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Vieira IA, Viola GD, Pezzi EH, Kowalski TW, Fernandes BV, Andreis TF, Bom N, Sonnenstrahl G, Rocha YMDA, Corrêa BDS, Donatti LM, Sant’Anna GDS, Corleta HVE, Brum IS, Rosset C, Vianna FSL, Macedo GS, Palmero EI, Ashton-Prolla P. Exploring the frequency of a TP53 polyadenylation signal variant in tumor DNA from patients diagnosed with lung adenocarcinomas, sarcomas and uterine leiomyomas. Genet Mol Biol 2024; 46:e20230133. [PMID: 38252059 PMCID: PMC10802224 DOI: 10.1590/1678-4685-gmb-2023-0133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 11/16/2023] [Indexed: 01/23/2024] Open
Abstract
The TP53 3'UTR variant rs78378222 A>C has been detected in different tumor types as a somatic alteration that reduces p53 expression through modification of polyadenylation and miRNA regulation. Its prevalence is not yet known in all tumors. Herein, we examine tumor tissue prevalence of rs7837822 in Brazilian cohorts of patients from south and southeast regions diagnosed with lung adenocarcinoma (LUAD, n=586), sarcoma (SARC, n=188) and uterine leiomyoma (ULM, n=41). The minor allele (C) was identified in heterozygosity in 6/586 LUAD tumors (prevalence = 1.02 %) and none of the SARC and ULM samples. Additionally, next generation sequencing analysis revealed that all variant-positive tumors (n=4) with sample availability had additional pathogenic or likely pathogenic somatic variants in the TP53 coding regions. Among them, 3/4 (75 %) had the same pathogenic or likely pathogenic sequence variant (allele frequency <0.05 in tumor DNA) namely c.751A>C (p.Ile251Leu). Our results indicate a low somatic prevalence of rs78378222 in LUAD, ULM and SARC tumors from Brazilian patients, which suggests that no further analysis of this variant in the specific studied regions of Brazil is warranted. However, these findings should not exclude tumor molecular testing of this TP53 3'UTR functional variant for different populations.
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Affiliation(s)
- Igor Araujo Vieira
- Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil
- Hospital de Clínicas de Porto Alegre (HCPA), Centro de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil
- Universidade do Vale do Rio dos Sinos (UNISINOS), Escola de Saúde, São Leopoldo, RS, Brazil
| | - Guilherme Danielski Viola
- Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil
- Hospital de Clínicas de Porto Alegre (HCPA), Centro de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil
| | - Eduarda Heidrich Pezzi
- Hospital de Clínicas de Porto Alegre (HCPA), Centro de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil
| | - Thayne Woycinck Kowalski
- Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil
- Hospital de Clínicas de Porto Alegre (HCPA), Centro de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil
- Universidade Federal do Rio Grande do Sul (UFRGS), Laboratório de Genética Médica e Populacional, Porto Alegre, RS, Brazil
- Instituto Nacional de Genética Médica Populacional (INAGEMP), Porto Alegre, RS, Brazil
- Hospital de Clínicas de Porto Alegre (HCPA), Serviço de Genética Médica, Sistema Nacional de Informações sobre Agentes Teratogênicos (SIAT), Porto Alegre, RS, Brazil
- Complexo de Ensino Superior de Cachoeirinha (CESUCA), Cachoeirinha, RS, Brazil
| | - Bruna Vieira Fernandes
- Hospital de Clínicas de Porto Alegre (HCPA), Centro de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil
| | - Tiago Finger Andreis
- Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil
- Hospital de Clínicas de Porto Alegre (HCPA), Centro de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil
| | - Natascha Bom
- Universidade do Vale do Rio dos Sinos (UNISINOS), Curso de Graduação em Biomedicina, São Leopoldo, RS, Brazil
| | - Giulianna Sonnenstrahl
- Universidade do Vale do Rio dos Sinos (UNISINOS), Curso de Graduação em Biomedicina, São Leopoldo, RS, Brazil
| | - Yasminne Marinho de Araújo Rocha
- Hospital de Clínicas de Porto Alegre (HCPA), Centro de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil
| | - Bruno da Silveira Corrêa
- Hospital de Clínicas de Porto Alegre (HCPA), Centro de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil
| | - Luiza Mezzomo Donatti
- Universidade Federal do Rio Grande do Sul, Instituto de Ciências Básicas da Saúde, Departamento de Fisiologia, Laboratório de Biologia Molecular Endócrino e Tumoral, Porto Alegre, RS, Brazil
- Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Porto Alegre, RS, Brazil
| | - Gabriela dos Santos Sant’Anna
- Universidade Federal do Rio Grande do Sul, Instituto de Ciências Básicas da Saúde, Departamento de Fisiologia, Laboratório de Biologia Molecular Endócrino e Tumoral, Porto Alegre, RS, Brazil
| | - Helena von Eye Corleta
- Universidade Federal do Rio Grande do Sul, Instituto de Ciências Básicas da Saúde, Departamento de Fisiologia, Laboratório de Biologia Molecular Endócrino e Tumoral, Porto Alegre, RS, Brazil
- Hospital de Clínicas de Porto Alegre (HCPA), Serviço de Ginecologia e Obstetrícia, Porto Alegre, RS, Brazil
- Universidade Federal do Rio Grande do Sul, Faculdade de Medicina, Departamento de Ginecologia e Obstetrícia, Porto Alegre, RS, Brazil
| | - Ilma Simoni Brum
- Universidade Federal do Rio Grande do Sul, Instituto de Ciências Básicas da Saúde, Departamento de Fisiologia, Laboratório de Biologia Molecular Endócrino e Tumoral, Porto Alegre, RS, Brazil
- Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Porto Alegre, RS, Brazil
| | - Clévia Rosset
- Hospital de Clínicas de Porto Alegre (HCPA), Centro de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil
- Universidade Federal do Rio Grande do Sul (UFRGS), Programa de Pós-Graduação em Ciências Médicas: Medicina (PPGCM), Porto Alegre, RS, Brazil
- Hospital de Clínicas de Porto Alegre (HCPA), Unidade de Pesquisa Laboratorial (UPL), Porto Alegre, RS, Brazil
| | - Fernanda Sales Luiz Vianna
- Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil
- Hospital de Clínicas de Porto Alegre (HCPA), Centro de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil
- Universidade Federal do Rio Grande do Sul (UFRGS), Laboratório de Genética Médica e Populacional, Porto Alegre, RS, Brazil
- Instituto Nacional de Genética Médica Populacional (INAGEMP), Porto Alegre, RS, Brazil
- Hospital de Clínicas de Porto Alegre (HCPA), Serviço de Genética Médica, Sistema Nacional de Informações sobre Agentes Teratogênicos (SIAT), Porto Alegre, RS, Brazil
- Universidade Federal do Rio Grande do Sul (UFRGS), Programa de Pós-Graduação em Ciências Médicas: Medicina (PPGCM), Porto Alegre, RS, Brazil
- Universidade Federal do Rio Grande do Sul, Departamento de Genética, Laboratório de Imunobiologia e Imunogenética, Porto Alegre, RS, Brazil
| | - Gabriel S. Macedo
- Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil
- Hospital de Clínicas de Porto Alegre (HCPA), Centro de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil
- Hospital de Clínicas de Porto Alegre (HCPA), Programa de Medicina Personalizada, Porto Alegre, RS, Brazil
| | - Edenir Inez Palmero
- Instituto Nacional de Câncer (INCA), Departamento de Genética, Rio de Janeiro, RJ, Brazil
- Hospital de Câncer de Barretos, Centro de Pesquisa em Oncologia Molecular, Barretos, SP, Brazil
| | - Patricia Ashton-Prolla
- Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil
- Hospital de Clínicas de Porto Alegre (HCPA), Centro de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil
- Universidade Federal do Rio Grande do Sul (UFRGS), Programa de Pós-Graduação em Ciências Médicas: Medicina (PPGCM), Porto Alegre, RS, Brazil
- Hospital de Clínicas de Porto Alegre (HCPA), Programa de Medicina Personalizada, Porto Alegre, RS, Brazil
- Hospital de Clínicas de Porto Alegre, Serviço de Genética Médica, Porto Alegre, RS, Brazil
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Erbel R, Roth T, Koch L, Ge J, Görge G, Serruys PW, Bom N, Lancée CT, Roelandt J. IVUS of micromotors for cardiovascular imaging. MINIM INVASIV THER 2009. [DOI: 10.3109/13645709709153318] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Flu WJ, van Kuijk JP, Merks EJ, Kuiper R, Verhagen HJ, Bosch JG, Bom N, Bax JJ, Poldermans D. Screening for abdominal aortic aneurysms using a dedicated portable ultrasound system: early results. European Journal of Echocardiography 2009; 10:602-6. [DOI: 10.1093/ejechocard/jep081] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Bom N, Lancée CT, Ligtvoet CM. Improvement of lateral resolution in ultrasonic systems. Acta Med Scand Suppl 2009; 627:41-7. [PMID: 286518 DOI: 10.1111/j.0954-6820.1979.tb01086.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Vidakovic R, Schouten O, Feringa HHH, Dunkelgrun M, Karagiannis SE, Merks E, Bosch J, Bom N, Neskovic AN, Bax JJ, Poldermans D. Abdominal Aortic Aneurysm Screening Using Non-imaging Hand-held Ultrasound Volume Scanner – A Pilot Study. Eur J Vasc Endovasc Surg 2006; 32:615-9. [PMID: 16931068 DOI: 10.1016/j.ejvs.2006.06.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2006] [Accepted: 06/17/2006] [Indexed: 11/18/2022]
Abstract
BACKGROUND Screening for abdominal aortic aneurysms (AAA) is cost-effective and timely repair improves outcome. Using standard ultrasound (US) an AAA can be accurately diagnosed or ruled-out. However, this requires training and bulk equipment. AIM To evaluate the diagnostic potential of a new hand-held ultrasound bladder volume indicator (BVI) in the setting of AAA screening. METHODS In total, 94 patients (66 +/- 14 years, 67 men) referred for atherosclerotic disease were screened for the presence of AAA (diameter > 30 mm using US). All patients underwent both examinations, with US and BVI. Using the BVI, aortic volume was measured at 6 pre-defined points. Maximal diameters (US) and volumes (BVI) were used for analyses. RESULTS In 54 (57%) patients an AAA was diagnosed using US. The aortic diameter by US correlated closely with aortic volume by BVI (r = 0.87, p < 0.0001). Using a cut-off value of > or = 50 ml for the presence of AAA by BVI, sensitivity, specificity, positive and negative predictive value of BVI in detection of AAA were 94%, 82%, 88% and 92%, respectively. The agreement between the two methods was 89%, kappa 0.78. CONCLUSION The bladder volume indicator is a promising tool in screening patients for AAA.
