1
|
Alpar O, Krejcar O, Dolezal R. Distribution-based imaging for multiple sclerosis lesion segmentation using specialized fuzzy 2-means powered by Nakagami transmutations. Appl Soft Comput 2021. [DOI: 10.1016/j.asoc.2021.107481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
2
|
Wen H, Zheng W, Li M, Li Q, Liu Q, Zhou J, Liu Z, Chen X. Multiparametric Quantitative US Examination of Liver Fibrosis: A Feature-engineering and Machine-learning Based Analysis. IEEE J Biomed Health Inform 2021; 26:715-726. [PMID: 34329172 DOI: 10.1109/jbhi.2021.3100319] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Quantitative ultrasound (QUS), which is commonly used to extract quantitative features from the ultrasound radiofrequency (RF) data or the RF envelope signals for tissue characterization, is becoming a promising technique for noninvasive assessments of liver fibrosis. However, the number of feature variables examined and finally used in the existing QUS methods is typically small, to some extent limiting the diagnostic performance. Therefore, this paper devises a new multiparametric QUS (MP-QUS) method which enables the extraction of a large number of feature variables from US RF signals and allows for the use of feature-engineering and machinelearning based algorithms for liver fibrosis assessment. In the MP-QUS, eighty-four feature variables were extracted from multiple QUS parametric maps derived from the RF signals and the envelope data. Afterwards, feature reduction and selection were performed in turn to remove the feature redundancy and identify the best combination of features in the reduced feature set. Finally, a variety of machine-learning algorithms were tested for classifying liver fibrosis with the selected features, based on the results of which the optimal classifier was established and used for final classification. The performance of the proposed MPQUS method for staging liver fibrosis was evaluated on an animal model, with histologic examination as the reference standard. The mean accuracy, sensitivity, specificity and area under the receiver-operating-characteristic curve achieved by MP-QUS are respectively 83.38%, 86.04%, 80.82% and 0.891 for recognizing significant liver fibrosis, and 85.50%, 88.92%, 85.24% and 0.924 for diagnosing liver cirrhosis. The proposed MP-QUS method paves a way for its future extension to assess liver fibrosis in human subjects.
Collapse
|
3
|
Alpar O. Nakagami imaging with related distributions for advanced thermogram pseudocolorization. J Therm Biol 2020; 93:102704. [PMID: 33077125 DOI: 10.1016/j.jtherbio.2020.102704] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 07/29/2020] [Accepted: 08/17/2020] [Indexed: 11/25/2022]
Abstract
Pseudocoloring algorithms embedded in the software of thermal cameras gradually colorize original intensity thermograms generated by detecting temperatures and contrast. Maximum and minimum based algorithms, however, executed by thresholding, applied to intensity thermograms for revealing and coloring the outliers instead. Although the common pseudocoloring protocols employed for general purposes may provide crucial information on the superficial contrast between radiation emitted by various sources; their common kernel is not sufficient for detecting and differentiating high radiated regions from surrounding areas, which is mandatory for recognition of abnormalities. Therefore, we propose novel imaging methodology based on Nakagami and related distributions, including gamma, Rayleigh, Weibull, chi-square and exponential, for enhancing thermal images and also for creating adequate discrimination. We initially define the boundaries of tumor and surrounding area in a synthetically generated breast thermogram already diagnosed as retroareolar tumor. Using Nakagami and transformations supported by mathematical foundations, we conducted several experiments to find the discrimination factor of the pseudocoloring techniques by calculating difference of average contrast between the tumor and the surrounding area. The performance is greatly encouraging that we achieved considerably better discrimination factor, designated for this study, up to 106.80 compared to the results of existing built-in pseudocolorization methods computed as 11.56.
Collapse
Affiliation(s)
- Orcan Alpar
- Center for Basic and Applied Research, Faculty of Informatics and Management, University of Hradec Kralove, Rokitanskeho 62, Hradec, Kralove, 50003, Czech Republic.
