CT TRIPHASIC ABDOMEN

CT Triphasic Abdomen Overview

Introduction 

The CT Triphasic Abdomen is a specific imaging study that involves the use of contrast to evaluate abdominal organs, specifically the liver, pancreas, kidneys, and vascular structures, in three different blood flow phases: arterial, venous, and delayed. It is effective for tumour detection, vascular disorders, and liver lesions and is routinely performed in oncology, hepatology, and pre-transplant evaluations. 

What is a Triphasic CT Abdomen? 

A triphasic CT scan consists of three sets of images taken after intravenous contrast is administered:  

• Arterial Phase: Captured roughly 20-30 seconds post-contrast administration to visualize the arteries.  
• Venous (Portal) Phase: Captured approximately 60-70 seconds post-injection to assess the organs and veins.  
• Delayed Phase: Captured 3-5 minutes post injection to identify slow-enhancing lesions or excretory changes.  

These phases enable the assessment of abdominal structures more precisely about their vascularity and enhancement patterns. 

Parameters Considered

• Pattern of liver enhancement over the phases of examination  
• Presence of lesions, cysts, or tumours of the abdominal organs  
• Patency of visceral abdominal vasculature  
• Biliary or urinary obstruction  
• Lymph nodes or peritoneal spread  

Reasons for the Test

• Lesion detection and characterization in the liver  
• Other malignancies in the abdomen  
• Peripheral vascular and aneurysm abnormality identification  
• Evaluate trauma  
• Assess treatment response in malignancy  

When and Who Needs This Scan? 

Indications: 

• Considered suspicious for primary or metastatic liver tumours 
• Characterization of lesions in pancreas, kidneys, or adrenal glands 
• Assessment of abdominal trauma/ bleeds 
• Preoperative liver donor evaluation  
• Surveillance of hepatic lesions and malignancies  

Patient Demographics: 

• Oncology patients  
• Patients with chronic liver conditions, cirrhosis  
• Patients with abnormal liver function tests and unexplained abdominal pain  
• Organ transplant donors and recipients  

Benefits of Taking the Test

• Evaluating organs from multiple phases in high resolution has been done. 
• Vascularity and staging of lesions are precisely determined. 
• As a surgical and oncological decision aid, this form of imaging is vital. 
• This form of imaging is quick, safe, and has an extremely low accessibility barrier.  

Conditions Diagnosed

• Hepatocellular carcinoma (HCC) 
• Liver metastases or haemangiomas 
• Renal cell mantle carcinoma 
• Tumours of the pancreas 
• Aneurysms, pseudoaneurysms, or vascular malformations. 
• Carcinoma of lymph nodes or peritoneal surfaces. 

Preparation

• Fasting for 4-6 hours before the scan is required. 
• Sufficient water intake before and after the procedure is essential. 
• Disclosure of kidney function and contrast allergy history is important. 

Pre-requisites 

• Healthcare referral is required. 
• Recent serum creatinine test is required, especially for elderly and renal compromised patients. 
• Consent for contrast use is mandatory. 

Best Time to Take the Scan 

• Needs to be scheduled according to clinical urgency. 
• Morning appointments are preferred to optimize reporting and preparation time. 

Eligibility 

• All individuals of all ages are “safe” taking this scan.  
• “Risk Assessment” is needed in pregnancy, renal impairment, and iodine allergy. 

Procedure 

• Start an IV line for contrast injection.  
• Have the patient lie on the CT table in a supine position. 
• Contrast injection followed by the acquisition of scout images.  
• Capture three phases (arterial, venous, and delayed) at specified time intervals.  
• Approximate duration of the scan is 20-30minutes of prep included. 

Caution 

• Stay still and adhere to breath-holding protocols.  
• Allergies, renal issues, and pregnancy should be reported to the radiologist.  
• Possible side effects of contrast may include nausea, sensations of warmth, and a metallic taste.