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Affiliation(s)
- R Vidakovic
- Department of Cardiology, Erasmus MC, Rotterdam, The Netherlands
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Palanchon P, van Loon D, Bangma CH, Bom N. Bladder volume measurements with a limited number of fixed ultrasound beams. Ultrasound Med Biol 2004; 30:289-294. [PMID: 15063510 DOI: 10.1016/j.ultrasmedbio.2003.11.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2003] [Revised: 11/10/2003] [Accepted: 11/18/2003] [Indexed: 05/24/2023]
Abstract
Over the past 30 years, various ultrasonic methods have been suggested to measure bladder volume. Ultrasound (US) represents a noninvasive and simple way to assess such volumes. Bladder volumes are usually estimated from cross-sectional planes obtained with instruments using full imaging capabilities, but their accuracy remains limited. This study presents a simple ultrasonic technique that allows the assessment of bladder volume, using only five US beams distributed in a single sagittal plane at predetermined angles. Depending on the number of beams intercepting the bladder, the depth and the height of the bladder could be estimated, and the volume of urine then computed from an empirical formula. To check the validity of the approach, 110 different bladder volume measurements were performed using a 2-D scanning instrument. A total of 33 measurements were used to deduce the empirical formula, which was then used to estimate the volume for the other 77 scans. The computed volumes were compared with calibrated volume data available through voiding or catheterization. A mean error of 9.64% was found, with a relatively constant accuracy for the different volume ranges investigated. Based on this method, a prototype composed of five single-element transducers was developed and tested in clinical situations with 30 patients. The measurements led to a mean error of 70 mL +/- 60 mL with respect to the reference volume. Overall, this study demonstrated the reliability of the proposed method for bladder volume measurements.
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Affiliation(s)
- P Palanchon
- Department of Cardiology, Thoraxcentre, Erasmus MC, Rotterdam, The Netherlands.
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Roelandt JRTC, Bruining N, Bom N. Perspectives in cardiac ultrasound. Przegl Lek 2003; 59:557-61. [PMID: 12638319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Affiliation(s)
- J R T C Roelandt
- Thoraxcentre, Department of Cardiology-H538, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands.
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de Korte CL, Carlier SG, Mastik F, Doyley MM, van der Steen AFW, Serruys PW, Bom N. Morphological and mechanical information of coronary arteries obtained with intravascular elastography; feasibility study in vivo. Eur Heart J 2002; 23:405-13. [PMID: 11846498 DOI: 10.1053/euhj.2001.2806] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
AIMS Plaque composition is a major determinant of coronary related clinical syndromes. In vitro experiments on human coronary and femoral arteries have demonstrated that different plaque types were detectable with intravascular ultrasound elastography. The aim of this study was to investigate the feasibility of applying intravascular elastography during interventional catheterization procedures. METHODS AND RESULTS Data were acquired in patients (n=12) during PTCA procedures with an EndoSonics InVision echoapparatus equipped with radiofrequency output. The systemic pressure was used to strain the tissue, and the strain was determined using cross-correlation analysis of sequential frames. A likelihood function was determined to obtain the frames with minimal motion of the catheter in the lumen, since motion of the catheter prevents reliable strain estimation. Minimal motion was observed near end-diastole. Reproducible strain estimates were obtained within one pressure cycle and over several pressure cycles. Validation of the results was limited to the information provided by the echogram. Strain in calcified material (0.20%+/-0.07) was lower (P<0.001) than in non-calcified tissue (0.51%+/-0.20). CONCLUSION In vivo intravascular elastography is feasible. Significantly higher strain values were found in non-calcified plaques than in calcified plaques.
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Affiliation(s)
- C L de Korte
- Experimental Echocardiography, Thoraxcentre, Erasmus University Rotterdam, The Netherlands
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Doyley MM, Mastik F, de Korte CL, Carlier SG, Céspedes EI, Serruys PW, Bom N, van der Steen AF. Advancing intravascular ultrasonic palpation toward clinical applications. Ultrasound Med Biol 2001; 27:1471-1480. [PMID: 11750745 DOI: 10.1016/s0301-5629(01)00457-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This paper describes the first reported attempt to develop a real-time intravascular ultrasonic palpation system. We also report on our first experience in the catherization laboratory with this new elastographic imaging technique. The prototype system was based on commercially available intravascular ultrasound (US) scanner that was equipped with a 20-MHz array catheter. Digital beam-formed radiofrequency (RF) echo data (i.e., 12 bits, 100 Hz) was captured at full frame rate from the scanner and transferred to personal computer (PC) memory using a fast data-acquisition system. Composite palpograms were created by applying a one-dimensional (1-D) echo tracking technique in combination with global motion compensation and multiframe averaging to several pairs of RF echo frames that were obtained in the diastolic phase of the cardiac cycle. The quality of palpograms was assessed by conducting experiments on vessel phantoms and on patients. The results demonstrated that robust and consistent palpograms could be generated in almost real-time using the proposed system. Good correlation was observed between low strain values and regions of calcification as identified from the intravascular US (IVUS) sonograms. Although the clinical results are clearly preliminary, it was concluded that the prototype system performed sufficiently well to warrant further and more in-depth clinical investigation.
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Affiliation(s)
- M M Doyley
- Thoraxcentre, Erasmus University, Rotterdam 3000 DR The Netherlands
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Palanchon P, Bouakaz A, van Blankenstein JH, Klein J, Bom N, de Jong N. New technique for emboli detection and discrimination based on nonlinear characteristics of gas bubbles. Ultrasound Med Biol 2001; 27:801-808. [PMID: 11516540 DOI: 10.1016/s0301-5629(01)00384-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Detection and characterization of emboli in the blood stream is of high clinical importance for making decisions after surgery. In this study, a new technique based on the nonlinear oscillations of gas bubbles was applied to gaseous emboli detection, characterization and sizing. To simulate gaseous emboli, an experimental system was developed to produce air bubbles of uniform diameters ranging from 19 microm up to 200 microm. The ultrasonic setup consisted of low-frequency transducers operating at 130 kHz and 250 kHz and using low acoustic pressures (30 kPa and 55 kPa). The experimental and theoretical results show that, depending on the transmitted frequency and the bubble sizes, higher harmonic components were produced in the frequency spectrum of the backscattered echo. Nonresonating bubbles scatter either linearly when their sizes are far away from the resonance size or nonlinearly at the second or third harmonic frequency when their sizes are getting close to the resonance size. Only resonant bubbles or bubbles very close to the resonance size are able to scatter at higher harmonic frequencies (fourth and fifth). This property is used to discriminate resonating bubbles from other bubble sizes. The appearance of harmonic component in the frequency spectrum seems to be an unambiguous tool to differentiate gaseous emboli from solid emboli that scatter linearly.
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Affiliation(s)
- P Palanchon
- Department of Cardiology, Thoraxcentre, Erasmus Medical Centre Rotterdam, Rotterdam, The Netherlands.
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Schuurbiers JC, von Birgelen C, Wentzel JJ, Bom N, Serruys PW, de Feyter PJ, Slager CJ. On the IVUS plaque volume error in coronary arteries when neglecting curvature. Ultrasound Med Biol 2000; 26:1403-1411. [PMID: 11179614 DOI: 10.1016/s0301-5629(00)00295-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Plaque volume determined by common linear 3-D IVUS analysis systems will show under- or overestimation in curved vessel segments because these systems approximate the true 3-D transducer pull-back trajectory by a straight line. We developed a mathematical model that showed that the error is primarily dependent on the curvature of the pull-back trajectory and not on vessel tortuosity. Furthermore, we measured this error in vivo in the coronary arteries of 15 patients, comparing the plaque volume using a true 3-D reconstruction method with that of the linear approach. The in vivo plaque volume error ranged from 2.3% to -1.2% for 15 coronary segments with lengths ranging from 38.8 to 89.1 mm (62.2 +/- 13 mm). The volume error introduced by linear 3-D IVUS analysis systems is dependent on the curvature of the pull-back trajectory. The error measured in vivo was small and inversely related to segment length.
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Affiliation(s)
- J C Schuurbiers
- Department of Cardiology, Thoraxcenter, University Hospital Rotterdam-Dijkzigt, Rotterdam, The Netherlands.
