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McFarlin BL, Villegas-Downs M, Mohammadi M, Han A, Simpson DG, O'Brien WD. Enhanced identification of women at risk for preterm birth via quantitative ultrasound: a prospective cohort study. Am J Obstet Gynecol MFM 2024; 6:101250. [PMID: 38070676 PMCID: PMC11032231 DOI: 10.1016/j.ajogmf.2023.101250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 11/28/2023] [Accepted: 12/04/2023] [Indexed: 01/09/2024]
Abstract
BACKGROUND Historically, clinicians have relied on medical risk factors and clinical symptoms for preterm birth risk assessment. In nulliparous women, clinicians may rely solely on reported symptoms to assess for the risk of preterm birth. The routine use of ultrasound during pregnancy offers the opportunity to incorporate quantitative ultrasound scanning of the cervix to potentially improve assessment of preterm birth risk. OBJECTIVE This study aimed to investigate the efficiency of quantitative ultrasound measurements at relatively early stages of pregnancy to enhance identification of women who might be at risk for spontaneous preterm birth. STUDY DESIGN A prospective cohort study of pregnant women was conducted with volunteer participants receiving care from the University of Illinois Hospital in Chicago, Illinois. Participants received a standard clinical screening followed by 2 research screenings conducted at 20±2 and 24±2 weeks. Quantitative ultrasound scans were performed during research screenings by registered diagnostic medical sonographers using a standard cervical length approach. Quantitative ultrasound features were computed from calibrated raw radiofrequency backscattered signals. Full-term birth outcomes and spontaneous preterm birth outcomes were included in the analysis. Medically indicated preterm births were excluded from the analysis. Using data from each visit, logistic regression with Akaike information criterion feature selection was conducted to derive predictive models for each time frame based on historical clinical and quantitative ultrasound features. Model evaluations included a likelihood ratio test of quantitative ultrasound features, cross-validated receiver operating characteristic curve analysis, sensitivity, and specificity. RESULTS On the basis of historical clinical features alone, the best predictive model had an estimated receiver operating characteristic area under the curve of 0.56±0.03. By the time frame of Visit 1, a predictive model using both historical clinical and quantitative ultrasound features provided a modest improvement in the area under the curve (0.63±0.03) relative to that of the predictive model using only historical clinical features. By the time frame of Visit 2, the predictive model using historical clinical and quantitative ultrasound features provided significant improvement (likelihood ratio test, P<.01), with an area under the curve of 0.69±0.03. CONCLUSION Accurate identification of women at risk for spontaneous preterm birth solely through historical clinical features has been proven to be difficult. In this study, a history of preterm birth was the most significant historical clinical predictor of preterm birth risk, but the historical clinical predictive model performance was not statistically significantly better than the no-skill level. According to our study results, including quantitative ultrasound yields a statistically significant improvement in risk prediction as the pregnancy progresses.
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Affiliation(s)
- Barbara L McFarlin
- Department of Human Development Nursing Science, UIC College of Nursing, University of Illinois Chicago, Chicago, IL (Dr McFarlin and Ms Villegas-Downs).
| | - Michelle Villegas-Downs
- Department of Human Development Nursing Science, UIC College of Nursing, University of Illinois Chicago, Chicago, IL (Dr McFarlin and Ms Villegas-Downs)
| | - Mehrdad Mohammadi
- Department of Statistics, University of Illinois Urbana-Champaign, Champaign, IL (Mr Mohammadi and Dr Simpson)
| | - Aiguo Han
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA (Dr Han)
| | - Douglas G Simpson
- Department of Statistics, University of Illinois Urbana-Champaign, Champaign, IL (Mr Mohammadi and Dr Simpson)
| | - William D O'Brien
- Bioacoustics Research Laboratory, Department of Electrical and Computer Engineering, University of Illinois Urbana-Champaign, Urbana, IL (Dr O'Brien)
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Wharton LK, Anumba DOC. Techniques for detecting cervical remodeling as a predictor for spontaneous preterm birth: current evidence and future research avenues in patients with multiple pregnancies. J Matern Fetal Neonatal Med 2023; 36:2262081. [PMID: 37778754 DOI: 10.1080/14767058.2023.2262081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Accepted: 09/18/2023] [Indexed: 10/03/2023]
Abstract
BACKGROUND Spontaneous preterm birth occurs more frequently in multiple pregnancies. This syndrome has multiple triggers that result in a unified downstream pathway of cervical remodeling, uterine activity, and progressive cervical dilatation. Whilst the triggers for labor in multiple pregnancy may be different from singletons, the downstream changes will be the same. Identifying patients at risk of preterm birth is a priority as interventions to delay delivery and optimize the fetus can be initiated. Methods for screening for risk of preterm birth which focus on the detection of cervical remodeling may therefore have potential in this population. METHODS This review explores the evidence for the predictive utility for preterm birth of several published techniques that assess the physical, biomechanical, and optical properties of the cervix, with a focus on those which have been studied in multiple pregnancies and highlighting targets for future research in this population. RESULTS Fifteen techniques are discussed which assess the physical, biomechanical, and optical properties of the cervix in pregnancy. Of these, only three techniques that evaluated the predictive accuracy of a technique in patients with multiple pregnancies were identified: uterocervical angle, cervical consistency index, and cervical elastography. Of these, measurement of the uterocervical angle has the strongest evidence. Several techniques have shown predictive potential in singleton pregnancies, but have not yet been studied in multiple pregnancies, which would be a logical expansion of research. CONCLUSION Research on techniques with predictive utility for PTB in patients with multiple pregnancies is limited but should be a research priority. Overall, the theory supports the investigation of cervical remodeling as a predictor of PTB, and there are numerous techniques in development that may have potential in this field.
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Affiliation(s)
- L K Wharton
- Academic Unit of Reproductive and Developmental Medicine, Faculty of Medicine Dentistry and Health, The University of Sheffield, Sheffield, UK
| | - D O C Anumba
- Academic Unit of Reproductive and Developmental Medicine, Faculty of Medicine Dentistry and Health, The University of Sheffield, Sheffield, UK
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McFarlin BL, Liu Y, Villegas-Downs M, Mohammadi M, Simpson DG, Han A, O'Brien WD. Predicting Spontaneous Pre-term Birth Risk Is Improved When Quantitative Ultrasound Data Are Included With Historical Clinical Data. ULTRASOUND IN MEDICINE & BIOLOGY 2023; 49:1145-1152. [PMID: 36740462 DOI: 10.1016/j.ultrasmedbio.2022.12.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 12/13/2022] [Accepted: 12/26/2022] [Indexed: 05/11/2023]
Abstract
OBJECTIVE Predicting women at risk for spontaneous pre-term birth (sPTB) has been medically challenging because of the lack of signs and symptoms of pre-term birth until interventions are too late. We hypothesized that prediction of the sPTB risk level is enhanced when using both historical clinical (HC) data and quantitative ultrasound (QUS) data compared with using only HC data. HC data defined herein included birth history prior to that of the current pregnancy as well as, from the current pregnancy, a clinical cervical length assessment and physical examination data. METHODS The study population included 248 full-term births (FTBs) and 26 sPTBs. QUS scans (Siemens S2000 and MC9-4) were performed by registered diagnostic medical sonographers using a standard cervical length approach. Two cervical QUS scans were conducted at 20 ± 2 and 24 ± 2 wk of gestation. Multiple QUS features were evaluated from calibrated raw radiofrequency backscattered ultrasonic signals. Two statistical models designed to determine sPTB risk were compared: (i) HC data alone and (ii) combined HC and QUS data. Model comparisons included a likelihood ratio test, cross-validated receiver operating characteristic area under the curve, sensitivity and specificity. The study's birth outcomes were only FTBs and sPTBs; medically induced pre-term births were not included. DISCUSSION Combined HC and QUS data identified women at risk of sPTB with better AUC (0.68, 95% confidence interval [CI]: 0.57-0.78) compared with HC data alone (0.53, 95% CI: 0.40-0.66) and HC data + cervical length at 18-20 wk of gestation (average AUC = 0.51, 95% CI: 0.38-0.64). A likelihood ratio test for significance of QUS features in the classification model was highly statistically significant (p < 0.01). CONCLUSION Even with only 26 sPTBs among 274 births, value was added in predicting sPTB when QUS data were included with HC data.
