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Guerrero QW, Fan L, Brunke S, Milkowski A, Rosado-Mendez IM, Hall TJ. Power Spectrum Consistency among Systems and Transducers. ULTRASOUND IN MEDICINE & BIOLOGY 2018; 44:2358-2370. [PMID: 30093341 PMCID: PMC6511990 DOI: 10.1016/j.ultrasmedbio.2018.05.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/10/2018] [Accepted: 05/11/2018] [Indexed: 05/13/2023]
Abstract
Use of the reference phantom method for computing acoustic attenuation and backscatter is widespread. However, clinical application of these methods has been limited by the need to acquire reference phantom data. We determined that the data acquired from 11 transducers of the same model and five clinical ultrasound systems of the same model produce equivalent estimates of reference phantom power spectra. We describe that the contribution to power spectral density variance among systems and transducers equals that from speckle variance with 59 uncorrelated echo signals. Thus, when the number of uncorrelated lines of data is small, speckle variance will dominate the power spectral density estimate variance introduced by different systems and transducers. These results suggest that, at least for this particular transducer and imaging system combination, one set of reference phantom calibration data is highly representative of the average among equivalent transducers and systems that are in good working order.
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Affiliation(s)
- Quinton W Guerrero
- Medical Physics Department, University of Wisconsin, Madison, Wisconsin, USA
| | - Liexiang Fan
- Siemens Ultrasound Division, Issaquah, Washington, USA
| | - Shelby Brunke
- Siemens Ultrasound Division, Issaquah, Washington, USA
| | | | - Ivan M Rosado-Mendez
- Medical Physics Department, University of Wisconsin, Madison, Wisconsin, USA; Instituto de Física, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Timothy J Hall
- Medical Physics Department, University of Wisconsin, Madison, Wisconsin, USA.
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Ho JE, Rahban Y, Sandhu H, Hiremath PG, Ayalon N, Qin F, Perez AJ, Downing J, Gopal DM, Cheng S, Colucci WS. Preclinical Alterations in Myocardial Microstructure in People with Metabolic Syndrome. Obesity (Silver Spring) 2017; 25:1516-1522. [PMID: 28737258 PMCID: PMC5578717 DOI: 10.1002/oby.21936] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 06/05/2017] [Accepted: 06/13/2017] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Metabolic syndrome (MetS) can lead to myocardial fibrosis, diastolic dysfunction, and eventual heart failure. This study evaluated alterations in myocardial microstructure in people with MetS by using a novel algorithm to characterize ultrasonic signal intensity variation. METHODS Among 254 participants without existing cardiovascular disease (mean age 42 ± 11 years, 75% women), there were 162 with MetS, 47 with obesity without MetS, and 45 nonobese controls. Standard echocardiography was performed, and a novel validated computational algorithm was used to investigate myocardial microstructure based on sonographic signal intensity and distribution. The signal intensity coefficient (SIC [left ventricular microstructure]) was examined. RESULTS The SIC was significantly higher in people with MetS compared with people with (P < 0.001) and without obesity (P = 0.04), even after adjustment for age, sex, body mass index, hypertension, diabetes mellitus, and the ratio of triglyceride (TG) to high-density lipoprotein (HDL) cholesterol (P < 0.05 for all). Clinical correlates of SIC included TG concentrations (r = 0.21, P = 0.0007) and the TG/HDL ratio (r = 0.2, P = 0.001). CONCLUSIONS This study's findings suggest that preclinical MetS and dyslipidemia in particular are associated with altered myocardial signal intensity variation. Future studies are needed to determine whether the SIC may help detect subclinical diseases in people with metabolic disease, with the ultimate goal of targeting preventive efforts.