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Hagenaars T, Gussenhoven EJ, van Sambeek MR, Jukema JW, Kranendonk SE, Bom N. Effect of simvastatin on restenosis after percutaneous transluminal angioplasty of femoropopliteal arterial obstruction. Am J Cardiol 2000; 86:774-6, A6. [PMID: 11018199 DOI: 10.1016/s0002-9149(00)01079-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This retrospective observational intravascular ultrasound study evaluated whether simvastatin therapy limits lumen area reduction 1-year after percutaneous transluminal angioplasty (PTA) by reducing reactive plaque growth, reducing reactive vasoconstriction, or both. This study showed that plaque growth is a general response 1 year after PTA regardless of the use of simvastatin; simvastatin has the potential to induce positive vascular remodeling, thereby reducing the occurrence of restenosis.
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Affiliation(s)
- T Hagenaars
- Department of Cardiology, Erasmus Medical Center, Rotterdam, The Netherlands.
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Abstract
The heart is a three-dimensional (3-D) object and, with the help of 3-D echocardiography (3-DE), it can be shown in a realistic fashion. This capability decreases variability in the interpretation of complex pathology among investigators. Therefore, it is likely that the method will become the standard echocardiography examination in the future. The availability of volumetric data sets allows retrieval of an infinite number of cardiac cross-sections. This results in more accurate and reproducible measurements of valve areas, cardiac mass and cavity volumes by obviating geometric assumptions. Typical 3-DE parameters, such as ejection fraction, flow jets, myocardial perfusion and LV wall curvature, may become important diagnostic parameters based on 3-DE. However, the freedom of an infinite number of cross-sections of the heart can result in an often-encountered problem of being "lost in space" when an observer works on a 3-DE image data set. Virtual reality computing techniques in the form of a virtual heart model can be useful by providing spatial "cardiac" information. With the recent introduction of relatively low cost portable echo devices, it is envisaged that use of diagnostic ultrasound (US) will be further boosted. This, in turn, will require further teaching facilities. Coupling of a cardiac model with true 3-D echo data in a virtual reality setting may be the answer.
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Affiliation(s)
- N Bruining
- Thoraxcentre, Department of Cardiology, Erasmus Medical Centre Rotterdam, Erasmus University, Rotterdam, The Netherlands.
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Hagenaars T, Gussenhoven EJ, van der Linden E, Bom N. Reproducibility of calcified lesion quantification: a longitudinal intravascular ultrasound study. Ultrasound Med Biol 2000; 26:1075-1079. [PMID: 11053741 DOI: 10.1016/s0301-5629(00)00246-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In view of a prospective intravascular ultrasound (IVUS) study, the reproducibility of the extent of the calcified lesion in IVUS images derived from separate pull-back maneuvers was assessed. Patients (n = 34) were imaged with IVUS before and after percutaneous transluminal angioplasty (PTA) and at 1-y follow-up. In the presence of a calcified lesion, the largest arc and the length of the matched calcified lesions was assessed. Interobserver differences in arc measurements were low (< or = 0.7%), with low coefficients of variation (< or = 5.8%). Similarly, interexamination differences in arc and length measurements were small (< or = 1.1%), with low coefficients of variation (< or = 3.2%). At follow-up, a nonsignificant increase in both the arc (1.9%) and length (1.7%) of the calcified lesion was observed. This study showed that measurements of the calcified lesion are highly reproducible; changes seen at 1-y follow-up were not significant. We conclude that IVUS may be used to monitor the effect of medical intervention on the extent of the calcified lesion in a longitudinal study.
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Affiliation(s)
- T Hagenaars
- Department of Cardiology, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
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de Korte CL, Pasterkamp G, van der Steen AF, Woutman HA, Bom N. Characterization of plaque components with intravascular ultrasound elastography in human femoral and coronary arteries in vitro. Circulation 2000; 102:617-23. [PMID: 10931800 DOI: 10.1161/01.cir.102.6.617] [Citation(s) in RCA: 216] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The composition of plaque is a major determinant of coronary-related clinical syndromes. Intravascular ultrasound (IVUS) elastography has proven to be a technique capable of reflecting the mechanical properties of phantom material and the femoral arterial wall. The aim of this study was to investigate the capability of intravascular elastography to characterize different plaque components. METHODS AND RESULTS Diseased human femoral (n=9) and coronary (n=4) arteries were studied in vitro. At each location (n=45), 2 IVUS images were acquired at different intraluminal pressures (80 and 100 mm Hg). With the use of cross-correlation analysis on the high-frequency (radiofrequency) ultrasound signal, the local strain in the tissue was determined. The strain was color-coded and plotted as an additional image to the IVUS echogram. The visualized segments were stained on the presence of collagen, smooth muscle cells, and macrophages. Matching of elastographic data and histology were performed with the use of the IVUS echogram. The cross sections were segmented in regions (n=125) that were based on the strain value on the elastogram. The dominant plaque types in these regions (fibrous, fibro-fatty, or fatty) were obtained from histology and correlated with the average strain and echo intensity. The strain for the 3 plaque types as determined by histology differed significantly (P=0.0002). This difference was mainly evident between fibrous and fatty tissue (P=0.0004). The plaque types did not reveal echo-intensity differences in the IVUS echogram (P=0.882). CONCLUSIONS Different strain values are found between fibrous, fibro-fatty, and fatty plaque components, indicating the potential of intravascular elastography to distinguish different plaque morphologies.
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Affiliation(s)
- C L de Korte
- Experimental Echocardiography, Thoraxcentre, Rotterdam, The Netherlands.
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16
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Bom N, van der Steen AF, Nosir YF, Kasprzak JD. Studies of cardiac function and myocardial tissue characterization. Proc Inst Mech Eng H 2000; 214:141-9. [PMID: 10825772 DOI: 10.1243/0954411001535318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The heart can be studied using ultrasound techniques. The shape of the heart, its chambers, wall thicknesses, wall tissue characteristics as well as motion of walls and valve leaflets are all diagnostic information. In addition, the blood velocity and its timing within the cardiac cycle is an important diagnostic tool. In the present paper focus will be limited to the analysis of the left ventricular function as observed with two-dimensional and three-dimensional echocardiography and the characteristics of backscattered ultrasound information from the left ventricular chamber wall. Function of the heart is often studied by observation of local wall motion or comparison of chamber volume in maximum and minimum shapes during the cardiac cycle (ejection fraction). Integrated backscatter from the wall is described in examples of cardiac transplantation and hypertrophy. Study of cyclic variation of frequency-dependent attenuation and integrated backscatter indicates that these are independent parameters.
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Affiliation(s)
- N Bom
- Thoraxcentre, Erasmus University Rotterdam, The Netherlands
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17
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Djoa KK, de Jong N, van Egmond FC, Kasprzak JD, Vletter WB, Lancée CT, van der Steen AF, Bom N, Roelandt JR. A fast rotating scanning unit for real-time three-dimensional echo data acquisition. Ultrasound Med Biol 2000; 26:863-869. [PMID: 10942833 DOI: 10.1016/s0301-5629(00)00201-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Most three-dimensional (3-D) echocardiography (3-DE) systems today are based on off-line methods where a large number of cross-sectional 2-D scans have to be acquired sequentially before a 3-D image can be reconstructed. Because acquisition is done step-by-step based on ECG triggering plus respiratory gating, this introduces motion artefacts and takes significant acquisition time. Another 3-D approach is based on 2-D transducers and parallel beam-forming. Such a system is very complex. In this manuscript, a fast continuously-rotating scanning unit, based on a 64-element phased-array transducer, is described. Typical rotation speed of the 3-D unit is 8 rotations per s. Therefore, 16 3-D volume datasets can be acquired per s in real-time. The first clinical examples as acquired with this probe are presented.
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Affiliation(s)
- K K Djoa
- Thoraxcentre Laboratory for Experimental Echocardiography, Erasmus University Rotterdam, Rotterdam, The Netherlands
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18
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de Korte CL, van der Steen AF, Cépedes EI, Pasterkamp G, Carlier SG, Mastik F, Schoneveld AH, Serruys PW, Bom N. Characterization of plaque components and vulnerability with intravascular ultrasound elastography. Phys Med Biol 2000; 45:1465-75. [PMID: 10870704 DOI: 10.1088/0031-9155/45/6/305] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Intravascular ultrasound elastography is a method for measuring the local elastic properties using intravascular ultrasound (IVUS). The elastic properties of the different tissues within the atherosclerotic plaque are measured through the strain. Knowledge of these elastic properties is useful for guiding interventional procedures (balloon dilatation, ablation) and detection of the vulnerable plaque. In the last decade, several groups have applied elastography intravascularly with various levels of success. In this paper, the approaches of the different research groups will be discussed. The focus will be on our approach to the application of intravascular elastography. Elastograms were acquired in vitro and in vivo using the relative local displacements between IVUS images acquired at two levels of intravascular pressure with a 30 MHz mechanical or a 20 MHz array echo catheter. These displacements were estimated from the time shift between gated radiofrequency echo signals using cross-correlation algorithms with interpolation around the peak. Experiments on gel-based phantoms mimicking atherosclerotic vessels demonstrated the capability of elastography to identify soft and hard tissues independently of the echogenicity contrast. In vitro experiments on human arteries have demonstrated the potential of intravascular elastography to identify different plaque types based on their mechanical properties. These plaques could not be identified using the IVUS image alone. In vivo experiments revealed that reproducible elastograms could be obtained near end-diastole. Partial validation using the echogram was performed. Intravascular elastography provides information that is frequently unavailable or inconclusive from the IVUS image and which may therefore assist in the diagnosis and treatment of atherosclerotic disease.
