A newly adapted lowdose computed tomography ct technique called adaptive statistical iterative reconstruction asir can help radiologists reduce the already low radiation dose delivered during. Radiation exposure from multidetector computed tomography ct has become a pressing public health concern in both lay and medical publications. Second, because of its retrospective nature, images were reconstructed with fixed value of asir and asir v. Radiation dose consideration in kidney stone ct examinations. The spectral ct in which the energy dependence of the xray attenuation coefficient is utilized multiple parameters can be acquired by means of spectral ct techniques, such as monochromatic imaging, material decomposition images, spectral hu curve and effective atomic number, etc. The detection of focal liver lesions using abdominal ct. Impoved image reconstruction software for safer tomographic. The company says it reduces dose while maintaining image quality and can be implemented as a costeffective upgrade for existing lightspeed vct systems. Using asir, patient dose was reduced with high image clarity in the cardiac study.
The study showed that advanced ct reconstruction techniques such as asir tm or veo tm, combined with the isosmolar contrast agent, visipaque tm 270 or 320mgiml and low kvp, deliver equivalent. Cranial ct with adaptive statistical iterative reconstruction. Nov 17, 2015 the spectral ct in which the energy dependence of the xray attenuation coefficient is utilized multiple parameters can be acquired by means of spectral ct techniques, such as monochromatic imaging, material decomposition images, spectral hu curve and effective atomic number, etc. Ge healthcare jumped ahead of competitors in the race to cut patient dose with the commercial release in 2008 of its adaptive statistical iterative reconstruction asir, the first software to clean up ct images and, in the process, allow dramatic reductions up to 50% in patient radiation dose. However, selection of image reconstruction algorithm is crucial for obtaining high quality images. During a ct scan, youll be given orally or via injection a small dose of a radioactive solution that. This study characterizes dose reductions in clinical settings for ct examinations. Ct manufacturers during the 2010 radiological society of north america rsna meeting in december, all the major ct vendors introduced new doselowering software or highlighted worksinprogress. Ac, 2d axial imagessupine image using standarddose ct colonography with 50 mas and 0% adaptive statistical iterative reconstruction asir a, prone image using 25 mas and 0% asir b, and prone image using 25 mas and 40% asir c show asir reduces noise artifact to produce improved image.
And once again siemens healthineers has set the benchmark on low dose imaging with the introduction of the first rawdata based iterative reconstruction safire. Ct images from clinical paediatric abdominal ct examinations were reconstructed from raw data, i. The technique, called adaptive statistical iterative reconstruction asir by its developer, ge healthcare, reduces noise in the image, allowing a downward. Reconstruction software improves quality of lowdose ct. Iterative reconstruction ir algorithms have been adopted by medical centers in the past several years. Deep learning image reconstruction software can be used for head, whole body, cardiac, and vascular ct applications. Asir technique significantly reduces already low radiation.
Adaptive statistical iterative reconstruction asir technique is useful for reducing ct radiation dose and improving image quality. Ir has a potential to substantially reduce patient dose while maintaining or improving image quality. Volvicon is an advanced application for reconstruction of computed tomography ct, magnetic resonance mr, ultrasound, and xrays images. A consultation with a radiologist and a physicist should be made to. However, in order to evaluate iterative reconstruction software, one must first understand the. The mathematical basis for tomographic imaging was laid down by johann radon. The gsi feature on revolution ct is 510k pending at fda. Spiral acquisition and reconstruction with a digital flatpanel detector. Computer technology limited early scanners in their ability to perform the iterative reconstruction. Contrast media and ct image reconstruction from ge. Asir image reconstruction was selected for three different levels of blending 30%, 50%, and 70% hereafter, asir 30, asir 50, and asir 70, respectively at each of the four different radiation dose levels to obtain 12 asir image data sets.
Additionally, to establish whether radiomics from singleslice analysis undergo greater change than those from multislice analysis. Ct images have been reconstructed from raw data using filtered back projection fbp since the inception of the modality. This can help lower patient radiation dose by 3080 percent, according to the manufacturers, without compromising diagnostic image quality. The use of adaptive statistical iterative reconstruction. This software collects radiation dose data 1 directly from your ge healthcare ct scanner, then summarizes and presents the data via a web application. We compared 30% adaptive statistical iterative reconstruction and modelbased iterative reconstruction algorithms for the assessment of image quality of contrastenhanced ct of the neck. The evolution of image reconstruction for ctfrom filtered. Asir v differs from the earlier veo ct modelbased iterative reconstruction,2 in that it deemphasizes the system optics modeling, enabling reconstruction speed similar to fbp. Computed tomography ct offers a very important, noninvasive diagnostic tool, but the price of high image quality sometimes comes with a cost of high radiation dose. Impact of modelbased iterative reconstruction on image. The adaptive statistical iterative reconstructionv.
