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PubMed1984

Role of radiologic imaging in management planning of giant cell tumor of bone.

The radiologic studies of 24 patients with giant cell tumors were evaluated with respect to their ability to determine tumor extent and to influence management. Computed tomography (CT) was the most accurate method for detecting soft tissue tumor extension, and conventional tomography was the best technique for evaluating penetration of subarticular cortical bone. Detection of these findings led to performance of en bloc tumor resection rather than curettage and grafting in patients with lower extremity tumors. Arthrotomography was helpful in some instances in detecting cartilage and joint invasion by tumor, joint invasion being an indication for extra-articular rather than transarticular tumor resection. Scintigraphy was not as accurate as conventional tomography or CT in determining intraosseous tumor extent because of increased tracer uptake beyond the true tumor limits in several cases. Angiography has been largely replaced by CT in evaluating giant cell tumors.

Adolescent↗
PubMedDate not supplied

Gonadotropin-secreting pituitary tumor associated with hypersecretion of testosterone and hypogonadism after hypophysectomy.

OBJECTIVE: To review gonadotropin-secreting pituitary tumors and report the rare case of one of these tumors that caused high serum testosterone concentrations, followed by hypogonadism after hypophysectomy. METHODS: A case report is presented of a 61-year-old man who had decreased vision in his left eye, found by computed tomography of the sella to be attributable to a soft tissue pituitary mass with upward extension that caused elevation and deviation of the optic chiasm. Endocrine and pathologic evaluations are presented, and the treatment and follow-up course are discussed. RESULTS: Endocrine evaluation revealed a serum follicle-stimulating hormone (FSH) of 72.48 mIU/mL, luteinizing hormone (LH) of 31.65 mIU/mL, prolactin of 26.42 ng/mL, and total testosterone of 15.24 ng/mL (all values higher than the normal ranges). A soft tissue mass (3.2 by 2.5 by 1.2 cm) with negative immunocytochemical staining for prolactin and growth hormone but positive staining for synaptophysin, FSH, and LH was removed. One month postoperatively, the patient's chief complaints were a decrease in penile size and erectile dysfunction. Endocrine evaluation revealed a decreased LH of <0.3 mIU/mL, total testosterone of <0.2 ng/mL, and FSH of 4.3 mIU/mL. Three months later with testosterone replacement therapy, testosterone levels normalized, LH was <0.3 mIU/mL, and FSH was 3.9 mIU/mL. Thyroid function and adrenal function were normal before and after surgical intervention. CONCLUSION: This rare case indicates that gonadotropin tumors can produce a functional LH that can increase serum testosterone levels.

Follicle Stimulating Hormone↗
PubMed1984

Observations on computerized quantitative bone scintigraphy in renal osteodystrophy.

Skeletal radiotracer (99mTc-HEDP) uptake was quantitated with and without the aid of a computer in 30 chronic dialysis patients with histologic evidence of renal osteodystrophy. Before scintigraphy, elevated soft-tissue activity due to the absence of renal radiotracer excretion was reduced by hemodialysis. The results were compared with those of a normal group and with the results of the biochemical and the bone morphometric studies of these patients. In all patients the radiotracer uptake was elevated, often markedly. In several patients with minimal histologic bone disease, however, soft-tissue activity could not be normalized by hemodialysis although its influence on the quantitative data could be further reduced (but not excluded) by computer evaluation of skeletal radiotracer uptake. Since the latter technique clearly distinguished the majority of the patients from the normals, it appears that computerized quantitative skeletal analysis is a potentially accurate scintigraphic method for detecting renal osteodystrophy. The significant relationship between skeletal radiotracer uptake, in particular at the bone biopsy site, and only the histologic features of increased bone turnover suggest that hyperparathyroidism is the major cause of this increased tracer uptake in renal osteodystrophy.

Adolescent↗
PubMed2004

Measuring of viscoelastic properties of homogeneous soft solid using transient elastography: an inverse problem approach.