| |
Collapse
|
4
|
Zhou Z, Gao A, Zhang Q, Wu W, Wu S, Tsui PH. Ultrasound Backscatter Envelope Statistics Parametric Imaging for Liver Fibrosis Characterization: A Review. ULTRASONIC IMAGING 2020; 42:92-109. [PMID: 32100633 DOI: 10.1177/0161734620907886] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Early detection and diagnosis of liver fibrosis is of critical importance. Currently the gold standard for diagnosing liver fibrosis is biopsy. However, liver biopsy is invasive and associated with sampling errors and can lead to complications such as bleeding. Therefore, developing noninvasive imaging techniques for assessing liver fibrosis is of clinical value. Ultrasound has become the first-line tool for the management of chronic liver diseases. However, the commonly used B-mode ultrasound is qualitative and can cause interobserver or intraobserver difference. Ultrasound backscatter envelope statistics parametric imaging is an important group of quantitative ultrasound techniques that have been applied to characterizing different kinds of tissue. However, a state-of-the-art review of ultrasound backscatter envelope statistics parametric imaging for liver fibrosis characterization has not been conducted. In this paper, we focused on the development of ultrasound backscatter envelope statistics parametric imaging techniques for assessing liver fibrosis from 1998 to September 2019. We classified these techniques into six categories: constant false alarm rate, fiber structure extraction technique, acoustic structure quantification, quantile-quantile probability plot, the multi-Rayleigh model, and the Nakagami model. We presented the theoretical background and algorithms for liver fibrosis assessment by ultrasound backscatter envelope statistics parametric imaging. Then, the specific applications of ultrasound backscatter envelope statistics parametric imaging techniques to liver fibrosis evaluation were reviewed and analyzed. Finally, the pros and cons of each technique were discussed, and the future development was suggested.
Collapse
Affiliation(s)
- Zhuhuang Zhou
- Department of Biomedical Engineering, College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Anna Gao
- Department of Biomedical Engineering, College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Qiyu Zhang
- Department of Biomedical Engineering, College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Weiwei Wu
- College of Biomedical Engineering, Capital Medical University, Beijing, China
| | - Shuicai Wu
- Department of Biomedical Engineering, College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Po-Hsiang Tsui
- Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Medical Imaging Research Center, Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| |
Collapse
|
5
|
Wang D, Sang Y, Zhang X, Hu H, Lu S, Zhang Y, Fu C, Cloutier G, Wan M. Numerical and experimental investigation of impacts of nonlinear scattering encapsulated microbubbles on Nakagami distribution. Med Phys 2019; 46:5467-5477. [PMID: 31536640 DOI: 10.1002/mp.13833] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 08/06/2019] [Accepted: 09/12/2019] [Indexed: 12/25/2022] Open
Abstract
PURPOSE The Nakagami statistical model and Nakagami shape parameter m have been widely used in linear tissue characterization and preliminarily characterized the envelope distributions of nonlinear encapsulated microbubbles (EMBs). However, the Nakagami distribution of nonlinear scattering EMBs lacked a systematical investigation. Thus, this study aimed to investigate the Nakagami distribution of EMBs and illustrate the impact of EMBs' nonlinearity on the Nakagami model. METHOD A group of simulated EMB phantoms and in vitro EMB dilutions with an increasing concentration distribution under various EMB nonlinearities, as regulated by acoustic parameters, were characterized by using the window-modulated compounding Greenwood-Durand estimator. RESULTS Raw envelope histograms of simulated and in vitro EMBs were well matched with the Nakagami distribution with a high correlation coefficient of 0.965 ± 0.021 (P < 0.005). The mean values and gradients of m parameters of simulated and in vitro EMBs were smaller than those of linear scatterers due to the stronger nonlinearity. These m values exhibited a quasi-linear improvement with the increase in second harmonic nonlinear-to-linear component ratio regulated by pulse lengths and excitation frequencies at low- and high-concentration conditions. CONCLUSIONS The Nakagami distribution was suitable for the EMBs characterization but the corresponding m parameter was affected by the EMBs' nonlinearity. These validations provided support and nonlinear impact assessment for the EMBs' characterization using the Nakagami statistical model in the future.
