Thermal expansion imaging for monitoring lesion depth using M-mode ultrasound during cardiac RF ablation: in vitro study

  • Peter Baki
  • Sergio J. Sanabria
  • Gabor Kosa
  • Gabor Szekely
  • Orcun Goksel
Original Article

Abstract

Purpose

We demonstrate a novel method for automatic direct lesion depth (LD) tracking during coagulation from time series of a single A-mode ultrasound (US) transducer custom fit at the tip of a RFA catheter. This method is named thermal expansion imaging (TEI).

Methods

A total of 35 porcine myocardium samples were ablated (LD 0.5–5 mm) while acquiring US, electrical impedance (EI) and contact force (CF) data. US images are generated in real time in terms of echo intensity (M-mode) and phase (TEI). For TEI, displacements between US time series are estimated with time-domain cross-correlation. A modified least squares strain estimation with temporal and depth smoothing reveals a thermal expansion boundary (TEB)—negative zero-crossing of temporal strain—which is associated to the coagulated tissue front.

Results

M-mode does not reliably delineate RFA lesions. TEI images reveal a traceable TEB with RMSE \(=\) 0.50 mm and \(R^{2}=0.85\) with respect to visual observations. The conventional technique, EI, shows lower \(R^{2}=0.7\) and \(>\)200 % variations with CF. The discontinuous time progression of the TEB is qualitatively associated to tissue heterogeneity and CF variations, which are directly traceable with TEI. The speed of sound, measured in function of tissue temperature, increases up to a plateau at 55 \(^{\circ }\hbox {C}\), which does not explain the observed strain bands in the TEB.

Conclusions

TEI successfully tracks LD in in vitro experiments based on a single US transducer and is robust to catheter/tissue contact, ablation time and even tissue heterogeneity. The presence of a TEB suggests thermal expansion as the main strain mechanism during coagulation, accompanied by compression of the adjacent non-ablated tissue. The isolation of thermally induced displacements from in vivo motion is a matter of future research. TEI is potentially applicable to other treatments such as percutaneous RFA of liver and high-intensity focused ultrasound.

