Week 12 - Post Processing Flashcards
-referred to as multiplanar reconstruction, image reformatting, image reformation
-computer program that can create coronal, sagittal and paraxial images from stack of continuous transverse axial scans
Multiplanar reformation
T/F
Most images are acquired in an axial format, head and extremities can be imaged in coronal
*transverse plane
True
T/F
The plane an image is acquired in depends on the patient positioning, not the way the gantry turns
True
Plane that passes through the body from anterior to posterior and divides the body into left and right
Sagittal
A plane that passes through the body from right to left, dividing the region into anterior and posterior sections
Coronal
T/F
An irregular(linear, curved), or oblique view can be reconstructed from a stack of contiguous transverse images
True
What are some advantages of reformatted images?
-enables visualization of specific structures in relation to surrounding structures
-determines extent of lesions or fracture
-helps localize lesions, bond fragments, foreign bodies
What is a disadvantage of reformatted images?
Loss of image detail
What are the 4 major steps of 3D imaging?
- Data acquisition
- Creation of 3D space
- Processing for 3D image display
- 3D image display
Tools such as windowing are computer programs that provide the observer-diagnostician with additional information to facilitate diagnosis
Visualization tools
*range from basic to advanced, have been implemented on graphic processing units (GPU)
What is the most used post processing technique?
Windowing
-allow the user to render various 3D images from the axial dataset
-3D rendering includes: SSD, VR, MIP, MinIP, cinematic rendering and global illumination
3D visualization tools
-provides detailed photorealistic visualization of high density objects, including contrast enhanced blood vessels, vascularized structures, tissues, organs and bones
Cinematic rendering
*movie
*common for stroke patients
-recent 3D/4D rendering technique that uses complex lighting and shading techniques to provide a more photorealistic image of patients anatomy
Global illumination
-technique based on volume data acquisition principles
-an application of 3D imaging and has become popular in the examination of circulatory system
Ex. 4D angio, vessel tracking, skull removal, multiple target volume
CT angiography (CTA)
-4th dimension of opacity instead of time and is based on VR technology
-changes in the opacity values of various tissues enables the observer to simultaneously visualize bone, soft tissue, vascular structures
-both foreground and background structures are visible
4D angio
Why is 4D angio preferred over conventional MIP techniques?
Visualization of aortic aneurysms, renal arteries, stents, carotid bifurcation
*MIP only allows the user to render only a selected volume data and does not require segmentation techniques
*4D angio - enhanced MIP
-allows the user to produce a set of MPR images, including curved MPR images for the entire vessel
-skull removing tool facilitates the subtraction of bones of the skull from the CTA image and allows the observer to visualize detailed images of vessels and soft tissue
Vessel tracking tool
-display all types of MPR images from the axial dataset in the axial, coronal, sagittal and oblique planes
MPR tools
Offer the following in any 3D rendering mode:
Window/level adjustment, volume of interest adjustment, scan info. Display, movie creation and playback, split screen presentation, zoom, measurements
Interactive visualization tools
-allows the user to view a large set of images very quickly
Cine visualization tools
-facilitate measurements such as distances, angles, areas, means, standard deviation, min/max voxel values, density value in HU, density histogram for particular ROI, volume of 3D objects
Advanced quantitative measurement tools
-allows user to combine images from different modalities
Multimodality image fusion tools
*advanced software needed
-include Voyager and 3D Navigator
-create 3D and 4D images of tubular structures and allow user to “fly though” the images of hollow organs - CT virtual endoscopy
Virtual reality visualization tools
