t has long been recognized that 1 of the most difficult assessments of the efficacy of wound healing materials is the measurement of decreasing volume of the healing wound over time. Some interactive wound management materials, such as vapor-permeable films, incorporate measuring grids within their presentation to aid qualitative evaluation of the rate of wound healing. These measurements, however, can give only superficial information and cannot relate to the diminishing volume of the wound as the healing process proceeds. In-vivo monitoring of wound healing has often been limited to either the external appearance of the wound or to histological examination of excised tissue samples. Neither of these approaches is ideal, as the former relies on subjective interpretations of the macroscopic appearance of the wound, and the latter involves the collection of biopsy material, which leads to the production of a new wound. High-resolution ultrasonography (HRU) is a technique developed as a tool for investigating wound-healing rates, because it can provide quantitative data without being invasive.
Ultrasonography has played a significant role in medical diagnostics for over 3 decades. Developments in technology during that time have resulted in sophisticated ultrasound machines that can produce 3-dimensional images. The apparatus functions by pulsing high frequency sound waves through a transducer at defined time intervals. This transducer then collates the echoes from tissues to produce an image through a central processing unit, which can be displayed on either a cathode ray tube or solid state display. The availability of advanced microprocessing has led to awareness of increased potential for the use of HRU, as analysis of scan results has become more reliable.
Advances in the development of ultrasound transducer technology are leading to improvements in the assessment of skin disease. Current applications of this developing technology include assessment of tissue edema and wound healing rates; imaging of skin thickness to evaluate diseases, such as psoriasis or scleroderma; and measurement of tumors in cases of skin cancers, such as melanoma, basal cell carcinoma, and squamous cell carcinoma.
The authors of the following article illustrate how the technique of HRU may be used as a mechanism to demonstrate how the shape of a wound can affect its rate of contraction. This is the first time that HRU has been used to assess wound healing in dogs and uses scans from a study of a wound healing gel containing the mast cell deregulator adelmidrol on open wounds to evaluate the HRU method and ways of calculating wound size. It does not attempt or aim to report on the efficacy of the wound gel in wound healing.
The results indicate that there is a need to develop algorithms to utilize the data from multiple scans to reliably quantify wound volume. Further development of the HRU technique will enable accurate evaluation of the stage of healing reached by deep, chronic wounds. This will lead to more efficient use of wound management materials with a consequent reduction in the costs associated with managing these wounds as well as a decrease in morbidity and a concurrent increase in quality of life for these patients. |
