Background: The concept of deep tissue injury under intact skin helps us understand the pathogenesis of pressure ulcers, but the best method for detecting and evaluating deep tissue injury remains to be established.
Methods: Intermediate-frequency (10-MHz) ultrasonography was performed to evaluate deep tissue injury. The authors analyzed 12 patients (nine male patients and three female patients aged 16 to 92 years) who showed deep tissue injury-related abnormal findings on ultrasonography at the first examination and were followed up until the pressure ulcer reached a final stage.
Results: The stage of ulcer worsened in six of 12 cases compared with baseline, and healed in the remaining six patients. The authors recognized four types of abnormal signs unique to deep tissue damage in ultrasonography: unclear layered structure, hypoechoic lesion, discontinuous fascia, and heterogeneous hypoechoic area. Unclear layered structure, hypoechoic lesion, discontinuous fascia, and heterogeneous hypoechoic area were detected at the first examination in 12, 10, seven, and five patients, respectively. Unclear layered structure and hypoechoic lesion were more commonly seen in pressure ulcers in deep tissue injury than the other features, but the follow-up study suggested that discontinuous fascia and heterogeneous hypoechoic area are more reliable predictors of future progression of pressure ulcers.
Conclusions: The use of intermediate-frequency ultrasound reliably identified deep tissue injury and was believed to contribute to prevention and treatment of pressure-related ulcers. The results suggest that specific ultrasonographic characteristics may predict which pressure ulcers will progress.