Collapse
Affiliation(s)
- Diya Wang
- University of Montreal Hospital Research Center, Montreal, QC, H2X 0A9, Canada.,Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 71049, P. R. China
| | - Yuchao Sang
- Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 71049, P. R. China
| | - Xinyu Zhang
- Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 71049, P. R. China
| | - Hong Hu
- Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 71049, P. R. China
| | - Shukuan Lu
- Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 71049, P. R. China
| | - Yu Zhang
- Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 71049, P. R. China
| | - Chaoying Fu
- Center Lab of Longhua Branch and Department of Infectious disease, Shenzhen People's Hospital, 2nd Clinical Medical College of Jinan University, Shenzhen, 518120, China.,Institut National de la Recherche Scientifique (INRS) EMT Center, Varennes, QC, J3X 1S2, Canada
| | - Guy Cloutier
- University of Montreal Hospital Research Center, Montreal, QC, H2X 0A9, Canada
| | - Mingxi Wan
- Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 71049, P. R. China
| |
Collapse
|
6
|
Han M, Wang N, Guo S, Chang N, Lu S, Wan M. Nakagami-m parametric imaging for characterization of thermal coagulation and cavitation erosion induced by HIFU. ULTRASONICS SONOCHEMISTRY 2018; 45:78-85. [PMID: 29705328 DOI: 10.1016/j.ultsonch.2018.03.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 03/13/2018] [Accepted: 03/15/2018] [Indexed: 06/08/2023]
Abstract
Nowadays, both thermal and mechanical ablation techniques of HIFU associated with cavitation have been developed for noninvasive treatment. A specific challenge for the successful clinical implementation of HIFU is to achieve real-time imaging for the evaluation and determination of therapy outcomes such as necrosis or homogenization. Ultrasound Nakagami-m parametric imaging highlights the degrading shadowing effects of bubbles and can be used for tissue characterization. The aim of this study is to investigate the performance of Nakagami-m parametric imaging for evaluating and differentiating thermal coagulation and cavitation erosion induced by HIFU. Lesions were induced in basic bovine serum albumin (BSA) phantoms and ex vivo porcine livers using a 1.6 MHz single-element transducer. Thermal and mechanical lesions induced by two types of HIFU sequences respectively were evaluated using Nakagami-m parametric imaging and ultrasound B-mode imaging. The lesion sizes estimated using Nakagami-m parametric imaging technique were all closer to the actual sizes than those of B-mode imaging. The p-value obtained from the t-test between the mean m values of thermal coagulation and cavitation erosion was smaller than 0.05, demonstrating that the m values of thermal lesions were significantly different from that of mechanical lesions, which was confirmed by ex vivo experiments and histologic examination showed that different changes result from HIFU exposure, one of tissue dehydration resulting from the thermal effect, and the other of tissue homogenate resulting from mechanical effect. This study demonstrated that Nakagami-m parametric imaging is a potential real-time imaging technique for evaluating and differentiating thermal coagulation and cavitation erosion.
Collapse
Affiliation(s)
- Meng Han
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Na Wang
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Shifang Guo
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Nan Chang
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Shukuan Lu
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Mingxi Wan
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China.
| |
Collapse
|
7
|
Zhou Z, Wu S, Lin MY, Fang J, Liu HL, Tsui PH. Three-dimensional Visualization of Ultrasound Backscatter Statistics by Window-modulated Compounding Nakagami Imaging. ULTRASONIC IMAGING 2018; 40:171-189. [PMID: 29506441 DOI: 10.1177/0161734618756101] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In this study, the window-modulated compounding (WMC) technique was integrated into three-dimensional (3D) ultrasound Nakagami imaging for improving the spatial visualization of backscatter statistics. A 3D WMC Nakagami image was produced by summing and averaging a number of 3D Nakagami images (number of frames denoted as N) formed using sliding cubes with varying side lengths ranging from 1 to N times the transducer pulse. To evaluate the performance of the proposed 3D WMC Nakagami imaging method, agar phantoms with scatterer concentrations ranging from 2 to 64 scatterers/mm3 were made, and six stages of fatty liver (zero, one, two, four, six, and eight weeks) were induced in rats by methionine-choline-deficient diets (three rats for each stage, total n = 18). A mechanical scanning system with a 5-MHz focused single-element transducer was used for ultrasound radiofrequency data acquisition. The experimental results showed that 3D WMC Nakagami imaging was able to characterize different scatterer concentrations. Backscatter statistics were visualized with various numbers of frames; N = 5 reduced the estimation error of 3D WMC Nakagami imaging in visualizing the backscatter statistics. Compared with conventional 3D Nakagami imaging, 3D WMC Nakagami imaging improved the image smoothness without significant image resolution degradation, and it can thus be used for describing different stages of fatty liver in rats.
