The Effects of Residual Temperature Rise on Ultrasound Heating
2007; Elsevier BV; Volume: 33; Issue: 3 Linguagem: Inglês
10.1016/j.ultrasmedbio.2006.09.008
ISSN1879-291X
Autores Tópico(s)Photoacoustic and Ultrasonic Imaging
ResumoRecently, Karagoz and Kartal 2006 Karagoz I. Kartal M.K. Evaluation of nonscanned mode soft-tissue thermal index in the presence of the residual temperature rise. Ultrasound Med Biol. 2006; 32: 741-750 Abstract Full Text Full Text PDF PubMed Scopus (5) Google Scholar considered the temperature rise ΔT in tissue at the focus of a stationary transducer, which is on for some time, after which an off-period follows, which finally is followed by a second on-period. The temperature rise caused by the first heating period remaining at (the beginning of) the second heating period is called the residual temperature rise (see their Fig. 1). This paper contains a surprising result: continuous heating (their Fig. 2) gives a smaller temperature rise than heating at the same power level interrupted for a certain period (their Fig. 4). Fig. 2Temperature rise as a function of time calculated with method indicated in this Letter. Open triangle: continuous heating (source A); Open diamond: heating stopped at t = 500 s (sources A and B); Filled diamond: heating stopped at t = 500 and resumed at t = 550 s (Sources A, B and C). View Large Image Figure Viewer Download Hi-res image Response to Dr. Lubber’s LetterUltrasound in Medicine and BiologyVol. 33Issue 3PreviewIn our previous papers (Karagoz and Kartal 2005; 2006), we calculated the residual temperature rise (RTR) at the focus of a transducer by assuming that the uniform temperature field occurs at the end of the first ultrasound examination to obtain worst-case temperature rise. After all, Lubbers (2006) theoretically proposed that there is no need to consider the effect of residual temperature rise for the case of a single stationary transducer. Although Lubbers (2006) superimposed the effects of several heat sources to calculate the temperature rise, experimental results obtained by Horder et al. Full-Text PDF
Referência(s)