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19
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Bom N, de Korte CL, Wentzel JJ, Krams R, Carlier SG, van der Steen AW, Slager CJ, Roelandt JR. Quantification of plaque volume, shear stress on the endothelium, and mechanical properties of the arterial wall with intravascular ultrasound imaging. Z Kardiol 2000; 89 Suppl 2:105-11. [PMID: 10769412 DOI: 10.1007/s003920070108] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Present intravascular echographic imaging (IVUS) is based on either the mechanically rotated single element catheter or the multi-element phased array catheter principle. In both methods the ultrasonic beam is rotated through 360 degrees and the cross-sectional echo image of plaque and wall structures is visualised. A new development based on intravascular ultrasound is calculation of mechanical properties of the arterial wall. In this so-called elastographic approach, high frequency information obtained at identical positions in the arterial wall is compared under systolic and diastolic pressures. Minute shifts in the echo data indicate local compressibility. It thus becomes possible to indicate areas of high or low strain, which correspond to soft and hard material. Three-dimensional information can be obtained if the position of cross sectional slices is recorded with a pull-back device and slices are united into a 3D image. On the basis of such information it has become possible to view stents in 3D, and with interactive software, to calculate automatically plaque volume. With pull-back information only, the artery is reconstructed as a "straight pipe". Only when the biplane X-ray information is combined with the intravascular pull-back echo information can the true 3D reconstruction of the artery be constructed. Given the true geometric lumen information, it becomes possible, under certain assumptions, to derive the luminal fluid dynamics. From this, shear stress values close to the arterial wall can be calculated. Under the assumption that low values for local shear stress are areas prone to restenosis, predictions of endangered areas can be made.
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Affiliation(s)
- N Bom
- Erasmus University Rotterdam, The Netherlands.
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20
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Affiliation(s)
- N Bom
- Thoraxcentre, Erasmus University Rotterdam, Rotterdam, The Netherlands
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21
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van der Steen AF, Céspedes EI, Carlier SG, Mastik F, Lupotti F, Borsboom JM, Li W, Serruys PW, Bom N. Flow estimation using an intravascular imaging catheter. Ultrasonics 2000; 38:363-368. [PMID: 10829689 DOI: 10.1016/s0041-624x(99)00213-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Coronary flow assessment can be useful for determining the hemodynamic severity of a stenosis and to evaluate the outcome of interventional therapy. We developed a method for measuring the transverse flow through the imaging plane of an intravascular ultrasound (IVUS) catheter. This possibility has raised great clinical interest since it permits simultaneous assessment of vessel geometry and function with the same device. Furthermore, it should give more accurate information than combination devices because lumen diameter and velocity are determined at the same location. Flow velocity is estimated based on decorrelation estimation from sequences of radiofrequency (RF) traces acquired at nearly the same position. Signal gating yields a local estimate of the velocity. Integrating the local velocity over the lumen gives the quantitative flow. This principle has been calibrated and tested through computer modeling, in vitro experiments using a flow phantom and in vivo experiments in a porcine animal model, and validated against a Doppler element containing guide wire (Flowire) in humans. Originally the method was developed and tested for a rotating single element device. Currently the method is being developed for an array system. The great advantage of an array over the single element approach would be that the transducer has no intrinsic motion. This intrinsic motion sets a minimal threshold in the detectable velocity components. Although the principle is the same, the method needs some adaptation through the inherent different beamforming of the transducer. In this paper various aspects of the development of IVUS flow are reviewed.
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22
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Bouakaz A, Frinking PJ, de Jong N, Bom N. Noninvasive measurement of the hydrostatic pressure in a fluid-filled cavity based on the disappearance time of micrometer-sized free gas bubbles. Ultrasound Med Biol 1999; 25:1407-15. [PMID: 10626628 DOI: 10.1016/s0301-5629(99)00109-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
A new method for noninvasive pressure measurement, based on the disappearance time of micrometer-sized free gas bubbles, is described in this article. An ultrasound (US) contrast agent, consisting of encapsulated gas bubbles, is used as a vehicle to transport the free gas bubbles to the desired region where the pressure is to be measured. The small free gas bubbles are generated at the region of interest (e.g., heart chambers), from the encapsulated gas bubbles, which rupture when they are exposed to a single low-frequency (e.g., 0.5 MHz), high acoustic amplitude US burst. The released gas bubbles persist for only a few ms and dissolve in the liquid, depending on their size, the gas, the liquid characteristics and ambient parameters such as temperature, gas concentration and pressure. A pressure-disappearance time relationship is determined using a sequence of high-frequency (e.g., 10 MHz), low acoustic amplitude US pulses. From in vitro experiments, reproducible results show a significant difference between the disappearance time of the bubbles as function of the local pressure, resulting in a quicker disappearance of the bubble for higher values of the pressure. The sensitivity of the method to small pressure changes (50 mmHg) is demonstrated.
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Affiliation(s)
- A Bouakaz
- Department of Cardiology and Experimental Echocardiography, Thoraxcenter, Erasmus University Rotterdam, The Netherlands.
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23
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Leertouwer TC, Gussenhoven EJ, van Jaarsveld BC, van Overhagen H, Bom N, Man in 't Veld AJ. In-vitro validation, with histology, of intravascular ultrasound in renal arteries. J Hypertens 1999; 17:271-7. [PMID: 10067797 DOI: 10.1097/00004872-199917020-00012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To investigate the feasibility of using intravascular ultrasound to characterize normal and diseased renal arteries. MATERIALS AND METHODS Forty-four renal artery specimens from 21 humans, removed at autopsy, were studied with intravascular ultrasound in vitro. From each vascular specimen, two to four sets of corresponding intravascular ultrasound images and histologic sections were subjected to qualitative analysis. The renal arterial wall was considered normal by intravascular ultrasound when the wall thickness (intima and media) was 0.5 mm or less. On intravascular ultrasound imaging, a distinction was made between bright lesions with or without peripheral shadowing (i.e. calcification). Histological sections were examined and fibromuscular lesions were scored with or without calcifications. Quantitative analysis of a multitude of intravascular ultrasound cross-sections (interval 5 mm) included assessment of the lumen area, vessel area, plaque area and percentage area obstructed. The target site (smallest lumen area) was compared with a reference site (largest lumen area before the first major side branch). RESULTS Of the 130 corresponding intravascular ultrasound images and histologic sections analysed, 55 were normal and 75 presented a bright lesion on ultrasound; in 31 lesions, peripheral shadowing was involved. The sensitivity of the intravascular ultrasound in detecting calcifications was 87%, and the specificity was 89%. Lumen area reduction at the target site was associated with vessel and plaque area enlargement in eight specimens, with plaque area enlargement in 12 specimens and with a vessel area reduction in 21 specimens. CONCLUSIONS Intravascular ultrasound is a reliable technique for distinguishing renal arteries with or without a lesion. Both plaque development and local vessel narrowing may result in renal artery stenosis.
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Affiliation(s)
- T C Leertouwer
- Department of Internal Medicine, University Hospital Rotterdam-Dijkzigt and Erasmus University Rotterdam, The Netherlands
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24
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Shiota T, Lewandowski R, Piel JE, Smith LS, Lancée C, Djoa K, Bom N, Cobanoglu A, Rice MJ, Sahn DJ. Micromultiplane transesophageal echocardiographic probe for intraoperative study of congenital heart disease repair in neonates, infants, children, and adults. Am J Cardiol 1999; 83:292-5, A7. [PMID: 10073843 DOI: 10.1016/s0002-9149(98)00845-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This study reports the development of a micromultiplane 8.2-mm transesophageal echocardiographic probe. The probe is applicable to newborn infants and can deliver diagnostic images in adults.
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Affiliation(s)
- T Shiota
- The Clinical Care Center for Congenital Heart Disease, Oregon Health Sciences University, Portland 97201, USA
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25
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de Korte CL, Cespedes EI, van der Steen AF, Pasterkamp G, Bom N. Intravascular ultrasound elastography: assessment and imaging of elastic properties of diseased arteries and vulnerable plaque. Eur J Ultrasound 1998; 7:219-24. [PMID: 9700219 DOI: 10.1016/s0929-8266(98)00043-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVE Intravascular elastography is concerned with methods for measuring the local elastic properties using intravascular ultrasound (IVUS). The elastic properties of the vessel wall and atheroma can be measured through the strain. Knowledge of these mechanical properties is useful for guiding interventional procedures (balloon dilatation, ablation) and detection of plaque vulnerability. METHODS Elastograms and palpograms (images of strain) were constructed using the relative local displacements between IVUS images acquired at two levels of intravascular pressure with a 30-MHz echo catheter. These displacements were estimated from the time shift between gated radio-frequency echo signals using cross-correlation algorithms with interpolation around the peak. RESULTS Experiments on gel-based phantoms mimicking atherosclerotic vessels demonstrated the capability of elastography to identify soft and hard plaques independently of the echogenicity contrast. In vitro experiments on human arteries have demonstrated the potential of intravascular elastography to identify different plaque types based on the mechanical properties. These plaques could not be identified using the IVUS image alone. Regions with elevated mechanical stress could also be detected. These stress concentrations are related to plaque fracture. CONCLUSION Intravascular elastography provides information that is frequently unavailable or inconclusive from the IVUS image and therefore may assist in the diagnosis and treatment of atherosclerotic disease.
