the radiologic findings are non-specific, the presence of foci of calcification within the soft-tissue mass is suggestive of synovial sarcoma. Computed tomography shows the extent of the mass, soft-tissue calcification and bone destruction thus helping in earlier detection and more accurate staging.

Calcinosis↗

PubMed2002

Imaging of soft-tissue myxoma with emphasis on CT and MR and comparison of radiologic and pathologic findings.

PURPOSE: To determine the imaging characteristics of soft-tissue myxoma, with emphasis on computed tomographic (CT) and magnetic resonance (MR) imaging findings and pathologic comparison. MATERIALS AND METHODS: Records of 45 pathologically confirmed soft-tissue myxomas in 44 patients were retrospectively reviewed. Patient demographics and radiographs (n = 20), bone scintigrams (n = 2), angiograms (n = 3), and ultrasonographic (US) (n = 6), CT (n = 14), and MR images (n = 33) were evaluated by two musculoskeletal radiologists with agreement by consensus for lesion location, lesion size, and intrinsic characteristics. RESULTS: Soft-tissue myxoma more commonly affected women (59%; average age 52 years) and manifested as a slowly enlarging (64%) painful (51%) mass. Lesions were most frequently intramuscular (82%) and involved the thigh (51%). An appearance similar to that of a cyst was seen at CT (at which the lesions demonstrated low attenuation) and at MR imaging (at which the lesions demonstrated markedly high signal intensity on T2-weighted images) in all cases because of the high water content of mucin that was seen histologically. The true solid architecture of these lesions was best depicted in all cases at US (at which the lesions were hypoechoic, not anechoic) and on MR images obtained with contrast material (at which the lesions demonstrated internal enhancement). A small amount of tissue similar to fat surrounding these intramuscular myxomas (71% at MR imaging) corresponded histologically (70%) to atrophy of surrounding muscle. CONCLUSION: Soft-tissue myxoma often demonstrates characteristic US, CT, and MR imaging findings, including intramuscular location, intrinsic high water content, and a surrounding rim of fat.

Adolescent↗

PubMed1998

Multilevel and motion model-based ultrasonic speckle tracking algorithms.

A multilevel motion model-based approach to ultrasonic speckle tracking has been developed that addresses the inherent trade-offs associated with traditional single-level block matching (SLBM) methods. The multilevel block matching (MLBM) algorithm uses variable matching block and search window sizes in a coarse-to-fine scheme, preserving the relative immunity to noise associated with the use of a large matching block while preserving the motion field detail associated with the use of a small matching block. To decrease further the sensitivity of the multilevel approach to noise, speckle decorrelation and false matches, a smooth motion model-based block matching (SMBM) algorithm has been implemented that takes into account the spatial inertia of soft tissue elements. The new algorithms were compared to SLBM through a series of experiments involving manual translation of soft tissue phantoms, motion field computer simulations of rotation, compression and shear deformation, and an experiment involving contraction of human forearm muscles. Measures of tracking accuracy included mean squared tracking error, peak signal-to-noise ratio (PSNR) and blinded observations of optical flow. Measures of tracking efficiency included the number of sum squared difference calculations and the computation time. In the phantom translation experiments, the SMBM algorithm successfully matched the accuracy of SLBM using both large and small matching blocks while significantly reducing the number of computations and computation time when a large matching block was used. For the computer simulations, SMBM yielded better tracking accuracies and spatial resolution when compared with SLBM using a large matching block. For the muscle experiment, SMBM outperformed SLBM both in terms of PSNR and observations of optical flow. We believe that the smooth motion model-based MLBM approach represents a meaningful development in ultrasonic soft tissue motion measurement.

Algorithms↗

PubMed1994

Computed tomographic follow-up study of 21 cases of nonoperatively treated cervical intervertebral soft disc herniation.

The authors studied the natural evolution of cervical soft disc herniations in 21 patients with cervical radiculopathy that was successfully treated with conservative therapy only. The first computed tomography (CT) examination was performed during the acute phase of the radiculopathy, and the second performed from 1 to 30 months after healing. The initial CT allowed classification of the herniations according to size: nine were considered small, seven medium, and five large. Comparison with follow-up scans showed that five of the herniations decreased between 0 and 35%, six decreased between 35 and 75% and ten decreased between 75 and 100%. The largest herniations were those that had the greatest tendency to decrease in size. This tendency could be secondary to the herniation breaking through the outer fibers of the anulus and entering the epidural space.

Adult↗

PubMed1982

Computed tomography of fibrous dysplasia.

