ABD-notes PDF Study Guide to Abdominal Ultrasound

Study guide to Abdominal/General Ultrasound Registry Review Melessa Cizik RDMS, RVT myultrasoundtutor.com 2023 edition Table of Contents Abdomen Introduction to anatomy and disease ………………………………………….……..….1 Liver..……………………………………………………………..….....

Study guide to Abdominal/General Ultrasound Registry Review Melessa Cizik RDMS, RVT myultrasoundtutor.com 2023 edition Table of Contents Abdomen Introduction to anatomy and disease ………………………………………….……..….1 Liver..……………………………………………………………..…..……………………. 4 Gallbladder and Biliary.……………………………………………..………………….. 14 Pancreas ………………………………………………………………………………….. 22 Spleen …………………………………………………………………………………….. 26 Renal and Urinary ……………………………………………………………………….. 29 Adrenal …………………………………………………………………………………… 45 Abdominal Vascular …………………………………………………………………….. 49 Miscellaneous Abdomen Gastrointestinal …….……………………………………………………………………. 54 Chest and Retroperitoneum ……………………………………………………….…… 57 Small Parts Thyroid and Neck.…………………………………………………………………..…… 59 MSK and Super cial ……………………….……………..……………………………… 64 Testicular..………………………………………………………………………………… 67 Prostate.………………………………………………………………………………..… 74 Physics Review.………………………………………………………..…………….……..… 76 fi  Abdomen Registry Review Study Guide Introduction to Abdominal Imaging Important things when learning normal anatomy and physiology Location in relation to other organs Relational anatomy Parenchymal divisions / components Landmarks Anterior/superficial = towards front (closer to top) Posterior/deep = towards back (closer to bottom) Vasculature Superior/cephalad = towards head Size and appearance Inferior/caudal = towards feet Medial = closer to middle Variants Lateral = closer to sides Basic function (don’t go crazy) Proximal = closer to origination Distal = closer to termination Sagittal Transverse Basic Abdominal Anatomy Peritoneum = closed sac containing major internal organs Gallbladder Liver Intraperitoneal “inside” the peritoneum. The intraperitoneal GLOSSS organs are covered by a visceral peritoneum and parietal peritoneum. Ovaries Parietal is outer sac. Visceral is the organs “skin” Stomach Spleen Greater sac = larger space Some bowel Lesser sac = AKA omental bursa, between pancreas and stomach. Not for Distribution 1 of 78  Abdomen Registry Review Study Guide Intraperitoneal cavities Spaces that can collect fluid. Ascites is free fluid found in the intraperitoneal cavities Exudate is malignant ascites and transudate is benign FAST scan Focused Assessment with Sonography for Trauma Looking for free intraperitoneal uid or hemoperitoneum in trauma pt ABDOMEN PELVIS Subphrenic : inferior to diaphragm. Between Retropubic space: anterior to bladder aka diaphragm/liver and diaphragm/spleen space of Retzius Subhepatic : inferior to liver. Right posterior Anterior CDS : between bladder and uterus in subhepatic AKA Morison’s pouch (Liver/Kid) females. Doesn’t exist in males Lesser sac : between pancreas and stomach Posterior CDS : between uterus and rectum in Paracolic gutters : lateral sides of abdomen, females. Between bladder and rectum in next to colon males Retroperitoneum Retroperitoneal organs are under the peritoneum and these organs are covered anteriorly by peritoneum. Anterior pararenal space: Pancreas, duodenum, ascending and descending colon, lymph Perirenal space: Kidney, adrenal glands, ureter Posterior pararenal space: Fat Great vessel compartment: IVC, aorta, lymph nodes Not for Distribution 2 of 78 fl  Abdomen Registry Review Study Guide Intro to Abdominal Pathology Pathology categories Diffuse All over, throughout organ. Affecting organ cells = affect organ’s function = abn LABS Most likely to have elevated organ function tests and symptoms of poor organ function Focal benign Cysts/tumors. Do not necessarily affect organ function = asymptomatic Exception: functional endocrine tumors. If produce hormone, then will show symptoms of too much of that hormone Infections Acute -itis or abscess = ACTIVE infection = fever, leukocytosis (elevated WBC), pain Chronic -itis = no symptoms of infection. Now show organ damage (see diffuse) Obstruction Organs with ducts or collecting systems can have blockages (GB, biliary, pancreas, urinary) Pain + may have elevated labs/enzymes (whatever is backing up) Sono = dilated tubes above (proximal to) the blockage Trauma Hemorrhage, hematoma, rupture, laceration, fracture = all bleeding Dec hematocrit or hemoglobin, dropping BP, hx of trauma or surgery Cancer Symptoms vary. Most commons, risk factors, tumor markers, invasion Not for Distribution 3 of 78  Abdomen Registry Review Study Guide Liver Facts: Intraperitoneal (except for bare area) Covering = Glisson Capsule 3 main lobes = right, left, caudate Processing plant = metabolizes the good stuff, gets rid of the bad, makes bile Portal triads = portal vein, hepatic artery, bile duct (go to hepatocyte) Anatomy Intersegmental/hepatic = between segments Separates segments: Fissures, hepatic veins, ligaments, GB Intrasegmental/hepatic = inside segments/liver Do NOT separate: Portal veins, bile ducts, hepatic artery Method of division: Couinaud classification (diagram right) RT Anterior / Posterior RT Anterior / LT Medial LT Medial / LT Lateral Right hepatic vein Middle hepatic vein Left hepatic vein Rt intersegmental ssure Main lobar ssure Lt intersegmental ssure GB Falciform ligament Ligamentum teres Not for Distribution 4 of 78 fi fi fi  Abdomen Registry Review Study Guide Caudate lobe: Segment 1 (Couinaud) separated from left lobe by ligamentum venosum and bordered posteriorly by IVC Ligaments Echogenic band on sono. Ligaments always there. Ligamentum = ligaments formed by closure of blood vessels. Ligamentum venosum: in utero = ductus venosus Ligamentum teres AKA round ligament: in utero = umbilical vein. Inside falciform ligament Vasculature Supply: Portal vein and hepatic artery. 