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Jesrani AK, Faiq SM, Rashid R, Kalwar TA, Mohsin R, Aziz T, Khan NA, Mubarak M. Comparison of resistive index and shear-wave elastography in the evaluation of chronic kidney allograft dysfunction. World J Transplant 2024; 14:89255. [PMID: 38576755 PMCID: PMC10989465 DOI: 10.5500/wjt.v14.i1.89255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/18/2024] [Accepted: 02/27/2024] [Indexed: 03/15/2024] Open
Abstract
BACKGROUND Detection of early chronic changes in the kidney allograft is important for timely intervention and long-term survival. Conventional and novel ultrasound-based investigations are being increasingly used for this purpose with variable results. AIM To compare the diagnostic performance of resistive index (RI) and shear wave elastography (SWE) in the diagnosis of chronic fibrosing changes of kidney allograft with histopathological results. METHODS This is a cross-sectional and comparative study. A total of 154 kidney transplant recipients were included in this study, which was conducted at the Departments of Transplantation and Radiology, Sindh Institute of Urology and Transplan tation, Karachi, Pakistan, from August 2022 to February 2023. All consecutive patients with increased serum creatinine levels and reduced glomerular filtration rate (GFR) after three months of transplantation were enrolled in this study. SWE and RI were performed and the findings of these were evaluated against the kidney allograft biopsy results to determine their diagnostic utility. RESULTS The mean age of all patients was 35.32 ± 11.08 years. Among these, 126 (81.8%) were males and 28 (18.2%) were females. The mean serum creatinine in all patients was 2.86 ± 1.68 mg/dL and the mean estimated GFR was 35.38 ± 17.27 mL/min/1.73 m2. Kidney allograft biopsy results showed chronic changes in 55 (37.66%) biopsies. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of SWE for the detection of chronic allograft damage were 93.10%, 96.87%%, 94.73%, and 95.87%, respectively, and the diagnostic accuracy was 95.45%. For RI, the sensitivity, specificity, PPV, and NPV were 76.92%, 83.33%, 70.17%, and 87.62%, respectively, and the diagnostic accuracy was 81.16%. CONCLUSION The results from this study show that SWE is more sensitive and specific as compared to RI in the evaluation of chronic allograft damage. It can be of great help during the routine follow-up of kidney transplant recipients for screening and early detection of chronic changes and selecting patients for allograft biopsy.
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Affiliation(s)
- Ameet Kumar Jesrani
- Department of Radiology, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan
| | - Syed M Faiq
- Department of Radiology, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan
| | - Rahma Rashid
- Department of Pathology, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan
| | - Tariq Ali Kalwar
- Department of Transplantation, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan
| | - Rehan Mohsin
- Department of Urology, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan
| | - Tahir Aziz
- Department of Transplantation, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan
| | - Nida Amin Khan
- Department of Radiology, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan
| | - Muhammed Mubarak
- Department of Pathology, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan
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2
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Ng KH, Wong JHD, Leong SS. Shear wave elastography in chronic kidney disease - the physics and clinical application. Phys Eng Sci Med 2024; 47:17-29. [PMID: 38078996 DOI: 10.1007/s13246-023-01358-w] [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: 12/16/2022] [Accepted: 11/15/2023] [Indexed: 03/26/2024]
Abstract
Chronic kidney disease is a leading public health problem worldwide. The global prevalence of chronic kidney disease is nearly five hundred million people, with almost one million deaths worldwide. Estimated glomerular filtration rate, imaging such as conventional ultrasound, and histopathological findings are necessary as each technique provides specific information which, when taken together, may help to detect and arrest the development of chronic kidney disease, besides managing its adverse outcomes. However, estimated glomerular filtration rate measurements are hampered by substantial error margins while conventional ultrasound involves subjective assessment. Although histopathological assessment is the best tool for evaluating the severity of the renal pathology, it may lead to renal insufficiency and haemorrhage if complications occurred. Ultrasound shear wave elastography, an emerging imaging that quantifies tissue stiffness non-invasively has gained interest recently. This method applies acoustic force pulses to generate shear wave within the tissue that propagate perpendicular to the main ultrasound beam. By measuring the speed of shear wave propagation, the tissue stiffness is estimated. This paper reviews the literature and presents our combined experience and knowledge in renal shear wave elastography research. It discusses and highlights the confounding factors on shear wave elastography, current and future possibilities in ultrasound renal imaging and is not limited to new sophisticated techniques.
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Affiliation(s)
- Kwan Hoong Ng
- Department of Biomedical Imaging, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
- Faculty of Medicine and Health Sciences, UCSI University, Port Dickson, Negeri Sembilan, Malaysia
| | - Jeannie Hsiu Ding Wong
- Department of Biomedical Imaging, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Sook Sam Leong
- Centre for Medical Imaging Studies, Faculty of Health Sciences, Universiti Teknologi MARA Selangor, Selangor, Malaysia.
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Gonçalves LM, Forte GC, Holz TG, Libermann LL, Figueiredo CEPD, Hochhegger B. Shear wave elastography and Doppler ultrasound in kidney transplant recipients. Radiol Bras 2022; 55:19-23. [PMID: 35210660 PMCID: PMC8864684 DOI: 10.1590/0100-3984.2020.0148] [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: 10/02/2020] [Accepted: 03/23/2021] [Indexed: 11/21/2022] Open
Abstract
Objective To evaluate the association between shear wave elastography parameters and arterial
resistance in kidney transplant recipients. Materials and Methods This was a prospective cross-sectional study involving consecutive adult kidney transplant
recipients. All patients underwent color Doppler to evaluate the resistive index (RI) and
ultrasound shear wave elastography for the quantification of renal allograft stiffness. Results We evaluated 55 patients, of whom 9 (16.4%) had an RI defined as abnormal (≥ 0.79)
and 46 (83.6%) had an RI defined as normal (< 0.79). The mean age was higher in the
abnormal RI group than in the normal RI group (68.0 ± 8.6 years vs. 42.6 ± 14.1
years; p < 0.001), as was the mean shear wave velocity (2.6 ± 0.4
m/s vs. 2.2 ± 0.4 m/s; p = 0.013). Multivariate analysis identified
two independent predictors of arterial resistance: age (OR = 1.169; 95% CI: 1.056 to 1.294;
p = 0.003) and shear wave velocity (OR = 17.1; 95% CI: 1.137 to 257.83;
p = 0.040). Conclusion We observed an association between rigidity in the cortex of the transplanted kidney, as
evaluated by shear wave elastography, and arterial resistance, as evaluated by color Doppler,
in kidney transplant recipients.
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Affiliation(s)
| | | | - Tiago Garcia Holz
- Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Brazil
| | | | | | - Bruno Hochhegger
- Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Brazil
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4
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Minami Y, Ogura I. Quantitative analysis of masseter muscle hardness with shear-wave elastography: Preliminary study on comparison between during rest and contraction in young adults. JOURNAL OF ORAL AND MAXILLOFACIAL RADIOLOGY 2022. [DOI: 10.4103/jomr.jomr_3_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Balch JA, Delitto D, Tighe PJ, Zarrinpar A, Efron PA, Rashidi P, Upchurch GR, Bihorac A, Loftus TJ. Machine Learning Applications in Solid Organ Transplantation and Related Complications. Front Immunol 2021; 12:739728. [PMID: 34603324 PMCID: PMC8481939 DOI: 10.3389/fimmu.2021.739728] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 08/25/2021] [Indexed: 11/13/2022] Open
Abstract
The complexity of transplant medicine pushes the boundaries of innate, human reasoning. From networks of immune modulators to dynamic pharmacokinetics to variable postoperative graft survival to equitable allocation of scarce organs, machine learning promises to inform clinical decision making by deciphering prodigious amounts of available data. This paper reviews current research describing how algorithms have the potential to augment clinical practice in solid organ transplantation. We provide a general introduction to different machine learning techniques, describing their strengths, limitations, and barriers to clinical implementation. We summarize emerging evidence that recent advances that allow machine learning algorithms to predict acute post-surgical and long-term outcomes, classify biopsy and radiographic data, augment pharmacologic decision making, and accurately represent the complexity of host immune response. Yet, many of these applications exist in pre-clinical form only, supported primarily by evidence of single-center, retrospective studies. Prospective investigation of these technologies has the potential to unlock the potential of machine learning to augment solid organ transplantation clinical care and health care delivery systems.
