[Echography, principles, techniques and applications to tropical and parasitological medicine (author's transl)]

After recalling the principles and general basis of ultrasounds, the authors consider the various modes of medical echographic exploration. A. mode, T.M. mode (time-motion); B. mode (bidimensional); D. mode (dynamic or in real time); Döppler mode. The technique of the examination, and the required preparation of the patients, are briefly reported. The basic echographic semiology is studied, considering the echos given by four main structures: 1) purely liquid with non echo, 2) non purely liquid with variable echos, 3) parenchymatous with many mixed echos (non perfect and non homogenous echos), 4) solid structures (bones, calculi) having complete impermeability to ultrasounds. Both parasitological and tropical medicine offer many and good opportunities for the use of echography in various controls: --liver: primitive tumors or parasitic abcesses, cysts, --gall ducts and bladder, --pancreas: pancreatitis, pseudocysts, --splenomegalies and cases of portal hypertension, --large vessels: ectasy, thrombosis, --kidneys: enlargement and cases of deceiving urography, --genital duct: sterility and pelvic tumors, --pregnancy: surveillance of pregnancy, hemorrhage, placenta praevia, foetal malformations, --heart: this chapter will not be considered in this paper. With regard to such a wide range of indications and to be low cost of its use, echography might be very useful in both tropical and parasitological medicine, when correctly applied and interpreted.