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DMS Abdominal Ultrasound video notes (copy)

1. Introduction to Abdominal Sonography (0:17)
  • Instructor: Mikaela George Parton

    • Teaches general side: OBGYN, abdomen lecture and lab.

    • Clinical coordinator for the general side.

    • Specialties: abdomen, OBGYN, breast.

    • Credentials: RDMS sonographer.

    • Work Experience: Mostly radiology department (abdomen, small parts), currently PRN for an OBGYN group (babies, pelvis).

  • Topic: All things abdomen, including organs in the abdomen and part of the pelvic region.

  • Key Skill: Abdominal sonographers must be well-versed in relational anatomy (how organs fit, work together, and influence examination of other organs).

2. Lecture Objectives (1:37)
  • Define indications for abdominal exams.

  • Recognize normal abdominal anatomy and surrounding structures (relational anatomy).

  • Compare capabilities and limitations of ultrasounds.

  • Understand required instrumentation (probes, settings).

  • Identify indications for specific exam types.

  • Demonstrate basic scanability during lab (liver, right kidney, midline structures - left lobe/liver in relation to IVC/abdominal aorta).

  • Capture images.

3. Purpose of Abdominal Exams (2:57)
  • Mechanism: Use sound waves to produce images of organs and vasculature within the abdominal cavity.

  • Crossover Specialty: Significant overlap with vascular sonographers (abdominal aorta, liver Dopplers, renal Dopplers).

  • Examined Areas: Upper abdomen and part of the pelvis.

  • Diagnostic Uses: Help diagnose structural abnormalities or pathology of:

    • Liver

    • Gallbladder

    • Bile ducts (associated with liver)

    • Pancreas

    • Both kidneys and bladder

    • Spleen

    • All abdominal vasculature (from diaphragm to bifurcation into iliac arteries).

  • Examples of Images (4:00 onwards):

    • Transverse liver view showing hepatic veins from IVC.

    • Liver and gallbladder illustrating relational anatomy.

    • Pancreas (transverse view, midline, epigastric region):

      • Hyperechoic structure is ???, also aorta, renal vessels, SMA, splenic vein becoming portal splenic confluence/portal vein.

      • Emphasizes knowledge of landmarks for accurate imaging.

    • Right kidney and right lobe of liver (longitudinal plane) (5:30).

    • Spleen (left upper quadrant), noting similar echogenicity to liver parenchyma (5:59).

    • Color Doppler of abdominal aorta and superior mesenteric artery (SMA) (6:18) (similar to carotid lab).)

4. Credentialing and Interpreting Doctors (6:24)
  • Credentialing Agencies:

    • ARDMS (American Registry for Diagnostic Medical Sonography): Gold standard.

      • Credential: RDMS (Registered Diagnostic Medical Sonographer), with (AB) for abdomen specialty.

    • ARRT (American Registry of Radiologic Technologists): Secondary.

      • Credential: RT (Radiologic Technologist), with (S) for sonography.

      • Broader general test, less specialization in individual ultrasound specialties than ARDMS.

  • Interpreting Doctors:

    • Radiologists (vast majority):

      • Specialize in most medical imaging (X-ray, mammography, CT, MRI, nuclear medicine, PET scan).

      • Ultrasound and MRI are the main modalities without radiation.

      • Perform diagnostic procedures: biopsies, fluid drainage, catheter placement, OR assistance.

      • Utilize multiple screens to compare MRI, ultrasound, X-ray for best diagnosis (ultrasound is often a small part of the overall diagnostic evaluation).

      • Example: Ultrasound-guided breast biopsy (9:08).

5. Relational Anatomy of Abdominal Organs (9:30)
  • Importance: Critical for adequate and accurate imaging in the upper abdomen.

  • Organ Locations and Relationships:

    • Liver, Gallbladder, Bile Ducts: All associated with the liver.

    • Pancreas: Posterior and slightly inferior to the left lobe of the liver.

