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PubMed1992

Tuberculosis of the odontoid bone: a rare but treatable cause of quadriplegia.

Radiologic investigation plays an important role in the diagnosis and management of tuberculosis of the odontoid bone. Immediate confirmation of the condition by examination of tissue and surgery may save lives and reduce the morbidity rate substantially. When the clinical history is appropriate, a diagnosis of tuberculosis is strongly suggested by plain films of the cervical spine showing precervical swelling of the soft tissues, narrowing of the disk spaces and focal erosion of the bones and by computed tomography scans demonstrating details of the soft-tissue abnormality, focal bony erosion and sclerosis.

Adult↗
PubMedDate not supplied

Axial computed tomographic anatomy of the foot. Part II: Midfoot.

Osseous and soft tissue anatomy of the human midfoot is presented as visualized on high resolution axial computed tomography (CT). Because of the proven and potential capabilities of CT in the diagnosis of midfoot disorders, this report serves as an important standard for comparison with clinical studies.

Calcaneus↗
PubMed2002

Osteosarcoma of the temporomandibular joint: report of 2 cases.

The aim of this article is to report 2 cases of osteosarcoma of the mandibular condyle, a rare pathological condition, and to emphasize and discuss the usefulness of different imaging modalities in the diagnosis and evaluation of osteosarcoma of the temporomandibular joint. In our assessment of the different imaging modalities, we found that 2-dimensional computed tomograms provide excellent detection of tumor calcification, cortical involvement, and in most instances, soft tissue and intramedullary extension, whereas 3-dimensional computed tomography vascular protocol can help to define the extension of the lesion, improving the visualization of the lesion's relationship to the adjacent anatomical structures. Magnetic resonance imaging is more effective in demonstrating the intramedullary and extraosseous tumor components on T2 weighted images. Because metastasis from body tumors to the maxillofacial region occurs occasionally, it is useful to examine the oral cavity when symptoms first appear and devote special attention to the subtle changes that may indicate early metastatic involvement.

Adolescent↗
PubMed1981

The value of angiography in planning surgical treatment of bone tumors.

Evaluation of 314 angiograms revealed that they were often very useful in planning nonablative resection of bone tumors because they demonstrated the relationships of the tumors to major vessels. Increasing experience indicates that computed tomography can accurately define intraosseuous and soft-tissue extent of bone tumors. If vascular relationships are not precisely shown by computed tomography, angiography may still be required. The angiograms occasionally also helped in anticipating operative blood loss, demonstrating variants of vascular anatomy, or planning biopsy. Meticulous angiographic technique and close communication between surgeon and angiographer are essential.

Bone Marrow Diseases↗
PubMed1993

Extraskeletal mesenchymal chondrosarcoma.

Among seven patients with extraskeletal mesenchymal chondrosarcoma (EMC), three children (aged 3-6 years) developed EMC in a central location and four adults (aged 38-54 years) developed EMC in both central and peripheral sites. Conventional radiography and tomography and computed tomography (CT) depicted EMC as a soft-tissue mass with ring, arc, stippled, and highly opaque calcifications in four patients. Contrast-enhanced CT showed lobulation and peripheral tumoral enhancement, sometimes with central low-attenuation areas. On magnetic resonance (MR) images, EMC was a lobulated mass with high signal intensity on T2-weighted images and enhancement with low-signal-intensity focal areas on contrast-enhanced T1-weighted images. All adults developed recurrences and/or metastases and died. Of the three children, two were living and free of disease at the end of the study and the third child died of chemotherapeutic-induced leukemia. Although imaging features of EMC are nonspecific, its chondroid-type calcifications and foci of low signal intensity within enhancing lobules may reflect its dual histopathologic morphologic characteristics of differentiated cartilage islands interspersed within vascular undifferentiated mesenchyme.

Adult↗
PubMed2002

Calcium scoring of the coronary artery by electron beam CT: how to apply an individual attenuation threshold.

