Anatomy - American College of...
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Abdomen Imaging Overview Anatomy
Transcript of Anatomy - American College of...
AbdomenImaging Overview
Anatomy
Before You Begin
This module, intended for pre-clinical medical students, is part of the core anatomy teaching series. There should be no prerequisite knowledge necessary for medical students to successfully review and understand this module.
Many of the additional module series in our website build off a strong understanding of human anatomy as it presents in imaging. Please refer back to these anatomy modules if you ever need to review.
If material is repeated from another module, it will be outlined as this text is so that you are aware
Introduction
• The abdomen consists of:• Abdominal Wall
• Upper GI Tract
• Lower GI Tract
• Kidneys and Retroperitoneum
• Inguinal Region
• In this module, we will explore basic abdominal anatomy identifiable with common imaging modalities
Basic Anatomy Overview
Plain Film Radiographs
Abdominal Radiographs• Utilize ionizing radiation to
capture images
• Material density determines the degree of X-ray attenuation, and thus, appearance:
Gas (Air)
Soft Tissue (Water)
Metal
Fat
Bone
Consider Positioning• Remember that gas rises; bowel gas pattern can thereby
indicate patient positioning:
Supine Upright
• Identify density variations to determine tissue interfaces and distinguish organs
Approach to Interpretation
Approach to Interpretation• Trace out the bowel in a segmental fashion (note that not all
segments will be visible, depending on gas distribution)
Stomach
Cecum
Descending Colon
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Liver lobe edge
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R. kidney L. psoas
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Medulla
Minor calyx
Renal pelvis
Papilla
Renal pyramid
Ureter
Cortex
Computed Tomography (CT)
CT Abdomen
• Utilizes ionizing radiation to produce cross-sectional images
• Digital “windowing” can highlight specific tissues
• Note the patient orientation shown to the left
Anterior
Posterior
RightLeft
Lesser Sac
Falciform Ligament
LiverGastrosplenicLigament
Left Subphrenic space
Right Subphrenicspace
Lesser Sac
Gastrohepatic Ligament
Pancreas
Lesser Sac
Peritoneum and Retroperitoneum
Spine
LKAIVC
RK
Spatial Relationships Overview
Lesser Sac
Falciform Ligament
LiverGastrosplenicLigament
Left Subphrenic space
Right Subphrenicspace
Lesser Sac
Gastrohepatic Ligament
Pancreas
Lesser Sac
Peritoneum and Retroperitoneum
Spine
LKAIVC
RK
Spatial Relationships Overview
A. Near midline
Stomach
Colon
Lesser Sac
Pancr
3rd
Duod
Coronary Ligaments
Greater peritonealCavity
Greater Omentum
Liver
“Bare Area”
Diaphram
Triangular Ligament
Left SubphrenicSpace
Gastrophrenic ligament
Lesser SacStomach
Liver
Left Kidney
Pancr.
Greater Omentum
Colon
Greater peritonealCavity
Transverse Mesocolon
Gastrocolic Ligament
B. Lateral Aspect
CT Axial Series
Liver
Gallbladder Stomach
Esophagus
Diaphragm
Hep. flexure
Portal v.
IVC
D. aorta
GB
duodenum
Spleen
jejunum
2nd pt of Duodenum
Stomach
GB
Spleen
L. Gastric A.
Pancreas
Splenic flexure
Liver
Descending duodenum
R. Suprarenal gland
IVC
Portal v.
Splenic v.
jejunum
Splenic V
Splenic A
T. colon Stomach
Common Hepatic A.
Splenic A.
L. Gastric APortal v.
Celiac Trunk
L. Suprarenal gland
2nd part of duodenum
Pancreas
Superior mesenteric a.
IVC
L. Renal v.
Inf. Mes. V.
2nd part of duodenum
Pancreas
Right renal v.
Ureteropelvic Junction
Right Renal A.
L. Renal v.
L. Renal a.
Asc. colonDesc. colon
SMV SMA
Inferior mesenteric a.
Inferior mesenteric v.
Superior mesenteric a. + .v
Terminal ileum
Cecum
L. External oblique
L. Internal oblique
L. Transversus abdominusL. Rectus abdominus
L. Psoas m.
R. ureter
L. Quadratus lumborum m.
CT Coronal Series
Jejunal aa.
R. Colic a
jejunum
Splenic v.
SMA
Pancreas
R. Colic a.
Pancreas
Duodenal sweep
StomachLiver
Gallbladder
Asc. colon
D. colon
Splenic a.
L. hep. A.
R. hep. a.
Cystic a.
CT
SMA
IMA
Prop. Hepatic a.
Sup. Rectal a.
Sigmoidal aa.
ileocolic a.
Colic branch
Ileal branch
L. Gastric a.
Portal v.
Appendix
haustra
Tail of pancreas
Ileocolic v.
L. Renal a.
Splenic a.
Barium Studies
Barium Studies
• Utilize ionizing radiation to image the GI tract after the patient has swallowed contrast (often barium sulfate)
• Approach to interpretation largely utilizes the same principles as abdominal radiographs
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Fundus
Body
Antrum
Pyloric sphincter
Pyloric canal
esophagusRugae
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Pyloric canal
Pyloric sphincter
Superior part duodenum
Descending part duodenum
Inferior part duodenum
Ascending part duodenum
Jejeunum
Jejeunum
Ileum
Ascending colon
Hepatic flexure
Splenic flexureTransverse colon
Descending colon
Sigmoid colon
Cecum
Ileocecal junction
Haustra
ERCPEndoscopic Retrograde Cholangiopancreatography
ERCP• Technique involves concomitant endoscopy and fluoroscopy
• As such, it can be both diagnostic and therapeutic
• Allows physicians to inject contrast into the biliary tree and pancreas, identifying pathologies that may be present
Biliary Tree Anatomy Overview
Body of Gallbladder
Cystic duct
R. Hepatic duct L. Hepatic duct
Common Hepatic duct
Common Bile duct
Hepatopancreatic ampulla
Angiograms
Celiac Trunk Overview
Splenic a.Hepatic artery proper
Gastroduodenal a.
L. Gastric a.
Splenic a.
L. Gastric a.
Common hepatic a.
Gastroduodenal a.
R. Colic a.
Ileocolic a.
Colic br.
Cecal br.
SMA
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Asc. br.
of L. colic a.
desc. br.
of L. colic a.
Sigmoid aa.
Superior rectal a.
L. Colic a.
IMA
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L. Colic a.
IMA
Asc. br.
of L. colic a.
desc. br.
of L. colic a.
Sigmoid aa.
Superior rectal a.
END