70% of blood supplied by MPV. MPV and proper hepatic artery enter at porta hepatis. Both are HEPATOPETAL / towards liver. PV steady, minimally phasic. HA low resistance Both are intrasegmental. Branches match segments. Drainage: Hepatic veins. Drain into Rt atrium HEPATOFUGAL /away from the liver and pulsatile HV are intersegmental. Between and split segments Not for Distribution 5 of 78  Abdomen Registry Review Study Guide Variants Reidel’s lobe: extension of rt lobe over rt kidney. May cause “false-positive”. To distinguish from hepatomegaly, look at left lobe for enlargement Papillary process: inferior extension of the caudate lobe Sonography Normal up to 15cm along mid-hepatic line (dome to inf tip) Slightly echogenic compared to kidney MPV diameter ≤ 13mm Pathology Symptomatic Diffuse / Infection / Cancer DIFFUSE Liver disease and labs Hyper = increased Diffuse disease = think function! Liver enzymes >> ALT, ALP, AST Hypo = decreased ALT = Alanine transaminase -emia = referring to ALP = Alkaline phosphatase blood AST = Aspartate transaminase Bilirubin… When elevated (Hyperbilirubinemia) = JAUNDICE! Basically it’s a waste product of hemolysis, then goes to liver for processing into something useful (bile). The liver does this by conjugating it. Pre-liver = unconjugated. Liver and after = conjugated Indirect (Unconjugated) = Not yet gone through the liver. RBC hemolysis Direct (Conjugated) = Acute liver disease / Hepatitis / Biliary obstruction Total = Usually liver disease/failure Progression of liver disease determines severity of symptoms and labs Fatty (hepatic steatosis) >> may lead to chronic steatohepatitis > chronic disease/cirrhosis Cirrhosis >> liver cell death / fibrosis >> portal hypertension / varices Not for Distribution 6 of 78  Abdomen Registry Review Study Guide Fatty liver infiltration AKA hepatic steatosis Most common diffuse liver disease. Most likely reason for elevated LFTs. Hepatocytes (liver cells) fill with fatty deposits. May also be sign of metabolic syndrome that can lead to steatohepatitis > chronic liver disease and fibrosis, etc Clinical: Elevated LFTS, no symptoms Sono: echogenic/dense, poor thru transmission (high attenuation), poor visualization of vasculature Focal fatty infiltration: Focal echogenic area. Patch of fatty liver. (No mass effect) Focal fatty sparing: Focal hypoechoic area. Patch of normal liver. Most common location: next to GB/porta hepatis (No mass effect) Cirrhosis Liver cell death and fibrosis/liver failure. Most common cause is alcoholism. Clinical: Poor liver function symptoms = elevated LFTs, jaundice (elev total or direct bilirubin), fatigue, weight loss, diarrhea Sono: heterogeneous/coarse texture, small right lobe, enlarged caudate lobe, nodular surface, ascites Nodular surface best eval with higher frequency linear array. Micronodular: smaller nodules when caused by alcoholism Macronodular: >1cm nodules when caused by hepatitis Sequela / Progression of disease Portal hypertension and increased risk of HCC *** eval next: signs of portal hypertension, portal vein thrombosis, and HCC Not for Distribution 7 of 78  Abdomen Registry Review Study Guide Portal Hypertension Most common cause is cirrhosis. Increased pressure on portal system, redirecting blood flow AWAY from liver. Blood flow can only flow into lower pressure. When pressure of liver disease increases too much, resists flow coming into it. Flow drawn to other lower pressure channels. Blood backs up into veins that normally drain into the PV = splenic vein, coronary (lt gastric) vein. These will dilate and form varices or venous collaterals. Clinical: SAME as advanced cirrhosis + may have: caput madusa (superficial abd veins) and GI bleeding Sono: Hepatofugal PV flow, dilated MPV >13mm, abdominal varices = dilated venous collaterals near spleen, stomach, and esophagus, abnormal splenic vein flow, splenomegaly, recanalized paraumbilical vein Treatment: TIPSS transjugular intrahepatic portosystemic shunt Communication or bridge between PV and HV to decompress the portal vein and normalize flow direction. Rt portal vein (prox) > Rt hepatic vein (dist) If successful, flow will be hepatopetal at proximal anastomosis (RPV) and hepatofugal at distal anastomosis (RHV) Not for Distribution 8 of 78  Abdomen Registry Review Study Guide Portal vein compression / thrombosis Obstruction of PV is most commonly caused by tumors or lymphadenopathy. Thrombosis may be caused by increased liver resistance (HCC, mets, portal hypertension) or increased clotting factors (pregnancy, oral contraceptives, surgery). Clinical: Pain, elevated LFTs, hypovolemia, nausea, vomiting Sono: Thrombosis of PV, cavernous transformation Leads to cavernous transformation = periportal collaterals. Small vessels surrounding the portal vein to reroute the blood around the clot towards the liver. Different than portosystemic collaterals! Portal htn collaterals reroute the blood AWAY from the liver. Cavernous transformation is rerouting the blood back INTO the liver. Budd-Chiari Syndrome Occlusion of hepatic veins and possibly IVC. Leads to liver congestion and eventual liver necrosis, caudate lobe enlarges to compensate (Caudate drains directly into IVC) Clinical: Elevated LFTs Sono: Hepatomegaly, enlarged caudate lobe, absent flow hepatic veins Infection = acute hepatitis or abscess Differences between acute hepatitis and abscess. Hepatitis is a DIFFUSE infection so LFT’s will always be abnormal. Abscess is FOCAL = LFTs may be normal Diffuse labs + fever = Whole organ infection “acute -itis” Fever + focal finding = Abscess Not for Distribution 9 of 78  Abdomen Registry Review Study Guide Hepatitis Most common Hep A and B. Hep C is most likely cause of needing liver transplantation -itis= inflammation or infection. Initially will be acute, may become chronic if damages the liver. Acute -itis means active infection. Solid organ acute -itis usually are clinical diagnosis. Acute hepatitis Most common acute: Hepatitis A (fecal-oral route) Clinical: Fever, non-obstructive jaundice (elevated direct bilirubin), elevated LFTs Sono: Initially normal ** may be clinical dx only When sono signs…hepatomegaly, hypoechoic, starry sky sign “Starry sky” sign Periportal cuf ng Inc echogenicity of portal triads Chronic hepatitis Most common chronic: Hepatitis C (bodily fluids). Clinical: No signs of infection. Only evidence of decreased liver function (see cirrhosis) Sono: May have signs of fibrosis or cirrhosis Abscesses Clinical: infection symptoms, fever, pain, leukocytosis Sono: All may be similar. Focal, complex cyst. Look for these differences in clinical or sonographic…. Hydatid Amebic Pyogenic Candida/Fungal Echinococcal Parasite Parasite from water Pyo = Pus / Bacteria Candida albicans Water-lily sign / Daughter GI rst = diarrhea From other infection = Immunocompromised pt cysts / Membranes HX of -itis / Surgery / Bx Cancer, transplant, HIV ↓ ↓ ↓ Target or halo multiples ↓ Not for Distribution 10 of 78 fi fi  Abdomen Registry Review Study Guide FOCAL masses Benign/non-endocrine = asymptomatic Malignant = symptomatic Cysts Benign and mostly asymptomatic. Associated with PKD (polycystic kidney disease). May have pain if hemorrhagic. Sono: anechoic, complex with posterior enhancement Cavernous hemangioma Most common benign liver tumor. Echogenic solid mass Hepatocellular