In this paper, we improve a statistical iterative algorithm based on the minimization of the image total variation tv for sparse or limited projection views during ct image reconstruction. Advances in software and hardware have led to innovative algorithms and techniques that greatly reduce radiation and produce natural image impressions. The analytical reconstruction approaches, in general, try to formulate the solution in a. The basics for understanding what is iterative reconstruction. The evolution of image reconstruction for ctfrom filtered. Does iterative reconstruction lower ct radiation dose. Which is the best software for 3d reconstruction from ct cbct images.
Recent advances in computing power have enabled the development of software based methods for iterative image reconstruction ir in ct. Radiologists have been struggling to balance image noise with radiation dose in computed tomography ct scans for decades. Tomographic iterative gpubased reconstruction toolbox. When ct was developed by godfrey hounsfield in the 1970s, the original reconstruction algorithm he used was iterative reconstruction ir, where the software builds an image and then revises it with scores of reiterations to enhance image quality. Adaptive statistical iterative reconstruction asir, a reconstruction engine that sweeps noise from ct images, allows radiologists to cut dose by up to 66% in abdominal scans with no change in spatial or temporal resolution, according to dr. Iterative reconstruction ir processing of ct images the safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Software that improves image quality is on track to be a champion of ct dose reduction now and in the future. While mbir is the most recent of the iterative reconstruction technologies, top. However, in order to evaluate iterative reconstruction software, one must first understand the. The aquilion ct design focuses on the second method. Another example is to build neural networks by unrolling iterative reconstruction algorithms. Reducing ct radiation dose with iterative reconstruction. We put valuable information about the solution for your ct problems, so why not bookmark it.
I have used much software for 3d reconstruction and i have found that magics is the best tool for this work. Image quality is the main concern for reconstruction in comparison to conventional ct. Although new to ct, iterative reconstruction is widely used in pet and was used when ct was introduced 5. It explains ct reconstruction features of ct reconstruction software. Its focus is on iterative algorithms for improved image quality that have all been optimized to run on gpus including multigpus 1 for improved speed. For quite some time, iterative reconstruction has been heavily discussed in the ct community as a highly promising method to achieve significant dose reduction without compromising image quality. We used four ct systems equipped with a hybridstatistical ir hsir and a fullpartialadvanced modelbased ir mbir algorithms. The first ct scanners in the early 1970s already used iterative reconstruction algorithms. However, it is not intuitive and as any open source software there is no. Adaptive iterative reconstruction substantially reduces image quantum noise with no impact on spatial or contrast resolution. The purpose of this study was to compare the image noisereducing abilities of iterative model reconstruction imr with those of traditional filtered back projection fbp and statistical iterative reconstruction ir in abdominal computed tomography ct images. Recent studies with adaptive statistical iterative reconstruction, which combines a statistical form of iterative reconstruction with filtered back projectionreconstructed images, have reported the potential for a substantial decrease in radiation dose associated with chest and abdominal ct 9. This was the underlying principle for the development of adaptive iterative dose reduction 3d aidr 3d.
New iterative cone beam ct reconstruction software. Iterative reconstruction 101 imaging technology news. Implementation of iterative reconstruction offers the ability to minimize radiation exposure while preserving and, in some cases, improving image quality. The multiinstrument data analysis system midas tomography software originally designed for geophysical applications has been modified to cbct image reconstruction. Ct images are created from data and a computer uses software to reconstruct this data into a diagnosticquality image. An improved statistical iterative algorithm for sparse. Although new to ct, iterative reconstruction is widely used in pet and was used when ct was introduced. Klink t1, obmann v2, heverhagen j3, stork a4, adam g5, begemann p6. To assess the dose performance in terms of image quality of filtered back projection fbp and two generations of iterative reconstruction ir algorithms developed by the most common ct vendors. Overall, the use of exact projections and known ground truth is especially beneficial for benchmarking of iterative reconstruction algorithms. In recent years, iterative ct reconstruction method is drawing attention as a new ct reconstruction against backprojection ct reconstruction method. Midas is a software package first developed as an image reconstruction software for ionospheric imaging technique 8. One of the main distinguishers of aquilion ct is its. Impact of the depth of interaction in reconstruction of smallanimal spect data acquired with a spacevariable.