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Affiliation(s)
- Jeremy A Balch
- Department of Surgery, University of Florida Health, Gainesville, FL, United States
| | - Daniel Delitto
- Department of Surgery, Johns Hopkins University, Baltimore, MD, United States
| | - Patrick J Tighe
- Department of Anesthesiology, University of Florida Health, Gainesville, FL, United States.,Department of Orthopedics, University of Florida Health, Gainesville, FL, United States.,Department of Information Systems/Operations Management, University of Florida Health, Gainesville, FL, United States
| | - Ali Zarrinpar
- Department of Surgery, University of Florida Health, Gainesville, FL, United States
| | - Philip A Efron
- Department of Surgery, University of Florida Health, Gainesville, FL, United States
| | - Parisa Rashidi
- Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States.,Department of Computer and Information Science and Engineering University of Florida, Gainesville, FL, United States.,Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL, United States.,Precision and Intelligent Systems in Medicine (PrismaP), University of Florida, Gainesville, FL, United States
| | - Gilbert R Upchurch
- Department of Surgery, University of Florida Health, Gainesville, FL, United States
| | - Azra Bihorac
- Precision and Intelligent Systems in Medicine (PrismaP), University of Florida, Gainesville, FL, United States.,Department of Medicine, University of Florida Health, Gainesville, FL, United States
| | - Tyler J Loftus
- Department of Surgery, University of Florida Health, Gainesville, FL, United States.,Precision and Intelligent Systems in Medicine (PrismaP), University of Florida, Gainesville, FL, United States
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Elastography: a surrogate marker of renal allograft fibrosis - quantification by shear-wave technique. Pol J Radiol 2021; 86:e151-e156. [PMID: 33828625 PMCID: PMC8018265 DOI: 10.5114/pjr.2021.104582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/06/2020] [Indexed: 11/29/2022] Open
Abstract
Purpose Renal fibrosis is the most common cause of allograft failure in kidney transplantations. Evaluation of renal abnormalities has progressed considerably over the past years. Currently, the diagnosis of intrarenal fibrosis and quantification of its development with non-invasive assessment tools is possible. This may help in early detection of renal allograft dysfunction. This study sought to assess the efficacy of 2D real-time shear-wave elastography (SWE) in the quantitative measurement of renal allograft dysfunction. Methods A total of 172 patients were included in our study. SWE was performed in all these patients just before renal allograft biopsy. The cortical elasticity was assessed and described in terms of Young’s modulus (kPa). Banff histopathological grading obtained from transplant kidney tissue biopsy was taken as the reference standard. The potential correlation between SWE scores and Banff classification was performed. Results There was a significant correlation between the Banff grade and mean SWE score, with a correlation coefficient of 0.665 (p < 0.001). The individual correlation coefficients of interstitial fibrosis and tubular atrophy with mean SWE score stood at 0.667 and 0.649 respectively (p < 0.001). The correlation of resistive indices was insignificant when compared to mean polar SWE score in respective poles and the Banff grading of fibrosis. Conclusions Renal stiffness quantified by 2D SWE showed significant correlation with histopathological renal fibrosis. Thus, the study suggests that shear-wave elastography could be used as a surrogate marker for early detection of renal fibrosis.
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Qi R, Yang C, Zhu T. Advances of Contrast-Enhanced Ultrasonography and Elastography in Kidney Transplantation: From Microscopic to Microcosmic. ULTRASOUND IN MEDICINE & BIOLOGY 2021; 47:177-184. [PMID: 33143970 DOI: 10.1016/j.ultrasmedbio.2020.07.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/02/2020] [Accepted: 07/22/2020] [Indexed: 06/11/2023]
Abstract
Kidney transplantation is the best choice for patients with end-stage renal disease. To date, allograft biopsy remains the gold standard for revealing pathologic changes and predicting long-term outcomes. However, the invasive nature of transplant biopsy greatly limits its application. Ultrasound has been a first-line examination for evaluating kidney allografts for a long time. Advances in ultrasound in recent years, especially the growing number of studies in elastography and contrast-enhanced ultrasonography (CEUS), have shed new light on its application in kidney transplantation. Elastography, including strain elastography and shear wave elastography, is used mainly to assess allograft stiffness and, thus, predict renal fibrosis. CEUS has been used extensively in evaluating blood microperfusion, assessing acute kidney injury and detecting different complications after transplantation. Requiring the use of microbubbles also makes CEUS a novel method of gene transfer and drug delivery, enabling promising targeted diagnosis and therapy. In this review, we summarize the advances of elastography and CEUS in kidney transplantation and evaluate their potential efficiency in becoming a better complement to or even substitute for transplant biopsy in the future.
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Affiliation(s)
- Ruochen Qi
- Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China; Shanghai Medical College, Fudan University, Shanghai, China; Shanghai Key Laboratory of Organ Transplantation, Shanghai, China
| | - Cheng Yang
- Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China; Shanghai Key Laboratory of Organ Transplantation, Shanghai, China
| | - Tongyu Zhu
- Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China; Shanghai Key Laboratory of Organ Transplantation, Shanghai, China.
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8
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El-Motaal AMA, Dawoud RM, Sherif MF, Eldiasty TA. Role of ultrasound, Color duplex Doppler and sono-elastography in the evaluation of renal allograft complications. THE EGYPTIAN JOURNAL OF RADIOLOGY AND NUCLEAR MEDICINE 2019. [DOI: 10.1186/s43055-019-0079-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Renal transplantation could be considered for patients with end-stage renal disease. Ultrasonography is the imaging method chosen for renal allograft evaluation early in the postoperative period. Sono-elastography is used to estimate tissue stiffness. This study aimed to assess the correlation between sono-elastography and renal allograft histopathology in patients who had transplanted kidney and determine the efficacy of grayscale ultrasound, sono-elastography, and color duplex in evaluation renal allograft complications and correlation with renal function.
Results
Forty patients (26 males and 14 females) who underwent renal transplantation were included. Their ages ranging from 10:52 years; they all subjected to ultrasound, color Doppler, sono-elastography, and histopathology. The studded patients were divided into 3 groups according to histopathology: patient with normal results, patients with ATI, and patients with CAI. The difference between the mean elasticity values between the three groups was statistically highly significant (p value < 0.001) with high specificity, sensitivity, and accuracy in differentiating ATI and normal groups and also CAI and normal groups, while the lowest sensitivity noticed in differentiating between ATI and CAI groups that is mean elasticity was good to differentiating between ATI and normal groups and also between CAI and normal groups while it was less in differentiating between ATI and CAI groups. As regards the RI, the highest sensitivity of the RI was in differentiating ATI and normal with high sensitivity, specificity, and accuracy, and the lowest sensitivity, specificity, and accuracy of RI were in differentiating CAI and normal groups.
Conclusion
Transplanted renal allograft could be assessed by combined US, color duplex Doppler, and sono-elastography examination; also we can detect posttransplant complications early. Sono-elastography could be an efficient noninvasive method to diagnose and monitor kidney allograft rejection and follow-up of the renal allograft, which may give a further and possibly earlier prognostic index for chronic dysfunction in addition to serum creatinine.
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9
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Hossain MM, Detwiler RK, Chang EH, Caughey MC, Fisher MW, Nichols TC, Merricks EP, Raymer RA, Whitford M, Bellinger DA, Wimsey LE, Gallippi CM. Mechanical Anisotropy Assessment in Kidney Cortex Using ARFI Peak Displacement: Preclinical Validation and Pilot In Vivo Clinical Results in Kidney Allografts. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2019; 66:551-562. [PMID: 30106723 PMCID: PMC8232042 DOI: 10.1109/tuffc.2018.2865203] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The kidney is an anisotropic organ, with higher elasticity along versus across nephrons. The degree of mechanical anisotropy in the kidney may be diagnostically relevant if properly exploited; however, if improperly controlled, anisotropy may confound stiffness measurements. The purpose of this study is to demonstrate the clinical feasibility of acoustic radiation force (ARF)-induced peak displacement (PD) measures for both exploiting and obviating mechanical anisotropy in the cortex of human kidney allografts, in vivo. Validation of the imaging methods is provided by preclinical studies in pig kidneys, in which ARF-induced PD values were significantly higher ( , Wilcoxon) when the transducer executing asymmetric ARF was oriented across versus along the nephrons. The ratio of these PD values obtained with the transducer oriented across versus along the nephrons strongly linearly correlated ( R2 = 0.95 ) to the ratio of shear moduli measured by shear wave elasticity imaging. On the contrary, when a symmetric ARF was implemented, no significant difference in PD was observed ( p > 0.01 ). Similar results were demonstrated in vivo in the kidney allografts of 14 patients. The symmetric ARF produced PD measures with no significant difference ( p > 0.01 ) between along versus across alignments, but the asymmetric ARF yielded PD ratios that remained constant over a six-month observation period post-transplantation, consistent with stable serum creatinine level and urine protein-to-creatinine ratio in the same patient population ( p > 0.01 ). The results of this pilot in vivo clinical study suggest the feasibility of 1) implementing symmetrical ARF to obviate mechanical anisotropy in the kidney cortex when anisotropy is a confounding factor and 2) implementing asymmetric ARF to exploit mechanical anisotropy when mechanical anisotropy is a potentially relevant biomarker.
