Abdominal Ultrasound Abdominal Ultrasound: Objectives • Review normal sonographic anatomy of abdominal organs • Review vascular anatomy where indicated Ulrike M. Hamper, M.D.; M.B.A. • Present some common and basic Russell H. Morgan Department of Radiology and pathological condition Radiological Sciences Johns Hopkins University School of Medicine • Live scanning portion afterwards Baltimore, Maryland Acknowledgements: Liver Thanks to: • Largest solid organ in normal abdomen • Occupies most of the right upper quadrant • M. Robert De Jong, RDMS, RVT, FAIUM, • Right lobe (largest) FSDMS – Johns Hopkins – anterior and posterior segment- delineated by interlobar fissure, gallbladder, middle hepatic vein (MHV) • and • Left lobe • Dr. Leslie Scoutt, Yale University, School – Medial and lateral segment- delineated by ligametum of Medicine teres and left hepatic vein (LHV) • Caudate lobe (smallest) for supplying some of the images – Delineated by the fissure for the ligametum venosum Falciform Ligament Liver Sonography • Fasting 6-8 hours prior to exam • Transducer dependent L M L on patient body habitus R • Technique – Normal liver brighter than the renal cortex • Measures 13-17cm in length Surface Anatomy Segmental Anatomy- – Right mid-clavicular Ligamentum teres line 1 Liver Anatomy - Right Lobe Right Lobe Divisions • Right Hepatic Vein – Divides right lobe into RHV segments Anterior L K • Anterior • Posterior Posterior Sagittal Transverse Liver - Left Lobe Main Lobar Fissure • One of the main • Right/left separation dividers of the liver into fairly equal – Middle hepatic vein MHV right & left lobes – (MHV) – Main lobar fissure • Seen as a white line extending from the portal hepatis to the gallbladder neck Division Right and Left Lobe Liver- Left Lobe • Main lobar fissure (yellow arrow) • Middle hepatic (turquoise arrow) • Divided into medial and lateral segments Medial Lateral – Left hepatic vein – Ligamentum teres LT LT • Echogenic round structure RT RT 2 Liver - Caudate Lobe Hepatic Veins • Sagittal Borders – Inferior • Right hepatic • Main portal vein (MPV) vein – Posterior • Middle hepatic • Inferior vena cava vein (IVC) MPV • Left hepatic vein – Anterior IVC • Ligamentum Venosum (arrow) Hepatic Veins Main Portal Vein LHV MHV RHV Portal Vein Division Portal Vein • Portal vein LPV – Hepatopetal flow • MPV divides – Flow into liver MPV within the liver into RPV – Right portal • Branches course within hepatic segments vein-short – Left portal vein- • Doppler signal longer – Continuous flow 3 Riedel’s Lobe - Normal Variant Liver Cyst- Benign Mass • Anechoic, posterior acoustic enhancement • More common in women • Presents clinically as – Hepatomegaly – Right upper quadrant (RUQ) mass • Normal echotexture • Elongation of right " inferior lobe – Tongue like projection – Finger like projection Metastatic Breast Cancer Liver Metastases from Lung Cancer Hepatocellular Carcinoma Gallbladder-Anatomic Location • Inferior aspect of the liver • Medial and anterior to right kidney • Lateral and anterior to IVC • Fundus, body, neck • Junctional fold - kink near neck • Phrygian cap – kink near fundus 4 Sonographic Technique Gallbladder • Patient fasting, H2O permitted • Supine: longitudinal & transverse views Fundus Body • Decubitus: Right side up views Neck • Erect views • Identify local tenderness Normal Gallbladder Gallbladder Measurements Sagittal Transverse • 10 cm length 4 cm transverse • 4 cm transveransv Superior Inferior Lateral Medial Gallbladder Measurements Gallbladder- Junctional Folds • Wall thickness < 3 mm * * * 1mm 7mm 5 Gallbladder – Fundal Fold Gallstones • Folds – Phrygian cap: fundus folds on itself • Often found in asymptomatic patients (10% of US population) • Acute or chronic cholecystitis • Dense echogenic structure • > 2-3 mm - posterior acoustic shadowing Gallstones Gallstones • Movement on RSU or erect view • Stone filled GB - no surrounding echo-free bile • Floating gallstones • Adherent gallstones (DDX: polyp, tumor)"" Gallstone Gallstones • They are mobile Supine Right side up decubitus 6 Gallstones: Shadowing Gallstone versus Polyp • Size dependent Gallstone with Polyp - no shadow- – > 3 mm acoustic shadow non-mobile • Independent of the composition Acute Cholecystitis : US Findings Acute Cholecystitis • Most common cause of RUQ pain • Gallstones • > 90% of cases due to obstruction of • Acute, focal pain the cystic duct or neck of gallbladder • GB wall thickening, > 3 mm • Leads to: – distension • Peri GB - fluid collections – ischemia Gallstones – inflammation Positive sonographic Murphy sign Combination of findings • – superinfection – PPV: 92% – necrosis – NPV: 95% Ralls, Radiology: 1985 – perforation ACUTE CHOLECYSTITIS Acute Cholecystitis Stone in neck 7 Gallbladder Carcinoma Gallbladder Carcinoma • Focal mass near gallbladder fundus • Thick gallbladder walls • Central vascularity on CDUS • Projection of cancerous mass into lumen - like polyps or stones • Ill-defined large mass in gallbladder bed Biliary Tree Extrahepatic Bile Ducts • Bile duct lies anterior & lateral to the MPV • Only a small portion seen within liver • Lateral (to right) of Hepatic artery (HA) • Common bile duct (CBD): – anterior to portal vein – anterior and to the right of hepatic artery HA • Occasionally small portion CBD of biliary tree outside of porta hepatis visible PV • CBD: 6 - 7 mm upper limits of normal – ↑ w/ age, s/p cholecystectomy – debatable Extrahepatic Bile Ducts Normal Porta Hepatis Anatomy • Common hepatic duct – above cystic duct insertion • Common bile duct – Below cystic duct insertion • We usually do not see cystic the cystic duct 8 Normal Porta Hepatis Anatomy Intrahepatic Bile Ducts • Right and left hepatic ducts run anterior to portal veins • Peripheral ducts CBD GB variable HA MPV Biliary Obstruction Biliary Obstruction • Dilated CBD and intrahepatic ducts • “Double barrel shotgun” • Large stone in distal CBD (arrow) • “Parallel channel” sign • Stones in CBD Mass within bile ducts CBD • CBD • Mass porta hepatis (ca or nodes) Renal Ultrasound Renal Anatomy • Adult Size • Normal renal parenchyma: – 9 - 13 cm length – < echogenic than liver – 4 -5 cm wide – Dense central sinus echoes (fat) – Medullary zone (pyramids) – 2.5 -3 cm AP – < echogenic than cortex • Neonate – Echogenic capsule – 4.5 -5 cm long • NORMAL SIZE: 8 -13 cm (adult) 4.5 - 5 cm (birth) 9 Normal Kidney - Sagittal View Normal Renal Anatomy 1. Cortex (the outer c-shaped thick rim) 2. Medulla (the renal pyramids) 3. Sinus (central area) 1 2 3 Normal Renal Anatomy Normal Renal Anatomy • Sinus • Sinus (hyperechoic) – Major & minor • Medulla (almost calyces anechoic) – Pelvis • Cortex (hypoechoic) – Artery & vein • Capsule (usu not seen) – Fat • Perirenal fat (variable – Nerves & lymphatics echogenicity) Renal Cortex Renal Pyramids Hypo- or isoechoic to the liver or spleen • Triangular or pyramidal hypoechoic areas 10 Renal Sinus Scanning Technique- Sagittal • Echogenic central portion of kidney – Due to multiple reflections – Collecting ducts – Fat – Lymphatics Scanning Technique - Transverse Normal Kidney Renal Measurements Renal Cortical Echogenicity • Vary with age, height, weight, sex • Renal medulla < cortex < liver/spleen • Renal lengths: 9-13 cm • Right and left kidney should be within 2 cm in length – Left kidney usually slightly bigger than right • Size decreases with age • Compensatory hypertrophy- if renal agenesis 11 Renal Cortical Echogenicity Renal Blood Supply • Increased – ↑ corticomedullary differentiation • Renal artery – ↑ relative to liver/spleen • Segmental artery • Interlobar artery normal increased • Arcuate artery • Interlobular artery Blood Supply Renal Blood Supply • Main Renal artery • Renal artery • Segmental artery Blood Supply Blood Supply • Renal artery • Renal artery • Segmental artery • Segmental artery • Interlobar artery • Interlobar artery • Arcuate artery 12 Blood Supply Renal Vasculature • Renal artery Color Doppler US 3- D US • Segmental artery • Interlobar artery • Arcuate artery • Interlobular artery Renal Calculi Renal Calculus • Bright echogenic focus with acoustic shadowing • Shadowing independent of composition, dependent on size • 3 mm should shadow • Try higher or lower frequency transducer Hydronephorosis Hydronephrosis • Obstructions at ureteropelvic junction (UPJ), ureterovescicle junction (UVJ, ladder outlet • Dilated pelvocalyceal system ureter • Dilated ureter • Cortical atrophy 13 Hydronephrosis Hydronephrosis • Do not confuse with vessels • Do not confuse with vessels – use color Doppler US – use color Doppler US Benign Mass - Simple Renal Cyst Benign Mass - Renal Cyst • Anechoic, fluid filled, posterior enhancement • Anechoic sharply defined renal mass (C) • Arising from the kidney (K) C C C C K K Renal Cell Carcinoma Spleen • Mildly echogenic left renal mass • Intraperitoneal organ in the left upper • Minimal vascularity on CDUS quadrant • In continuity with the diaphragm, left kidney, splenic flexure, stomach and tail of the pancreas • Homogenous echotexture on US • More echogenic than the liver or the left kidney • Normal measurements: 12 x 6 x 4cm 14 Spleen Splenomegaly • > 12 cm in adults Focal Splenic Mass - Lymphoma Pancreas • Slightly more echogenic than liver • Size: Head- 2.7 +/- 0.7 cm Body- 2.2 +/- 0.7 cm Tail- 2.4 +/- 0.7 cm Normal Pancreas Pancreas US- Technique • Fast 6-8 hours to reduce bowel gas • 3.5 - 5 MHz curved array transducer • Pancreatic tissue brighter and coarser ST • than liver tissue • Scan on deep " P inspiration SV P P • Left lobe as " IVC AO acoustic window SMA • Oral