PIPSpro ( Medical Image Processing and Display - made easy )

Introduction to PIPSpro
PIPSpro 3.2 is a 32-bit software system for displaying, enhancing, and analysing portal images, and is used in conjunction with all the commercial EPIDs on the market today, including the latest flat panel am-Si detectors. There are currently well over 150 installations in 23 countries and numerous publications in the literature describing its development and applications. PIPSpro provides numerous tools, routines and capabilities that are not available in the standard software provided by the EPID vendors. These include powerful image processing routines, flexible image display, easy-to-use image analysis tools, and a selection of image registration routines to identify field placement errors. Various measurement tools are included for statistical analysis, histograms, profiles, measurements and so on, as well as a comprehensive suite of tools for image comparison. Custom filters can be added, and user-supplied programs can be run from within PIPSpro.

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Hardware Requirements
PIPSpro will run on any IBM compatible computer operating under Microsoft Windows 9x/Me/NT/2000/XP. Up to 30 MB are required for the program and sample images, depending on the number of optional modules installed. At least 32MB RAM are required, except for optional module DRR which needs at least 128 MB RAM. A three-button mouse is preferred. Masthead Imaging provides only the software, and the customer provides the computer and O/S.

File Formats
PIPSpro can import images in a variety of image formats, and from all the commercial EPIDs (PortalVision Mk I, II and aS500, BeamviewPLUS, TheraView, SRI-100, iView, iViewGT, PORTpro) as well as film digitizers, CT, MRI, and any source of images in DICOM format.

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The PIPSpro System
PIPSpro has been designed as a basic system and a number of optional modules. This allows each customer to select only those modules that are of interest, and so keep the cost down. The optional modules currently available are quality control, dosimetry, movie display, image dewarping, stereotactic radiosurgery, and fast computation of DRRs. New modules are continuously under development. For example, an IMRT routine was recently added to the Movie module, as well as QuickAlign which permits the rapid registration of a whole series of portal images. Currently the following optional modules are available:
 

  Other modules are under development. 

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Image Processing and Enhancement
PIPSpro includes a wide variety of image processing routines for contrast enhancement, noise reduction, edge detection, and so on. Several of these routines have been developed specially for portal imaging and are not available in any other commercial software. For example, contrast enhancement using histogram modification (often called CLAHE) is available in all commercial EPID systems, but usually displays significant artefacts and distorts the field edge (and hence introduces errors into the registration process). PIPSpro has several routines which avoid these problems, including Adaptive Histogram Clip (AHC) which permits very high contrast enhancement but leaves the field edge unchanged. Sequences of operations can be saved as a macro for different types of portal images, treatment sites, and beam energies, and then recalled by a single mouse click when required. The image processing menu items are:
 

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Is image processing difficult?

Image processing is provided at two levels: fast and simple controls to permit a busy radiographer to examine, analyze and report on portal images as part of the normal clinical procedure, and more sophisticated routines for the experienced medical physicist or computer analyst who needs effective tools for detailed analysis of medical images, field placement errors, or dose distributions.

For the radiographer, standardized file import routines, image enhancement procedures, and image registration techniques make it possible to determine field placement errors with a minimum of time and effort. Results are displayed graphically as coloured "images of regret", as well as quantitatively in terms of field size, displacement, and rotation. Macros can be set up to perform even complex sequential processing steps by one or two clicks of the mouse. Results are saved in text files for later review or detailed analysis.

For the imaging scientist there is a wide variety of processing routines, all with variable parameters for optimizing their impact on different types and qualities of images. Measurements of lengths, angles, areas, profiles, histograms, pixel values and dose distributions are possible, and several methods for image registration are included to permit the selection of an optimal procedure for all types of situations. A general import routine accepts images from a wide variety of sources, including DICOM-3, and images can be saved in several formats, including compressed JPEG for reducing storage requirements.

