The significance of some reflections in “Echo-encephalography”

Abstract

Echo-encephalography, described by LekseU (1955), consists in the transmission into the skull of a rather narrow beam of ultrasound, part of which is reflected to the transmitter. This technique enables one to measure the distance between the reflecting surfaces arid the transmitter, in order to derive certain conclusions about structures existing within the skull.It is obvious that this method offers certain advantages to the usual X-ray techniques, for in the latter ease the total quantity of transmitted energy is visualized on the X-ray film as a density. On a normal X-ray film the skull appears to be "empty", the differences in density of the various structures being too small to cause appreciable differences in density on the X-ray film.Only when the skull contains special struetnres with a considerably differing density (nearly always ealeifications) is it possible to visualize these structures. Therefore we are obliged to have recourse to the use of contrast media of differing density to visualize certain structures, which, however, leads to an intervention not always acceptable for the patient.By the use of echo-eneephalography such an intervention can be avoided. One could ask which structures in the skull contents are involved in the reflection of the ultrasound. It appears that such structures must be present at several places, for reflections are obtained at nearly every direction of transmission, so that it is not probable that a specific structure, for instance the pineal body, should be the unique cause of the reflections.

Technical Assessment of Ultrasonic Cerebral Tomosphygmography and New Scientific Evaluation of Its Clinical Interest for the Diagnosis of Electrohypersensitivity and Multiple Chemical Sensitivity

“…In fact, after the identification of ultrasounds and use of echoencephalography in 1956 by L. Leksell [ 9 ], numerous international scientific publications have confirmed the existence of a spontaneous natural cerebral pulsatility that is synchronous with cardiac systoles [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ].…”

Detection of ventricular landmarks by two dimensional ultrasonography.

“…1), Gordon (1959), and de Vlieger and Ridder (1959) reported a double echo corresponding to the fissure of the third ventricle and a single echo at a higher level corresponding to the septum pellucidum. This was confirmed by Jeppsson (1960) in infants, and by ter Braak, Crezee, Grandia, and de Vlieger (1961), using simultaneous US and pneumoencephalography (PEG). An experimental confirmation of these data was given by Lithander (1961) who introduced a needle indicator in proximity to the reflecting interfaces on excised brains.…”

Ultrasonics in Medicine

“…Workers in Scandinavia and Holland (Leksell 1958, Lithander 1961, Jeppsson 1961, Braak, Crezee, Grandia and Vlieger 1961 used the commercial Krautkraemer instruments a t frequencies of 2 Mcis for adults, and 4 Mc/s for children, with a single barium titanate probe 24 mm in diameter. Workers in t'his country (Jefferson 1962, Ford andAmbrose 1963) use commercial Kelvin and Hughes apparatus at a frequency of 1.5 iVc!…”