Film based scatter measurement in mammography

Film based measurements of scatter to primary ratio (s/p) have been made using the "beam stop" technique. Phantom material, radiographically equivalent to 100% glandular tissue, 100% adipose tissue and 50% glandular: 50% adipose tissue was used. These measurements have been made at 25 and 28 kVp for non grid and 28 and 30 kVp with grid for phantom thicknesses varying from 3 cm to 7 cm and 'D shaped' field sizes varying from 80 to 290 cm2. Results indicate that s/p is predominantly uniform across a mammographic image with a reduction towards the edge of the phantom. The values for s/p agree with previously published values determined from Monte Carlo calculation. Scatter primary ratio was found to be directly proportional to phantom thickness with little effect from field size. The effect of beam energy was significant in the non-grid case but reduced in significance with the use of a grid. The average measurement error was estimated at 4.5%. No variation in scatter primary ratio was detected between glandular and adipose phantom materials in this study.

Gall stone disease in African patients with sickle cell anaemia: a preliminary report from Yaounde, Cameroon

Cholecystosonography was undertaken in 90 patients with sickle cell disease aged 15 years and over. Gall stones were found in 26 (28.9%) patients. There was no sex difference, but the incidence increased with age from 13.2% at under 20 years to 75% at 30 years and over. The mean serum cholesterol and total and unconjugated bilirubin concentrations were not significantly different between patients with and without gall stones. As most (80.8%) stones were radiolucent they were probably of pigment type, containing little or no calcium, and further investigation into how they are produced is needed. Sickle cell patients with acute abdominal crisis should have gall bladder disease excluded before a diagnosis of vascular crisis is made.

Amoebic pericarditis

An unusual case of chronic amoebic pericarditis is reported in which the diagnosis of pericarditis was suggested on chest X-ray. The echocardiographic feature of multiple cystic lesions were mainly related to the left ventricle, there was thickening of the visceral pericardium, and some restriction to ventricular filling. The cysts contained anchovy sauce like material, and serological tests for amoebiasis were strongly positive. There was no evidence of an amoebic liver abscess. Clinically the patient improved with anti-amoebic treatment, but died later having refused surgery. The clinical picture may have been modified by earlier chloroquine administration.

Immunological studies in congestive cardiomyopathy in Cameroon

Significantly higher levels of immunoconglutinin were found in the sera of 40 Cameroonian patients aged between 15 and 80 years with congestive cardiomyopathy than in a matched group of normal Cameroonian controls. C3 values were also abnormal in the group with congestive cardiomyopathy, and a negative correlation was found between the C3 and immunoconglutinin values, indicating complement incorporation into immune complexes. Further, the levels of immunoglobulins G, M, and A were all raised, the most striking increase being of IgM, which was greater than in the normal controls and in a group with 'other cardiac disease' studied for comparison. Complement-fixing autoantibodies to cardiac muscle of the class IgG and IgM were found by immunofluorescence techniques in a significant proportion of the patients with congestive cardiomyopathy. Finally, evidence of trypanosomiasis was found by immunofluorescence tests in 27-5 per cent of patients with congestive cardiomyopathy, compared with 8-5 per cent of patients with other cardiac disease, and 1-9 per cent of normal Cameroonian controls selected randomly. We think that some cases of congestive cardiomyopathy in Cameroon may be caused by untreated subclinical attacks of African trypanosomiasis which produce immune complexes that damage the cardiac tissue where the parasite is lodged. Secondary autoimmune carditis modifies the course of the disease, with the resulting end-stage picture.

Immunological studies in onchocerciasis in Cameroon

Immunological studies were undertaken in a group of twenty patients with varying clinical manifestations of onchocerciasis. Significantly higher levels of immunoconglutinin, IgG and IgM, and alterations in C3 levels were found in the patient group than in controls. IgG and IgM complement-fixing antibodies to microfilariae of O.volvulus were detected in the sera of these patients. The lymphocyte transformation rate following PHA stimulation was high in patients with localised skin lesions in which the microfilariae were difficult to demonstrate in contrast to the low transformation rate obtained in those with diffuse lesions and in whom microfilariae were readily detected in skin biopsies. The significance of these findings is discussed.