Quick Answer: What Is HU Value?

What is Hu in kidney stones?

Hounsfield Units (HU) indicate the hardness of renal calculi and identify high density stones to be excluded from shockwave lithotripsy (SWL) [2].

Several in vitro studies have demonstrated the utility of CT in predicting stone composition [3,4,5,6]..

How is Hu calculated?

The complete formula is given as: HU = 1000x ((μX – μwater) / μwater)…What is the Hounsfield unit.SubstanceHUCancellous Bone+700Dense Bone+30008 more rows•Dec 8, 2014

What is the principle of CT?

CT uses ionizing radiation, or x-rays, coupled with an electronic detector array to record a pattern of densities and create an image of a “slice” or “cut” of tissue. The x-ray beam rotates around the object within the scanner such that multiple x-ray projections pass through the object (Fig 1).

What is the hardest type of kidney stone?

The calcium oxalate kidney stone comes in two varieties, calcium oxalate monohydrate and calcium oxalate dihydrate. The former are harder and therefore more resistant to fragmentation by lithotripsy.

Who invented CT scan?

Godfrey HounsfieldGodfrey Hounsfield, a biomedical engineer contributed enormously towards the diagnosis of neurological and other disorders by virtue of his invention of the computed axial tomography scan for which he was awarded the Nobel Prize in 1979.

What are different densities on CT?

Tissues like air and water have little attenuation and are displayed as low densities (dark), whereas bone has high attenuation and is displayed as high density (bright) on CT. Among pathologic conditions, high density lesions are often seen with freshly clotted blood, hyperemia and with the use of contrast.

What is Hounsfield number in CT scan?

After image reconstruction, each pixel in the CT image is assigned a number, referred to as the Hounsfield or CT number, which is a rescaled normalized function of the linear attenuation coefficient [1, 2].

What is the Hu for blood?

45 to 65HUHounsfield units – scale of HU, CT numbersMatterDensity (HU)Blood45 to 65HULiver45 to 65HUHematoma40 to 90HUBone700 to 30008 more rows•Nov 15, 2013

What color is blood on CT scan?

whiteLook for any evidence of bleeding throughout all slices of the head CT. Blood will appear bright white and is typically in the range of 50-100 Houndsfield units. Basic categories of blood in the brain are epidural, subdural, intraparenchymal/intracerebral, intraventricular, and subarachnoid.

What are the worst foods for kidney stones?

Avoid stone-forming foods: Beets, chocolate, spinach, rhubarb, tea, and most nuts are rich in oxalate, which can contribute to kidney stones. If you suffer from stones, your doctor may advise you to avoid these foods or to consume them in smaller amounts.

Is 2 cm a big kidney stone?

This treatment is usually considered for larger kidney stones (2 cm or more), complex stones, or lower pole renal stones larger than 1 cm. Possible complications may include bleeding, infection, and injury to surrounding organs.

What is the Hu of water?

Hounsfield units are obtained from a linear transformation of the measured attenuation coefficients 1. This transformation (figure 1) is based on the arbitrarily-assigned densities of air and pure water: radiodensity of distilled water at standard temperature and pressure (STP) = 0 HU.