Ct image reconstruction tomoshop new generation ct. For example, in computed tomography an image must be reconstructed from. Tomoshop new generation ct reconstruction software. Listing a study does not mean it has been evaluated by the u. Evaluation of 15,000 computed tomography ct examinations to investigate if iterative reconstruction ir reduces sustainably radiation exposure. The advantage of iterative ct reconstruction method is reconstruction results with high image quality can be obtained even with few projected imagesraw data. In fact, it took until 2009 for the first iterative reconstruction algorithms to come commercially available and replace conventional filtered back projection.
Reducing ct radiation dose with iterative reconstruction algorithms. Limited view angle iterative ct reconstruction sherman j. Since then, this technique has caused a true hype in the field of radiology. At this lower patient dose level, if the greater image noise is modulated downward by adaptive statistical iterative reconstruction instead of using fbp, the lower. If you have problems with the reconstruction result from ct, if you are developing or modifying your ct system, and looking for adequate high quality ct reconstruction software, we can provide the best solution for you. Iterative reconstruction algorithms for computed tomography ct through total variation regularization based on piecewise constant assumption can produce accurate, robust, and stable results. Image reconstruction techniques are used to create 2d and 3d images from sets of 1d projections. Comparison of image quality from filtered back projection. Which is the best software for 3d reconstruction from ct cbct. Fast measurement times in industrial ct and lowdose dental ct imaging result in high noise levels in the projection images. Siemens safire iterative reconstruction protocol cleared. Basics of iterative reconstruction methods in computed tomography.
Iterative reconstruction in ct and mri and a bit of pet and spect je. Bouman a, sondre skatter b, mikhail kourinny b, and simon bedford c a purdue university, west lafayette, in, usa. Which is the best software for 3d reconstruction from ct. In contrast to idose 4, iterative model reconstruction aims at accounting for not only the noise behavior of the image but also the data statistics, image statistics. The toolbox is now being extended for medical imaging application in iterative cbct and the results are verified against commercial fdk results. Iterative reconstruction refers to an image reconstruction algorithm used in ct that begins with an image assumption, and compares it to real time measured values while making constant adjustments until the two are in agreement. A current limitation of iterative reconstruction, however, is the long computing time. The list of supported trajectories is long it includes sparse and limited angle ct for automatic xray inspection axi of pcbs, circular tomosynthesis for analysis of fiber composite layers, or linear tomosynthesis of wind turbine blades, for instance. Iterative reconstruction refers to iterative algorithms used to reconstruct 2d and 3d images in certain imaging techniques. Standard filtered back projection a and adaptive statistical iterative reconstruction asir b coronal multiplanar reformations from ct angiography at 2mm slice thickness show improved visualization of accessory left renal artery arrow on asir image. Cone beam computed tomography cbct provides a volumetric image reconstruction from tomographic projection data. Michigan image reconstruction toolbox mirt the michigan image reconstruction toolbox mirt is a collection of open source algorithms for image reconstruction and related imaging problems written in mathworks matlab language.
Modelbased iterative ct image reconstruction on gpus. Imr sets a new direction in ct image quality with industryleading lowcontrast resolution and virtually noisefree images. Radiation exposure from multidetector computed tomography ct has become a pressing public health concern in both lay and medical publications. The toolbox is now being extended for medical imaging application in iterative cbct and the results are verified against. In cbct reconstruction algorithms, iterative methods offer the potential to generate high quality images and would be an advantage especially for downsampling projection data. Fbp tuning parameters challenging to characterize performance. However, in order to evaluate iterative reconstruction software, one must first. View details of philips iterative model reconstruction.
