title: Lock-in thermal imaging for the early-stage detection of cutaneous melanoma: a feasibility study.
abstract: This paper theoretically evaluates lock-in thermal imaging for the early-stage detection of cutaneous melanoma. Lock-in thermal imaging is based on the periodic thermal excitation of the specimen under test. Resulting surface temperature oscillations are recorded with an infrared camera and allow the detection of variations of the sample's thermophysical properties under the surface. In this paper, the steady-state and transient skin surface temperatures are numerically derived for a different stage of development of the melanoma lesion using a two-dimensional axisymmetric multilayer heat-transfer model. The transient skin surface temperature signals are demodulated according to the digital lock-in principle to compute both a phase and an amplitude image of the lesions. The phase image can be advantageously used to accurately detect cutaneous melanoma at an early stage of development while the maximal phase shift can give precious information about the lesion invasion depth. The ability of lock-in thermal imaging to suppress disturbing subcutaneous thermal signals is demonstrated. The method is compared with the previously proposed pulse-based approaches, and the influence of the modulation frequency is further discussed.
authors: Institute of Computational Physics, Zurich University of Applied Sciences, Technikumstrasse 9, 8401 Winterthur, Switzerland. Electronic address: mathias.bonmarin@zhaw.ch.
authors: Mathias
authors: M
authors: Bonmarin
authors: Dermatological Clinic, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, 1211 Geneva, Switzerland.
authors: Frédérique-Anne
authors: FA
authors: Le Gal
mesh_terms: D055088:Early Detection of Cancer / Q000379:methods*; D005240:Feasibility Studies; D006801:Humans; D008545:Melanoma / Q000175:diagnosis / Q000473:pathology; D008954:Models, Biological; D012878:Skin Neoplasms / Q000175:diagnosis / Q000473:pathology; D012881:Skin Temperature; D013816:Thermodynamics; D013817:Thermography / Q000379:methods*; D000096142:Cutaneous Malignant Melanoma
keywords: Bio-heat; Biological system modelling; Medical diagnostic imaging; Thermal imaging