    • Kidneys and Bladder: Lateral, either side of the vertebrae.

      • Right Kidney: Posterior and slightly inferior to the right lobe of the liver.

      • Left Kidney: Slightly left lateral and slightly inferior to the lateral tip of the left lobe.

    • Spleen: Just lateral and slightly superior to the left kidney.

    • GI Tract: Not the best modality for bowel imaging, but improving with technology (higher frequencies, better penetration).

      • Bowel contains air/gases, which scatters sound waves, making images blurry.

      • Small intestines, ascending, transverse, and descending colon overlap organs.

      • Challenge: Imaging the inferior (lower) pole of the right kidney due to overlay by transverse and ascending colon (air artifact).

  • Imaging Planes for Comparison (12:28):

    • Axial/Transverse Images: Used by CT and MRI; sonographers need to recognize these for comparison.

    • Sagittal Cross-section: Shows liver (intraperitoneal) and kidney (retroperitoneal).

      • Scanning from anterior goes through liver and bowel (air)..

      • Lateral approach: Go through less liver, directly to kidney, reducing air artifact from bowel, making it easier to image.

  • Vasculature (13:43):

    • Aorta, IVC (inferior vena cava), renal vessels (arteries/veins), splenic vessels, mesenteric vessels (feed bowel, extract nutrients).

    • Diagram shows close relationship of all major vessels and organs: renal veins/arteries, SMA, celiac branch, hepatic veins, ureters.

    • General sonography images everything from diaphragm to pelvis.

6. Types of Abdominal Exams (14:38)
  • Principle: Do not typically scan only one organ; most are grouped into systems.

  • Complete Abdomen: Requested for generalized belly pain.

    • Scans everything in the upper abdomen: aorta, liver, gallbladder, pancreas, kidneys, spleen, often bladder.

  • Right Upper Quadrant (RUQ): Most common exam (for right upper quadrant pain, e.g., gallbladder stones).

    • Includes liver, gallbladder, bile ducts, pancreas, and only the right kidney.

    • Aorta and IVC are evaluated as they relate to the liver, but not a full aortic scan.

  • Renal Exam: Second most common.

    • Kidneys and bladder.

    • Sometimes includes abdominal aorta and IVC (retroperitoneal structures).

7. Gross Anatomy and Imaging Depth (16:08)
  • Visualizing Layers:

    • Skin line, musculature, omentum, vascular going into digestive tract.

    • Liver (right and left lobes), gallbladder.

    • Further in: intestines (small bowel, large intestine: ascending, transverse, descending colon).

    • Liver tissue is spongy; main portal vein splits into left and right (right often hidden behind gallbladder).

    • Gallbladder is green (bile).

    • Diaphragm visible (posterior portion).

    • Spleen is very posterior.

    • Splenic vein joining SMV to become portal vein.

    • Still anterior to main aorta and IVC (intraperitoneal).

    • Retroperitoneal Space (19:00):

      • Abdominal aorta, renal arteries, iliac bifurcation.

      • IVC: runs through the parenchyma of the liver.

      • Aorta: posterior to the liver and does not touch it (splits through diaphragm.

      • Typical scan depth: 11 to 16 cm (6 slices) from anterior to posterior wall.

8. Anatomy and Function of Specific Organs

8.1 Kidneys (20:20)

  • Location & Shape: Retroperitoneal, paired, bean-shaped organs.

  • Size: Average 10-13 cm long, 5-7.5 cm width.

    • Length is most diagnostic for size.

    • A single functioning kidney will enlarge to compensate.

  • Structures Examined:

    • Capsule (GERRARDOUS fascia): Tough protective layer.

    • Cortex: Outer portion.

    • Medulla: Inner portion, contains renal pyramids.

    • Renal pyramids: Where filtration occurs.

    • Renal sinus: Central echogenic area (fat content).

    • Renal pelvis/hilum: Collecting system.

    • Ureters: Course from kidney to bladder.