OBJECTIVE: Our aim was to assess the inter- and intraindividual variability of the attenuation threshold used to identify coronary artery calcification on electron beam CT and to illustrate a new threshold method. MATERIALS AND METHODS: We measured the soft-tissue attenuation of regions surrounding the coronary arteries at the level of the left main coronary artery ostium (high level) and at the bottom of the heart (low level) in 48 consecutive patients (22 men, 26 women). Mean +/- 2 standard deviations (SD) of soft-tissue attenuation and variance of soft-tissue density and SDs were calculated at each level for every patient. It was assumed that setting an attenuation threshold greater than or equal to 3 SDs above that of soft tissue at each myocardial level would eliminate 99.5% of all scatter artifacts, allowing precise identification of calcific deposits. RESULTS: For the entire patient cohort, the average soft-tissue attenuation was 41 H and 35 H at the high and low levels, respectively (p < 0.01), indicating a large intraindividual variability. The SDs of soft-tissue attenuation measured by the computer software at the high and low levels were not different (26 H at the high level and 28 H at the low level; p = not significant). However, the calculated SD of the individual mean soft-tissue attenuation was 5 H at the high level and 8 H at the low level, again indicating a large intraindividual variability (p < 0.01). The addition of 3 measured SDs above the mean individual soft-tissue attenuation predicted a mean threshold of 120 and 121 H at the high and low levels, respectively, but with a wide interindividual variability (83-193 H at the high level and 79-242 H at the low level). There was a strong correlation between body weight and SD of soft-tissue attenuation at the low level (r = 0.75, p < 0.001) and a weaker but statistically significant correlation between weight and SD of soft-tissue attenuation at the high level (r = 0.51, p < 0.001). CONCLUSION: For the patients in this study, a threshold of 120 H for the detection of coronary calcification by electron beam CT seemed more appropriate than a threshold of 130 H, which is currently in use. However, given the great inter- and intraindividual variability, a biologic threshold tailored to the individual patient and to each individual imaging level should be used instead of a fixed threshold.

Aged↗
PubMed2007

The utility of deep soft-tissue cultures in diagnosing the causative agent of sternal osteomyelitis following median sternotomy.

BACKGROUND: The authors' goal was to determine whether the bacteria cultured from the mediastinal deep soft tissues matched those identified by the sternal bone cultures in cases of mediastinitis with clinically suspected sternal osteomyelitis, in hopes of eliminating the need for sternal bone biopsy. METHODS: The authors retrospectively reviewed the charts of 27 Detroit Medical Center patients who underwent median sternotomy and developed mediastinitis with clinical suspicion of osteomyelitis between 1996 and 2004. RESULTS: Although only 18 of 27 of the authors' patients had positive bone cultures, they demonstrate that in 94 percent (17 of 18) of these patients, the organisms cultured from the mediastinal deep soft-tissue cultures matched those cultured from the positive sternal bone cultures. CONCLUSIONS: With the results obtained from this study, the authors hope to promote a less-invasive means of investigating osteomyelitis in sternal wounds, to prevent the complications associated with obtaining a bone biopsy specimen in a contaminated soft-tissue setting. Instead, the authors suggest thoracic computed tomographic scanning as a noninvasive means of clinically demonstrating osteomyelitis of the sternum, and culture of the deep soft tissues of the mediastinum at the time of mediastinal debridement to determine the offending organism, if osteomyelitis is suggested by computed tomographic scan.

Aged↗
PubMed2003

A comparison of conventional film, CR hard copy and PACS soft copy images of the chest: analyses of ROC curves and inter-observer agreement.