Adenoma Associated with oral contraceptives. Varied, may be echogenic Lipoma Made of fat. Hyperechoic Focal Nodular Hyperplasia 2nd most common benign liver tumor. “Stealth lesion” because it may be isoechoic to liver tissue. Central scar with vascularity. Look for “mass effect” Hematoma “Bleed” from trauma or surgery. Intraparenchymal hematoma: within the organ/liver. More focal appearing Subcapsular: around the liver, just under the Glisson capsule. Like “free fluid” Clinical: Trauma or Biopsy Hx, decreased hematocrit, pain Sono: Anechoic to echogenic depending on age Not for Distribution 11 of 78  Abdomen Registry Review Study Guide Cancer Weight loss, fatigue, abnormal labs and jaundice if obstructive but not always Hepatomegaly Hepatocellular Carcinoma - HCC aka hepatoma. Most common primary liver cancer. Increased risk = chronic liver disease, cirrhosis, hepatitis. Tumor marker = elevated AFP (alphafetoprotein) Sono: usually solitary, hypoechoic mass, ascites Metastasis Most common cancer found in liver. Multiple masses. Lung, colon, breast most common sources. The liver is the most common location for mets Clinical: possible abnormal LFTs, pain, jaundice Sono: multiple masses with variable appearance, ascites Hypoechoic: breast, lung, lymphoma Hyperechoic: most likely colorectal cancer (most common primary) Target: Lung or colon Hepatoblastoma Pediatrics version of HCC. Elevated AFP, same clinical, similar sono appearance. Increased risk in Beckwith-Wiedemann syndrome (growth disorder) Not for Distribution 12 of 78  Abdomen Registry Review Study Guide Liver Transplants Hepatitis C most common reason requiring liver transplant. How? End-to-end donor to recipient portal vein and hepatic artery. Piggy back donor to recipient IVC Normal: liver dopplers should be same as normal native liver Portal vein: hepatopetal and minimally phasic Hepatic artery: hepatopetal and low resistance Hepatic veins: hepatofugal and pulsatile Rejection: abnormal doppler patterns. Elevated resistance hepatic artery, thrombosed or hepatofugal flow PV Post-operative: Transient increase RI hepatic artery. ** Most common vascular complication: hepatic artery thrombosis Infarction: hypoechoic wedge shapes regions throughout organ. May be caused by embolism or thrombosed artery Ultrasound guided liver biopsy Why? 1: non-targeted for staging of liver disease 2: targeted biopsy for mass Risk of complications: mainly bleeding related. Must have normal labs: PT, PTT, INR, platelets and no abnormal clotting disorders. Core biopsy gauge range 14-20 Ultrasound responsibilities Pre: assess liver for patient positioning and needle entrance point During: B-mode identify needle tip through area to be biopsied Post: assess for areas of hemorrhage Scanning technique Perpendicular incidence or 90 degree is best for visualizing needle Not for Distribution 13 of 78  Abdomen Registry Review Study Guide Gallbladder and Biliary Facts: Intraperitoneal GB stores and concentrates bile Ducts transport it Cholecystokinin (from duodenum) makes the GB contract releasing the bile into system Anatomy Flow of bile in the biliary tree Proximal to distal. Proximal is where it’s coming from. Distal is where it’s going. Intrahepatic biliary radicles (part of portal triads) drain into right and left hepatic ducts. RHD and LHD into CHD. CHD connects to cystic duct as it becomes extrahepatic. Cystic duct contains spiral valves of Heister which allow bile to flow into GB but not leak out until GB is contracted (with cholecystokinin). From cystic duct, then connects to CBD. CBD joins the main pancreatic duct at the ampulla of Vater. Sphincter of Oddi controls the flow of enzymes into the duodenum. Liver ➠ Biliary radicles ➠ R/L HD ➠ CHD ➠ cystic ➠ GB ➠ cystic ➠ CBD ➠ Ampulla Gallbladder Neck, body, and fundus: Fundus is the most dependent. Cystic duct connects neck of GB to rest of biliary tree. Vascular supply: Cystic artery (branch of right hepatic artery) Wall layers inner to outer: Mucosa > Fibromuscular > Serosa Not for Distribution 14 of 78  Abdomen Registry Review Study Guide Variants Phrygian cap: Most common. Fold of fundus over body Hartmann pouch: Outpouching of neck Junctional fold: Fold at neck Sonography NPO min 6 hours, otherwise GB wall will be contracted and appear thickened Normal GB wall thickness up to 3mm (Sagittal with calipers perpendicular to wall) GB width in transverse plane up to 4cm CBD up to 6mm at porta hepatis (Up to 10mm if hx cholecystectomy). In older patients, add 1 mm per decade of life (80yo = up to 8mm) Cystic duct may also be seen posterior to the CBD. Intro to Pathology Symptomatic pathology. Since this “organ” is really just a series of tubes, clinical findings will only be present if the disease is…. Irritating / Blocking / Infection Irritating = stones Clinical: pain, nothing else unless progressed to obstruction or infection Blocking = obstructive disease“blocking flow”. When dilated ducts or GB observed, evaluate distal to locate obstruction. Stones or tumors Clinical: Abnormal labs / jaundice / pain LABS: ALP and conjugated bilirubin Infection = acute -itis. Most commonly caused by obstruction. Clinical will be obstruction + infection symptoms Clinical: pain, labs, and infection symptoms like fever Not for Distribution 15 of 78  Abdomen Registry Review Study Guide Asymptomatic pathology. NOT irritating, blocking, infecting. These generally are GB wall abnormalities and have no abnormal clinical. AKA incidental or unrelated to symptoms Polyps Projection of tissue from GB wall. Cholesterol polyps are most common and usually 4cm indicates obstruction of distal biliary tree = cystic duct, CBD. Although intrahepatic ducts may be dilated, they would be a side effect and not the cause. The cause of biliary dilatation will always be see DISTAL to the dilatation. Further evaluation of CBD and pancreatic head is important to identify cause. Courvoisier GB: Enlarged GB caused by pancreatic head mass. Painless jaundice Infection Key symptoms: Fever, leuko, pain. Patients are SICK. Acute Cholecystitis Most common cause: obstructive gallstone in cystic duct or neck. Clinical: + Murphy’s sign (pain with probe pressure), fever, leuko, elevated ALP, bilirubin, nausea, vomiting Sono: Thickened GB wall, pericholecystic fluid, stones, sludge Acute Complications of the above “base” infection Gangrenous cholecystitis/Perforation Wall starts eroding. Bulging of wall, craters, and sloughed membranes. High risk for perforation. ** Dangerous = perforation may lead to peritonitis = death Empyema: Suppurative cholecystitis Pus filling and distending