Keywords

Ultrasound Strain imaging Lesion control Radio-frequency ablation 

References

  1. 1.
    De Luna AB (2012) Clinical electrocardiography: a textbook. Wiley, Chichester, UKCrossRefGoogle Scholar
  2. 2.
    Kannel WB, Abbot RD, Savage DD, McNamara PM (1982) Epidemiologic features of chronic atrial fibrillation: the framingham study. N Engl J Med 306(17):1018–1022CrossRefPubMedGoogle Scholar
  3. 3.
    Ostrander L, Brandt RL, Kjelsberg MO, Epstein FH (1965) Electrocardiographic findings among the adult population of a total natural community, tecumseh, michigan. Circulation 31(6):888–898CrossRefPubMedGoogle Scholar
  4. 4.
    McRury ID, Haines DE (1996) Ablation for the treatment of arrhythmias. Proc IEEE 84(3):404–416CrossRefGoogle Scholar
  5. 5.
    Haissaguerre M, Jais P, Shah DC (1998) Spontaneous initiatoin of atrial fibrillation by ectopic beats originating in the pulmonary veins. N Engl J Med 339:659–666CrossRefPubMedGoogle Scholar
  6. 6.
    Haines DE (1993) The biophysics of radiofrequency catheter ablation in the heart: the importance of temperature monitoring. Pacing Clin Electrophysiol 16(3):586–591CrossRefPubMedGoogle Scholar
  7. 7.
    Nath S, Lynch C, Whayne JG, Haines DE (1993) Cellular electrophysiological effects of hyperthermia on isolated guinea pig papillary muscle. Implications for catheter ablation. Circulation 88(4):1826–1831CrossRefPubMedGoogle Scholar
  8. 8.
    Matsudaira K, Nakagawa H, Wittkampf FH, Yamanashi WS, Imai S, Pitha JV, Lazzara R, Jackman WM (2003) High incidence of thrombus formation without impedance rise during radiofrequency ablation using electrode temperature control. Pacing Clin Electrophysiol 26(5):1227–1237CrossRefPubMedGoogle Scholar
  9. 9.
    Cappato R, Calkins H, Chen S-A (2010) Updated worldwide survey on the methods, efficacy, and safety of catheter ablation for human atrial fibrillation. Circ Arrhythm Electrophsiol 3:32–38CrossRefGoogle Scholar
  10. 10.
    Shah D (2011) A critical appraisal of cardiac ablation technology for catheter-based treatment of atrial fibrillation. Expert Rev Med Devices 8(1):49–55CrossRefPubMedGoogle Scholar
  11. 11.
    Haemmerich D (2010) Biophysics of radiofrequency ablation. Crit Rev Biomed Eng 38(1):53–63CrossRefPubMedGoogle Scholar
  12. 12.
    Perez FJ, Wood MA, Schubert CM (2006) Effects of gap geometry on conduction through discontinuous radiofrequency lesions. Circulation 113:1723–1729CrossRefPubMedGoogle Scholar
  13. 13.
    Okumura Y, Johnson SB, Bunch TJ, Henz BD, O’Brien CJ, Packer DL (2008) A systematical analysis of in vivo contact forces on virtual catheter tip/tissue surface contact during cardiac mapping and intervention. J Cardiovasc Electrophysiol 19(6):632–640CrossRefPubMedGoogle Scholar
  14. 14.
    Blouin LT, Marcus FI, Lampe L (1991) Assessment of effects of a radiofrequency energy field and thermistor location in an electrode catheter on the accuracy of temperature measurement. Pacing Clin Electrophysiol 14(5):807–813CrossRefPubMedGoogle Scholar
  15. 15.
    Chugh SS, Chan RC, Johnson SB, Packer DL (1999) Catheter tip orientation affects radiofrequency ablation lesion size in the canine left ventricle. Pacing Clin Electrophysiol 22(3):413–420CrossRefPubMedGoogle Scholar
  16. 16.
    Lustgarten DL, Spector PS (2008) Ablation using irrigated radiofrequency: a hands-on guide. Heart Rythm 5(6):899–902CrossRefGoogle Scholar
  17. 17.
    Shah DC, Lambert H, Nakagawa H, Lagenkamp A, Aeby N, Leo G (2010) Area under the real-time contact force curve (force-time integral) predicts radiofrequency lesion size in an in vitro contractile model. J Cardiovasc Electrophysiol 21(9):1038–1043CrossRefPubMedGoogle Scholar
  18. 18.
    Yokoyama K, Nakagawa H, Shah DC, Lambert H, Giovanni L, Aeby N, Ikeda A, Pitha JV, Sharma T, Lazzara R, Jackman WM (2008) Novel contact force sensor incorporated in irrigated radiofrequency ablation catheter predicts lesion size and incidence of steam pop and thrombus/clinical perspective. Circ Arrhythm Electrophsiol 1(5):354–362CrossRefGoogle Scholar
  19. 19.
    Betensky BP, Jauregui M, Campos B, Michele J, Marchlinski FE, Oley L, Wylie B, Robinson D, Gerstenfeld EP (2012) Use of a novel endoscopic catheter for direct visualization and ablation in an ovine model of chronic myocardial infarction. Circulation 126:2065–2072CrossRefPubMedGoogle Scholar
  20. 20.
    Kolandaivelu A, Zviman MM, Castro V, Lardo AC, Berger RD, Halperin HR (2010) Non-invasive assessment of tissue heating during cardiac radiofrequency ablation using MRI thermography/clinical perspective. Circ Arrhythm Electrophsiol 3:521–529CrossRefGoogle Scholar
  21. 21.
    Ranjan R, Koholmovski EG, Blauer J (2012) Identification and acute targeting of gaps in atrial ablation lesion sets using a real-time magnetic resonance imaging system. Circ Arrhythm Electrophsiol 5:1130–1135CrossRefGoogle Scholar
  22. 22.
    Hoskins P, Martin K, Thrush A (2010) Diagnostic ultrasound: physics and equipment. Cambridge University Press, New YorkGoogle Scholar
  23. 23.
    Bush N, Rivens I, Ter Haar G, Bamber J (1993) Acoustic properties of lesions generated with an ultrasound therapy system. Ultrasound Med Biol 19(9):789–801CrossRefPubMedGoogle Scholar
  24. 24.
    Hynynen K (1997) Review of ultrasound therapy. In: Proceedings IEEE ultrasonics symposium, pp 1305–1313Google Scholar
  25. 25.
