Diagnostic ultrasound ( PDFDrive )

160 PART II Abdominal and Pelvic Sonography
A
B
C
FIG. 5.32 Splenic Laceration. (A) Coronal image shows
irregular, ill-deined hypoechoic areas (arrows). There is a small
amount of blood (hypoechoic) around the spleen. (B) and (C)
Different patient. (B) Longitudinal image shows ovoid hypoechoic
areas. (C) Coronal reconstructed image from contrast-enhanced
computed tomography demonstrates the splenic lacerations and
large, perisplenic hematoma.
S
FIG. 5.33 Accessory Spleen. Coronal sonogram shows an accessory
spleen adjacent to the inferior medial portion of the spleen.
known as situs solitus. he mirror image condition is called situs
inversus. Between these two extremes is a wide spectrum of
abnormalities called situs ambiguus. Splenic abnormalities in
patients with visceral heterotaxy consist of polysplenia and
asplenia. Interestingly, patients with polysplenia have bilateral
let-sidedness, or a dominance of let-sided over right-sided
body structures. hey may have two morphologically let lungs,
let-sided azygous continuation of an interrupted inferior vena
cava, biliary atresia, absence of the gallbladder, gastrointestinal
malrotation, and frequently cardiovascular abnormalities.
Conversely, patients with asplenia may have bilateral rightsidedness.
hey may have two morphologically right lungs,
midline location of the liver, reversed position of the abdominal
aorta and inferior vena cava, anomalous pulmonary venous
return, and horseshoe kidneys. he wide range of possible
anomalies accounts for the variety of presenting symptoms, but
absence of the spleen itself causes impairment of the immune
response, and such patients can present with serious infections,
such as sepsis and bacterial meningitis. 6
Polysplenia must be diferentiated from posttraumatic
splenosis. 91 Splenosis is an acquired condition deined as autotransplantation
of viable splenic tissue throughout diferent
anatomic compartments of the body. It occurs ater traumatic
or iatrogenic rupture of the spleen. 92 Nuclear medicine imaging,