Why does an open MRI scan take so much longer than regular high-field MRI?

Examination times are longer than in regular MRI because the magnetic field strength is lower and therefore requires more time to acquire images for a quality exam.

Is the scanner a tube?

No , an open MRI scanner has a wide, non-constricting space.

Will the head being out of the scanner?

The area of the body being scanned will be in the center of the scanner for most procedures with the exception of the head, neck, or shoulder areas, your head will remain outside the scanner.

Is there any risk?

MRI is very safe. There are no health risks associated with the magnetic field or of the radio-waves used by the machine, nor have any side effects been reported. Patients with a pacemaker or certain types of aneurysm clips should not have MRI.