Subarachnoid spaces in infants and young children

In computed tomography of young children, the frontal subarachnoid spaces were sometimes noted to be prominent in scans which were otherwise normal. These apparently enlarged spaces raise the suspicion of possible subdural hygromas. The objective of this study is to show the trend and variability of the intracranial subarachnoid spaces, especially the frontal subarachnoid spaces with age in children. Computed tomographic scans of 39 children up to five years of age with normal head scans were assessed for sizes of the subarachnoid spaces which were subjectively graded from I to V. Grade I is not visible while grade V is borderline enlargement. The sizes of the subarachnoid spaces were found to be more variable in those below the age of two years, with a tendency to be larger compared to older children. Based on these observations, prominent subarachnoid spaces in those below the age of two years should be considered a normal variant. A diagnosis of subdural hygroma must, therefore, be made with caution.

Comparison of accuracy of magnetic resonance angiography with conventional angiography: a report of 45 cases

To investigate the accuracy of magnetic resonance angiography (MRA), compared to conventional cerebral and carotid angiography (CA), 45 patients underwent MRA within one week after CA. The MRA involves a FISP (fast imaging steady precession) pulse sequence base on three-dimensional time-of-flight phenomena at 1.0 Tesla. Repetition time of 35-40 msec, echo time of 7-11 msec and a flip angle of 15-25 degrees were used to optimise the depiction of blood flow as high intensity. Volume data were then submitted to a maximum intensity projection programme and viewed at multiple arbitrary projection angles rotating through the three orthogonal planes. Venous structures were suppressed with a presaturation slab superior to the area of interest. All significant stenoses and occlusions at the carotid bifurcation and circle of Willis were detected. Other than the carotid siphon (61.4%), the rest of the arteries have above 70% complete agreement between MRA and CA. The carotid bifurcation and basilar artery show complete agreement of 75.4% and 76.2% respectively, making MRA a simple sensitive screening procedure. This report shows that MR angiography has an important role in the evaluation of blood flow in the head and neck regions.

Cerebral venous angioma--a misnomer?

Cerebral venous angioma (CVA) is an embryonic venous malformation. Its incidence was thought to be radiologically rare previously but with greater clinical awareness, the routine use of contrast enhanced computerised tomography (CECT) and the increasing availability of magnetic resonance imaging (MRI), it is no longer perceived to be a rare lesion. In fact, it is the commonest intracranial vascular malformation seen at autopsy. We report our experience of 15 patients with cerebral venous angiomas, 14 of whom had their lesions confirmed by cerebral angiography. Presentation was variable and non-specific. The commonest presenting symptom was headache (n = 7). Other clinical presentations included epilepsy (n = 5), intracerebral bleed (n = 4, two were thought to be due to an associated cerebral cavernous angioma and one was due to a ruptured arteriovenous malformation) and non-specific giddiness (n = 3). Six were diagnosed incidentally. Based on the angiographic findings and the relatively benign clinical course in the majority of our patients, we believe that CVA is a developmental anomaly and should not be excised routinely.

Radiologic manifestations of rheumatic joint diseases in the plain radiograph

In the assessment of radiologic manifestations of joint diseases, rheumatoid arthritis (RA) is the disease to which all others are compared. Knowledge of its characteristics form the basis of the other conditions. To understand the changes seen on the plain radiograph, it is essential to understand its pathophysiology first so that the manifestations of each disease can be appreciated more fully. Due to space constraint, I shall only discuss the main forms of rheumatic joint disease. Other examples of erosive arthropathies, although not rheumatic in origin, will also be included as they form part of the differential diagnosis of an erosive arthropathy, eg gout and psoriasis.

Percutaneous lung aspiration biopsy: a comparison between two fine needles

Fine needle lung aspiration biopsy is now a well established method of obtaining tissue for histopathological diagnosis. It is fast, simple and reliable, and has a very low complication rate. We report our experience using two fine needles, the Turner and the EZ-EM Cut-Biopsy needles, comparing their yield and complication rates. We found that both needles had comparable diagnostic yields (65% with the Turner, and 71% with the EZ-EM) and complication rates. We also found that in most cases, aspirates alone were sufficient for diagnosis, and that obtaining tissue cores with larger bore EZ-EM needles did not significantly influence the diagnostic outcome. We conclude that both the Turner and the EZ-EM needles are equally effective and safe in percutaneous lung aspiration biopsy. The least traumatic needle should be used except when the cytological diagnosis is nonspecific inflammatory cells or inadequate, in which case a repeat with a cutting needle is advised to obtain a core of tissue.

Air in the cervical annulus--the lucent cleft sign

The lucent cleft sign is a sign of soft tissue injury. It was first described as a sign of acute cervical injury but it is neither confined to cases of trauma nor the cervical region. The sign is also seen in degenerative disease and in the lumbar spine. The lucent cleft sign is seen anteriorly, as an area of hyperlucency above the superior end plate of the vertebra. It is the result of a partial tear of the annulus. In complete avulsion, the sign may be absent and the radiograph, completely normal. We report our experience of 15 patients with the lucent cleft sign. Our patients are relatively young (commonest age group 30-35 years) and the majority (10 patients) had a history of acute trauma. Four patients had non-specific (3 cervical and one lumbar) aches while in the last patient, the lucent cleft was an incidental finding. Although we only documented the disappearance of the sign in 4 patients, we believe that with healing, the sign will eventually disappear. Although the sign is transient, it is useful as it may be the only sign present in cases of trauma.

Early local experience of ankle arthrography and its influence on management of patients with ankle injury

Ankle arthrography was performed on 64 patients with a history of ankle injury from 21 January 1986 to 11 October 1988. There was a male predominance in the ratio of 15 to 1 and the mean age of our patients was 22 years. A total of 65 arthrograms were obtained as one patient had bilateral ankle arthrograms. Of these, 29 arthrograms were normal. A year after completing this study, we attempted to retrieve our patients' case-notes and reviewed their subsequent management. Our results showed that multiple factors influenced the further management of our patients and arthrogram did play a role in this respect.

Foetus in foetu--a case report

A three-month old baby presented to the Paediatric Department with a problem of abdominal distension. Clinically, he had a large right abdominal mass which on investigations suggested a teratomatous lesion. At operation, a foetus-like tumour mass was located in the retroperitoneal space. A diagnosis of foetus in foetu was made. A close differential of a retroperitoneal teratoma is discussed and comparison with confirmed cases made.

Basal ganglia calcification on computer tomographic scan. A clinical and radiological correlation

Computerised tomography of the brain was used to demonstrate basal ganglia calcification which may be of an insufficient degree to be seen on skull X-ray. Cases referred for CT scan from hospitals in Singapore for various reasons over a period of 12 months were studied for basal ganglia calcification. There was a startlingly high incidence of 1.5%, as 47 cases (all except 2 were Chinese) showed such calcification. In 42 cases there was no evidence of basal ganglia calcification on skull X-ray. 16 cases showed neurological affection, fits being the commonest manifestation. An unexpected finding was that no case had abnormality of calcium metabolism or evidence of hypoparathyroidism or pseudohypoparathyroidism. The CT scan is very sensitive in demonstrating minimal basal ganglia calcification and our impression is that such calcification is common.

A case of insulinoma diagnosed by plasma insulin, selective pancreatic angiography and computerised tomography

A 33 year old woman with benign islet cell adenoma in the head of the pancreas with hyperinsulinism is reported. The application of blood glucose levels with simultaneous plasma insulin assays, selective angiographic and computerised tomographic studies in its diagnosis and localisation of the tumour is discussed. After enucleation of the insulinoma, the patient recovered.