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At least 1,117 records · Page 62Linked to original sources
PubMed1992

Delayed presentation of oesophageal perforation simulating intrathoracic malignancy.

We report two patients with silent oesophageal perforation. In neither patient was the diagnosis made preoperatively by the referring physicians and a history of swallowing difficulty was elicited in only one patient. The appearances on computed tomography were very similar in both patients: there was a soft tissue mass in the upper retro-oesophageal region with destruction of the underlying vertebral body.

Aged↗
PubMedDate not supplied

Computed tomography diagnosis of isolated splenic torsion in a dog.

Isolated splenic torsion in a dog was diagnosed using computed tomography (CT). The enlarged non enhanced spleen and a twisted soft tissue mass effect represented the rotated pedicle were the main findings. Abdominal radiography and ultrasonography were not conclusive.

Animals↗
PubMed2003

Reactivation in post-traumatic chronic osteomyelitis: ultrasonographic findings.

OBJECTIVE: To describe the ultrasound (US) features of reactivation in post-traumatic chronic osteomyelitis in adults. METHODS: Twelve patients with clinical suspicion of reactivation of chronic osteomyelitis, secondary to trauma, surgery, and who were investigated with US were selected for the study. The following US features were assessed: periosseous fluid collection, bone changes (periosteal reactions, cortical irregularity, callus, sequestrum and cloaca) and soft-tissue changes (cellulitis and sinus tracts). US findings were correlated with plain radiography (n = 11), computed tomography (n = 3) and magnetic resonance imaging (n = 2). RESULTS: US detected fluid collections in all patients (12 periosseous and 3 in soft tissues), bone changes in 10 and sinus tracts and cellulitis in 5 patients each. Bone changes detected were cortical irregularity (n = 10), discontinuity of cortex (n = 7), sequestrum (n = 2), callus (n = 2), periosteal reaction (n = 1) and cloaca (n = 1). Cellulitis was seen in 5 patients and sinus tracts in 5. Reactivation was confirmed at surgery in all patients. CONCLUSION: US is a reliable noninvasive imaging modality for the diagnosis of reactivation of post-traumatic chronic osteomyelitis in adults.

Adult↗
PubMed1990

Magnetic resonance imaging of musculoaponeurotic fibromatosis.

Musculoaponeurotic fibromatosis can be mistaken for soft-tissue sarcoma both clinically and on X-ray computed tomography. Magnetic resonance imaging (MRI) in three patients with this condition enabled the correct diagnosis to be made prospectively in two. The appearance on MRI of a heterogeneous mass with well-defined, predominantly peripheral areas of very low signal intensity due to dense fibrous tissue and areas of medium to high signal intensity corresponding to a more cellular stroma should raise the the suspicion of musculoaponeurotic fibromatosis. Cellular areas within the tumour showed moderate enhancement after gadolinium diethylene triamine pentaacetic acid administration.

Adult↗
PubMed1986

Comparison of nuclear magnetic resonance imaging and computed tomography in the diagnosis of upper cervical spinal cord compression.

Because of its ability to visualize soft-tissue structures in greater detail than any previous radiographic modality, nuclear magnetic resonance (NMR) has been heralded as one of the greatest advances in recent years. It is particularly well suited in diagnosis of spinal disorders since it can visualize the spinal cord and cerebrospinal fluid without intrathecal contrast agents. This is a preliminary report of our experience of NMR examination in 106 patients studied since November 1982 at Case Western Reserve University Hospital. One of the best applications of NMR is for compressive lesions of the upper cervical spine because "functional" images can be obtained. The information from NMR was compared with computed tomography (CT) in 14 patients with various etiologies of neural compression--atlanto-occipital subluxation in Down's syndrome, fixed post-traumatic atlantoaxial subluxation, rheumatoid atlantoaxial subluxation and basilar impression of the odontoid, ossification of the posterior longitudinal ligament, Klippel-Feil syndrome, congenital spinal stenosis, cervical spondylosis, Arnold-Chiari malformation, etc. Unlike CT, NMR can directly image in the sagittal plane without computer reformatting of axial cuts. This readily provides direct images of the spinal cord in neutral, flexion, and extension to show the mechanism of neural compression. Disadvantages of NMR compared with CT include poorer image resolution, slightly increased imaging time, and no patients with intracranial aneurysm clips or cardiac pacemakers can be studied. Advantages include no radiation exposure, no intrathecal contrast agent is required to differentiate CSF from neural tissue, and direct sagittal, coronal, and oblique images can be obtained. As a result of this preliminary experience, computed tomography and nuclear magnetic resonance imaging appear to be complimentary studies--CT provides better osseous detail, whereas NMR offers superior soft tissue resolution.