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Affiliation(s)
- Barbara L McFarlin
- Department of Human Development Nursing Science, UIC College of Nursing, University of Illinois Chicago, Chicago, IL, USA
| | - Yuxuan Liu
- Department of Statistics, University of Illinois Urbana-Champaign, Champaign, IL, USA
| | - Michelle Villegas-Downs
- Department of Human Development Nursing Science, UIC College of Nursing, University of Illinois Chicago, Chicago, IL, USA
| | - Mehrdad Mohammadi
- Department of Statistics, University of Illinois Urbana-Champaign, Champaign, IL, USA
| | - Douglas G Simpson
- Department of Statistics, University of Illinois Urbana-Champaign, Champaign, IL, USA
| | - Aiguo Han
- Bioacoustics Research Laboratory, Department of Electrical and Computer Engineering, University of Illinois Urbana-Champaign, Urbana, IL, USA
| | - William D O'Brien
- Bioacoustics Research Laboratory, Department of Electrical and Computer Engineering, University of Illinois Urbana-Champaign, Urbana, IL, USA.
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Stoian D, Moisa L, Taban L, Sporea I, Popa A, Bende F, Popescu A, Borlea A. Quantification of Thyroid Viscosity in Healthy Subjects Using Ultrasound Shear Wave Dispersion (Viscosity PLUS). Diagnostics (Basel) 2022; 12:diagnostics12092194. [PMID: 36140595 PMCID: PMC9497532 DOI: 10.3390/diagnostics12092194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/04/2022] [Accepted: 09/07/2022] [Indexed: 11/21/2022] Open
Abstract
Shear-wave elastography (SWE) is widely used in thyroid evaluation, but multiple factors influence thyroid stiffness. Estimating tissue viscosity may enhance the ultrasound diagnosis of thyroid diseases, along with the ultrasound (US) and the SWE assessment. In order to be able to detect diffuse thyroid disease by viscosity measurements, it is essential to firstly define the normal values of thyroid viscosity in healthy subjects. Currently there are no published data on thyroid viscosity measurements. This first prospective study aimed to determine the normal range of thyroid viscosity values in a cohort of healthy thyroids, as well as to determine the factors that may influence them. One hundred and twenty-one consecutive subjects without thyroid pathology were evaluated in the study by means of conventional ultrasound, two-dimensional SWE (2D SWE PLUS) and viscosity plane-wave ultrasound (ViPLUS) embedded in the Supersonic MACH® 30 ultrasound system. Five valid tissue viscosity measurements were obtained for each thyroid lobe in every patient and the median values were analyzed and correlated with the biological and demographic parameters of each patient. Our results reveal that ViPLUS is a highly feasible and reproducible technique for thyroid evaluation. Thyroid stiffness, age, gender, BMI and depth of measurements did not influence the thyroid viscosity values. The mean thyroid viscosity by ViPLUS for normal thyroid tissue was of 2.42 ± 0.41 Pa·s. Viscosity assessment by Supersonic ViPLUS is an innovative, non-invasive technique that has proven to be useful for thyroid US evaluation and remains to demonstrate its effectiveness in identifying patients with thyroid disease.
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Affiliation(s)
- Dana Stoian
- Division of Endocrinology, Department of Internal Medicine II, “Victor Babes” University of Medicine and Pharmacy, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
- DrD Ultrasound Center, M. Cristea Nr. 9, 300029 Timisoara, Romania
| | - Luciana Moisa
- DrD Ultrasound Center, M. Cristea Nr. 9, 300029 Timisoara, Romania
| | - Laura Taban
- Division of Endocrinology, Department of Internal Medicine II, “Victor Babes” University of Medicine and Pharmacy, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
- DrD Ultrasound Center, M. Cristea Nr. 9, 300029 Timisoara, Romania
- Correspondence:
| | - Ioan Sporea
- Division of Gastroenterology and Hepatology, Department of Internal Medicine II, Center for Advanced Research in Gastroenterology and Hepatology, “Victor Babes” University of Medicine and Pharmacy, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
| | - Alexandru Popa
- Division of Gastroenterology and Hepatology, Department of Internal Medicine II, Center for Advanced Research in Gastroenterology and Hepatology, “Victor Babes” University of Medicine and Pharmacy, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
| | - Felix Bende
- Division of Gastroenterology and Hepatology, Department of Internal Medicine II, Center for Advanced Research in Gastroenterology and Hepatology, “Victor Babes” University of Medicine and Pharmacy, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
| | - Alina Popescu
- Division of Gastroenterology and Hepatology, Department of Internal Medicine II, Center for Advanced Research in Gastroenterology and Hepatology, “Victor Babes” University of Medicine and Pharmacy, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
| | - Andreea Borlea
- Division of Endocrinology, Department of Internal Medicine II, “Victor Babes” University of Medicine and Pharmacy, E. Murgu Square, Nr. 2, 300041 Timisoara, Romania
- DrD Ultrasound Center, M. Cristea Nr. 9, 300029 Timisoara, Romania
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Birdi J, D'hooge J, Bertrand A. Spatially Variant Ultrasound Attenuation Mapping Using a Regularized Linear Least-Squares Approach. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2022; 69:1596-1609. [PMID: 35263252 DOI: 10.1109/tuffc.2022.3157949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Quantitative ultrasound methods aim to estimate the acoustic properties of the underlying medium, such as the attenuation and backscatter coefficients, and have applications in various areas including tissue characterization. In practice, tissue heterogeneity makes the coefficient estimation challenging. In this work, we propose a computationally efficient algorithm to map spatial variations of the attenuation coefficient. Our proposed approach adopts a fast, linear least-squares strategy to fit the signal model to data from pulse-echo measurements. As opposed to existing approaches, we directly estimate the attenuation map, that is, the local attenuation coefficient at each axial location by solving a joint estimation problem. In particular, we impose a physical model that couples all these local estimates and combine it with a smooth regularization to obtain a smooth map. Compared to the conventional spectral log difference method and the more recent ALGEBRA approach, we demonstrate that the attenuation estimates obtained by our method are more accurate and better correlate with the ground-truth attenuation profiles over a wide range of spatial and contrast resolutions.
