# What is B value in diffusion weighted imaging?

## What is B value in diffusion weighted imaging?

The b-value is a factor that reflects the strength and timing of the gradients used to generate diffusion-weighted images. The higher the b-value, the stronger the diffusion effects.

### What is the B value for DWI MRI?

Conclusion: In DWI, we recommend the use of b-values of 0 and 800 s/mm(2) as two b-values, or b=0, 50, 600, 800, and 1000 s/mm(2) as multiple b-values for distinguishing between benign and malignant liver lesions.

#### What does diffusion weighted imaging measure?

Diffusion-weighted imaging (DWI) is a form of MR imaging based upon measuring the random Brownian motion of water molecules within a voxel of tissue. In general simplified terms, highly cellular tissues or those with cellular swelling exhibit lower diffusion coefficients.

**How is ADC map calculated?**

Apparent diffusion coefficient (ADC) can also be calculated from multiple diffusion-weighted images easily by fitting the diffusion tensor to the signals. Traditionally, you would use one b=0 image and at least six diffusion-weighted images with the same b-value but different gradient directions.

**What are the B values?**

He listed the B-values as:

- Truth: honesty; reality; simplicity; richness; oughtness; beauty; pure, clean and unadulterated; completeness; essentiality.
- Goodness: rightness; desirability; oughtness; justice; benevolence; honesty.

## What is diffusion tensor imaging used for?

Diffusion tensor imaging (DTI) is a promising method for characterizing microstructural changes or differences with neuropathology and treatment. The diffusion tensor may be used to characterize the magnitude, the degree of anisotropy, and the orientation of directional diffusion.

### What is diffusion in the brain?

Diffusion in the extracellular space (ECS) of the brain is constrained by the volume fraction and the tortuosity and a modified diffusion equation represents the transport behavior of many molecules in the brain. Early diffusion measurements used radiolabeled sucrose and other tracers.

#### What is the b value of diffusion weighted sequences?

The b-value is a factor of diffusion weighted sequences. The b factor summarizes the influence of the gradients on the diffusion weighted images. The higher the value b, the stronger the diffusion weighting.

**What does the b value of a MRI mean?**

The b-value is a factor that reflects the strength and timing of the gradients used to generate diffusion-weighted images. The higher the b -value, the stronger the diffusion effects.

**Which is the best value for apparent diffusion coefficient?**

To sense slow moving water molecules and smaller diffusion distances, b values should be higher (e.g. b = 500 s/mm 2 ). Apparent diffusion coefficient is calculated using different b-values (e.g 0-1000 s/mm 2 ). A useful rule of thumb is to choose the b value such that (b X ADC) is nearly equal to 1. 1. Koh DM, Padhani AR.

## How are units of diffusion expressed in MRI?

In a prior Q&A we showed that because diffusion is the flux of particles across a surface in a period of time, the units of D are of the form [area/time]. So that exp (−bD) will be dimensionless, the units for b should be the inverse of D. In other words, b should be expressed as [time/area].