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A new SPECT/CT reconstruction algorithm: reliability and accuracy in clinical routine for non-oncologic bone diseases

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EJNMMI RESEARCH 2018年第1期8卷 14-14页

作者： Delcroix, Olivier Robin, Philippe Gouillou, Maelenn Le Duc-Pennec, Alexandra Alavi, Zarrin Le Roux, Pierre-Yves Abgral, Ronan Salaun, Pierre-Yves Bourhis, David Querellou, Solene CHRU Hosp Morvan Nucl Med Dept Brest France CHRU Brest Brest France EA 3878 GETBO IFR 148 Serv Med Nucl Brest France Univ Bretagne Occidentale Brest France Brest Med Univ Hosp Inserm CIC 1412 Brest France Univ Hosp Nucl Med Dept Blvd Tanguy Prigent F-29200 Brest France

Background: xSPECT Bone (R) (xB) is a new reconstruction algorithm developed by Siemens (R) in bone hybrid imaging (SPECT/CT). A CT-based tissue segmentation is incorporated into SPECT reconstruction to provide SPECT images with bone anatomy appearance. The objectives of this study were to assess xB/CT reconstruction diagnostic reliability and accuracy in comparison with Flash 3D (R) (F3D)/CT in clinical routine. Two hundred thirteen consecutive patients referred to the Brest Nuclear Medicine Department for non-oncological bone diseases were evaluated retrospectively. Two hundred seven SPECT/CT were included. All SPECT/CT were independently interpreted by two nuclear medicine physicians (a junior and a senior expert) with xB/CT then with F3D/CT three months later. Interobserver agreement (IOA) and diagnostic confidence were determined using McNemar test, and unweighted Kappa coefficient. The study objectives were then re-assessed for validation through > 18 months of clinical and paraclinical follow-up. Results: No statistically significant differences between IOA (xB) and IOA F3D were found (p = 0.532). Agreement for xB after categorical classification of the diagnoses was high (K (xB) = 0.89 [95% CI 0.84 -0.93]) but without statistically significant difference F3D (K (proves 3D) = 0.90 [95% CI 0.86 -0.94]). Thirty-one (14.9%) inter-reconstruction diagnostic discrepancies were observed of which 21 (10.1%) were classified as major. The follow-up confirmed the diagnosis of F3D in 10 cases, xB in 6 cases and was non-contributory in 5 cases. Conclusions: xB reconstruction algorithm was found reliable, providing high interobserver agreement and similar diagnostic confidence to F3D reconstruction in clinical routine.

关键词： SPECT/CT Bone diseases Diagnostic accuracy Scintigraphy xSPECT Bone (R) reconstruction algorithm

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Backprojection reconstruction algorithm Using Order Statistic Filters In Breast Tomosynthesis

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ACTA CYBERNETICA 2009年第1期19卷 5-15页

作者： Csernetics, Laszlo

Breast cancer is the most common cancer type and one of the leading cause of death among women. It has been recognized over the years that preventing the disease is the most powerful weapon, and the implementation of screening mammography has had significantly reduced the death rate. However, it is also proven that conventional mammography does not detect approximately 30% of breast cancers. Inventing new imaging technologies for the earlier detection of breast cancer is vital and is in the center of many ongoing studies. There are several new techniques using different imaging modalities that are under investigation. The most promising is the breast tomosynthesis, an advanced x-ray application that addresses the problem of structure superimposition, one of the major deficiencies of 2D mammography, by reconstructing a range of slices providing additional 3-dimensional information of the breasts. Our goal is to investigate and develop reconstruction algorithms that fit into the new mathematical model of tomosynthesis used in mammography. In this paper we show a backprojection reconstruction technique that is especially well-suited for the problem in question. This algorithm is capable to produce contrast-enhanced slices of the breast by taking only the projections that most probably hold the "important" information of the targeted lesions, ignoring part of the projections. This statistical approach also offers a good noise management performance, as a fortunate side-effect. After discussing the algorithm we publish the results of the comparison of this technique with other popular methods of the algorithm-family. We also look out the strict boundaries of the work done suggesting improvements of the reconstruction algorithm.