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Affiliation(s)
- C L de Korte
- Exp. Echo Ee 23.02, Erasmus University, PO Box 1738, 3000 DR Rotterdam, The Netherlands.
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26
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de Groot E, Zwinderman AH, van der Steen AF, Ackerstaff RG, Montauban van Swijndregt AD, Bom N, Lie KI, Bruschke AV. Variance components analysis of carotid and femoral intima-media thickness measurements. REGRESS Study Group, Interuniversity Cardiology Institute of The Netherlands, Utrecht, The Netherlands. Regression Growth Evaluation Statin Study. Ultrasound Med Biol 1998; 24:825-832. [PMID: 9740384 DOI: 10.1016/s0301-5629(98)00037-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
B-mode ultrasound intima-media thickness (IMT) measurements of carotid and femoral arterial walls are used in atherosclerosis studies. In this study, the components contributing to IMT measurement variability in males with coronary artery disease were investigated by means of repeated B-mode ultrasound scans and repeated off-line video image analyses. For statistical analysis, a mixed-model analysis of variance was used. From sonographer data, it was shown that human subjects and their arterial wall segments contributed 75% of the total IMT measurement variability in this population. Inter-sonographer variance contributed 25%. The intra-sonographer variance was negligible (<1%). In off-line image analysis, variance components due to subjects and segments, inter-analyst variance, and residual fluctuation were 88%, < 1% and 11%, respectively. Intra-analyst variance was negligible (<1%). The major source of B-mode ultrasound IMT measurement variability finds its origin in subjects and their arterial walls. Although sonographers proved a lesser source of variability, in comparative studies they should enter a study well trained and should be randomly assigned to subjects. Follow-up examinations should preferably be done by the same sonographer. Off-line image analysis contributed little to IMT measurement variability.
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Affiliation(s)
- E de Groot
- Interuniversity Cardiology Institute of The Netherlands, Utrecht
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27
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Carlier SG, Li W, Céspedes I, van der Steen AF, Hamburger JN, Bom N, Serruys PW. Images in cardiovascular medicine. Simultaneous morphological and functional assessment of a renal artery stent intervention with intravascular ultrasound. Circulation 1998; 97:2575-6. [PMID: 9657479 DOI: 10.1161/01.cir.97.25.2575] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- S G Carlier
- Thoraxcentre Erasmus University Rotterdam, The Netherlands.
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28
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de Groot E, Jukema JW, Montauban van Swijndregt AD, Zwinderman AH, Ackerstaff RG, van der Steen AF, Bom N, Lie KI, Bruschke AV. B-mode ultrasound assessment of pravastatin treatment effect on carotid and femoral artery walls and its correlations with coronary arteriographic findings: a report of the Regression Growth Evaluation Statin Study (REGRESS). J Am Coll Cardiol 1998; 31:1561-7. [PMID: 9626835 DOI: 10.1016/s0735-1097(98)00170-3] [Citation(s) in RCA: 184] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVES In this B-mode ultrasound study we assessed pravastatin treatment effects on carotid and femoral artery walls and investigated the correlations between the state and evolution of peripheral and coronary atherosclerosis. BACKGROUND The Regression Growth Evaluation Statin Study (REGRESS) was an 11-center, 2-year, double-blind, placebo-controlled, prospective study of 885 men with coronary artery disease (CAD) (total cholesterol 4 to 8 mmol/liter). The study primarily investigated pravastatin treatment effects on the coronary lumen. This report focuses on the 255 patients who participated in the REGRESS ultrasound study. METHODS Carotid and femoral artery walls were imaged at baseline and at 6, 12, 18 and 24 months. Pravastatin treatment effect was defined as the difference in progression of the combined intima-media thicknesses (IMT) between treatment groups. RESULTS Pravastatin treatment effects were highly significant (combined IMT: p = 0.0085; combined far wall IMT: p < 0.0001; common femoral artery far wall IMT: p = 0.004). Correlations between the IMTs of the arterial wall segments ranged from -0.17 to 0.81. Baseline correlations between IMT and percent coronary lumen stenoses ranged from 0.23 to 0.36. Baseline IMT correlated with the mean coronary segment diameter (r = -0.32, p = 0.001) and minimal coronary obstruction diameter (r = -0.27, p = 0.005). There were no individual correlations between IMT and coronary lumen variables (p > 0.30). CONCLUSIONS Pravastatin treatment effects on carotid and femoral artery walls were observed. B-mode ultrasound imaging studies of peripheral arterial walls could not describe the state and evolution of the coronary lumen in the individual patient, but proved to be a highly suitable tool for the assessment of antiatherosclerotic properties of agents.
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Affiliation(s)
- E de Groot
- Interuniversity Cardiology Institute, Utrecht, The Netherlands
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29
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Carlier SG, Cespedes EI, Li W, Mastik F, Van Der Steen AF, Bom N, Serruys PW. Blood flow assessment with intravascular ultrasound catheters: the ideal tool for simultaneous assessment of the coronary haemodynamics and vessel wall? Semin Interv Cardiol 1998; 3:21-9. [PMID: 10094181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
We present the potentials of a novel method of intracoronary flow visualization and quantification that is based on conventional intravascular ultrasound (IVUS) imaging catheters. The quantification of flow is obtained from analysis of the rate of decorrelation of digitized radiofrequency ultrasound echo signals. Flow information is superimposed on the IVUS image using a colour scale. Integration of the blood velocity components normal to the scan plane permits calculation of the volume flow. Validation using IVUS and electromagnetic (EM) flowmeter recordings were obtained in vivo from instrumented pigs. IVUS flow (IVUS(f)) compared favourably to EM flow (EM(f)): IVUS(f)=1.0 EM(f)+5.72 cc/min, r2=0.98. Clinical results for the first five patients investigated are reported. A Doppler wire was used to measure the flow in four coronary arteries and one renal artery in baseline and hyperaemia conditions. IVUS flow and derived coronary flow reserve (CFR) demonstrated a very good agreement with the data derived from the combination of quantitative angiography and velocity when measured with the Doppler wire (DOP(f)): IVUS(f)=1.01 DOP(f)-20 cc/min, r2=0.90 and IVUS(cfr)=1.03 DOP(cfr)-0.03, r2=0.93. This demonstrates that simultaneous morphological and physiological assessment of coronary or peripheral arteries with one IVUS catheter is feasible. This method should be very useful for the evaluation of intermediate coronary stenoses or the results of revascularization procedures.
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Affiliation(s)
- S G Carlier
- Erasmus University Rotterdam, Thoraxcentre, The Netherlands
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30
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Abstract
Based on three-dimensional (3D) information, quantitative data such as plaque volume can be calculated. The procedure includes automatic contour detection based in image segmentation methods and greatly speeds up clinical evaluation. With the use of additional X-ray information, the true tortuous vessel geometry can be reconstructed in 3D. This allows, by numerical modelling techniques, to calculate endothelial shear stress values which in turn may indicate sites prone to stenosis. With a decorrelation technique for radio frequency (RF) echo information from sequential data in the same beam direction and integration method over the entire cross section, blood velocity can be shown colour-coded during the cardiac cycle, while even blood flow quantification seems to be possible. In vitro as well as animal experiments have shown the feasibility of the method. Intravascular imaging can be used to study the biomechanical properties of atheroma components. Local radial strain as a measure of local tissue hardness can be estimated in principle. Hard or soft plaques can be identified from the strain images independently of the echogenic contrast between plaque and vessel wall.
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Affiliation(s)
- N Bom
- Thoraxcentre, Erasmus University Rotterdam, The Netherlands.
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31
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Abstract
IntraVascular Ultrasound Imaging (IVUS) has already been proposed in the early days of diagnostic ultrasound. Today, it has come under further full attention as a result of minimal invasive techniques. Not only excellent intravascular two-dimensional (2D) images are presently obtained, also three-dimensional (3D) reconstructed images show their diagnostic value. Based on 3D information, quantitative data such as plaque volume can be calculated. The procedure includes automatic contour detection based on image segmentation methods and greatly speeds up clinical evaluation. With the use of additional X-ray information, the true tortuous vessel geometry can be reconstructed in 3D. This allows, by numerical modelling techniques, to calculate endothelial shear stress values, which in turn may indicate sites prone to stenosis. With a decorrelation technique for radiofrequency (RF) echo information from sequential data in the same beam direction and integration method over the entire cross section, blood velocity can be shown colour-coded during the cardiac cycle, while even blood flow quantification seems to be possible. In vitro as well as in vivo experiments have shown the feasibility of the method. Intravascular imaging can be used to study the biomechanical properties of atheroma components. Local radial strain, used as a measure of local tissue hardness, can be estimated to identify hard or soft plaques independently of the echogenicity contrast between plaque and vessel wall.
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Affiliation(s)
- N Bom
- Thoraxcentre Ee 2302, Erasmus University Rotterdam and University Hospital Rotterdam-Dijkzigt, P.O. Box 1738, 3000 DR Rotterdam, The Netherlands.
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32
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Li W, van der Steen AF, Lancée CT, Céspedes I, Bom N. Blood flow imaging and volume flow quantitation with intravascular ultrasound. Ultrasound Med Biol 1998; 24:203-14. [PMID: 9550179 DOI: 10.1016/s0301-5629(97)00275-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Current intravascular ultrasound techniques produce real-time imaging of a vessel cross-section with a scan plane approximately normal to blood flow. When a cluster of randomly distributed blood particles moves across the ultrasound beam, the received echo signals decorrelate as a function of time. This phenomenon may be used to estimate blood velocities by measuring the decorrelation rate from a sequence of blood scattering signals. A decorrelation-based method for measuring local blood velocity and quantifying volume flow from cross-sectional radio frequency intravascular echo signals was developed. Serial in vitro measurements were performed with a flow phantom to test the principle of the proposed velocity estimation method. An in vivo pig experiment was carried out to study the feasibility of applying this method in clinical settings. Preliminary results of this study indicate that the proposed decorrelation method is able to extract cross-sectional velocity data and volumetric flow both in vitro and in vivo.