Two main questions are at the center of this paper. The first one concerns the choice of a rheological model in the frequency range of transient elastography, sonoelasticity or NMR elastography for soft solids (20-1000 Hz). Transient elastography experiments based on plane shear waves that propagate in an Agar-gelatin phantom or in bovine muscles enable one to quantify their viscoelastic properties. The comparison of these experimental results to the prediction of the two simplest rheological models indicate clearly that Voigt's model is the better. The second question studied in the paper deals with the feasibility of quantitative viscosity mapping using inverse problem algorithm. In the ideal situation where plane shear waves propagate in a sample, a simple inverse problem based on the Helmholtz equation correctly retrieves both elasticity and viscosity. In a more realistic situation with nonplane shear waves, this simple approach fails. Nevertheless, it is shown that quantitative viscosity mapping is still possible if one uses an appropriate inverse problem that fully takes into account diffraction in solids.

Algorithms↗
PubMed1999

Soft cervical disc herniation. Influence of cervical spinal canal measurements on development of neurologic symptoms.

STUDY DESIGN: In 100 consecutive patients who underwent surgery because of soft cervical disc herniation, the sagittal and transverse diameters, the area of the bony cervical spinal canal, the sagittal diameter of the hernia, and the minimal bony intervertebral foramen diameter were measured by computed tomography. The data were compared with measurements from a control group of 35 matched healthy individuals. OBJECTIVES: To evaluate the relation between the severity of concurrent neurologic symptoms and the sagittal and transverse diameters, the cross-sectional area of the bony spinal canal, the sagittal diameter of the hernia, and diameter of the minimal bony intervertebral foramen in patients with soft cervical disc herniation. SUMMARY OF BACKGROUND DATA: Traumatic injury and spondylotic changes have a far greater impact on the spinal cord and nerve roots if the sagittal diameter of the bony cervical spinal canal is small. However, in the case of soft cervical disc herniation, no computer tomographic measurements are available for sagittal and transverse diameters, cross-sectional area of the bony spinal canal, sagittal diameter of the hernia, and diameter of the minimal bony intervertebral foramen in relation to the severity of concurrent neurologic symptoms. METHODS: Computed tomography was used to measure sagittal and transverse diameters, cross-sectional area of the bony cervical spinal canal, sagittal diameter of the hernia, and diameter of the minimal bony intervertebral foramen in 100 patients with symptomatic monosegmental cervical soft disc herniation. All patients had undergone an anterior discectomy with removal of the hernia and subsequent interbody fusion using an autologous bone graft taken from the iliac crest. RESULTS: A mean sagittal diameter of the bony cervical spinal canal of 12.9 mm was found, indicating a certain degree of developmental stenosis. Patients with motor disturbances had a significantly smaller sagittal diameter of the bony spinal canal than did patients without motor disturbances. There was a linear correlation between the sagittal diameter of the bony cervical spinal canal and that of the hernia. The sagittal diameter, the area of the bony spinal canal, and diameter of the minimal bony intervertebral foramen were significantly smaller in patients with soft cervical disc herniation than in the control group. CONCLUSIONS: Results from this study strongly suggest that the degree and severity of neurologic symptoms accompanying cervical soft disc herniation are inversely related to the sagittal diameter and the area of the bony cervical spinal canal. The latter area is reduced in cases of developmental stenosis or because of soft disc herniation. Moreover, patients with soft cervical disc herniation have a significantly smaller sagittal diameter of the bony spinal canal, a significantly smaller minimal bony intervertebral foramen diameter, and a significantly smaller cross-sectional area of the bony cervical canal than do healthy matched individuals.

Cervical Vertebrae↗
PubMed1993

Computed tomography, magnetic resonance imaging, and electromyographic studies of tensor veli palatini muscles in patients with nasopharyngeal carcinoma.

One of the factors that induces eustachian tube dysfunction caused by the invasion of nasopharyngeal carcinoma is paralysis of the tensor veli palatini muscle. Electromyography (EMG), computed tomography (CT), and/or magnetic resonance imaging (MRI) were used to study the tensor muscle and the related paratubal structures and parapharyngeal space. This study, from 44 patients with nasopharyngeal carcinoma, showed that 67% of tensor muscles on the side of the symptomatic ear yielded abnormal electromyographic waveforms, which usually indicated a neurogenic disorder. In the majority of the abnormal EMG cases, CT or MRI often revealed that the pharyngobasilar fascia and the tensor muscle were compressed anterolaterally and the upper prestyloid parapharyngeal space was infiltrated. It was found that an abnormal electromyogram of the tensor muscle generally suggested a more advanced T stage and eustachian tube dysfunction. Otitis media with effusion in the stage I cases was usually not caused by paralysis of the tensor muscle. The invasion of some early cancers, especially localized on the torus tubarius, could also cause the effusion.

