Test your knowledge of MRI angiography with Time of Flight and Phase Contrast te...

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Questions and Answers

What is necessary for multi-planar reconstruction in MRI?

3D data collection, isotropic voxels, and no gaps between slices (correct)

2D data collection, anisotropic voxels, and gaps between slices

2D data collection, isotropic voxels, and no gaps between slices

3D data collection, anisotropic voxels, and gaps between slices

What does MIP allow for visualization of in MRI?

High-intensity structures, such as contrast media (correct)

Low-intensity structures, such as bone

Soft tissue structures, such as muscle

All structures in the image

What is the role of gadolinium-based contrast agents in contrast-enhanced MRA?

To make tissues appear darker on the image

To make tissues appear brighter on the image (correct)

To make tissues appear more detailed on the image

To make tissues appear more blurry on the image

What is the purpose of the ADC map in diffusion-weighted imaging?

To help rule out artifact versus real pathology Signup and view all the answers

What is the purpose of saturation bands in TOF imaging?

To suppress certain types of flow in the image Signup and view all the answers

What is cine imaging used for in MRI?

Real-time imaging to see structures in motion Signup and view all the answers

What is the purpose of using inverse recovery sequences in MRI imaging?

To suppress tissue Signup and view all the answers

Which type of pulse sequence uses a 90-degree RF pulse and no 180-degree RF pulses?

Gradient echo sequences Signup and view all the answers

What is the importance of k space filling in contrast-enhanced MRA?

To optimize how data is collected to reduce motion and collect contrast data Signup and view all the answers

What can occur with 2D imaging in TOF?

Venetian-blind artifacts Signup and view all the answers

What is the purpose of suppression techniques in MRI?

To suppress certain tissues in the image Signup and view all the answers

What does k space represent in MRI images?

The frequencies and amplitudes of the patient's tissues Signup and view all the answers

What does the center of k space contain?

All the signal data Signup and view all the answers

What is the technique used to measure the velocities of tissue?

Phase contrast imaging Signup and view all the answers

What is the advantage of using spoiled gradient sequences in MRI imaging?

To obtain T1 contrast Signup and view all the answers

Where are high-frequency data found in k space?

In the outer regions Signup and view all the answers

What is the purpose of using steady-state free precession sequences in MRI imaging?

To promote a ratio of T2 to T1 contrast Signup and view all the answers

What is the purpose of radial filling in k space?

To compensate for motion in-plane Signup and view all the answers

How does fast spin echo reduce susceptibility in the image?

By using multiple 180-degree RF pulses to optimize the image Signup and view all the answers

Study Notes

MRI angiography exams can be achieved through different techniques, one of which is time of flight (TOF).
TOF works by exciting hydrogen in a volume and suppressing stationary tissues, so that only flowing tissues generate signals.
To optimize TOF, imaging must be done quickly, using a gradient aqua sequence and a short TE and TR.
TOF can be imaged using either a 2D or 3D technique, but the slices must be perpendicular to the direction of flow and acquired counter-currently.
3D imaging has the benefit of smoother images, but limitations in coverage due to the need for small slabs.
Saturation bands can be used to suppress or highlight certain types of flow in the image.
The direction of flow and positioning of the saturation bands depend on the location in the body being imaged.
Motion and Venetian-blind artifacts can occur with 2D imaging, but post-reconstruction options like MIT images are possible.
TOF is a unique MRA technique that generates images from signals received from flowing tissues.
The goal of TOF is to capture flowing protons before they exit the field of view or coil.
The technique being discussed is phase contrast imaging, which measures the velocities of tissue.
This technique is used to produce an image of flowing or moving protons.
A bipolar gradient is used to activate the technique, most likely in three directions.
The technique is sensitive to the velocity of tissue and can identify the flow of tissue in centimeters per second.
The strength of the gradient determines how sensitive the technique is to different types of flow.
Choosing the correct velocity encoding parameter is crucial to avoid aliasing of signal.
Advantages of the technique include suppression of stationary tissue and more information about the patient.
Disadvantages include the length of the technique, so it is not typically used for diagnostic images in the abdomen or chest.

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Description

Do you know about the MRI angiography technique known as Time of Flight (TOF)? This quiz will test your knowledge on the principles of TOF, including techniques, optimizing imaging, and the use of saturation bands. You'll also be quizzed on the unique phase contrast imaging technique, which measures the velocities of tissue and identifies the flow of tissue in centimeters per second. Test your understanding of these MRA techniques and their advantages and disadvantages with this informative quiz.