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Affiliation(s)
- W Li
- Thoraxcentre, Erasmus University Rotterdam, The Netherlands
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Li W, Lancée CT, Céspedes EI, van der Steen AF, Bom N. Decorrelation of intravascular echo signals: potentials for blood velocity estimation. J Acoust Soc Am 1997; 102:3785-3794. [PMID: 9407670 DOI: 10.1121/1.420141] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
When blood particles travel through an intravascular ultrasound imaging plane, the received echo signals decorrelate at a rate that is related to the flow velocity. In this paper, the feasibility of extracting blood velocity from the decorrelation function of radio frequency signals was investigated through theoretical analysis and computer simulation. A computer model based on the impulse response method was developed to generate the ultrasound field of a 30-MHz intravascular transducer. The decorrelation due to the scatterer displacement as well as other nonmotion related decorrelation sources were studied. The computer simulations show that the decorrelation function is linearly related to the lateral displacement. The monotonic relationship between correlation and displacement provides possibilities to estimate flow velocity with decorrelation measurements. Because of the complexity of the beam profile in the near field, assessment of local velocities requires detailed knowledge of the decorrelation at each axial beam position. Sources of signal decorrelation other than the lateral displacement may cause a bias in the decorrelation based velocity measurements. For localized decorrelation estimation, measurement variations in small range windows present a major challenge. An approach based on multiple decorrelation measurements should be adopted in order to reduce the variations. In conclusion, results of this study suggest that it is feasible to measure flow velocity by quantifying the decorrelation of intravascular ultrasound signals from blood.
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Affiliation(s)
- W Li
- Thoraxcentre, Erasmus University Rotterdam, The Netherlands.
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34
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Peters RJ, Kok WE, Di Mario C, Serruys PW, Bär FW, Pasterkamp G, Borst C, Kamp O, Bronzwaer JG, Visser CA, Piek JJ, Panday RN, Jaarsma W, Savalle L, Bom N. Prediction of restenosis after coronary balloon angioplasty. Results of PICTURE (Post-IntraCoronary Treatment Ultrasound Result Evaluation), a prospective multicenter intracoronary ultrasound imaging study. Circulation 1997; 95:2254-61. [PMID: 9142002 DOI: 10.1161/01.cir.95.9.2254] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Intracoronary ultrasound (ICUS) imaging is potentially suitable to identify lesions at high risk of restenosis after percutaneous transluminal coronary angioplasty (PTCA), but it has not been studied systematically. METHODS AND RESULTS We recruited 200 patients in whom ICUS studies were performed after successful PTCA and related their ICUS parameters to 6-month follow-up quantitative coronary angiography. This was performed in 164 patients (82%), yielding 170 lesions for analysis. The overall incidence of a > or = 50% diameter stenosis at follow-up (categorical restenosis) was 29.4%. Quantitative ICUS parameters were weakly but significantly related to follow-up minimal luminal diameter on quantitative coronary angiography (lumen area: R2 = .36, P = .0001; vessel area: R2 = .29, P = .0002; plaque area: R2 = -.18, P = .021; percent obstruction: R2 = -.15, P = .05), but categorical restenosis was not significantly related to these parameters (P = .63, .77, .38, and .08, respectively). There were no significant predictors of restenosis in ICUS parameters of plaque morphology: eccentric versus concentric (P = 1.0), plaque type (hard, soft, or calcific, P = .98), or the number of calcified quadrants (P = .41). There were no significant predictors of restenosis in two predefined types of vessel-wall disruptions: (1) rupture: presence (P = .79), depth (partial versus complete, P = .85), or extent in quadrants (P = .6), and (2) dissection: presence (P = .31), depth (P = .82), or extent (P = .38). CONCLUSIONS Qualitative ICUS parameters after PTCA did not predict restenosis. A larger lumen and vessel area and a smaller plaque area by ICUS were associated with a larger angiographic minimal lumen diameter at follow-up, but these parameters were not significantly related to categorical restenosis.
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Affiliation(s)
- R J Peters
- Interuniversity Cardiology Institute of The Netherlands, Utrecht
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35
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von Birgelen C, Li W, Bom N, Serruys PW. Quantitative three-dimensional intravascular ultrasound. Semin Interv Cardiol 1997; 2:25-32. [PMID: 9546981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Three-dimensional (3-D) intravascular ultrasound (IVUS) allows for the visualization of entire coronary segments, provides more detailed insights into the geometry of atherosclerotic plaques and facilitates serial studies. Automated quantitative 3-D IVUS methods reduce the analysis time and the subjectivity of boundary tracing, and permit complex IVUS studies. The 3-D IVUS approach is not restricted to research applications, but may be used as a valuable clinical tool. Evaluation of the coronary segment of interest before catheter-based coronary interventions provides information which may facilitate the selection of interventional devices. Moreover, 3-D IVUS allows for a careful assessment of the procedural results and potential post-procedural complications. ECG-gated image acquisition, automated contour detection, and approaches using data of both 3-D IVUS and biplane angiography represent the recent progress in this field. Three-dimensional IVUS will surely gain further importance and become a routine technique, if the interest and research effort is sustained.
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Affiliation(s)
- C von Birgelen
- Thoraxcenter, University Hospital Rotterdam-Dijkzigt, The Netherlands
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36
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Li W, van der Steen AF, Lancée CT, Céspedes EI, Carlier S, Gussenhoven EJ, Bom N. Potentials of volumetric blood-flow measurement. Semin Interv Cardiol 1997; 2:49-54. [PMID: 9546984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Current intravascular ultrasound techniques produce real-time imaging of a vessel cross-section with a scan plane normal to blood flow. When randomly distributed blood particles travel through this ultrasound imaging plane, the received echo signals decorrelate as a function of time. The speed of such a decorrelation procedure is proportional to the flow velocity. This phenomenon provides a potential to estimate blood velocities by means of decorrelation analysis. In this paper, we present a method for measuring local blood velocity and quantifying volume flow directly from cross-sectional intravascular ultrasound data. This method is based on multiple decorrelation assessments with a sequence of radio frequency echo signals. The velocity measurement is obtained by comparing the measured decorrelation value with the prior knowledge of the beam characteristics of an intravascular ultrasound transducer. Volume flow is derived by integrating the cross-sectional area and its corresponding velocity vector over the vessel lumen. The decorrelation-based method was tested in vitro with a flow phantom. Measurements were also carried out in vivo in pig experiments to determine the usefulness of this method in clinical settings. Preliminary results of these experiments indicate that the proposed decorrelation method is able to extract cross-sectional velocity profiles and volumetric flow both in vitro and in vivo.
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Affiliation(s)
- W Li
- Thoraxcentre, Erasmus University Rotterdam, The Netherlands.
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37
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van der Steen AF, Rijsterborgh H, Lancee CT, Mastik F, Krams R, Verdouw PD, Roelandt JR, Bom N. Influence of data processing on cyclic variation of integrated backscatter and wall thickness in stunned porcine myocardium. Ultrasound Med Biol 1997; 23:405-414. [PMID: 9160908 DOI: 10.1016/s0301-5629(96)00227-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
This study was performed to investigate the relationship between the cyclic variation of integrated backscatter and myocardial wall thickening in stunned myocardium. Different definitions of cyclic variation were evaluated to be able to compare with other studies. Ultrasound data were acquired from 10 open-chested Yorkshire pigs (25-33 kg) at baseline, during regional ischemia and during 30 min of stunning, using a broadband ultrasound transducer (3-7 MHz) sutured directly upon the left ventricular myocardial wall. Cyclic variation of integrated backscatter and myocardial wall thickening were calculated using three definitions obtained from the literature. Independent of the definition, cyclic variation of wall thickness and integrated backscatter were blunted during acute ischemia and returned transiently to or above baseline during the first minute of reperfusion, followed by a gradual decrease to a level under baseline during stunning. An early return of the cyclic variation of the integrated backscatter was not observed in pigs, independent of the data processing used. The relationship between integrated backscatter and wall thickness was maintained.
