Optimisation of ultrasound liver perfusion through a digital reference object and analysis tool

[EN] Background Conventional ultrasound (US) provides important qualitative information, although there is a need to evaluate the influence of the input parameters on the output signal and standardise the acquisition for an adequate quantitative perfusion assessment. The present study analyses how the variation in the input parameters influences the measurement of the perfusion parameters. Methods A software tool with simulator of the conventional US signal was created, and the influence of the different input variables on the derived biomarkers was analysed by varying the image acquisition configuration. The input parameters considered were the dynamic range, gain, and frequency of the transducer. Their influence on mean transit time (MTT), the area under the curve (AUC), maximum intensity (MI), and time to peak (TTP) parameters as outputs of the quantitative perfusion analysis was evaluated. A group of 13 patients with hepatocarcinoma was analysed with both a commercial tool and an in-house developed software. Results The optimal calculated inputs which minimise errors while preserving images¿ readability consisted of gain of 15¿dB, dynamic range of 60¿dB, and frequency of 1.5¿MHz. The comparison between the in-house developed software and the commercial software provided different values for MTT and AUC, while MI and TTP were highly similar. Conclusion Input parameter selection introduces variability and errors in US perfusion parameter estimation. Our results may add relevant insight into the current knowledge of conventional US perfusion and its use in lesions characterisation, playing in favour of optimised standardised parameter configuration to minimise variability.Alberich-Bayarri, Á.; Tomás-Cucarella, J.; Torregrosa-Lloret, A.; Saiz Rodríguez, FJ.; Martí-Bonmatí, L. (2019). Optimisation of ultrasound liver perfusion through a digital reference object and analysis tool. European Radiology Experimental. 3:1-10. https://doi.org/10.1186/s41747-019-0086-5S1103Parker JM, Weller MW, Feinstein LM et al (2013) Safety of ultrasound contrast agents in patients with known or suspected cardiac shunts. Am J Cardiol 112:1039–1045.Dhamija E, Paul SB (2014) Role of contrast enhanced ultrasound in hepatic imaging. Trop Gastroenterol 35:141–151.Wang XY, Kang LK, Lan CY (2014) Contrast-enhanced ultrasonography in diagnosis of benign and malignant breast lesions. Eur J Gynaecol Oncol 35:415–420.Wang S, Yang W, Zhang H, Xu Q, Yan K (2015) The role of contrast-enhanced ultrasound in selection indication and improveing diagnosis for transthoracic biopsy in peripheral pulmonary and mediastinal lesions. Biomed Res Int 2015:231782.Green MA, Mathias CJ, Willis LR, et al (2007) Assessment of Cu-ETS as a PET radiopharmaceutical for evaluation of regional renal perfusion. Nucl Med Biol 34:247–255.Daghini E, Primak AN, Chade AR, et al (2007) Assessment of renal hemodynamics and function in pigs with 64-section multidetector CT: comparison with electron-beam CT. Radiology 243:405–412.Martin DR, Sharma P, Salman K, et al (2008) Individual kidney blood flow measured with contrast-enhanced first-pass perfusion MR imaging. Radiology 246:241–248.Tang MX, Mulvana H, Gauthier T, et al (2011) Quantitative contrast-enhanced ultrasound imaging: a review of sources of variability. Interface Focus 1:520–539.Gauthier TP, Averkiou MA, Leen EL (2011) Perfusion quantification using dynamic contrast-enhanced ultrasound: the impact of dynamic range and gain on time-intensity curves. Ultrasonics 51:102–106.Möller I, Janta I, Backhaus M, et al (2017) The 2017 EULAR standardised procedures for ultrasound imaging in rheumatology. Ann Rheum Dis. 76:1974–1979.Pitre-Champagnat S, Coiffier B, Jourdain L, Benatsou B, Leguerney I, Lassau N (2017) Toward a standardization of ultrasound scanners for dynamic contrast-enhanced ultrasonography: methodology and phantoms. Ultrasound Med Biol. https://doi.org/10.1016/j.ultrasmedbio.2017.06.032Shunichi S, Hiroko I, Fuminori M, Waki H (2009) Definition of contrast enhancement phases of the liver using a perfluoro-based microbubble agent, perflubutane microbubbles. Ultrasound Med Biol 35:1819–1827. doiFairbank WM Jr, Scully MO (1977) A new noninvasive technique for cardiac pressure measurement: resonant scattering of ultrasound from bubbles. IEEE Trans Biomed Eng 24:107–110.Malm S, Frigstad S, Helland F, Oye K, Slordahl S, Skjarpe T (2005) Quantification of resting myocardial blood flow velocity in normal humans using real-time contrast echocardiography. A feasibility study. Cardiovasc Ultrasound 3:16.Arditi M, Frinking PJ, Zhou X, Rognin NG (2006) A new formalism for the quantification of tissue perfusion by the destruction-replenishment method in contrast ultrasound imaging. IEEE Trans Ultrason Ferroelectr Freq Control 53:1118–1129.Savic RM, Jonker DM, Kerbusch T, Karlsson MO (2007) Implementation of a transit compartment model for describing drug absorption in pharmacokinetic studies. J Pharmacokinet Pharmacodyn 34:711–726.Averkiou M, Lampaskis M, Kyriakopoulou K, et al (2010) Quantification of tumor microvascularity with respiratory gated contrast enhanced ultrasound for monitoring therapy. Ultrasound Med Biol 36:68–77.Kuenen MP, Mischi M, Wijkstra H (2011) Contrast-ultrasound diffusion imaging for localization of prostate cancer. IEEE Trans Med Imaging 30:1493–1502.Garcia D, Le Tarnec L, Muth S, Montagnon E, Porée J, Cloutier G(2013) Stolt’s f-k migration for plane wave ultrasound imaging. IEEE Trans Ultrason Ferroelectr Freq Control 60:1853–1867.Brands J, Vink H, Van Teeffelen JW (2011) Comparison of four mathematical models to analyze indicator-dilution curves in the coronary circulation. Med Biol Eng Comput 49:1471–1479.Zhou JH, Cao LH, Zheng W, Liu M, Han F, Li AH (2011) Contrast-enhanced gray-scale ultrasound for quantitative evaluation of tumor response to chemotherapy: preliminary results with a mouse hepatoma model. AJR Am J Roentgenol 196:W13-17.Wei K, Jayaweera AR, Firoozan S, Linka A, Skyba DM, Kaul S (1998) Quantification of myocardial blood flow with ultrasoundinduced destruction of microbubbles administered as a constant venous infusion. Circulation 97:473–483Riascos P, Velasco-Medina J (2005) Efectos Biológicos y Consideraciones de Seguridad en Ultrasonido. Available via https://www.yumpu.com/es/document/view/15350629/efectos-biologicos-y-consideraciones-de-seguridad-en-ultrasonidode Jong N, ten Cate FJ, Vletter WB, Roelandt JR (1993) Quantification of transpulmonary echocontrast effects. Ultrasound Med Biol 19:279–288Quaia E (2011) Assessment of tissue perfusion by contrast-enhanced ultrasound. Eur Radiol 21:604–615

