CT TRIPHASIC LIVER

Introduction 

A CT Triphasic Liver scan is a specific contrast-enhanced computed tomography examination of the liver. It captures images during three critical phases of blood flow: arterial, portal venous, and delayed. This is done to detect, evaluate, and characterize lesions and vascular structures of the liver. This modality has a pivotal role in diagnosing liver tumours, complications of cirrhosis, and evaluating candidacy for operative interventions.  

What is a CT Triphasic Liver? 

This scan requires the use of intravenous contrast followed by imaging in three timed phases:  

• Arterial Phase (20–30 seconds) – Enhancements of hepatic arteries and hyper vascular lesions are visualized. 
• Portal Venous Phase (60–70 seconds) – Liver parenchyma and portal vein enhancement are at their optimal value. 
• Delayed Phase (3-5 minutes) – Detection of washout patterns as well as changes in fibrotic or excretory tissues are possible. 

These phases allow for differentiation of benign from malignant lesions and evaluation of liver function and perfusion.

• Enhancement pattern of liver lesions 
• Patency of hepatic artery branches, portal vein, and hepatic veins 
• Cirrhosis with nodules or fibrosis presence 
• Detection of intrahepatic biliary duct dilation 
• Lymphadenopathy or peritoneal metastasis 

• Distinction between benign and malignant hepatic tumours 
• Surveillance of the liver or any known hepatic malignancy 
• Assess inflicted trauma and determine bleeding 
• Evaluate liver vascular flow prior to surgery 

When and Who Needs This Scan? 

Indications: 

• Hepatocellular carcinoma (HCC) or metastases suspicion 
• Characterization of liver lesion 
• Surveillance of cirrhosis 
• Assessment for potential liver transplant candidacy 
• Evaluation of hepatic vascular anomalies 

Patient Demographics: 

• Patients with chronic liver disease or cirrhosis 
• Patients with cancer and known or suspected metastatic disease in the liver 
• Patients with liver function tests outside the normal range 
• Patients undergoing liver resection or transplant 

Benefits of Taking the Test

• Captures structural and vascular details of the liver. 
• Achieved quickly and non-invasively. 
• Important for staging and diagnosing liver cancer. 
• Assists in formulating treatment and surgical strategies. 

Conditions Diagnosed

• Hepatocellular carcinoma (HCC). 
• Liver metastasis. 
• Haemangioma, focal nodular hyperplasia (FNH). 
• Cirrhosis with regenerative nodules. 
• Hepatic abscesses or cysts. 
• Thrombosis or aneurysms in the portal vein. 

• No food 4-6 hours prior to testing. 
• Encouraged hydration before and after procedure. 
• Allergies to the contrast or kidney issues should be indicated to the radiology department. 

Pre-requisites 

• Need a referral from the treating clinician. 
• Serum creatinine check if contrast is included. 
• Must obtain consent for injection of the contrast material. 

Best time to take the test 

• According to the clinician’s timetable. 
• Done preferably in the morning to allow immediate interpretation of results. 

Eligibility 

• Exclusions pertain to those who are pregnant. 
• Stipulations apply for use in renal failure or known allergy to the contrast. 

Procedure 

• Contrast injected through an established IV line. 
• Patient lays supine on the CT scanner. 
• Imaging is done in three phases: arterial, portal venous, and delayed. 
• Total scanning time is about 15 to 25 minutes. 
• A radiologist has the responsibility of reconstructing and interpreting the images. 

Caution 

• Remain passive and precisely adhere to breath-holding commands  
• Indicate any feelings of warmth, nausea, or itching post contrast injection.  
• Consume fluids post scan to assist in flushing out the contrast media.