Image quality improvements in volume rendering

1996 ◽  
pp. 87-92 ◽  
Author(s):  
Jeroen Terwisscha van Scheltinga ◽  
Marco Bosma ◽  
Jaap Smit ◽  
Steven Lobregt
Keyword(s):  
Image Quality ◽  
Volume Rendering ◽  
Quality Improvements

scholarly journals Investigations on infrared-channel-image quality improvements for multispectral imaging

2018 ◽  
Vol 1044 ◽  
pp. 012039
Author(s):  
M. Rosenberger ◽  
C. Zhang ◽  
R. Celestre ◽  
G. Notni
Keyword(s):  
Image Quality ◽  
Multispectral Imaging ◽  
Quality Improvements ◽  
Channel Image ◽  
Infrared Channel

scholarly journals Echo Planar Diffusion-Weighted Imaging: Possibilities and Considerations with 12- and 32-Channel Head Coils

2012 ◽  
Vol 2 ◽  
pp. 31 ◽  
Author(s):  
John N Morelli ◽  
Megan R Saettele ◽  
Rajesh A Rangaswamy ◽  
Lan Vu ◽  
Clint M Gerdes ◽  
...  
Keyword(s):  
Image Quality ◽  
Parallel Imaging ◽  
Brain Magnetic Resonance Imaging ◽  
Single Shot ◽  
Quality Improvements ◽  
Planar Imaging ◽  
Diffusion Weighted ◽  
Resolution Imaging ◽  
Echo Planar ◽  
Parallel Imaging Acceleration

Interest in clinical brain magnetic resonance imaging using 32-channel head coils for signal reception continues to increase. The present investigation assesses possibilities for improving diffusion-weighted image quality using a 32-channel in comparison to a conventional 12-channel coil. The utility of single-shot (ss) and an approach to readout-segmented (rs) echo planar imaging (EPI) are examined using both head coils. Substantial image quality improvements are found with rs-EPI. Imaging with a 32-channel head coil allows for implementation of greater parallel imaging acceleration factors or acquisition of scans at a higher resolution. Specifically, higher resolution imaging with rs-EPI can be achieved by increasing the number of readout segments without increasing echo-spacing or echo time to the degree necessary with ss-EPI — a factor resulting in increased susceptibility artifact and reduced signal-to-noise with the latter.

scholarly journals Image quality improvements in C-Arm CT (CACT) for liver oncology applications: Preliminary study in rabbits

2013 ◽  
Vol 22 (5) ◽  
pp. 297-303 ◽  
Author(s):  
Vania Tacher ◽  
Nikhil Bhagat ◽  
Pramod P. Rao ◽  
MingDe Lin ◽  
Dirk SchÄfer ◽  
...  
Keyword(s):  
Image Quality ◽  
Quality Improvements ◽  
Preliminary Study

PROJECTIVE VOLUME RENDERING BY EXCLUDING OCCLUDED VOXELS

2005 ◽  
Vol 05 (02) ◽  
pp. 413-431
Author(s):  
WENCHENG WANG ◽  
HANQIU SUN ◽  
ENHUA WU
Keyword(s):  
Image Quality ◽  
Volume Rendering ◽  
Experimental Results ◽  
New Method ◽  
Ray Casting ◽  
Exclusion Problem ◽  
Data Volume ◽  
Projection Approach ◽  
Set Up

In volume rendering, an important issue in acceleration is to reduce the calculations for occluded voxels. Although this issue has been addressed in the ray casting approach, it is difficult to apply the idea to the projection approach due to uncertain termination conditions. In this paper, we propose a new method to effectively address the exclusion problem in the projection approach, so the rendering process can be accelerated without impairing the rendered image quality. In the rendering process, this new method employs the dynamic screen technique to manage the pixels whose accumulated opacity has not reached 1.0. A ray-cast link at each pixel is set up to record the rendered voxels for the corresponding ray cast from the pixel to intersect. According to the rendered voxels covering the pixels whose accumulated opacity value is below 1.0, visible voxels are selected to render from front to back by the neighboring relationship between the rendered voxels and the voxels to be rendered. Thus, the occluded voxels are dynamically excluded from the loading and rendering processes accurately. Our proposed method can be in general applied to both parallel and perspective projections, using regular and irregular volume datasets. Our experimental results showed that the proposed method can significantly accelerate volume rendering if the data volume has a high percentage of occluded voxels. This method can also perform fairly efficiently for the expensive shading calculations if requested in volume rendering.