Adolescent↗
PubMed1989

[Arteriography, lymphography, gammagraphy and computer tomography in the diagnosis of musculoskeletal tumors].

The authors emphasize the importance of early and exact diagnosis of musculoskeletal tumours of the extremities and spine. This aim cannot be achieved by common biochemical, haematological and X-ray examinations. Therefore the authors recommend to use already during the initial examination of the patient a combination of classical roentgenography, arteriography, possibly lymphography, gammagraphy and computed tomography. The authors present a detailed account of experience with the application of the above diagnostic methods in 146 patients. On arteriograms of 37 patients dislocated main arteries were found 16 times, blood lakes 20 times. Lymphography revealed metastatic affection of regional lymph nodes in 21% of all patients, most frequently in bone reticulosarcoma and in synovial sarcoma. All-body gammagraphy helped to make the localization and assessment of size of the tumour more accurate, in two-thirds of the patients it was larger when visualized by this method than on native roentgenograms. In 3 of 14 Ewing sarcomas all-body gammagraphy revealed a polyostotic localization of the tumour. Computed tomography revealed the extent of infiltration and destruction of bone and soft tissues in pelvic and spinal tumours.

Adolescent↗
PubMed1998

Numerical solution of the multidimensional freezing problem during cryosurgery.

A multidimensional, finite difference numerical scheme for the freezing process of biological tissues during cryosurgery is presented, which is a modification of an earlier numerical solution for inanimate materials. The tissues are treated as nonideal materials, freezing over a temperature range and possessing temperature-dependent thermophysical properties, blood perfusion, and metabolic heat generation. The numerical scheme is based on the application of an effective specific heat, substituting the intrinsic property, to include the latent heat effect within the phase transition temperature range. Results of the numerical solution were verified against an existing exact solution of a one-dimensional inverse Stefan problem in Cartesian coordinates. Results were further validated against experimental data available from the literature. The utility of the numerical solution for the design and application of cryodevices is demonstrated by parametric studies of the freezing processes around spherical and cylindrical cryoprobes. The parameters studied are the cryoprobe cooling power and the dimensions of the frozen region. Results are calculated for typical thermophysical properties of soft biological tissues, for angioma and for water.

Cell Survival↗
PubMed1994

The role of magnetic resonance imaging in the diagnosis of soft tissue lesions.

Over the last decade MR imaging has gained widespread acceptance as the modality of choice for initial evaluation of a soft tissue mass. Although MR imaging generally does not predict the histologic nature of a mass, significant data are accumulating on MR imaging features useful in the diagnosis of several benign conditions and a few malignant ones. Soft tissue masses that do not demonstrate tumor-specific features on MR imaging should be considered indeterminate and possibly malignant and a biopsy should be obtained. This article reviews the literature and elaborates on soft tissue conditions where MR imaging features can suggest an accurate diagnosis of a soft tissue mass. The article also reviews other important applications of MR imaging as well as recent developments in pulsing sequences and MR spectroscopy. The major series studying the diagnostic value of MR imaging in soft tissue masses is discussed and compared.

Connective Tissue Diseases↗
PubMed1993

Primary T-cell immunoblastic lymphoma of the orbit in a pediatric patient.

BACKGROUND: The authors report a case of an 8-year-old pediatric patient with a 2-week history of painless periorbital swelling unresponsive to antibiotic treatment. METHODS: Computed tomography (CT) showed a large, lateral, anterior left orbital soft tissue mass with bony erosion into the anterior cranial fossa through the roof of the orbit laterally. Surgical exploration showed a hard white mass that had eroded through the roof of the left orbit and into the anterior cranial fossa, with herniation of the brain and associated dura through the defect. Results of a complete evaluation of the child for systemic lymphoma, including a lumbar puncture, chest x-ray, bone scan, bone marrow aspirate, and chest/abdomen CT, were negative. RESULTS: Results of histopathologic and immuno-histochemical evaluation showed a primary orbital T-cell immunoblastic lymphoma. The patient was treated with intrathecal ara-C (Cytosar-U) and methotrexate, 16.2 Gy of whole brain irradiation, and a chemotherapeutic protocol consisting of cyclophosphamide (Cytoxin), vincristine (Oncovin), methotrexate, daunomycin, and prednisone. The patient remains free of lymphoma 33 months after diagnosis, with 20/20 visual acuity in both eyes. CONCLUSION: The authors believe that this is the youngest documented case of a primary T-cell immunoblastic lymphoma of the orbit.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2003

Plantar soft tissue loading under the medial metatarsals in the standing diabetic foot.