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Affiliation(s)
- Jennifer E. Ho
- Cardiovascular Research Center and Cardiology Division, Department of Medicine, Massachusetts General Hospital, Boston, MA
| | | | - Harpaul Sandhu
- Temple Heart and Vascular Institute, Temple University, Philadelphia, PA
| | | | - Nir Ayalon
- Cardiovascular Medicine Section, Department of Medicine, Boston University, Boston, MA
| | | | - Alejandro J. Perez
- Cardiovascular Medicine Section, Department of Medicine, Boston University, Boston, MA
| | - Jill Downing
- Cardiovascular Medicine Section, Department of Medicine, Boston University, Boston, MA
| | - Deepa M. Gopal
- Cardiovascular Medicine Section, Department of Medicine, Boston University, Boston, MA
| | - Susan Cheng
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Wilson S. Colucci
- Cardiovascular Medicine Section, Department of Medicine, Boston University, Boston, MA
- Whitaker Cardiovascular Institute, Boston University, Boston, MA
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Oelze ML, Mamou J. Review of Quantitative Ultrasound: Envelope Statistics and Backscatter Coefficient Imaging and Contributions to Diagnostic Ultrasound. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2016; 63:336-51. [PMID: 26761606 PMCID: PMC5551399 DOI: 10.1109/tuffc.2015.2513958] [Citation(s) in RCA: 188] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Conventional medical imaging technologies, including ultrasound, have continued to improve over the years. For example, in oncology, medical imaging is characterized by high sensitivity, i.e., the ability to detect anomalous tissue features, but the ability to classify these tissue features from images often lacks specificity. As a result, a large number of biopsies of tissues with suspicious image findings are performed each year with a vast majority of these biopsies resulting in a negative finding. To improve specificity of cancer imaging, quantitative imaging techniques can play an important role. Conventional ultrasound B-mode imaging is mainly qualitative in nature. However, quantitative ultrasound (QUS) imaging can provide specific numbers related to tissue features that can increase the specificity of image findings leading to improvements in diagnostic ultrasound. QUS imaging can encompass a wide variety of techniques including spectral-based parameterization, elastography, shear wave imaging, flow estimation, and envelope statistics. Currently, spectral-based parameterization and envelope statistics are not available on most conventional clinical ultrasound machines. However, in recent years, QUS techniques involving spectral-based parameterization and envelope statistics have demonstrated success in many applications, providing additional diagnostic capabilities. Spectral-based techniques include the estimation of the backscatter coefficient (BSC), estimation of attenuation, and estimation of scatterer properties such as the correlation length associated with an effective scatterer diameter (ESD) and the effective acoustic concentration (EAC) of scatterers. Envelope statistics include the estimation of the number density of scatterers and quantification of coherent to incoherent signals produced from the tissue. Challenges for clinical application include correctly accounting for attenuation effects and transmission losses and implementation of QUS on clinical devices. Successful clinical and preclinical applications demonstrating the ability of QUS to improve medical diagnostics include characterization of the myocardium during the cardiac cycle, cancer detection, classification of solid tumors and lymph nodes, detection and quantification of fatty liver disease, and monitoring and assessment of therapy.
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Singh GK, Vitola BE, Holland MR, Sekarski T, Patterson BW, Magkos F, Klein S. Alterations in ventricular structure and function in obese adolescents with nonalcoholic fatty liver disease. J Pediatr 2013; 162:1160-8, 1168.e1. [PMID: 23260104 PMCID: PMC3615145 DOI: 10.1016/j.jpeds.2012.11.024] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 10/30/2012] [Accepted: 11/12/2012] [Indexed: 02/06/2023]
Abstract
OBJECTIVE To determine the association among nonalcoholic fatty liver disease (NAFLD), metabolic function, and cardiac function in obese adolescents. STUDY DESIGN Intrahepatic triglyceride (IHTG) content (magnetic resonance spectroscopy), insulin sensitivity and β-cell function (5-hour oral glucose tolerance test with mathematical modeling), and left ventricular function (speckle tracking echocardiography) were determined in 3 groups of age, sex, and Tanner matched adolescents: (1) lean (n=14, body mass index [BMI]=20±2 kg/m2); (2) obese with normal (2.5%) IHTG content (n=15, BMI=35±3 kg/m2); and (3) obese with increased (8.7%) IHTG content (n=15, BMI=37±6 kg/m2). RESULTS The disposition index (β-cell function) and insulin sensitivity index were ∼45% and ∼70% lower, respectively, and whole body insulin resistance, calculated by homeostasis model of assessment-insulin resistance (HOMA-IR), was ∼60% greater, in obese than in lean subjects, and ∼30% and ∼50% lower and ∼150% greater, respectively, in obese subjects with NAFLD than those without NAFLD (P<.05 for all). Left ventricular global longitudinal systolic strain and early diastolic strain rates were significantly decreased in obese than in lean subjects, and in obese subjects with NAFLD than those without NAFLD (P<.05 for all), and were independently associated with HOMA-IR (β=0.634). IHTG content was the only significant independent determinant of insulin sensitivity index (β=-0.770), disposition index (β=-0.651), and HOMA-IR (β=0.738). CONCLUSIONS These findings demonstrate that the presence of NAFLD in otherwise asymptomatic obese adolescents is an early marker of cardiac dysfunction.
