Burn depths evaluation based on active dynamic IR thermal imaging—A preliminary study
Introduction
The modern approach to skin burn depth assessment tries to resolve the problem of healing and the appropriate choice of treatment—conservative or surgical [1], [2]. The traditional approach distinguishes the following grades of burn wound: I, superficial; IIa, superficial dermal; IIb, deep dermal; and III, full thickness of the skin [3]. In clinical practice even the inexperienced doctor has no difficulty in classifying first and third degree burns correctly. However, differentiation between the IIa (superficial dermal) and IIb (deep dermal) classes of wound is problematic. Clinical evaluation, mainly based on visual inspection, only insures an accurate prognosis in 50–70% of these cases [2], [3], [4], [5]. A method that enables burn wound depth to be correctly assessed and the choice of treatment to be made properly is, therefore, of the greatest importance. The aim of this paper is to present one such new objective method. The method based on IR thermal imaging of transient processes allows quantitative evaluation of burn depth and provides the answer to one of the most important questions in burn diagnostics: Will the burn heal spontaneously within 3 weeks of the burn or not?
The reference method in burn depth evaluation is histopathological assessment but as this is invasive, local and time consuming, it is not frequently used [6], [7]. Research interests have concentrated on the search for non-invasive, objective and quantitative diagnostic methods. Static thermography (ST) [8], [9], [10], ultrasonography (USG) [11], [12], spectrophotometry [13], [14], laser Doppler imaging (LDI) [15], [16], [17], [18] and indocyanine green fluorescence (ICG) [19], [20] are those most frequently cited, although none has been broadly accepted as a solution for clinical applications [2], [5].
Recently we discussed the diagnostic value of ST [21], where the basic figure of merit—ΔT, namely the difference between the mean values of skin temperature for the burn wound area and the unaffected reference skin area, is defined. The inconveniences of the method are the need for meticulous care about measurement conditions and the lack of commonly accepted temperature ranges of ΔT for particular burn wound depth classifications. However, a great advantage of the method is its non-invasive character, the possibility of assessing relatively large burn areas and the easy and objective capture of images for medical documentation [22], [23].
We propose an IR thermal imaging modality new to medical diagnostic applications, active dynamic IR thermal imaging (ADT), also termed active dynamic thermography. This is a method based on infrared detection which uses the cameras already applied in static thermography but which shows thermal tissue properties instead of changes in temperature distribution. Such an approach eliminates several of the drawbacks of traditional thermography while preserving the positive features and allowing quantitative objective assessment of burns.
Section snippets
Active dynamic IR thermal imaging (ADT)
The concept of infrared non-destructive testing (IR/NDT) has been known in industry for several years [24]. ADT may be regarded as an advanced version of IR/NDT. Analysis of heat transfer enables thermophysical material properties, such as thermal diffusivity or conductivity, to be quantified. Knowledge of these two thermal parameters allows the subsurface structure to be determined.
The general concept of the measurements performed in ADT is shown in Fig. 1. First the steady state temperature
Results
Groups of wounds were distinguished post hoc: those shallower than 60% of the dtms, which healed within 3 weeks (18 cases); and those deeper than 60% of the dtms, unhealed (five cases) (Fig. 4).
For ADT the mean value of the thermal time constant for burns shallower than 60% of the dtms (those healing within 3 weeks) was τ = 12.08 ± 1.94 s and for deeper ones (“non-healing”) it was τ = 9.07 ± 0.68 s. The difference was at the statistically significant level, (p < 0.05). We found that parameter τ had a
Discussion
We started working on model-based ADT applications in medical diagnostics in 1999 [31] and since then have published further data on the procedures applied to burn evaluation, for example in 2001 [32], [33]. Prior to these publications thermography was applied in burn depth assessment only in the traditional static form, listing only the most important positions [8], [9], [10], [22], [34], [35], [36]. Only Dickey et al. [37] made the attempt to propose an in vitro burn model using biosynthetic
Conclusions
- 1.
ADT examination is simple, non-contact and short. The instrumentation to be applied is based on the IR-cameras already used in hospitals and now available at reduced prices.
- 2.
The procedure is not as sensitive to external conditions as static thermography (ST). However, the standards valid for ST should be secured.
- 3.
The results of the ADT and histopathological evaluations are fully in agreement. This should not be regarded as the general rule, as the evaluation of the method was made ex post and in
References (45)
Looking at burn wounds: the A.B. Wallace Memorial Lecture 1991
Burns
(1992)- et al.
Burn depth and its histological measurement
Burns
(2001) - et al.
Thermographic assessment of hand burns
Burns
(1990) - et al.
Timing of the thermographic assessment of burns
Burns
(1996) - et al.
Perfusion of burn wound assessed by laser Doppler imaging is related to burn depth and healing time
Burns
(2001) - et al.
An audit of the use of laser Doppler imaging (LDI) in the assessment of burns of intermediate depth
Burns
(2001) - et al.
Diagnosis of burn depth using laser-induced Indocyanine green fluorescence: a preliminary clinical trial
Burns
(2001) - et al.
Static thermography revisited—an adjunct method for determining the depth of the burn injury
Burns
(2005) The use of thermography in the assessment of burn and blood supply of flaps, with preliminary reports on its use in Dupuytren's contracture and treatment of varicose ulcers
Br J Plast Surg
(1974)- et al.
Thermographic assessment of burns using nonpermeable membrane as wound covering
Burns
(1991)
The evaporative water loss from burns and the water vapour permeability of grafts and artificial membranes used in the treatment of burns
Burns
Measurement of the thermal properties of human skin: a review
J Invest Dermatol
Early excision and grafting vs. nonoperative treatment of burns of indeterminate depth: a randomised prospective study
J Trauma
Burn depth: a review
World J Surg
An anatomic classification of burns
Ann Surg
The diagnosis of the depth of burning
Br J Surg
Standardized burn model using a multiparametric histologic analysis of burn depth
Acad Emerg Med
A practical technique for the thermographic estimation of burn depth: a preliminary report
Burns
Determination of burn depth with noncontact ultrasonography
J Burn Care Rehab
The use of high frequency ultrasonography in the prediction of burn depth
J Burn Care Rehab
Multispectral imaging of burn wounds: a new clinical instrument for evaluating burn depth
IEEE Trans Biomed Eng
Reflection–optical multispectral imaging method for objective determination of burn depth
Burns
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