Collapse
Affiliation(s)
- Zhuhuang Zhou
- 1 College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
- 2 Faculty of Information Technology, Beijing University of Technology, Beijing, China
| | - Shuicai Wu
- 1 College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China
| | - Man-Yen Lin
- 3 Department of Electrical Engineering, Chang Gung University, Taoyuan, Taiwan
| | - Jui Fang
- 4 PhD Program in Biomedical Engineering, College of Engineering, Chang Gung University, Taoyuan, Taiwan
| | - Hao-Li Liu
- 3 Department of Electrical Engineering, Chang Gung University, Taoyuan, Taiwan
| | - Po-Hsiang Tsui
- 5 Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- 6 Medical Imaging Research Center, Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- 7 Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| |
Collapse
|
8
|
Effect of ultrasound frequency on the Nakagami statistics of human liver tissues. PLoS One 2017; 12:e0181789. [PMID: 28763461 PMCID: PMC5538657 DOI: 10.1371/journal.pone.0181789] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 07/07/2017] [Indexed: 12/11/2022] Open
Abstract
The analysis of the backscattered statistics using the Nakagami parameter is an emerging ultrasound technique for assessing hepatic steatosis and fibrosis. Previous studies indicated that the echo amplitude distribution of a normal liver follows the Rayleigh distribution (the Nakagami parameter m is close to 1). However, using different frequencies may change the backscattered statistics of normal livers. This study explored the frequency dependence of the backscattered statistics in human livers and then discussed the sources of ultrasound scattering in the liver. A total of 30 healthy participants were enrolled to undergo a standard care ultrasound examination on the liver, which is a natural model containing diffuse and coherent scatterers. The liver of each volunteer was scanned from the right intercostal view to obtain image raw data at different central frequencies ranging from 2 to 3.5 MHz. Phantoms with diffuse scatterers only were also made to perform ultrasound scanning using the same protocol for comparisons with clinical data. The Nakagami parameter-frequency correlation was evaluated using Pearson correlation analysis. The median and interquartile range of the Nakagami parameter obtained from livers was 1.00 (0.98-1.05) for 2 MHz, 0.93 (0.89-0.98) for 2.3 MHz, 0.87 (0.84-0.92) for 2.5 MHz, 0.82 (0.77-0.88) for 3.3 MHz, and 0.81 (0.76-0.88) for 3.5 MHz. The Nakagami parameter decreased with the increasing central frequency (r = -0.67, p < 0.0001). However, the effect of ultrasound frequency on the statistical distribution of the backscattered envelopes was not found in the phantom results (r = -0.147, p = 0.0727). The current results demonstrated that the backscattered statistics of normal livers is frequency-dependent. Moreover, the coherent scatterers may be the primary factor to dominate the frequency dependence of the backscattered statistics in a liver.
Collapse
|
9
|
Weng WC, Tsui PH, Lin CW, Lu CH, Lin CY, Shieh JY, Lu FL, Ee TW, Wu KW, Lee WT. Evaluation of muscular changes by ultrasound Nakagami imaging in Duchenne muscular dystrophy. Sci Rep 2017; 7:4429. [PMID: 28667314 PMCID: PMC5493629 DOI: 10.1038/s41598-017-04131-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 05/10/2017] [Indexed: 12/12/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is the most common debilitating muscular disorder. Developing a noninvasive measure for monitoring the progression of this disease is critical. The present study tested the effectiveness of using ultrasound Nakagami imaging to evaluate the severity of the dystrophic process. A total of 47 participants (40 with DMD and 7 healthy controls) were recruited. Patients were classified into stage 1 (presymptomatic and ambulatory), stage 2 (early nonambulatory), and stage 3 (late nonambulatory). All participants underwent ultrasound examinations on the rectus femoris, tibialis anterior, and gastrocnemius. The results revealed that the ultrasound Nakagami parameter correlated positively with functional severity in the patients with DMD. The median Nakagami parameter of the gastrocnemius muscle increased from 0.50 to 0.85, corresponding to the largest dynamic range between normal and stage 3. The accuracy, sensitivity, and specificity of diagnosing walking function were 85.52%, 76.31%, and 94.73%, respectively. The Nakagami parameter of the rectus femoris and gastrocnemius muscles correlated negatively with the 6-minute walking distance in the ambulatory patients. Therefore, changes in the Nakagami parameter for the gastrocnemius muscle are suitable for monitoring disease progression in ambulatory patients and for predicting ambulation loss. Ultrasound Nakagami imaging shows potential for evaluating patients with DMD.