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Cervical Assessment for Predicting Preterm Birth-Cervical Length and Beyond. J Clin Med 2021; 10:jcm10040627. [PMID: 33562187 PMCID: PMC7915684 DOI: 10.3390/jcm10040627] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 01/22/2021] [Accepted: 01/24/2021] [Indexed: 02/07/2023] Open
Abstract
Preterm birth is considered one of the main etiologies of neonatal death, as well as short- and long-term disability worldwide. A number of pathophysiological processes take place in the final unifying factor of cervical modifications that leads to preterm birth. In women at high risk for preterm birth, cervical assessment is commonly used for prediction and further risk stratification. This review outlines the rationale for cervical length screening for preterm birth prediction in different clinical settings within existing and evolving new technologies to assess cervical remodeling.
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Lee W, Ostadi Moghaddam A, Shen S, Phillips H, McFarlin BL, Wagoner Johnson AJ, Toussaint KC. An optomechanogram for assessment of the structural and mechanical properties of tissues. Sci Rep 2021; 11:324. [PMID: 33431940 PMCID: PMC7801423 DOI: 10.1038/s41598-020-79602-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 11/24/2020] [Indexed: 11/25/2022] Open
Abstract
The structural and mechanical properties of tissue and the interplay between them play a critical role in tissue function. We introduce the optomechanogram, a combined quantitative and qualitative visualization of spatially co-registered measurements of the microstructural and micromechanical properties of any tissue. Our approach relies on the co-registration of two independent platforms, second-harmonic generation (SHG) microscopy for quantitative assessment of 3D collagen-fiber microstructural organization, and nanoindentation (NI) for local micromechanical properties. We experimentally validate our method by applying to uterine cervix tissue, which exhibits structural and mechanical complexity. We find statistically significant agreement between the micromechanical and microstructural data, and confirm that the distinct tissue regions are distinguishable using either the SHG or NI measurements. Our method could potentially be used for research in pregnancy maintenance, mechanobiological studies of tissues and their constitutive modeling and more generally for the optomechanical metrology of materials.
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Affiliation(s)
- W Lee
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, 80309, USA
| | - A Ostadi Moghaddam
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Champaign, IL, 61820, USA
| | - S Shen
- Center for Health, Aging, and Disability (CHAD), College of Applied Health Science, University of Illinois at Urbana-Champaign, Champaign, IL, 61820, USA
| | - H Phillips
- Department of Veterinary Clinical Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - B L McFarlin
- Department of Women, Children and Family Health Science, University of Illinois College of Nursing, Chicago, IL, 60612, USA
| | - A J Wagoner Johnson
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Champaign, IL, 61820, USA. .,Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Champaign, IL, 61820, USA. .,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
| | - K C Toussaint
- School of Engineering, Brown University, Providence, RI, 02912, USA.
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Callejas A, Melchor J, Faris IH, Rus G. Viscoelastic model characterization of human cervical tissue by torsional waves. J Mech Behav Biomed Mater 2020; 115:104261. [PMID: 33340778 DOI: 10.1016/j.jmbbm.2020.104261] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 10/10/2020] [Accepted: 12/08/2020] [Indexed: 12/19/2022]
Abstract
The understanding of changes in the viscoelastic properties of cervical tissue during the gestation process is a challenging problem. In this work, we explore the importance of considering the multilayer nature (epithelial and connective layers) of human cervical tissue for characterizing the viscoelastic parameters from torsional waves. For this purpose, torsional wave propagations are simulated in three multilayer cervical tissue models (pure elastic, Kelvin-Voigt (KV) and Maxwell) using the finite difference time domain method. High-speed camera measurements have been carried out in tissue-mimicking phantoms in order to obtain the boundary conditions of the numerical simulations. Finally, a parametric modeling study through a probabilistic inverse procedure was performed to rank the most plausible rheological model and to reconstruct the viscoelastic parameters. The procedure consist in comparing the experimental signals obtained in human cervical tissues using the Torsional Wave Elastography (TWE) technique with the synthetic signals from the numerical models. It is shown that the rheological model that best describes the nature of cervical tissue is the Kelvin-Voigt model. Once the most plausible model has been selected, the stiffness and viscosity parameters have been reconstructed of the epithelial and connective layers for the measurements of the 18 pregnant women, along with the thickness of the epithelial layer.
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Affiliation(s)
- A Callejas
- Department of Structural Mechanics, University of Granada, Granada, Spain; Instituto de Investigación Biosanitaria, ibs.GRANADA, 18012 Granada, Spain.
| | - J Melchor
- Department of Structural Mechanics, University of Granada, Granada, Spain; Instituto de Investigación Biosanitaria, ibs.GRANADA, 18012 Granada, Spain; Excellence Research Unit "Modelling Nature" (MNat) University of Granada, Granada, Spain
| | - Inas H Faris
- Department of Structural Mechanics, University of Granada, Granada, Spain; Instituto de Investigación Biosanitaria, ibs.GRANADA, 18012 Granada, Spain
| | - G Rus
- Department of Structural Mechanics, University of Granada, Granada, Spain; Instituto de Investigación Biosanitaria, ibs.GRANADA, 18012 Granada, Spain; Excellence Research Unit "Modelling Nature" (MNat) University of Granada, Granada, Spain
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Rus G, Faris IH, Torres J, Callejas A, Melchor J. Why Are Viscosity and Nonlinearity Bound to Make an Impact in Clinical Elastographic Diagnosis? SENSORS (BASEL, SWITZERLAND) 2020; 20:E2379. [PMID: 32331295 PMCID: PMC7219338 DOI: 10.3390/s20082379] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/17/2020] [Accepted: 04/20/2020] [Indexed: 12/24/2022]
Abstract
The adoption of multiscale approaches by the biomechanical community has caused a major improvement in quality in the mechanical characterization of soft tissues. The recent developments in elastography techniques are enabling in vivo and non-invasive quantification of tissues' mechanical properties. Elastic changes in a tissue are associated with a broad spectrum of pathologies, which stems from the tissue microstructure, histology and biochemistry. This knowledge is combined with research evidence to provide a powerful diagnostic range of highly prevalent pathologies, from birth and labor disorders (prematurity, induction failures, etc.), to solid tumors (e.g., prostate, cervix, breast, melanoma) and liver fibrosis, just to name a few. This review aims to elucidate the potential of viscous and nonlinear elastic parameters as conceivable diagnostic mechanical biomarkers. First, by providing an insight into the classic role of soft tissue microstructure in linear elasticity; secondly, by understanding how viscosity and nonlinearity could enhance the current diagnosis in elastography; and finally, by compounding preliminary investigations of those elastography parameters within different technologies. In conclusion, evidence of the diagnostic capability of elastic parameters beyond linear stiffness is gaining momentum as a result of the technological and imaging developments in the field of biomechanics.
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Affiliation(s)
- Guillermo Rus
- Ultrasonics Group (TEP-959), Department of Structural Mechanics, University of Granada, 18071 Granada, Spain; (G.R.); (I.H.F.); (A.C.)
- Biomechanics Group (TEC-12), Instituto de Investigación Biosanitaria, ibs.GRANADA, 18012 Granada, Spain;
- Excellence Research Unit “ModelingNature” MNat UCE.PP2017.03, University of Granada, 18071 Granada, Spain
| | - Inas H. Faris
- Ultrasonics Group (TEP-959), Department of Structural Mechanics, University of Granada, 18071 Granada, Spain; (G.R.); (I.H.F.); (A.C.)