Skeletal fibrous dysplasia produces changes that are usually readily recognized on plain radiographs. Occasionally, routine radiography may not demonstrate the characteristic appearance of the disease. The density of abnormal bone in craniofacial fibrous dysplasia may preclude adequate assessment of areas where soft-tissue impingement may occur. Computed tomography (CT) is useful in demonstrating the amorphous "ground-glass" texture of the lesion and in defining the extent of craniofacial disease including impingement upon orbital structures. CT was useful in five patients with fibrous dysplasia in whom the nature or extent of involvement was not entirely clear.

Adult↗

PubMed1995

Cephalometric and computed tomographic predictors of obstructive sleep apnea severity.

The interaction between craniofacial structure assessed by lateral cephalometry, and tongue, soft palate, and upper airway size determined from computed tomography (CT) scans was examined in 25 control subjects and 80 patients with obstructive sleep apnea (OSA). On the basis of the cephalometric analyses, the patients with OSA had retruded mandibles with larger ANB angle differences, elongated maxillary and mandibular incisors and mandibular molars, and high total upper and lower face heights The computed tomographic evaluations revealed that patients with OSA also had larger tongue, soft palate, and upper airway volumes. Men with OSA and skeletal Class I malocclusions had significantly larger soft palates than comparable controls. Both tongue and soft palate volumes were positively correlated with body mass index. A principal component analysis reduced the database, and one significant correlation was identified. Subjects with high total, upper and lower face heights, elongated maxillary and mandibular teeth, and proclined lower incisors were observed to have large tongue, soft palate, and upper airway volumes, to have a higher apnea index and to be obese. Linear regression analysis indicated that a high apnea index was seen in association with large tongue and soft palate volumes, a retrognathic mandible, an anteroposterior discrepancy between the maxilla and mandible, an open bite tendency between the incisors, and obesity.

Adult↗

PubMedDate not supplied

[Quantitative evaluation of the effectiveness of radiotherapy].

The paper proposes a procedure for processing computed tomograms, which records changes in the density and size of the tissue portion exposed to radiation within the preset cross section of layers. Examples of management of 4 patients with various tumorous processes on radiation therapy are presented. The procedure of computed diagnostic processing of computed tomograms gives rather new quantitative information on the changes occurring in the pathological focus and its adjacent healthy tissues, which may lead to the efficiency of radiation therapy.

Evaluation Studies as Topic↗

PubMed2000

Transient mediastinal enlargement: an unusual computed tomographic manifestation of pulmonary venous hypertension and congestive heart failure.

We describe a case of diffuse superior and middle mediastinal enlargement of soft tissue attenuation noted on helical computed tomography (CT) of a patient with clinical and radiographic findings of congestive heart failure (CHF). Upon treatment and improvement of his pulmonary venous hypertension, a repeat CT scan revealed resolution of the mediastinal abnormalities. We, therefore, advocate a search for primary CT signs of CHF in patients with findings of widespread mediastinal distension. If present, repeat CT scanning after resolution of the cardiac condition should be performed before further intervention for the mediastinal abnormality is attempted.

Heart Failure↗

PubMed2003

Primary subcutaneous cyst hydatic disease in proximal thigh: an unusual localisation: a case report.

BACKGROUND: Musculoskeletal hydatidosis is very rare and represents 1%-5.4% of all cases of echinococcosis. On clinical basis, infection mimics a soft-tissue tumor, and the preoperative radiological diagnosis is very important to avoid biopsy. CASE PRESENTATION: We report an unusual case of primary subcutaneous hydatidosis in proximity to vastus lateralis muscle. It was diagnosed according to the computed tomography appearance, clinical and pathological findings. A 43 year old female patient was admitted with a history of pain at proximal thigh for the last 30 days. On physical examination, a mass which was 4 x 5 cm in diameter, painful and erythematous, was palpated over greater trochanter. Sedimentation rate was 40 mm in the first hour. CT (Computed Tomography) scan demonstrated, a soft tissue mass with central cystic component in the subcutaneous tissue near vastus lateralis muscle. Histopathological examination of the specimen revealed a pericystic structure, which consisted of connective tissue and scattered hyaline cells showing a necrotic basophilic structure that resembled a cuticular membrane. Treatment with high dose albendazole was conducted for 4 weeks. CONCLUSIONS: This case illustrates that echinococcal disease should be considered in the differential diagnosis of every cystic mass in every anatomic location, especially when they occur in areas where the disease is endemic.

Adult↗

PubMed2000

Spectrum of complications related to secondary hyperparathyroidism in a peritoneal dialysis patient.