Diabetes mellitus (type 2) is the most frequent cause of non-traumatic lower-limb amputations. The major cause of impairment to the feet of diabetics is persistent hyperglycemia, potentially leading to peripheral neuropathy as well as to pathological changes in plantar soft tissue, which stiffen its structure and diminish its ability to effectively distribute foot-ground contact loads. In this study, a computational model of the foot structure in the standing position was utilized to evaluate stress distributions in plantar soft tissue under the medial metatarsal heads of simulated diabetic versus normal feet. The model comprises five anatomic planar cross-sections in the directions of the foot rays, which were solved for internal stresses under static ankle joint reaction (300 N) and triceps surae muscle forces (150 N) using the finite element method. Tissues were assumed to be homogenous, isotropic and elastic materials, with nonlinear stress-strain relations for the ligaments, fascia and plantar tissue. The model revealed significant tension stress concentrations (90-150 KPa) in the plantar pad of the simulated diabetic forefoot: they were four times the normal maximum stress under the first metatarsal head and almost eight times the normal maximum stress under the second metatarsal head. It was shown that with increased severity of stiffening of the plantar pad, as related to glucose-exposure, peak forefoot contact stresses may rise by 38 and 50% under the first and second metatarsal heads, respectively. The increase in averaged (von Mises) internal stresses within the plantar soft tissue is even more pronounced, and may rise by 82 and 307% for the tissue under the first and second metatarsal heads, respectively. These results, which conform to experimental data gathered over the last two decades, suggest that the process of injury in diabetic feet is very likely to initiate not on the skin surface, but in deeper tissue layers, and the tissues underlying the distal bony prominences of the medial metatarsals are the most vulnerable ones.

Computer Simulation↗
PubMed1995

Synovial hemangioma: imaging features in eight histologically proven cases, review of the literature, and differential diagnosis.

OBJECTIVE: This study was undertaken to describe the imaging characteristics of synovial hemangioma, with the goal of improving the disappointing rate (22%) of clinical diagnosis of this condition. A review of the literature and the differential diagnosis of intra-articular lesions, including synovial osteochondromatosis and pigmented villonodular synovitis, are also presented. PATIENTS: The subjects of the study were 8 patients (4 males, 4 females; age range: 5-47 years; mean age: 19 years) with histologically confirmed synovial hemangioma involving the knee (n = 7) or wrist (n = 1). We retrospectively examined the imaging studies performed in these patients, including plain radiography (n = 8), magnetic resonance imaging (MRI; n = 4), angiography (n = 3), arthrography (n = 2), and contrast-enhanced computed tomography (CT; n = 2). RESULTS: Plain radiographs showed a soft tissue density suggesting either joint effusion or a mass in all patients. Phleboliths and bone erosions on plain films in four patients with extra-articular soft tissue involvement pointed to the correct diagnosis. Angiography, showing fine-caliber, smooth-walled vessels, contrast pooling in dilated vascular spaces, and early visualization of venous structures, was diagnostic in two patients. Neither arthrography nor CT yielded specific enough findings. MRI was consistently effective in allowing the correct diagnosis to be made preoperatively, showing an intra-articular or juxta-articular mass of intermediate signal intensity on T1-weighted images and of high signal intensity of T2- or T2*-weighted images with low-signal channels or septa within it. A fluid-fluid level was found in two patients with a cavernous-type lesion. CONCLUSION: Despite the limited nature of this study, it shows clearly that MRI is the procedure of choice whenever an intra-articular vascular lesion such as synovial hemangioma is suspected. Nonetheless, phleboliths and evidence of extra-articular extension of plain radiographs point to angiography as an effective procedure of first resort because it can be combined with embolotherapy.

Adolescent↗
PubMed1990

Acute cervical spine trauma: correlation of MR imaging findings with degree of neurologic deficit.