For the specialist in medical imaging, numerous tools are provided, such as image comparison by visual, algebraic and boolean techniques. Screen, window and client capture are available, and either single images or multiple groups of images can be printed. For testing the registration software, a generalized image manipulation routine permits the preparation of test images with known placement errors in shift, rotation or scale. Optional modules provide facilities for quality control, dynamic viewing (movie mode) of sequences of images, dosimetry (mapping of image grey levels to dose), image dewarping, and more.

PIPSpro is an open system and user-supplied software can be called from a drop-down menu. Custom filters can be imported for general image processing and for image sharpening. PIPSpro can also be called from a command line instruction in another software system. Click here for answers to some Frequently Asked Questions.

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Analysis Tools
Tools are provided for viewing, measuring and analysing images. Some of these tools are listed below:
 

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Image Registration
Image registration is the key to determining field setup errors, which is the ultimate goal of portal imaging. PIPSpro includes several techniques for registering portal images with reference standards from the simulator, film, or DRRs. Automatic registration by fiducial points includes a warning if any of the delineated points are improperly positioned (the "Guilt check"). Out-of-plane patient rotations are indicated by the ratio of independent orthogonal scaling factors. Both of these features are available only in PIPSpro. Other registration techniques are interactive templating and automatic chamfer matching using fiducial points, templates, or contours. Field placement errors are displayed both numerically and graphically as "images of regret", providing the observer with a colored display of under- and over-dosed regions. In contrast to other commercial registration software, the images to be registered in PIPSpro may be of any relative scale, translation and rotation, and no pre-scaling or pre-alignment is required. A routine is provided for the generation of test image pairs to permit independent checking of the registration software.
 

A much simpler problem is matching two diagnostic images, such as CT or MRI, and this is done by chamfer matching a set of fiducial points, or templates, or contours. All image registration techniques result in the two images being displayed in the same co-ordinate system, scale and location, so that direct comparisons can be made using a variety of algebraic and Boolean procedures, as well as viewing tools such as CopyCat and THRU-VU.

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Quality Control for EPIDs
In addition to the PIPSpro software, Masthead Imaging also supplies the QC-3 test phantom. This quality control tool replaces the "Las Vegas" test tool used for several years by the commercial EPID vendors for their acceptance tests. The advantage of the QC-3 phantom is that it is easy to use and the analysis is entirely automatic. It is the only method commercially available that gives quantitative, objective, and reproducible measures of EPID image quality. More than 140 QC-3 phantoms are now in use world-wide, and it has become the defacto standard for quality assurance of EPIDs. It is invaluable during acceptance and commissioning to get "baseline" values for the resolution and noise. Since the same results are obtained with all the phantoms around the world, one can compare measured values for spatial and contrast resolution with other centers and with published data. The potential for gradual deterioration in image quality due to radiation damage in flat panel detector plates implies that a routine quantitative QA program is essential, not only to document and maintain image quality, but also to justify upgrades or replacements when required. The high resolution flat panel detectors have another interesting aspect that warrants careful attention. Since their internal spatial resolution is so high, the blurring effect of the finite linac focal spot becomes a significant factor. The focal spot size is easily monitored with the QC-3 phantom, and this parameter should be included in the routine QA program.

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Installation, training and technical support
PIPSpro is provided on a CD and installation is very simple. A very detailed User's Guide is provided which describes all operations of the program, and includes many tutorials and sample images to guide the new user through the basic steps. A 39-minute training video demonstrates how to run PIPSpro and is available in English or French. There is also a context-sensitive HELP routine, so that a click on Function Key F1 will show the appropriate Help instructions.
SeeDOS Ltd provides technical support by email, fax and telephone at no charge. Registered customers receive a password to the Downloads page on the appropriate website, where many useful files are available. Some customers have asked for the opportunity to guarantee future upgrades, and a more comprehensive Technical Support Program is available which provides a complimentary upgrade after one year, as well as a 50% discount on the cost of an in-house training session.

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Technical Notes
Many of the more complex or mathematical aspects of PIPSpro routines are explained in Technical Notes, and are included in the User's Guide.
 

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Whats New?

Additional information

For detailed PIPSpro information see :

Tools, Image Processing, Specifications, Applications, Publications, Users and FAQ(Frequently Asked Questions) .

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