The index patient is a 23-year-old female with end-stage renal disease (ESRD) secondary to chemotherapeutic agents. Continuous cycling peritoneal dialysis (CCPD) has been the renal replacement therapy for the past 5 years since a failed cadaveric renal transplant. Past medical history was significant for diabetes mellitus, hypertension, anemia, bilateral subclavian vein thrombosis with superior vena cava syndrome, secondary hyperparathyroidism, leukemia (at age 8), and hyperlipidemia. On presentation, soft tissue nodules were noted in the anterolateral surfaces of the legs. After 3 months of continued low-calcium-dialysate CCPD, calcitriol, and oral phosphate binders, a 2 x 3 cm nodule was noted on the posterior aspect of the thorax at the scapula. The only complaint at this time was shoulder pain at the acromioclavicular joint. Radiological examination revealed a 3 x 4 cm soft tissue opacity in the superior segment of the left lower lobe laterally. Despite a prior subtotal parathyroidectomy, phosphate binders, and calcitriol, the parathyroid hormone levels continued to increase, with development of tumoral calcinosis, worsening renal osteodystrophy, and calciphylaxis. Computed tomography examination revealed extensive soft tissue calcification consistent with tumoral calcinosis. An ulcerative lesion (1 cm) developed on the lateral aspect of the upper thigh owing to warfarin necrosis versus calciphylaxis. At this time, the phosphate binder was changed from calcium acetate to sevelamer hydrochloride. Aggressive wound treatment and aggressive calcium and phosphate control added to the treatment regimen has resulted in healing of the single ulcer and a decrease in the size of the tumoral lesions. In conclusion, early recognition and aggressive treatment of calciphylaxis can result in reduced morbidity and mortality from calciphylaxis in ESRD patients.

Adult↗

PubMed2005

Primary extradural epithelioid leiomyosarcoma of the cervical spine: case report and literature review.

OBJECTIVE AND IMPORTANCE: No case of primary epithelioid leiomyosarcoma involving the spine has been reported previously. CLINICAL PRESENTATION: A 61-year-old Nigerian woman presented with progressive spastic quadriparesis and acute urinary retention. Her only medical history included a total abdominal hysterectomy for fibroids 10 years earlier in Nigeria. Results of the general examination were normal. Pyramidal spastic quadriparesis (3/5) with a sensory level at C5-C6 was found neurologically. Magnetic resonance imaging scans of the brain and spine revealed extradural cord compression at C3-C5 as the sole abnormality. This was caused by a large, soft tissue mass arising from the erector spinae muscles, which was predominantly isointense on T1-weighted images, of mixed intensity on T2-weighted images, and homogenously enhanced after gadolinium contrast agent administration. There was an associated signal change in the cord at C3-C4. Computed tomography confirmed the predominantly soft tissue involvement, but with bone erosion and infiltration within the posterior elements of C4. Systemic screening for cancer was negative. INTERVENTION: At decompressive laminectomy, urgently undertaken under corticosteroid cover, an excessively vascularized, soft tissue tumor was subtotally excised, after which independent walking and normal sphincter function were regained within 1 week. Four weeks later, a complete macroscopic tumor excision was undertaken, incorporating lateral mass (C3-C6) and C2 pedicle screw stabilization, along with iliac crest bone grafting. The patient's neurological status continued to improve. However, while awaiting radical radiotherapy, the patient declined further treatment and returned to her native Nigeria. Histopathological findings were consistent with an epithelioid leiomyosarcoma. CONCLUSION: This is the first reported case of a primary craniospinal epithelioid leiomyosarcoma.

Actins↗

PubMed2006

Investigation of optimal method for inducing harmonic motion in tissue using a linear ultrasound phased array--a simulation study.

Many noninvasive ultrasound techniques have been developed to explore mechanical properties of soft tissues. One of these methods, Localized Harmonic Motion Imaging (LHMI), has been proposed to be used for ultrasound surgery monitoring. In LHMI, dynamic ultrasound radiation-force stimulation induces displacements in a target that can be measured using pulse-echo imaging and used to estimate the elastic properties of the target. In this initial, simulation study, the use of a one-dimensional phased array is explored for the induction of the tissue motion. The study compares three different dual-frequency and amplitude-modulated single-frequency methods for the inducing tissue motion. Simulations were computed in a homogeneous soft-tissue volume. The Rayleigh integral was used in the simulations of the ultrasound fields and the tissue displacements were computed using a finite-element method (FEM). The simulations showed that amplitude-modulated sonication using a single frequency produced the largest vibration amplitude of the target tissue. These simulations demonstrate that the properties of the tissue motion are highly dependent on the sonication method and that it is important to consider the full three-dimensional distribution of the ultrasound field for controlling the induction of tissue motion.

Acoustics↗