GB. Emphysematous cholecystitis Emphysema = air. Air or gas bubbles produced by bacteria in the wall. Increased risk: Diabetics and immunocompromised Sono: Reverberation (comet-tail or ring down) “champagne sign” Not for Distribution 18 of 78  Abdomen Registry Review Study Guide Acalculus Cholecystitis “No stone”. Most likely seen in children, hospitalized or immunocompromised pt. Clinical: RUQ pain, fever, leuko. Similar to acute cholecystitis with exception of NO obstructive labs. Sono: Thickened wall, pericholecystic fluid. No sludge or stone Acute cholangitis Similar to acute cholecystitis, but of the bile ducts. Most commonly caused by obstructed stone. Clinical: Charcot triad (pain, fever, jaundice), elevated ALP, bilirubin, nausea, vomiting Sono: Thickened bile duct walls >5mm, stones, sludge Chronic Complications Sclerosing cholangitis Sclerosis = hardening and thickening. Chronic type of fibrotic thickening of bile ducts. Increases risk for cholangiocarcinoma Miscellaneous conditions Pneumobilia “Pneuma” = air. Air or gas formation within biliary tree. Caused by recent surgery or infection. Sono: Comet-tail or ring down (reverb) artifacts scattered through liver Ascariasis Parasites in bile ducts. Movement of worm in realtime confirms presence of ascaris Not for Distribution 19 of 78  Abdomen Registry Review Study Guide Cancer Gallbladder carcinoma Most common cancer of the biliary tract. Suspected when polyp >1cm. Clinical: Weight loss, RUQ pain, jaundice if obstructive Sono: Non-mobile mass along wall >1cm Cholangiocarcinoma Cancer within the bile ducts. Most common type is Klatskin tumor, located at the junction of the right and left hepatic ducts (hepatic duct bifurcation). Ductal dilatation above the cancer. Clinical: Weight loss, RUQ pain, jaundice, pruritus (excessive itchiness), Hx of sclerosing cholangitis Sono: Dilated intrahepatic ducts that abruptly terminate Pancreatic carcinoma Although not a biliary disease, most common location of the mass is in the pancreatic head, therefore causing biliary obstruction. Clinical and sono will be similar to biliary obstruction: jaundice (direct bilirubin), elevated ALP and dilated ducts: CBD and proximal. Obstructive vs Non-obstructive Jaundice Both cause yellowing of skin/eyes and elevated direct (conjugated) bilirubin Obstructive = Blockage. Caused by biliary obstruction such as stones or cancer (cholangiocarcinoma or pancreatic). Often accompanies pain and elevated ALP Non-obstructive = No blockage. Caused by liver dysfunction that causes elevated bilirubin such as cirrhosis or hepatitis. Often has all LFTs elevated (ALP, ALT, AST) and pain is not a typical symptom unless it is acute Not for Distribution 20 of 78  Abdomen Registry Review Study Guide Congenital “Born with it” May be seen in peds or adults if it’s viable with life. Example: variants of GB (Phrygian cap or junctional folds) are congenital but they do not interfere with liver or GB function, so will always be seen in the patient at any age. Some congenital things are only seen in pediatrics because it is not compatible with life. Biliary atresia Narrowing or absence of biliary tree. Only seen in newborns/infants. Not compatible with life, will eventually cause liver failure and death if not corrected. Clinical: Neonatal jaundice/liver failure Sono: Absent ducts, fibrous cord appearance at porta hepatis Choledochal cyst Most common type is cystic dilatation of CBD. May be seen in infants or children. Again not adults, must be corrected Clinical: Biliary obstruction signs Sono: Cystic dilatation of CBD Caroli disease Segmental dilatation of the intrahepatic ducts Clinical: May eventually have biliary obstruction signs Sono: Central dot sign, segmental dilatation located in one part of the liver, color doppler may be helpful Not for Distribution 21 of 78  Abdomen Registry Review Study Guide Pancreas Facts: Retroperitoneal: anterior pararenal space Exocrine = Exit thru ducts Exocrine gland: enzymes produced by acinar cells Endocrine = Into the blood Amylase, lipase, sodium bicarbonate, trypsin Endocrine function: hormones produced by isles of Langerhans (alpha/beta/delta cells) Insulin, glucogon, somatostatin Anatomy Ducts (exocrine drainage) Main pancreatic duct AKA duct of Wirsung: travels length of pancreas and terminates when it meets with the CBD at the ampulla of Vater. Empties via sphincter of Oddi (major) Accessory duct AKA duct of Santorini: branch of main empties via minor sphincter into duodenum Vascular supply Gastroduodenal artery (branch of common hepatic artery) supplies head. Splenic artery and SMA supply body and tail Sonography Adult pancreas normally echogenic to liver, isoechoic to spleen. Pediatric pancreas normally can be hypoechoic to liver Main panc duct ≤2mm. May be seen perpendicular to sound beam at level of body. Color can be used to confirm its not the splenic artery GDA anterolateral aspect of head CBD posterolateral aspect of head Not for Distribution 22 of 78  Abdomen Registry Review Study Guide Anatomical Relationships IVC Posterior to head Duodedum Lateral to head Portal con uence Med to head/Ant to uncinate/Post to neck **or SMV Splenic vein Posterior to body/tail Splenic artery Superior to body/tail SMA Ant to aorta/ Post to panc body and splenic v Left renal vein Posterior to SMA Anterior to aorta Posterior to uncinate process Right renal artery Posterior to IVC Variants Divisum: Most common. Shortened main pancreatic duct, forces accessory duct to become primary drainage = inc risk dilated duct and pancreatitis Annular: panc head wraps around duodenum like a ring, may lead to bowel obstruction Not for Distribution 23 of 78 fl  Abdomen Registry Review Study Guide Pathology Acute Pancreatitis Most common cause: choledocholithiasis (gallstone). Other causes are alcoholism, trauma. Leakage of enzymes into pancreatic tissue causes inflammation. Amylase rises first Lipase within 72 hours but more specific for pancreatitis Clinical: Acute -itis symptoms = Fever, pain, leuko. Elevated amylase and lipase, biliary obstruction labs if caused by stone Sono: Initial = Normal. If findings = hypoechoic, enlarged, phlegmon (peripancreatic fluid), pseudocyst (most commonly in lesser sac), possible ductal dilatation ‣ Most common vascular complications: splenic vein thrombosis, splenic artery pseudoaneurysm Phlegmon vs Pseudocyst Phlegmon: Peripancreatic uid = uid surrounding edematous pancreas, not encapsulated and only with acute Pseudocyst: Encapsulated uid collection most commonly found in lesser sac. Can be with acute and chronic Chronic Pancreatitis Repeated bouts = damaged