Prothrombin Time: Definition, Uses, and Clinical Overview

Prothrombin Time is a blood test that measures how quickly plasma forms a clot. It reflects the function of specific clotting proteins made largely by the liver. It is commonly reported in seconds and often standardized as the international normalized ratio (INR). It is widely used in hepatology, peri-procedural care, and anticoagulation monitoring.

Total Protein: Definition, Uses, and Clinical Overview

Total Protein is a blood (or body fluid) measurement of the combined amount of protein present. In serum, it mainly reflects albumin plus a broad group called globulins. It is commonly reported on routine chemistry panels and in evaluations of liver disease, nutrition, and inflammation. In gastroenterology and hepatology, it is often interpreted alongside albumin, liver enzymes, and bilirubin.

GGT: Definition, Uses, and Clinical Overview

Gamma-glutamyl transferase (GGT) is an enzyme measured in blood. It is most commonly used as part of a liver and biliary (hepatobiliary) evaluation. Clinicians use GGT to help interpret abnormal liver-related lab patterns, especially when alkaline phosphatase is elevated. It is discussed frequently in gastroenterology, hepatology, and general internal medicine.

ALP: Definition, Uses, and Clinical Overview

Alkaline phosphatase (ALP) is an enzyme measured on routine blood tests. It is found in several tissues, especially the liver and bile ducts and also bone. Clinicians use ALP most often to evaluate cholestasis, meaning reduced or blocked bile flow. ALP is commonly interpreted alongside other liver blood tests in gastroenterology and hepatology.

AST: Definition, Uses, and Clinical Overview

Aspartate aminotransferase (AST) is a blood test commonly used in liver and gastrointestinal (GI) medicine. AST is an enzyme found inside liver cells and several other tissues, including muscle. When cells are injured, AST can leak into the bloodstream and become measurable. Clinicians most often interpret AST alongside other “liver enzymes” and liver function tests.

ALT: Definition, Uses, and Clinical Overview

ALT is a blood test marker most commonly used to assess liver cell injury. ALT stands for alanine aminotransferase, an enzyme found mainly in liver tissue. Clinicians often order ALT as part of “liver enzymes” or a hepatic function panel. ALT is used in gastroenterology and hepatology to help interpret symptoms, risk factors, and other test results.

Liver Function Test: Definition, Uses, and Clinical Overview

A Liver Function Test is a group of blood tests used to assess liver-related enzymes, bilirubin handling, and protein synthesis. It is commonly ordered in primary care, emergency medicine, surgery, and gastroenterology/hepatology. It helps clinicians screen for hepatobiliary disease and monitor known liver conditions. Despite the name, many components reflect liver injury or bile flow rather than “function” alone.

Fibroscan: Definition, Uses, and Clinical Overview

Fibroscan is a noninvasive test that estimates liver stiffness using ultrasound-based elastography. It is commonly used in gastroenterology and hepatology clinics to assess liver fibrosis (scarring). Many systems can also estimate liver fat (steatosis) as part of the same exam. It is often used to help risk-stratify chronic liver disease without a liver biopsy.

MRCP: Definition, Uses, and Clinical Overview

Magnetic resonance cholangiopancreatography (MRCP) is a type of magnetic resonance imaging (MRI) focused on the bile ducts and pancreatic duct. It creates detailed pictures without using an endoscope or duct cannulation. MRCP is commonly used in gastroenterology, hepatology, and GI surgery to evaluate biliary and pancreatic duct problems. It is typically performed in a radiology department as part of an abdominal MRI exam.