Ali Sepehr

In vivo three-dimensional spectral domain endoscopic optical coherence tomography using a microelectromechanical system mirror

A biopsy is a well-known medical test used to evaluate tissue abnormality. Biopsy specimens are invasively taken from part of a lesion and visualized by microscope after chemical treatment. However, diagnosis by means of biopsy is not only variable due to depth and location of specimen but may also damage the specimen. In addition, only a limited number of specimens can be obtained, thus, the entire tissue morphology cannot be observed. We introduce a three-dimensional (3-D) endoscopic optical biopsy via optical coherence tomography employing a dual-axis microelectromechanical system scanning mirror. Since this technique provides high-resolution, noninvasive, direct, and multiple visualization of tissue, it could function as a clinical biopsy with advanced performance. The device was integrated with a conventional endoscope and utilized to generate in vivo 3-D clinical images in humans and animals.

Imaging the Human Tympanic Membrane Using Optical Coherence Tomography In Vivo

Objective: Optical coherence tomography (OCT) is a diagnostic imaging modality that combines low coherence light with interferometry to produce high-resolution cross-sectional images of living tissues. Using this technology, we have imaged in vivo the human tympanic membrane (TM) in the office clinic setting and characterized TM microstructure in normal and pathologic conditions. Study Design: Prospective clinical trial. Materials and Methods: The normal and diseased TMs in 10 adult subjects were examined. Each subject underwent direct microscopic examination before OCT imaging to provide visual coregistration of associated subsites including the anulus fibrosus, pars tensa, pars flaccida, and umbo. The probe from the imaging system (1,310-nm central wavelength, 15-&mgr;m coherence length, Niris; Imalux, Cleveland, OH, USA) was introduced into the ear canal to obtain lateral cross-sectional images. Results: Systematic imaging of the TM was performed with characterization of the epithelial and collagenous layers. The overall TM thickness was clearly demonstrated and quantified. Conclusion: The ability to noninvasively study middle ear microstructures in vivo is essential in the treatment of diseases of the ear. OCT may provide the otologist/neurotologist with the ability to 1) image pathology such as cholesteatoma, dimeric TMs, and chronic otitis media; 2) gauge the response to pharmacological therapy; and 3) monitor postsurgical changes after tympanoplasty and other procedures. OCT may provide a means to optimize the diagnosis and management of patients with middle ear disease.

Optical Coherence Tomography of the Cochlea in the Porcine Model

Objectives/Hypothesis: To demonstrate the feasibility of optical coherence tomography in microstructural imaging of the porcine cochlea.

Optical coherence tomography of the larynx in the awake patient

Objective To demonstrate the feasibility of performing optical coherence tomography of the human larynx on the awake patient with a novel flexible fiberoptic delivery system. Study Design Prospective clinical trial. Subjects and Methods Imaging was performed in 17 awake patients. A flexible optical coherence tomography probe was inserted through the nose and placed in near or gentle contact with laryngeal tissues under direct endoscopic visualization. Results Images were successfully obtained from all laryngeal subsites and clearly identified laryngeal mucosal microanatomy. Several critical probe design modifications improved rotational and angular control of the distal tip while allowing linear translation of the probe and allowing more accurate apposition of the probe onto target tissues, which is critical for transnasal laryngeal imaging. Conclusion This study demonstrates the feasibility of awake transnasal laryngeal optical coherence tomography and identifies key instrumentation needed to obtain useful images.

Anthropometric and aesthetic analysis of the Indian American woman's face☆

BACKGROUND This is the first study defining the facial anthropometric and aesthetic measurements in Indian American women (IAW). METHODS This is a prospective cohort study involving evaluation of facial photographs. Frontal, lateral and basal photographs were taken of IAW (n=102), and 30 anthropometric measurements were determined. Proportions were compared with published North American white women (NAWW) norms. Judges (n=6) evaluated the photographs for aesthetics using a visual analogue scale. Attractive IAW (top 15%) were compared with average IAW (remaining 85%) and average NAWW. All completed a facial self-esteem survey. RESULTS There were significant differences between IAW and NAWW in 25 of 30 facial measurements. Six measurements correlated with aesthetic scores: intercanthal distance, mouth width, nasolabial angle, midface height 2, ear length and nasal height. Attractive IAW had nine measurements approximating NAWW features, 15 measurements similar to average IAW values and two measurements distinct from both average IAW and average NAWW. Attractive IAW had higher facial self-esteem scores than average IAW. CONCLUSIONS Facial measurements in IAW are much different from NAWW, and these results will assist in preoperative planning. Several features are correlated with attractiveness in IAW: larger and wider-set eyes, a smaller midface, a smaller nose with greater tip rotation, smaller ears and a larger mouth. Attractive IAW display many measurements typical of average IAW and several measurements that reflect average NAWW values. These results contribute to concepts of transcultural aesthetics--for a minority ethnic group, facial beauty appears to be an assimilation of deep-rooted ethnic features with prevailing cultural traits and aesthetic standards.