Desarrollo de Protocolos de Verificación Operativa en Equipos Electromédicos

Este proyecto se ha realizado por la necesidad de elaborar un mantenimiento preventivo y correctivo de un conjunto de equipos de instrumentación biomédica que se encuentran en un hospital con el fin, de procurar que estos funcionen correctamente y sean seguros para empleados y pacientes. Con este trabajo se pretende realizar un estudio de los niveles de riesgo a los que un paciente puede estar sometido en un entorno hospitalario y cómo es posible prevenirlos, además, se proponen una serie de protocolos de verificación de algunos equipos de instrumentación biomédica que se encuentran en un hospital. Este desarrollo incluye una verificación preventiva del equipo y una verificación en caso de mantenimiento. Estos protocolos se basan en la normativa vigente en la fecha de publicación de ente texto y sobre todo en las especificaciones del propio fabricante.Tomás Cucarella, J. (2013). Desarrollo de Protocolos de Verificación Operativa en Equipos Electromédicos. Universitat Politècnica de València. http://hdl.handle.net/10251/36046Archivo delegad

Prácticas de simulación de procesos industriales

Alonso Campos, E.; Tomas Cucarella, J. (2009). Prácticas de simulación de procesos industriales. http://hdl.handle.net/10251/29717.Archivo delegad