IMPCB - Magnetic Resonance Imaging

How can this MRI artifact reduced?

• Calibrate shimming coil performance

• K-space post processing

• Apply a low pass filter prior to ADC

• Improve patient immobilization

In MRI imaging, T1 relaxation refers to:

• The time required for transverse relaxation to decay to 37% of it's maximum value.

• The time required for transverse relaxation to recover to 67% of it's maximum value.

• The time required for the longitudinal magnetization to regrow to 67% of it's equilibrium

  value.

• The time required for the longitudinal magnetization to decay to 37% of it's equilibrium value.

What pulse sequence may be used to reduce motion artifact?

• FLAIR

• PROPELLER acquisition

• T1 weighted acquisition

• Proton weighted acquisition

What MRI imaging sequence would be most appropriate in reducing the intensity of CSF

(Cerebrospinal fluid) in a brain scan?

• FLAIR

• T2

• STIR

• T2 Propeller

What is the likely cause of the below artifact?

• Too rapid TE caused signal loss at resonance frequencies

• The frequency encode magnets have lost uniformity

• A ferromagnetic object was left on the patient

• Insufficient RF shielding

What is the function of gradient coils in an MRI?

• Stimulate hydrogen procession

• Selectively spoil hydrogen excitation to tailor contrast

• Localize plane to be imaged

• Improve field homogeneity

What type of weighting was used in the below MRI image?

• TE weighting

• T1 weighting

• T2 weighting

• TR weighting

A radiologist is having trouble differentiating brain edema from the surrounding CSF. What MRI

protocol would you suggest to improve differentiation?

• Diffusion weighted

• T1 with gadolinium contrast

• T2 with gadolinium contrast

• FLAIR

What is the procession frequency of hydrogen in a 3T magnetic field?

• 512MHz

• 1024MHz

• 128MHz

• 64MHz

What MRI protocol is most likely to be used to identify areas of edema?

• FLAIR

• T1 weighted

• Apparent Diffusion Coefficient

• Proton density weighted