Ian Donald

FOETAL CEPHALOMETRY BY ULTRASOUND.

TO ascertain the size and to observe the growth of the foetus in utero are matters of great importance to the obstetrician, yet the methods hitherto available have been either imprecise or of limited application. Practically the only part of the foetus which can be measured is the head; this measurement has been made by X-rays with varying reliability. The use of the ultrasonic echo-sounding technique described here has, we believe, advantages over radiography,

SAFETY OF DIAGNOSTIC ULTRASOUND IN OBSTETRICS

Abstract Ultrasound examinations were carried out on 1114 apparently normal pregnant women cared for in three different centres, at various stages of pregnancy and with differing ultrasonic frequencies throughout. The incidence of fetal abnormality in the group was 2·7%. Neither the time in gestation of the first examination nor the number of examinations seemed to increase the risk of fetal abnormality.

INTRAUTERINE GROWTH ASSESSED BY ULTRASONIC FOETAL CEPHALOMETRY

MEASUREMENT of the biparietal diameter of the foetal head in utero by pulsed ultrasound was introduced by Donald in 1959 and first reported in 1961 (Donald and Brown). Serial measurements by this technique were used to study intrauterine foetal growth and the method was suggested as a means of detecting placental insufficiency (Willocks, 1962a and b). Willocks et al. (1964) showed that there was a correlation between birthweight and the ultrasonic measurement of the biparietal diameter before birth; in two-thirds of the cases foetal weight could be estimated to within 411 pound. The average rate of growth of the biparietal diameter in the last 10 weeks of pregnancy was found to be 0-16 cm. a week, and growth appeared to be retarded in cases of albuminuric pre-eclampsia and in placental insufficiency. Studies in the United States (Taylor et al., 1964; Anderson and Niswonger, 1965; Thompson et al., 1965; Thompson, 1966; Kohorn, 1967) and in Europe (Kratochwil, 1966) have confirmed this work. Thompson (1966) measured the biparietal diameter at varying intervals from the 28th week to term in 70 patients and found the average rate of growth was 0.18 cm. a week until the 40th week when the growth curve tended to flatten. We present here our recent experience in the use of serial biparietal foetal cephalometry at the Queen Mother’s Hospital, Glasgow.

SONAR IN THE DIAGNOSIS OF EARLY PREGNANCY AND ITS COMPLICATIONS

DURING the investigation of abdominal masses by pulsed ultrasound (Donald et al., 1958) it was found that a foetus could be visualized as early as fourteen weeks. This had been found more or less by accident when examining a case thought clinically to have uterine enlargement due to fibromyomata. examination. We have since explored the earliest period of gestation at which foetal echoes can be made out. We also wished to determine if sonar examination would assist in the diagnosis of certain complications of early pregnancy. The camera recording the display of the scan is of Polaroid type and by using fast developing film a pictorial record of the scan is available within 10 seconds of completion. This is important in assessing what other pictures could be of value and thus reduces the time spent on

The diagnosis of blighted ovum by sonar.

The outcome of 141 cases of bleeding in the first trimester of pregnancy has been correlated wit the findings obtained at the first and subsequent ultrasonic examinations. In 66 patients who aborted the ultrasonic appearances suggested a diagnosis of blighted ovum in 57. In 10 of the 75 patients in whom pregnancy continued the ultrasonic appearance was abnormal on at least one occasion.

PLACENTOGRAPHY BY SONAR

PLACENTOGRAPIIY and localization of the placenta are not necessarily the same thing. Localization may demand no more than an indication whether or not the placenta is praevia, whereas placentography implies a more precise depiction of the placenta in the uterus-its margins, its thickness, whether situated on the anterior or posterior wall of the uterus-and, if possible, it should give some information about some of the physical characteristics of the placenta as well (Figs. 14). Most current techniques, with the exception of soft tissue radiography, depend upon demonstrating the maternal vascular placental bed from which the level of the placenta is inferred, whether by arteriography, by thermography or by the use of radioactive isotopes. Sonar is a complete departure from these methods inasmuch as it seeks to reveal the placenta in all its dimensions by means of its echo-producing characteristics to high frequency pulsed ultrasound. We have previously described our use of ultrasonic placentography (Donald and Abdulla, 1967a and b; Donald, 1968a and b), and Gottesfeld el ul. (1966) have published their experience of over 200 cases with such a technique. We here present our own experience over the last two and a half years at the Queen Mother’s Hospital. In 1965, the year after this hospital was opened, the Scottish Home and Health Department provided us with new ultrasonic equipment, and after some months of modification, calibration and adjustment, the number of cases investigated began to build up rapidly as experience and confidence mounted. I t is now

New problems in sonar diagnosis in obstetrics and gynecology

Departments of radiology will inevitably become more involved in sonar diagnosis. Technical expertise can be developed by nonmedically trained staff in routine applications such as fetal cephalometry and placental localization but not in diagnostic problems. New applications include examination of previous cesarean section scars. Kidney examination is indicated in cases of recurrent urinary tract infection. There is scope for more study of the placenta in situ. Experimental work to assay the safety of sonar is reviewed.