A retrospective analysis of magnetic resonance (MR) imaging studies of 78 patients with acute cervical spinal cord injuries was undertaken to determine which observations related directly to the neurologic injury. All MR imaging studies were performed on a 1.5-T unit and assessed with respect to 14 parameters related to the bony spine, ligaments, prevertebral soft tissues, intervertebral disks, and spinal cord. Forty-eight patients also underwent non-contrast material-enhanced thin-section computed tomography (CT) of the cervical spine. MR imaging was the definitive modality in the assessment of soft-tissue injury, especially in the evaluation of the spinal cord and intervertebral disks. All patients with a neurologic deficit had abnormal spinal cords at MR imaging. Intramedullary hemorrhage was predictive of a complete lesion. The degree of associated bone and soft-tissue injury had no bearing on the extent of spinal cord injury or neurologic deficit. Patients with residual cord compression following reduction demonstrated greater neurologic compromise than those without compression.

Acute Disease↗
PubMed1986

Computed tomography of spinal chordomas.

Computed tomography of 16 spinal chordomas revealed lytic lesions, or lytic and blastic lesions, of 2 or more adjacent vertebrae and a fairly well-delineated soft tissue mass in 16 patients. Intravenous contrast enhancement revealed multiple zones of hypodensity in 5 tumors pathologically proved to contain areas of cystic degeneration. Invasion of the epidural space was noted on computed tomography in 2 vertebral and 7 sacral lesions, and on myelography in 7 vertebral lesions. Computed tomography is ideal for delineation of the soft tissue component of these lesions, detection of sacral lesions at an early stage, planning of surgical excision or irradiation treatment, and detection of recurrence.

Adult↗
PubMed1993

Evaluation of tumor blood perfusion by dynamic MRI and CT in patients undergoing thermoradiotherapy.

In 18 patients who were treated with combined regional hyperthermia and radiation for recurrent pelvic tumors, blood flow related data were obtained using dynamic computed tomography and dynamic magnetic resonance imaging. The enhancement of contrast material (delta HU) and Gadolinium DTPA (delta SI) over baseline in the early phase (15-30 s) after bolus injection is dependent upon perfusion. With both methods significant differences in global perfusion have been observed between tumor center and tumor periphery. With regard to the mean perfusion values we are able to separate high, medium and low perfused pelvic tumors. Flow rates expressed as delta HU for dynamic CT and delta SI for dynamic MRI show a significant inverse correlation with the achieved steady state temperatures above baseline. Values of enhancement of contrast material higher than 15-35 delta HU or 300-700 delta SI indicate flow rates which were limiting in achieving steady state temperatures higher than 3 degrees C above baseline (core temperature).

Combined Modality Therapy↗
PubMed1997

A critical appraisal of measurement of the soft tissue outline using photographs and video.

Radiographs are essential in the planning and assessment of treatment, as well as the study of growth patterns, but before subjecting a child to X-rays, the clinician must ensure that it is justifiable on clinical grounds. The use of cephalometric radiography, particularly in the young patient with a cleft of the lip and/or palate, has been questioned. The aim of this project was to investigate the validity and reproducibility of using a photograph or video image, compared with a radiograph, for measurement of the soft tissue profile of the face. A radiographic phantom head was used, which consisted of a dry bone skull encased in a soft tissue substitute. The method involved comparing direct measurement of the head in a Reflex Metrograph with the results of computerized digitizing of a cephalometric radiograph, digitizing a video image from a computer screen and measurement of a photograph. It was found that digitizing of the soft tissue outline of a radiographic phantom head from a video image was neither a valid, nor a reproducible method of replacing cephalometric radiographs in the measurement of the soft tissue profile of the face. A photograph may be a clinically acceptable alternative, but errors from this method are likely to be larger than those due to digitization of a radiograph.

Analysis of Variance↗
PubMed2006

Reduced parameter formulation for incorporating fiber level viscoelasticity into tissue level biomechanical models.

Collagen is known to be a viscoelastic material and therefore is an important source of time dependent behavior in soft tissue. Though there are material models for soft tissue that rely on properties and structure of constituent collagen fibers, such models generally utilize only the elastic properties of collagen, and thus the resulting tissue level response does not possess any viscoelastic features. Here, the time dependent properties of collagen are directly incorporated into a fiber based hyperelastic model using the one dimensional theory of quasi-linear viscoelasticity within the context of a locally defined, anisotropic representation of extracellular matrix structure. The resulting model possesses seven material parameters and, using numerical and computational analysis, is shown to successfully predict many key features of soft tissue response including anisotropy, strain hardening, preconditioning, and rate independent hysteresis. A formulation is also introduced for incorporating fiber level viscoelasticity into structural models derived from a continuous representation of fiber structure.

Animals↗