Biomedical subjects

Pei-Lin Hsiung

Publications and source records attributed to Pei-Lin Hsiung.

4 recordsLinked to original sources

PubMed2005

Ultrahigh-resolution and 3-dimensional optical coherence tomography ex vivo imaging of the large and small intestines.

BACKGROUND: Ultrahigh-resolution optical coherence tomography (OCT) has an axial resolution of <5 microm, 2 to 3 times finer than standard OCT. This study investigates ultrahigh-resolution and three-dimensional OCT for ex vivo imaging of the large and small intestines and correlates images with histology. METHODS: Ultrahigh-resolution OCT imaging was performed on fresh surgical specimens from the large and small intestines in the pathology laboratory, and images were correlated with histology. OCT was performed at 1.3-microm wavelength with 4.5-microm axial x 11-microm transverse resolution and at 1.1-microm wavelength with 3.5-microm axial x 6-microm transverse resolution. Three-dimensional OCT also was investigated. RESULTS: Normal and pathologic areas from 23 surgical specimens of the large and small intestines were imaged. Ultrahigh-resolution OCT distinguished the epithelial layer of the mucosa and visualized individual villi, glands, and crypts. Finer transverse resolutions improved visualization of features, e.g., the epithelium, but reduced the depth of field. Architectural distortion of glands from inflammatory and neoplastic processes was observed. Three-dimensional rendering enabled visualization of surface pit pattern and mucosal folds as well as subsurface crypt microstructure. CONCLUSIONS: This study evaluates new OCT technology and can provide a baseline for interpreting future ultrahigh-resolution endoscopic OCT studies.

Adult↗

PubMed2004

High-resolution imaging of the thyroid gland using optical coherence tomography.

BACKGROUND: Current diagnostic imaging modalities of the thyroid gland cannot reliably distinguish benign from malignant lesions, primarily because of their inability to visualize microscopic structure. A high-resolution imaging technique capable of examining thyroid tissue architectural morphology in real time is needed. Optical coherence tomography (OCT) has been shown to achieve high resolutions approaching the cellular range (1-15 microm). The feasibility of optical coherence tomography for imaging thyroid tissue was explored ex vivo on the human thyroid gland. METHODS: High-resolution OCT was performed in real time at 2 to 4 frames per second on three postmortem and 15 surgically excised thyroid glands containing normal, hyperplastic, and neoplastic tissue. OCT images acquired were compared with those obtained using standard histopathologic methods. RESULTS: The microstructure of the normal thyroid gland, including colloid-filled follicles as small as 15 microm and their supporting stroma, was clearly identified. OCT images of degenerative, hyperplastic, adenomatous, and malignant change within the thyroid gland were shown to correlate well with corresponding histopathologic findings. CONCLUSIONS: The ability of OCT to image thyroid tissue microarchitecture makes it a potentially powerful technology that can be used to assess the thyroid gland at a resolution greater than currently available clinical imaging modalities.

Adult↗

PubMed2003

High-speed path-length scanning with a multiple-pass cavity delay line.

Techniques for high-speed delay scanning are important for low-coherence interferometry, optical coherence tomography, pump probe measurements, and other applications. We demonstrate a novel scanning delay line using a multiple-pass cavity. Differential delays are accumulated with each pass so that millimeter delays can be generated with tens of micrometer mirror displacements. With special design criteria, misalignment sensitivity can be dramatically reduced. The system is demonstrated to scan 6 m/s at 2-kHz repetition rates. Real-time optical coherence tomography imaging with 500 pixel images at four frames/s is performed. Using a Cr:forsterite laser source, we obtained axial image resolutions of 6 microm with 92-dB sensitivity.

Models, Theoretical↗

PubMedDate not supplied

Effect of tissue preservation on imaging using ultrahigh resolution optical coherence tomography.

Ultrahigh resolution optical coherence tomography (OCT) is an emerging imaging modality that enables noninvasive imaging of tissue with 1- to 3-microm resolutions. Initial OCT studies have typically been performed using harvested tissue specimens (ex vivo). No reports have investigated postexcision tissue degradation on OCT image quality. We investigate the effects of formalin fixation and commonly used cell culture media on tissue optical scattering characteristics in OCT images at different times postexcision compared to in vivo conditions. OCT imaging at 800-nm wavelength with 1.5-mum axial resolution is used to image the hamster cheek pouch in vivo, followed by excision and imaging during preservation in phosphate-buffered saline (PBS), Dulbecco's Modified Eagle's Media (DMEM), and 10% neutral-buffered formalin. Imaging is performed in vivo and at sequential time points postexcision from 15 min to 10 to 18 h. Formalin fixation results in increases in scattering intensity from the muscle layers, as well as shrinkage of the epithelium, muscle, and connective tissue of approximately 50%. PBS preservation shows loss of optical contrast within two hours, occurring predominantly in deep muscle and connective tissue. DMEM maintains tissue structure and optical scattering characteristics close to in vivo conditions up to 4 to 6 h after excision and best preserved tissue optical properties when compared to in vivo imaging.

Animals↗