FIGURE 131.31 Normal soft tissue Technique Most soft tissue structures are superficial and are best interrogated using a highfrequency linear transducer Scanning should extend from nearby uninvolved structures through the entire region of the affected area Images should be obtained in both the longitudinal and transverse planes Normal dermis and epidermis appear hyperechoic in relation to the deep subcutaneous fat globules (Fig 131.31 ) Fascia appears as a linear hyperechoic layer and muscle can be identified as hypoechoic cylindrical structures surrounded by hyperechoic perimysium (Fig 131.32 ) Interstitial edema in cellulitis is apparent as hypoechoic fluid separating the hyperechoic fat globules This effect is known as “cobblestoning” (Fig 131.33 ) Abscesses have a variable appearance, but most often are identified as anechoic or hypoechoic collections of fluid (Fig 131.34 ) Gentle compression of the abscess with the US probe can elicit fluid movement confirming the presence of a fluid collection ( Video 131.30 ) Pitfalls Cysts appear as anechoic structures with posterior enhancement and can be mistaken for abscesses However, they often have a more regular oval shape and not exhibit surrounding interstitial edema as seen in cellulitis Normal or