Collapse
Affiliation(s)
- Wen-Chin Weng
- Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan.,Department of Pediatrics, College of Medicine, National Taiwan University, Taipei, Taiwan.,Department of Pediatric Neurology, National Taiwan University Children's Hospital, Taipei, Taiwan
| | - Po-Hsiang Tsui
- Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan.,Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Chia-Wei Lin
- Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital Hsin-Chu Branch, Hsin-Chu, Taiwan
| | - Chun-Hao Lu
- Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chun-Yen Lin
- Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan.,Department of Pediatrics, Yong-He Cardinal Tien Hospital, Taipei, Taiwan
| | - Jeng-Yi Shieh
- Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital, Taipei, Taiwan
| | - Frank Leigh Lu
- Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan.,Department of Pediatrics, College of Medicine, National Taiwan University, Taipei, Taiwan.,Department of Pediatric Neurology, National Taiwan University Children's Hospital, Taipei, Taiwan
| | - Ting-Wei Ee
- Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Kuan-Wen Wu
- Department of Orthopaedic Surgery, National Taiwan University Hospital, Taipei, Taiwan
| | - Wang-Tso Lee
- Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan. .,Department of Pediatrics, College of Medicine, National Taiwan University, Taipei, Taiwan. .,Department of Pediatric Neurology, National Taiwan University Children's Hospital, Taipei, Taiwan. .,Graduate Institute of Brain and Mind Sciences, National Taiwan University, Taipei, Taiwan.
| |
Collapse
|
10
|
Han M, Wan J, Zhao Y, Zhou X, Wan M. Nakagami-m Parametric Imaging for Atherosclerotic Plaque Characterization Using the Coarse-to-Fine Method. ULTRASOUND IN MEDICINE & BIOLOGY 2017; 43:1275-1289. [PMID: 28392001 DOI: 10.1016/j.ultrasmedbio.2017.01.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 11/15/2016] [Accepted: 01/30/2017] [Indexed: 06/07/2023]
Abstract
The Nakagami model was used to analyze the statistical differences in ultrasound backscattered signals between different plaque types. To improve image resolution, Nakagami-m parametric imaging using the coarse-to-fine method based on the maximum likelihood estimation (CTF-BOW) was proposed for atherosclerotic plaque characterization. Simulation results confirmed that the CTF-BOW method significantly outperforms the sliding window method in precision, smoothness and resolution. Preliminary in vivo results (n = 45) indicated that the ranges of the m parameters for calcified, mixed and echolucent plaques are, respectively, 0.2852-0.5225, 0.6532-0.8784 and 0.8908-1.4011, with no overlap. Results revealed that the CTF-BOW method significantly improves image resolution without sacrificing accuracy and can distinguish between calcified, mixed and echolucent plaques. Moreover, it was found that the parameter m is related to the composition of the plaque, indicating that Nakagami-m parametric imaging has the potential to characterize plaques.
Collapse
Affiliation(s)
- Meng Han
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Jinjin Wan
- Science and Technology on Electro-optical Control Laboratory, Luoyang, China
| | - Yongfeng Zhao
- Department of Ultrasound, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Xiaodong Zhou
- Department of Ultrasound, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Mingxi Wan
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China.
| |
Collapse
|
11
|
Small-window parametric imaging based on information entropy for ultrasound tissue characterization. Sci Rep 2017; 7:41004. [PMID: 28106118 PMCID: PMC5247684 DOI: 10.1038/srep41004] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 11/15/2016] [Indexed: 12/26/2022] Open
Abstract
Constructing ultrasound statistical parametric images by using a sliding window is a widely adopted strategy for characterizing tissues. Deficiency in spatial resolution, the appearance of boundary artifacts, and the prerequisite data distribution limit the practicability of statistical parametric imaging. In this study, small-window entropy parametric imaging was proposed to overcome the above problems. Simulations and measurements of phantoms were executed to acquire backscattered radiofrequency (RF) signals, which were processed to explore the feasibility of small-window entropy imaging in detecting scatterer properties. To validate the ability of entropy imaging in tissue characterization, measurements of benign and malignant breast tumors were conducted (n = 63) to compare performances of conventional statistical parametric (based on Nakagami distribution) and entropy imaging by the receiver operating characteristic (ROC) curve analysis. The simulation and phantom results revealed that entropy images constructed using a small sliding window (side length = 1 pulse length) adequately describe changes in scatterer properties. The area under the ROC for using small-window entropy imaging to classify tumors was 0.89, which was higher than 0.79 obtained using statistical parametric imaging. In particular, boundary artifacts were largely suppressed in the proposed imaging technique. Entropy enables using a small window for implementing ultrasound parametric imaging.