    • Renal artery and vein.

  • Main Function:

    • Filter toxins and excess water to form urine.

    • Reabsorb nutrients and salts to maintain blood balance.

    • Regulate blood pressure.

  • Refresher (A&P):

    • Blood with waste enters, filters through nephrons, goes to renal pelvis.

    • Pyramids are where primary work happens (collecting tubules).

    • Waste flows to bladder via ureter.

  • Sonographic Appearance (22:26):

    • Diagram (upright) rotated 90 degrees to match ultrasound (longitudinal sagittal plane).

    • Renal Pyramids: Hypoechoic areas.

    • Renal Sinus: Hyperechoic tissue (more fat content than parenchyma), where urine collects.

    • Renal Pelvis: Funnel-shaped, directs urine to ureter (not always visible).

    • Cortex: Outer portion.

    • Medulla: Contains pyramids.

    • Renal Capsule: Can be hyperechoic (sometimes an echogenic halo).

    • Column of Bertin: Prominent renal medullary tissue extending centrally (less focus in this class).

    • Ureter: Not visible normally unless obstruction (stone, mass) causing backup.

    • Echogenicity: Renal parenchyma slightly hypoechoic to normal right liver lobe.

    • Orientation: Superior pole, inferior pole, ureter extends towards feet.

8.2 Liver (26:39)

  • Largest Abdominal Organ: Fills most of the upper abdomen.

  • Extension: Far lateral left to right, sometimes down to top of pelvic bone on right.

  • Shape: Wedge-shaped; right lobe is majority.

  • Size Variation: Lots of variation; main measurement is liver length (diaphragm to most inferior point).

    • Average length: about 15 cm (variable with height, weight, gender).

  • Structures Imaged (General Overview):

    • Right and left lobes.

    • Caudate lobe (imaged separately from right lobe on ultrasound).

    • Hepatic and portal veins.

    • Complete imaging from far left to far right, superior to inferior, including all vasculature.

  • Functions (over 500):

    • Digestion & Metabolism: Produces bile (digests fats), metabolizes proteins/carbs.

    • Energy Storage: Stores excess carbs (glycogen), releases for energy.

    • Vitamin Storage: Stores Vitamins A, D, E, K.

    • Blood Filtration: Filters blood from GI tract before it goes to heart (removes bad, passes good).

    • Red Blood Cell Removal: Breaks down old RBCs, processes nutrients, excretes toxins.

  • Histologic Example (Anterior View) (29:49):

    • Right lobe, left lobe (can be very prominent).

    • Ligaments: Falciform ligament, coronary ligaments (hold liver in place).

    • Gallbladder: Attached posteriorly by a stem (cystic duct), like a water balloon that expands/contracts.

    • Posterior View: Ligamentum venosum, ligamentum teres (landmarks).

    • Caudate lobe is imaged separately; quadrate lobe is part of the right lobe.

  • Diagrams vs. Sonographic Image (31:37):

    • Diagrams (upright) must be conceptually rotated 90 degrees for ultrasound.

    • Sagittal section shows liver domed under diaphragm, kidney below.

    • Sound wave path: Anterior approach goes through liver, bowel (air), then kidney.

    • Lateral approach: Through less liver, directly to kidney, reducing air artifact.

  • Sonographic Appearance (33:59):

    • Anterior (skin line, subcutaneous fat), inferior right lobe, then kidney posteriorly.

    • Diaphragm: Very thin, strong, dense muscle; shows as bright echogenic line superior to liver.

    • Transverse view: Right/left lobes, portal vein, vertebrae, kidneys (left kidney often hard to see).

    • Longitudinal right lobe: Glisten's capsule (outer capsule around liver) is a bright echogenic line.

    • Vascular portion of liver exam: Color Doppler of hepatic/portal veins; pulse wave imaging of portal/hepatic veins and hepatic artery (small).

8.3 Gallbladder (36:47)

  • Location: Attached to the posterior right liver lobe by bile ducts.

