MRI MRI Anatomy and Positioning 2

Question 1

Which coil type provides the highest signal-to-noise ratio (SNR) for imaging small superficial structures such as the wrist?

Accepted Answer

Dedicated extremity or surface coil

Answer

Dedicated extremity or surface coils placed close to the anatomy maximize SNR by minimizing the receive volume to the region of interest.

Question 2

The 'magic angle' artifact in MRI tendons occurs at approximately what angle relative to the main magnetic field?

Accepted Answer

55°

Answer

Magic angle artifact occurs when a tendon is oriented at approximately 55° (the magic angle) to B0, causing artificial T1/PD signal increase that can mimic pathology.

Question 3

For pituitary gland MRI, which plane is considered the primary imaging plane?

Accepted Answer

Coronal

Answer

Coronal thin-slice images are the primary plane for pituitary imaging because they best demonstrate lateral extension, cavernous sinus invasion, and microadenomas.

Question 4

Which positioning aid is used to maintain the ankle in a 90° neutral position during MRI to optimally visualize the Achilles tendon?

Accepted Answer

Ankle positioning block or foam wedge

Answer

A foam wedge or ankle block holds the foot perpendicular to the leg, minimizing magic angle artifact and providing consistent Achilles tendon orientation.

Question 5

On a sagittal MRI of the cervical spine, the posterior longitudinal ligament appears as a thin structure along which surface of the vertebral bodies?

Accepted Answer

Posterior

Answer

The posterior longitudinal ligament runs along the posterior surfaces of the vertebral bodies inside the spinal canal, anterior to the thecal sac.

MRI - Magnetic Resonance Imaging Practice Test

MRI - Magnetic Resonance Imaging Practice Test

MRI MRI Anatomy and Positioning 2