[Ultrasonic demonstration of lipomatous tissues and tumors (author's transl)]

The echostructure of 5 subcutaneous lipoma, 2 renal angiomyolipomas, and 37 renal fibrolipomatoses is analysed. The subcutaneous lipomas were echo-pour, and the angiomyolipomas echogenic, while 33/37 renal fibrolipomatoses were found to be echo-pour and 4/37 echogenic. All renal fibrolipomatoses had ill-defined margins and did not show increased sound-transmission behind the fibrolipomatoses. Experimental studies show that the echogenicity is depended on the number of acoustic interfaces fatty tissue/nonfatty tissue. Echogenic fatty tissue has a greater content of fibrous/collagen fibres and a greater number of interfaces fatty tissue nonfatty tissue. Collagen fibres with the high elastic modulus are a major factor of echogenicity.