organ. Not the active infection! Most common found in cases of pancreatitis caused by alcohol abuse Clinical: Pain, jaundice$, abnormal labs, weight loss Sono: Heterogenous, hyperechoic with calcs, possible pseudocyst, possible ductal dilatation Not for Distribution 24 of 78 fl fl fl  Abdomen Registry Review Study Guide Pancreatic Adenocarcinoma AKA ductal adenocarcinoma. Most common primary pancreatic cancer. Most common location is the head = related to biliary dilatation. Courvoisier GB: enlarged, palpable GB caused by pancreatic head mass Clinical: Weight loss, abnormal labs = ALP, conjugated bilirubin Sono: Hypoechoic mass. Dilated ducts, possible enlarged GB Whipple procedure Removal of panc head, duodenum, GB, and bile duct Pancreatic Cystadenomas and Cystadenocarcinoma Serous (microcystic) are benign. Mucinous (macrocystic) may be malignant. Most commonly in body and tail. Since not in head, not usually related to biliary obstruction Clinical: Weight loss, pain Sono: Cystic or multilocular cystic mass Islet Cell Tumors Endocrine tumors. Usually benign but since hormone related will be symptomatic Insulinoma: More common. Symptoms of hypoglycemia Gastrinoma: May produce Zollinger-Ellison syndrome = too much stomach acid leading to peptic/ stomach ulcers. Pancreatic cysts Benign. Associated with other conditions: von Hippel-Lindau or renal cystic diseases Pancreatic Transplants For severe Type 1 DM (endocrine function). Exocrine function must have drainage… Exocrine enteric drainage: Most common. Donor duodenum to recipient jejunum RUQ Exocrine bladder drainage: Donor duodenum to urinary bladder ✓ For signs of rejection: inc RI in artery (see liver transplant) Not for Distribution 25 of 78  Abdomen Registry Review Study Guide Spleen Facts: Intraperitoneal Hematologic: Reticuloendothelial, Lymphatic = Filtering, Cleaning, Producing Blood ‣ White pulp: lymphatic function >> produces lymphocytes ‣ Red pulp: phagocytic function >> destroys the bad Culling = removes irregular cells “cutting out” Pitting = cleans RBC’s of unwanted material “polishing” Anatomy Vasculature Splenic artery: arises from celiac trunk, travels superior to body/tail of pancreas Splenic vein: travels posterior to body/tail of pancreas and drains into portal vein Ligaments Wandering spleen Gastrosplenic: stomach to spleen Abnormality of ligaments. Splenorenal: spleen to left kidney May lead to torsion Variants Accessory spleen AKA splenunculus, splenule, supernumerary spleen. Most common variant Most likely in hilum (superior to UP of LK or next to panc tail) Polysplenia: Multiple spleens/right sided spleen, related with left isomerism (heterotaxia) Asplenia: No spleen, related with right isomerism / double-rightsidedness (heterotaxia) Splenosis: “acquired”. Ectopic transplanted splenic tissue caused by splenic rupture Not for Distribution 26 of 78  Abdomen Registry Review Study Guide Pathology “Sensitive” organ Acute infection or hemolytic disorders initially cause splenomegaly. Chronic infections or repetitive hemolytic crisis will eventually damage spleen, atrophy/calc. Can be easily injured in cases of trauma = hemorrhage/rupture Splenomegaly Most common abnormality of spleen. Most common cause portal hypertension (with evidence of splenic varices). Other acute infections (HIV, hepatitis, Epstein-Barr), blood cancers, pediatric sickle cell anemia Clinical: Depends on cause Sono: >13cm in length and >6cm in thickness, losing concave shape. Extends beyond inferior pole of LK Infarction Tissue death because of deprived of oxygen. May be caused by infection, cancer, or torsion Clinical: LUQ pain Sono: Hypoechoic, wedge shaped Granulomatous disease Diffuse small hyperechoic foci. Damage to spleen from other infections. Pt with HX of histoplasmosis, tuberculosis, sarcoidosis. Not for Distribution 27 of 78  Abdomen Registry Review Study Guide Splenic Trauma Hemorrhage, hematoma, rupture, laceration Subcapsular hemorrhage: around the spleen, under capsule. Like “free fluid” with debris. Spleen will be intact Intraparenchymal: within the organ. Altered splenic texture, may be more focal inside of spleen. Clinical: Hx of trauma, decreased hematocrit, pain Sono: Anechoic to echogenic. Chronic (old) hematomas may should calcifications Focal benign Cyst Same as in any organ. Hemangioma Most common benign tumor, similar to liver hemangioma Abscess Same as any organ. Any abscess is an acute infection that is focal Cancer Most common primary is angiosarcoma. But lymphoma is the most common cancer of the spleen. Hodgkin Lymphoma: Reed-Sternberg cells, curable (better) Non-Hodgkin Lymphoma: More common, but less treatable (worse, but more common) Clinical: LUQ pain, fever, weight loss Sono: May be diffuse, splenomegaly or focal masses Pediatrics Splenomegaly: most likely caused by Epstein-Barr virus. Peds with sickle cell anemia will also show splenomegaly during a crisis. With time (adult), will be fibrotic and damaged. Not for Distribution 28 of 78  Abdomen Registry Review Study Guide Renal Facts: Retroperitoneal organ for homeostasis: detoxify and filter, balance pH, blood pressure Fibrous covering: Gerota fascia (surrounds kidney and adrenal gland) 2 main components to filter and then produce urine Parenchyma = Cortex and Medulla (Pyramids). Nephron is the functional unit. Cortex filters and pyramids absorb whatever the body wants to keep. What it doesn’t = urine Sinus = Collecting system to remove urine Filtering the blood Collecting system Arteries bring blood to the parenchyma Calices and pelvis drain urine Renal Artery Minor calyx ⇓ ⇓ Segmental Major calyx ⇓ ⇓ Interlobar Renal pelvis ⇓ ⇓ Arcuate Ureteropelvic junction ⇓ ⇓ Interlobular Ureter ⇓ ⇓ Nephron Ureterovesicular junction ⇓ ⇓ Pyramid Bladder Not for Distribution 29 of 78  Abdomen Registry Review Study Guide Anatomy Cortex forms outer rim = Hypoechoic compared to liver. Normal thickness >10mm Medulla is made up of pyramids = Hypoechoic compared to cortex. Columns of Bertin (cortical tissue) divide the pyramids Sinus = Hyperechoic due to fat content. Calices and pelvis is not seen if there’s no fluid distending it Variants ‣ Duplicated (duplex) collecting system: Most common variant. 