STUDY OBJECTIVE: The aim of this study was to determine whether the accuracy of diagnosis of a spectrum of chest pathology was affected by the imaging technique used, and to compare conventional film/screen, hard copy computed (phosphor plate) radiography (CR) and soft copy CR (PACS) images. MATERIALS AND METHODS: For each of 44 patients who had a CT examination of the thorax, PA and lateral chest radiographs were produced using conventional film, hard copy CR and soft copy PACS images. Five radiologists independently scored all images for the presence of abnormalities. The data were analysed in two stages using the result of the CT scan as the reference standard diagnosis: firstly, to investigate differences in abnormality scores between image modalities and observers using ROC analysis; secondly, to investigate the agreement of the diagnoses with the reference standard by the analysis of kappa scores. RESULTS: The ROC analyses and comparison of kappa scores showed no differences between image modalities (P=0.72, P=0.87), but highly significant differences between observers (P<0.001, P=0.003). CONCLUSION: The detection of chest lesions did not vary between conventional film, CR hard copy and PACS soft copy images. For all three image types, there were statistically significant differences between observers.

Analysis of Variance↗
PubMed2001

Modelling soft tissue for kinematic analysis of multi-segment human body models.

Traditionally biomechanical models represent the musculoskeletal system by a series of rigid links connected by rigidly defined rotational joints. More recently though the mechanics of joints and the action of soft tissues has come under closer scrutiny: biomechanical models might now include a full range of physiological structures. However, soft tissue representation, within multi-segment human body models, presents significant problems; not least in computational speed. We present a method for representing soft tissue physiology which provides for soft tissue wrapping around multiple bony objects; while showing forces at the insertion points, as well as normal reactions due to contact between the soft and bony tissues. These soft tissue representations may therefore be used to constrain the joint, as ligaments would, or to generate motion, like a muscle, so that joints may be modelled which more accurately simulate musculoskeletal motion in all degrees of freedom--rotational and translational. This method produces soft tissues that do not need to be tied to a certain path or route between the bony structures, but may move with the motion of the model; demonstrating a more realistic analysis of soft tissue activity in the musculoskeletal system. The combination of solid geometry models of the skeletal structure, and these novel soft tissue representations, may also provide a useful approach to synthesised human motion.

Biomechanical Phenomena↗
PubMed2002

Segmentation of MR images for computer-assisted surgery of the lumbar spine.

This paper describes a segmentation algorithm designed to separate bone from soft tissue in magnetic resonance (MR) images developed for computer-assisted surgery of the spine. The algorithm was applied to MR images of the spine of healthy volunteers. Registration experiments were carried out on a physical model of a spine generated from computed tomography (CT) data of a surgical patient. Segmented CT, manually segmented MR and MR images segmented using the developed algorithm were compared. The algorithm performed well at segmenting bone from soft tissue on images taken of healthy volunteers. Registration experiments showed similar results between the CT and MR data. The MR data, which were manually segmented, performed worse on visual verification experiments than both the CT and semi-automatic segmented data. The algorithm developed performs well at segmenting bone from soft tissue in MR images of the spine as measured using registration experiments.

Algorithms↗
PubMedDate not supplied

Axial computed tomographic anatomy of the foot. Part I: Hindfoot.

Osseous and soft tissue anatomy of the human hindfoot is presented as visualized on high-resolution axial computed tomography (CT). Radiologic-pathologic correlation with the use of a cadaver specimen and contiguous CT sections 1.5 mm. thick was performed for structural identification. The foot of a healthy senior citizen was scanned by using 5.0-mm. slice thickness. Because of the proven and potential capabilities of CT in the diagnosis of hindfoot disorders, this report serves as an important standard for comparison with clinical studies.

Calcaneus↗
PubMed2003

Characterization of maxillofacial soft tissue vascular anomalies by ultrasound and color Doppler imaging: an adjuvant to computed tomography and magnetic resonance imaging.

