Paediatric Imaging

Thalassaemia

a defect in either the alpha- or betaglobin chain synthesis seen mainly in patients of Eastern Mediterranean origin. Two forms are described: thalassaemia major, which is also known as Cooley's anaemia, which is homozygous; and thalassaemia minor, which is heterozygous.

Clinical manifestations are those of anaemia secondary to the abnormal haemoglobin. There is splenomegaly and because of the extramedullary haematopoiesis and abnormal marrow there are secondary bony changes with prominent parietal and frontal bones. Secondary effects may be demonstrated in the heart in which there is cardiomegaly, plus or minus pericardial effusion or pericarditis; CNS changes occur secondary to intracranial haemorrhage or are caused by compression; enlargement of the adenoids and tonsils is seen.

Radiologically, the manifestations are:

  • marrow hyperplasia (Fig.1)

  • osteopenia of the skull vault with widening of the diploic space, a "hair on end" appearance, prominent frontal bones and thinning of the outer table (Fig.2). There may also be hypertelorism and hyperplasia of the paranasal sinuses.

  • In the spine there is osteopenia, coarse trabeculae, a bone within bone appearance either in the vertebral bodies or in the ribs and there may be secondary collapse of the vertebral bodies secondary to the osteopenia. The ribs appear expanded.

  • In the long bones, metacarpals (Fig.3) and metatarsals, there is widening of the medullary cavity with thinning of the cortices, Erlenmeyer flask deformity (Fig.4), premature growth plate fusion and sometimes pathological fractures. Avascular necrosis may ensue.

    On a chest radiograph one may see the bony abnormality together with evidence of cardiomegaly. In severe cases, paraspinal soft tissue masses reflect the extramedullary haematopoiesis. Repeated blood transfusions can lead to evidence of haemochromatosis, increased echo density of the liver. For further description, thalassaemia.

    HC

    • To view high resolution images,
    please register first.

    Click  here to register.

    Already registered? Enter your e-mail in the window below.
    Re-register

    Fig.1

    CT examination of the paranasal sinuses (soft tissue window (a) and bone window (b)), demonstrating obliteration of the sinuses by the expanded medullary cavity of the maxilla.
    Thalassaemia, Fig.1 (a)
    Thalassaemia, Fig.1 (b)
    Thalassaemia, Fig.2
    Thalassaemia, Fig.3
    Thalassaemia, Fig.4