Iterative reconstruction technique for reducing body. The efficient multigpubased module for iterative ct reconstruction delivers superior image quality with comparably short reconstruction times. This paper will focus on aidr 3d, its ease of use, and the benefits of an integrated, automated and adaptive design. High scan flexibility iterative reconstruction algorithms support virtually arbitrary ct scan trajectories. Information from 15,000 ct examinations was collected, including all aspects of the exams such as scan parameter. An adaptive shortcut which starts iterative reconstruction after a firstpass fbp reconstruction, adaptive statistical iterative reconstruction, can help shorten the longer reconstruction time of pure iterative reconstruction while maintaining much lower image noise than if the same raw data were reconstructed with fbp alone. Gpu petspect and ct reconstruction statistical iterative reconstruction research fields. Innovations in hardware and the reconstruction algorithm result in a reconstruction speed less than three minutes for the majority of reference protocols that allows modelbased benefits to be achieved in even the most demanding applications. Shefer philips healthcare, cleveland, usa abstract computed tomography ct scanner technology has progressed rapidly throughout the past. The semiautomated reconstruction workflow requires no knowledge about iterative reconstruction to obtain best reconstruction results. Midas is a software package first developed as an image reconstruction software for ionospheric imaging technique. Second, even if the software database is composed of several values of pitch, reconstruction thickness and reconstruction kernels, the results presented in.
If nothing happens, download github desktop and try again. The efficient multigpubased module for iterative ct reconstruction. Iterative reconstruction algorithms for computed tomography ct through total. Iterative model reconstruction is the secondgeneration ir algorithm introduced by philips healthcare in 2012. December, 2011 siemens announced its computed tomography ct iterative reconstruction algorithm safire sinogram affirmed iterative reconstruction has been cleared for domestic sale by the u. An interactive software was developed with the modeled 3d cat and the selected images using unity, version 5. Tigre is an opensource toolbox for fast and accurate 3d tomographic reconstruction for any geometry.
Iterative reconstruction is a reconstruction algorithm whereby image data are corrected with an assortment of models. Iterative reconstruction in ct evolves for lower dose, increased clarity diagnostic imaging. Aidr 3d iterative reconstruction canon medical systems usa. These reconstruction techniques form the basis for common imaging modalities such as ct, mri, and pet, and they are useful in medicine, biology, earth science, archaeology, materials science, and nondestructive testing. While mbir is the most recent of the iterative reconstruction technologies, top manufacturers offer their own software answers to the noise versus dose argument. But the competition just went up a notch or perhaps many notches with the recent fda approval of ge healthcares model based image reconstruction mbir technology, veo. This new generation of image reconstruction software and hardware allows for a robust reduction of radiation dose in ct. Comparison of image noise in 56yearold obese man at standarddose ct. However, computer speeds in the 1970s were so slow it took about 45. Iterative reconstruction in ct evolves for lower dose. Aquilion ct through innovative design of hardware and software. A current limitation of iterative reconstruction, however, is the.
Except for precision learning, using conventional reconstruction methods with deep learning reconstruction prior is also an alternative approach to improve the image quality of deep learning reconstruction. In tomophantom, the generated projection data are compatible with widelyused opensource tomographic reconstruction software. It is free software released under the gnu gplv2 intended for use in research and education. Rather than increase scanner power and xray tube output to maximize signal, aquilion ct minimizes noise to allow for dose reduction. Computed tomography ct image reconstruction is an important technique used in a variety of domains, including medical imaging, electron microscopy, non. There fore, a modified and computationally faster iterative reconstruction technique, adaptive statistical iterative reconstruction, was devel. Cera ct reconstruction and artifact reduction siemens. The reconstruction algorithm used is clearly important and should be carefully designed, developed and investigated before it can be applied clinically. This software was developed at the university of michigan by jeff fessler and his group.
870 1172 783 668 1257 904 1374 1581 700 849 1061 806 214 317 51 164 1320 299 45 536 299 1434 1085 1619 1581 629 515 353 985 328 880 623 1142 521 777