Anatomy, Perfusion, and Function
30%of exam
Liver AnatomyBiliary SystemPancreas & SpleenKidney & UrinaryVasculatureDoppler & Perfusion
Pathology, Vascular Abnormalities, Trauma, Postop
42%of exam
Liver PathologyBiliary PathologyRenal Pathology & BosniakVascular Abnormality SignsTrauma & TransplantAbdominal Wall & Hernias
Abdominal Physics
8%of exam
Clinical Care, Practice, and QA
20%of exam
Clinical Care & PrepMeasurements & ProceduresPatient CommunicationConsent & Safety
Quick Facts
- Exam Code
- AB
- Credential
- RDMS Abdomen
- Questions
- ~165
- Time
- 3 hours
- Pass Score
- 555/700 scaled
- Format
- CBT, Pearson VUE
- Level
- Specialty (post-SPI)
- Blueprint
- v24.1
CBD Diameter Age Rule
Six mm normal, plus one mm per decade after sixty
Baseline: 6mm normalAdd 1mm per decadePost-chole: up to 10mm
CBD vs Portal Vein
CBD
- Under 6mm normal
- Anterior to portal vein
- Anechoic tubular structure
Portal Vein
- Under 13mm normal
- Hepatopetal flow direction
- Thicker echogenic walls
Diameter and location differ
Liver Anatomy & Measurements
- Liver span (MCL)
- 13-15.5 cm normal
- Hepatomegaly threshold
- >15.5 cm span
- Couinaud system
- 8 functional liver segments
- Main lobar fissure
- Separates right, left lobes
- Ligamentum teres
- Falciform ligament remnant
- Caudate lobe
- Segment I, spared cirrhosis
Biliary System Reference
- CBD normal diameter
- Under 6 mm
- Post-cholecystectomy CBD
- Up to 10mm
- CBD age rule
- +1mm per decade after 60
- GB wall thickness
- Under 3 mm normal
- GB length normal
- Under 10 cm
- CBD measurement technique
- Inner wall to inner wall
Pancreas & Spleen Values
- Pancreatic duct normal
- Under 2-3 mm
- Pancreas head location
- Anterior to IVC
- Spleen length normal
- Under 12 cm
- Splenomegaly threshold
- Over 12-13 cm length
- Accessory spleen
- Near splenic hilum
Kidney & Urinary Values
- Renal length normal
- 9 to 12 cm
- Renal RI normal
- Under 0.7
- Elevated renal RI
- Over 0.7 abnormal
- Cortex echogenicity
- Hypoechoic to liver
- Renal sinus fat
- Most echogenic region
- Bladder wall normal
- Under 3mm distended
Abdominal Vasculature Reference
- Aorta normal diameter
- Under 2-3 cm
- AAA threshold, men
- 5.5 cm repair
- AAA threshold, women
- 5.0 cm repair
- Portal vein normal
- Under 13 mm
- Portal flow direction
- Hepatopetal, toward liver
- Hepatic vein waveform
- Triphasic normal pattern
- Portal vein waveform
- Monophasic, undulating flow
Doppler & Perfusion Patterns
- Hepatic artery RI
- 0.55 to 0.7
- TIPS velocity, normal
- 90 to 190 cm/s
- TIPS velocity, stenosis
- Under 50-60 cm/s
- Renal artery PSV
- Over 180 cm/s stenosis
- RAR ratio
- Over 3.5 significant
Exam Domain Weight Order
30, 42, 8, 20: anatomy, pathology, physics, clinical
30%: anatomy and perfusion42%: pathology and vascular8%: abdominal physics20%: clinical care and QA
Cholecystitis vs Choledocholithiasis
Cholecystitis
- GB wall thickening
- Positive Murphy sign
- Pericholecystic fluid present
Choledocholithiasis
- Dilated CBD diameter
- Stone with shadowing
- Possible jaundice
Gallbladder versus duct pathology
Organ Finding Decision Logic
- RUQ pain, positive Murphy→Evaluate gallbladder(Cholecystitis workup)
- Jaundice with painless GB→Consider pancreatic mass(Courvoisier sign)
- Flank pain, hydronephrosis seen→Evaluate ureter and stone(Obstruction workup)
- Trauma with hypotension→FAST for free fluid(Check Morrison pouch first)
- Cirrhosis with ascites→Doppler the portal vein(Check flow direction)
- Renal cyst identified→Apply Bosniak category(Guides management plan)
- Post-transplant rising RI→Suspect rejection(Compare to prior scan)
- Testicular pain, absent flow→Suspect torsion(Refer urgently)
Liver Pathology Patterns
- Fatty liver
- Diffusely hyperechoic, poor penetration
- Cirrhosis appearance
- Nodular, coarse, small liver
- Hemangioma appearance
- Hyperechoic, well-defined mass
- HCC appearance
- Variable, mosaic pattern
- Liver abscess
- Complex, thick-walled collection
- Budd-Chiari syndrome
- Hepatic vein thrombosis
Bosniak Categories One Through Four
I benign, II mild, III surgical, IV cancer
I: simple benign cystII: minimally complex, benignIII: indeterminate, needs surgeryIV: clearly malignant lesion
Hemangioma vs HCC
Hemangioma
- Hyperechoic, well-defined mass
- Peripheral nodular enhancement
- Common, benign lesion
HCC
- Variable, mosaic pattern
- Cirrhotic liver background
- Elevated AFP marker
Benign versus malignant mass
Biliary Pathology Signs
- WES sign
- Wall-echo-shadow, stone-filled GB
- Sonographic Murphy sign
- Pain under probe pressure
- Cholecystitis triad
- Stones, wall thickening, Murphy
- Courvoisier sign
- Painless, palpable dilated GB
- Klatskin tumor
- Hilar bile duct mass
- Choledocholithiasis
- CBD stone with shadowing
Gallbladder Sonographic Sign Names
