Module · Abdomen
FUSIC Abdomen resources
25 scans, 10 directly observed, max 15 normals. Report regions in order: RUQ, LUQ, right kidney, left kidney, bladder/pelvis. Document diaphragm, organs, hydronephrosis, free fluid.
Probe & systematic approachCurvilinear probe, patient positioning, and the scan order.
Use the curvilinear probe (3.5–5 MHz). The larger footprint and lower frequency penetrate the abdomen better than a phased-array probe.
Scan order (matches the FUSIC Abdomen reporting form):
- RUQ — diaphragm, liver, Morrison’s pouch
- LUQ — diaphragm, spleen, splenorenal recess
- Right kidney — size, cortex, hydronephrosis grading
- Left kidney — size, cortex, hydronephrosis grading
- Bladder/pelvis — volume, free fluid in pelvis
RUQ — liver, diaphragm & Morrison’s pouchThe most important first view. Free fluid collects here first in the supine patient.
Probe in right midaxillary line, 8th–9th ICS, marker to head. Fan anterior and posterior to cover the full right lobe.
Diaphragm: Bright curvilinear structure above the liver. Mirror artefact (liver echoes appearing above diaphragm) = normal. True structures visible above diaphragm (no mirror effect) = pleural effusion or consolidated lung.
Liver parenchyma: Normal = homogeneous, slightly more echogenic than renal cortex. Hyperechoic (bright) = fatty infiltration. Flag focal masses for further imaging — not a FUSIC Abdomen competency to characterise.
Morrison’s pouch: The hepatorenal space — between the inferior right lobe and upper pole of the right kidney. The most dependent part of the peritoneal cavity in a supine patient. Free fluid collects here first. Any echo-free stripe between liver and kidney = free fluid.
LUQ — spleen & splenorenal recessHarder than RUQ — technique tips.
Place probe in left posterior axillary line, 8th–9th ICS, marker to head. This is the most posterior window — rolling the patient into right lateral decubitus helps significantly.
What to assess:
- Left diaphragm: Same as right side.
- Spleen: Homogeneous, moderately echogenic, crescent-shaped. Long axis >13 cm = splenomegaly.
- Splenorenal recess: Between inferior pole of spleen and upper pole of left kidney. Less dependent than Morrison’s — free fluid here suggests significant volume.
Kidneys — size, cortex & hydronephrosis gradingNormal appearances, how to measure, and the hydronephrosis grading you must know.
Image each kidney in long axis. Normal: 9–12 cm long, smooth outline, echogenic central sinus, hypoechoic cortex. Measure the long axis for the logbook.
Cortical echogenicity: Normal = less echogenic than adjacent liver/spleen. Equal to or brighter than liver = parenchymal disease.
| Grade | Hydronephrosis appearance |
|---|---|
| None | No dilatation of calyces or pelvis |
| Mild | Minimal calyceal separation; slight pelvic dilatation |
| Moderate | Clearly dilated calyces and pelvis; cortex preserved |
| Severe | Gross dilatation; cortex thinned or barely visible |
Bladder, stomach & pelvic free fluidVolume estimation, full stomach identification, and the Pouch of Douglas.
Place probe suprapubically, just above symphysis pubis. Bladder = echo-free rounded pelvic structure.
Bladder volume: Volume = 0.52 × L × W × H. Report as: Not seen / Small / Large.
Full stomach identification: Stomach lies superolateral to the bladder. Full stomach = echogenic contents or fluid level with “snowstorm” appearance. Important for anaesthetic risk assessment.
Prostate/cervix: Prostate = rounded echogenic structure behind bladder base (men). Uterus = oval structure posterior to bladder (women). Identifying these distinguishes normal pelvic anatomy from masses.
Pelvic free fluid: Collects in Pouch of Douglas (women) or rectovesical pouch (men) — posterior to bladder. Echo-free space surrounding uterus or posterior to bladder = free fluid.
Free fluid & guided paracentesisRecognising ascites and guiding safe drainage — including checking for vessels.
Free fluid conforms to spaces between organs, is echo-free (or echogenic if bloody/proteinaceous), and bowel floats centrally within it.
Distinguishing free fluid from bowel: Free fluid doesn’t peristalse and is truly compressible (displaces with pressure). Bowel bounces back and may peristalse.
Guided paracentesis site selection:
- Identify the deepest pool of ascites away from bowel and major vessels
- Use colour Doppler to check for vessels at the proposed insertion point — inferior epigastric artery runs medially; always stay lateral to the rectus abdominis
- Measure the distance from skin to fluid
- Mark the site with the patient in the drainage position
Pitfalls & difficult windowsWhat goes wrong and how to recover.
- Bowel gas: Causes acoustic shadowing and ring-down artefacts. Apply gentle pressure, or wait for peristalsis to displace gas.
- Post-operative abdomen: Adhesions, dressings, and surgical emphysema compromise views. Scan around the edges.
- Posterior acoustic enhancement behind bladder: Bright area behind bladder — normal (fluid lens effect). Not pathology.
- Confusing perirenal fat for collection: Fat is echogenic; a true collection is anechoic. Scan in multiple planes.
- Missing full stomach: Gastric emptying is delayed in ICU patients. Always assess the stomach before procedures.