Iterative reconstruction 101 imaging technology news. Second, because of its retrospective nature, images were reconstructed with fixed value of asir and asirv. Adaptive statistical iterative reconstruction asir. Philips introduced its ingenuity ct, which features the companys new idose4 iterative reconstruction software. The purpose of this study was to evaluate the impact of an iterative reconstruction algorithm, asir, on imagequality measures in reduceddose head ct scans for adult patients. Asirv, adaptive statistical iterative reconstruction v. We aimed to evaluate a new modelbased iterative reconstruction mbirn algorithm either with spatial resolution and noise reduction balance mbir stnd or spatial resolution preference mbir rp20 for quantitative analysis of airway in lowdose chest computed tomography ct with a computeraided detection cad software, in comparison to adaptive statistical iterative. Computed tomography ct is a fast and accurate diagnostic tool that can be applied to the whole body. Asirv differs from the earlier veo ct modelbased iterative reconstruction,2 in that it deemphasizes the system optics modeling, enabling reconstruction speed similar to fbp. To safeguard patient health, there is great interest in ct radiationdose reduction.
Third, 2 different 1 for each irt scanners have been used, although the ct. The ge deep learning image reconstruction software for the revolution evo is substantially equivalent to the unmodified predicate device dlir reconstruction option for revolution family of ct systems. Which is the best software for 3d reconstruction from ct. Ge healthcare continues to focus on dosereducing ct options with its adaptive statistical iterative reconstruction asir technology, available on the ge discovery ct750 hd and the lightspeed vct. Dosewatch explore is a webbased, cloud deployed, introductory dose management software to track, analyze and report practicelevel data for ge healthcare ct systems. In clinical practice, the use of asir v may reduce ct patient dose depending on the clinical task, patient size, anatomical location and clinical practice.
The purpose of this study was to evaluate the impact of an iterativereconstruction algorithm, asir, on imagequality measures in reduceddose head ct scans for adult patients. Thinslice fbp asir statistical seconds a bit longer much longer. Ge healthcare goldseal refurbished optima ct660 128slice axial reconstruction for improved zaxis visualization. However, the conventional reconstruction technique has been filtered backprojection fbp. In fact, it took until 2009 for the first iterative reconstruction algorithms to come commercially available and replace conventional filtered back projection. Medical technology asir ct dose reduction vidant health. Castor is an opensource multiplatform project for 4d emission pet and spect and transmission ct tomographic reconstruction. A consultation with a radiologist and a physicist should be made to determine the appropriate dose to obtain diagnostic image quality for the particular clinical task. In the first day of this years isct symposium, iterative reconstruction was. Oct 30, 2018 the first ct scanners in the early 1970s already used iterative reconstruction algorithms. The ge asirv reconstruction option is an alternate ct image reconstruction option for ge ct systems to filtered back projection, the advanced ge iterative reconstruction software veo reconstruction option k103489 and the asir reconstruction option. A type of iterative reconstruction may reduce patient radiation dose from ct scans up to 65%, according to a study published in the september issue of the american journal of roentgenology. The aim was to evaluate the effect of adaptive statistical iterative reconstruction on the performance of computeraided detection cad for pulmonary nodules on garnetbased detector ct images. With characteristics between those of asir and veo, asir.
Asir, adaptive statistical iterative reconstruction. Mar 18, 2019 to investigate whether adaptive statistical iterative reconstruction asir, a hybrid iterative ct image reconstruction algorithm, affects radiomics feature quantification in primary colorectal cancer compared to filtered back projection. New levels of ct image performance and new levels in. Mbir reconstruction in ct produces diagnostic image quality and results in acceptable image noise and diagnostic confidence, reducing radiation dose by 2. However, in order to evaluate iterative reconstruction software. The objective of our study was to evaluate three commercially available iterative reconstruction ir algorithmsasir, idose, and safireand conventional filtered back projection fbp on image quality and radiation dose in kidney stone ct examinations. Interobserver agreement there was an excellent interobserver agreement between the three radiologists for lesion detection of both small and large focal liver lesions icc 0.
Quantitative analysis of airway tree in lowdose chest ct. The standard fbp algorithm operates on several fundamental assumptions about scanner geometry but is basically a compromise between reconstruction speed and image noise. Ring reduction compensates for the irregular response of the detector pixels during a ct scan. In our region, the optima ct660 is the first ct scanner with lowdose technology, and it helps demonstrate to patients our concern regarding patient dose and the environment. To investigate whether adaptive statistical iterative reconstruction asir, a hybrid iterative ct image reconstruction algorithm, affects radiomics feature quantification in primary colorectal cancer compared to filtered back projection. Tomographic reconstruction is a type of multidimensional inverse problem where the challenge is to yield an estimate of a specific system from a finite number of projections. This study aimed to investigate the impact of iterative reconstruction algorithms on the accuracy and precision of volume quantification with dose and slice thickness as additional variables. Ct image reconstruction tomoshop new generation ct. Ct reconstruction techniques for improved accuracy of lung. Modelbased iterative reconstruction and adaptive statistical. Mbir finds same nodules as asir, at fraction of dose.