PURPOSE: The special imaging and physical properties of ultrasound and color Doppler offer opportunity for continued investigation in oral and maxillofacial surgery. This study prospectively investigated ultrasound and color Doppler in addition to computed tomography (CT) and magnetic resonance imaging (MRI) in the characterization of several vascular or suspected vascular anomalies and assesses the value of ultrasound and color Doppler in their diagnoses. PATIENTS AND METHODS: Six patients with vascular or suspected vascular anomalies seen between 1997 and 1999 composed the study group. All patients were clinically evaluated, imaged by CT with contrast and/or MRI with contrast, ultrasound, and Doppler (including color, spectral, and power). Ultrasound studies were performed in the presence of the referring oral and maxillofacial surgeons to provide consultation on anatomy and differential diagnosis as well as to witness the dynamic study. Three patients were further studied by angiography. The Mulliken/Glowacki classification (Plast Reconstr Surg 69:412, 1982) and designations and the Jackson et al modification (Plast Reconstr Surg 91:1216, 1993) are used in this study. RESULTS: A spectrum of lesions emerged in this small case series. Detailed clinical and imaging findings and a summary of diagnostic impressions allowed general and specific observations and permitted assessment of the value of ultrasound and color Doppler in the diagnosis of these lesions. The diagnostic accuracy of ultrasound and Doppler was equal to or better than that of CT and/or MRI in 4 of 6 cases. In the other 2 cases ultrasound did not specifically diagnose the lesions but did allow assessment of vascularity. In one of these cases the correct diagnosis was made by a combination of CT and angiography, and in the other the diagnosis was made by nonenhanced MRI. An ancillary study showed that the combination of nonenhanced MRI with ultrasound and Doppler provides more information than contrast-enhanced MRI alone and is more cost effective. CONCLUSIONS: 1) A single imaging modality is frequently unable to provide sufficient diagnostic information to allow confident clinical management of a vascular malformation. 2) A team approach and conferencing between imaging specialists and clinicians promote better diagnosis and management. 3) Nonenhanced MRI with ultrasound/color Doppler can be substituted for enhanced MRI to provide the best diagnostic information and at reduced cost. 4) Ultrasound/color Doppler is an important adjuvant to CT and MRI in the diagnosis of vascular or suspected vascular anomalies.

Adenocarcinoma↗
PubMed1986

[Computerized tomography in the assessment of soft-tissue neoplasms. Observations in 124 cases].

In order to evaluate the role of Computed Tomography (CT) in prediction of nature, staging and follow-up of soft-tissue tumors, the authors examined by CT 124 patients with soft tissue neoplasms who later underwent surgery (116 cases) or fine needle biopsy (8 cases). Comparison between CT and surgical or anatomical results showed that CT was able to correctly predict the benignancy or malignancy of the masses in 76% of cases but it was very seldom able to allow an histological prediction. On the contrary CT was found to be a very useful tool for pre-therapeutic staging and follow-up of the tumors, because it gave many diagnostic information which influenced therapeutic choices and strategies.

Adolescent↗
PubMed1997

[Carotid dislocation. The pictures with computed tomography and magnetic resonance].

INTRODUCTION: Prevertebral retropharyngeal soft tissue widening can be recognized in acute trauma patients in the presence of acute bleeding from cervical vertebral fracture. Abscesses, tumors and neoplastic effusions from nearby cervical spaces can also widen precervical soft tissues and a new cause has been recently suggested, that is the so-called carotid transposition. MATERIALS AND METHODS: We examined eight patients (six women and two men) aged 65 to 75 years. Carotid transposition was found in four patients during examination for acute cervical trauma, while four cases were detected at CT studies performed for other indications, mostly lymphoma staging. CT was always performed with the i.v. injection of a contrast agent and volume scans were used in four cases. MR angiography (MRA) was also used in two patients to study an internal carotid artery stenosis previously detected at color Doppler. RESULTS: Lateral radiographs of the cervical spine of our acute trauma patients showed widened soft tissues in three cases, but no calcific arterial plaques were found. The common carotid arteries were displaced in five patients and the internal carotid arteries in three. Carotid transposition was bilateral in six patients while only the right common and the left internal carotids were involved in two patients. No traumatic hemorrhagic effusion was found on CT images. CONCLUSIONS: Carotid transposition is a mostly asymptomatic abnormality, but it must be considered in acute cervical trauma patients where the precervical soft tissues are widened because hemorrhagic effusion could be misdiagnosed. Thus, this unusual location of the carotid arteries is important because these vessels may be injured during emergency or surgical procedures.