DIAGNOSTIC USES OF SONAR IN OBSTETRICS AND GYNAECOLOGY

THE term “sonar” stands for “sound navigation and ranging” and derives from the technique of U-boat detection. In actual fact we use ultrasound of very high frequency in the megacycle range in order to secure directional control of the energy beam and hence the location of echoes from reflecting interfaces between tissues within the body of differing physical properties. We started to explore the clinical usefulness of this subject ten years ago, having only the experience of industry in the detection of flaws in metals to draw upon, and we began by borrowing industrial flaw-detection equipment. Work had also started in the United States, principally in Denver by Howry and Bliss (1 952) and Holmes et al. (1954, 1963), in the case of internal organs such as the liver, and in Minneapolis by Wild and Reid (1952), mainly in investigation of the breast. Gynaecological tumour masses and the pregnant uterus were new fields for us. Work of a similar nature is now being carried out in Denver (Taylor et al., 1964; Thompson et ul., 1965). Our technique of compound sector scanning for recording our echoes photographically in two-dimensions has already been described on numerous occasions (Donald et ul., 1958, 1961, 1963, 1964). The kind of work we have covered in a five-year period from 1960 onwards, by which time our results were beginning to be worth cataloguing, is given in Table I. This does not include many hundreds of foetal biparietal measurements. It will be seen that we have often failed to arrive at a correct interpretation of our results, usually from lack of experience, less often from technical mistakes. We continue to learn the hard way. The normal abdomen (Fig. 1) simply shows strong echoes from bowel lying immediately beneath the abdominal wall. In the pregnant uterus a baby’s head is usually easy to find and a measure of its size can be obtained either in transverse or longitudinal section (Fig. 2). This, of course, is very striking in hydrocephalus (Fig. 3). In cephalic presentations the best views are obtained in longitudinal section (Fig. 4). Two years ago I became interested in studying the changes in the uterus and its contents in early pregnancy (Donald, 1963). This is difficult when the uterus has not yet risen out of the pelvis because bowel blocks the ultrasonic “view”. However, by encouraging the patient to

The safety of using sonar.

brought expressions of pleasure that had not been seen since early childhood. There is much to be learnt about the nature, causes and treatment of self-injurious behaviours. Most, if not all, seem to proceed from activities that have some biological function at their inception, but like certain obsessional behaviours in adults, they may elaborate and progress to a point of causing grave disability. Comparisons of different methods of treatment are desirable, in particular the publication of failures in treatment as well as successes. In the light of existing knowledge, treatment should proceed in the following stages. Firstly, aggravating factors such as emotional deprivation, pain, illness and sheer boredom must be eliminated and the child given rewarding experiences. Secondly, reinforcement of the behaviour by giving attention to it must be avoided, while much attention should be given when desirable behaviours (or an absence of self-destructive behaviours) are observed. If the behaviours still persist, their prevention by suitable restraints and guards should be attempted, reserving aversive electric shock treatment for the most intransigent cases only. Shock treatment raises many ethical as well as practical problems and its use should be limited to severe and intractable cases in which all other methods have failed. CYRIL WILLIAMS Borocourt Hospital, Wyfold, Reading RG4 9JD.

Sonar: What it can and cannot do in obstetrics.

T H E use of sonar in obstetrical diagnosis has recently begun to escalate in many parts of the Western World. Inevitably under such circumstances bottlenecks in training are making themselves felt. Apparatus is being bought in many centres before ensuring the expertise with which to operate it and there is the risk of disillusionment which can do the ultimate exploitation of this fairly new subject nothing but harm. It is the purpose of this lecture therefore to review the kind of service that can reasonably be expected from colleagues, be they obstetricians or radiologists, who have acquired some practice and confidence with their machines which after all involve some of the complexity of a cathedral organ. Only practice can familiarise the organist with his stops and the effect which he can expect. This cautionary attitude is necessary because the value of this new diagnostic medium is directly related to a basic understanding of its potential and to be worth while must be capable of providing something of clinical value to the obstetrician and his charge.