Welcome to VIDA® (Spanish for life), a comprehensive package for the manipulation, display, and analysis of multidimensional image data sets. Physiologic-based research has traditionally involved highly invasive techniques which may alter the very function being studied. Since the first dynamic volumetric studies were done in the early 1980's on the Dynamic Spatial Reconstructor (DSR), there has been a surge of interest in volumetric and dynamic imaging using a number of tomographic techniques. Knowledge gained in handling DSR image data has been transferred to other volumetric imaging and dynamic imaging quantitation including cine and spiral CT, MR, and PET which led to our development of VIDA®.

VIDA® is written in C, runs under the UNIX operating system, and uses the XView toolkit to conform to the Open Look graphical user interface specification. VIDA®'s shared memory structure allows for the manipulation of multiple image data sets simultaneously. The windowing environment allows execution of multiple processes at once. Available programs include: orthogonal sectioning, oblique sectioning, volume rendering, surface rendering, region of interest analysis, conventional cardiac mechanics analysis, homogeneous strain analysis, tissue blood flow evaluation, interactive image segmentation and editing, algebraic image manipulation, and more. VIDA® is built modularly, allowing new programs to be developed and integrated easily. An emphasis has been placed upon image quantitation for the purpose of physiological evaluation.

Following is a brief tour highlighting the features and applications of VIDA® and its modules.


Visualizing Image Data



The Visualization modules are used for viewing image data sets in 2-D, 3-D, or dynamically (movies). One can view a volumetric data set in a transverse, sagittal, coronal, or oblique orientation. In particular, the Orthogonal Sections Display (OSD) allows you to display images on top of one another, side by side, or within a region of the screen for comparison. Oblique Sections Display (OBL) allows you to extract slices at any arbitrary orientation. You can create 3- dimensional displays of organs such as the heart, lungs,and brain with Volume Render (VR) or Surface Render (SR). Both VR and SR also allow you to make movies rotating and magnifying the organ.You can rapidly display images and movies created with the Volume Render and Surface Render programs using the Movie Viewer.


Analyzing Images


The Analysis modules can be used for making various regional and global measurements. For instance, Region of Interest (ROI) is designed for interactive image quantization, one of the current strong points of VIDA®. Several regions of various types can be created on a slice by using the mouse buttons and the cursor. Each region type has statistics and graphics options associated with it. Once regions have been defined, regional statistics (mean intensity, area, pixel count, length, etc.) can be extracted and stored as text files. Time-intensity plots and other graphs can also be generated for single or multiple regions. All defined regions can be saved to hard disk as .roi files and can be recalled later. Some VIDA® modules, such as Contour-Based Cardiac Mechanics, Homogeneous Strain Analysis, and Imatron Blood Flow, can read .roi files directly to aid further analysis.

Contour-Based Cardiac Mechanics computes regional ejection fractions, regional wall thickness, % wall thickening, etc. Homogeneous Strain Analysis was developed specifically to evaluate regional myocardial strain non-invasively through a magnetic imaging technique known as SPAMM by calculating the distortion of triangles generated from nodal points embedded within the myocardium. Tube Geometry Analysis (TGA) can be used for making 3-D geometric measurements, such as regional cross-sectional area, regional anterior-posterior length and lateral length of pre-segmented vessels or tubes. Image Based Perfusion Analysis (IBPA) automates the analysis of cine x-ray CT images, thereby allowing one to rapidly compute physiologic data such as regional blood flow, regional tissue, blood and air contents, mean transit times, etc. Color coded images of all physiologic parameters are generated and may be saved to disk.


Manipulating and Segmenting Image Data


The Image Manipulation modules are used for processing and manipulating image data. Included are various segmentation methods, interactive image editors, and automated analysis libraries. 2-D Segmentation makes manual image segmentation as flexible as possible. One can use 2-D Segmentation to distinguish particular structures from others within the same slice, such as the right vs. the left chambers of the heart. Segmentation is accomplished by altering the gray levels of structures so as to uniquely identify them. Algebraic Image Manipulation (AIM) can be used for performing image algebra by treating images as simple variables in an equation. Impromptu ( IMage PROcessing Module for Prototyping, Testing, and Utilizing image-analysis processes) provides a graphical user interface system for constructing, testing and executing automatic image analysis processes. Complex image analyses can be performed by constructing a sequence of simpler image processing and analysis functions.

Shape-Based Interpolation (MSBI) is used to form cubic voxels to maximize preservation of an organ's apparent original shape. Cubic-Voxel Interpolation (CVI) performs a similar task as Shape-Based Interpolation, while preserving an image's gray level information. By using MSBI or CVI before Surface Render or Volume Render, one reduces the stair step effect associated with thick slices. Vessel Segmentation can be used to segment connected vessels, such as airways or other major conduits, from three dimensional images.



File Manipulation

The File Manipulation modules provide tools for creating ANALYZE header files (.hdr) and reorganizing image data within a disk file. These modules may be needed before proceeding to use image data sets in VIDA®. For example an image data set cannot be loaded into VIDA® without an accompanying .hdr file and a header file needs to be created before proceeding. In other cases, it may be necessary to reorganize the sequence in which image slices are stored on hard disk, or flip the orientation of the slices.



Loading Data

Load Image Data allows you to load your image data from the computer hard disk into the computer shared memory (RAM). For historic reasons, we currently support the same file format used by another image processing packaged known as ANALYZE. Since this file format only supports four dimensional data, VIDA®'s Load ANALYZE Format module does not take full advantage of the 5 dimensional nature of the shared memory. We have plans to support ACR-NEMA and Interfile compatible file formats to take full advantage of shared memory capabilities. Tape to Disk translates vendor specific image formats into the ANALYZE file format currently used by VIDA®. This translation occurs while transferring the image data from tape to hard disk. Currently supported file formats include: Imatron, GE 8800 CT, GE 9800 CT, GE Signa MR, Siemens CT, and Siemens MR.



Changing the Display Colors and Contrast of Images and Overlays

Color Scales allows you to select a color scheme for displaying images in VIDA® modules. This module also allows you to window and level your image display and customize the colors used in various overlays in some VIDA® modules. The color scheme, window, and level can be changed at any time.



Managing Shared Memory

Memory Manager allows you to keep track of the image data in the shared memory and the amount of shared memory being used. This module has features for deleting items from shared memory and for saving items from shared memory to a disk file.



Exiting VIDA®

The Quit button allows you to exit VIDA®. When this option is selected, a popup panel will be displayed asking you to confirm the quit operation. If you have image data in shared memory, you will be warned that the image data in shared memory will be lost. If desired, at this time you may cancel the quit operation and save any data from shared memory to disk using the Memory Manager.





©1994-2005 Division of Physiologic Imaging, Dept. of Radiology, Univ. of Iowa


DPI Homepage | VIDA® | NLM | Contact Us | Search