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Multispectral Photoacoustic Imaging of Prostate Cancer: Preliminary Ex-vivo Results.

Dogra VS, Chinni BK, Valluru KS, Joseph JV, Ghazi A, Yao JL, Evans K, Messing EM, Rao NA - J Clin Imaging Sci (2013)

Bottom Line: A total of 30 patients undergoing prostatectomy for biopsy-confirmed prostate cancer were included in this study with informed consent.Sensitivity, specificity, positive predictive value, and negative predictive value of our imaging system were found to be 81.3%, 96.2%, 92.9% and 89.3% respectively.Our preliminary results of ex-vivo human prostate study suggest that multispectral PA imaging can differentiate between malignant prostate, BPH and normal prostate tissue.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Urology, and BME, University of Rochester, Rochester, NY 14642, USA.

ABSTRACT

Objective: The objective of this study is to validate if ex-vivo multispectral photoacoustic (PA) imaging can differentiate between malignant prostate tissue, benign prostatic hyperplasia (BPH), and normal human prostate tissue.

Materials and methods: Institutional Review Board's approval was obtained for this study. A total of 30 patients undergoing prostatectomy for biopsy-confirmed prostate cancer were included in this study with informed consent. Multispectral PA imaging was performed on surgically excised prostate tissue and chromophore images that represent optical absorption of deoxyhemoglobin (dHb), oxyhemoglobin (HbO2), lipid, and water were reconstructed. After the imaging procedure is completed, malignant prostate, BPH and normal prostate regions were marked by the genitourinary pathologist on histopathology slides and digital images of marked histopathology slides were obtained. The histopathology images were co-registered with chromophore images. Region of interest (ROI) corresponding to malignant prostate, BPH and normal prostate were defined on the chromophore images. Pixel values within each ROI were then averaged to determine mean intensities of dHb, HbO2, lipid, and water.

Results: Our preliminary results show that there is statistically significant difference in mean intensity of dHb (P < 0.0001) and lipid (P = 0.0251) between malignant prostate and normal prostate tissue. There was difference in mean intensity of dHb (P < 0.0001) between malignant prostate and BPH. Sensitivity, specificity, positive predictive value, and negative predictive value of our imaging system were found to be 81.3%, 96.2%, 92.9% and 89.3% respectively.

Conclusion: Our preliminary results of ex-vivo human prostate study suggest that multispectral PA imaging can differentiate between malignant prostate, BPH and normal prostate tissue.

No MeSH data available.


Related in: MedlinePlus

Multispectral photoacoustic (PA) imaging of prostate. PA images are acquired at multiple laser wavelengths. Each wavelength image is a composite image of all the tissue constituents such as deoxy-hemoglobin (dHb), oxy-hemoglobin (HbO2), lipid and water. Chromophore analysis was performed to extract PA images showing absorption of individual constituents from the multi-wavelength images. All the PA images are co-registered with histopathology and photograph of the gross specimen. (a) Photograph of gross prostate specimen (b) Histopathology of prostate with malignant region encircled. (c) Composite PA image acquired at 760 nm wavelength (d) Composite PA image acquired at 850 nm wavelength (e) PA image showing absorption of dHb (f) PA image showing absorption of HbO2. Higher absorption of dHb was seen in the region of interest corresponding to malignant prostate tissue compared to HbO2.
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Figure 7: Multispectral photoacoustic (PA) imaging of prostate. PA images are acquired at multiple laser wavelengths. Each wavelength image is a composite image of all the tissue constituents such as deoxy-hemoglobin (dHb), oxy-hemoglobin (HbO2), lipid and water. Chromophore analysis was performed to extract PA images showing absorption of individual constituents from the multi-wavelength images. All the PA images are co-registered with histopathology and photograph of the gross specimen. (a) Photograph of gross prostate specimen (b) Histopathology of prostate with malignant region encircled. (c) Composite PA image acquired at 760 nm wavelength (d) Composite PA image acquired at 850 nm wavelength (e) PA image showing absorption of dHb (f) PA image showing absorption of HbO2. Higher absorption of dHb was seen in the region of interest corresponding to malignant prostate tissue compared to HbO2.

Mentions: In this study, we have presented our preliminary findings with the EMPI device that was developed to characterize prostate tissue in the ex-vivo study. Our PA imaging experiments were able to provide information on tissue chromophores in ex-vivo prostate tissue suggesting that it may be useful for the diagnosis and prognosis of underlying prostate disease. Approximately, prostate cancers (0.64 mL/g/min) have three times more blood flow than normal prostate (0.21 mL/g/ min) and the oxygenation level (6 mmHg) much lower compared to normal prostate (26 mmHg).[15] Prostate tumors being hypoxic, our EMPI system results showed that dHb is one of the key constituents that can help us differentiate malignant from non-malignant prostate tissue [Figure 7]. PA imaging might help in the prognosis and follow-up of prostate disease based on its ability to monitor variations in concentrations of tissue constituents. PA imaging information is mainly derived from spectroscopic analysis. For an advanced imaging technology, PA imaging combined with ultrasound will be capable of visualizing both the functional and structural properties of a tissue. The development of this resulting non-invasive hybrid imaging technology will add features in differentiating malignant from benign and improve the quality of lives.


Multispectral Photoacoustic Imaging of Prostate Cancer: Preliminary Ex-vivo Results.

Dogra VS, Chinni BK, Valluru KS, Joseph JV, Ghazi A, Yao JL, Evans K, Messing EM, Rao NA - J Clin Imaging Sci (2013)

Multispectral photoacoustic (PA) imaging of prostate. PA images are acquired at multiple laser wavelengths. Each wavelength image is a composite image of all the tissue constituents such as deoxy-hemoglobin (dHb), oxy-hemoglobin (HbO2), lipid and water. Chromophore analysis was performed to extract PA images showing absorption of individual constituents from the multi-wavelength images. All the PA images are co-registered with histopathology and photograph of the gross specimen. (a) Photograph of gross prostate specimen (b) Histopathology of prostate with malignant region encircled. (c) Composite PA image acquired at 760 nm wavelength (d) Composite PA image acquired at 850 nm wavelength (e) PA image showing absorption of dHb (f) PA image showing absorption of HbO2. Higher absorption of dHb was seen in the region of interest corresponding to malignant prostate tissue compared to HbO2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3814905&req=5

Figure 7: Multispectral photoacoustic (PA) imaging of prostate. PA images are acquired at multiple laser wavelengths. Each wavelength image is a composite image of all the tissue constituents such as deoxy-hemoglobin (dHb), oxy-hemoglobin (HbO2), lipid and water. Chromophore analysis was performed to extract PA images showing absorption of individual constituents from the multi-wavelength images. All the PA images are co-registered with histopathology and photograph of the gross specimen. (a) Photograph of gross prostate specimen (b) Histopathology of prostate with malignant region encircled. (c) Composite PA image acquired at 760 nm wavelength (d) Composite PA image acquired at 850 nm wavelength (e) PA image showing absorption of dHb (f) PA image showing absorption of HbO2. Higher absorption of dHb was seen in the region of interest corresponding to malignant prostate tissue compared to HbO2.
Mentions: In this study, we have presented our preliminary findings with the EMPI device that was developed to characterize prostate tissue in the ex-vivo study. Our PA imaging experiments were able to provide information on tissue chromophores in ex-vivo prostate tissue suggesting that it may be useful for the diagnosis and prognosis of underlying prostate disease. Approximately, prostate cancers (0.64 mL/g/min) have three times more blood flow than normal prostate (0.21 mL/g/ min) and the oxygenation level (6 mmHg) much lower compared to normal prostate (26 mmHg).[15] Prostate tumors being hypoxic, our EMPI system results showed that dHb is one of the key constituents that can help us differentiate malignant from non-malignant prostate tissue [Figure 7]. PA imaging might help in the prognosis and follow-up of prostate disease based on its ability to monitor variations in concentrations of tissue constituents. PA imaging information is mainly derived from spectroscopic analysis. For an advanced imaging technology, PA imaging combined with ultrasound will be capable of visualizing both the functional and structural properties of a tissue. The development of this resulting non-invasive hybrid imaging technology will add features in differentiating malignant from benign and improve the quality of lives.

Bottom Line: A total of 30 patients undergoing prostatectomy for biopsy-confirmed prostate cancer were included in this study with informed consent.Sensitivity, specificity, positive predictive value, and negative predictive value of our imaging system were found to be 81.3%, 96.2%, 92.9% and 89.3% respectively.Our preliminary results of ex-vivo human prostate study suggest that multispectral PA imaging can differentiate between malignant prostate, BPH and normal prostate tissue.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Urology, and BME, University of Rochester, Rochester, NY 14642, USA.

ABSTRACT

Objective: The objective of this study is to validate if ex-vivo multispectral photoacoustic (PA) imaging can differentiate between malignant prostate tissue, benign prostatic hyperplasia (BPH), and normal human prostate tissue.

Materials and methods: Institutional Review Board's approval was obtained for this study. A total of 30 patients undergoing prostatectomy for biopsy-confirmed prostate cancer were included in this study with informed consent. Multispectral PA imaging was performed on surgically excised prostate tissue and chromophore images that represent optical absorption of deoxyhemoglobin (dHb), oxyhemoglobin (HbO2), lipid, and water were reconstructed. After the imaging procedure is completed, malignant prostate, BPH and normal prostate regions were marked by the genitourinary pathologist on histopathology slides and digital images of marked histopathology slides were obtained. The histopathology images were co-registered with chromophore images. Region of interest (ROI) corresponding to malignant prostate, BPH and normal prostate were defined on the chromophore images. Pixel values within each ROI were then averaged to determine mean intensities of dHb, HbO2, lipid, and water.

Results: Our preliminary results show that there is statistically significant difference in mean intensity of dHb (P < 0.0001) and lipid (P = 0.0251) between malignant prostate and normal prostate tissue. There was difference in mean intensity of dHb (P < 0.0001) between malignant prostate and BPH. Sensitivity, specificity, positive predictive value, and negative predictive value of our imaging system were found to be 81.3%, 96.2%, 92.9% and 89.3% respectively.

Conclusion: Our preliminary results of ex-vivo human prostate study suggest that multispectral PA imaging can differentiate between malignant prostate, BPH and normal prostate tissue.

No MeSH data available.


Related in: MedlinePlus