The Radiologic Changes in Sickle-Cell Anemia

Since Herrick (1) described sickle-cell anemia in 1910 there have been many reports of this disease in the literature. These have dealt with studies of the cell, the pathological basis of the disease, and the common as well as uncommon clinical findings. It is the purpose of this paper to present a radiologic study of sickle-cell anemia in order to demonstrate the effects on the entire organism, rather than on the bones alone, which can be recognized by radiological examination. Sickle-cell anemia affects all tissues of the body. Although there is a characteristic clinical picture, there are many variations depending on the particular pathological involvement of various organs, and because of this Wintrobe (2) has aptly named the disease “the little imitator.” Many investigators have discussed the theories of the cause of sickling. These have dealt with heredity, oxygen tension studies, and immunologic factors (3, 4, 5). The sickled cell loses its flexibility and appears fixed and rigid. Its length may be two to five, or more, times its original diameter, with long tapering processes projecting from the ends. Murphy and Shapiro (6) show that “capillary blockades” can be formed by these sickled cells. These lead to stasis of blood in the capillaries and small blood vessels, thromboses, and infarction. The clinical picture is associated with these thromboses and infarctions. The changes in the bones are due to two factors: (a) hyperplasia of the marrow secondary to a severe degree of hemolysis; (b) congestion and thrombosis, infarction, scarring, and regeneration of bone (6–13). The nervous system may be affected (14–18). Klinefelter (19), McKendry (20), Zimmerman and Barnett (21), Winsor and Burch (22), and Wintrobe (23) have shown the heart to be frequently involved. Indolent skin ulcers and other skin changes are often seen (24–26). Cholelithiasis and cholecystitis in young patients have been found by Schaefer (27) and Weens (28). This is thought to be due to the hyperbilirubinemia resulting from increased hemoglobin liberation. Progressive renal damage with fixation of the specific gravity is a frequent finding. Bauer (29), Diggs and Ching (30) and Yater and Hansmann (31) have shown this to be associated with a pathological picture of destruction of the glomeruli by accumulations of sickled red blood cells. Pulmonary thrombosis and infarction are common (30–31). Getzoff (33) reports priapism as a result of thrombosis. The pathological findings in the liver and spleen are well known (6, 7, 11, 30, 32). The factors that are responsible for the production of the crises of sickle-cell anemia are not well understood. Sherman (5) has found by experiments that increased leukocyte concentration, temperature elevation, and bacterial contamination are associated with acceleration of sickling. Clinically, infection is supposed to precipitate the sickle-cell crisis (2).