Shaded surface display

Alternatively, 3D images of MR angiographies can be calculated using volume rendering techniques (VRT) or shaded surface display (SSD). Both methods, however, depend on threshold values and therefore they carry the risk of unwanted manipulation. They are less suitable for the depiction of stenoses and are commonly used for aneurysms and other vascular malformations. 

Fig 4.19 Incidental aneurysm found during evaluation for acute stroke. The collapsed MIP image shows a cut-off of the left MCA stem (arrow, a) and right MCA aneurysm (arrow, b). Corresponding shaded surface display... 

Surface rendering (shaded surface display, SSD) attempts to display a 3D view of the surface of an object, in a 2D image on the workstation monitor. In a semi-automated process at the workstation, the radiologist must select the object to view, either by using the electronic scalpel tool to separate the area of interest or by altering the CT threshold values displayed. Both methods are simple to perform the latter is less time consuming and works well for bony structures (Dalrymple et al. 2005). SSD makes use of only a portion of the available image data - that... 

Lusk RP, Lazar RH, Muntz HR (1989) The diagnosis and treatment of recurrent and chronic sinusitis in children. Pediatr Clin North Am 36 1411-1421 Magnusson M, Lenz R, Danielsson PE (1991) Evaluation of methods for shaded surface display of CT volumes. Comput Med Imaging Graph 15 247-256 May M, Levine HL, Mester SJ, Schaitkin B (1994) Complications of endoscopic sinus surgery analysis of 2108 patients-incidence and prevention. Laryngoscope 104 1080-1083... 

Table 13.1. Specific advantages of multiplanar reformation, shaded surface display, and color-coded 3D reformations...

Shaded surface display (SSD) Well-suited for visualizing dense tissue, such as bones or bone transplants, but not for soft tissue or tumors of the hypopharynx or larynx... 

Segmentation is used not only to select specific structures for projection. Moreover, binary volumes can also be directly rendered as objects. A shaded surface display (SSD) is a depiction of the surface of such a volume. The user can select surface properties such as colors and reflection. A realistic impression is created... 

Fig. 14.15. Shaded surface display of the rib cage-notice the bilateral serial rib and sternum fractures...

Hong KC, Ereeny PC (1999) Pancreatioduodenal arcades and dorsal pancreatic artery comparison of CT angiography with three-dimensional volume rendering, maximum intensity projection and shaded-surface display. AJR AM J Roentgenol 211 337-343... 

Shaded Surface Display (SSD), Maximum Intensity Projection (MIP), and Minimum Intensity Projection (MinIP) 308... 

CT and MR source images may be processed to generate 3D reconstructions, which can be obtained with both external and endoluminal points of view of the organ anatomy. The maximum intensity projection (MIP), the minimum intensity projection (MinlP), the shaded surface display (SSD), the perspective volume rendering (VR), and the multiplanar volume reconstruction (MPVR) algorithms pro-... 

Three-dimensional medical images of CT and MR data sets can be generated with a variety of computer algorithms. The three most commonly used techniques are shaded surface display (SSD), maximum intensity projection (MIP) and 3D volume rendering (Calhoun et al. 1999). 

Fig. 29.12. A 3D reconstruction (using shaded surface display) of an extracted liver surface with an transplanted tumor...

PTC percutaneous transhepatic cholangiography SSD shaded surface display... 

Multi-phasic multidetector CT allows, in a single examination, a comprehensive evaluation of potential liver donors and of graft recipients. 3D-CTA with maximum intensity projection, multiplanar reconstructions, shaded surface display, and volume rendering techniques has become a strong competitor for DSA. The new development of multislice CT (MSCT) allows scan times fast enough to image the liver during a pure arterial phase of contrast opacification. This offers the possibility of 3D CTA for a variety of clinical applications. 

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