- Biomechanics Group (TEC-12), Instituto de Investigación Biosanitaria, ibs.GRANADA, 18012 Granada, Spain;
| | - Jorge Torres
- Ultrasonics Group (TEP-959), Department of Structural Mechanics, University of Granada, 18071 Granada, Spain; (G.R.); (I.H.F.); (A.C.)
- Biomechanics Group (TEC-12), Instituto de Investigación Biosanitaria, ibs.GRANADA, 18012 Granada, Spain;
| | - Antonio Callejas
- Ultrasonics Group (TEP-959), Department of Structural Mechanics, University of Granada, 18071 Granada, Spain; (G.R.); (I.H.F.); (A.C.)
- Biomechanics Group (TEC-12), Instituto de Investigación Biosanitaria, ibs.GRANADA, 18012 Granada, Spain;
| | - Juan Melchor
- Biomechanics Group (TEC-12), Instituto de Investigación Biosanitaria, ibs.GRANADA, 18012 Granada, Spain;
- Excellence Research Unit “ModelingNature” MNat UCE.PP2017.03, University of Granada, 18071 Granada, Spain
- Department of Statistics and Operations Research, University of Granada, 18071 Granada, Spain
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Kumar V, Lee PY, Kim BH, Fatemi M, Alizad A. Gap-filling method for suppressing grating lobes in ultrasound imaging: Experimental study with deep-learning approach. IEEE ACCESS : PRACTICAL INNOVATIONS, OPEN SOLUTIONS 2020; 8:76276-76286. [PMID: 32612897 PMCID: PMC7328874 DOI: 10.1109/access.2020.2989337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Sparse arrays reduce the number of active channels that effectively increases the inter-element spacing. Large inter-element spacing results in grating lobe artifacts degrading the ultrasound image quality and reducing the contrast-to-noise ratio. A deep learning-based custom algorithm is proposed to estimate inactive channel data in periodic sparse arrays. The algorithm uses data from multiple active channels to estimate inactive channels. The estimated inactive channel data effectively reduces the inter-element spacing for beamforming, thus suppressing the grating lobes. Estimated inactive element channel data was combined with active element channel data resulting in a pseudo fully sampled array. The channel data was beamformed using a simple delay-and-sum method and compared with the sparse array and fully sampled array. The performance of the algorithm was validated using a wire target in a water tank, multi-purpose tissue-mimicking phantom, and in-vivo carotid data. Grating lobes suppression up to 15.25 dB was observed with an increase in contrast-to-noise (CNR) for the pseudo fully sampled array. Hypoechoic regions showed more improvement in CNR than hyperechoic regions. Root-mean-square error for unwrapped phase between fully sampled array and the pseudo fully sampled array was low, making the estimated data suitable for Doppler and elastography applications. Speckle pattern was also preserved; thus, the estimated data can also be used for quantitative ultrasound applications. The algorithm can improve the quality of sparse array images and has applications in small scale ultrasound devices and 2D arrays.
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Affiliation(s)
- Viksit Kumar
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
| | - Po-Yang Lee
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
- Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan
| | - Bae-Hyung Kim
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
| | - Mostafa Fatemi
- Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan
| | - Azra Alizad
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
- Department of Radiology, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
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Chen S, McFarlin BL, Meagher BT, Peters TA, Simpson DG, O'Brien WD, Han A. A Phantom-Based Assessment of Repeatability and Reproducibility of Transvaginal Quantitative Ultrasound. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2019; 66:1413-1421. [PMID: 31217100 PMCID: PMC6774614 DOI: 10.1109/tuffc.2019.2921925] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
This article evaluated the repeatability and reproducibility (R&R) of quantitative ultrasound (QUS) biomarkers attenuation coefficient (AC) and backscatter coefficient (BSC) in transvaginal QUS reference phantoms for obstetric applications. Five phantoms were scanned by three sonographers according to the scanning protocol. Each sonographer scanned each phantom with four transvaginal transducers of the same model (MC9-4) and three probe cover types (latex cover, nonlatex cover, and no cover). The AC and BSC were estimated by using a reference phantom method. The R&R analysis was performed for the frequency-averaged AC and logBSC (= 10log10BSC) (5.4-5.8 MHz) by using three-factor random effects Analysis of Variance with interaction. The total R&R variabilities for AC and logBSC are small (AC: 0.042-0.065 dB/cm-MHz; logBSC: 0.50-0.68 dB), indicating high measurement precision. These values are small compared to the ranges of AC (0.28-0.99 dB/cm-MHz) and logBSC (-33.16 to -20.35 dB) of the five phantoms. The AC and logBSC biomarkers measured on transvaginal QUS phantoms using the reference phantom method are repeatable, and reproducible between sonographers, transducers, and probe covers.
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Guerrero QW, Feltovich H, Rosado-Mendez IM, Santoso AP, Carlson LC, Zea R, Hall TJ. Quantitative Ultrasound Parameters Based on the Backscattered Echo Power Signal as Biomarkers of Cervical Remodeling: A Longitudinal Study in the Pregnant Rhesus Macaque. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:1466-1474. [PMID: 30979594 PMCID: PMC7382543 DOI: 10.1016/j.ultrasmedbio.2018.12.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 11/30/2018] [Accepted: 12/12/2018] [Indexed: 06/09/2023]
Abstract
Clinical prediction and especially prevention of abnormal birth timing, particularly pre-term, is poor. The cervix plays a key role in birth timing; it first serves as a rigid barrier to protect the developing fetus, then becomes the pathway to delivery of that fetus. Imaging biomarkers to define this remodeling process could provide insights to improve prediction of birth timing and elucidate novel targets for preventive therapies. Quantitative ultrasound (QUS) approaches that appear promising for this purpose include shear wave speed (SWS) estimation to quantify softness, as well as parameters based on backscattered power, such as the mean backscattered power difference (mBSPD) and specific attenuation coefficient (SAC), to quantify the organization of tissue microstructure. Invasive studies in rodents demonstrated that as pregnancy advances, cervical microstructure disorganizes as tissue softness and compliance increase. Our non-invasive studies in pregnant women and rhesus macaques suggested that QUS can detect these microstructural changes in vivo. Our previous study in the same cohort showed a progressive decline in SWS during pregnancy, consistent with increasing tissue softness, and we hypothesized that backscatter parameters would also decrease, consistent with increasing microstructural disorganization. In this study, we analyzed the mBSPD and SAC in the cervices of rhesus macaques (n = 18). We found that both mBSPD and SAC decreased throughout pregnancy (p < 0.001 for both parameters) and that the former appears to be a more reliable biomarker. In summary, biomarkers that can characterize tissue microstructural organization are promising for comprehensive characterization of cervical remodeling in pregnancy.
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Affiliation(s)
- Quinton W Guerrero
- Medical Physics Department, University of Wisconsin, Madison, Wisconsin, USA
| | - Helen Feltovich
- Medical Physics Department, University of Wisconsin, Madison, Wisconsin, USA; Maternal Fetal Medicine Department, Intermountain Healthcare, Provo, Utah, USA
| | | | - Andrew P Santoso
- Medical Physics Department, University of Wisconsin, Madison, Wisconsin, USA
| | - Lindsey C Carlson
- Medical Physics Department, University of Wisconsin, Madison, Wisconsin, USA; Maternal Fetal Medicine Department, Intermountain Healthcare, Provo, Utah, USA
| | - Ryan Zea
- Department of Biostatistics and Medical Informatics, University of Wisconsin, Madison, Wisconsin, USA
| | - Timothy J Hall
- Medical Physics Department, University of Wisconsin, Madison, Wisconsin, USA.