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Hossain MM, Selzo MR, Hinson RM, Baggesen LM, Detwiler RK, Chong WK, Burke LM, Caughey MC, Fisher MW, Whitehead SB, Gallippi CM. Evaluating Renal Transplant Status Using Viscoelastic Response (VisR) Ultrasound. ULTRASOUND IN MEDICINE & BIOLOGY 2018; 44:1573-1584. [PMID: 29754702 PMCID: PMC6026561 DOI: 10.1016/j.ultrasmedbio.2018.03.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 02/20/2018] [Accepted: 03/16/2018] [Indexed: 05/03/2023]
Abstract
Chronic kidney disease is most desirably and cost-effectively treated by renal transplantation, but graft survival is a major challenge. Although irreversible graft damage can be averted by timely treatment, intervention is delayed when early graft dysfunction goes undetected by standard clinical metrics. A more sensitive and specific parameter for delineating graft health could be the viscoelastic properties of the renal parenchyma, which are interrogated non-invasively by Viscoelastic Response (VisR) ultrasound, a new acoustic radiation force (ARF)-based imaging method. Assessing the performance of VisR imaging in delineating histologically confirmed renal transplant pathologies in vivo is the purpose of the study described here. VisR imaging was performed in patients with (n = 19) and without (n = 25) clinical indication for renal allograft biopsy. The median values of VisR outcome metrics (τ, relative elasticity [RE] and relative viscosity [RV]) were calculated in five regions of interest that were manually delineated in the parenchyma (outer, center and inner) and in the pelvis (outer and inner). The ratios of a given VisR metric for all possible region-of-interest combinations were calculated, and the corresponding ratios were statistically compared between biopsied patients subdivided by diagnostic categories versus non-biopsied, control allografts using the two-sample Wilcoxon test (p <0.05). Although τ ratios non-specifically differentiated allografts with vascular disease, tubular/interstitial scarring, chronic allograft nephropathy and glomerulonephritis from non-biopsied control allografts, RE distinguished only allografts with vascular disease and tubular/interstitial scarring, and RV distinguished only vascular disease. These results suggest that allografts with scarring and vascular disease can be identified using non-invasive VisR RE and RV metrics.
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Affiliation(s)
- Md Murad Hossain
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Mallory R Selzo
- Ultrasound Business Unit, Siemens Healthcare, Issaquah, Washington, USA
| | - Robert M Hinson
- Department of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Leslie M Baggesen
- Kaiser Permanente, Northern California Regional Program Office, Berkeley, California, USA
| | - Randal K Detwiler
- Department of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Wui K Chong
- Department of Radiology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Lauren M Burke
- Department of Radiology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Melissa C Caughey
- Department of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Melrose W Fisher
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Sonya B Whitehead
- Department of Radiology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Caterina M Gallippi
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA; Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, North Carolina, USA; Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, North Carolina, USA.
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Rezajoo S, Sharafat AR. Robust Estimation of Displacement in Real-Time Freehand Ultrasound Strain Imaging. IEEE TRANSACTIONS ON MEDICAL IMAGING 2018; 37:1664-1677. [PMID: 29969417 DOI: 10.1109/tmi.2018.2795085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We present a novel and efficient approach for robust estimation of displacement in real-time strain imaging for freehand ultrasound elastography by utilizing pre- and post-deformation ultrasound images. We define a quality factor for image lines and find the line with the highest value of quality factor to serve as the seed line for generating the displacement map. We also develop an analytical framework for coarse-to-fine displacement estimation, obtain an initial estimate of the seed line's displacement with subsample precision, and propagate it to the entire image to obtain a high quality strain image. Our fast strategy for estimating the seed line's displacement enables us to enhance the robustness without sacrificing the speed by identifying a new seed line when the quality falls below a given threshold. This is more efficient than the existing approaches that utilize multiple seed lines to improve robustness. Simulations, phantom experiments, and clinical studies show high signal-to-noise-ratio and contrast-to-noise-ratio values in our method for a wide range of average strain levels (1%-10%). Phantom experiments also demonstrate that our method is robust against corrupt and decorrelated data. Our method is superior to the existing real-time methods as it can produce high-quality strain images for up to 10% average strain levels at the rate of 20 frames/s on conventional CPUs.
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12
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Early HM, Cheang EC, Aguilera JM, Hirschbein JSW, Fananapazir G, Wilson MD, McGahan JP. Utility of Shear Wave Elastography for Assessing Allograft Fibrosis in Renal Transplant Recipients: A Pilot Study. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2018; 37:1455-1465. [PMID: 29143363 DOI: 10.1002/jum.14487] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 08/28/2017] [Accepted: 08/29/2017] [Indexed: 05/28/2023]
Abstract
OBJECTIVES To evaluate the utility of ultrasound-based shear wave elastography (SWE) as a noninvasive method to accurately detect and potentially stage the severity of renal allograft fibrosis and assess its user reproducibility. METHODS In this Institutional Review Board-approved, Health Insurance Portability and Accountability Act-compliant prospective study, 70 renal transplant recipients underwent an SWE evaluation of their allograft followed directly by biopsy. Two radiologists performed separate SWE measurement acquisitions and the mean, median, and standard deviation of 10 SWE measurements, obtained separately within the cortex and the medulla, were automatically computed. Each patient's SWE results were subsequently compared to their histologic fibrosis scores. The Fisher exact test and univariate logistic regression models were fit to test for associations between the presence of fibrosis (yes/no) as well as categorical SWE results based on the fibrosis severity, ranging from F0 (no fibrosis) to F3 (severe fibrosis), correlating with histologic scores according to the 2007 Banff classification system. Interobserver and intraobserver correlations were also examined. RESULTS Our median medulla SWE values reached statistical significance (P = .04) in association with fibrosis. Furthermore, for every unit increase in the median medulla SWE measurement, the odds of fibrosis increased by approximately 20%. No statistical significance was found for mean cortical, median cortical, or mean medullary SWE values (P = .32, .37, and .06, respectively) in association with fibrosis. CONCLUSIONS The use of SWE for assessing renal allograft fibrosis is challenging but promising. Further investigation with a larger sample size remains to validate our initial results and establish clinical relevance.
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Affiliation(s)
- Heather M Early
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Ellen C Cheang
- Department of Radiology, University of California Davis Medical Center, Sacramento, California, USA
| | - Jorge M Aguilera
- Department of Radiology, University of California Davis Medical Center, Sacramento, California, USA
| | - Jonah S W Hirschbein
- Department of Radiology, University of California Davis Medical Center, Sacramento, California, USA
| | - Ghaneh Fananapazir
- Department of Radiology, University of California Davis Medical Center, Sacramento, California, USA
| | - Machelle D Wilson
- Department of Public Health Sciences, Division of Biostatistics, University of California Davis School of Medicine, Sacramento, California, USA
| | - John P McGahan
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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13
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Ghonge NP, Mohan M, Kashyap V, Jasuja S. Renal Allograft Dysfunction: Evaluation with Shear-wave Sonoelastography. Radiology 2018; 288:146-152. [PMID: 29634441 DOI: 10.1148/radiol.2018170577] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Purpose To evaluate whether shear-wave sonoelastography can help differentiate stable renal allograft from acute allograft dysfunction and chronic allograft dysfunction and to correlate shear-wave sonoelastography measurements with resistive index (RI), serum creatinine level, estimated glomerular filtration rate (eGFR) obtained with the Nankivell equation, and biopsy findings. Materials and Methods A prospective study of 60 patients who had undergone renal transplantation was conducted between October 2014 and March 2016. Patients were classified as having stable allograft, acute allograft dysfunction, or chronic allograft dysfunction on the basis of clinical parameters. Mean parenchymal stiffness was compared. The Banff score was used wherever applicable. Receiver operating characteristic curves were drawn to evaluate the feasibility of differentiation. Results Thirty patients had graft dysfunction (acute in 19 patients and chronic in 11). Mean parenchymal stiffness values in stable allograft, acute allograft dysfunction, and chronic allograft dysfunction were 8.51 kPa ± 2.44, 11.06 kPa ± 2.91, and 24.50 kPa ± 4.49, respectively (stable vs acute dysfunction, P = .010; stable vs chronic dysfunction, P < .001; acute sysfunction vs chronic dysfunction, P < .001). The allograft parenchymal stiffness values for patients with Banff grade I (mild interstitial fibrosis and tubular atrophy) differed significantly from those with Banff grade II (moderate interstitial fibrosis and tubular atrophy) (P = .02). Parenchymal stiffness showed a negative correlation with eGFR (r = -0.725; P < .001) and a positive correlation with RI (r = 0.562; P < .001) and serum creatinine level (r = 0.714; P < .001). The sensitivity was 73.68% and specificity was 80% in the differentiation of stable graft from acute graft dysfunction (threshold value, 10.11 kPa). Conclusion Shear-wave sonoelastographic evaluation of renal parenchymal stiffness may help differentiate stable allograft from acute and chronic allograft dysfunction. The inverse correlation of parenchymal stiffness with eGFR and positive correlation with RI and serum creatinine level show that shear-wave sonoelastography may reflect functional status of the renal allograft.