2 renal sinuses divided by septum of cortex. Referred to as upper and lower moiety. Kidney may be longer and look like an 8. May cause hydronephrosis (usually lower moiety) due to ectopic ureter at UVJ ‣ Dromedary hump: Bulge on lateral border of left kidney ‣ Hypertrophic column of Bertin: Double layer of cortical column indenting into sinus ‣ Junctional parenchymal defect: Hyperechoic wedge shape along outer cortex ‣ Ectopic kidney: Failure to rise to renal fossa. Most likely in pelvis ‣ Horseshoe kidneys: Fusion of lower poles. Isthmus will cross anterior to aorta. Note image on right >> ‣ Extrarenal pelvis: Renal pelvis outside the hilum. May mimic hydro ‣ Sinus lipomatosis: Increased fat in sinus, look bigger than normal ‣ Compensatory hypertrophy: “makes up” for what’s not there. Unilateral conditions or anytime there is only one normal functioning kidney, the normal kidney becomes enlarged Not for Distribution 30 of 78  Abdomen Registry Review Study Guide Intro to Pathology Since the kidneys are made up into 2 parts = parenchyma and collecting system, we can divide the pathology into those 2 categories. Parenchymal Collecting System Functional part Series of tubes Compromised renal function Irritation Tumors/Cysts Obstructions and back-ups Infections Infections Lab values and clinical history Compromised Renal Function Blood Urea Nitrogen (BUN) and creatinine. These are the renal “function” tests. Will be abnormal in diffuse, bilateral conditions that affect the parenchyma/nephron/cortex. Azotemia Elevated BUN/Creatinine and other symptoms of poor renal function such as hypertension and dec GFR BUN and Creatinine (glomerular filtration rate). Diffuse and Bilateral Urinalysis Current condition. Not overall function. The prefix tells us what is elevated in the urine Pyuria = pus INFECTION Bacteriuria = bacteria INFECTION Hematuria = blood DAMAGE (stones/tumors) Proteinuria = protein MASSES/INFECTION Collecting system pathology Similar to biliary disease (see page 15). Irritating, Blocking, Infections Irritating: stones = pain and hematuria Obstruction: stones/tumors = pain, hematuria and sono: dilated structures Infection = acute -itis. Symptoms are typical infection signs + py/bacteriuria Not for Distribution 31 of 78  Abdomen Registry Review Study Guide Acute Renal Failure AKA acute kidney injury. Most common cause acute tubular necrosis. Sudden decrease in renal function, clinical more intense. Since initially appears normal, may be only a clinical diagnosis. Clinical: Elevated BUN/creatinine, hypertension, oliguria, hypovolemia, edema Sono: Initial normal (may only be clinical Dx), increased echogenicity of cortex Chronic Renal Failure Most common cause diabetes mellitus. Gradual decline in renal function due to damage of parenchyma. Clinical: DM, elevated BUN/creatinine, hypertension, hyperkalemia (high potassium) Sono: Small, echogenic kids, cortical thinning (6cm: high risk of rupture, critical report needed Iliac arteries Normal: 1.0 - 1.2cm Measuring the Aorta It’s important when measuring aorta and especially when aneurysm is present that the true lumen is measured in A/P outer to outer wall and perpendicular to the axis of the aorta, as properly indicated by the yellow dotted line in the image to the right. Aortic Dissection Separation or tear of intima from the medial layer Marfan syndrome: weakening of walls, increased risk of aneurysms and dissections Clinical: Severe abdominal, chest, and back pain Sono: Intimal flap or lining floating inside the aorta Pseudoaneurysm Puncture through all 3 layers creating a pulsating hematoma connected by a neck or channel to the native artery. Most likely following procedure (angio or cardiac cath) or trauma Sono: Pocket of swirling blood with communicating channel or neck to artery. Bidirectional flow/ to and fro pattern Not for Distribution 51 of 78  Abdomen Registry Review Study Guide Arteriovenous Malformation/Fistula Connection between artery and vein most often following trauma or interventional procedures. Flow patterns will be low resistance in the artery, high velocity/turbulent through the connection with arterial-like and pulsatile waveform of the outflow vein. Urgent notifications Life-threatening conditions or pathologies needing immediate intervention must be reported to physician as critical nding. Examples: AAA >6cm, signs of rupture, dissection, PSA, AVF Mesenteric Ischemia Arterial obstruction in celiac trunk and SMA. Signs of arterial stenosis includes elevated velocities and spectral broadening. Abnormal high resistance in the presence of a distal obstruction. IMA may be dilated as a collateral Clinical: Post-prandial pain, weight loss Sono: Abnormal flow patterns, elevated velocities in CA or SMA. Abnormal waveform resistance in post-prandial SMA. Prominently seen IMA Venous Anatomy IVC is formed by the union of the common iliac veins Renal veins drain into IVC. Left renal vein crosses anterior to aorta and posterior to SMA Hepatic veins last contribution to IVC (most superior) IVC terminates when draining into right atrium Normal IVC measures up to 2.5cm and varies in size with respiration Venous flow becomes more pulsatile as it gets closer to heart Portal venous system is unrelated to IVC system (pg 5) Not for Distribution 52 of 78 fi  Abdomen Registry Review Study Guide Venous Pathology Hepatic vein and IVC enlargement “Playboy bunny” sign. IVC > 2.5cm and lacks respiratory variation. Caused by right-sided heart failure or any another way to describe a congested right atrium. Veins will enlarge if they cannot flow into where they are supposed to go. IVC tumor thrombus Related to renal cell carcinoma (hypernephroma) and Wilms tumor (nephroblastoma). Cancer invasion via the renal veins *** if tumor in IVC, check kidneys for tumor! IVC filter Vena caval filter or Greenfield filter is placed in the infrarenal (below the renal veins) IVC. Purpose is to reduce risk of pulmonary embolism in high risk patients. Common Problems to Identify WHAT WHERE Nutcracker syndrome Left renal vein Tardus Parvus RA stenosis Segmental artery Post-prandial pain SMA or Celiac Solid renal mass IVC by the renal artery Filter IVC or Infrarenal IVC Caliper for AAA Outer border/perpendicular Not for Distribution 53 of 78  Abdomen Registry Review Study Guide Gastrointestinal Facts: Mucosa, muscularis, serosa divided into 5 histologic layers, alternating echogenicity. Muscle layer will be outer hypoechoic layer Normal bowel is compressible Scanning technique Non-compressible may have target sign Graded compression sonography useful in appearance determining normal from abnormal bowel “Gut signature” Inner to Outer Superficial mucosa Echogenic Deep mucosa Hypoechoic Submucosa Echogenic Muscularis Hypoechoic Serosa Echogenic Pathology GI studies are typically targeted for specific bowel abnormalities based on clinical findings Acute appendicitis Inflammation of the vermiform appendix, blind ended tube extending from cecum. Most common cause of acute abdominal pain