Talk:Photoacoustic imaging

message: PAT should definitely NOT be merged with photoacoustic imaging, since PAT is one specific category, which photoacoustics imaging describes the full physics phenomenon. This is akin to comparing X-Ray to CT. AXu.VSI (talk) 12:21, 7 July 2010 (UTC)
thread_title: PAT

message: Photoacoustic Imaging (originally called Optoacoustic Imaging) is a method of image acquisition and reconstruction based on time-resolved detection of acoustic pressure profiles induced in tissue through absorption of optical pulses under irradiation conditions of temporal pressure confinement during optical energy deposition [A.A. Oraevsky, A.A. Karabutov: “Optoacoustic Tomography ”, in Biomedical Photonics Handbook, ed. By T. Vo-Dinh, CRC Press, 2003, Vol. PM125, Chapter 34, pp. 34/1-34/34]. The term “irradiation conditions of temporal pressure confinement” means that optical energy (or other heat-generating energy) must be delivered to tissue faster than resulting acoustic wave can propagate the distance in tissue equal to the desirable spatial resolution. For example, having desirable resolution of optoacoustic images of 15 µm, and the speed of sound propagation in tissue of 1.5 mm per µs, one needs optical pulses shorter than 0.01 µs. Thus, utilization of short (nanosecond) optical pulses represents necessary (but not sufficient) condition to achieve desirable spatial (axial) resolution of OAT. The sufficient condition to obtain desirable spatial resolution is to employ detectors of acoustic waves with temporal response-function of not worse than the optical pulse duration. Satisfaction of irradiation conditions of temporal pressure confinement is also required for the optoacoustic signals to accurately resemble profiles of absorbed optical energy in tissue. Distribution of absorbed optical energy can be used to visualize and characterize quantitatively various tissue structures and their physiological functions based on variations in tissue optical properties. In order to relate tissue structure to optoacoustic images, the acoustic detectors must be capable of resolving not only rapid changes in optoacoustic signals associated with sharp edges and boundaries in tissues, but also reproduce slow changes associated with smooth variation in optical properties within one type of tissue. In other words, acoustic detectors have to detect both high and low ultrasonic frequencies of acoustic pressure at once. These types of acoustic detectors are called ultrawide-band acoustic transducers. These transducers have relatively equal detection sensitivity over the entire ultrasonic range from 20 kHz to 20 MHz (and in some cases even higher up to 100 MHz). The ultrasonic detection bandwidth of acoustic transducers defines the limits of axial (radial) resolution. The lateral resolution of an optoacoustic image, on the other hand, is defined by dimensions of each acoustic transducer, dimensions and geometry of the acoustic transducers in array. The array of transducers can be simulated by scanning a single transducer along tissue surface.  Thermoacoustic tomography is a more general term for optoacoustic tomography, as it encompasses light and all other forms of electromagnetic radiation (other examples include microwaves or radiowaves), which induce thermoelastic expansion of tissue and generation of ultrasound signals.
70.29.12.241 (talk) 05:51, 8 July 2009 (UTC)
thread_title: PI

message: After glancing at this article, I feel we need a bit of rewrite. Some of the verbiage (e.g. biomedical imaging modality) seems poor. Is this actually used for medical imaging today? I think it's still a lab technique, no? NickCT (talk) 17:48, 27 July 2015 (UTC)
thread_title:  biomedical imaging modality? 

message: Photoacoustic tomography seems to be a subset of Photoacoustic imaging, which is a much better developed article. Derek Andrews (talk) 13:14, 3 September 2015 (UTC)
thread_title:  Proposed merge with [[Photoacoustic tomography]] 

message: Many areas of the text refer to figures that are not present in the article.  — Preceding unsigned comment added by Pencilneck (talk • contribs) 19:10, 29 March 2016 (UTC)
replies: text: I think the figures were deleted for copyright violation. I removed the references in the text. - Pollux568 (talk) 18:52, 21 July 2016 (UTC)
thread_title:  Missing Figures

message: shows a video made with a new technique : single-impulse photoacoustic computed tomography (SIP-PACT) - or is it just a new name ? Should it be mentioned in this article somewhere ? - Rod57 (talk) 12:03, 24 May 2017 (UTC)
thread_title:  single-impulse photoacoustic computed tomography (SIP-PACT)