CT TRIPHASIC LIVER

A CT Triphasic Liver scan is a highly specialized and powerful diagnostic imaging test designed to provide incredibly detailed, dynamic pictures of your liver. At Cadabam's Diagnostics, we use this advanced procedure to get a clear view of your liver, its complex blood supply, and any abnormalities that may be present. This scan involves a state-of-art CT scanner and the use of an intravenous (IV) contrast dye, which allows our radiologists to see how blood flows through the liver tissue and any lesions in real time. This information is critical for making an accurate diagnosis and guiding the best possible treatment plan for you.

What is a CT Triphasic Liver Scan?

The key to this advanced scan lies in its name: "triphasic," which means "three phases." Unlike a standard CT scan that might take one set of images, a triple phase CT scan of the liver captures images at three distinct and precisely timed intervals after the contrast dye is injected. This multi-phase approach is crucial for evaluating how liver lesions (tumors or other abnormalities) interact with the liver’s blood supply.

Here’s what each phase shows our radiologists:

• Arterial Phase: This first set of images captures blood flow when it is predominantly in the hepatic artery, which supplies oxygen-rich blood to the liver. Many cancerous tumors, especially Hepatocellular Carinoma (HCC), get most of their blood from this artery and will "light up" brightly during this phase.
• Portal Venous Phase: This second set of images is taken slightly later, as the contrast-filled blood flows into the portal vein. The portal vein supplies about 75% of the liver’s total blood flow. In this phase, the normal liver tissue is fully enhanced, providing a clear contrast against any lesions that may have washed out the dye.
• Delayed (or Equilibrium) Phase: The final set of images is captured a few minutes later. This phase shows how the contrast dye is distributed and washed out of both the normal liver tissue and any lesions. Certain types of tumors have a characteristic appearance in this phase, helping to confirm their identity.

By analyzing the enhancement patterns across these three phases, our specialists can confidently characterize liver lesions, often distinguishing between benign (non-cancerous) and malignant (cancerous) growths.

Types of CT Triphasic Liver Scan

The core triphasic CT liver protocol involving the arterial, portal venous, and delayed phases is standard. However, our expert radiologists at Cadabam's Diagnostics may slightly adjust the specific timing and scan parameters. These adjustments are tailored to the individual patient and the specific condition being investigated. For example, the protocol might be slightly optimized to look for Hepatocellular Carcinoma (HCC) versus a benign lesion like a hemangioma to ensure the most diagnostic information is captured.

A common question we hear is, "What does a triphasic CT of the liver show?" The answer lies in the detailed parameters our radiologists meticulously analyze across the three phases. This detailed analysis is the foundation of a CT scan for liver lesion characterization.

The radiologist looks for:

• Lesion Detection: The presence, exact location, precise size, and number of any abnormalities or lesions within the liver.
• Enhancement Pattern: Crucially, how a lesion "lights up" with contrast dye in each phase. For example, a lesion that shows strong enhancement (appears very bright) in the arterial phase is known as "arterial hyperenhancement."
• Washout Pattern: How quickly the contrast dye leaves the lesion compared to the surrounding normal liver tissue. A rapid "washout" in the portal venous or delayed phase is a key indicator for certain types of tumors.
• Capsule Appearance: The presence or absence of a distinct rim or "capsule" around a lesion, which can be another important diagnostic clue.
• Vascular Involvement: Whether a lesion is growing into or compressing nearby blood vessels, which is critical information for surgical planning.
• Background Liver: The overall health and appearance of the rest of the liver, including any signs of cirrhosis, fatty liver disease, or iron overload.

The reasons for performing this test are centered on obtaining definitive diagnostic information to guide critical medical decisions.

• Primary Reason: CT scan for liver lesion characterization. This is the most common reason—to accurately and non-invasively differentiate between benign (non-cancerous) tumors like hemangiomas, adenomas, and focal nodular hyperplasia (FNH), and malignant (cancerous) tumors.
• Diagnosis and Staging: To diagnose and determine the extent (stage) of Hepatocellular Carcinoma (HCC), the most common type of primary liver cancer.
• Evaluation of Metastases: To detect and characterize liver metastases, which are cancerous tumors that have spread to the liver from another part of the body (e.g., the colon or breast).
• Pre-Operative Planning: To provide surgeons with a detailed anatomical map before a liver resection (removing part of the liver) or a liver transplant.

When and Who Needs to Take a CT Triphasic Liver Scan?