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Affiliation(s)
- Nitin P Ghonge
- From the Departments of Radiology (N.P.G., M.M.), Pathology (V.K.), and Nephrology (S.J.), Indraprastha Apollo Hospital, Delhi Mathura Rd, Sarita Vihar, New Delhi 110076, India
| | - Mohita Mohan
- From the Departments of Radiology (N.P.G., M.M.), Pathology (V.K.), and Nephrology (S.J.), Indraprastha Apollo Hospital, Delhi Mathura Rd, Sarita Vihar, New Delhi 110076, India
| | - Vikas Kashyap
- From the Departments of Radiology (N.P.G., M.M.), Pathology (V.K.), and Nephrology (S.J.), Indraprastha Apollo Hospital, Delhi Mathura Rd, Sarita Vihar, New Delhi 110076, India
| | - Sanjiv Jasuja
- From the Departments of Radiology (N.P.G., M.M.), Pathology (V.K.), and Nephrology (S.J.), Indraprastha Apollo Hospital, Delhi Mathura Rd, Sarita Vihar, New Delhi 110076, India
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Salavati M, Akhbari B, Ebrahimi Takamjani I, Ezzati K, Haghighatkhah H. Reliability of the Upper Trapezius Muscle and Fascia Thickness and Strain Ratio Measures by Ultrasonography and Sonoelastography in Participants With Myofascial Pain Syndrome. J Chiropr Med 2017; 16:316-323. [PMID: 29276464 DOI: 10.1016/j.jcm.2017.06.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 06/20/2017] [Accepted: 06/28/2017] [Indexed: 01/26/2023] Open
Abstract
Objective The purpose of this study was to assess the intra- and interexaminer reliability of the upper trapezius muscle and fascia thickness measured by ultrasonography imaging and strain ratio by sonoelastography in participants with myofascial pain syndrome. Methods Thirty-two upper trapezius muscles were assessed. Two examiners measured the upper trapezius thickness and strain ratio 3 times by ultrasonography and sonoelastography independently in the test session. The retest session was completed 6 to 8 days later. Results A total of 87.5% of participants had trigger points on the right side, and 22.5% had trigger points on the left side. For the test session, the average upper trapezius thickness, fascia thickness, and strain ratio measured by first and second examiners were 11.86 mm and 11.56 mm, 1.23 mm and 1.25 mm, and 0.94 and 0.99, respectively. For the retest session, the previously mentioned parameters obtained by first and second examiners were 11.76 mm and 11.39 mm, 1.27 mm and 1.29 mm, and 0.96 and 0.99, respectively. The intraclass correlation coefficients indicated good to excellent reliability for both within-intraexaminer (0.78-0.96) and between-intraexaminer (0.75-0.98) measurements. Also, the intraclass correlation coefficients and standard errors of measurement of interexaminer reliability ranged between 0.88 to 0.93 and 0.05 to 0.44 for both muscle and fascia thickness and 0.70 to 0.75 and 0.04 to 0.20 for strain ratio of upper trapezius, respectively. Conclusion Upper trapezius thickness measurements by ultrasonography and strain ratio by sonoelastography are reliable methods in participants with myofascial pain syndrome.
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Affiliation(s)
- Mahyar Salavati
- University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Behnam Akhbari
- University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Ismail Ebrahimi Takamjani
- Physiotherapy Department, Rehabilitation Faculty of Iran University of Medical Sciences, Tehran, Iran
| | - Kamran Ezzati
- Physiotherapy Department, Guilan University of Medical Sciences, Rasht, Iran
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Wang Z, Yang H, Suo C, Wei J, Tan R, Gu M. Application of Ultrasound Elastography for Chronic Allograft Dysfunction in Kidney Transplantation. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2017; 36:1759-1769. [PMID: 28503746 DOI: 10.1002/jum.14221] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 11/28/2016] [Indexed: 05/21/2023]
Abstract
Interstitial fibrosis is the main characteristic of chronic allograft dysfunction, which remains the key factor affecting long-term allograft survival after kidney transplantation. Ultrasound elastography (UE), including real-time elastography, transient elastography, and acoustic radiation force impulse, has been applied widely in breast, thyroid, and liver diseases, especially in the assessment of liver fibrosis. Recently, numerous studies have reported the efficacy of UE methods in evaluating renal allograft fibrosis. This review aims to investigate the clinical applications, limitations, and future roles of UE in current clinical practice in light of changing management paradigms. In current clinical practice, UE methods, especially transient elastographic measurement, appear to be useful for ruling out fibrosis but do not have sufficient accuracy to distinguish between various stages of allograft fibrosis. Moreover, there remain considerable issues to be solved for the application of UE in kidney transplantation. Thus, UE methods cannot replace the crucial role of renal allograft biopsy in the diagnosis and evaluation of allograft fibrosis in kidney transplantation. Perhaps UE methods could be of more importance in the long-term observation and evaluation of allograft fibrosis during follow-up.
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Affiliation(s)
- Zijie Wang
- Department of Urology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Haiwei Yang
- Department of Urology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Chuanjian Suo
- Department of Pharmacy, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Jifu Wei
- Department of Pharmacy, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Ruoyun Tan
- Department of Urology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Min Gu
- Department of Urology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
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Wang HK, Lai YC, Lin YH, Chiou HJ, Chou YH. Acoustic Radiation Force Impulse Imaging of the Transplant Kidney: Correlation Between Cortical Stiffness and Arterial Resistance in Early Post-transplant Period. Transplant Proc 2017; 49:1001-1004. [DOI: 10.1016/j.transproceed.2017.03.045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Singh H, Panta OB, Khanal U, Ghimire RK. Renal Cortical Elastography: Normal Values and Variations. J Med Ultrasound 2017; 25:215-220. [PMID: 30065495 PMCID: PMC6029337 DOI: 10.1016/j.jmu.2017.04.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 03/22/2017] [Indexed: 12/20/2022] Open
Abstract
Introduction Renal cortical elastography has shown conflicting but promising results in evaluation of chronic kidney disease and other renal disorders. The purpose of this study was to establish a normogram of renal cortical elasticity values and assess their variation between right and left kidney and their relation with age, gender, body mass index, renal dimensions and skin to cortex distance. Methods The study was a hospital based cross sectional study performed at Tribhuvan University Teaching Hospital, a tertiary care center in Kathmandu, Nepal. All individuals referred for Ultrasound from General Health Check up clinic were included in the study. Patient with abnormal ultrasound findings and abnormal renal function test were excluded from the study. Renal morphometry including length, cortical thickness, and skin to cortex distance were measured in B mode imaging and renal cortical elastography was measured with region of interest box of 1 × 0.5 cm. All analyses were done using Statistical Package for Social Sciences 20.0 soft ware. Results A total of 95 individuals who met the inclusion criteria were included in the study. The mean values of right and left renal cortical shear wave velocity were 1.49 ± 0.19 m/s and 1.54 ± 0.19 m/s respectively. Statistical significant difference was observed between the renal cortical shear wave velocity of right and left kidney. The renal shear wave velocity was seen to decrease with age, however the correlation was not statistically significant. No significant difference was also noted in renal shear wave velocity among various sex or Body mass index groups. Statistically significant negative correlation was noted between skin to cortex distance and renal cortical shear wave velocities. However no statistically significant correlation was noted between renal dimensions and renal cortical shear wave velocities. Conclusions The normal cortical elasticity values in terms of shear wave velocity of right and left kidney were established. Renal elasticity is independent of the age, gender, Body mass index and renal dimensions.
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Affiliation(s)
- Harsh Singh
- Department of Radiodiagnosis, King George Medical University, Lucknow, India
| | - Om Biju Panta
- Department of Intervention Radiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Thailand
| | - Umesh Khanal
- Department of Radiology and Imaging, Tribhuvan University Teaching Hospital, Nepal
| | - Ram Kumar Ghimire
- Department of Radiology and Imaging, Tribhuvan University Teaching Hospital, Nepal
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Multifrequency Magnetic Resonance Elastography for the Assessment of Renal Allograft Function. Invest Radiol 2016; 51:591-5. [DOI: 10.1097/rli.0000000000000271] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Menzilcioglu MS, Duymus M, Citil S, Gungor G, Saglam M, Gungor O, Boysan SN, Sarıca A, Avcu S. The comparison of resistivity index and strain index values in the ultrasonographic evaluation of chronic kidney disease. Radiol Med 2016; 121:681-7. [PMID: 27290720 DOI: 10.1007/s11547-016-0652-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 05/23/2016] [Indexed: 12/13/2022]
Abstract
OBJECTIVES Chronic kidney disease (CKD) is a disorder progressing to end-stage kidney failure. Early diagnosis and treatment are important for medical care. The aim of this prospective study was to define the strain index (SI) and resistivity index (RI) values in the same CKD group for each kidney separately at the same time, and also to compare the efficacy of SI and RI in the differentiation of normal population and CKD patients. MATERIALS AND METHODS Toshiba Aplio 500 USG device and 3.5-5 MHz convex probe were used for USG, CDUSG, and USG elastography examinations. The patients were referred to radiology clinique from nephrology and endocrinology cliniques after GFR calculation. Patients with renal cyst, tumor, or obstructive renal disease were excluded. Healthy volunteers according to laboratory and clinical examinations were selected from non-kidney disease patients. RESULTS A total of 121 CKD (68 men, 53 women) and 40 healthy volunteers (19 men, 21 women) were participated. The mean SI and RI values of CKD were significantly higher than the normal healthy volunteers (p < 0.05). The SI and RI values of right and left kidney did not show any difference in CKD patients (p values were 0.381 for SI and 0.821 for RI). The sensitivity and the specificity of the SI were higher than RI. CONCLUSION The RI and SI values of kidneys in CKD patients were significantly higher than those of apparently normal kidneys. SI was more sensitive than RI in our study. Determining cut-off SI and RI values between normal and damaged renal parenchyma can help in the diagnosis and follow up of CKD patients. ADVANCES IN KNOWLEDGE To the best of our knowledge, this is the first study comparing RI and SI in CKD patients, and SI is found to be more sensitive than RI for the evaluation of CKD.