关键词： breast tomosynthesis mammography breast cancer reconstruction algorithm

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A reconstruction algorithm for electrical impedance tomography data collected on rectangular electrode arrays

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IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING 1999年第11期46卷 1379-1386页

作者： Mueller, JL Isaacson, D Newell, JC Rensselaer Polytech Inst Dept Math Sci Troy NY 12180 USA Rensselaer Polytech Inst Dept Biomed Engn Troy NY 12180 USA

A three-dimensional reconstruction algorithm in electrical impedance imaging is presented for determining the conductivity distribution beneath the surface of a medium, given surface voltage data measured on a rectangular array of electrodes. Such an electrode configuration may be desirable for using electrical impedence tomography to detect tumors in the human breast. The algorithm is based on linearizing the conductivity about a constant value. Here, me describe a simple implementation of the algorithm on a four-electrode-by-four-electrode array and the reconstructions obtained from numerical and experimental tank data. The results demonstrate significantly better spatial resolution in the plane of the electrodes than with respect to depth.

关键词： electrical impedance tomography (EIT) reconstruction algorithm rectangular electrode array

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Accuracy of coronary artery calcium scoring with tube current reduction by 75%, using an adaptive iterative reconstruction algorithm

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BRITISH JOURNAL OF RADIOLOGY 2018年第1084期91卷 20170678页

作者： Luhur, Reny Schuijf, Joanne D. Mews, Jurgen Blobel, Jorg Ham, Bernd Lembcke, Alexander Charite Dept Radiol Campus Charite Mitte Berlin Germany Toshiba Med Syst Europe BV Ctr Med Res & Dev Europe Zoetermeer Netherlands

Objective: To assess the accuracy of an iterative reconstruction (IR) technique for coronary artery calcium scoring with reduced radiation dose. Methods: 163 consecutive patients underwent twofold scanning by 320-row detector CT at 120 kVp. A low-dose scan at 25% tube current but with standard scan length (14 cm) was followed by a standard dose scan with routine tube current but reduced scan length (10 cm). Reduced dose images were constructed using filtered back-projection (FBP) and IR (adaptive iterative dose reduction in three dimensions). The standard dose scan reconstructed with FBP served as the gold standard for comparisons. Image noise and Agatston coronary calcium scores were determined and compared between the groups. Results: Compared with FBP at standard dose, noise at reduced dose increased markedly with FBP but remained low with IR. Mean Agatston score with FBP at reduced dose showed a significant increase as compared with FBP at standard dose. No significant difference was observed when applying IR at reduced dose. At reduced dose, 38 (23.3%) patients were reassigned to a different cardiovascular risk category with FBP but only 8 (4.9%) with IR. Out of 47 patients with a zero Agatston score, 15 patients (319%) were false-positive with FBP at reduced dose, but no false positives were found with IR. Conclusion: IR allows accurate coronary artery calcium scoring with a radiation dose reduced by 75%. Advances in knowledge: The application of adaptive iterative dose reduction in three dimensions allows the maintenance of accurate Agatston scores and risk stratification at significantly reduced tube current, thus reducing the patient's exposure to ionizing radiation.

关键词： reconstruction algorithm Radiation Dosage tube current Iterative Coronary Calcium Score

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Diagnostic value of iterative reconstruction algorithm in low kV CT angiography (CTA) with low contrast medium volume for transcatheter aortic valve implantation (TAVI) planning: image quality and radiation dose exposure

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BRITISH JOURNAL OF RADIOLOGY 2018年第1092期91卷 20170802-20170802页

作者： Franzesi, Cammillo R. Talei Ippolito, Davide Riva, Luca Fior, Davide Cangiotti, Cecilia Sironi, Sandro Sari Gerardo Hosp Dept Diagnost Radiol Monza Italy Univ Milano Bicocca Sch Med Dept Diagnost Radiol Monza Italy Papa Giovanni XXIII Hosp Dept Diagnost Radiol Bergamo Italy

Objective: To evaluate image quality and radiation dose exposure of low-kV (100 kV) and low contrast medium (CM) volume CT angiography (CTA) in patients candidate to Transcatheter Aortic Valve Implantation (TAVI), in comparison with standard CTA protocol. Methods: 79 patients candidate for TAVI were prospectively enrolled in this study and examined with 256-MDCT. 42 patients were evaluated using study-group protocol (100 kV;whole-body retrospective ECG-gating;with 50 ml of CM;iterative reconstruction algorithm) while 37 patients underwent a standard CTA study (120 kV;ECG-gating for chest;100 ml of CM;FBP reconstruction). Overall image quality was evaluated using a 4-point scale. Vascular enhancement (HU) was then assessed in each patient by manually drawing multiple ROIs in lumen of 7 segments of the whole aorta. The radiation dose exposure of both groups was calculated and all data were compared and statistically analyzed. Results: On low-kV protocol, higher mean attenuation values were achieved in all the measurements as compared to standard protocol. There were no significant differences in the image quality evaluation in both groups. Mean radiation dose value of study group was significantly lower than in control group (reduction of 20%). Conclusion: Low kV and low CM volume CTA protocols allow TAVI planning to be carried out with high quality images and a significant reduction in the radiation dose as compared to the standard CTA protocol. Advances in knowledge: Low-kV CTA for pre-operative assessment of patients candidates for TAVI, permits to achieve a significant reduction of radiation dose exposure and contrast medium volume, reducing the risk of contrast induced nephropathy.