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Nayak R, Kumar V, Webb J, Fatemi M, Alizad A. Non-invasive Small Vessel Imaging of Human Thyroid Using Motion-Corrected Spatiotemporal Clutter Filtering. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:1010-1018. [PMID: 30718145 PMCID: PMC6391182 DOI: 10.1016/j.ultrasmedbio.2018.10.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 09/13/2018] [Accepted: 10/22/2018] [Indexed: 05/08/2023]
Abstract
Reliable assessment of small vessel blood flow in the thyroid, without using any contrast agents, can be challenging because of increased physiological motion resulting from its proximity to the pulsating carotid artery. In this study, we hypothesized that correction of tissue motion prior to singular value decomposition (SVD)-based clutter filtering can improve the coherency of the tissue components and, thus, may allow better clutter suppression and visualization of small vessels in the thyroid. We corroborated this hypothesis by conducting phantom and in vivo studies using a clinical ultrasound scanner implemented with compounded plane wave imaging. The phantom studies were conducted using a homogeneous tissue-mimicking phantom to study the impact of motion on the covariance of the spatiotemporal Doppler data, in the absence of blood activity. The non-invasive in vivo study was conducted on a 74-y-old woman with a thyroid nodule suspicious of malignancy. A rigid body-based motion correction was performed using tissue displacements obtained from 2-D normalized cross-correlation-based speckle tracking. Subsequently, the power Doppler images were computed using SVD-based spatiotemporal clutter filtering. The results from the phantom study revealed that motion can considerably reduce the covariance of the spatiotemporal data and, thus, increase the rank of the tissue components. When the phantom was subjected to a total translation displacement of 6 pixels over the entire ensemble, in each direction (axial and lateral), the covariance dropped by more than 25%. The results obtained from the non-invasive in vivo study indicated that visualization of small vessel blood flow improved with motion correction of the power Doppler ensemble. The contrast-to-noise ratio of the blood signal in motion-corrected power Doppler images was considerably higher (8.17 and 8.32 dB), compared with that obtained using the standard SVD approach at an optimal threshold (0.87 and 4.33 dB) and a lower singular value threshold (1.92 and 3.05 dB). Further, the covariance of the in vivo thyroid spatiotemporal data increased by approximately 10% with motion correction. These preliminary results indicate that motion correction can be used to improve the visualization of small vessel blood flow in the thyroid, without using any contrast agents. The results of this feasibility study were encouraging, and warrant further development and more in vivo validation in moving tissues and organs.
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Affiliation(s)
- Rohit Nayak
- Department of Radiology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, 55902, United States
- Corresponding Author: Azra Alizad ()
| | - Viksit Kumar
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, 55902, United States
| | - Jeremy Webb
- Department of Radiology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, 55902, United States
| | - Mostafa Fatemi
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, 55902, United States
| | - Azra Alizad
- Department of Radiology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, 55902, United States
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14
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Rowles JL, Han A, Miller RJ, Kelly JR, Applegate CC, Wallig MA, O'Brien WD, Erdman JW. Low fat but not soy protein isolate was an effective intervention to reduce nonalcoholic fatty liver disease progression in C57BL/6J mice: monitored by a novel quantitative ultrasound (QUS) method. Nutr Res 2019; 63:95-105. [PMID: 30824402 DOI: 10.1016/j.nutres.2018.12.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 11/15/2018] [Accepted: 12/04/2018] [Indexed: 10/27/2022]
Abstract
Untreated nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) lead to irreversible liver damage. We hypothesized that a low-fat diet (LFD) or a high-fat diet (HFD) with soy protein isolate (SPI) would be an effective intervention to halt or reverse NAFLD progression. To test these hypotheses, we conducted 2 studies. In the first study, we fed an HFD to 7-week-old C57BL/6J mice to induce NAFLD compared to an LFD (control). Hepatic steatosis was monitored by quantitative ultrasound (QUS) scans (in vivo and ex vivo). Animals were euthanized after 0, 2, 4, and 6 weeks of feeding. In the second study, 7-week-old mice were randomized onto an LFD or HFD with SPI intervention after 4 weeks of feeding HFD. Animals from each group were scanned with QUS and euthanized after 4, 9, and 12 weeks of feeding. Animals fed the HFD developed NAFLD (100%) and NASH (80%) characterized by increased liver weight, lipid accumulation, and histological scores for inflammation by 4 weeks in the first study. In the second study, the LFD ameliorated this NAFLD phenotype after 5 weeks of feeding; however, the SPI intervention failed to significantly attenuate NAFLD. QUS parameters were significantly increased with the HFDs (P < .05) and steatosis grade (P < .05) and were positively correlated with hepatic lipid concentrations. In conclusion, dietary modification may be effective at reversing NAFLD and NASH at early stages. Furthermore, QUS may become a valuable tool to track hepatic steatosis. Additional studies are needed to further evaluate the effectiveness of these interventions.
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Affiliation(s)
- Joe L Rowles
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign
| | - Aiguo Han
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign
| | - Rita J Miller
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign
| | - Jamie R Kelly
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign
| | | | - Matthew A Wallig
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign; Department of Pathobiology, University of Illinois at Urbana-Champaign
| | - William D O'Brien
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign; Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign
| | - John W Erdman
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign; Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign.
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15
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Guerrero QW, Feltovich H, Rosado-Mendez IM, Carlson LC, Hallcor TJ. Quantitative Ultrasound Biomarkers Based on Backscattered Acoustic Power: Potential for Quantifying Remodeling of the Human Cervix during Pregnancy. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:429-439. [PMID: 30473174 PMCID: PMC6324963 DOI: 10.1016/j.ultrasmedbio.2018.08.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 08/24/2018] [Accepted: 08/27/2018] [Indexed: 05/21/2023]
Abstract
As pregnancy progresses, the cervix remodels from a rigid structure to one pliable enough to allow delivery of a fetus, a process that involves progressive disorganization of cervical microstructure. Quantitative ultrasound biomarkers that may detect this process include those derived from the backscattered echo signal, namely, acoustic attenuation and backscattered power loss. We recently reported that attenuation and backscattered power loss are affected by tissue anisotropy and heterogeneity in the ex vivo cervix. In this study, we compared attenuation and backscattered power difference in a group of women in early pregnancy (first trimester) with those in a group in late pregnancy (third trimester). We observed a significant decrease in the backscattered power difference in late as compared with early pregnancy, suggesting decreased microstructural organization in late pregnancy, a finding that is consistent with animal models of cervical remodeling. In contrast, we found no difference in attenuation between the time points. These results suggest that the backscattered power difference, but perhaps not attenuation, may be a useful clinical biomarker of cervical remodeling.
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Affiliation(s)
- Quinton W Guerrero
- Medical Physics Department, University of Wisconsin, Madison, Wisconsin, USA
| | - Helen Feltovich
- Medical Physics Department, University of Wisconsin, Madison, Wisconsin, USA; Maternal Fetal Medicine Department, Intermountain Healthcare, Provo, Utah, USA
| | | | - Lindsey C Carlson
- Medical Physics Department, University of Wisconsin, Madison, Wisconsin, USA; Maternal Fetal Medicine Department, Intermountain Healthcare, Provo, Utah, USA
| | - Timothy J Hallcor
- Medical Physics Department, University of Wisconsin, Madison, Wisconsin, USA.