The reconstruction technique first used in a clinical ct scanner was a type of iterative reconstruction ir called algebraic reconstruction technique 1, 2. Asir ct dose reduction what is asir ct dose reduction. Reducing the radiation dose for ct colonography using. Improved image quality is clinically desired for contrastenhanced ct of the neck. The dependence of noise reduction and of the nps have been investigated as a function of kernel, dose and slice thickness and comparison has been performed with asir. Aug 20, 2010 a new lowdose abdominal computed tomography ct technique called adaptive statistical iterative reconstruction asir can reduce the radiation dose associated with abdominal ct scans by 2366. Ct reconstruction techniques for improved accuracy of lung ct. The adaptive statistical iterative reconstructionv technique. 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 new lowdose abdominal computed tomography ct technique called adaptive statistical iterative reconstruction asir can reduce the radiation dose associated with abdominal ct scans by 2366. Selection of image reconstruction algorithm depending on target objects.
The adaptive statistical iterative reconstruction asir. 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 computer technology limited early scanners in their ability to perform the iterative reconstruction. Since then, this technique has caused a true hype in the field of radiology. Ges asir gains foothold in ct community diagnostic imaging. In conclusions, noise properties have been assessed for the new adaptive statistical iterative reconstruction, asir.
Repeated ct images were acquired from an anthropomorphic chest phantom with synthetic nodules 9. Asir is also helpful in improving ct image quality for obese patients. Reconstruct a complete 3d ct model that includes time and motion, creating a truly dynamic volumetric dataset. Benefits of asirv reconstruction for reducing patient. Lower dose ct reconstruction included filtered back projection b, adaptive statistical iterative reconstruction asir 40% c, asir v 30% d, asir v 50% e and asir v 70% f. The volume ct dose index for lower dose series was 4. Asir technique significantly reduces radiation dose. The optima ct660 with asir provides an opportunity to conduct a lowdose ct study. We aimed to evaluate a new modelbased iterative reconstruction mbirn algorithm either with spatial resolution and noise reduction balance mbir stnd or spatial resolution preference mbir rp20 for quantitative analysis of airway in lowdose chest computed tomography ct with a computeraided detection cad software, in comparison to adaptive. Since then, this technique has caused a true hype in the. This reconstruction technique is the advanced ge iterative reconstruction method. Adaptive statistical iterative reconstruction asir is a software package that allows your radiology team to reduce your exposure to radiation without sacrificing quality in a computed tomography ct scan. Lower dose ct reconstruction included filtered back projection b, adaptive statistical iterative reconstruction asir 40% c, asirv 30% d, asirv 50% e and asirv 70% f.
It gives features for exporting 3d surfaces or volume as. In this study, patients with solitary pulmonary nodules spn underwent dualphase scanning by low dose spectral ct. Adaptive statistical iterative reconstruction technique. A pilot study using lowdose spectral ct and asir adaptive. Pdf asir and asirv iterative reconstruction comparison. The ge asir v reconstruction option is an alternate ct image reconstruction option for ge ct systems to filtered back projection, the advanced ge iterative reconstruction software veo reconstruction option k103489 and the asir reconstruction option. Implementation of iterative reconstruction offers the ability to minimize radiation exposure while preserving and, in some cases, improving image quality. It is also designed to work for the majority of clinical modes on multiple ct products. Jun 21, 2010 a newly adapted lowdose computed tomography ct technique called adaptive statistical iterative reconstruction asir can help radiologists reduce the already low radiation dose delivered during. Iterative reconstruction ct radiology reference article.
Advancements in ct imaging processing software have helped improve the image quality from lowdose scans by eliminating noise. This platform is a scalable software providing both basic image reconstruction features for standard users and advanced tools for specialists in the reconstruction field, to develop, incorporate and assess their own methods in image. During a ct scan, youll be given orally or via injection a small dose of a radioactive solution. Adaptive statistical iterative reconstruction asir affects. The asir reconstruction algorithm is a promising technique for providing diagnostic quality ct images at significantly reduced radiation doses. The first ct scanners in the early 1970s already used iterative reconstruction algorithms. A notable example of applications is the reconstruction of computed tomography ct where crosssectional images. Jul 23, 20 radiation exposure from multidetector computed tomography ct has become a pressing public health concern in both lay and medical publications. May 18, 2011 ge healthcare showcased its asir adaptive statistical iterative reconstruction lowdose reconstruction technology, available on the ge discovery ct750 hd and lightspeed vct. According to nilesh shah, global chief marketing officer for ge healthcares ct business unit, asir is designed to reduce image noise without. Adaptive statistical iterative reconstruction technique for. The primary technique uses iterative image reconstruction.
Thus, 368 image series 16 image data sets in 23 patients were generated. V presents a more advanced noise and object modeling than asir, and it has implemented physics modeling. Using a 64section scanner, we analyzed 100 reduceddose adult head ct scans at 6. In clinical practice, the use of asirv may reduce ct patient dose depending on the clinical task, patient size, anatomical location and clinical practice.
Reconstruction software improves quality of lowdose ct scans this article appeared as the introduction to the ct dose reduction comparison chart. New adaptive statistical iterative reconstruction asir. 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. V is a recently released ir algorithm developed by ge.