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Affiliation(s)
- A F van der Steen
- Department of Cardiology, Thoraxcenter, Erasmus University Rotterdam, The Netherlands
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38
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Rijsterborgh H, van der Steen AF, Krams R, Mastik F, Lancée CT, Verdouw PD, Roelandt JR, Bom N. The relationship between myocardial integrated backscatter, perfusion pressure and wall thickness during isovolumic contraction: an isolated pig heart study. Ultrasound Med Biol 1996; 22:43-52. [PMID: 8928316 DOI: 10.1016/0301-5629(95)02030-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
To investigate the independent effect of myocardial wall thickness and myocardial perfusion pressure on integrated backscatter, experiments were designed in which integrated backscatter of normally perfused myocardial tissue was measured while changes in wall thickness during the cardiac cycle were reduced to a minimum. In nine blood-perfused isolated pig hearts, perfusion pressure was uncoupled from left ventricular pressure generation (Langendorff method) and isovolumic contraction and relaxation were realized by inserting a noncompressible water-filled balloon into the left ventricle. In a first experiment, at constant perfusion pressure (85 mmHg), the integrated backscatter (3-7 MHz), the myocardial wall thickness and the left ventricular pressure were determined simultaneously at various balloon volumes (5-25 mL). A quasistatic increase of balloon volume by 50% resulted in an average decrease of wall thickness of 6.5% (p < 0.01) and a mean increase in the integrated backscatter level of 1.1 dB (p < 0.01). Integrated backscatter levels increased statistically significant by 0.14 +/- 0.014 dB per percent decrease of wall thickness. Measurements of percentage end-systolic myocardial wall thickening ranged from -10% to +10%, mean 0.15 +/- 4.5% (NS from zero); whereas cyclic variation of integrated backscatter ranged from -3.9 to +3.9 dB, mean 0.19 +/- 1.5 dB (NS from zero). In a second experiment, at a constant midrange balloon volume, the same parameters were determined simultaneously at various perfusion pressures (20-120 mmHg). An increase in perfusion pressure by 50% resulted in a small but statistically significant increase of 1.5% in myocardial wall thickness, which could be explained by an increase of intravascular volume. The integrated backscatter levels did not change statistically significantly. Measurements of percentage end-systolic myocardial wall thickening ranged from -8.9 to +7.8%, mean 0.13 +/- 4.0% (NS from zero); whereas cyclic variation of integrated backscatter ranged from -1.8 to +4.2 dB, mean 0.37 +/- 1.3 dB (NS from zero). The magnitude of cyclic variation of integrated backscatter of myocardial tissue in a contractile state is reduced if myocardial muscle is prevented from normal thickening. In addition, changes in intravascular volume during the cardiac cycle have a negligible influence on the absolute backscatter level or its cyclic variation. We conclude, if only wall thickness and perfusion pressure are involved, that integrated backscatter is mainly determined by myocardial wall thickness.
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Affiliation(s)
- H Rijsterborgh
- Department of Cardiology, Erasmus University Rotterdam, The Netherlands
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39
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Abstract
After its introduction about two decades ago, transesophageal echocardiography (TEE) has rapidly evolved into an important diagnostic feature for the cardiologist, since it offers anatomic and hemodynamic information which cannot be obtained precordially. Part of this success was due to the developments in transducer technology which resulted in smaller probes with progressively better imaging qualities. A short review of past, recent and future developments of TEE phased array probes, in particular those at the Erasmus University in Rotterdam, will be given. Furthermore, this article discusses basic parameters of the transducer dictating image quality such as centre frequency, array aperture and focusing illustrated with several simulations. The simulations show that a poor design of the transducer will limit the resolution and will give artefacts in the two-dimensional image.
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Affiliation(s)
- K K Djoa
- Thoraxcentre Laboratory for Experimental Echocardiography, Erasmus University Rotterdam, The Netherlands
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40
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van der Lugt A, Gussenhoven EJ, Pasterkamp G, Bom N, Posthuma DJ, Stijnen T. Interobserver reproducibility of qualitative and quantitative analysis of intravascular ultrasound images before and after peripheral balloon angioplasty. Ultrasound Med Biol 1996; 22:399-404. [PMID: 8795166 DOI: 10.1016/0301-5629(96)00034-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In this study, interobserver agreement on intravascular ultrasound data obtained before and after balloon angioplasty (PTA) of the superficial femoral artery was assessed. Two observers analyzed intravascular ultrasound cross-sections from 38 patients. Interobserver agreement was good for soft and hard lesions, dissection and vascular damage (kappa values 0.61, 0.67, 0.69 and 0.66, respectively); moderate for eccentric lesions (kappa 0.45); fair for media ruptures (kappa 0.25); and poor for lipid deposits and plaque ruptures (kappa 0.0 and 0.04, respectively). Differences for the arc of normal wall and hard lesion were not significant, but were for dissection. There were no significant interobserver differences between area measurements. The coefficient of variation for free lumen area and media-bounded area before PTA was 17.2% and 10.5% and after PTA 11.2% and 9.2%, respectively. This study identified the intravascular ultrasound parameters that are reproducible.
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41
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Montauban van Swijndregt AD, The SH, Gussenhoven EJ, Lancée CT, Rijsterborgh H, de Groot E, van der Steen AF, Bom N, Ackerstaff RG. An in vitro evaluation of the line pattern of the near and far walls of carotid arteries using B-mode ultrasound. Ultrasound Med Biol 1996; 22:1007-1015. [PMID: 9004424 DOI: 10.1016/s0301-5629(96)00130-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
This in vitro study was executed to evaluate the double line pattern generated at both near and far walls of human carotid arteries using B-mode ultrasound. Therefore, extravascular (7.5 MHz) and intravascular (30 MHz) ultrasound imaging were performed at the same locations of the carotid artery. The thickness of the double line pattern of the extravascular image (7.5 MHz) was compared to the thickness of the intima-media complex seen on the corresponding intravascular image (30 MHz) and on the histologic section. At the far wall of the extravascular image, the measurements were executed at the leading edge of the echo. The data showed high correlation and agreement with the intravascular (r = 0.91, p < 0.001; mean(diff) = -0.01 and SDdiff = 0.12) and the histologic measurements (r = 0.87, p < 0.001; mean(diff) = -0.12 and SDdiff = 0.13). In addition, the results of the measurements of the intravascular image showed high correlations and agreement with the histologic data (r(near) = 0.86, p < 0.001; mean(diff) = -0.08 and SDdiff = 0.15, respectively, r(far) = 0.92, p < 0.001; mean(diff) = -0.12 and SDdiff = 0.12). For comparison with other studies, near wall measurements were also included. These had to be performed at the trailing edge of the echoes to be compatible with these studies. The results of the measurements of the extravascular image showed poor correlations and lack of agreement with those of the intravascular (r = 0.49, p = 0.03; mean(diff) = 0.09 and SDdiff = 0.25) and of the histologic (r = 0.37, p = 0.03; mean(diff) = 0.04 and SDdiff = 0.23) measurements. These results can easily be explained from the physical limitations of measuring at the trailing edges. We conclude that the double line pattern seen at the far wall of the extravascular image is representative of the intima-media complex.
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42
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Li W, van der Steen AF, Lancee CT, Honkoop J, Gussenhoven EJ, Bom N. Temporal correlation of blood scattering signals in vivo from radiofrequency intravascular ultrasound. Ultrasound Med Biol 1996; 22:583-590. [PMID: 8865555 DOI: 10.1016/0301-5629(96)00023-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
One limitation encountered using high frequency intravascular ultrasound (IVUS) is the echogenicity of blood, which increases dramatically at frequencies of 20-40 MHz. Because of the higher velocity of moving blood particles, the echo pattern of flowing blood shows more variations in time than that of the wall. To investigate the time-varying characteristics of the blood scattering measurements were performed on the radiofrequency (RF) data collected in vivo from five pig experiments. After positioning the echo catheter inside the iliac artery, an M-mode sequence of 30 RF traces was acquired at a high pulse repetition rate (5 kHz). The RF correlation time was measured on the regions of blood and the arterial wall. Two processing techniques, temporal averaging and correlation, were tested for suppression of the blood echo intensity. The correlation time Tc measured in the blood region was approximately 1 ms, which was shorter than that measured in the wall region (Tc >> 6 ms). The correlation values calculated in a small window showed a large variation in the blood region while the wall region produced a constant high output. After processing eight consecutive RF traces (delta T = 200 microseconds), the temporal averaging method results in a 50% intensity reduction in the blood region. Using the correlation output as a weighting function, the blood echo intensity can be further reduced to only 10% of its original value. Application of the RF correlation processing to a cross-sectional image data demonstrates the feasibility of this technique to remove most of the blood echoes and enhance the image contrast of the luminal interface.
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Affiliation(s)
- W Li
- Erasmus University Rotterdam, The Netherlands.
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43
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Affiliation(s)
- C T Lancée
- Thoraxcentre, Division of Cardiology, Erasmus University Rotterdam, The Netherlands
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44
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Djoa KK, Lancée CT, De Jong N, Linker DT, Bom N. Transesophageal transducer technology: an overview. Am J Card Imaging 1995; 9:79-86. [PMID: 7795382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Early developments and basic principles in the field of Transesophageal Echocardiography (TEE) probe technology are summarized. Mechanical and electronical sector scanners are compared, and several probe characteristics and image parameters are discussed. A short review of recent developments in TEE is given.