Acute Disease↗
PubMed1986

[High-resolution computer tomography of osseous changes following radical operation of the maxillary sinuses].

The opacification of the maxillary sinuses following Caldwell-Luc procedure seen with plain films depends to a great deal on bony changes. Based on 60 cases the advantages of the computed tomography especially in high-resolution mode are described in comparison with plain films. CT-scans clearly demonstrate the bony changes following Caldwell-Luc procedure, they show the size of the air-filled antrum and reveal inflammation of fibrous soft tissue within the sinus maxillares. Computed tomography facilitates differential diagnosis with regard to other pathological changes of the antrum. If radiological examination following Caldwell-Luc procedure is indicated, CT represents the method of choice.

Cicatrix↗
PubMed1999

Comparison of the late results of mandibular reconstruction using nonvascularized or vascularized grafts and dental implants.

PURPOSE: This study evaluates contour restoration in segmental defects of the mandible and the survival rate of endosseous implants placed into these reconstructions. PATIENTS AND METHODS: Forty-four patients with 23 nonvascularized grafts and 21 patients with vascularized bone flaps were included in the study. The lateral and the sagittal extension of the contour of both the mandibular bone and the overlying soft tissues was determined from serial computed tomography (CT) scans in defined planes through the reconstructed mandible. The success rate of dental implants was determined by a life-table analysis. RESULTS: Average lateral deviation of the reconstructed side from the nonreconstructed side was 4.3 mm (nonvascularized grafts) and 5.6 mm (vascularized grafts). The soft tissue contour followed the skeletal contour quite closely, with slightly smaller degrees of deviation. Asymmetry was greatest in the area of the horizontal ramus. In some cases, skeletal deviation was intentionally produced to compensate for a soft tissue deficit on the reconstructed side. However, in some cases, a major deviation of bone contour was associated with considerable deviation of the soft tissue contour (maximum, 10.5 mm). The cumulative implant success rate was 100% after 5 years and 60.3% after 10 years. None of the seven implant failures accounted for prosthetic failure. CONCLUSIONS: Although there are minor differences, both nonvascularized and revascularized grafts allow for satisfactory contour restoration in segmental reconstructions of the mandible. Implants placed into these grafts provide a reliable basis for dental rehabilitation.

Analysis of Variance↗
PubMed2006

Simulation of soft tissue failure using the material point method.

Understanding the factors that control the extent of tissue damage as a result of material failure in soft tissues may provide means to improve diagnosis and treatment of soft tissue injuries. The objective of this research was to develop and test a computational framework for the study of the failure of anisotropic soft tissues subjected to finite deformation. An anisotropic constitutive model incorporating strain-based failure criteria was implemented in an existing computational solid mechanics software based on the material point method (MPM), a quasi-meshless particle method for simulations in computational mechanics. The constitutive model and the strain-based failure formulations were tested using simulations of simple shear and tensile mechanical tests. The model was then applied to investigate a scenario of a penetrating injury: a low-speed projectile was released through a myocardial material slab. Sensitivity studies were performed to establish the necessary grid resolution and time-step size. Results of the simple shear and tensile test simulations demonstrated the correct implementation of the constitutive model and the influence of both fiber family and matrix failure on predictions of overall tissue failure. The slab penetration simulations produced physically realistic wound tracts, exhibiting diameter increase from entrance to exit. Simulations examining the effect of bullet initial velocity showed that the anisotropy influenced the shape and size of the exit wound more at lower velocities. Furthermore, the size and taper of the wound cavity was smaller for the higher bullet velocity. It was concluded that these effects were due to the amount of momentum transfer. The results demonstrate the feasibility of using MPM and the associated failure model for large-scale numerical simulations of soft tissue failure.

Animals↗