以高頻超音波逆散射訊號及統計參數 評估燒燙傷組織的癒合

Wound Healing of Burnt Tissues Assessed by High Frequency Ultrasonic Backscattered Signals and Statistical Parameters

林奕勳(Yi-Hsun Lin)

指導教授 ： 王士豪

中原大學/工學院/醫學工程研究所/碩士(2007年)

https://doi.org/10.6840/cycu200700530

摘要

一般傷口癒合的研究實驗，大多使用動物樣本，採用皮膚組織切片來評估癒合情形。由於組織切片的製作過程耗時，對動物產生侵入式傷害，且無法對同一傷口長期觀察其癒合狀況。由於高頻超音波具有非侵入及高解析度影像的優點，可用來即時就地長期觀察傷口組織之變化。先前研究証實超音波逆散射訊號的包封機率密度函數與介質內散射子濃度、大小、分佈狀況以及散射橫斷面的均勻程度有關。所以本研究嘗試以高頻超音波影像針對燒燙傷皮膚組織的燙傷程度及傷口癒合情形做定性觀察，另以逆散射訊號的強度及包封統計模型參數定量評估組織之特性。
本實驗使用雌性Wistar大鼠，分為燒燙傷程度及傷口癒合之評估兩組進行實驗，第一組實驗以100℃的黃銅片分別接觸單隻老鼠背部皮膚組織5秒、10秒、15秒及20秒，以產生不同程度的燒燙傷，再以高頻超音波影像系統掃描燒燙傷組織並計算逆散射訊號之積體逆散射(integrated backscatter, IB)、均方根值 (root mean square, RMS)與Nakagami參數以評估大鼠之燙傷程度。第二組實驗以100℃的黃銅片接觸老鼠背部皮膚組織20秒，再每日掃描傷口組織之高頻超音波訊號，並計算相關參數，共持續28天。
實驗結果顯示，燒燙傷程度愈嚴重， RMS、IB與Nakagami參數皆以指數函數的趨勢下降，能有效評估分辨燒燙傷程度。在燒燙傷組織癒合部分，IB、RMS與Nakagami參數在燙傷後1至10天呈現下降的趨勢，隨著組織逐漸癒合，在第11天至28天呈現上升的趨勢。其中Nakagami參數上升的趨勢較明顯，能有效評估傷口癒合情形。高頻超音波影像亦可觀察傷口癒合時皮膚組織的變化。

關鍵字

高頻超音波 ； 傷口癒合 ； Nakagami參數 ； 積體逆散射

並列摘要

Most of wound healing studies were performed using histological slices sampled from the skin tissue of animal models to assess the healing process. The preparation of histological slice is time consuming and invasive, which does not allow long term observation on the healing progress of a wound area. High frequency ultrasound may be applied to long term in situ observe changes of wound tissues due to its non-invasive and high resolution capabilities. Furthermore, previous studies have shown that the probability density function of the ultrasonic backscattered envelope is related to the homogeneity of scatterer concentration, size, distribution, and scattering cross section in the medium. Thus, this study is to qualitatively observe the degree and healing process of burnt skin tissues using high frequency image and to apply the strength and envelope statistical parameter of ultrasonic backscattered signals to quantitatively assess biological tissues.
The experiments were carried out using Wistar rats, in which two groups of investigation were performed. Firstly, the skin tissues in the back area of each Wistar rat were burned with a 100℃ copper plate respectively for 5, 10, 15, and 20 seconds to bring out different degrees of burn wound. Those wound tissues were scanned by a high frequency ultrasound imaging system. Subsequently, the integrated backscatter(IB), root-mean-square value(RMS), and Nakagami parameter of the backscattering signals were calculated to evaluate degree of burn in the rats. Secondly, the wound skin tissue was burnt with 20 seconds, in which the high frequency ultrasonic signals were scanned daily. The related parameters were calculated and that measurements were performed for 28 days.
Results demonstrated that the IB, RMS, and Nakagami parameter were able to differentiate the increase of degree of burn. The ultrasonic parameters decrease exponentially with the increase of degree of burn. For the assessment of healing process of a burn tissue, values of IB, RMS, and Nakagami parameter decreased between the first and 10th day after the skin was burned and tended to increase from the 11th to 28th day associated with the healing of tissue. The Nakagami parameter showed better tendency than other parameters to assess the wound healing process. The high frequency ultrasound image is also capable of observing the variations of skin tissues during wound healing progress.

並列關鍵字

Integrated backscatter ； High frequency ultrasound ； Nakagami parameter ； Wound healing

參考文獻

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