Soft tissue settings

As with optical colonoscopy, tagged stool frequently abuts a lesion. This makes polyps more conspicuous for detection (Figs. 4.8, 4.9, and 4.10). In these cases polyp conspicuity is improved using soft tissue settings. 

Fig. 4.9.a Small amount of barium abutting a lesion (arrowhead) in the sigmoid and hence improving polyp conspicu-ity. b Improved depiction of the lesion in soft tissue settings, c The prone view shows a partially collapsed sigmoid. The barium again delineates the lesion improving visualisation (white arrow)... 

Fig. 7.4a-d. False positive lesion of retained pill (arrow) with characteristic shift of position a axial 2D MPR supine image (W 1500, L -200) demonstrates a polypoid lesion b axial 2D MPR view in soft tissue window settings (W 400, L 10) better shows low density of pill c axial 2D MRP prone image in soft tissue settings better demonstrates shift to dependent position of pill, consistent with false positive d 3D volume rendered view of pill mimics a polyp... 

Fig.7.8a-c. False positive of confluence of folds (arrows) mimicking a flat lesion a 3D volume rendered view raises concern for a flat lesion b axial 2D MPR in soft tissue settings also demonstrates flat morphology c sagittal 2D MPR best demonstrates confluence of folds... 

The importance of 2D MPR with soft tissue settings (window 400, level 10) needs to be emphasized with these types of lesions. Whether this is subtle mural thickening or advanced, the 2D MPR views give valuable information of the mural relationships, which extend beyond the lumenography of the 3D fly-through (Fig. 7.11). In addition the 3D transparency view, which simulates the barium enema, can be a powerful view to display the lesion for others to appreciate the size and location of the cancer. 

Fig. 7.1 la-e. Subtle advancedmurallesion with polypoid (white arrow) and stalk (white arrowheads) components, along with infiltrative T3 mural invasion (open arrows), best seen in soft tissue MPR views a supine axial 2D MPR (W 1500, L -200) does not demonstrate lesion well, compared to b b supine axial 2D MPR in soft tissue settings (W 400, L20) best demonstrates the polypoid component and flat soft tissue mural infiltration c prone axial 2D MPR shows immersed lesion requires a narrower soft tissue window setting (W 900, L 300) to see through the fluid d optimized 3D view shows polypoid and infiltrative mural components (only seen retrospectively) e corresponding view at optical colonoscopy... 

Fig. 14.10a-c. Normal ileo-cecal valve. The valve should be symmetric with respect to the valve orifice on a 2D view c 3D view b by narrowing the window and level settings to soft tissue settings, one can visualize the internal fatty attenuation of the valve and its associated fold (arrow)... 

Fig. 14.20a-d. Fluid can be seen on 3D endoluminal images (a, arrow) and on virtual pathology (b, arrow) as filling defects. Axial 2D image demonstrates an air-fluid level (c, arrow) and soft tissue setting shows that the filling defects not have soft... 

As a preeminent biomaterial, silicones have been the most thoroughly studied polymer over the last half century. From lubrication for syringes to replacements for soft tissue, silicones have set the standard for excellent blood compatibility, low toxicity durability, and bioinertness. Many medical applications would not have been possible without this unique polymer. 

Local treatment of skin and soft tissue infections with antibiotic-containing ointments or solutions should not be used because it leads to allergic reactions and rapid development of bacterial resistance. In settings where MRSA or resistant Enterobacte-riaceae (like ESBL s gram negative bacteria with extended spectrum beta lactames) or Pseudomonas spp. occur, the empiric use of vancomycin and a carbapenem can be necessary. The risk of transmission of these organisms should be minimalised by hygienic and isolation measures. 

Since the early 2000s, noninvasive techniques such as micro-computed tomography (micro-CT) have been increasingly employed to aid in the simultaneous visualization of skeletal and soft tissues. Additionally, the ability to digitize images for mathematical analysis of data sets has progressed to the point where it appears likely that standard methods for visualization and evaluation are about to change. 

