Citation, DOI & article data
The spleen is an organ of the hematological system and has a role in immune response, storage of red blood cells and hematopoiesis.
The spleen is a wedge-shaped organ lying mainly in the left upper quadrant (left hypochondrium and partly in the epigastrium) and is protected by the left 9th to 11th ribs. It is soft, highly vascular and dark purple in color.
Size and weight vary from person-to-person but on average is around 2.5 cm thick, 7.5 cm broad and 12.5 cm in length. For pediatric measurements, see the article spleen size (pediatric)
The spleen has two poles (superior and inferior), three borders (superior, inferior and intermediate) and two surfaces (diaphragmatic and visceral). It is enclosed by a thin capsule, which is easily ruptured.
The spleen is completely covered by peritoneum, except at the hilum, which forms a number of ligaments 6,7:
- gastrosplenic ligament
- attaches the spleen to the left kidney
- contains splenic artery and vein and the pancreatic tail
- diaphragmatic surface (superoposteriorly): dome of the left hemidiaphragm, left 9th to 11th ribs
- visceral surface
- pancreatic tail - medial
- left kidney and adrenal gland - posteromedial
- stomach - anteromedial
- splenic flexure of the transverse colon - inferior
- from splenic hilar lymph nodes to retropancreatic lymph nodes, then draining to celiac lymph nodes
- wandering spleen
- splenogonadal fusion
- retrorenal spleen
- bilobar spleen 11
- splenic cleft: may mimic traumatic laceration
- best assessed in the supine, right lateral position with the left arm placed behind the head
- visualized best obliquely in the 9th or 10th intercostal spaces
- echogenicity usually higher when compared to the liver, but may be iso- or hypoechoic
The splenic parenchyma should be assessed in the portal venous phase as inhomogeneous splenic enhancement (zebra or psychedelic spleen) seen in the arterial phase can mimic a splenic laceration or contusion 5.
Embryologically, the spleen forms from several splenic buds that fuse together within the dorsal mesentery of the foregut (dorsal mesogastrium) 10.
- 1. Rabushka LS, Kawashima A, Fishman EK. Imaging of the spleen: CT with supplemental MR examination. Radiographics. 1994;14 (2): 307-32. doi:10.1148/radiographics.14.2.8190956 - Pubmed citation
- 2. Romer T, Wiesner W. The accessory spleen: prevalence and imaging findings in 1,735 consecutive patients examined by multidetector computed tomography. JBR-BTR. 2012;95 (2): 61-5. Pubmed citation
- 3. Robertson F, Leander P, Ekberg O. Radiology of the spleen. Eur Radiol. 2001;11 (1): 80-95. Pubmed citation
- 4. Rolfes RJ, Ros PR. The spleen: an integrated imaging approach. Crit Rev Diagn Imaging. 1990;30 (1): 41-83. Pubmed citation
- 5. Boscak AR, Shanmuganathan K, Mirvis SE et-al. Optimizing trauma multidetector CT protocol for blunt splenic injury: need for arterial and portal venous phase scans. Radiology. 2013;268 (1): 79-88. doi:10.1148/radiol.13121370 - Pubmed citation
- 6. Surgical anatomy and technique. Springer. ISBN:0387095152. Read it at Google Books - Find it at Amazon
- 7. Drake. Gray's basic anatomy. Churchill Livingstone. ISBN:1455710784. Read it at Google Books - Find it at Amazon
- 8. Donnelly LF, Foss JN, Frush DP, Bisset GS. Heterogeneous splenic enhancement patterns on spiral CT images in children: minimizing misinterpretation. Radiology. 210 (2): 493-7. doi:10.1148/radiology.210.2.r99fe16493 - Pubmed
- 9. Standring S, Gray H (2008). Gray's anatomy: The anatomical basis of clinical practice. Edinburgh: Churchill Livingstone/Elsevier
- 10. Sharma M, Madambath JG, Somani P, Pathak A, Rameshbabu CS, Bansal R, Ramasamy K, Patil A. Endoscopic ultrasound of peritoneal spaces. (2017) Endoscopic ultrasound. 6 (2): 90-102. doi:10.4103/2303-9027.204816 - Pubmed
- 11. Ali H. Bilobed Spleen: An Extremely Rare Imaging Finding. BJR Case Rep. 2017;3(4):20170021. doi:10.1259/bjrcr.20170021 - Pubmed