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Affiliation(s)
| | - Mahmut Duymus
- Department of Radiology, Gazi University School of Medicine, Ankara, Turkey
| | - Serdal Citil
- Clinic of Radiology, Kahramanmaras Necip Fazıl City Hospital, Kahramanmaras, Turkey
| | - Gulay Gungor
- Clinic of Radiology, Kahramanmaras Necip Fazıl City Hospital, Kahramanmaras, Turkey
| | - Mustafa Saglam
- Clinic of Nephrology, Turkey Kahramanmaras Necip Fazıl City Hospital, Kahramanmaras, Turkey
| | - Ozkan Gungor
- Clinic of Nephrology, Turkey Kahramanmaras Necip Fazıl City Hospital, Kahramanmaras, Turkey
| | - Serife Nur Boysan
- Clinic of Endocrinology, Kahramanmaras Necip Fazıl City Hospital, Kahramanmaras, Turkey
| | - Akif Sarıca
- Department of Radiology, Kahramanmaras University School of Medicine, Kahramanmaras, Turkey
| | - Serhat Avcu
- Department of Radiology, Gazi University School of Medicine, Ankara, Turkey
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21
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Irie S, Inoue K, Yoshida K, Mamou J, Kobayashi K, Maruyama H, Yamaguchi T. Speed of sound in diseased liver observed by scanning acoustic microscopy with 80 MHz and 250 MHz. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2016; 139:512-519. [PMID: 26827044 DOI: 10.1121/1.4940126] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In this study, the speed of sound (SOS) of two types of rat livers (eight normal livers, four cirrhotic livers) was measured with a scanning acoustic microscope using two transducers, one of which had an 80-MHz and the other a 250-MHz center frequency. The 250-MHz transducer had a better spatial resolution adapted to studying fiber or hepatic parenchymal cells. In normal livers, averages of the SOS values were from 1598 to 1677 m/s at 80-MHz and from 1568 to 1668 m/s at 250-MHz. In the fiber tissue of cirrhotic livers, averages of the SOS values were from 1645 to 1658 m/s at 80-MHz and from 1610 to 1695 m/s at 250-MHz, while the SOS values in the other tissue of cirrhotic livers ranged from 1644 to 1709 m/s at 80-MHz and from 1641 to 1715 m/s at 250-MHz. In one liver, SOS in fiber tissue was larger than that of tissues without fiber while in others it was lower. The resulting two-dimensional SOS maps provide a unique quantitative insight of liver acoustic microstructures in a healthy liver and in a cirrhotic ones. This study would be helpful to understand the complex relationship between acoustic properties and liver disease including fiber tissue.
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Affiliation(s)
- So Irie
- Graduate School of Engineering, Chiba University, 1-33 Yayoicho, Inage, Chiba, Japan
| | - Kenta Inoue
- Graduate School of Engineering, Chiba University, 1-33 Yayoicho, Inage, Chiba, Japan
| | - Kenji Yoshida
- Center for Frontier Medical Engineering, Chiba University, 1-33 Yayoicho, Inage, Chiba, Japan
| | - Jonathan Mamou
- Lizzi Center for Biomedical Engineering, Riverside Research, 156 William Street, New York, New York 10038, USA
| | - Kazuto Kobayashi
- Honda Electronics Co., Ltd., 20 Koyamazuka, Oiwa-cho, Toyohashi, Japan
| | - Hitoshi Maruyama
- Department of Gastroenterology and Nephrology, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo, Chiba, Japan
| | - Tadashi Yamaguchi
- Center for Frontier Medical Engineering, Chiba University, 1-33 Yayoicho, Inage, Chiba, Japan
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Moreno CC, Mittal PK, Ghonge NP, Bhargava P, Heller MT. Imaging Complications of Renal Transplantation. Radiol Clin North Am 2015; 54:235-49. [PMID: 26896222 DOI: 10.1016/j.rcl.2015.09.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Renal transplant complications are categorized as those related to the transplant vasculature, collecting system, perinephric space, renal parenchyma, and miscellaneous complications including posttransplant lymphoproliferative disorder. Many of these renal transplant complications are diagnosed with imaging. Medical complications including rejection, acute tubular necrosis, and drug toxicity also can impair renal function. These medical complications are typically indistinguishable at imaging, and biopsy may be performed to establish a diagnosis. Normal transplant anatomy, imaging techniques, and the appearances of renal transplant complications at ultrasound, computed tomography, and MR imaging are reviewed.
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Affiliation(s)
- Courtney Coursey Moreno
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1364 Clifton Road, NE, Atlanta, GA 30322, USA.
| | - Pardeep K Mittal
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1364 Clifton Road, NE, Atlanta, GA 30322, USA
| | - Nitin P Ghonge
- Department of Radiology, Indraprastha Apollo Hospitals, Delhi-Mathura Road, New Delhi 110076, India
| | - Puneet Bhargava
- Department of Radiology, VA Puget Sound Health Care System, University of Washington Medical Center, 1959 NE Pacific Street, Room BB308, Box 357115, Seattle, WA 98195-7115, USA
| | - Matthew T Heller
- Department of Radiology, University of Pittsburgh School of Medicine, 200 Lothrop Street, Suite 174E PUH, Pittsburgh, PA 15213, USA
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Ariji Y, Nakayama M, Nishiyama W, Nozawa M, Ariji E. Shear-wave sonoelastography for assessing masseter muscle hardness in comparison with strain sonoelastography: study with phantoms and healthy volunteers. Dentomaxillofac Radiol 2015; 45:20150251. [PMID: 26624000 PMCID: PMC5083954 DOI: 10.1259/dmfr.20150251] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 11/20/2015] [Accepted: 11/24/2015] [Indexed: 12/14/2022] Open
Abstract
UNLABELLED Objectives Shear-wave sonoelastography is expected to facilitate low operator dependency, high reproducibility and quantitative evaluation, whereas there are few reports on available normative values of in vivo tissue in head and neck fields. The purpose of this study was to examine the reliabilities on measuring hardness using shear-wave sonoelastography and to clarify normal values of masseter muscle hardness in healthy volunteers. Methods Phantoms with known hardness ranging from 20 to 140 kPa were scanned with shear-wave sonoelastography, and inter- and intraoperator reliabilities were examined compared with strain sonoelastography. The relationships between the actual and measured hardness were analyzed. The masseter muscle hardness in 30 healthy volunteers was measured using shear-wave sonoelastography. RESULTS The inter- and intraoperator intraclass correlation coefficients were almost perfect. Strong correlations were seen between the actual and measured hardness. The mean hardness of the masseter muscles in healthy volunteers was 42.82 ± 5.56 kPa at rest and 53.36 ± 8.46 kPa during jaw clenching. CONCLUSIONS The hardness measured with shear-wave sonoelastography showed high-level reliability. Shear-wave sonoelastography may be suitable for evaluation of the masseter muscles.