关键词： CENTRAL TRAINING ACADEMY diagnostic value Computed Tomography Angiography Image quality Radiation Dosage reconstruction algorithm

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90-kVp low-tube-voltage CT pulmonary angiography in combination with advanced modeled iterative reconstruction algorithm: effects on radiation dose, image quality and diagnostic accuracy for the detection of pulmonary embolism

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BRITISH JOURNAL OF RADIOLOGY 2018年第1088期91卷 20180269-20180269页

作者： Leithner, Doris Gruber-Rouh, Tatjana Beeres, Martin Wichmann, Julian L. Mahmoudi, Scherwin Martin, Simon S. Lenga, Lukas Albrecht, Moritz H. Booz, Christian Vogl, Thomas J. Scholtz, Jan-Erik Univ Hosp Frankfurt Dept Diagnost & Intervent Radiol Frankfurt Germany Mem Sloan Kettering Canc Ctr Dept Radiol Breast Imaging Serv 1275 York Ave New York NY 10021 USA Harvard Med Sch Massachusetts Gen Hosp Dept Radiol Cardiac MR PET CT Program Boston MA USA

Objective: To evaluate low-tube-voltage 90-kVp CT pulmonary angiography (CTPA) with advanced modeled iterative reconstruction algorithm (Admire) compared to 120-kVp equivalent dual-energy (DE) acquisition with regards to radiation exposure, image quality and diagnostic accuracy for pulmonary embolism (PE) assessment. Methods: CTPA studies of 40 patients with suspected PE (56.7 +/- 16.3 years) performed on a third-generation 192-slice dual-source CT scanner were retrospectively included. 120-kVp equivalent linearly-blended (60% 90-kVp, 40% 150-kVp) and 90-kVp images were reconstructed. Attenuation and noise of the pulmonary trunk were measured to calculate contrast-to-noise ratios (CNR). Three radiologists assessed the presence of central and segmental PE and diagnostic confidence. Interobserver agreement was calculated using intraclass correlation coefficient (ICC). Radiation exposure was assessed as effective dose (ED). Results: Pulmonary trunk CNR values were significantly increased in 90-kVp compared to linearly-blended series (15.4 +/- 6.3 vs 11.3 +/- 4.6, p < 0.001). Diagnostic accuracy for PE assessment was similar in both series with excellent interobserver agreement (p = 0.48;ICC, 0.83;p = 0.48). Overall confidence for PE assessment was rated excellent for both series with a significant advantage for linearly-blended series (p < 0.001;4.1 vs 3.8). ED was reduced by 37.2% with 90-kVp compared to 120-kVp equivalent image series (1.1 +/- 0.6 vs 1.7 +/- 0.7 mSv, p < 0.001). Conclusion: 90-kVp CTPA with Admire provided increased quantitative image quality with similar diagnostic accuracy and confidence for PE assessment compared to 120-kVp equivalent acquisition, while radiation dose was reduced by 37.2%. Advances In knowledge: 90-kVp CTPA with an advanced iterative reconstruction algorithm results in excellent image quality and reduction of radiation exposure without limiting diagnostic performance.

关键词： reconstruction algorithm diagnosis quality/standard Radiation Dosage accuracy test Pulmonary Embolism Image quality Iterative pulmonary angiogram X-Ray Computed Tomography

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A FAST IMAGE-reconstruction algorithm FOR ELECTRICAL-IMPEDANCE TOMOGRAPHY

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PHYSIOLOGICAL MEASUREMENT 1994年第2A期15卷 A115-A124页

作者： KUZUOGLU, M LEBLEBICIOGLU, K IDER, YZ Dept. of Electr. Eng. Middle East Tech. Univ. Ankara Turkey

In this paper, we propose a fast algorithm for the reconstruction of the conductivity perturbation DELTAsigma about a known conductivity variation sigma0. The method is based on the minimization of a quadratic functional subject to linear constraints, where the existence of a unique solution is guaranteed. The algorithm developed for this purpose is iterative and each iteration is composed of a simple matrix multiplication. The validity of this method is illustrated with several examples.