  • Function: Liver produces bile, pumped into gallbladder via cystic duct, stored until food eaten.

  • Mechanism: Contracts to squeeze bile into duodenum (first part of intestine) to digest fats.

  • Size: Up to 10 cm in length (normal); larger may indicate obstruction.

  • Process: Fills between meals (fasting); contracts when eating.

  • Sonographic Appearance: Can be confused with blood vessel if thin/elongated; use color Doppler to differentiate.

    • Sits on posterior mid-right lobe, close to IVC and portal vein.

8.4 Abdominal Vasculature (38:29)

  • Aorta (38:29):

    • Sagittal Midline View: Aorta and branches (celiac, SMA).

    • Relationship with Liver: Separation between anterior aorta and posterior left lobe of liver.

    • Function: Sends oxygenated blood from heart to abdomen/lower extremities.

    • Imaging: Long and transverse planes (superior, mid, inferior/distal portions).

    • Branches imaged: Celiac, SMA, renal vessels, bifurcation towards pelvis.

    • Measurement: AP (anterior-posterior) and transverse width (for aneurysms).

    • Color Doppler: Shows celiac and SMA branching; no vessels coming directly from liver into aorta.

  • IVC (Inferior Vena Cava) (41:13):

    • Relationship with Liver: Vessel goes through the liver, touching its posterior portion.

    • Function: Returns deoxygenated blood from abdomen/lower extremities to right atrium of heart.

    • Imaging: Connects directly to heart, visible point of connection.

    • Imaging Difficulty: Difficult to see IVC behind bowel; typically image only superior portion.

    • Compressibility: Being a vein, it collapses with pressure.

    • Optimization: Patient sniffing or deep breath dilates IVC, making it more prominent.

    • Main Reason for Scan: Evaluate for thrombus, masses extending into IVC.

    • Color Doppler: Shows hepatic veins entering IVC and going into right atrium.

8.5 Spleen and Pancreas (42:33)

  • Spleen:

    • Location: Left upper quadrant, posterior to stomach, inferior to diaphragm.

    • Relationship: Sits like a cap at the end of the pancreatic tail.

    • Function (Adult): More of a storage container for blood; not essential for adult life.

    • Friable: Prone to rupture from blunt force trauma, leading to surgical emergency (splenectomy).

    • Other Functions: Blood filtration, immunity (more important in children).

    • Normal Length: Up to 13 cm; larger is cause for concern.

    • Ideal Window: Left side, lateral or coronal approach (longitudinal and transverse); often imaged in relation to kidney.

  • Pancreas:

    • Location: Closely related to spleen at tail, but central portion related to duodenum and gallbladder.

    • Regions: Epigastric region and left upper quadrant (tail).

    • Functions: Endocrine (hormone control, blood glucose) and exocrine (food digestion, secretes enzymes into bowel).

    • Relationship: Both organs work closely with bile duct to digest food.

    • Ideal Window: Midline transverse orientation (head, body, tail visible).

    • Ultrasound Image: Uncinate process, head, body, tail extending posteriorly.

      • Left lobe of liver anterior to it, surrounded by vasculature.

9. Review of Echogenicity (45:40)
  • Left liver lobe is medial to the right kidney.

  • Liver is hypoechoic to the diaphragm (diaphragm is very echogenic).

  • Kidney appears complex/heterogeneous (renal pyramids hypoechoic to renal cortex, both hypoechoic to renal sinus fat).

  • Renal sinus fat is hyperechoic to renal pyramids.

  • Normal kidney parenchyma is slightly hypoechoic to a normal right liver lobe (used for echogenicity comparison).

10. Scanning Orientation & Patient Positioning (46:50)
  • Orientation Labels: Consistent with other anatomy.

    • Sagittal/Coronal: Superior/Inferior.

    • Lateral approach: Top of image is right/left or right/medial.