    Maleke C, Konofagou EE (2008) Harmonic motion imaging for focused ultrasound: a fully integrated technique for sonification and monitoring of thermal ablation in tissues. Phys Med Biol 53(6):1773–1793CrossRefPubMedGoogle Scholar
  26. 26.
    ter Haar G, Sinnett D, Rivens I (1995) Ultasound focal beam surgery. Ultrasound Med Biol 21(9):1089–1100CrossRefPubMedGoogle Scholar
  27. 27.
    Kumon RE, Gudur MS, Zhou Y, Deng CX (2012) High-frequency ultrasound M-mode imaging for identifying lesion and bubble activity during high-intensity focused ultrasound ablation. Ultrasound Med Biol 38(4):626–641CrossRefPubMedCentralPubMedGoogle Scholar
  28. 28.
    Bunch TJ, Bruce GK, Johnson SB, Sarabanda A, Milton MA, Packer DL (2004) Analysis of catheter-tip (8-mm) and actual tissue temperatures achieved during radiofrequency ablation at the orifice of the pulmonary vein. Circulation 110(19):2988–2995CrossRefPubMedGoogle Scholar
  29. 29.
    Wright M, Harks E, Deladi S, Suijver F, Barley M, van Dusschoten A, Fokkenrood S, Zuo F, Sacher F, Hocini M, Haïssaguerre M, Jäis P (2011) Real-time lesion assessment using a novel combined ultrasound and radiofrequency ablation catheter. Heart Rythm 8(2):304–312CrossRefGoogle Scholar
  30. 30.
    Eyerly SA, Hsu SJ, Agashe SH, Trahey GE, Li Y, Wolf PD (2010) An in vitro assessment of acoustic radiation force impulse imaging for visualizing cardiac radiofrequency ablation lesions. J Cardiovasc Electrophysiol 21(5):557–563CrossRefPubMedCentralPubMedGoogle Scholar
  31. 31.
    Seo CH, Shi Y, Huang SW, Kim K, O’Donnell M (2011) Thermal strain imaging: a review. Interface Focus 1(4):649–664CrossRefPubMedCentralPubMedGoogle Scholar
  32. 32.
    Miller NR, Bamber JC, Ter Haar G (2004) Imaging of temperature-induced echo strain: preliminary in vitro study to assess feasibility for guiding focused ultrasound surgery. Ultrasound Med Biol 30(3):345–356CrossRefPubMedGoogle Scholar
  33. 33.
    Varghese T, Zagzebski JA, Chen Q, Techavipoo U, Frank G, Johnson C, Wright A, Lee FT Jr (2002) Ultrasound monitoring of temperature change during radiofrequency ablation: preliminary in-vivo results. Ultrasound Med Biol 28(3):321–329CrossRefPubMedGoogle Scholar
  34. 34.
    Seo CH, Stephens D, Cannata J, Dentinger A, Lin F, Park S, Wildes D, Thomenius KE, Chen P, Nguyen T, de La Rama A, Jeong JS, Mahajan A, Shivkumar K, Nikoozadeh A, Oralkan O, Truong U, Sahn DJ, Khuri-Yakub PT, O’Donnell M (2011) The feasibility of using thermal strain imaging to regulate energy delivery during intracardiac radio-frequency ablation. IEEE Trans Ultrason Ferroelectr Freq Control 58(7):1406–1417CrossRefPubMedCentralPubMedGoogle Scholar
  35. 35.
    Souchon R, Bouchoux G, Maciejko E, Lafon C, Cathignol D, Bertrand M, Chapelon JY (2005) Monitoring the formation of thermal lesions with heat-induced echo-strain imaging: a feasibility study. Ultrasound Med Biol 31(2):251–259CrossRefPubMedGoogle Scholar
  36. 36.
    Baki PS (2014) Sensorized cardiac radiofrequency ablation system for lesion depth assessment. PhD Thesis, ETH ZurichGoogle Scholar
  37. 37.
    Baki PS, Szekely G, Kosa G (2013) Design and characterization of a novel, robust, tri-axial force sensor. Sensor Actuat A Phys 192:101–110CrossRefGoogle Scholar
  38. 38.
    Cao H, Tungjitkusolmun S, Choi YB, Tsai J, Vorperian VR, Webster JG (2002) Using electrical impedance to predict catheter-endocardial contact during rf cardiac ablation. IEEE Trans Biomed Eng 49(3):247–253CrossRefPubMedGoogle Scholar
  39. 39.
    Wittkampf FH, Hauer RN, de Medina ER (1989) Control of radiofrequency lesion size by power regulation. Circulation 80(4):962–968CrossRefPubMedGoogle Scholar
  40. 40.
    Stephens DN, O’Donnell M, Thomenius K, Dentinger A, Wildes D, Chen P, Shung KK, Cannata J, Khuri-Yakub P, Oralkan O, Mahajan A, Shivkumar K, Sahn DJ (2009) Experimental studies with a 9f forward-looking intracardiac imaging and ablation catheter. J Ultrasound Med 28(2):207–215Google Scholar
  41. 41.
    Kallel F, Ophir J (1997) A least-squares strain estimator for elastography. Ultrasonic Imaging 19:195–208CrossRefPubMedGoogle Scholar
  42. 42.
    Khurana I (2009) Textbook of medical physiology. Elsevier, DelhiGoogle Scholar
  43. 43.
    Lu J, Ying H, Sun Z, Motamedi M, Bell B, Sheppard L C (1996) In vitro measurement of speed of sound during coagulate tissue heating. In: Proceedings IEEE ultrasonics symposium, pp 1299–1302Google Scholar
  44. 44.
    Masugata H, Mizushige K, Senda S, Kinoshita A, Sakamoto H, Sakamoto S, Matsuo H (1999) Relationship between myocardial tissue density measured by microgravimetry and sound speed measured by acoustic microscopy. Ultrasound Med Biol 25(9):1459–1463CrossRefPubMedGoogle Scholar
  45. 45.
    van Sonnenberg E, Livraghi T, Mueller PR, McMuller W, Golbiati L, Silverman SG (2008) Tumor ablation: principles and practice. Springer, New YorkGoogle Scholar
  46. 46.
    Livraghi T, Goldberg SN, Lazzaroni S, Meloni F, Solbiati L, Gazelle GS (1999) Small hepatocellular carcinoma: treatment with radio-frequency ablation versus ethanol injection. Radiology 210:655–661CrossRefPubMedGoogle Scholar

Copyright information

© CARS 2015

Authors and Affiliations

  1. 1.Computer Vision LaboratoryETH ZurichZurichSwitzerland
  2. 2.School of Mechanical Engineering, Faculty of EngineeringTel Aviv UniversityTel AvivIsrael

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