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16
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Han A, Labyed Y, Sy EZ, Boehringer AS, Andre MP, Erdman JW, Loomba R, Sirlin CB, O'Brien WD. Inter-sonographer reproducibility of quantitative ultrasound outcomes and shear wave speed measured in the right lobe of the liver in adults with known or suspected non-alcoholic fatty liver disease. Eur Radiol 2018; 28:4992-5000. [PMID: 29869170 PMCID: PMC7235946 DOI: 10.1007/s00330-018-5541-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 04/27/2018] [Accepted: 05/14/2018] [Indexed: 12/17/2022]
Abstract
OBJECTIVES To assess inter-sonographer reproducibility of ultrasound attenuation coefficient (AC), backscatter coefficient (BSC) and shear wave speed (SWS) in adults with known/suspected non-alcoholic fatty liver disease (NAFLD). METHODS The institutional review board approved this HIPAA-compliant prospective study; informed consent was obtained. Participants with known/suspected NAFLD were recruited and underwent same-day liver examinations with a clinical scanner. Each participant was scanned by two of the six trained sonographers. Each sonographer performed multiple data acquisitions in the right liver lobe using a lateral intercostal approach. A data acquisition was a single operator button press that recorded a B-mode image, radio-frequency data, and the SWS value. AC and BSC were calculated from the radio-frequency data using the reference phantom method. SWS was calculated automatically using product software. Intraclass correlation coefficient (ICC) and within-subject coefficient of variation (wCV) were calculated for applicable metrics. RESULTS Sixty-one participants were recruited. Inter-sonographer ICC was 0.86 (95% confidence interval: 0.77-0.92) for AC and 0.87 (0.78-0.92) for log-transformed BSC (logBSC = 10log10BSC) using one acquisition per sonographer. ICC was 0.88 (0.80-0.93) for both AC and logBSC averaging 5 acquisitions. ICC for SWS was 0.57 (0.29-0.74) using one acquisition per sonographer, and 0.84 (0.66-0.93) using 10 acquisitions. The wCV was ~7% for AC, and 19-43% for SWS, depending on number of acquisitions. CONCLUSIONS Hepatic AC, BSC and SWS measures on a clinical scanner have good inter-sonographer reproducibility in adults with known or suspected NAFLD. Multiple acquisitions are required for SWS but not AC or BSC to achieve good inter-sonographer reproducibility. KEY POINTS • AC, BSC and SWS measurements are reproducible in adults with NAFLD. • Inter-sonographer reproducibility of SWS measurement improves with more acquisitions being averaged. • Multiple acquisitions are required for SWS but not AC or BSC.
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Affiliation(s)
- Aiguo Han
- Bioacoustics Research Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 306 North Wright Street, Urbana, IL, 61801, USA
| | - Yassin Labyed
- Siemens Healthineers USA, 22010 South East 51st Street, Issaquah, WA, 98029, USA
| | - Ethan Z Sy
- Liver Imaging Group, Department of Radiology, University of California at San Diego, 9452 Medical Center Drive, La Jolla, CA, 92037, USA
| | - Andrew S Boehringer
- Liver Imaging Group, Department of Radiology, University of California at San Diego, 9452 Medical Center Drive, La Jolla, CA, 92037, USA
| | - Michael P Andre
- Department of Radiology, University of California at San Diego, 9500 Gilman Drive, San Diego, CA, 92093, USA
- San Diego VA Healthcare System, San Diego, CA, USA
| | - John W Erdman
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, 905 South Goodwin Avenue, Urbana, IL, 61801, USA
| | - Rohit Loomba
- NAFLD Research Center, Division of Gastroenterology, Department of Medicine, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Claude B Sirlin
- Liver Imaging Group, Department of Radiology, University of California at San Diego, 9452 Medical Center Drive, La Jolla, CA, 92037, USA
| | - William D O'Brien
- Bioacoustics Research Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 306 North Wright Street, Urbana, IL, 61801, USA.
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17
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Blitz MJ, Ghorayeb SR, Pachtman SL, Murphy M, Rahman Z, Prasannan L, Sison CP, Vohra N, Rochelson B. Quantitative Ultrasound Analysis of Proximal and Distal Cervical Tissue Echogenicity in Premature Cervical Remodeling. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2018; 37:2873-2879. [PMID: 29663469 DOI: 10.1002/jum.14647] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 03/04/2018] [Accepted: 03/13/2018] [Indexed: 06/08/2023]
Abstract
OBJECTIVES To determine whether a novel, noninvasive quantitative ultrasound (US) technique can detect differences in proximal and distal cervical tissue echogenicity in women with and without a shortened cervical length (CL). METHODS We conducted a retrospective case-control study of singleton pregnancies at 16 to 26 weeks' gestation in which a transvaginal US examination was performed to measure CL from 2013 to 2015. Initial CLs in cases and controls were less than 2.5 cm and 2.5 cm or greater, respectively. For each US image, a region of interest was selected in the proximal and distal cervical stroma, in both the anterior and posterior cervical lips. The Floyd-Steinberg dithering algorithm transformed grayscale pixels in each region of interest into a binary map. A histogram tabulated the number of black and white pixels, allowing determination of the percent echogenicity. The difference in the percent echogenicity was calculated by subtracting the distal cervical echogenicity (average of anterior and posterior lips) from the proximal cervical echogenicity (average of anterior and posterior lips). RESULTS Ultrasound images from 177 women were analyzed. There was a difference in the percent echogenicity (P < .0001) when comparing women with a short cervix (mean ± SD, 9.8 ± 10.1; n = 102) to women with a normal CL (17.2 ± 9.5; n = 75). Differences were attributable to changes in proximal (P < .008) rather than distal cervical echogenicity. Regardless of CL, the proximal cervix was more echogenic than the distal cervix. CONCLUSIONS A quantitative US analysis of cervical tissue can detect differences in echogenicity between the proximal and distal cervix in the second trimester. Proximal cervical echogenicity is lower with CL of less than 2.5 cm compared to a normal CL.
