Cross Sectional FINAL REVIEW PDF

WEEK 1 REVIEW LECTURE 1: ABDOMINAL VASCULATURE 3 layers of a blood vessel - Tunica adventitia: outermost layer of the vessel that encapsulates the blood vessel in a thin fibrous wall ‣ Vasa vasorum: the tiny veins and arteries that supply the gre...

WEEK 1 REVIEW LECTURE 1: ABDOMINAL VASCULATURE 3 layers of a blood vessel - Tunica adventitia: outermost layer of the vessel that encapsulates the blood vessel in a thin fibrous wall ‣ Vasa vasorum: the tiny veins and arteries that supply the greater blood vessel itself (necessary for muscle) ‣ Nerves - Tunica media: middle, “meaty” layer of the vessel ‣ External elastic membrane: outer layer of the tunica media ‣ Smooth muscle: inner layer and composes most of the tunica media - Tunica intima: innermost layer of the vessel ‣ Internal elastic membrane: outer layer of the tunica intima ‣ Lamina propria: middle layer of smooth muscle and connective tissue ‣ Basement membrane: additional middle layer of the tunica intima ‣ Endothelium: inner layer of of the tunica intima and the overall innermost layer of the greater blood vessel to psoas major Abdominal arteries anterior lateral to the muscle, LT - spine - The abdominal aorta (AO) ‣ Located in the retroperitoneal cavity anterior and left of the IVC and spine  ‣ Originates from the left ventricle of the heart ‣ Posterior to the diaphragm ✴ The diaphragm divides the AO into the descending thoracic AO and descending abdominal AO ‣ Bifurcates (aka splits) at the umbilicus into the right and left iliac arteries ‣ Normally ≤ 3 cm and tapers into a narrower diameter as it descends ✴ Normal iliac arteries are ≤ 1 cm - Branches of the AO arch (located in the thoracic cavity, not in the abdomen) ‣ 1st branch: Right innominate artery/Brachiocephalic trunk ‣ 2nd branch: Left common carotid artery (CCA) 123 ‣ 3rd branch: Left subclavian artery - Branches of the abdominal AO ‣ Celiac trunk: the 1st branch of the abdominal AO ✴ Originates from the anterior AO 1 - 3 cm below the diaphragm ✴ Separates the proximal and distal abdominal AO ✴ 3 branches: Common hepatic artery (CHA): right side of the celiac trunk (aka right side of the seagull sign) ✓ Borders the superior surface of the pancreas head (aka vessel runs parallel and on top of the pancreas towards the liver)  ✓ Low resistance Doppler waveform ✓ Branches: ➡ Gastroduodenal artery ➡ Right gastric artery ➡ Proper hepatic artery (further divided into…) ★ Right and left hepatic arteries ★ Cystic artery (technically a branch of the right hepatic artery) Splenic artery (SA): left side of the celiac trunk (aka left side of the seagull sign) * 4-6 mm in diameter ! ✓ Tortuous in nature (twisted) with numerous branches ✓ Borders the superior surface of the pancreas body and tail (aka vessel runs parallel to and on top of the pancreas towards the spleen) ✓ Low resistance Doppler waveform Left gastric artery: limited visualization with ultrasound due to its very small size celiac before artem teaching and into CHA , LT gastric , SA - Normally 7 mm in diameter Low resistance Doppler waveform in the trunk and branches ✴ Objective: supplies blood to the stomach, liver, spleen, and small intestine  CHA = liver SA = spleen Left gastric = stomach and small intestines ‣ Superior mesenteric artery: the 2nd branch of the abdominal AO ✴ Originates from the anterior AO 1 - 2 cm below the celiac trunk ✴ Runs parallel to the anterior AO (aka vertical) and posterior to the pancreas ✴ Normally 6 mm in diameter ✴ Doppler waveform depends on fasting state Fasting = high resistance = vessels constricted to decrease blood flow Non-fasting = low resistance = vessels dilated to increase blood flow ✴ Objective: supplies blood to the small intestine, cecum, and ascending and transverse colon ‣ Right and left renal arteries: the branches of the abdominal AO that supply the kidneys respectively ✴ Vessels originate from the lateral walls of the AO respectively just below the SMA  Right vessel is longer than the left due to proximity to the right kidney from the AO and the fact that it has to travel around the IVC ✴ Right renal artery is often seen superior to the IVC ✴ Left renal artery is more superior than the right This is because the liver, which is very large in size, is on the right side of the body and forces the right kidney to be in a more inferior position than the left ✴ Normally 4 - 5 mm in diameter ✴ Branches into 4 or 5 smaller arteries prior to reaching the hilum of the kidney ✴ Low resistance Doppler waveform Vessels are always dilated because they always require blood ✴ Objective: supplies blood to each kidney respectively ‣ Gonadal arteries: the branches of the abdominal AO that