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Affiliation(s)
- Yoshiko Ariji
- Department of Oral and Maxillofacial Radiology, School of Dentistry, Aichi Gakuin University, Nagoya, Japan
| | - Miwa Nakayama
- Division of Oral and Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Wataru Nishiyama
- Department of Oral and Maxillofacial Radiology, School of Dentistry, Aichi Gakuin University, Nagoya, Japan
| | - Michihito Nozawa
- Department of Oral and Maxillofacial Radiology, School of Dentistry, Aichi Gakuin University, Nagoya, Japan
| | - Eiichiro Ariji
- Department of Oral and Maxillofacial Radiology, School of Dentistry, Aichi Gakuin University, Nagoya, Japan
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Gao J, Rubin JM, Weitzel W, Lee J, Dadhania D, Kapur S, Min R. Comparison of Ultrasound Corticomedullary Strain with Doppler Parameters in Assessment of Renal Allograft Interstitial Fibrosis/Tubular Atrophy. ULTRASOUND IN MEDICINE & BIOLOGY 2015; 41:2631-2639. [PMID: 26219696 DOI: 10.1016/j.ultrasmedbio.2015.06.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 06/05/2015] [Accepted: 06/10/2015] [Indexed: 05/28/2023]
Abstract
To compare the capability of ultrasound strain and Doppler parameters in the assessment of renal allograft interstitial fibrosis/tubular atrophy (IF/TA), we prospectively measured ultrasound corticomedullary strain (strain) and intra-renal artery Doppler end-diastolic velocity (EDV), peak systolic velocity (PSV) and resistive index (RI) in 45 renal transplant recipients before their kidney biopsies. We used 2-D speckle tracking to estimate strain, the deformation ratio of renal cortex to medulla produced by external compression using the ultrasound transducer. We also measured Doppler EDV, PSV and RI at the renal allograft inter-lobar artery. Using the Banff scoring system for renal allograft IF/TA, 45 patients were divided into the following groups: group 1 with ≤5% (n = 12) cortical IF/TA; group 2 with 6%-25% (n = 12); group 3 with 26%-50% (n = 11); and group 4 with >50% (n = 10). We performed receiver operating characteristic curve analysis to test the accuracy of these ultrasound parameters and duration of transplantation in determining >26% cortical IF/TA. In our results, strain was statistically significant in all paired groups (all p < 0.005) and inversely correlated with the grade of cortical IF/TA (p < 0.001). However, the difference in PSV and EDV was significant only between high-grade (>26%, including 26%-50% and >50%) and low-grade (≤25%, including <5% and 6%-25%) cortical IF/TA (p < 0.001). RI did not significantly differ in any paired group (all p > 0.05). The areas under the receiver operating characteristic curve for strain, EDV, PSV, RI and duration of transplantation in determining >26% cortical IF/TA were 0.99, 0.94, 0.88, 0.52 and 0.92, respectively. Our results suggest that corticomedullary strain seems to be superior to Doppler parameters and duration of transplantation in assessment of renal allograft cortical IF/TA.
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Affiliation(s)
- Jing Gao
- Department of Radiology, Weill Cornell Medical College, New York, New York, USA.
| | - Jonathan M Rubin
- Department of Radiology, University of Michigan Hospitals, Ann Arbor, Michigan, USA
| | - William Weitzel
- University of Michigan Hospitals, VA Medical Center, Ann Arbor, Michigan, USA
| | - Jun Lee
- Rogosin Institute, Weill Cornell Medical College, New York, New York, USA
| | - Darshana Dadhania
- Rogosin Institute, Weill Cornell Medical College, New York, New York, USA
| | - Sandip Kapur
- Department of Surgery, Weill Cornell Medical College, New York, New York, USA
| | - Robert Min
- Department of Radiology, Weill Cornell Medical College, New York, New York, USA
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Samir AE, Allegretti AS, Zhu Q, Dhyani M, Anvari A, Sullivan DA, Trottier CA, Dougherty S, Williams WW, Babitt JL, Wenger J, Thadhani RI, Lin HY. Shear wave elastography in chronic kidney disease: a pilot experience in native kidneys. BMC Nephrol 2015; 16:119. [PMID: 26227484 PMCID: PMC4521488 DOI: 10.1186/s12882-015-0120-7] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 07/22/2015] [Indexed: 12/17/2022] Open
Abstract
Background There currently is a need for a non-invasive measure of renal fibrosis. We aim to explore whether shear wave elastography (SWE)-derived estimates of tissue stiffness may serve as a non-invasive biomarker that can distinguish normal and abnormal renal parenchymal tissue. Methods Participants with CKD (by estimated GFR) and healthy volunteers underwent SWE. Renal elasticity was estimated as Young’s modulus (YM) in kilopascals (kPa). Univariate Wilcoxon rank-sum tests were used. Results Twenty-five participants with CKD (median GFR 38 mL/min; quartile 1, quartile 3 28, 42) and 20 healthy controls without CKD underwent SWE performed by a single radiologist. CKD was associated with increased median YM (9.40 [5.55, 22.35] vs. 4.40 [3.68, 5.70] kPa; p = 0.002) and higher median intra-subject inter-measurement estimated YM’s variability (4.27 [2.89, 9.90] vs. 1.51 [1.21, 2.05] kPa; p < 0.001). Conclusions SWE-derived estimates of renal stiffness and intra-subject estimated stiffness variability are higher in patients with CKD than in healthy controls. Renal fibrosis is a plausible explanation for the observed difference in YM. Further studies are required to determine the relationship between YM, estimated renal stiffness, and renal fibrosis severity. Electronic supplementary material The online version of this article (doi:10.1186/s12882-015-0120-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Anthony E Samir
- Department of Radiology, Massachusetts General Hospital, Boston, MA, 02114, USA.
| | - Andrew S Allegretti
- Department of Medicine, Division of Nephrology, Massachusetts General Hospital, 185 Cambridge St, Suite 8.216, Boston, MA, 02114, USA.
| | - Qingli Zhu
- Department of Radiology, Massachusetts General Hospital, Boston, MA, 02114, USA.
| | - Manish Dhyani
- Department of Radiology, Massachusetts General Hospital, Boston, MA, 02114, USA.
| | - Arash Anvari
- Department of Radiology, Massachusetts General Hospital, Boston, MA, 02114, USA.
| | - Dorothy A Sullivan
- Department of Medicine, Division of Nephrology, Massachusetts General Hospital, 185 Cambridge St, Suite 8.216, Boston, MA, 02114, USA.
| | - Caitlin A Trottier
- Department of Medicine, Division of Nephrology, Massachusetts General Hospital, 185 Cambridge St, Suite 8.216, Boston, MA, 02114, USA.
| | - Sarah Dougherty
- Department of Medicine, Division of Nephrology, Massachusetts General Hospital, 185 Cambridge St, Suite 8.216, Boston, MA, 02114, USA.
| | - Winfred W Williams
- Department of Medicine, Division of Nephrology, Massachusetts General Hospital, 185 Cambridge St, Suite 8.216, Boston, MA, 02114, USA.
| | - Jodie L Babitt
- Department of Medicine, Division of Nephrology, Massachusetts General Hospital, 185 Cambridge St, Suite 8.216, Boston, MA, 02114, USA.
| | - Julia Wenger
- Department of Medicine, Division of Nephrology, Massachusetts General Hospital, 185 Cambridge St, Suite 8.216, Boston, MA, 02114, USA.
| | - Ravi I Thadhani
- Department of Medicine, Division of Nephrology, Massachusetts General Hospital, 185 Cambridge St, Suite 8.216, Boston, MA, 02114, USA.
| | - Herbert Y Lin
- Department of Medicine, Division of Nephrology, Massachusetts General Hospital, 185 Cambridge St, Suite 8.216, Boston, MA, 02114, USA.
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Bob F, Bota S, Sporea I, Sirli R, Popescu A, Schiller A. Relationship between the estimated glomerular filtration rate and kidney shear wave speed values assessed by acoustic radiation force impulse elastography: a pilot study. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2015; 34:649-54. [PMID: 25792580 DOI: 10.7863/ultra.34.4.649] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
OBJECTIVES The aim of the study was to establish the relationship between the estimated glomerular filtration rate (GFR) and kidney shear wave speed values assessed by acoustic radiation force impulse (ARFI) elastography. METHODS Our study included 104 patients with or without chronic kidney disease in which the kidney shear wave speed was evaluated by ARFI elastography and correlated with the estimated GFR. Five ARFI measurements were performed in the parenchyma of each kidney. A median value expressed as meters per second was calculated. RESULTS Five valid ARFI elastographic measurements were obtained in the right kidney in all patients and in the left kidney in 97.1% of patients. The mean kidney shear wave speed values ± SD in the right and left kidneys were similar: 2.17 ± 0.81 versus 2.06 ± 0.75 m/s (P = .30). The mean kidney shear wave speed decreased with the decrease in the estimated GFR. Statistically significant differences were obtained only when kidney shear wave speed values obtained in patients with an estimated GFR of greater than 90 mL/min/1.73 m(2) were compared to values in patients with stage 4 (estimated GFR, 15-29 mL/min/1.73 m(2)) and stage 5 (estimated GFR, <15 mL/min/1.73 m(2)) chronic kidney disease: 2.32 ± 0.83 versus 1.62 ± 0.75 m/s (P = .03) and 2.32 ± 0.83 versus 1.66 ± 0.72 m/s (P = .04), respectively. For a cutoff value of 2.26 m/s or lower, kidney shear wave speed had 86.7% sensitivity, 48.3% specificity, a 22.1% positive predictive value, and a 95.6% negative predictive value (area under the receiver operating characteristic curve, 0.692; P = .008) for predicting the presence of an estimated GFR of less than 30 mL/min/1.73 m(2). CONCLUSIONS Kidney shear wave speed values obtained by ARFI elastography decrease with the decrease in the estimated GFR.