Antibiotics in head and neck surgery in the setting of malnutrition, tracheotomy, and diabetes.

The objectives of this study are to compare short vs. long antibiotic prophylaxis in the setting of malnutrition, diabetes, and tracheotomy.

Aspiration of a capsule endoscope and description of a unique retrieval technique

The capsule endoscope has revolutionized small-bowel inspection, which before was limited to indirect studies, such as barium radiography, scintigraphy, and angiography, or to direct but invasive push enteroscopy. It provides a direct, yet minimally invasive, visualization of the small bowel. Capsule endoscopy is approved by the FDA for detection of small-bowel mucosal abnormalities. To date its major application has been evaluation of occult gastrointestinal (GI) bleeding. The device has been used in 340,000 patients worldwide, with 105,000 procedures in the US within the last year. As its applications increase to include evaluation of conditions such as Crohn’s disease, small-bowel polyps, and abnormal small-bowel radiographic studies, its utilization will increase (sales increased by 18% over the last year), and clinicians should be aware of its complications. Three cases of capsule endoscope aspiration have been reported in gastroenterology literature to date. This is the first report in otolaryngology literature. Although rare, this complication is potentially fatal and should be considered an emergency. A 67-year-old man with history of anemia was referred for capsule endoscopy to evaluate for occult GI hemorrhage. Due to a past medical history of hypertension, diabetes mellitus, cerebrovascular accident, and intermittent dysphagia, endoscopic placement of a capsule endoscope (M2A, Given Imaging, Ltd, Duluth, GA) was recommended. However, the patient declined and chose to swallow the capsule, immediately after which he began to cough and exhibit dysphonia, which resolved. There was no respiratory distress, but he developed a persistent cough. Within 3 minutes the patient became tachypneic and tachycardic, but his oxygen saturation remained above 95%. There were ronchi, but no stridor. The physician recognized the possibility of interrogating the capsule endoscope to determine its location. Images from the capsule endoscope were downloaded and analyzed within 5 minutes and definitively revealed that the device was aspirated promptly after it was swallowed (Fig 1). This process took less time than obtaining plain radiographs. The patient was taken to the operating room for retrieval

Gradient-index lens rod based probe for office-based optical coherence tomography of the human larynx.

Optical coherence tomography (OCT) is an evolving noninvasive imaging modality that has been used to image the human larynx during surgical endoscopy. The design of a long gradient-index lens-based probe capable of capturing images of the human larynx by use of spectral domain OCT during a typical office-based laryngoscopy examination is presented. An optical-ballast-based 4f optical relay system is proposed to realize variable working distance with a constant optical delay. In-vivo OCT imaging of the human larynx is demonstrated. Office-based OCT is a promising imaging modality for early laryngeal cancer diagnosis.

High-speed three-dimensional endoscopic OCT using MEMS technology

We present a three-dimensional (3-D) endoscopic OCT system based on a dual axis scanning microelectromechanical system (MEMS) mirror.

09:20: In-Situ OCT Imaging of Porcine Cochlear Microanatomy

The authors tested the hypothesis that regenerative capacity might inversely correlate with the thickness of the cortical actin bands in these epithelia. METHODS: Embryonic, neonatal, and adult Swiss Webster mice and White Leghorn chickens were anesthetized with CO2, decapitated, and their right ears were fixed in 3% glutaraldehyde in 0.15M cacodylate buffer, processed, and examined by Transmission Electron Microscopy (TEM). Their left ears were fixed in 4% paraformaldehyde in 0.15M PB and the left utricles were dissected and stained with AlexaFlour 488 phalloidin to label filamentous actin (F-actin). Widths of the circumferential cortical F-actin bands were measured at the full-width half-maximum of the intensity profile curves from Laser Scanning Confocal Microscopy (LSCM) images. RESULTS: LSCM and TEM analyses showed that the cortical F-actin bands in the maturing mouse utricle increase in width from embryonic ages until a sustained maximum by P12, whereas their counterparts in chicken utricles remain narrow even in adults. CONCLUSION: Relative thickness of the cortical F-actin bands in the utricular sensory neuroepithelia of chickens and mice correlate with the persistence of regeneration in chickens and the age-dependent decrease in regenerative capacity in mice. SIGNIFICANCE: The cortical F-actin band may play a major role in limiting hair cell regeneration in mammals. SUPPORT: NIH grant 5R01DC200 for studying hair cell regeneration.