  • Patient Positioning (Lots of variation):

    • Supine, Left Lateral Decubitus (LLD), Left Posterior Oblique (LPO), Right Lateral Decubitus (RLD), Right Posterior Oblique (RPO), Upright.

    • Sonographers typically scan from the right side of the patient (sitting or standing, find what works ergonomically).

  • Sonographer Ergonomics (48:20):

    • Machine near patient's head.

    • Adjust bed height.

    • Maintain less than 30-40 cm reach with either arm.

    • Keep scanning arm close to body (less than 30 degrees abduction).

    • Monitor at eye level.

    • Lean into patient, move machine/patient, adjust chair/bed.

    • Use pillows/cushions/bolsters/wedges to rest arm.

    • Protect body to avoid long-term injuries.

  • Probe Placement/Scan Windows (49:11):

    • Varies by organ and even within the same organ (e.g., liver requires multiple windows).

    • Windows: Midline epigastric, right/left lateral, intercostal, pelvic.

    • Planes: Transverse, sagittal, oblique, coronal (all over the belly).

    • Example Scan Path (50:20):

      • Midline (pancreas, abdominal vasculature, left liver lobe).

      • Lateral intercostal (upper right liver, part of kidney).

      • Lower right liver, right kidney.

      • Tail of pancreas, spleen, left kidney (superior portion).

      • Lower portion of left kidney.

      • Lower abdominal vasculature, bladder.

      • At least 6 different windows on one body.

    • Probe Angulation: Angle and push into belly, angle up towards chest to see entire superior portion of organs (e.g., liver).

    • Imaging organs in bits and pieces is necessary for adequate imaging.

  • Patient Respiration (52:33):

    • Deep breath and hold (inspiration): Pushes diaphragm out from behind ribs, pushes liver/kidney down, moves bowel out of the way.

    • Diaphragm pulls lungs down, liver pushed to subcostal orientation, bowel moved inwards/downwards.

11. Instrumentation (60:04)
  • Probes:

    • Curved Linear Probe: Most common for abdominal exams.

      • Frequency: Typically 2-6 MHz (mid-range, good for deeper structures).

      • Higher megahertz for thin patients.

    • Phased Array Probe: Smaller footprint.

      • Frequency: Typically 1-5 MHz (lower for larger/denser patients).

      • Good for intercostal scanning (gets between ribs) even in smaller patients.

  • Controls/Settings:

    • Overall Gain & TGC Profile: Adjust brightness; TGC compensates for sound attenuation in far field.

    • Depth: Adjust to optimize organ visualization, avoid cutting off posterior structures or wasting space.

    • Focus: Position at or just posterior to region of interest for sharpest resolution.

      • Focal range (on Philips machines): Highlight and adjust the size of the focal zone for specific areas.

    • Frequency/Fusion (Philips specific):

      • Options: Penetration, General, Resolution optimized.

      • Penetration: Lower frequencies (e.g., 2-4 MHz).

      • Resolution: Higher frequencies (e.g., 4-6 MHz).

      • General: Mid-range (e.g., 3-5 MHz); default preset.

      • Control wheel on 2D button for adjustment.

12. Exam Preparation & Indications

12.1 General Preparation (66:45)

  • Fasting: Nothing by mouth for 4-12 hours (longer is better).

    • Quiets bowel, allows gallbladder to expand.

  • Bladder (for renal exam): Fasting, then drink water and hold bladder for prevoid volume measurement; post-void residual measured after emptying.

  • Attire: Comfortable, loose-fitting clothes, easy to remove, not easily damaged by gel.

12.2 Liver Exam Indications (68:07)

  • Generalized abdominal pain (upper portion).

  • Abnormal blood work (liver functions, general check-ups).

  • Screening for hepatic disease.

  • Jaundice (physical exam or blood work).

  • Monitoring chronic liver disease (hepatitis, cirrhosis).

  • Portal hypertension (impeded blood flow to liver).

  • Guidance for interventional studies (biopsies, therapeutic interventions for cancer).