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Affiliation(s)
- K K Djoa
- Department of Biomedical Engineering, Thoraxcentre, Erasmus University, Rotterdam, The Netherlands
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45
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van der Heiden MS, de Kroon MG, Bom N, Borst C. Ultrasound backscatter at 30 MHz from human blood: influence of rouleau size affected by blood modification and shear rate. Ultrasound Med Biol 1995; 21:817-826. [PMID: 8571469 DOI: 10.1016/0301-5629(95)00012-g] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
High frequency intravascular ultrasound may show a high intensity backscatter from blood which hampers the discrimination between lumen and arterial wall. In this study, the acoustic behaviour of blood at 30 MHz in relation to rouleau size was analyzed. In a Couette viscometer, high frequency (20-40 MHz) backscatter data from normal and modified blood samples from eight volunteers were obtained at shear rates from 0 to 1000 s-1. The acoustic behaviour of blood was quantified by the integrated backscatter power and the spectral slope of the backscatter coefficient. Backscatter from blood depended on rouleau size. At a shear rate of zero, both whole blood and rouleau-enhanced blood showed a 11-dB-higher integrated backscatter power than rouleau-suppressed blood, which itself was 10 dB higher than that of hemolysed blood, the latter showing a 6-dB-higher backscatter than saline. Platelets did not contribute to the backscatter power. Plasma and saline produced no detectable integrated backscatter power other than noise. The spectral slope of whole and rouleau-enhanced blood was small (1 and 0.5, respectively), whereas rouleau-suppressed blood and hemolysed blood (both with a slope of 3.3) behaved almost like a Rayleigh scattering medium (slope = 4). The backscatter from rouleau-suppressed blood showed no shear rate dependence. At low shear rates ( < 0.8 s-1 for integrated backscatter power and < 0.2 s-1 for the spectral slope), whole blood and rouleau-enhanced blood tended to the results from the static situation (no shear). At high shear rates ( > 80 s-1 for integrated backscatter power and >11 s-1 for spectral slope), these samples tended to the results of rouleau-suppressed blood. Ultrasound backscatter at 30 MHz from human blood is only caused by red blood cells. With increasing aggregate (rouleau) size, the integrated backscatter power increased by 11 dB, and the spectral slope decreased from 3.3 to 1.
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46
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Pasterkamp G, van der Heiden MS, Post MJ, Borst C, Gussenhoven EJ, Pieterman H, van Urk H, Bom N. Discrimination of intravascular lumen and dissections in single intravascular ultrasound images using subtraction, conventional averaging and saline flush. Ultrasound Med Biol 1995; 21:149-156. [PMID: 7571124 DOI: 10.1016/s0301-5629(94)00106-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
With current 30-MHz intravascular ultrasound systems, flowing blood may cause considerable backscatter which in real-time images is characterized by dynamic speckle. However, in a single intravascular ultrasound image (still-frame) the discrimination between arterial lumen and wall may be difficult due to the frozen intraluminal speckle, particularly in the presence of dissections. We compared subtraction, averaging and saline flush as methods to improve the discrimination between arterial lumen and wall in a single image. The real-time images served as gold standard. In 22 patients who underwent peripheral balloon angioplasty, ultrasound images obtained from 84 sites were examined. The sensitivity and specificity of detecting dissections were in the subtraction image 85% and 100%, in the averaged image 57% and 96%, and in the saline flush image 58% and 86%, respectively. Subtraction is a promising method to outline the irregular lumen in a single image.
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Affiliation(s)
- G Pasterkamp
- Heart Lung Institute, Utrecht University Hospital, The Netherlands
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47
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Gerritsen GP, Gussenhoven EJ, The SH, Pieterman H, v d Lugt A, Li W, Bom N, van Dijk LC, Du Bois NA, van Urk H. Intravascular ultrasonography before and after intervention: in vivo comparison with angiography. J Vasc Surg 1993; 18:31-40. [PMID: 8326657 DOI: 10.1067/mva.1993.41957] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
PURPOSE To compare the additional capacity of intravascular ultrasonography versus angiography to assess morphologic features and lumen dimension, 37 patients undergoing vascular intervention of the common iliac or superficial femoral artery were studied. A total of 181 ultrasonic cross sections were analyzed (94 before and 87 after intervention). METHODS AND RESULTS Before intervention intravascular ultrasonography distinguished normal cross sections (n = 17) from cross sections with a lesion (n = 77): soft (51%) versus hard (31%) lesions, and eccentric (75%) versus concentric (7%) lesions. After intervention intravascular ultrasonography documented dissection (43%), plaque rupture (10%), and internal elastic lamina rupture (8%). A good correlation between ultrasonography and angiography was found for the recognition of eccentric or concentric lesions and dissections. The degree of stenosis was assessed semiquantitatively by visual estimation of the degree of luminal narrowing from the angiograms and intravascular ultrasonic images and was categorized into four classes: (1) normal, (2) less than 50% stenosis, (3) 50% to 90% stenosis, and (4) greater than 90% stenosis. Intravascular ultrasonographic assessment of stenosis was in agreement with angiography in 78% of cases and showed more severe lesions in 22% before intervention. Similar data were observed after intervention, with 72% of results being in agreement and 28% of cases showing more severe lesions. The degree of stenosis was also quantitatively evaluated by computer-aided analysis of the intravascular ultrasonic images. The semiquantitative analysis by intravascular ultrasonography corresponded well with the quantitative analysis done by the computer-aided system. When both echography and angiography suggested that arteries were normal, quantitative intravascular ultrasonography identified lesions that occupied an average of 18% of the cross-sectional area of the vessel. CONCLUSIONS This in vivo study shows that intravascular ultrasonography is capable of documenting detailed morphologic features. Semiquantitative ultrasonic data correlate closely with those of angiography, albeit stenoses were assessed as more severe on ultrasonography.
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Affiliation(s)
- G P Gerritsen
- Department of Vascular Surgery, University Hospital Dijkzigt, The Netherlands
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48
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Slager CJ, Schuurbiers JC, Oomen JA, Bom N. Electrical nerve and muscle stimulation by radio frequency surgery: role of direct current loops around the active electrode. IEEE Trans Biomed Eng 1993; 40:182-7. [PMID: 8319969 DOI: 10.1109/10.212058] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Tissue cutting by electrosurgery is often accompanied with stimulation of nerves and muscles, despite the high frequency of the alternating current being applied. The main source of this stimulation is thought to be the generation of low frequency current by the nonlinear sparking process. However, measurement of this low-frequency current, in the generator electrode's circuit, showed relatively small values, barely sufficient to support this hypothesis. In this study more powerful low frequency current could be identified, indeed also originating from the nonlinear sparking process. Local direct and low frequency currents, at a level of tens of milliamperes, appeared to be generated between different sites of the active electrode-tissue interface. Probably these local currents have not been noticed before as they cannot be detected in the outer chain of generator, electrodes, and connecting wires. This finding may explain why most measures, intended to prevent stimulation by modifying this outer chain, had only limited success.
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Affiliation(s)
- C J Slager
- University of Hospital of Rotterdam-Dijkzigt, The Netherlands
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49
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Di Mario C, Madretsma S, Linker D, The SH, Bom N, Serruys PW, Gussenhoven EJ, Roelandt JR. The angle of incidence of the ultrasonic beam: a critical factor for the image quality in intravascular ultrasonography. Am Heart J 1993; 125:442-8. [PMID: 8427139 DOI: 10.1016/0002-8703(93)90024-4] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The effects of the angle of incidence of the ultrasound beam on the image quality were studied in 21 pressurized arterial specimens examined with a 30 MHz intravascular ultrasonographic catheter. When the ultrasonographic catheter was in an eccentric position in the vessel lumen, the videodensity of the segments of the vessel wall with the least favorable angle of interrogation (a shift of 49 +/- 6 degrees from the tangent to the tissue surface) was 27% +/- 19% lower than the videodensity measured with the catheter in the center of the lumen. When the catheter was placed in a position that was not parallel to the long axis of the vessel, a further decrease was observed, especially in the vessel wall opposite the position of the catheter. An artificial dissection was induced in eight specimens. Dropouts that involved the dissection plane and the underlying structures were produced with positions of the echographic catheter inducing a narrow angle between ultrasound beam and dissection plane. These experimentally induced artifacts were compared with similar findings from the in vivo evaluation of peripheral and coronary arteries. The angle of incidence of the ultrasound beam is a major determinant of the image quality in intravascular ultrasonography. Angle-dependent artifacts occur with eccentric and noncoaxial positions of the ultrasonographic catheter and, in particular, with imaging of large intraluminal dissections. Awareness of this problem may prevent image misinterpretation and has relevance for future improvement of catheter technology and design.
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Affiliation(s)
- C Di Mario
- Department of Cardiology, Erasmus University Rotterdam, The Netherlands
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Rijsterborgh H, Mastik F, Lancée CT, Verdouw P, Roelandt J, Bom N. Ultrasound myocardial integrated backscatter signal processing: frequency domain versus time domain. Ultrasound Med Biol 1993; 19:211-219. [PMID: 8511827 DOI: 10.1016/0301-5629(93)90111-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In the literature, different forms of measuring the ultrasound power returned by myocardial tissue are reported. Frequency domain methods will give the maximum frequency information, whereas time domain methods are limited in bandwidth, but more practical to realize. It was the purpose of this study to compare the various methods of signal processing. High frequency ultrasound signals from a pig's myocardium, digitally recorded during normal contractile performance, were analyzed by six different methods of signal processing to obtain estimates of backscatter power. The myocardial tissue characterization parameters studied were the integrated power as well as its cyclic variation during the cardiac cycle. A total number of 8109 ultrasound traces obtained in 16 pigs were processed. The study included three signal processing methods in the frequency domain: frequency compensated integrated backscatter calculated over both a large (4 MHz, method 1) as well as a small frequency bandwidth (2 MHz, method 2) and uncompensated integrated backscatter (method 3), and three methods in the time domain: high frequency signal squared and integrated (method 4), mean rectified signal level (method 5) and mean signal level after logarithmic compression and envelope detection (method 6). The random measurement variation (including beat-to-beat variation) was analyzed as well as the paired differences of the backscatter parameters obtained by the respective methods as compared with the only theoretically correct method in the time domain (method 4). The magnitudes of the random measurement variation expressed as a standard deviation (SD) were comparable (range 0.93-1.2 dB) except for method 6 (0.61 dB), where the measurement variation is decreased by the logarithmic compression.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- H Rijsterborgh
- Thoraxcenter, Erasmus University Rotterdam, The Netherlands
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