Standardized volume-rendering of contrast-enhanced renal magnetic resonance angiography

2005 ◽  
Vol 46 (5) ◽  
pp. 497-504 ◽  
Author(s):  
Ö. Smedby ◽  
R. Öberg ◽  
B. Åsberg ◽  
H. Stenström ◽  
P. Eriksson
Keyword(s):  
Magnetic Resonance ◽  
Image Quality ◽  
Magnetic Resonance Angiography ◽  
Volume Rendering ◽  
Maximum Intensity Projection ◽  
Data Set ◽  
3D Data ◽  
Contrast Enhanced ◽  
Better Than ◽  
Good Agreement

Purpose: To propose a technique for standardizing volume-rendering technique (VRT) protocols and to compare this with maximum intensity projection (MIP) in regard to image quality and diagnostic confidence in stenosis diagnosis with magnetic resonance angiography (MRA). Material and Methods: Twenty patients were examined with MRA under suspicion of renal artery stenosis. Using the histogram function in the volume-rendering software, the 95th and 99th percentiles of the 3D data set were identified and used to define the VRT transfer function. Two radiologists assessed the stenosis pathology and image quality from rotational sequences of MIP and VRT images. Results: Good overall agreement (mean κ = 0.72) was found between MIP and VRT diagnoses. The agreement between MIP and VRT was considerably better than that between observers (mean κ = 0.43). One of the observers judged VRT images as having higher image quality than MIP images. Conclusion: Presenting renal MRA images with VRT gave results in good agreement with MIP. With VRT protocols defined from the histogram of the image, the lack of an absolute gray scale in MRI need not be a major problem.

scholarly journals Optimization of Breast Tomosynthesis Visualization through 3D Volume Rendering

2020 ◽  
Vol 6 (7) ◽  
pp. 64
Author(s):  
Ana M. Mota ◽  
Matthew J. Clarkson ◽  
Pedro Almeida ◽  
Nuno Matela
Keyword(s):  
Image Quality ◽  
Volume Rendering ◽  
Digital Breast Tomosynthesis ◽  
Data Set ◽  
Breast Tomosynthesis ◽  
Sampling Distance ◽  
Visualization Toolkit ◽  
Time Required ◽  
3D Volume ◽  
3D Volume Rendering

3D volume rendering may represent a complementary option in the visualization of Digital Breast Tomosynthesis (DBT) examinations by providing an understanding of the underlying data at once. Rendering parameters directly influence the quality of rendered images. The purpose of this work is to study the influence of two of these parameters (voxel dimension in z direction and sampling distance) on DBT rendered data. Both parameters were studied with a real phantom and one clinical DBT data set. The voxel size was changed from 0.085 × 0.085 × 1.0 mm3 to 0.085 × 0.085 × 0.085 mm3 using ten interpolation functions available in the Visualization Toolkit library (VTK) and several sampling distance values were evaluated. The results were investigated at 90º using volume rendering visualization with composite technique. For phantom quantitative analysis, degree of smoothness, contrast-to-noise ratio, and full width at half maximum of a Gaussian curve fitted to the profile of one disk were used. Additionally, the time required for each visualization was also recorded. Hamming interpolation function presented the best compromise in image quality. The sampling distance values that showed a better balance between time and image quality were 0.025 mm and 0.05 mm. With the appropriate rendering parameters, a significant improvement in rendered images was achieved.

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