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Affiliation(s)
- Flaviu Bob
- Departments of Nephrology (F.B., A.S.) and Gastroenterology and Hepatology (S.B., I.S., R.S., A.P.), Victor Babeș University of Medicine and Pharmacy, Timișoara, Romania
| | - Simona Bota
- Departments of Nephrology (F.B., A.S.) and Gastroenterology and Hepatology (S.B., I.S., R.S., A.P.), Victor Babeș University of Medicine and Pharmacy, Timișoara, Romania.
| | - Ioan Sporea
- Departments of Nephrology (F.B., A.S.) and Gastroenterology and Hepatology (S.B., I.S., R.S., A.P.), Victor Babeș University of Medicine and Pharmacy, Timișoara, Romania
| | - Roxana Sirli
- Departments of Nephrology (F.B., A.S.) and Gastroenterology and Hepatology (S.B., I.S., R.S., A.P.), Victor Babeș University of Medicine and Pharmacy, Timișoara, Romania
| | - Alina Popescu
- Departments of Nephrology (F.B., A.S.) and Gastroenterology and Hepatology (S.B., I.S., R.S., A.P.), Victor Babeș University of Medicine and Pharmacy, Timișoara, Romania
| | - Adalbert Schiller
- Departments of Nephrology (F.B., A.S.) and Gastroenterology and Hepatology (S.B., I.S., R.S., A.P.), Victor Babeș University of Medicine and Pharmacy, Timișoara, Romania
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Dudea M, Clichici S, Olteanu DE, Nagy A, Cucoş M, Dudea S. Usefulness of real-time elastography strain ratio in the assessment of bile duct ligation-induced liver injury and the hepatoprotective effect of chitosan: an experimental animal study. ULTRASOUND IN MEDICINE & BIOLOGY 2015; 41:114-123. [PMID: 25438858 DOI: 10.1016/j.ultrasmedbio.2014.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Revised: 07/30/2014] [Accepted: 08/03/2014] [Indexed: 06/04/2023]
Abstract
The purpose of the study described here was to evaluate the usefulness of the elastographic strain ratio in the assessment of liver changes in an experimental animal setting and the hepatoprotective effects of chitosan. Ultrasonography and Strain Ratio calculation were performed before and after bile duct ligation (BDL) in three groups of Wistar albino rats (n = 10 animals per group): (i) rats subjected to bile duct ligation only; (ii) rats subjected to bile duct ligation and administered chitosan for 14 d; (iii) rats subjected to bile duct ligation and administered chitosan for 7 d. The results were compared with the laboratory data and pathologic findings. Strain ratios revealed an increase in liver stiffness after bile duct ligation (p < 0.05), except in the group with chitosan administered for 7 d, and agreed with laboratory and pathology data. In conclusion, strain ratio can be used as an experimental research instrument in the assessment of liver response to injury. To the best of our knowledge, this is the first study reporting on the usefulness of the sonoelastographic liver-to-kidney strain ratio in assessing the effects of experimentally induced liver lesions.
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Affiliation(s)
- Marina Dudea
- Physiology Department, University of Medicine and Pharmacy "Iuliu Haţieganu", Cluj-Napoca, Romania
| | - Simona Clichici
- Physiology Department, University of Medicine and Pharmacy "Iuliu Haţieganu", Cluj-Napoca, Romania.
| | - Diana Elena Olteanu
- Physiology Department, University of Medicine and Pharmacy "Iuliu Haţieganu", Cluj-Napoca, Romania
| | - Andras Nagy
- Pathology Department, Universitatea deŞtiinţe Agricole şi Medicină Veterinară (USAMV), Cluj-Napoca, Romania
| | - Maria Cucoş
- Physiology Department, University of Medicine and Pharmacy "Iuliu Haţieganu", Cluj-Napoca, Romania
| | - Sorin Dudea
- Radiology Department, University of Medicine and Pharmacy "Iuliu Haţieganu", Cluj-Napoca, Romania
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Bob F, Bota S, Sporea I, Sirli R, Petrica L, Schiller A. Kidney shear wave speed values in subjects with and without renal pathology and inter-operator reproducibility of acoustic radiation force impulse elastography (ARFI)--preliminary results. PLoS One 2014; 9:e113761. [PMID: 25426849 PMCID: PMC4245225 DOI: 10.1371/journal.pone.0113761] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Accepted: 10/29/2014] [Indexed: 12/18/2022] Open
Abstract
AIM to assess the inter-operator reproducibility of kidney shear wave speed, evaluated by means of Acoustic Radiation Force Impulse (ARFI) elastography, and the factors which influence it. METHODS Our prospective pilot study included 107 subjects with or without kidney pathology in which kidney shear wave speed was evaluated by means of ARFI elastography. Intraclass correlation coefficient (ICC) was used to assess ARFI elastography reproducibility. RESULTS A strong agreement was obtained between kidney shear wave speed measurements obtained by the two operators: ICC = 0.71 (right kidney) and 0.69 (left kidney). Smaller ICCs were obtained in "healthy subjects", as compared to patients with kidney diseases (0.68 vs. 0.75), in women as compared with men (0.59 vs. 0.78), in subjects younger than 50 years as compared with those aged at least 50 years (0.63 vs. 0.71), in obese as compared with normal weight and overweight subjects (0.36 vs. 0.66 and 0.78) and in case of measurements depth <4 cm or >6 cm as compared with those performed at a depth of 4-6 cm from the skin (0.32 and 0.60 vs. 0.81). CONCLUSION ARFI elastography is a reproducible method for kidney shear wave speed assessment.
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Affiliation(s)
- Flaviu Bob
- Department of Nephrology, “Victor Babes” University of Medicine and Pharmacy, Timişoara, Romania
| | - Simona Bota
- Department of Gastroenterology and Hepatology, “Victor Babes” University of Medicine and Pharmacy, Timişoara, Romania
| | - Ioan Sporea
- Department of Gastroenterology and Hepatology, “Victor Babes” University of Medicine and Pharmacy, Timişoara, Romania
| | - Roxana Sirli
- Department of Gastroenterology and Hepatology, “Victor Babes” University of Medicine and Pharmacy, Timişoara, Romania
| | - Ligia Petrica
- Department of Nephrology, “Victor Babes” University of Medicine and Pharmacy, Timişoara, Romania
| | - Adalbert Schiller
- Department of Nephrology, “Victor Babes” University of Medicine and Pharmacy, Timişoara, Romania
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Orlacchio A, Chegai F, Del Giudice C, Anselmo A, Iaria G, Palmieri G, Di Caprera E, Tosti D, Costanzo E, Tisone G, Simonetti G. Kidney transplant: usefulness of real-time elastography (RTE) in the diagnosis of graft interstitial fibrosis. ULTRASOUND IN MEDICINE & BIOLOGY 2014; 40:2564-72. [PMID: 25218454 DOI: 10.1016/j.ultrasmedbio.2014.06.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 05/11/2014] [Accepted: 06/03/2014] [Indexed: 05/24/2023]
Abstract
The aim of this study is to evaluate the usefulness of real-time elastography (RTE) in the diagnosis of graft interstitial fibrosis. We prospectively enrolled 50 patients clinically suspected of graft fibrosis. RTE was performed with a broadband linear transducer using a dedicated ultrasound machine. Tissue mean elasticity (TME) was calculated by two blinded operators. All patients underwent biopsy after RTE. To determine cortical fibrosis Banff score was used. The receiver operating characteristic curves analysis was performed to evaluate the accuracy of TME to discriminate between patients with mild fibrosis (F1) versus patients with moderate to severe fibrosis (F2-F3). Inverse correlation between TME values and the degree of fibrosis has been shown (p < 0.05). Patients with F1 had mean TME values significantly higher compared with TME in patients with F2 (p = 0.005) and F3 (p = 0.004). The diagnostic accuracy of TME measurement for F2-F3 evaluated by area under the curve-receiver operating characteristic analysis was 0.95. RTE was able to evaluate kidney fibrosis in a non-invasive way and could be used as complementary imaging during follow-up of renal transplant patients.