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Affiliation(s)
- Gautam K. Singh
- Center for Human Nutrition and Atkins Center of Excellence in Obesity Medicine, Washington University School of Medicine, St. Louis, MO,Department of Pediatrics, Washington University School of Medicine, St. Louis, MO
| | - Bernadette E. Vitola
- Center for Human Nutrition and Atkins Center of Excellence in Obesity Medicine, Washington University School of Medicine, St. Louis, MO,Department of Pediatrics, Washington University School of Medicine, St. Louis, MO
| | - Mark R. Holland
- Center for Human Nutrition and Atkins Center of Excellence in Obesity Medicine, Washington University School of Medicine, St. Louis, MO,Department of Physics, Washington University School of Medicine, St. Louis, MO
| | - Timothy Sekarski
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO
| | - Bruce W. Patterson
- Center for Human Nutrition and Atkins Center of Excellence in Obesity Medicine, Washington University School of Medicine, St. Louis, MO
| | - Faidon Magkos
- Center for Human Nutrition and Atkins Center of Excellence in Obesity Medicine, Washington University School of Medicine, St. Louis, MO
| | - Samuel Klein
- Center for Human Nutrition and Atkins Center of Excellence in Obesity Medicine, Washington University School of Medicine, St. Louis, MO
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Milne ML, Singh GK, Miller JG, Holland MR. Echocardiographic-based assessment of myocardial fiber structure in individual, excised hearts. ULTRASONIC IMAGING 2012; 34:129-141. [PMID: 22972911 DOI: 10.1177/0161734612455580] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The objective of this study was to assess the feasibility of using echocardiographic imaging as an approach for determining the myocardial fiber structure of intact, individual hearts. Seven formalin-fixed, ex vivo sheep hearts were imaged using a commercially available echocardiographic imaging system, and the intrinsic fiber structure for the reconstructed short-axis cross section was determined for a specific distance from the apex of each heart. Diffusion tensor magnetic resonance (DT-MR) images of each heart were acquired and fiber maps were created for comparison with the fiber structure obtained from the corresponding reconstructed echocardiographic images. These two methods of obtaining the fiber structure showed relatively good agreement, suggesting that measurements of fiber orientation for individual hearts can be derived from echocardiographic images. Further development of this method may provide a clinically useful approach for mapping the fiber orientation in individual patients over the heart cycle.
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Affiliation(s)
- Michelle L Milne
- Department of Physics, Washington University, St. Louis, MO, USA
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Anderson CC, Gibson AA, Schaffer JE, Peterson LR, Holland MR, Miller JG. Bayesian parameter estimation for characterizing the cyclic variation of echocardiographic backscatter to assess the hearts of asymptomatic type 2 diabetes mellitus subjects. ULTRASOUND IN MEDICINE & BIOLOGY 2011; 37:805-12. [PMID: 21439721 PMCID: PMC3078972 DOI: 10.1016/j.ultrasmedbio.2011.02.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Revised: 02/01/2011] [Accepted: 02/01/2011] [Indexed: 05/05/2023]
Abstract
Previous studies have shown that effective quantification of the cyclic variation of myocardial ultrasonic backscatter over the heart cycle might provide a non-invasive technique for identifying the early onset of cardiac abnormalities. These studies have demonstrated the potential for measurements of the magnitude and time delay of cyclic variation for identifying early onset of disease. The goal of this study was to extend this approach by extracting additional parameters characterizing the cyclic variation in an effort to better assess subtle changes in myocardial properties in asymptomatic subjects with type 2 diabetes. Echocardiographic images were obtained on a total of 43 age-matched normal control subjects and 100 type 2 diabetics. Cyclic variation data were generated by measuring the average level of ultrasonic backscatter over the heart cycle within a region of interest placed in the posterior wall of the left ventricle. Cyclic variation waveforms were modeled as piecewise linear functions, and quantified using a novel Bayesian parameter estimation method. Magnitude, rise time and slew rate parameters were extracted from models of the data. The ability of each of these parameters to distinguish between normal and type 2 diabetic subjects, and between subjects grouped by glycated hemoglobin (HbA1c) was compared. Results suggest a significant improvement in using measurements of the rise time and slew rate parameters of cyclic variation to differentiate (P < 0.001) the hearts of patients segregated based on widely employed indices of diabetic control compared to differentiation based on the magnitude of cyclic variation.
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Affiliation(s)
- Christian C Anderson
- Laboratory for Ultrasonics, Department of Physics, Washington University, St. Louis, MO, USA
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Holland MR, Gibson AA, Bauer AQ, Peterson LR, Schaffer JE, Bach RG, Cresci S, Miller JG. Echocardiographic tissue characterization demonstrates differences in the left and right sides of the ventricular septum. ULTRASOUND IN MEDICINE & BIOLOGY 2010; 36:1653-1661. [PMID: 20800946 PMCID: PMC2942980 DOI: 10.1016/j.ultrasmedbio.2010.07.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Revised: 06/30/2010] [Accepted: 07/06/2010] [Indexed: 05/29/2023]
Abstract
The left and right ventricular function of the heart are influenced by the complex structure of the ventricular septum. The cyclic variation of ultrasonic backscatter over the cardiac cycle is known to be sensitive to both structural and functional characteristics of the myocardium. The objective of this study was to investigate differences in the measured magnitude and normalized delay of cyclic variation between the left and right sides of the ventricular septum in normal adult subjects (N = 31). The measured mean magnitudes of cyclic variation were found to be 4.9 ± 0.4 dB and 2.4 ± 0.3 dB (mean ± SE; p < 0.0001) and the corresponding normalized delay values were found to be 0.94 ± 0.05 and 1.59 ± 0.12 (mean ± SE; p < 0.0001) for the left and right sides, respectively. These results show significant differences in the measured magnitude and normalized delay of cyclic variation between the left and right sides of the ventricular septum in normal subjects that appear consistent with predictions based on previously described models of cyclic variation of backscatter and reported measurements of transmural differences in strain properties of the septum.
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