WES means stones; Murphy means pain; Courvoisier means cancer
WES: wall-echo-shadow signMurphy: pain on pressureCourvoisier: painless dilated GB
RAS vs Nutcracker Syndrome
Renal Artery Stenosis
- PSV over 180 cm/s
- RAR over 3.5
- Arterial origin narrowing
Nutcracker Syndrome
- Left renal vein compressed
- Between aorta and SMA
- Causes hematuria symptoms
Artery versus vein compression
Renal Pathology & Bosniak
- Bosniak I
- Simple benign cyst
- Bosniak II
- Minimally complex, benign
- Bosniak IIF
- Follow-up imaging needed
- Bosniak III
- Indeterminate, surgical evaluation
- Bosniak IV
- Clearly malignant lesion
- Hydronephrosis grading
- Mild to severe
- AML
- Angiomyolipoma, echogenic fat mass
TIPS Normal vs Stenosis
Normal TIPS
- 90 to 190 cm/s
- Hepatopetal portal flow
- Stable over time
Stenotic TIPS
- Under 50-60 cm/s
- Reversed portal flow
- Symptoms recur again
Velocity range confirms patency
Vascular Abnormality Signs
- Aliasing
- Doppler wraparound artifact
- Twinkle artifact
- Behind echogenic renal stones
- Renal vein thrombosis
- Enlarged kidney, absent flow
- Nutcracker syndrome
- Left renal vein compression
- Portal hypertension signs
- Varices, splenomegaly, ascites
Trauma & Transplant Findings
- FAST exam
- Four views, free fluid
- Morrison's pouch
- Hepatorenal recess, first fluid
- Transplant rejection sign
- Elevated RI, swelling
- ATN
- Common early transplant complication
- Perinephric fluid
- Transplant complication finding
- Splenic trauma
- Subcapsular fluid, laceration
Abdominal Wall & Hernias
- Inguinal hernia
- At inguinal ligament level
- Ventral hernia
- Midline abdominal wall defect
- Incisional hernia
- At prior surgical site
- Valsalva maneuver
- Provokes hernia bulge
Color vs Power Doppler
Color Doppler
- Shows flow direction
- Angle dependent signal
- Aliasing can occur
Power Doppler
- Shows flow presence
- More sensitive overall
- No direction shown
Direction versus sensitivity tradeoff
Transducer Selection Logic
- Deep abdominal organs→Curvilinear(Lower frequency)
- Superficial thyroid or scrotum→Linear(Higher resolution)
- Cardiac or intercostal views→Phased array(Small footprint)
- Suspect gallstone shadowing→Increase frequency(Improve resolution)
- Poor penetration, obese patient→Lower frequency(Increase depth)
- Assess flow direction→Color Doppler(Shows direction)
- Confirm flow presence only→Power Doppler(No direction shown)
- Quantify velocity waveform→Pulsed wave Doppler(Spectral trace shown)
Physics & Instrumentation
- Curvilinear transducer
- Deep abdominal imaging
- Linear transducer
- Superficial structure imaging
- Harmonic imaging
- Reduces noise, artifact
- Compound imaging
- Multiple angle averaging
- Color Doppler
- Shows flow direction
- Power Doppler
- Sensitive, no direction
- Pulsed wave Doppler
- Spectral waveform analysis
Common Imaging Artifacts
- Shadowing artifact
- Behind stones, calcifications
- Comet tail artifact
- Reverberation, adenomyomatosis sign
- Mirror image artifact
- Duplicated across diaphragm
- Spectral broadening
- Turbulent or stenotic flow
- Aliasing fix
- Increase scale or PRF
Clinical Care & Patient Prep
- Biliary exam prep
- NPO 6-8 hours
- Full bladder prep
- Pelvic, renal imaging
- HIPAA
- Protects patient privacy
- Informed consent
- Required before procedures
- Correlate labs
- LFTs, renal function
- Multiple scan positions
- Decubitus, supine, upright
Measurements & Procedure Support
- Doppler angle
- Under 60 degrees ideal
- Sample volume gate
- Placed within vessel lumen
- Needle guidance
- In-plane or out-of-plane
- Pre-procedure consent
- Verify site and laterality
- Post-procedure check
- Assess for complications
Common Traps
CBD ≠ Portal Vein
CBD: under 6mm, anechoic ≠ Portal vein: under 13mm, thick-walled
Murphy Sign ≠ Courvoisier Sign
Murphy: gallbladder is painful ≠ Courvoisier: gallbladder is painless
Renal RI ≠ RAR Ratio
RI: intrarenal resistive index ≠ RAR: renal-to-aortic velocity ratio
Color Doppler ≠ Power Doppler
Color: shows flow direction ≠ Power: shows flow presence
Hepatopetal ≠ Hepatofugal Flow
Hepatopetal: flow toward liver ≠ Hepatofugal: flow away, reversed
Scored ≠ Pretest Questions
Scored questions count toward pass ≠ Pretest questions do not count
Twinkle Artifact ≠ True Flow
Twinkle: mimics vascular flow ≠ True flow: consistent Doppler signal
Last Minute
- 1.Weights: 30, 42, 8, 20 percent
- 2.CBD normal is under 6mm
- 3.Portal vein normal under 13mm
- 4.Spleen normal length under 12cm
- 5.Renal RI normal under 0.7
- 6.AAA repair threshold is 5.5cm
- 7.TIPS velocity 90 to 190
- 8.WES sign means gallstones present
- 9.Murphy sign means acute cholecystitis
- 10.Bosniak IV means clearly malignant
- 11.FAST checks four fluid windows
- 12.Passing score is 555 scaled
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