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Affiliation(s)
- Antonio Orlacchio
- Department of Diagnostic and Molecular Imaging, Radiation Therapy and Interventional Radiology, University Hospital Tor Vergata, Rome, Italy; Organ Transplantation Unit, University Hospital Tor Vergata, Rome, Italy.
| | - Fabrizio Chegai
- Department of Diagnostic and Molecular Imaging, Radiation Therapy and Interventional Radiology, University Hospital Tor Vergata, Rome, Italy
| | - Costantino Del Giudice
- Department of Diagnostic and Molecular Imaging, Radiation Therapy and Interventional Radiology, University Hospital Tor Vergata, Rome, Italy
| | - Alessandro Anselmo
- Organ Transplantation Unit, University Hospital Tor Vergata, Rome, Italy
| | - Giuseppe Iaria
- Organ Transplantation Unit, University Hospital Tor Vergata, Rome, Italy
| | - Giampiero Palmieri
- Institute of Anatomic Pathology, University Hospital Tor Vergata, Rome, Italy
| | - Elena Di Caprera
- Department of Diagnostic and Molecular Imaging, Radiation Therapy and Interventional Radiology, University Hospital Tor Vergata, Rome, Italy
| | - Daniela Tosti
- Department of Diagnostic and Molecular Imaging, Radiation Therapy and Interventional Radiology, University Hospital Tor Vergata, Rome, Italy
| | - Elisa Costanzo
- Department of Diagnostic and Molecular Imaging, Radiation Therapy and Interventional Radiology, University Hospital Tor Vergata, Rome, Italy
| | - Giuseppe Tisone
- Organ Transplantation Unit, University Hospital Tor Vergata, Rome, Italy
| | - Giovanni Simonetti
- Department of Diagnostic and Molecular Imaging, Radiation Therapy and Interventional Radiology, University Hospital Tor Vergata, Rome, Italy
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Gao J, Rubin JM. Ultrasound strain zero-crossing elasticity measurement in assessment of renal allograft cortical hardness: a preliminary observation. ULTRASOUND IN MEDICINE & BIOLOGY 2014; 40:2048-2057. [PMID: 25109692 DOI: 10.1016/j.ultrasmedbio.2014.04.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 03/25/2014] [Accepted: 04/04/2014] [Indexed: 06/03/2023]
Abstract
To determine whether ultrasound strain zero-crossing elasticity measurement can be used to discriminate moderate cortical fibrosis or inflammation in renal allografts, we prospectively assessed cortical hardness with quasi-static ultrasound elastography in 38 renal transplant patients who underwent kidney biopsy from January 2013 to June 2013. With the Banff score criteria for renal cortical fibrosis as gold standard, 38 subjects were divided into two groups: group 1 (n = 18) with ≤25% cortical fibrosis and group 2 (n = 20) with >26% cortical fibrosis. We then divided this population again into group 3 (n = 20) with ≤ 25% inflammation and group 4 (n = 18) with >26% inflammation based on the Banff score for renal parenchyma inflammation. To estimate renal cortical hardness in both population divisions, we propose an ultrasound strain relative zero-crossing elasticity measurement (ZC) method. In this technique, the relative return to baseline, that is zero strain, of strain in the renal cortex is compared with that of strain in reference soft tissue (between the abdominal wall and pelvic muscles). Using the ZC point on the reference strain decompression slope as standard, we determined when cortical strain crossed zero during decompression. ZC was negative when cortical strain did not return or returned after the reference, whereas ZC was positive when cortical strain returned ahead of the reference. Fisher's exact test was used to examine the significance of differences in ZC between groups 1 and 2 and between groups 3 and 4. The accuracy of ZC in determining moderate cortical fibrosis and moderate inflammation was examined by receiver operating characteristic analysis. The intra-class correlation coefficient and analysis of variance were used to test inter-rater reliability and reproducibility. ZC had good inter-observer agreement (ICC = 0.912) and reproducibility (p = 0.979). ZCs were negative in 18 of 18 cases in group 1 and positive in 19 of 20 cases in group 2 (p ≪ 0.001), and were positive in 18 of 20 cases in group 3 and negative in 17 of 18 cases in group 4 (p ≪ 0.001). The area under the receiver operating characteristic curve was 0.992 ± 0.010 for fibrosis and 0.988 ± 0.021 for inflammation. ZC had 100% sensitivity and 95% specificity when zero strain was used as the cutoff value to determine moderate cortical fibrosis and 94% sensitivity and 90% specificity for inflammation. ZC is a new strain marker that could be straightforward to interpret and perform, making it a potentially practical approach for monitoring progression of cortical fibrosis or inflammation in renal allografts.
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Affiliation(s)
- Jing Gao
- Department of Radiology, New York-Presbyterian Hospital, Weill Cornell Medical College, New York, New York, USA.
| | - Jonathan M Rubin
- Department of Radiology, University of Michigan Health System, Ann Arbor, Michigan, USA
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Inci MF, Ozkan F, See TC, Tatli S. Renal Transplant Complications: Diagnostic and Therapeutic Role of Radiology. Can Assoc Radiol J 2014; 65:242-52. [DOI: 10.1016/j.carj.2013.06.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Revised: 06/05/2013] [Accepted: 06/21/2013] [Indexed: 02/08/2023] Open
Abstract
Kidney was the first and is the most frequently transplanted organ. Despite improved surgical techniques and transplantation technology, complications do occur and, if left untreated, may lead to catastrophic consequences. Renal transplantation complications may be vascular (eg, renal artery and vein stenosis and thrombosis, arteriovenous fistula, and pseudoaneurysms); urologic (eg, urinary obstruction and leak, and peritransplantation fluid collections, including hematoma, seroma, lymphocele, and abscess formation); and nephrogenic, including acute tubular necrosis, graft rejection, chronic allograft nephropathy, and neoplasm. Early diagnosis and treatment of these complications are paramount to prevent graft failure and other significant morbidities to the patients. Radiology plays a pivotal role in the diagnosis and treatment of these complications, with minimally invasive percutaneous techniques. In this article, we reviewed renal transplantation anatomy, a wide range of complications that may occur after renal transplantation surgery, typical imaging appearances of the complications on varies imaging modalities, and percutaneous interventional techniques that are used in their treatment.
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Affiliation(s)
- Mehmet Fatih Inci
- Department of Radiology, Sütçü İmam University Medical School, Kahramanmaraş, Turkey
| | - Fuat Ozkan
- Department of Radiology, Sütçü İmam University Medical School, Kahramanmaraş, Turkey
| | - Teik Choon See
- Department of Radiology, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
| | - Servet Tatli
- Division of Abdominal Imaging and Intervention, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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Gao J, Weitzel W, Rubin JM, Hamilton J, Lee J, Dadhania D, Min R. Renal transplant elasticity ultrasound imaging: correlation between normalized strain and renal cortical fibrosis. ULTRASOUND IN MEDICINE & BIOLOGY 2013; 39:1536-1542. [PMID: 23849389 DOI: 10.1016/j.ultrasmedbio.2013.04.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 03/18/2013] [Accepted: 04/11/2013] [Indexed: 05/28/2023]
Abstract
After transplantation, over a widely variable time course, the cortex of the transplanted kidney becomes stiffer as interstitial fibrosis develops and renal function declines. Elasticity ultrasound imaging (EUI) has been used to assess biomechanical properties of tissue that change in hardness as a result of pathologic damage. We prospectively assessed the hardness of the renal cortex in renal transplant allograft patients using a normalized ultrasound strain procedure measuring quasi-static deformation, which was correlated with the grade of renal cortical fibrosis. To determine cortical strain, we used 2-D speckle-tracking software (EchoInsight, Epsilon Imaging, Ann Arbor, MI, USA) to perform offline analysis of stored ultrasound loops capturing deformation of renal cortex and its adjacent soft tissue produced by pressure applied using the scanning transducer. Normalized strain is defined as the mean developed strain in the renal cortex divided by the overall mean strain measured in the soft tissues from the abdominal wall to pelvic muscles. Using the Banff scoring criteria for renal cortical fibrosis as the gold standard, we classified 20 renal transplant allograft biopsy tissue samples into two groups: group 1 (n = 10) with mild (<25%) renal cortical fibrosis and group 2 (n = 10) with moderate (26%-50%) renal cortical fibrosis. An unpaired two-tailed t-test was used to determine the statistical difference in strains between patients with mild and those with moderate renal cortical fibrosis. Receiver operating characteristic curve analysis was performed to assess the accuracy of developed strain and normalized strain in predicting moderate renal cortical fibrosis. The reference strain did not significantly differ between the two groups (p = 0.10). However, the developed renal cortical strain in group 1 with mild fibrosis was higher than that in group 2 with moderate fibrosis (p = 0.025). The normalized strain in group 1 was also higher than that in group 2 (p = 0.0014). The areas under receiver operating characteristic curves for developed strain and normalized strain were 0.78 and 0.95, respectively. The optimal cutoff for distinguishing moderate renal cortical fibrosis was -0.08 for developed strain (sensitivity = 0.50, specificity = 1.0) and 2.5 for normalized strain (sensitivity = 0.80, specificity = 1.0). In summary, renal cortex strain is strongly correlated with grade of renal cortical fibrosis. Normalized strain is superior to developed strain in distinguishing moderate from mild renal cortical fibrosis. We conclude that free-hand real-time strain EUI may be useful in assessing the progression of cortical fibrosis in renal transplant allografts. Further prospective study using this method is warranted.
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Affiliation(s)
- Jing Gao
- Department of Radiology, New York-Presbyterian Hospital, Weill Cornell Medical College, New York, New York 10065, USA.
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