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Affiliation(s)
- Matthew J Blitz
- Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, North Shore University Hospital, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Manhasset, New York, USA
| | - Sleiman R Ghorayeb
- Department of Radiology, North Shore University Hospital, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Manhasset, New York, USA
- Department of Molecular Medicine, North Shore University Hospital, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Manhasset, New York, USA
- School of Engineering and Applied Sciences, Ultrasound Research Laboratory, Hofstra University, Hempstead, New York, USA
- Center for Immunology and Inflammation, Feinstein Institute for Medical Research, Northwell Health, Manhasset, New York, USA
| | - Sarah L Pachtman
- Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, North Shore University Hospital, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Manhasset, New York, USA
| | - Megan Murphy
- School of Engineering and Applied Sciences, Ultrasound Research Laboratory, Hofstra University, Hempstead, New York, USA
| | - Zara Rahman
- School of Engineering and Applied Sciences, Ultrasound Research Laboratory, Hofstra University, Hempstead, New York, USA
| | - Lakha Prasannan
- Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, North Shore University Hospital, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Manhasset, New York, USA
| | - Cristina P Sison
- Department of Radiology, North Shore University Hospital, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Manhasset, New York, USA
- Department of Molecular Medicine, North Shore University Hospital, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Manhasset, New York, USA
- Biostatistics Unit, Feinstein Institute for Medical Research, Northwell Health, Manhasset, New York, USA
| | - Nidhi Vohra
- Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, North Shore University Hospital, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Manhasset, New York, USA
| | - Burton Rochelson
- Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, North Shore University Hospital, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Manhasset, New York, USA
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18
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Han A, Andre MP, Deiranieh L, Housman E, Erdman JW, Loomba R, Sirlin CB, O’Brien WD. Repeatability and Reproducibility of the Ultrasonic Attenuation Coefficient and Backscatter Coefficient Measured in the Right Lobe of the Liver in Adults With Known or Suspected Nonalcoholic Fatty Liver Disease. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2018; 37:1913-1927. [PMID: 29359454 PMCID: PMC6056350 DOI: 10.1002/jum.14537] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 08/23/2017] [Accepted: 10/22/2017] [Indexed: 05/11/2023]
Abstract
OBJECTIVES To assess the repeatability and reproducibility of the ultrasonic attenuation coefficient (AC) and backscatter coefficient (BSC) measured in the livers of adults with known or suspected nonalcoholic fatty liver disease (NAFLD). METHODS The Institutional Review Board approved this Health Insurance Portability and Accountability Act-compliant prospective study; informed consent was obtained. Forty-one research participants with known or suspected NAFLD were recruited and underwent same-day ultrasound examinations of the right liver lobe with a clinical scanner by a clinical sonographer. Each participant underwent 2 scanning trials, with participant repositioning between trials. Two transducers were used in each trial. For each transducer, machine settings were optimized by the sonographer but then kept constant while 3 data acquisitions were obtained from the liver without participant repositioning and then from an external calibrated phantom. Raw RF echo data were recorded. The AC and BSC were measured within 2.6 to 3.0 MHz from a user-defined hepatic field of interest from each acquisition. The repeatability and reproducibility were analyzed by random-effects models. RESULTS The mean AC and log-transformed BSC (logBSC) were 0.94 dB/cm-MHz and -27.0 dB, respectively. Intraclass correlation coefficients were 0.88 to 0.94 for the AC and 0.87 to 0.95 for the logBSC acquired without participant repositioning. For between-trial repeated scans with participant repositioning, the intraclass correlation coefficients were 0.80 to 0.84 for the AC and 0.69 to 0.82 for the logBSC after averaging results from 3 within-trial images. The variability introduced by the transducer was less than the repeatability error. CONCLUSIONS Hepatic AC and BSC measures using a reference phantom technique on a clinical scanner are repeatable and reproducible between transducers in adults with known or suspected NAFLD.
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Affiliation(s)
- Aiguo Han
- Bioacoustics Research Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 405 North Mathews Avenue, Urbana, IL 61801
| | - Michael P. Andre
- Department of Radiology, University of California, San Diego, 9500 Gilman Dr., San Diego, CA 92093, and the San Diego VA Healthcare System, San Diego
| | - Lisa Deiranieh
- Department of Radiology, University of California, San Diego, 9500 Gilman Dr., San Diego, CA 92093, and the San Diego VA Healthcare System, San Diego
| | - Elise Housman
- Department of Radiology, University of California, San Diego, 9500 Gilman Dr., San Diego, CA 92093, and the San Diego VA Healthcare System, San Diego
| | - John W. Erdman
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, 905 South Goodwin Avenue, Urbana, IL 61801
| | - Rohit Loomba
- NAFLD Research Center, Division of Gastroenterology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093
| | - Claude B. Sirlin
- Liver Imaging Group, Department of Radiology, University of California, San Diego, 9452 Medical Center Drive, La Jolla, CA 92037
| | - William D. O’Brien
- Bioacoustics Research Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 405 North Mathews Avenue, Urbana, IL 61801
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19
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Han A. A Method for Stereological Determination of the Structure Function From Histological Sections of Isotropic Scattering Media. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2018; 65:1007-1016. [PMID: 29856718 PMCID: PMC5997396 DOI: 10.1109/tuffc.2018.2818071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The frequency-dependent ultrasonic backscatter coefficient (BSC) from tissues, a fundamental parameter estimated by quantitative ultrasound (QUS) techniques, contains microstructure information useful for tissue characterization. To extract the microstructure information from the BSC, the tissue under investigation is often modeled as a collection of discrete scatterers embedded in a homogeneous background. From a discrete scatterer point of view, the BSC is dependent on not only the properties of individual scatterers relative to the background but also the scatterer spatial arrangement [described by the structure function (SF)]. Recently, the 2-D SF was computed from histological tissue sections, and was shown to be related to the volumetric SF extracted from QUS measurements. In this paper, a stereological method is proposed to extract the volumetric (3-D) SF from 2-D histological tissue sections. Simulations and experimental cell pellet biophantom studies were conducted to evaluate the proposed method. Simulation results verified the proposed method. Experimental results showed that the volumetric SF extracted using the proposed method had a significantly better agreement with the QUS-extracted SF than did the 2-D SF extracted in the previous study. The proposed stereological approach provides a useful tool for predicting the SF from histology.
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20
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Baños N, Perez-Moreno A, Julià C, Murillo-Bravo C, Coronado D, Gratacós E, Deprest J, Palacio M. Quantitative analysis of cervical texture by ultrasound in mid-pregnancy and association with spontaneous preterm birth. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2018; 51:637-643. [PMID: 28508418 DOI: 10.1002/uog.17525] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 04/14/2017] [Accepted: 05/05/2017] [Indexed: 06/07/2023]
Abstract
OBJECTIVE New tools are required to improve the identification of women who are at increased risk for spontaneous preterm birth (sPTB). Quantitative analysis of tissue texture on ultrasound has been used to extract robust features from the ultrasound image to detect subtle changes in its microstructure. This may be applied to the cervix. The aim of this study was to determine if there is an association between quantitative analysis of cervical texture (CTx) on mid-trimester ultrasound and sPTB < 37 + 0 weeks' gestation. METHODS This was a single-center nested case-control study of a prospective cohort of 677 consecutive women with singleton pregnancy assessed between 19 + 0 and 24 + 6 weeks' gestation. Women at increased risk for sPTB were included unless they received treatment to prevent sPTB. Women who delivered < 37 + 0 weeks (sPTB) were considered as cases and were matched in a 1: 10 ratio with randomly selected contemporary controls who delivered at term. For each woman, one ultrasound image of the cervix was obtained for which quality was assessed, cervical length (CL) measured offline and a region of interest in the midportion of the anterior cervical lip delineated for use in local binary patterns analysis of CTx. A learning algorithm was developed to obtain the combination of CTx features best associated with sPTB based on feature transformation and discriminant analysis regression. The ability of the learning algorithm to predict sPTB was evaluated using a leave-one-out cross-validation technique, which produced a CTx-based score for each participant. Receiver-operating characteristics (ROC) curves were produced and sensitivity, specificity, and positive and negative likelihood ratios were calculated for the optimal cut-off based on the ROC curve. The results were compared with those obtained for CL. Investigators studying the images were blinded to pregnancy outcome at all times. RESULTS Images from 310 women (27 cases and 283 controls) were of sufficient quality and included in the study. Median CTx-based score was significantly lower in cases compared with controls (-1.01 vs -0.07, P ≤ 0.0001). CTx-based score maintained its significant association with sPTB after adjusting for possible confounders (history of sPTB, conization or Müllerian malformation, and CL < 25 mm). CTx-based score was a better predictor of sPTB (AUC, 0.77; 95% CI, 0.66-0.87) than was CL (AUC, 0.60; 95% CI, 0.47-0.72) (P = 0.03). Median CL was similar for cases and controls (37.7 vs 38.6 mm, P = 0.26), although cases were more likely to have CL < 25 mm (18.5% vs 0.4%, P < 0.001). CONCLUSION Quantitative analysis of CTx enables the extraction of information relevant to sPTB from ultrasound images to generate a CTx-based score that is associated independently with sPTB. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.