A doctor typically recommends a CT Triphasic Liver scan in specific situations where detailed information about the liver is essential. You may be referred for this test if:

• An abnormality, such as a mass or lesion, was found on a previous imaging test like an ultrasound or a standard CT scan, and your doctor needs more information to determine what it is.
• You have a known chronic liver disease, such as cirrhosis, and require regular screening for liver cancer (Hepatocellular Carcinoma - HCC), as you are at a higher risk.
• Your medical team is planning for a procedure, such as liver surgery (resection), a transplant, or other targeted treatments like chemoembolization or ablation, and needs a detailed map of the liver and its blood vessels.

Benefits of Taking the Test

Choosing to have a CT Triphasic Liver scan provides several significant benefits:

• High Diagnostic Accuracy: It offers a very high degree of accuracy in identifying liver lesions, which can often eliminate the need for an invasive procedure like a liver biopsy.
• Guides Treatment: The detailed information provides your doctors with the crucial data they need to select the most effective and appropriate course of treatment.
• Precise Monitoring: It allows for the precise monitoring of a known liver condition over time or to assess how well a tumor is responding to therapy.

Illnesses Diagnosed with CT Triphasic Liver Scan

This specialized scan plays a vital role in diagnosing a wide range of liver conditions, including:

• Hepatocellular Carcinoma (HCC)
• Liver Metastases
• Benign tumors such as Hemangioma, Focal Nodular Hyperplasia (FNH), and Hepatic Adenoma
• Bile Duct Cancers (Cholangiocarcinoma)
• Various vascular abnormalities within the liver

Proper preparation is simple but essential for ensuring a successful scan. Our staff will provide you with specific instructions, which typically include:

• Diet: You will likely be asked to fast, meaning no food or drinks (except for small sips of water), for 4-6 hours before your scheduled appointment. This ensures your stomach is empty and helps produce the clearest images.
• Medication: Please inform our staff at Cadabam's Diagnostics about all medications you are currently taking. If you take medication for diabetes, such as Metformin, you will be given special instructions, as it may need to be paused temporarily around the time of the scan.
• Clothing: Wear comfortable, loose-fitting clothes. Try to avoid clothing with metal zippers, buttons, or buckles, as you may be asked to remove them or change into a hospital gown.

Pre-requisites

• You must have a referral (prescription) from your doctor to undergo a CT Triphasic Liver scan.
• A recent blood test to check your kidney function (specifically Serum Creatinine and eGFR) is mandatory before you can receive the IV contrast dye. This is a crucial safety step.

Best Time to Take the CT Triphasic Liver Scan

The scan can be performed at any time during our operational hours at Cadabam's Diagnostics. There is no specific biological time of day that is considered better than another for this test.

Eligibility

• Most adults are eligible for the scan.
• The scan is generally not recommended for pregnant women due to the radiation exposure, unless the medical benefit is considered absolutely essential and outweighs the risk.
• The test requires careful consideration for patients with poor kidney function or a known history of a severe allergic reaction to CT contrast dye.

Procedure for Taking a CT Triphasic Liver Scan

Understanding the triphasic CT liver protocol can help you feel more comfortable on the day of your test. Our compassionate team will guide you through every step.

• Step 1 (Check-in & Prep): When you arrive at Cadabam's Diagnostics, our front desk staff will confirm your details. You may be asked to change into a comfortable hospital gown.
• Step 2 (IV Line Placement): A trained technologist or nurse will place a small, thin plastic tube (an IV catheter) into a vein in your arm or hand. This is used to administer the contrast dye during the scan.
• Step 3 (Positioning): You will be asked to lie down comfortably on your back on the padded CT scanner table. The table will then gently and smoothly move you into the center of the large, donut-shaped CT scanner. The scanner is open at both ends, so you will not be fully enclosed.
• Step 4 (Scanning):
  • An initial plain scan (without contrast) may be performed first.
  • Next, the technologist, from an adjacent control room, will begin injecting the contrast dye through your IV line. As the dye enters your bloodstream, it is common to feel a warm sensation spreading through your body or notice a slight metallic taste in your mouth. This is a normal and harmless side effect that passes quickly.
  • The scanner will then begin taking rapid sets of images at the precisely timed intervals of the arterial, venous, and delayed phases.
  • To get the clearest possible pictures, the technologist will ask you to hold your breath for short periods (usually 10-15 seconds) while the images are being captured.
• Duration: The entire appointment, from check-in to completion, typically takes about 30-45 minutes. The actual scanning time is much shorter, often just a few minutes in total.

Caution Before Taking the Test

Your safety is our highest priority. It is absolutely crucial that you inform the technologist before your scan if you:

• Are pregnant or think you might be pregnant.
• Are currently breastfeeding.
• Have any known allergies, especially to iodine, shellfish, or have had a reaction to CT contrast dye in the past.
• Have any known kidney problems, have been diagnosed with renal failure, or are on dialysis.
• Have diabetes, especially if you are taking Metformin.