The SPLEEN HHHoldorf Normal Anatomy - PowerPoint Presentation

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The SPLEEN HHHoldorf

Normal Anatomy

Accessory Spleen

Splenic Calcifications

Splenic Cysts

Benign Splenic tumors

Splenic abscess

Splenic Infarct

Splenomegaly

Splenic Artery Aneurysm

Visceral Heterotaxy (polysplenia /Asplenia

Splenic TraumaSlide2

Ultrasound TechniqueThe normal spleen is difficult to image, as it is almost totally surrounded by ribs and gas-containing organs.The recommended technique is to place the patient in a right lateral Decubitus position and scan with a 3.5 to 5 MHz, medium focus transducer through the lower inter-costal spacers.

Coronal long axis and transverse are routine views.Slide3

Right Lateral Decubitus Position for imaging the spleenSlide4

Anatomy and Normal ultrasound appearanceThe spleen is an important organ located in the left upper quadrant (LUQ). It is located posterior to the stomach and superior and lateral to the left kidney. In its normal position, it is usually not clinically palpable. Vessels, lymphatics and nerves enter and leave the splenic hilum, which is located medially. The tail of the pancreas also sits in the region of the splenic hilum just anterior to the kidney. Slide5

Anatomy and Normal ultrasound appearance, cont…The spleen is seen as a structure with uniform echo texture and moderate echogenicity and no visible parenchymal vessels.

Splenic vessels may be seen in the splenic hilum.

The spleen is considered to be slightly more echogenic than the liver.

The normal spleen measures less than 12 cm in length in the carnio-caudal (long axis) dimension.

The appearance of the spleen has been known to be called Crescent. Slide6

Crescent moonSlide7

Normal AnatomyThe spleen is a peritoneal organ located in the left upper quadrant between the stomach and the diaphragm. It is the largest lymphoid organ that filters damaged cells, microorganisms and particulate mater. It also delivers antigens to the immune system.Slide8

The parenchymal echogenicity of the spleen varies. The average adult spleen measures:12 cm – longitudinal8 cm – transverse4 cm – thicknessSlide9

SplenomegalySplenomegaly is indicated with a longitudinal measurement > 12 cm or if the spleen is inferior to the lower pole of the left kidney.Slide10

SplenomegalyPortal hypertension, due to cirrhosis, is the most common cause of congestive splenomegaly in adults. Other reasons include:

Viral infections

Bacterial infections

Rheumatoid arthritis

Hemolytic anemia

Leukemia

Lymphoma

Congestive heart failure

Sickle cell anemiaSlide11

Splenomegaly cont…The spleen is located in the LUQ, so when it enlarges, it extends in the anterior, medial and inferior directions.Polycythemia Vera- blood disorder resulting in uncontrolled RBC production causing hyperviscosity and hypercoagulation. Polycythemia vera may be the cause of

Splenomegaly

Budd-Chiari Syndrome

Portal vein Thrombosis

Splenic InfarctsSlide12

SplenomegalyDiffuse splenomegaly is the most common feature and manifestation of splenic disease.The spleen may be enlarged in a variety of conditions including liver disease, blood disorders, infections, and neoplastic involvement.

With diffuse disease, the spleen may be less echogenic, more echoic, or have the same echogenicity as normal.Slide13

Splenomegaly cont…Portal hypertension secondary to alcoholic cirrhosis is the most common cause of splenomegaly in adults.In certain conditions, such as malignant lymphoma and polycythemia vera (a blood disorder in which the bone marrow makes too many red blood cells), the spleen may be massively enlarged and even extend into the pelvis.Slide14
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SplenomegalySlide16

SplenomegalySlide17
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Splenomegaly: 14.3 cm Slide19

Normal AnatomyThe normal liver usually does not touch the spleen. If the left lobe is enlarged, it may extend into the left upper quadrant anterior to the spleen. The left lobe of the liver is also seen anterior to the spleen during the third trimester of pregnancy.Slide20

The stomach, left kidney, pancreas and splenic flexure of the colon is located on the visceral surface of the spleen.The fundus of the stomach and lesser sac are medial and anterior to the splenic hilum. The tail of the pancrease is located posterior to the stomach and lesser sac as it approaches the splenic hilum.Slide21

The left kidney lies anterior an medial to the spleen. The pancreatic tail is located anterior to the upper pole of the left kidney in the splenic hilum. Slide22
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Sagittal Image of a normal SpleenSlide24

Crescent shaped Trans SpleenSlide25

Sagittal measurement of a normal spleenSlide26

Splenic HilumSlide27

Accessory SpleenDeveloped in embryology, an accessory spleen is a small nodule of splenic tissue found apart form the main body of the spleen. Found in approximately 10% of the population, it is most commonly found in the splenic hilum and adjacent to the tail of the pancreas.