  • Conjunction with other imaging modalities (MRI, CT, X-ray); common follow-up from CT for liver masses (e.g., hepatocellular carcinoma).

  • Follow-up on Liver Function Tests (LFTs).

12.3 Kidney & Bladder Scan Indications (69:59)

  • Pain (abdominal or flank).

  • Abnormal blood work.

  • Hematuria (blood in urine, visualized or on urinalysis).

  • Recurrent UTIs.

  • Kidney stones (big indication, cause pain, urine backup).

    • Crystals form in collecting system, painful if stuck in ureter.

    • Sonographic appearance: bright echo with shadow (e.g., stone causing shadow in renal pelvis).

  • Follow-up from renal injury.

  • Follow-up on cysts or tumors/masses.

  • Evaluation of congenital anomalies (improper formation or location).

  • Following up on other imaging exams (CT is common).

13. Professional Organizations & Protocols (71:50)
  • AIUM (American Institute of Ultrasound in Medicine): Sets minimum required images for each exam type, collaborates with doctors and sonographers.

  • Protocols: Vary slightly by practice/location (different order, extra images).

  • Examples:

    • Complete Abdominal Scan: Liver, gallbladder, pancreas, spleen, kidneys, aorta, IVC (includes required images for each).

    • Limited Exam (e.g., RUQ): Liver, gallbladder, pancreas, right kidney, aorta/IVC (as they relate to liver, not full scan).

    • Renal Exam: Right/left kidneys, bladder (sometimes aorta/IVC due to retroperitoneal location).

14. Lab Focus & Imaging Examples (73:41)
  • Lab Scan Focus:

    • Coronal and anterior windows.

    • Liver (longitudinal orientation, midline, cutting through mid-portion of left lobe).

    • Slide over to image anteriorly or intercostally for right liver and kidney.

  • Example Images to Collect:

    • Longitudinal right kidney & right liver: Diaphragm, hepatic veins, portal veins, Glisten's capsule, GERRADA's capsule, renal pelvis, renal pyramids.

      • Orientation: Superior/Inferior, Anterior/Right Lateral, Posterior/Medial.

      • Note inferor pole of kidney appears fuzzy due to bowel overlap.

      • Rib shadowing indicates intercostal scanning.

    • Transverse kidney: Turn probe 90 degrees counterclockwise (notch to patient's right).

      • Kidney appears C-shaped, more rounded/oval.

      • Pyramids, pelvic fat visible; vessels (renal artery/vein) visible with color Doppler.

      • Main portal vein may be visible; right lobe, turning into left lobe medially.

    • Midline Vasculature Options (choose one):

      • Aorta: Separation between liver and aorta; celiac/SMA branching with color Doppler.

      • IVC: Touches posterior liver wall; hepatic veins entering IVC, going into right atrium with color Doppler.

  • Live Scan Example (Liver Ultrasound) (78:25):

    • Patient Position: Supine, legs bent, arm above head to expose ribs.

    • Probe Placement: 9th or 10th rib space, mid-axillary line.

    • Probe Indicator: Towards patient's head.

    • Standard Ultrasound Setting: Indicator on screen on left side.

    • Identify from Superior to Inferior:

      • Lung: Most superior, shows mirror artifact (normal, due to sound scattering by air at diaphragm).

      • Diaphragm: Hyperechoic (bright) structure below lung, above liver.

      • Liver: Grayish appearance.

      • Right Kidney: Below liver.

    • Morrison's Pouch: Space between liver and right kidney where free fluid (ascites or blood) accumulates.

      • Scan towards liver tip to check for fluid.

    • Hepatomegaly Measurement: From top of diaphragm to inferior edge of liver.

    • Echogenicity: Bright for chronic scarring/cirrhosis; dark for hepatitis (fluid/inflammation).

15. Supplemental Materials (81:25)
  • List of videos, diagrams, instructional information on abdominal scanning.

  • Resource for review before lab.