resulting in surgery. McBurney point: RLQ between ant superior iliac spine and umbilicus Clinical: Rebound pain at McBurney point, fever, nausea/vomiting, leukocytosis Sono: Non-compressible blind ended tube, >6mm in diameter, hyperemia, may also have appendicolith Not for Distribution 54 of 78  Abdomen Registry Review Study Guide Hypertrophic pyloric stenosis Gastric outlet obstruction: enlargement or thickening of the pyloric sphincter. The pylorus is the channel that empties into the duodenum. Most commonly seen in male newborns 10mm. May be caused by iodine deficiency, Graves or Hashimoto’s Clinical: Palpable swelling, feeling of tightness, hoarse voice Sono: Diffusely heterogeneous with isthmus >10mm Graves disease AKA diffuse toxic goiter. Most common cause of hyperthyroidism. Thyroid inferno: refers to hypervascularity that is characteristic Clinical: Bulging eyes, weight loss, nervousness, intolerant to heat Sono: Thyroid enlargement (goiter), heterogeneous, thyroid inferno Hashimoto’s thyroiditis AKA chronic autoimmune lymphocytic thyroiditis. Most common cause of hypothyroidism. Initially the thyroid becomes inflamed due to autoimmune response. Over time, thyroid becomes damaged and hormone levels will drop. Sonographic appearance varies with stage of disease. Pituitary gland will send more TSH to try and stimulate the thyroid. So low T3/T4 hormones but high TSH Clinical: Weight gain, cold intolerant, puffy face Sono: Initially enlarged, chronic heterogeneous and hypoechoic with fibroid bands De Quervain's thyroiditis Subacute transient inflammation most often caused by viral infection. Clinical: Pain and swelling. Phases of hyperfunction, then hypofunction then back to normal. Sono: ill-defined areas of decreased echogenicity and decreased vascularity Not for Distribution 61 of 78  Abdomen Registry Review Study Guide Benign nodules: very common in thyroid and usually multiple Clinical: Asymptomatic or due to size, palpable/difficulty swallowing Sono: Variety of appearances, cystic, hypoechoic, isoechoic, complex, halo Nodular Hyperplasia (adenomatous nodules) are the most common cause of thyroid nodules AKA multinodular goiter Colloid cyst: Cyst with hyperechoic focus in center Follicular adenoma: Solitary, encapsulated nodule Malignant nodules Papillary carcinoma: Most common thyroid cancer. Suspicious for cancer if solitary, hypoechoic with microcalcifications. Eval for cervical lymphadenopathy for invasion: solid, rounder shape Benign vs Malignant Usually multiple Often solitary Cystic Taller than wide Echogenic Hypoechoic/heterogeneous Halo Microcalcifications Hot nodule on Nuc med Cold on Nuc med Cervical lymphadenopathy Nuclear medicine scan Radioactive Iodine Uptake measures thyroid function. Hyperfunction (Graves or hot nodule) Hypofunction (Thyroiditis or cold nodule) Not for Distribution 62 of 78  Abdomen Registry Review Study Guide Parathyroid glands Paired endocrine glands (4 total) posterior to each lobe of the thyroid Not well seen if normal since only 5mm and are isoechoic to thyroid tissue Calcium regulators (by the release of PTH parathyroid hormone) Parathyroid adenoma Most common cause of enlargement of parathyroid. Clinical: Hyperparathyroidism, hypercalcemia Sono: Hypoechoic mass posterior to MP thyroid Hypercalcemia and Related Pathology Increased calcium in the blood Deposits in kidneys: causes nephrocalcinosis Other Neck Pathology Cervical lymphadenopathy Abnormal: >1cm, round, loss of normal echogenic hilum becoming more solid and hypoechoic, hyperemic (increased blood flow) Reactive: may have normal appearance and shape, just may be enlarged. Thyroglossal duct cysts Midline superior to thyroid, just under the chin (most common neck cyst) Branchial cleft cysts Superior to thyroid but near the mandible Not for Distribution 63 of 78  Abdomen Registry Review Study Guide Musculoskeletal and Super cial Facts: Muscles appear hypoechoic with echogenic striations Tendons are fibrous and more echogenic compared to muscle Bleeds, ruptures, and fluid collections will have same appearance as any other location Tendon Rupture Aka tear. Partial seen as focal hypoechoic area and complete as fluid filling the gap of the tear Achilles tendon tear: most commonly injured ankle tendon Thompson test performed to rule out complete tendon tear. Calf is squeezed while patient is prone. Normal result is plantar flexion. Developmental Dysplasia of Infant Hip When femoral head does not properly sit inside the the acetabulum due to the socket being shallow. Femoral head may also be dislocated (completely outside the acetabulum) or subluxated (partially dislocated). Clinical: Inc risk with breech fetal lie and oligohydramnios, audible click, leg length discrepancy, positive Barlow or Ortolani test Ortolani Barlow O for “out” = Abduction Adduction Reduction or relocation of hip Dislocation of hip Technique: Coronal image and Graf technique (green lines) is obtained by measuring angles of femoral head (FH) coverage in relation to ilium. Alpha angle (bottom): Normal >55% Beta angle (top): Normal 2mm within the scrotum, pampiniform plexus “backed up”. Lateral to testicles (extratesticular). Most common cause of correctable male infertility, due to heating of sperm. Valsalva maneuver or standing will increase abdominal pressure caused venous blood to reflux back. Varicocele will flush rapidly with color Primary: Caused by incompetent valves and most likely on left since left testicular vein is longer Secondary: Caused by other pathology in abdomen/pelvis and usually when on right. Warrants investigation of renal or retroperitoneum Scrotal pearl Mobile calcification within the tunica vaginalis. Remnant torsed appendage Not for Distribution 71 of 78  Abdomen Registry Review Study Guide Inguinal-scrotal hernia Indirect inguinal hernia may descend into the scrotum. Valsalva will push the hernia further into the scrotal sac and peristalsis may be evident. May be fat or bowel superior to testes Intratesticular cysts Tubular ectasia of rete testes Visible, dilated rete testes along mediastinum (intratesticular). Usually seen as a cluster along side of testes. May be seen in patients that have had a vasectomy. Incidentally noted, asymptomatic Epidermoid cyst: onion layer or “whorled” appearance Microcalcification / Microlithiasis Diffuse microcalcifications. Asymptomatic, increase risk testicular cancer Cancer Solid masses of testicle are most likely malignant germ cell tumors. Most likely there will be an elevation in labs: hCG and/or AFP Seminoma Most common testicular malignancy Risk factors: Hx cryptorchidism, microcalcifications