May be mistaken for Splenomegaly or a focal mass. Slide28

An accessory spleen is a normal variant that is commonly found. It may be confused with enlarged lymph nodes around the spleen, or a mass in the tail of the pancreas.The majority of accessory spleens are easy to recognize sonographically as small rounded masses, less than 5 cm in diameter. They are located near the splenic hilum and have identical echogenicity to the adjacent spleen.Slide29

Accessory SpleenSlide30

Accessory SpleenSlide31
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Accessory SpleenSlide33

Splenic CalcificationsGranulomas are focal lesions resulting from previous infections. They are seen as focal bright echogenic lesions, with or without shadowing.Histoplasmosis and tuberculosis are the most common causes of granulomas.

Granulomas are also found in the liver and lungs.

Other splenic calcifications can be associated with

Splenic artery or splenic artery aneurysms

Splenic infarct (as they evolve)Slide34

PathologySonography is useful to evaluate both focal and diffuse diseases of the spleen. Nuclear Medicine imaging may be useful in specific situations and ultrasound is often requested to characterize a focal defect seen on the radio-isotope liver-spleen scan.Slide35

Loculated Splenic CystSlide36

Splenic AbscessABSCESS- Splenic abscesses are most commonly caused by spread of adjacent infections (subphrenic, pancreatic, or perinephric abscesses). Immunocompromised patients are susceptible to splenic abscesses. Sonographically, the abscess is often a mixed lesion similar to a hematoma. Others may be anechoic or have low levels of internal echoes.Slide37

Splenic Abscess cont…Splenic infection is associated with general abdominal sepsis.Damaged splenic tissue is a good culture medium, susceptible to infection, with filtered bacteria available in the spleen.

Sonographically, splenic abscesses are seen as complex cystic lesions. The presence of gas may produce echogenic foci with an associated reverberation (comet-tail) artifact.Slide38

Splenic AbscessSlide39

Splenic AbscessSlide40

Pathology cont…Infarcts: IV narcotic drug abuse leading to bacterial endodcarditis is a major cause of splenic infarction and its complication: Splenic abscess.

Embolic fragments from infected heart valves are carried in the bloodstream and lodge in the spleen causing an infarct which may heal or progress to an abscess. Infarcts may also be caused by leukemia and pancreatic cancer.Slide41

Splenic InfarctSplenic infarcts are common in patients with bacterial endocarditis and splenic artery aneurysms.They present as a peripheral wedge-shaped hypoechoic lesion.

The sonographic appearance of an infarct will change over time, as do hematomas. The initial ischemia and edema will appear as a hypoechoic wedge of tissue. With necrosis and liquification, the area will appear anechoic and ultimately will calcify.Slide42

Pathology – infarcts- cont…Sonographically, fresh infarcts are well defined, hypoechoic wedge-shaped focal lesions. The base of the wedge is towards the capsule and the apex towards the hilum. With time, the lesion shrinks and becomes more echogenic.

Complete healing may occur.Slide43

InfarctSlide44
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Splenic InfarctSlide46

TraumaSplenic trauma may result in a parenchymal or subcapsular hematoma or splenic laceration with associated hemoperitoneum.

Clinical symptoms depend on the extent of blood loss.

If the splenic capsule is intact, a subcapsular hematoma may be seen as a peripheral crescent-shaped collection.

