Diagnostic ultrasound ( PDFDrive )

CHAPTER 5 The Spleen 157
infarction should be the irst diagnostic consideration 67,68 (Figs.
5.27 and 5.28). However, the sonographic appearance of splenic
infarcts varies and includes multinodular or masslike changes
with irregular margins. 69 he temporal evolution of the ultrasound
appearance of splenic infarctions has shown that the echogenicity
of the lesion is related to the age of the infarction. Infarctions
are hypoechoic in early stages and progress to hyperechoic lesions
when ibrosis develops over time. 70,71
Other Abnormalities
Sickle Cell Disease
Sickle cell disease almost always afects the spleen. he most
common splenic complications are autosplenectomy, acute
sequestration, hypersplenism, massive infarction, and abscess.
In homozygous sickle cell disease, multiple infarcts generally
result in a small, ibrotic spleen and complete loss of function
(autosplenectomy). Although promising new therapies are being
developed, many homozygous sickle cell patients become asplenic
in late childhood or early adulthood. his results in a small
spleen, oten diicult to visualize, with a difuse echogenic
appearance. Patients with heterozygous sickle cell disease oten
present with splenomegaly and may demonstrate the sequelae
of infarction. 72,73 In some patients, areas of preserved splenic
tissue are present in an otherwise small and ibrotic spleen, and
these should not be mistaken for an abscess or mass.
Acute splenic sequestration is a life-threatening complication
of sickle cell disease and typically occurs in infants and children
with homozygous sickle cell disease. It represents sudden trapping
of blood in the spleen, resulting in splenic enlargement. On
ultrasound, the spleen is larger than expected and heterogeneous
with multiple hypoechoic areas. 72 It is important to recognize
that in homozygous sickle cell patients, an apparently normal-sized
spleen may actually indicate splenomegaly.
Gaucher Disease
In Gaucher disease, splenomegaly occurs almost universally, and
approximately one-third of patients have multiple splenic nodules.
hese nodules frequently are well-deined hypoechoic lesions,
but they may also be irregular, hyperechoic, or of mixed echogenicity
74,75 (Fig. 5.29). Pathologically, these nodules represent
focal areas of Gaucher cells associated with ibrosis and infarction.
In rare cases, the entire spleen may be involved, with ultrasound
showing a difuse heterogeneous spleen.
FIG. 5.27 Splenic Infarct. Triangular hypoechoic infarct (arrow) in
the superior aspect of the spleen extends to the splenic capsule.
Gamna-Gandy Bodies
Gamna-Gandy bodies (Gamna nodules) are ibrosiderotic nodules
that result from organized focal hemorrhagic infarcts, typically
seen in congestive splenomegaly and sickle cell disease. Gamna-
Gandy bodies appear as multiple punctate hyperechoic foci on
ultrasound but are usually better seen on MRI. 76
A
B
FIG. 5.28 Splenic Infarct. (A) Coronal image shows a well-deined hypoechoic central area reaching the splenic capsule medial and lateral in
a patient with splenomegaly receiving peritoneal dialysis. (B) Corresponding computed tomography scan after intravenous contrast demonstrates
the wedge-shaped nonenhancing area in keeping with an infarct.