Clinical: Palpable mass, elevated hCG Sono: Solid, hypoechoic or heterogeneous intratesticular mass Other germ cell tumors and labs (be familiar with names) Yolk sac tumor: elevated AFP only Choriocarcinoma: elevated hCG only Embryonal cell carcinoma: elevated hCG and AFP Not for Distribution 72 of 78  Abdomen Registry Review Study Guide Penis Dense fibrous covering: Buck fascia Paired corpus cavernosa (dorsal) covered by tunica albuginea (yellow arrows) Singular corpus spongiosum (ventral) that contains the urethra (red arrow) Arterial blood supplied by internal pudendal artery Dorsal view Peyronie disease Fibrous plaque (hard tissue) and scarring of tunica albuginea causing painful curvature of the penis Penile trauma Fracture caused by blunt force trauma. Corpus cavernosum may be hemorrhaged, important to evaluate the tunica albuginea for irregularity Vasculogenic Impotence Arterial insufficiency caused by proximal arterial stenosis or venous incompetence caused by venous leak Not for Distribution 73 of 78  Abdomen Registry Review Study Guide Prostate Retroperitoneal and exocrine glands to make up semen Prostate-specific antigen (PSA) is a protein produced by prostate. When elevated indicates abnormality but not specific for cancer Sperm Pathway ‣ Deferent duct (vas deferens) ascends from scrotum and goes to seminal vesicles ‣ Seminal vesicle secrete fluid and now becomes ejaculatory duct ‣ Ejaculatory duct travels to prostate where it meets up with urethra at the verumontanum Prostatic zones Peripheral: largest, posterior and apical Central: 2nd largest, located at base (superior) Transitional: on both sides of urethra Anterior fibromuscular stroma: covering anterior Sonography Transabdominal Seminal vesicles: small hypoechoic posterior to bladder and superior to base of prostate Prostate: posterior inferior to bladder. Base closest to bladder, apex often shadowed by pubic bone on right side of image Normal volume up to 30mL (L x H x W x 0.52) Not for Distribution 74 of 78  Abdomen Registry Review Study Guide Transrectal: Look for footprint, may be at bottom or at top! Coronal plane: zone closest to transducer footprint is peripheral and also apical Sagittal plane: peripheral is still closest to transducer face. Apex would be inferior (to right) and base would be superior (to left) Benign Prostatic Hyperplasia Enlargement of the prostate most often in the transitional zone. Since this zone surrounds the urethra, it will compress it, symptoms include urinary difficulty Clinical: Elevated PSA, urinary frequency/urgency, incomplete emptying Sono: Volume >30mL, may indent into bladder with thickened irregular walls, prostatic calcifications common in older patients, large post-void residual PVR Prostate cancer Most common cancer in men. Most common location is peripheral zone. Clinical: Elevated PSA, hematuria, hematospermia (blood in semen), back/hip pain Sono: Hypoechoic lesion in peripheral zone Prostatitis: Inflammation/infection of the prostate Peripheral Transitional Central Largest and Apex Near urethra Base / Superior Closest to TR transducer face Makes prostate huge No speci c diseases Prostate cancer zone BPH zone Not for Distribution 75 of 78 fi  Abdomen Registry Review Study Guide Physics Review Artifacts associated with pathology Image optimization based on patient, study type, and findings Artifacts Reverberation / Comet tail / Ring down Several bright, false echoes deep to real reflector. Usually helpful if caused by pathology. May also falsify membrane or intimal flap within vessel Examples: microcalcifications (adenomyomatosis), gas bubbles (emphysematous pathology), foreign body, biopsy needle Posterior shadowing Severe attenuation seen as dark band deep to highly reflecting object Examples: stones, bony structures Posterior enhancement Lack of attenuation seen as brighter area posterior to fluid-filled structures Examples: cysts, abscesses, hematomas Mirror image Copy of echoes deep to real anatomy/specular reflector. May be seen in color. **not helpful. Change scanning angle Example: liver/diaphragm, aorta Side/Grating lobes False echoes placed laterally within anechoic structure **not helpful. Adjust gains, dynamic range or apply harmonics Example: False septation in gallbladder or cyst Good and Bad Artifacts Some artifacts are necessary and useful for diagnosis Example: posterior shadowing or twinkle sign helps confirms a stone Some artifacts are never helpful and should be avoided or corrected Example: Side or grating lobes seen within a cyst Not for Distribution 76 of 78  Abdomen Registry Review Study Guide Image Optimization B-mode scanning technique 90 degrees AKA perpendicular imaging angle is best for smooth interfaces such as visualizing a vessel wall or biopsy needle Transducer frequency choice Frequency and Transducer Study type and focus Super cial = High frequency linear 9-12 MHz Patient body habitus Deeper = Low frequency curved 2-6 MHz ‣ More superficial the imaging = choose the higher within the frequency range ‣ More penetration is needed = lower the frequency Doppler principles Determining flow direction First, look at the scale. The color on top is positive and bottom is negative. Red is positive in this image so it is towards the probe or top of the screen. In this image taken from the right flank, the red vessel is flowing from right to left, laterally. The blue vessel is flowing away from the probe which means to left to right, medially. How to correctly use Color Doppler The size of the box should just cover area of interest. Adjust the scale to fit the type of flow you are evaluating. Adjust color gain so color fills in vessel but does not ‘bleed’ out of the vessel walls. Not for Distribution 77 of 78 fi  Abdomen Registry Review Study Guide Doppler Optimization Velocity Scale aka PRF Needs to match the type of flow you are evaluating Decrease the scale = for slower flow Increase the scale = when it’s aliasing Wall filters and High Pass filters Filters LOW FREQUENCY/HIGH AMPLITUDE. Decrease WF = when not sensitive enough Gain Fine tuning only! First adjust scale and wall filter appropriately. Increase gain to enhance the strength of the doppler signal Decrease if bleeding out of vessel Power Doppler Use power doppler when you only are interested in presence of flow. Benefits: very sensitive to slow flow Limitation: no direction information High velocity ow Low velocity ow High scale Low scale / Low wall lter Renal arteries Internal parenchymal ow Aorta R/O testicular torsion Celiac / SMA Eval ow intussesception Not for Distribution 78 of 78 fl fl fl fi fl