Adult↗
PubMed1997

Computer assisted pericardial puncture: work in progress.

Until now, computer assisted surgery has focused primarily on surgical procedures involving rigid anatomical structures. Because soft tissues can be highly mobile and deformable, they may require specific imaging devices, suitable modeling tools, and guiding systems. Percutaneous pericardial puncture is a good clinical target for computer assisted surgery; this procedure is often performed without direct visualization and is dangerous even though echographic control is used. Computer assistance can greatly improve this technique and will allow accurate puncture of preplanned targets. This paper describes a new approach for computer assisted pericardial punctures (CASPER) and describes a first feasibility analysis of CASPER demonstrated with anesthetized animals. The approach is based on the use of echographic data localized in space, from which an optimal strategy is defined. Because of the specificity of the pericardial effusion, a stable target can be selected despite the heart motions. A passive guiding system is used. We have demonstrated the feasibility of the approach.

Animals↗
PubMed1989

[Soft tissue diagnosis of the shoulder joint using sonography, computerized tomography and magnetic resonance tomography (MRT)].

Injuries and degenerative alterations of the shoulder predominantly affect the soft tissue. To investigate this area we use a multitude of diagnostic examinations: apart from clinical and functional diagnosis also the image reproductive methods of arthrography, ultrasound and computer tomography in addition to the classical X-ray. To ascertain pathological changes to shoulder soft tissue the simplest and quickest, least dangerous and most straightforward examination is the sonograph as it includes dynamic movement procedures. Warning: a high degree of experience and anatomical knowledge is a must! Computer- and especially nuclear spin tomography--being static examining forms a comprehensive picture of every anatomic structure and its pathology--may well represent a valuable addition to shoulder diagnostics. Nevertheless, as yet the clinical and material requirements are still enormous.

Humans↗
PubMed1992

Intracranial findings in progressive facial hemiatrophy.

There have been infrequent reports of cerebral lesions associated with progressive facial hemiatrophy. Six children with progressive facial hemiatrophy were evaluated. Four were referred for evaluation of neurological deficits: 2 with seizures, one with left hemiparesis and one with learning problems. The remaining 2 patients had only facial hemiatrophy. Cranial computed tomography (CT) in 5 patients revealed the bony and soft tissue defects, but cerebral calcifications were seen in only 3 patients. Cranial magnetic resonance imaging (MRI) demonstrated areas of increased signal in the ipsilateral white matter on T2 weighted images in all 5 patients with upper facial atrophy. Ipsilateral cerebral lesions with progressive facial hemiatrophy may be more common than once believed. MRI sometimes reveals abnormalities of the white matter even in patients without neurologic symptoms, and may be more sensitive than CT in the diagnostic evaluation of patients with progressive facial hemiatrophy.

Adolescent↗
PubMed2000

Brain metastasis in patients with sarcoma: an analysis of histological subtypes, clinical characteristics, and outcomes.

BACKGROUND: The clinical characteristics of brain metastasis from sarcoma are not well known. We examined the incidence and the characteristics of brain metastasis in patients with sarcomas. METHODS: All sarcoma patients treated at our institution from 1975 to 1998 were reviewed for brain metastasis. Diagnosis of the primary tumor was confirmed histologically, and brain metastasis was confirmed using computed tomographic (CT) brain scan. RESULTS: Brain metastasis was found in 27 (5.6%) of 480 patients with systemic sarcoma (7.2% soft part sarcoma, 3.5% bone sarcoma, 15.1% distant metastasis). Of these 27 sarcoma patients with brain metastases, lung metastasis occurred in 16 patients (59.3%). Out of 10 patients surgically treated, 8 patients survived more than 16 months. Median survival period after craniotomy was 25.4 months. CONCLUSIONS: We recommend aggressive treatment for those patients with brain metastases whose performance scores are over 70.

Adolescent↗
PubMed1983

CT in pyogenic osteomyelitis of the spine.

Six patients with bacteriologically proven pyogenic osteomyelitis of the spine were followed serially with computed tomography (CT). Initial evaluation of the involved vertebral bodies and adjacent soft tissues showed a drop in CT numbers when compared to normal cancellous bone and soft tissues. A soft-tissue mass was seen in all cases. After appropriate antibiotic therapy, all six patients showed an increase in bone density and a diminution of the soft-tissue mass (p less than 0.05). Five of the six patients showed a further decrease in soft-tissue CT numbers.