Collapse
|
12
|
Tsui PH, Ho MC, Tai DI, Lin YH, Wang CY, Ma HY. Acoustic structure quantification by using ultrasound Nakagami imaging for assessing liver fibrosis. Sci Rep 2016; 6:33075. [PMID: 27605260 PMCID: PMC5015103 DOI: 10.1038/srep33075] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 08/19/2016] [Indexed: 02/07/2023] Open
Abstract
Acoustic structure quantification (ASQ) is a recently developed technique widely used for detecting liver fibrosis. Ultrasound Nakagami parametric imaging based on the Nakagami distribution has been widely used to model echo amplitude distribution for tissue characterization. We explored the feasibility of using ultrasound Nakagami imaging as a model-based ASQ technique for assessing liver fibrosis. Standard ultrasound examinations were performed on 19 healthy volunteers and 91 patients with chronic hepatitis B and C (n = 110). Liver biopsy and ultrasound Nakagami imaging analysis were conducted to compare the METAVIR score and Nakagami parameter. The diagnostic value of ultrasound Nakagami imaging was evaluated using receiver operating characteristic (ROC) curves. The Nakagami parameter obtained through ultrasound Nakagami imaging decreased with an increase in the METAVIR score (p < 0.0001), representing an increase in the extent of pre-Rayleigh statistics for echo amplitude distribution. The area under the ROC curve (AUROC) was 0.88 for the diagnosis of any degree of fibrosis (≥F1), whereas it was 0.84, 0.69, and 0.67 for ≥F2, ≥F3, and ≥F4, respectively. Ultrasound Nakagami imaging is a model-based ASQ technique that can be beneficial for the clinical diagnosis of early liver fibrosis.
Collapse
Affiliation(s)
- Po-Hsiang Tsui
- Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Ming-Chih Ho
- Department of Surgery, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Dar-In Tai
- Department of Gastroenterology and Hepatology, Chang Gung Memorial Hospital at Linkou, Chang Gung University, Taoyuan, Taiwan
| | - Ying-Hsiu Lin
- Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Chiao-Yin Wang
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Hsiang-Yang Ma
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| |
Collapse
|
13
|
Ma HY, Lin YH, Wang CY, Chen CN, Ho MC, Tsui PH. Ultrasound window-modulated compounding Nakagami imaging: Resolution improvement and computational acceleration for liver characterization. ULTRASONICS 2016; 70:18-28. [PMID: 27125557 DOI: 10.1016/j.ultras.2016.04.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 03/16/2016] [Accepted: 04/15/2016] [Indexed: 06/05/2023]
Abstract
Ultrasound Nakagami imaging is an attractive method for visualizing changes in envelope statistics. Window-modulated compounding (WMC) Nakagami imaging was reported to improve image smoothness. The sliding window technique is typically used for constructing ultrasound parametric and Nakagami images. Using a large window overlap ratio may improve the WMC Nakagami image resolution but reduces computational efficiency. Therefore, the objectives of this study include: (i) exploring the effects of the window overlap ratio on the resolution and smoothness of WMC Nakagami images; (ii) proposing a fast algorithm that is based on the convolution operator (FACO) to accelerate WMC Nakagami imaging. Computer simulations and preliminary clinical tests on liver fibrosis samples (n=48) were performed to validate the FACO-based WMC Nakagami imaging. The results demonstrated that the width of the autocorrelation function and the parameter distribution of the WMC Nakagami image reduce with the increase in the window overlap ratio. One-pixel shifting (i.e., sliding the window on the image data in steps of one pixel for parametric imaging) as the maximum overlap ratio significantly improves the WMC Nakagami image quality. Concurrently, the proposed FACO method combined with a computational platform that optimizes the matrix computation can accelerate WMC Nakagami imaging, allowing the detection of liver fibrosis-induced changes in envelope statistics. FACO-accelerated WMC Nakagami imaging is a new-generation Nakagami imaging technique with an improved image quality and fast computation.
Collapse
Affiliation(s)
- Hsiang-Yang Ma
- Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Ying-Hsiu Lin
- Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chiao-Yin Wang
- Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chiung-Nien Chen
- Department of Surgery, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Ming-Chih Ho
- Department of Surgery, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan.
| | - Po-Hsiang Tsui
- Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan; Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan.
| |
Collapse
|