Last Updated on January 12, 2023 by Mohamad Izwan

Anatomy of Liver

Image taken from Encyclopaedia Britannica, Inc.

Appearance of CT Liver - Late Arterial Phase (LAP) Images

Appearance of CT Liver - Portal Venous Phase (PVP) Images

Examination Overview

Protocol Structure

00_Liver3Phase (Adult)

    • Topogram
    • Non Contrast (Above diaphragm to the ischial rami)

Bolus Tracking

    • Pre Monitoring
      • (At the level of diaphragm)

Contrast

    • Monitoring
      • (At the level of diaphragm)
      • Contrast triggering at the abdominal aorta
      • Triggered when achieve 100HU
    • Liver LAP
      • (above diaphragm to the end of liver)
    • Venous Phase
      • (above diaphragm to the ischial rami)
    • Delayed 5 Minutes (optional)
      • Liver (above diaphragm to the end of liver)
      • Full abdomen (above diaphragm to the ischial rami)

Topogram

  • Position the patient in head first supine position.
  • Align the patient in Mid-Sagittal plane of the table.
  • Position the transverse laser light beam at the level of mid of sternum to start the topogram.

Topogram Parameters

  • Topogram length: 512 mm
  • Slice: 0.6 mm
  • Scanning direction: Craniocoudal
  • Tube position: Top
  • Stop the topogram scanning when the scanning reach / pass over the inferior ischial ramus.

Non Contrast

  • Plan the Scan FOV (SFOV) box at topogram image.
  • Set the top line at the level of upper diaphragm.
  • Set the bottom line at the level of inferior ischial ramus.
  • Ensure the lateral line to cover patient’s body outline.
  • Remind the patient before scanning as the breathing instruction will be given.

Scanning Parameters

  • kV: 100 kV
  • mAs: Tube Current Modulation (TCM)
  • Scanning Direction: Craniocaudal
  • Scan Delay: 4 s
  • Slice: 5.0mm
  • Image Comment: Pre-Contrast
  • Pitch: 0.6
  • Quality Reference mAs : 230

Reconstruction of Liver Non Contrast

Recon 1Recon 2
NameNon Contrast 5.0 B30fNon Contrast 1.0 B20f
Slice Thickness5.0 mm1.0 mm
Increment5.0 mm0.7 mm
KernelB30f Medium SmoothB20f Smooth
WindowingAbdomenAbdomen

Contrast

Type of contrast used:

    • Non-ionic iodinated contrast media
    • 300 I mg/mol

Needle Placement Test:

    • Flow Rate: 3.5 ml/sec
    • Volume of Normal Saline: 15 ml

Contrast Injection:

    • Volume of Contrast Media:
      • 100 ml (normal body type)
    • Volume of Normal Saline: 50 ml

Injector setup for Normal Body Size

Contrast Normal Saline
Flow rate3.0 ml/sec3.0 ml/sec
Contrast Volume100 ml50 ml

Bolus Tracking

Pre Monitoring

  • Set the scanning line at the level of diaphragm.

Monitoring

  • Ensure the scanning line from Pre-Monitoring is at the level of diaphragm.
  • Ensure the lateral line to cover patient’s body outline.
  • Draw ‘Triggering ROI’ on Abdominal Aorta (left-hand click on Siemens CT console).
  • Set:
    • Delay: 10 seconds
    • HU to triggered : 100HU

Post Contrast Scan Planning

Liver LAP

  • Plan the Scan FOV (SFOV) box at topogram image.
  • Set the top line at the level upper diaphragm.
  • Set the bottom line at the level of end of liver.
  • Ensure the lateral line to cover patient’s body outline.
  • Remind the patient before scanning as the breathing instruction will be given.
  • Delay: 10 seconds (after Bolus Tracking).

Venous Phase

  • Plan the Scan FOV (SFOV) box at topogram image.
  • Set the top line at the level upper diaphragm.
  • Set the bottom line at the level inferior ischial ramus.
  • Ensure the lateral line to cover patient’s body outline.
  • Remind the patient before scanning as the breathing instruction will be given.
  • Delay: 25 seconds (after Liver LAP).

Reconstruction of Liver LAP

Recon 1Recon 2
NameLiver LAP 5.0 B30fLiver LAP 1.0 B20f
Slice Thickness5.0 mm1.0 mm
Increment5.0 mm0.7 mm
KernelB30f medium smoothB20f smooth
WindowingAbdomenAbdomen

Reconstruction of Venous Phase

Recon 1Recon 2
NameVenous Phase 5.0 B30fVenous Phase 1.0 B20f
Slice Thickness5.0 mm1.0 mm
Increment5.0 mm0.7 mm
KernelB30f medium smoothB20f smooth
WindowingAbdomenAbdomen

Delayed 5 Minutes (Optional)

  • Liver
    • Plan the Scan FOV (SFOV) box at topogram image
    • Set the top line at the level of above diaphragm.
    • Set the bottom line at the level of end of liver.
    • Remind the patient before scanning as the breathing instruction will be given.
  • Full abdomen
    • Plan the Scan FOV (SFOV) box at topogram image
    • Set the top line at the level of above diaphragm.
    • Set the bottom line at the level of inferior ischial ramus.
    • Remind the patient before scanning as the breathing instruction will be given.
  • Ensure the lateral line to cover patient’s body outline.

Reconstruction of Delayed

Recon 1Recon 2
NameDELAY 5.0 B30fDelay 1.0 B20f
Slice Thickness5.0 mm1.0 mm
Increment5.0 mm0.7 mm
KernelB30f Medium SmoothB20f Smooth
WindowingAbdomenAbdomen

Multiplanar Reconstruction (MPR)

Coronal LAP IV

  • Image Thickness: 3.0 mm
  • Number of Image: 19
  • Coverage: Anterior to Posterior of abdomen

Coronal PVP IV

  • Image Thickness: 3.0 mm
  • Number of Image: 19
  • Coverage: Anterior to Posterior of abdomen

Series of Images Send to PACS

  1. Topogram
  2. Non Contrast 5.0 B30f
  3. Non Contrast 1.0 B20f
  4. LAP 1.0 B20f
  5. LAP 5.0 B30f
  6. Venous Phase 5.0 B30f
  7. Venous Phase 1.0 B20f
  8. Delayed 15 Min 5.0 B30f
  9. Delayed 15 Min 1.0 B20f
  10. Patient Protocol
  11. COR LAP IV
  12. COR PVP IV