Photoacoustic computed tomography correcting for heterogeneity and attenuation

Huang, Chao; Nie, Liming; Schoonover, Robert W.; Wang, Lihong V.; Anastasio, Mark A.

doi:10.1117/1.jbo.17.6.061211

Cited by 76 publications

(49 citation statements)

References 24 publications

(30 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Image quality can further be improved by use of advanced reconstruction algorithms that account for the presence of the skull, such as time-reversal methods. 8, 16 …”

Section: Resultsmentioning

confidence: 99%

Photoacoustic tomography through a whole adult human skull with a photon recycler

et al. 2012

Self Cite

View full text Add to dashboard Cite

Abstract. Photoacoustic tomography (PAT) of the human brain is challenging due to the fact that the skull strongly absorbs and scatters light, and attenuates and distorts ultrasound as well. For the first time, we demonstrated the feasibility of PAT through a whole adult human skull. A photon recycler (PR) was built to increase light transmittance through the skull. Both a graphite target and a canine brain were imaged through the skull. Use of the PR was found to improve the photoacoustic signal-to-noise ratio by a factor of 2.4. In addition, subtraction of photoacoustic signals that arise from light absorption within the skull significantly improved the contrast of the target. Our results indicate that PAT can potentially be applied to in vivo human brain imaging.

show abstract

“…Image quality can further be improved by use of advanced reconstruction algorithms that account for the presence of the skull, such as time-reversal methods. 8, 16 …”

Section: Resultsmentioning

confidence: 99%

Photoacoustic tomography through a whole adult human skull with a photon recycler

et al. 2012

Self Cite

View full text Add to dashboard Cite

show abstract

“…On the other hand, attenuation compensation using time reversal allows the absorption coefficient to be spatially varying, which is not possible with time-variant filtering. 45 This may be important for strongly heterogeneous media, for example, photoacoustic imaging of the brain, where the generated waves must also travel through the skull, 57 or if the detectors are connected to the sample via a coupling medium such as water with different acoustic properties.…”

Section: Application To Experimental Datamentioning

confidence: 99%

“…42 Huang et al has also illustrated the applicability of this scheme to media with a heterogeneous distribution of acoustic absorption values. 45 This was demonstrated through a series of phantom measurements with pencil leads embedded in an agar phantom enclosed by an acrylic shell. The restriction of this approach to attenuation compensation is that time reversal must be used to reconstruct the image.…”

mentioning

confidence: 99%

Acoustic attenuation compensation in photoacoustic tomography using time-variant filtering

Treeby

2013

J. Biomed. Opt

View full text Add to dashboard Cite

Abstract. Most reconstruction algorithms used in photoacoustic tomography do not account for the effects of acoustic attenuation on the recorded signals. For experimental measurements made in biological tissue, the frequency dependent acoustic attenuation causes high frequency components of the propagating photoacoustic waves to be significantly reduced. This signal loss manifests as a depth dependent magnitude error and blurring of features within the reconstructed image. Here, a general method for compensating for this attenuation using time-variant filtering is presented. The time-variant filter is constructed to correct for acoustic attenuation and dispersion following a frequency power law under the assumption the distribution of attenuation parameters is homogeneous. The filter is then applied directly to the recorded time-domain signals using a form of nonstationary convolution. Regularization is achieved using a time-variant window where the cutoff frequency is based on the local timefrequency distribution of the recorded signals. The approach is computationally efficient and can be used in combination with any detector geometry or reconstruction algorithm. Numerical and experimental examples are presented to illustrate the utility of the technique. Clear improvements in the magnitude and resolution of reconstructed photoacoustic images are seen when acoustic attenuation compensation is applied.

show abstract

“…The passive element technique also allows, besides SOS mapping, recovering the acoustic attenuation inside the object, 18 and this information will be used to correct for PA imaging, especially in highly attenuating media. 23 For higher temperatures in excess of 55°C, protein coagulation will also occur, which may have complex effects on the SOS making the estimation of temperature by our method inaccurate. For use of the method in this situation, the relationship between SOS and temperature during coagulation should be investigated.…”

Section: Discussionmentioning

confidence: 99%

Two-dimensional spatiotemporal monitoring of temperature in photothermal therapy using hybrid photoacoustic–ultrasound transmission tomography

Daoudi¹,

Es²,

Manohar³

et al. 2013

J. Biomed. Opt

View full text Add to dashboard Cite

Abstract. Recently, we presented an add-on to a photoacoustic (PA) computed tomography imager that permits the simultaneous imaging of ultrasound (US) transmission parameters such as the speed of sound (SOS), without additional measurements or instruments. This method uses strong absorbers positioned outside the object in the path of light for producing laser-induced US to interrogate the object in a conventional PA imager. Here, we investigate the feasibility of using this approach, first with PA to pin-point the location of photothermal therapeutic agents and then with serial SOS tomograms to image and monitor the resulting local temperature changes when the agents are excited with continuous wave (CW) light. As the object we used an agar-based tissue-mimicking cylinder carrying beads embedded with different concentrations of gold nanospheres. PA and SOS tomograms were simultaneously acquired as the gold nanospheres were photothermally heated using a 532-nm CW laser. In a first approximation, using the relation between SOS of water and temperature, the SOS tomograms were converted into temperature maps. The experimental results were verified using simulations: Monte Carlo modeling of light propagation through a turbid medium and using the obtained absorbed energy densities in heat diffusion modeling for spatial temperature distribution.

show abstract

Photoacoustic computed tomography correcting for heterogeneity and attenuation

Cited by 76 publications

References 24 publications

Photoacoustic tomography through a whole adult human skull with a photon recycler

Photoacoustic tomography through a whole adult human skull with a photon recycler

Acoustic attenuation compensation in photoacoustic tomography using time-variant filtering

Two-dimensional spatiotemporal monitoring of temperature in photothermal therapy using hybrid photoacoustic–ultrasound transmission tomography

Contact Info

Product

Resources

About