关键词： impedance Tomography image reconstruction Iterative Fasting conductivity iterative methods Delta sigma modulation reconstruction algorithm reconstructions algorithms Writers Matrix multiplication

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A Computationally Efficient reconstruction algorithm for Circular Cone-Beam Computed Tomography Using Shallow Neural Networks

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JOURNAL OF IMAGING 2020年第12期6卷 135-135页

作者： Lagerwerf, Marinus J. Pelt, Daniel M. Palenstijn, Willem Jan Batenburg, Kees Joost Ctr Wiskunde & Informat Sci Pk 123 NL-1098 XG Amsterdam Netherlands Leiden Univ Leiden Inst Adv Comp Sci NL-2333 CA Leiden Netherlands

Circular cone-beam (CCB) Computed Tomography (CT) has become an integral part of industrial quality control, materials science and medical imaging. The need to acquire and process each scan in a short time naturally leads to trade-offs between speed and reconstruction quality, creating a need for fast reconstruction algorithms capable of creating accurate reconstructions from limited data. In this paper, we introduce the Neural Network Feldkamp-Davis-Kress (NN-FDK) algorithm. This algorithm adds a machine learning component to the FDK algorithm to improve its reconstruction accuracy while maintaining its computational efficiency. Moreover, the NN-FDK algorithm is designed such that it has low training data requirements and is fast to train. This ensures that the proposed algorithm can be used to improve image quality in high-throughput CT scanning settings, where FDK is currently used to keep pace with the acquisition speed using readily available computational resources. We compare the NN-FDK algorithm to two standard CT reconstruction algorithms and to two popular deep neural networks trained to remove reconstruction artifacts from the 2D slices of an FDK reconstruction. We show that the NN-FDK reconstruction algorithm is substantially faster in computing a reconstruction than all the tested alternative methods except for the standard FDK algorithm and we show it can compute accurate CCB CT reconstructions in cases of high noise, a low number of projection angles or large cone angles. Moreover, we show that the training time of an NN-FDK network is orders of magnitude lower than the considered deep neural networks, with only a slight reduction in reconstruction accuracy.

关键词： tomography circular cone-beam CT machine learning neural network multilayer perceptron Feldkamp-Davis-Kress (FDK) reconstruction algorithm

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Superiorized polyenergetic reconstruction algorithm for reduction of metal artifacts in CT images

Superiorized polyenergetic reconstruction algorithm for redu...

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IEEE Nuclear Science Symposium

作者： T. Humphries A. Gibali School of STEM University of Washington Bothell Department of Mathematics ORT Braude College

ISBN: (纸本)9781538622834

Artifacts caused by metal objects such as dental fillings, hip implants, and coronary stents are a significant source of error in many CT scans. These artifacts are caused by numerous factors, including beam hardening, noise, photon starvation, partial volume and exponential edge gradient effects, and scatter. We propose an iterative algorithm for CT image reconstruction which reduces these artifacts. The algorithm does so by (1) accurately modeling polyenergetic X-ray data, (2) statistically weighting the X-ray data to reduce the effect of noisy measurements, and (3) incorporating total variation (TV) as a secondary objective. The recently proposed superiorization methodology provides a solid mathematical foundation for our approach. Our numerical experiments indicate that all three of these features of the algorithm play an important role in reducing metal artifacts.

关键词： Artifacts Metal Artifact reconstruction algorithm X-ray data Error Sources Metals X-Ray Computed Tomography image reconstruction Iterative algorithms

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Compressed Sensing MRI reconstruction algorithm Based on Contourlet Transform and Alternating Direction Method

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JOURNAL OF ELECTRICAL AND COMPUTER ENGINEERING 2015年第1期2015卷 175231.1-175231.5页

作者： Hu, Zhenyu Wang, Qiuye Ming, Congcong Wang, Lai Hu, Yuanqing Zou, Jian Yangtze Univ Sch Informat & Math Wuhan 434020 Hubei Peoples R China

Compressed sensing (CS) based methods have recently been used to reconstruct magnetic resonance (MR) images from undersampled measurements, which is known as CS-MRI. In traditional CS-MRI, wavelet transform can hardly capture the information of image curves and edges. In this paper, we present a new CS-MRI reconstruction algorithm based on contourlet transform and alternating direction method (ADM). The MR images are firstly represented by contourlet transform, which can describe the images' curves and edges fully and accurately. Then the MR images are reconstructed by ADM, which is an effective CS reconstruction method. Numerical results validate the superior performance of the proposed algorithm in terms of reconstruction accuracy and computation time.

关键词： images computational time delta modulation Compressed sensing profile transformation ACTION DESCRIPTION MEMORANDA reconstruction algorithm

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