Adult↗
PubMedDate not supplied

Validity of the concept of separating primary and scatter dose.

The technique of separating dose into primary and scatter components for calculating photon dose distributions is widely used. The primary and scatter dose models ignore ignore the fact that electrons have a finite range. This may be a good approximation for 60Co photons but not for higher energies. For the latter, the range of electrons may be several centimeters in soft tissue and even longer in lungs and will lead to errors in computed dose in regions where electronic equilibrium does not exist. Ignoring the finite range of electrons will affect dose at points such as those near the beam boundaries, near inhomogeneity boundaries, and at bone-soft-tissue interfaces. Other possible problems associated with the definition and use of "primary" and "scatter" dose in dose distribution calculations result from extrapolation of measured data to obtain data for zero and very large field sizes and from the use of these quantities, which are defined for central axis, for points at large distances from the central axis. This paper examines the limits of the validity of these assumptions.

Cobalt Radioisotopes↗
PubMed2000

A software system for interventional magnetic resonance image-guided prostate brachytherapy.

OBJECTIVE: Current prostatic brachytherapy implant procedures use ultrasound imaging for geometric guidance during surgery, with pre-surgical planning based on ultrasound images and post-surgical dosimetry based on computed tomography (CT). This procedure suffers from the poor soft-tissue contrast of ultrasound and CT and problems inherent in the repositioning of the patient at surgery. We have designed and implemented an integrated real-time imaging and treatment-planning software system that combines the superior soft-tissue contrast of magnetic resonance (MR) images with the real-time acquisition of those images for localization, verification, and dosimetric purposes. The system permits the surgeon and patient to complete all phases of treatment in one setting. MATERIALS AND METHODS: We utilize an intra-operative MR unit that permits real-time imaging and stereotactic localization during a surgical procedure. Our software system integrates with the unit and features (i) a calibration schema to calibrate the prostatic surgical implant template within the unit, (ii) full volumetric data acquisition of the prostate, (iii) interactive three-dimensional (3D) treatment planning with volumetric dose evaluation, and (iv) geometric and dosimetric feedback during the surgical procedure. We utilize a software architecture that uses mediators between the abstract data types, or objects. These mediators communicate state changes in individual objects (e.g., a change in a catheter position) to other objects (e.g., a dose-volume histogram) that depend on these changes. A consistent 3D representation of the treatment volumes allows interactive reconstruction of the volumes on arbitrary MR image sections and real-time dose computations. RESULTS: We have successfully implemented the system clinically and have treated 143 patients (as of August 2000). The system supports four clinical phases. The first consists of calibrating the implant template with respect to the patient's anatomy and the MR unit. The second consists of acquiring a complete volumetric MR data set of the prostatic volume. The third consists of delineating the treatment volume (often a sub-volume of the prostate) and the dose-limiting critical volumes. These volumes are used in determining the surgical treatment plan based on catheter and seed placement in the prostate and a dosimetric evaluation of all volumes. The final phase consists of implanting the catheters with the radioactive seeds, where each catheter is imaged and compared to the planned position of the catheter, thus allowing a direct comparison, and possible adjustment, of the implanted versus planned catheter position. CONCLUSIONS: The system is highly interactive, and has great flexibility in its design, maintainability, and clinical practice. The system provides an efficient model to support the surgical procedure. The system significantly improves the diagnostic information provided to the clinician and the treatment planner and the geometric accuracy of the surgical procedure compared to ultrasound procedures. The system allows excellent critical structure sparing, both through interactive placement of the catheters with high geometric accuracy and through the definition of the actual sub-prostatic volumes possible with MR.

Brachytherapy↗
PubMed1985

Plantar compartmental infection in the diabetic foot. The role of computed tomography.

This review discusses the role of computed tomography (CT) in the evaluation of extent of plantar soft tissue infection in the diabetic foot. CT abnormalities are correlated with conventional radiography, results of preoperative aspiration cultures, intraoperative assessment, and bone, gallium, and 111In-leukocyte scan findings. Plantar soft tissue disease respects compartmental boundaries in general, with transcompartmental spread possible along musculotendinous units that normally transgress the intervening fascial septae. CT correlates well with the extent of infection as determined by other modalities, but cannot precisely predict its proximal boundary due to gradual transition between unequivocally abnormal and normal tissue. CT may be useful in establishing an appropriate level for contemplated amputation and can detect extension of superficial diabetic foot infections at an earlier stage than existing clinical methods, potentially resulting in less extensive surgical procedures.

