Abstract
BackgroundThe aim of this study was to evaluate the diagnostic utility of PAI at detecting thyroid microcalcifications at 700 nm laser wavelengths.MethodsThis study included 36 resected samples in 18 patients. To evaluate the PA manifestation of microcalcifications in PAI, gray level histogram and co-occurrence matrix (COM) texture parameters were extracted from the 3 fixed ROI US and PA images, respectively, per sample. We compared the textural parameters obtained from specimen PAIs between samples with punctate microcalcifications on specimen radiography and those without microcalcifications.ResultsOn specimen US, the mean value (2748.4±862.5) of samples with microcalcifications on specimen radiography was higher than that (1961.9±780.2) of those without microcalcifications (P = 0.007). However, there were no significant differences in textural parameters obtained from specimen PAIs between samples with punctate microcalcifications on specimen radiography and those without when applying both the mean value of the three slices of thyroid specimens and the value of the thyroid specimen slice which had the highest value of the mean values in specimen US.ConclusionPAI did not show significant PA contrast on thyroid microcalcifications indicating that the experimental setup and protocols should be enhanced, e.g., method of complete blood rejection from ex vivo specimens, the multi-wavelength spectroscopic PA imaging method which can solely extract the PA signal from microcalcifications even with high spectral interferences, or PA imaging with narrower slice thickness using 2-dimensional array transducer, etc.
Highlights
High-frequency ultrasonography (US) is a highly sensitive diagnostic tool that detects thyroid calcifications as well as thyroid nodules
Thyroid calcifications can only be seen through specimen radiography, there have been no preoperative clinical tools that detect thyroid calcifications like mammography does with breast calcifications until now [2]
Through previous ex vivo experiments, we have found that the optimal laser wavelength of Photoacoustic imaging (PAI) to detect breast microcalcifications which were not detected on US is in the 690–700 nm range [15]
Summary
High-frequency ultrasonography (US) is a highly sensitive diagnostic tool that detects thyroid calcifications as well as thyroid nodules. US has shown some drawbacks in the detection of thyroid microcalcifications which are related to thyroid malignancies [2]. Photoacoustic imaging (PAI) is a raising imaging modality that uses the different optical absorption properties of tissues and it provides high spatial and contrast resolutions [4,5]. Integrated US and PAI have been introduced in a variety of clinical fields such as diagnoses of ovarian cancer [10,11], breast cancer [12], and inflammatory joint diseases [13], and the detection of lipid deposits [14] and breast microcalcifications [15]. The aim of this study was to evaluate the diagnostic utility of PAI at detecting thyroid microcalcifications at 700 nm laser wavelengths
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
