Gradient echo sequences (GRE) are an alternative technique to spin-echo sequences, differing from it in two principal points: utilization of gradient fields to generate transverse magnetization. flip angles of less than 90°

Clinical magnetic resonance imaging (MRI) measures the spatial distribution of protons in the body. Gradient coils are used to provide spatial information. The changing gradients are associated with noise produced during imaging.

Slew rate refers to the speed at which a gradient can be turned on and off, and is defined as the maximum gradient strength of the gradient divided by the rise time. MR imaging is a product of magnetic field gradients which are created by magnetic gradient coils.

Duty cycle is the time during which the gradient system can be run at maximum power. The duty cycle is based on the total time and includes the cool down phase. The duty cycle on the RF pulse during MRI is restricted based on the specific absorption rate (SAR) limit. SAR limits restrict radio frequency heating effects.

Types of Gradients

• Linear. When you think of the word gradient, this is likely the concept that comes to mind.
• Radial. In a radial gradient, the colors fan out from the starting point in a circular pattern.
• Angle. An angle gradient sweeps counterclockwise around the starting point.
• Reflected. It’s all in the name.
• Diamond.

A linear gradient is horizontal, i.e the gradient colors appears as one on top of the other but for the radial, it takes a shape of either an oval or circle. A linear gradient progress in linear way,whereas radial gradient propagate either in a circle or ecliptic way.

A gradient fill is a graphical effect that produces a three-dimensional color look by blending one color into another. Multiple colors can be used, where one color gradually fades and changes to the other color, such as the gradient blue into white shown below.

How to work out the gradient of a straight line

1. In mathematics, the gradient is the measure of the steepness of a straight line.
2. A gradient can be uphill in direction (from left to right) or downhill in direction (from right to left).
3. Gradients can be positive or negative and do not need to be a whole number.

The Gradient tool creates a gradual blend between multiple colors. You can choose from preset gradient fills or create your own. Note: You cannot use the Gradient tool with bitmap or indexed-color images.

rate of change

Gradient, in mathematics, a differential operator applied to a three-dimensional vector-valued function to yield a vector whose three components are the partial derivatives of the function with respect to its three variables. The symbol for gradient is ∇.

A pressure gradient is the rate of change (gradient) of atmospheric (barometric) pressure with regard to horizontal distance at a given point in time. The value is usually expressed in mb per 100 mi. A large (steep) gradient produces strong winds. Weaker winds are found in areas with gentle pressure gradients.

Photoshop allows you to make a gradual transition between two or more colors by using the Gradient Tool. A gradient can be applied to any selected area of an image or background. If no area is selected, the gradient will be applied to the entire layer.

There are two different kinds of gradients in Lens Effects, Radial and Circular. Between the two types, you can achieve almost limitless effects.

using the Gradient Tool, click and drag the gradient in the direction you’d like to apply the blend. Note that the transparent side of the gradient will be the fade while the black side of the gradient will be the solid image. The longer the gradient, the more gradual the blend.

To use the gradient tool go to the Options bar and click on the gradient ramp (see Figure 1) to select a gradient option such as Foreground to Background color, or click on the small arrow to the right to open the gradient list (see Figure 2).

Click the shape, and when the Format tab appears, click Shape Fill. Click Gradient > More Gradients > Gradient fill. Pick a Type from the list. To set the direction for the gradient, click Direction.

How to Use the Gradient Tool in Adobe Illustrator

1. In this example, a spherical bubble will be created.
2. Go to the Gradient Panel [
3. The Gradient Panel has several moving parts.
4. To change the colors, double-click each of the Color Stops .
5. Gradients can be made up of as many colors as you wish.
6. The circle would look more spherical if the highlight was off-center.

Each new gradient must be created as two objects—the starting and ending color object—and blended individually. A gradient mesh, on the other hand, is a single object inside of which different color areas transition into one another with the effect of a blended object.

A new feature in the latest version of Adobe Illustrator CC, Freeform Gradient, makes it easy to create complex, multicolored gradients to transform your illustrations. To apply gradients with points, select Points in the Gradient panel, and then double-click a color stop to open the color swatch and apply a new color.

Apply a freeform gradient

1. Select the Gradient tool in the toolbar on the left and click in the artwork to apply a default White, Black gradient, in this instance.
2. In the Properties panel, click the Freeform Gradient button to change the gradient to a freeform gradient.

Just click POINT or LINE in the gradient panel to switch between them. When finished, switch to another tool to set the gradient. To edit the gradient later, select the shape then either switch to the Gradient tool or click EDIT GRADIENT in the Gradient panel.

To create a smooth looking Gradient or Blend in Illustrator look to these steps. If you are using the Blend Tool and you are getting banding, double-click on the Blend Tool in the Tool Palette. This should bring up a dialog box, make sure the pull-down menu is set to Smooth Color.