supply the reproductive organs ✴ Difficult to visualize with ultrasound due to small size ✴ Arise from the anterior lateral aspect of the AO, inferior to the renal arteries following the psoas muscle ‣ Inferior mesenteric artery: the last branch of the abdominal AO before it bifurcates into the right and left iliac arteries  ✴ Originates from the anterior lateral side of the AO, 4 cm away from the bifurcation (aka somewhere between the renal vessels and the iliac bifurcation) ✴ Limited visualization on ultrasound due to small size ✴ Normally 3 mm in diameter ✴ High resistance Doppler waveform ✴ Objective: supplies blood to the descending colon, sigmoid colon, and rectum Diaphragmatic crus: a dome-shaped muscular structure that crosses the &TCrusSeei a trV & RTCVs ea. &. midline posterior to the IVC and anterior to the AO - Often mistaken for the right renal artery (RRA)! ‣ The RRA is anterior to the right crus diameter : 11 5 cm Normal Abdominal veins. e - Inferior vena cava (IVC): ‣ Located in the retroperitoneal cavity anterior to the spine, posterior to the intestines and the caudate lobe of the liver, and to the right of the AO ‣ Passes through the diaphragm and terminates in the right atrium of the heart ‣ Formed by convergence of the common iliac veins ‣ Branches of the abdominal IVC: ✴ Hepatic veins: the 1st branches of the IVC from the heart  Located just superior to the renal veins Hepatofugal flow: blood moves away from the liver ✓ Hepatopedal flow: blood moves towards the liver 3 branches: M RT LT ✓ Right branch: drains the right lobe of the liver and divides the right lobe into anterior and posterior portions and right ✓ Middle/intermediate branch: drains the caudate lobe of the liver and divides the caudate lobe into right and left portions ✓ Left branch: drains the left lobe of the liver and divides the left lobe into medial and lateral segments Normally 4 - 7 mm in diameter ✓ Increases in diameter as vessels get closer to the IVC Pulsatile Doppler waveforms Objective: empty blood from the liver into the IVC ✴ Renal veins: the 2nd branches of the IVC from the heart Located just inferior to the renal arteries, with the LRV being longer than the RRV due to proximity ✓ The LRV is seen anterior to the abdominal AO LRV receives blood from gonadal veins and suprarenal veins before terminating into the IVC Normally 4 - 6 mm in diameter  found only arteries - in No pulsatility in Doppler waveforms Objective: drain deoxygenated blood from the kidneys back into the IVC ✴ Superior mesenteric vein (SMV): joins the splenic vein to form the PV Drains the proximal portion of the large intestine and portions of the small intestine Blood flows towards the head posterior to the pancreas neck and anterior to the uncinate process ✴ Splenic vein (SV): joins with the SMV to form the PV Runs along the posterior border of the pancreas Does not drain directly into the IVC ✓ Joins with the inferior mesenteric vein (IMV) first before joining the SMV to form the PV Normally 4 - 6 mm in diameter ✴ Gonadal veins: the next branches of the abdominal IVC after the renal veins Right gonadal vein: located lateral and inferior to the RRV and drains directly into the IVC Left gonadal vein: technically a branch of the LRV, it doesn’t drain directly into the IVC  ✴ Common iliac veins: the lowest branches of the abdominal IVC that splits - The portal venous system ‣ Portal veins wear pajamas! ✴ Appear on a 2D image with hyperechoic borders, which is how we are able to distinguish them from hepatic veins! ‣ Main portal vein (MPV or PV): originates from the junction of the SMV and SV, posterior to the pancreas and just to the right of the midline ✴ Bifurcates at the porta hepatis into right and left portal veins ✴ Normally < 13 mm in diameter & portal triad = proper hepatic Common art. bile duct + PV + ‣ Right portal vein (RPV): runs centrally and horizontally in the right lobe of the liver ✴ Bifurcates into anterior and posterior branches that divide the right lobe of the liver into anterior and posterior segments ✴ Larger than the left portal vein ‣ Left portal vein (LPV): runs in the left lobe of the liver ✴ Branches divide the left lobe of the liver into medial and lateral segments RT 6 mm, must R/O appendicitis ✴ Sonographic appearance of the appendix SAG = finger-like projection TRV = bullseye  burearea sac lesser liver lesser entum stomach pancreas duodenum transverse color greatertum  supracolic transverse compartment color descending color ascending colon infracolic compartment LT paracolic gutter RT paracolic gutter  fimbrial utems ovary anterior cul-de-sac rectum urinary bladder posterior cul-de-sac public is symphys vaginalal space a o anus wrethra