ICH Volume Calculator

The ICH volume calculator is an important tool to evaluate the size of parenchymal hemorrhage depending on a CT scan. This calculator mainly follows the formula of ABC2 (ABC CT) to evaluate the proper dimensions of parenchymal hemorrhage. The other important thing you need to know is the accurate dimensions of the bleed on the CT scan.

This article is all about the ICH volume calculator, ABC formula, and associated details of these abbreviations and formulas. In addition, it also provides details about the parenchymal hemorrhage and associated side effects. You can easily use this calculator to check the severity and mortality rate related to intracerebral or parenchymal hemorrhage.

What is the detailed form of the ABC CT formula?

ABC CT formula is a commonly used formula to assess the volume or size of a hemorrhage. CT scan is a short form of computed tomography scan. It is an imaging technique to provide the best results related to hemorrhage. The ABC formula is mentioned below:

ICH volume = A × B × C × slices / 2

In this formula, A denotes the maximum length of the bleed

B indicates perpendicular width to the A on the same head slice of the CT scan

C indicates the width of a single slice

Slices indicate the total number of slices exhibiting signs of hemorrhage

What is the ABC2 formula?

The ABC2 formula is the more advanced version of the ABC CT formula. The ABC2 formula is as follows:

ICH volume = A × B × C × slices / hemorrhage shape

Talking about hemorrhage shape, it can be round, elliptical, irregular, separated, or multinodular.

The volume of an ellipsoid or elliptical shape is equal to 4/3 × π × (A/2) × (B/2) × (C/2). In a rough estimation, π = 3, so the overall value becomes A × B × C / 2

What is parenchymal hemorrhage?

A parenchymal hemorrhage is a bleed that happens within the parenchyma of the brain. This bleeding point cam can cause disturbance in the normal oxygen supply to the blood cells. Decreased perfusion to the brain cells may cause brain cell death, leading to severe consequences. Primary hemorrhage occurs due to the sudden rupture of the damaged cranial arteries. Whereas, secondary parenchymal hemorrhage occurs due to the predisposition of the disease because of other medical conditions.

What are the common causes of parenchymal hemorrhage?

Parenchymal hemorrhage is also known as intracerebral hemorrhage or bleeding. There are multiple acute and chronic causes leading to parenchymal hemorrhage. The most common medical problem associated with parenchymal hemorrhage is high blood pressure. High blood pressure may cause rupture or damage to the walls of the arteries present in the skull. These damage points may cause bleeding in the skull. To avoid this condition, it is a more focused point to maintain your blood pressure at optimum levels(120/80 mmHg). Check your blood pressure regularly to maintain a proper check and balance over your blood pressure limits.

The second most common cause of parenchymal hemorrhage includes cerebral amyloid angiopathy. It is a medical condition associated with the deposition of amyloid plaque causing severe damage to the arteries in the skull. There are also different other causes associated with parenchymal hemorrhage. These are as follows:

  • Drugs that can affect the normal INR values also have an impact on the causes of parenchymal hemorrhage. These drugs include warfarin and heparin. These drugs are blood thinners and help to prevent clotting in heart and stroke conditions. Check your INR rate to avoid serious problems.
  • Arteriovenous malformations are also associated with ICH.
  • Aneurysm
  • Any head injury or trauma, fractures, penetrating wounds, or any roadside accident can cause parenchymal hemorrhage even if you do not see any visible open wound on the surface of the skull.
  • Bleeding disorders, including sickle cell anemia, hemophilia, thrombocytopenia, or DIC.
  • Tumors, including angiomas and metastatic tumors, may cause parenchymal hemorrhage because of their increased vascularization nature.
  • There may be sudden bleeding within the skull without any obvious reason, leading to parenchymal hemorrhage.

What is the ICH volume calculator?

The ICH volume calculator follows the typical ABC formula to provide you with the best results related to the volume of parenchymal hemorrhage. All you need is to extract important details from a head CT scan. Here is a way to go for the ICH volume calculator.

  • Measure the length, mentioned as A, and width (B) of the bleeding area visible on the CT scan.
  • In addition, count the number of slices on the CT scan, indicating the bleeding. Moreover, also measure the approximate width of every slice. If the bleeding area covers ≥75% of the slice, it indicates one slice. Moreover, if the slice coverage lies between 25 to 75%, you will count it as 0.5. If the area covered is less than 25%, it will not be counted. In advanced mode, the number of slices can automatically be calculated.
  • After this, select the type of hemorrhage shape. Every shape has a different volume formula. For a round or ellipsoid shape, the hemorrhage shape is replaced by 2 in the formula. For the irregular, separated, or multinodular shape, it is substituted by 3 in the formula. The formula for the ICH volume calculator is

ICH volume calculator = A × B × C  / hemorrhage shape

This formula provides the value of ICH in ml, mm³, or cm³.

An intracerebral hemorrhage volume of greater than 50 to 60 mL indicates a poor prognostic marker.

How to use an ICH volume calculator in clinical practice?

Let us take an example to understand the usage of this calculator. A 70-year-old Mahesh was admitted to the Department of Neurology because of restricted movement on the left side of the body after a roadside accident. The physician has a provisional diagnosis of stroke. The physician decided to go for a CT scan. On a CT scan, the physician finds a parenchymal hemorrhage. The physician wants to know the volume of parenchymal hemorrhage. These are the findings of the CT scan.

  • Length – 4cm
  • Width – 3.5 cm
  • The thickness of the CT scan slice – 2.5 mm
  • The total number of slices – 42 slices
  • Shape – round

Let us put all these values in the ICH volume calculator formula.

ICH volume = 4 × 3.5 × 0.2 × 42 / 2

ICH volume = 73.5 mL

This parenchymal hemorrhage volume indicates a poor prognosis.


The ICH volume calculator is a diagnostic tool for physicians to evaluate the accurate dimensions of the parenchymal hemorrhage. It is important to know the size of the parenchymal hemorrhage to avoid any severe consequences and to better management. This article is all about the associated formulas with the ICH volume calculator and other important details. Give it a read to get to know the basic concepts related to parenchymal hemorrhage.

Frequently asked questions (FAQs)

Is parenchymal hemorrhage a serious medical problem?

Parenchymal hemorrhage is a medical emergency that should be treated as soon as possible. Sudden parenchymal hemorrhage is only associated with stroke in 20% of cases. It is associated with higher mortality and morbidity rates.

Is it possible to recover from the parenchymal hemorrhage?

For the majority of cases, patients recover from the intracerebral hemorrhage within the starting few months if treated immediately. But, if not treated properly, it may lead to an increased mortality rate.

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