Spleen

1. Topic:
Spleen
Prepared By:
Safi. Khan

2. ANATOMY
The spleen is an intraperitoneal organ that occupies the superior,
posterior, and lateral aspects of the left upper quadrant.
It is normally in continuity with the diaphragm.
It contacts the kidney and splenic flexure inferiorly and the
stomach and tail of the pancreas medially.
The splenic artery arises from the celiac axis and travels along the
posterior superior aspect of the pancreas toward splenic hilum.
It often becomes quite tortuous with aging.
The splenic vein exits the spleen at the hilum and initially travels
superior to the tail of the pancreas.
The splenic vein is located slightly inferior to the splenic artery.

8. The splenic parenchyma appears very homogeneous on
sonograms, and it is more echogenic than the liver and is
considerably more echogenic than the left kidney.
Normal spleen. A, Longitudinal view of the spleen (S). The
length (cursors) is 11.0 cm.
B, Transverse view of the spleen (S). The thickness (cursors) is
4.3 cm.

9. C, Longitudinal view of the spleen (S) and the left kidney (K)
shows that the spleen is considerably more echogenic
than the kidney.
D, Longitudinal view of the spleen (S) and the tail of the
pancreas (P) shows that in this patient the spleen is less
echogenic than the pancreas

10. The measurement of splenic size in the detection of splenomegaly
exceeds 13 cm in a coronal plane is a reasonable cutoff between
normal and enlarged.
A thickness of 6 cm, measured from the hilum to the opposite edge,
is a useful cutoff when the length is borderline.
The normal spleen is crescent shaped.

11. Small nodules of splenic tissue often located in the left upper
quadrant adjacent to spleen & referred as splenules, accessory
spleens, splenunculi, and supernumerary spleens.
They are usually small (<3 cm), but can enlarge and become more
evident when spleen itself enlarges or when spleen is removed.
They tend to be round or ovoid and are isoechoic to the spleen.
Splenule. A, Longitudinal view of spleen shows an isoechoic mass
(cursors) in the splenic hilum characteristic of a splenule.
B, Power Doppler view shows internal blood flow arising from a
branch of the splenic artery.

13. Splenic clefts are also relatively common. They appear as thin,
bright, linear reflections that extend from the periphery of the
spleen into the splenic parenchyma.
Fig., Longitudinal view of the spleen shows a thin, well-defined
line (arrow) due to a peripheral splenic cleft.

14. TECHNIQUE
The spleen is generally best visualized from a high posterolateral
intercostal approach with the patient in the supine Position.
Spleen is seen well from an anterolateral subcostal approach with
the patient in a right lateral decubitus or right posterior oblique
position.
When scanning from a subcostal approach, a deep inspiration is
often helpful

17. CYSTS
A variety of cystic lesions occur in the spleen. Most splenic cysts
result from trauma. They can also arise from earlier infections
and infarcts. Their appearance is similar to that of cysts in other
Organs.
Fig., A, Longitudinal view of the spleen shows a well-defined
anechoic mass (C) in the superior aspect of the spleen. There
are no solid elements and there is detectable enhanced through
transmission.
B, Longitudinal view shows two cysts (C) with peripheral wall
calcification and some posterior shadowing.

20. Hemorrhagic cysts.
A, Magnified view of the spleen shows a well-defined cystic lesion
(cursors) with a fluid-cellular level.
B, Longitudinal view shows a complex cystic lesion (cursors) with
multiple thick septations and low-level internal echoes.

22. Perisplenic cysts can arise from a variety of organs adjacent to
the spleen. The most common are exophytic renal cysts and
pancreatic pseudocysts.
Perisplenic endometriosis. Transverse view of the left upper
quadrant shows the superior aspect of the spleen (S) and
multiple small cystic lesions (arrows) between the spleen and
the diaphragm. Laparoscopic findings confirmed the
diagnosis of endometriosis.

24. TUMORS
Hemangiomas are the most common benign neoplasm of the
spleen, but they are seen on imaging studies much less often
in the spleen than in the liver. They are present in 1% to 14%
of spleens in autopsy studies. They are typically hyperechoic
and homogeneous.
Longitudinal view of the spleen shows a homogeneous
hyperechoic mass (cursors). This mass was found to be
stable over many years, and this behavior is most consistent
with a hemangioma.

26. Lymphangiomas occur more often in children than in adults and
are often subcapsular. They are composed of multiple cystic
spaces that vary in size. When the cysts are large enough,
they will be seen as anechoic spaces (Fig. 8-8), but collections
of very small cysts will appear solid and can be hyperechoic.
Lymphangiomas in different patients. A, Transverse view of the
spleen shows a multicystic mass in the medial aspect of the
spleen in a subcapsular location. B, Longitudinal view shows a
multicystic lesion replacing most of the spleen.

27. The most common malignancy of the spleen is lymphoma. can
have multiple sonographic appearances, including the following:
normal, splenomegaly without focal lesions, unifocal or
multifocal lesions with or without splenomegaly, and miliary
Involvement.
A, Longitudinal view of a patient with lymphoma shows a large,
lobulated hypoechoic mass (cursors).
B, Longitudinal view of a patient with lymphoma shows a well-
defined, spherical very hypoechoic mass (cursors) with slight
increased through transmission.

28. C, Longitudinal view of a patient with lymphoma shows two solid
hypoechoic lesions.
D, High-resolution view of the superficial aspect of the spleen in a
patient with leukemia shows multiple tiny solid hypoechoic nodules
due to leukemic infiltration.

29. SPLENOMEGALY
A large number of processes can result in splenomegaly. To obtain
Splenomegaly due to lymphoma. A, Longitudinal view of the spleen
shows a length of 17.5 cm (cursor 1), consistent with splenomegaly.
The spleen is otherwise normal. B, Transverse view of the porta
hepatis shows bulky periportal adenopathy. Biopsies subsequently
confirmed lymphoma.