Principles of MRI of the Brain and Spine

Regarding the acquisition of MRI images:

Contrast changes on an MRI image:

Regarding contrast media and MRI:

Urgent MRI often has a role to play in spinal disorders, once assessment is complete. An 86-year-old woman is brought to the emergency department (ED), unable to cope at home. Neighbours say she is neglecting herself. Examination reveals weakness in both upper limbs, wasting of her hand muscles and reduced mobility in her neck. After examination you arrange an MRI scan of her neck (click on the scan to enlarge).

Which of the following statements are true? (Select all that apply)

A 58-year-old woman presents to the ED with immobility and loss of bladder function. She complains that her legs have been getting progressively weaker for some weeks and that she has trouble holding objects in her hands. She has hyperreflexia in all four limbs. You arrange an MRI scan of her neck (click on the scan to enlarge).

An ST6 doctor asks you for comments on the images. The scan shows:

Regarding the magnetic field in a MR scanning room:

In the initial management of stroke:

A 44-year-old man presents with lower back pain and sciatica. He has a history of a previous L5-S1 lumbar discectomy for cauda equina syndrome. His pain score is 9/10 and, after discussion with the orthopaedic team, you arrange an MRI scan (click on the scan to enlarge).

What abnormality is not present on this image?

A 37-year-old man presents to the ED with an 8-hour history of progressive weakness in his legs, associated with pain around his waist. He has not passed urine since the onset of symptoms. You note the presence of some healing cold sores around his mouth. After thorough clinical assessment an MRI scan is performed of the dorsal spine (click on the scan to enlarge).

Regarding the scan shown below: