Comparison of textural parameters obtained from specimen photoacoustic images between tissues with psammoma bodies on pathology and those without when applying the mean value of the three slices of thyroid specimens.

<p>*Std, standard deviation.</p>†<p>Level, number of level.</p>‡<p>Distance, co-occurrence distance (pixel).</p>§<p>Orthogonal and diagonal, co-occurrence direction with ± (1,0) and ± (1,1), respectively.</p><p>Comparison of textural parameters obtained from specimen photoacoustic images between tissues with psammoma bodies on pathology and those without when applying the mean value of the three slices of thyroid specimens.</p

Comparison of textural parameters obtained from specimen photoacoustic images between tissues with punctate microcalcifications on specimen radiology and those without when applying the value of a thyroid specimen slice which has the highest value of the mean values in the specimen ultrasound.

<p>*Std, standard deviation.</p>†<p>Level, number of level.</p>‡<p>Distance, co-occurrence distance (pixel).</p>§<p>Orthogonal and diagonal, co-occurrence direction with ± (1,0) and ± (1,1), respectively.</p><p>Comparison of textural parameters obtained from specimen photoacoustic images between tissues with punctate microcalcifications on specimen radiology and those without when applying the value of a thyroid specimen slice which has the highest value of the mean values in the specimen ultrasound.</p

A 43-year-old male underwent total thyroidectomy due to thyroid cancer.

<p>A specimen radiograph (a) showed a mass with diffuse punctate calcifications in the left thyroid gland and no discernable calcifications in the right thyroid gland. To verify calcifications on photoacoustic imaging, two thyroid tissues from different lobes were obtained from thyroid specimens, with tissue from the left lobe containing compact punctate calcifications and tissue from the right lobe not containing any calcifications (two square boxes). The tissues were retrieved from the specimen without disturbing pathologic diagnosis. A specimen radiograph (b) showed punctate microcalcifications (arrows) acquired from the left thyroid gland and no calcifications acquired from the right thyroid gland. The texture analysis was conducted for the selected region-of-interests (ROIs) indicated by the white boxes in PA images (c) at 700-nm lasing wavelength. Note that the clustered hyperreactive PA signals suspected from the blood coagulations (white arrows) were excluded in the texture analysis, which can also be found on the corresponding photographs (d). In visual assessment of PA image, the ROI of the right resected tissue with microcalcifications contains more PA signals than that of the left resected tissue without microcalcifications. Although the mean value of samples from the left thyroid gland was higher than that of those from the right thyroid gland on specimen US, the mean value of samples from the right thyroid gland was higher than that of the left thyroid gland on both photoacoustic images. There were psammoma bodies from a left resected tissue and no psammoma bodies (arrows) (H&E; X100) from a right resected tissue on pathology (e).</p

System configuration for the <i>ex vivo</i> experiments with a 1-dimensional photoacoustic/ultrasound combined probe.

<p>Note that the FB stands for the optical fiber bundle which delivers the laser energy to the thyroid specimen and the <i>x</i>, <i>y</i>, and <i>z</i> direction indicate the elevation, lateral, and axial direction from the PA/US combined probe, respectively.</p

A 46-year-old male underwent total thyroidectomy due to thyroid cancer.

<p>A specimen radiograph (a) showed a mass with calcifications in the upper and mid pole of the right thyroid gland and punctate microcalcifications in the lower pole of the right thyroid gland which were not seen on US. There were no discernible calcifications in the left thyroid gland. To verify calcifications on PAI, two thyroid tissues from different lobes were obtained from thyroid specimens, with tissue from the right lobe containing compact punctate calcifications and tissue from the left lobe not containing any calcifications (two square boxes). The tissues were retrieved from the thyroid specimen without disturbing pathologic diagnosis. A specimen radiograph (b) showed punctate microcalcifications (arrows) acquired from the right thyroid gland and no calcifications acquired from the left thyroid gland. The texture analysis was conducted for the selected region-of-interests (ROIs) indicated by the white boxes in PA images (c) at 700-nm lasing wavelength. Note that the clustered hyperreactive PA signals suspected from the blood coagulations (white arrows) were excluded in the texture analysis, which can also be found on the corresponding photographs (d). In visual assessment, the ROI of the right resected tissue with microcalcifications contains more PA signals than that of the left resected tissue without microcalcifications. Correspondingly, the mean values of both US and PA images calculated from the right thyroid gland were higher than that from the left thyroid gland. There were psammoma bodies from a right resected tissue and no psammoma bodies (arrows) (H&E; X100) from a left resected tissue on pathology (e).</p

Diagram demonstrates experimental arrangement (A) to acquire photoacoustic signal images from 8-gauge core-biopsied breast specimens (B).

<p>To obtain 3-dimensional photoacoustic data, the probe was mechanically moved along the frame scanning direction (B).</p

Representative case from ex vivo experiments with core specimens of breast tissue included in the microcalcification group (case #2).

<p>Specimen mammography (A) and photoacoustic images obtained from both 700 nm (B) and 800 nm (C) wavelengths were reconstructed with comparable configurations in both directions (top-down and lateral views). The locations of photoacoustic signals were well matched with microcalcifications observed in specimen mammography. The photoacoustic image at 800 nm (C) showed decreasing photoacoustic signal intensities in the region confirmed as microcalcifications through specimen mammography compared with the photoacoustic image at 700 nm (B). The mean value of PAI ratio^† from region of interest was 2.80. Abbreviations: PAI ratio, calculated ratio of the amplitude occurring at the 700 nm wavelength section to that occurring at the 800 nm wavelength section.</p

Multiple regression analysis in the microcalcification group (n = 11) to find factors that contribute to PAI ratios.

<p>*Malignant result according to the pathology report.</p>†<p>Median value of calcification-foci in the core.</p><p>Abbreviations: PAI ratio, calculated ratio of the amplitude occurring at the 700 nm wavelength section to that occurring at the 800 nm wavelength section.</p

Change in mean values of the maximum photoacoustic signals at the 700 nm and 800 nm wavelength sections in the control and microcalcification group.

<p>Change in mean values of the maximum photoacoustic signals at the 700 nm and 800 nm wavelength sections in the control and microcalcification group.</p

Results of blind review to assume calcification on PAI.

<p>Abbreviations: PAI, photoacoustic Imaging.</p