Abstract-Methods for registering and calibrating in vivo terahertz images of cutaneous burn wounds

Priyamvada Tewari, James Garritano, Neha Bajwa, Shijun Sung, Haochong Huang, Dayong Wang, Warren Grundfest, Daniel B. Ennis, Dan Ruan, Elliott Brown, Erik Dutson, Michael C. Fishbein, and Zachary Taylor

Fig. 1 Burn zones organize as concentric like shells in the depth are hypothesized to appear as projections of the shells on the surface. Skin layers denoted A, B, C and damage zones denoted 1, 2, 3, 4. (a) Cross-sectional view: damage from superficial thickness wounds are limited primarily to the stratum corneum and epidermis, partial thickness burn wounds extend into the epidermis, and full thickness wounds extend into deep dermis. (b) Isometric view providing orientation between (a) and (c). (c) Top down view: The damage zones, and thus variations in surface TWC should present as regions concentric with the center.

https://www.osapublishing.org/boe/abstract.cfm?uri=boe-10-1-322

A method to register THz and visible images of cutaneous burn wounds and to calibrate THz image data is presented. Images of partial and full thickness burn wounds in 9 rats were collected over 435 mins. = 7.25 hours following burn induction. A two-step process was developed to reference the unknown structure of THz imaging contrast to the known structure and the features present in visible images of the injury. This process enabled the demarcation of a wound center for each THz image, independent of THz contrast. Threshold based segmentation enabled the automated identification of air (0% reflectivity), brass (100% reflectivity), and abdomen regions within the registered THz images. Pixel populations, defined by the segmentations, informed unsupervised image calibration and contrast warping for display. The registered images revealed that the largest variation in THz tissue reflectivity occurred superior to the contact region at ~0.13%/min. Conversely the contact region showed demonstrated an ~6.5-fold decrease at ~0.02%/min. Exploration of occlusion effects suggests that window contact may affect the measured edematous response.

© 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Abstract-Advances in biomedical imaging using THz technology with applications to burn-wound assessment

Priyamvada Tewari, Colin Kealey, Jun Sung, Zachary D. Taylor

https://www.researchgate.net/publication/258712377_Advances_in_biomedical_imaging_using_THz_technology_with_applications_to_burn-wound_assessment

Terahertz (THz) hydration sensing and image has been a topic of increased interest recently due largely to improvements in source and detector technology and the identification of applications where current hydration sensing techniques are insufficient. THz medical imaging is an expanding field of research and tissue hydration plays a key role in the contrast observed in THz tissue reflectance and absorbance maps. This paper outlines the most recent results in burn and corneal imaging where hydration maps were used to assess tissue status. A 3 day study was carried out in rat models where a THz imaging system was used to assess the severity and extent of burn throughout the first day of injury and at the 24, 48, and 72 hour time points. Marked difference in tissue reflectance were observed between the partial and full thickness burns and image features were identified that may be used as diagnostic markers for burn severity. Companion histological analysis performed on tissue excised on Day 3 confirms hypothesized burn severity. The results of these preliminary animal trials suggest that THz imaging may be useful in burn wound assessment where current clinical modalities have resolution and/or sensitivity insufficient for accurate diagnostics