Bacterial Infections↗
PubMed2001

Stress distribution of the foot during mid-stance to push-off in barefoot gait: a 3-D finite element analysis.

OBJECTIVE: To quantify stress distribution of the foot during mid-stance to push-off in barefoot gait using 3-D finite element analysis. DESIGN: To simulate the foot structure and facilitate later consideration of footwear. Finite element model was generated and loading condition simulating barefoot gait during mid-stance to push-off was used to quantify the stress distributions. BACKGROUND: A computational model can provide overall stress distributions of the foot subject to various loading conditions. METHODS: A preliminary 3-D finite element foot model was generated based on the computed tomography data of a male subject and the bone and soft tissue structures were modeled. Analysis was performed for loading condition simulating barefoot gait during mid-stance to push-off. RESULTS: The peak plantar pressure ranged from 374 to 1003 kPa and the peak von Mises stress in the bone ranged from 2.12 to 6.91 MPa at different instants. The plantar pressure patterns were similar to measurement result from previous literature. CONCLUSIONS: The present study provides a preliminary computational model that is capable of estimating the overall plantar pressure and bone stress distributions. It can also provide quantitative analysis for normal and pathological foot motion. RELEVANCE: This model can identify areas of increased pressure and correlate the pressure with foot pathology. Potential applications can be found in the study of foot deformities, footwear, surgical interventions. It may assist pre-treatment planning, design of pedorthotic appliances, and predict the treatment effect of foot orthosis.

Adult↗
PubMed2004

Orbital myositis associated with Borrelia burgdorferi (Lyme disease) infection.

OBJECTIVE: To report on the clinical findings in a patient with isolated left inferior rectus myositis associated with serologically confirmed Borrelia burgdorferi infection. DESIGN: Interventional case report. TESTING: Comprehensive clinical, laboratory, and imaging evaluation. RESULTS: Contrast-enhanced computed tomography showed a swollen inferior rectus muscle with infraorbital soft tissue swelling in a patient with diplopia and prior symptoms consistent with manifestations of Lyme disease. Positive serum and cerebrospinal fluid antibodies to B. burgdorferi by enzyme-linked immunoassay were confirmed by Western blot, and the cerebrospinal fluid/serum antibody ratio was elevated. No alternative cause for orbital myositis was found, and treatment with antibiotics resulted in a complete recovery. CONCLUSIONS: Orbital myositis should be added to the expanding list of ophthalmic manifestations of Lyme disease. Correct diagnosis and appropriate antibiotic therapy may reduce the likelihood of further neurologic or ophthalmologic sequelae.

Adult↗
PubMedDate not supplied

Subungual glomus tumor: combined use of MRI and three-dimensional contrast MR angiography.

We describe a case of digital glomus tumor diagnosed by MRI and three-dimensional contrast MR angiography (MRA). Images provided the formal definitive diagnosis and the precise localization of the tumor, guiding the necessary surgical resection. It is possible that noninvasive MRA could replace conventional arteriography for the evaluation of patients with clinical suspicion of glomus tumor.

Contrast Media↗
PubMed2003

Using a human visual system model to optimize soft-copy mammography display: influence of MTF compensation.

RATIONALE AND OBJECTIVES: The investigators developed an efficient method for optimizing cathode ray tube (CRT) monitor performance for digital mammography, based on the correlation between the performance of human observers and the performance of a mathematical computer model of the human visual system. The investigators examined observer performance on soft-copy display of mammographic images that were either unprocessed or processed to compensate for modulation transfer function (MTF) deficiencies in the CRT display. The results were used to validate the human visual system model. MATERIALS AND METHODS: Six radiologists viewed a series of 250 mammographic images with microcalcification clusters with different contrast levels on a CRT monitor. The images were viewed twice: once without image processing and once with processing designed to compensate for MTF deficiencies in the CRT monitor. The images were analyzed with the JNDmetrix Visual Discrimination Model, which is based on the principles of just-noticeable difference measurement and frequency-channel vision modeling. Receiver operating characteristic (ROC) curves were generated for the human observers and compared statistically with the model observers' performance. RESULTS: Both human and model performance was better overall with the MTF-compensated images, especially for microcalcifications in the midlevel contrast range. There was a very high correlation between human and model observers. CONCLUSION: The use of image-processing methods to compensate for limitations in the MTF of CRT monitors can improve the detection performance of radiologists searching for microcalcifications in mammographic images, and a model based on characteristics of the human visual system can be used to predict human observer results accurately.

Computer Simulation↗