[A-mode echography in surgery: a study of solitary thyroid nodules (author's transl)].

As part of their exploration of the possibilities afforded by A-mode ultrasonic investigation in several disorders of surgical interest, the authors report the results obtained in the study of solitary thyroid nodules. More precisely, after a brief explanation of ultrasonics, current apparatus for echography, and methods for echographic examination, they describe the semiological features exploited in A-mode echography: namely nodules with liquid content, mixed content, solid homogeneous content, and solid heterogeneous content. They conclude with considerations on the principles and indications of this diagnostic procedure in the light of their personal experience.