Fig. 2. Soft tissue imaging can be accomplished in pre- and postnatal specimens by micro-CT. Top rowdepicts a maximum intensity projection or WIIP view of an El 5 mouse embryo left) and PO mouse pup (right). Bottom rowdepicts a 2D slice view, technically termed a reformat, of the same El 5 (left) and PO (right) from the data set depicted above. The soft tissue features can be seen along with skeletal signal as volumetric or two-dimensional slices of the specimen in all anatomical viewing planes, including oblique angles, if desired.

TNF- has been extensively tested in the therapy of various malignancies, but results have been disappointing due to dose-limiting toxicities. One exception is the use of intra-arterial high-dose TNF- for malignant melanoma and soft tissue sarcoma of the extremities. In these settings, response rates greater than 80% have been noted. 

A striking aspect of lead in the body is its very rapid transport to bone and storage there. Lead tends to undergo bioaccumulation in bone throughout life, and about 90% of the body burden of lead is in bone after long-term exposure. The half-life of lead in human bones is estimated to be around 20 years. Some workers exposed to lead in an industrial setting have as much as 500 mg of lead in their bones. Of the soft tissues, the liver and kidney tend to have somewhat elevated lead levels. 

The proper route of administration for an antimicrobial depends on the site of infection. Parenteral therapy is warranted when patients are being treated for febrile neutropenia or deep-seated infections such as meningitis, endocarditis, and osteomyelitis. Severe pneumonia often is treated initially with intravenous antibiotics and switched to oral therapy as clinical improvement is evident. Patients treated in the ambulatory setting for upper respiratory tract infections (e.g., pharyngitis, bronchitis, sinusitis, and otitis media), lower respiratory tract infections, skin and soft tissue infections, uncomplicated urinary tract infections, and selected sexually transmitted diseases may receive oral therapy. 

Patterns of mesenchymal differentiation in cutaneous neoplasms are no less diverse than those encountered in deeper soft tissues. Fibroblastic or myofibroblastic, fibrohistiocytic, muscular, neural, epithelial, and vascular lesions may be seen as primary tumors in the dermis and subcutis. As is also true in deep soft tissues, the histologic evaluation of those neoplasms may fail to provide an unequivocal diagnosis. Hence immunophenotyping has proven to be valuable in this context. The diagnostic separation of various spindle-cell, polygonal-cell, epithelioid-cell, and small-cell lesions of the skin is assisted in many settings by immunohistochemical analysis. 

The solitary fibrous tumor (SET) is a soft tissue tumor (see Chapter 4). It resembles fibrous meningioma but has a different immunohistochemical profile (see Figs. 

Because the reductions in Hounsfield attenuation accompanying early stroke are small - indeed, often barely perceptible to the human eye - the precise window and level settings (measured in HU) used for CT image review are important variables in the detection of subtle ischemic hypodensity. These settings are known to influence lesion conspicuity and diagnostic accuracy in diseases other than stroke. For example, in the CTA evaluation of severe carotid artery stenosis, optimal window and level viewing parameters are required for precise luminal diameter measurement [23-25]. In abdominal CT, the routine use of narrow liver windows has been advocated in order to improve soft tissue contrast within the liver, thereby increasing the conspicuity of subtle lesions [26]. 

Zinc oxide-eugenol is a somewhat old-fashioned material, but it is widely used as an endodontic sealer [18]. It has relatively poor mechanical properties, but is easy to use in the dental clinic [19] and outcomes are good, which explains its continuing popularity. When set, it is biocompatible towards dental hard tissues, though it is cytotoxic towards soft tissues [20]. Zinc oxide-eugenol is susceptible to hydrolysis, which causes the material to decompose and release eugenol. It is this latter substance which is responsible for the cement s adverse effects on soft tissues, but which also makes the material bactericidal. 

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