Paediatric ultrasonography II: A and B ultrasonic scans of heads of infants and children

Abstract

Echoencephalography is a simple, noninvasive procedure used in the diagnosis of intracranial lesions through the intact skull by ultrasonic testing. It is especially useful in the paediatric age group because of the relatively thinner skull bone. In the University Department of Paediatrics in Singapore, it has become a first-line investigation in selected patients since August l976. This paper presents the authors' initial experience with A and B scans. A total of 61 children (age range one month to 14 years) admitted to the department over the last nine months with various neurological presentations (e.g. unexplained fits, large head for investigation, localising clinical signs) had A scans done. Of these children, a further 30 also had subsequent B scans. A-scan measurements of midline, brain mantle thickness, third ventricular size and other echoes were made as a routine, and B-scan pictures showing composite two-dimensional structures (both normal and abnormal, including midline shifts and 'tumor' echoes if present), at different planes were taken where indicated. The authors have learnt to recognise normal and abnormal structures and have also been able to demonstrate intracranial space-occupying lesions in 3 patients (two cerebral tumours and one cerebral abscess) and hydrocephalus in 6 patients. It is concluded that A and B ultrasonic scans in paediatrics is a useful aid in the screening of patients for more detailed and invasive neuroradiological techniques such as carotid angiography and air studies, with all their attendant risks, and in the follow-up of certain patients to determine the success of surgical procedures such as shunts for hydrocephalus.