If the spleen is lacerated, a hemoperitoneum will occur which may be located in the LUQ or extend into the other peritoneal compartments, including the paracolic gutters, pelvis, and right side. Conservative management is preferred to spenectomy if the patient is clinically stable. Slide47
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Lacerated SpleenSlide49

Intraperitoneal bleedRuptured Splenic capsuleSlide50

Ruptured Splenic CapsuleSlide51

Wandering SpleenA condition in which the ligaments that hold the spleen in place weaken, causing the spleen to be misplaced, sometimes even into the pelvis.Symptoms include an enlargement in the size of the spleen.Slide52
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Wandering spleen found in the pelvisSlide54

Splenic artery aneurysmTypically, a calcified circle is seen in the left upper quadrant on an x-ray and a splenic artery aneurysm is suspected.Sonographically, a splenic artery aneurysm may appear as a cystic mass, or if calcified, a hyperechoic shadowing foci in the area of the splenic artery. The artery should be traced from the celiac axis along the anterior aspect of the pancreatic tail to the splenic hilum. Filling the stomach with water may aid in visualizing the pancreatic tail.Slide55

Visceral Heterotaxy (Polysplenia/Asplenia) Heterotaxia: or situs ambiguous, is the disruption in the development of the normal asymmetric arrangement of abdominal organs and vessels.

Heterotaxia

is a generic term defining the mis-arrangement of abdominal structures.

Polysplenia and asplenia

are two classifications of heterotaxia.Slide56

Sonographers encounter heterotaxia in the neonate patient. The initial presentation is with symptoms of congenital heart disease or jaundice due to biliary tract abnormalities.Polysplenia: defined as bilateral left-sidedness, is associated with the following abnormalities:

Multiple LUQ spleens

Biliary atresia / absent gallbladder

Intestinal malrotation

Azygous continuation of interrupted IVC

Cardiac defectsSlide57

Asplenia, defined as bilateral right-sidedness, is associated with the following abnormalities:Absent spleenMidline liver and gallbladderIntestinal malroatationReversed positions of aorta and IVC

Cardiac defectsSlide58

Liver spleen scanNuclear MedicineSlide59

Liver Spleen ScanNuclear MedicineSlide60

Homework:1. Submit an image of a normal spleen in Longitudinal and Transverse views.2. Submit an image of a splenic abscess.

3. Submit an image of a splenic infarct.

4. Submit an image of a splenic laceration with associated hemoperitoneum.

5.Submit an image of a wandering spleen.

6. Submit an image of an accessory spleen.Slide61

What are four functions of the spleen?A. breakdown of hemoglobinB. Formation of bile pigmentsC. Formation of antibodies

D. A reservoir for bloodSlide62

Name five structures that appear as cystic splenic masses.1. Cystic degeneration of infarcts of hematomas.2. Cysts associated with adult polycystic kidney disease.

3. Parasitic cysts of the spleen (echinococcal cysts)

4. Epidermoid cysts of the spleen.

5. Pancreatic pseudocystsSlide63

Describe the sonographic appearance of a splenic infarct.The typical appearance of a splenic infarct is a peripheral wedge-shaped hypoechoic lesion Slide64

What type of hematoma is the result of splenic trauma in which the splenic capsule remains intact?An intra-parenchymical or sub-capsular hematoma occurs with splenic trauma in which the splenic capsule remains intact.Slide65

What type of hematoma is the result of splenic trauma in which the splenic capsule ruptures?A peri-splenic or intra-peritoneal hematoma occurs with splenic trauma in which the splenic capsule ruptures.Slide66

Splenic TraumaIntraparenchymal or subcapsular hematomas result when the splenic capsule remains intact (DOES NOT RUPTURE).Slide67

Splenic Trauma cont…Perisplenic or intraperitoneal hematomas results with capsule RUPTURE. After capsule rupture, fluid is typically demonstrated to be loculated around the spleen, although blood may spread within the peritoneal cavity.Slide68

FASTFocused Assessment with Sonography for Trauma (FAST) is utilized in the emergency department to document the presence of free fluid in the peritoneal cavity.The FAST exam also allows analysis for possible hemopericardium, hemothorax, solid organ damage, and retroperitoneal injury.

2007 AIUMSlide69

The ultrasound appearance of intraperitoneal blood depends on the age, amount an physical state of the clot.The timing of blood coagulation is not fully understood and acute bleeds may have various sonographic appearances.Most medical professionals assume that hemoperitoneum will appear anechoic, although, one may see an irregular marginated, echogenic mass that may mimic that of an enlarged spleen.Slide70

In a patient with a history of splenic rupture or surgery, splenic cells may implant throughout the peritoneal cavity (autotransplanatation) resulting in a ectopic spleen.This occurrence is called POSTTRAUMATIC SPENOSIS. Spenosis is often asymptomatic and may mimic other pathologies.