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Affiliation(s)
- N Baños
- Fetal i+D Fetal Medicine Research Center, BCNatal - Barcelona Center for Maternal-Fetal and Neonatal Medicine, Hospital Clínic and Hospital Sant Joan de Deu, Institut Clínic de Ginecologia, Obstetricia i Neonatologia, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Universitat de Barcelona, and Center for Biomedical Research on Rare Diseases (CIBER-ER), Barcelona, Spain
| | | | - C Julià
- Fetal i+D Fetal Medicine Research Center, BCNatal - Barcelona Center for Maternal-Fetal and Neonatal Medicine, Hospital Clínic and Hospital Sant Joan de Deu, Institut Clínic de Ginecologia, Obstetricia i Neonatologia, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Universitat de Barcelona, and Center for Biomedical Research on Rare Diseases (CIBER-ER), Barcelona, Spain
| | - C Murillo-Bravo
- Fetal i+D Fetal Medicine Research Center, BCNatal - Barcelona Center for Maternal-Fetal and Neonatal Medicine, Hospital Clínic and Hospital Sant Joan de Deu, Institut Clínic de Ginecologia, Obstetricia i Neonatologia, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Universitat de Barcelona, and Center for Biomedical Research on Rare Diseases (CIBER-ER), Barcelona, Spain
| | - D Coronado
- Transmural Biotech S. L., Barcelona, Spain
| | - E Gratacós
- Fetal i+D Fetal Medicine Research Center, BCNatal - Barcelona Center for Maternal-Fetal and Neonatal Medicine, Hospital Clínic and Hospital Sant Joan de Deu, Institut Clínic de Ginecologia, Obstetricia i Neonatologia, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Universitat de Barcelona, and Center for Biomedical Research on Rare Diseases (CIBER-ER), Barcelona, Spain
| | - J Deprest
- Clinical Department Obstetrics and Gynecology, University Hospitals KU Leuven and Academic Department Development and Regeneration, Biomedical Sciences, KU Leuven, Leuven, Belgium
| | - M Palacio
- Fetal i+D Fetal Medicine Research Center, BCNatal - Barcelona Center for Maternal-Fetal and Neonatal Medicine, Hospital Clínic and Hospital Sant Joan de Deu, Institut Clínic de Ginecologia, Obstetricia i Neonatologia, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Universitat de Barcelona, and Center for Biomedical Research on Rare Diseases (CIBER-ER), Barcelona, Spain
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21
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Abstract
The process of parturition is poorly understood, but the cervix clearly plays a key role. Because of this, recent research efforts have been directed at objective quantification of cervical remodeling. Investigation has focused on two basic areas: (1) quantification of tissue deformability and (2) presence, orientation, and/or concentration of microstructural components (e.g. collagen). Methods to quantify tissue deformability include strain elastography and shear wave elasticity imaging (SWEI). Methods to describe tissue microstructure include attenuation and backscatter. A single parameter is unlikely to describe the complexities of cervical remodeling, but combining related parameters should improve accuracy of cervical evaluation. This chapter reviews options for cervical tissue characterization.
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Affiliation(s)
- Helen Feltovich
- Maternal Fetal Medicine, Intermountain Healthcare, Utah Valley Hospital, 1034 N 500 W, Provo, UT 84604.
| | - Lindsey Drehfal
- Medical Physics, University of Wisconsin-Madison, Madison WI
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Koenig MD, McFarlin BL, Steffen AD, Tussing-Humphreys L, Giurgescu C, Engeland CG, Kominiarek MA, Ciezczak-Karpiel C, O'Brien WD, White-Traut R. Decreased Nutrient Intake Is Associated With Premature Cervical Remodeling. J Obstet Gynecol Neonatal Nurs 2017; 46:123-134. [PMID: 27836660 PMCID: PMC6459010 DOI: 10.1016/j.jogn.2016.08.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2016] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE To examine the direct relationship between nutrient intake and cervical remodeling. DESIGN Longitudinal descriptive design. SETTING Maternal-fetal medicine clinic in a Midwestern urban city. PARTICIPANTS Forty-seven pregnant African American women. METHODS Participants completed the Block brief food frequency questionnaire at 19 to 24 weeks and 27 to 29 weeks gestation and had quantitative ultrasonic attenuation estimates at 19 to 21 weeks, 23 to 25 weeks, 27 to 29 weeks, 31 to 33 weeks, and 35 to 37 weeks gestation. RESULTS Trajectory mixture models identified two subpopulations within our sample: those at risk (n = 36) and at less risk (n = 11) for premature cervical remodeling. More participants in the less-risk group consumed the dietary reference intake for calcium, vitamin A, folate, vitamin E, zinc, and vitamin D than in the at-risk group. The percentage of participants in the less-risk group who consumed the recommended dietary reference intake for vitamin E was twice the percentage of women in the at-risk group (82% and 44%, respectively; p = .004). Mean intake of calcium was almost 1.3 times more (p = .05) and for zinc was 1.5 times more (p = .04) in the less-risk group than in the at-risk group. CONCLUSION Practitioners can inform women that certain nutrients, particularly zinc, calcium, and vitamin E, could be important to the health of the cervix and inhibit premature cervical remodeling, which in turn may help prevent preterm birth.
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23
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Klimonda Z, Postema M, Nowicki A, Litniewski J. Tissue Attenuation Estimation by Mean Frequency Downshift and Bandwidth Limitation. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2016; 63:1107-1115. [PMID: 27254862 DOI: 10.1109/tuffc.2016.2574399] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Attenuation of ultrasound in tissue can be estimated from the propagating pulse center frequency downshift. This method assumes that the envelope of the emitted pulse can be approximated by a Gaussian function and that the attenuation linearly depends on frequency. The resulting downshift of the mean frequency depends not only on attenuation but also on pulse bandwidth and propagation distance. This kind of approach is valid for narrowband pulses and shallow penetration depth. However, for short pulses and deep penetration, the frequency downshift is rather large and the received spectra are modified by the limited bandwidth of the receiving system. In this paper, the modified formula modeling the mean frequency of backscattered echoes is presented. The equation takes into account the limitation of the bandwidth due to bandpass filtration of the received echoes. This approach was applied to simulate the variation of the mean frequency of the pulse propagating for both weakly and strongly attenuating media and for narrowband and wideband pulses. The behavior of both the standard and modified estimates of attenuation has been validated using RF data from a tissue-mimicking phantom. The ultrasound attenuation of the phantom, determined with a corrected equation, was close to its true value, while the result obtained using the original formula was lower by as much as 50% at a depth of 8 cm.
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