Brain Imaging Quality Assurance: How to Acquire the Best Brain Images Possible

(A) Proper positioning in head holder. Canthomeatal line is imaginary line that runs from lateral corner of eye to ear canal. (B) Improper positioning. Canthomeatal line is not vertical and perpendicular to imaging table. (Reprinted from (8).)

(A) Proper positioning on imaging table using head strap, chin strap, and laser lights. Laser light denoted by yellow arrow is positioned at center of nose and forehead to prevent head rotation. Laser light denoted by red arrow, at level of ear, positions table height so that head is in middle of field of view. (Courtesy of Virtua Health, Voorhees, NJ.) (B) Knee cushion and body strap denoted by arrows. (Courtesy of Virtua Health, Voorhees, NJ.) (C) Challenge of positioning patients with kyphosis, severe neck pain, or severe back pain. Multiple pillows under legs, buttocks, and lower back help patient lie flat. Use of body straps to secure patient to table is important.

Key DaTscan positioning considerations. (A) Location of caudate nucleus and putamen within brain on MRI. Blue denotes right caudate, red denotes right putamen, and arrows denote left caudate and left putamen. (B) Transverse DaTscan image of caudate and putamen. (Courtesy of Holy Name Hospital, Teaneck, NJ.) (C) Effect of increasing camera radius on DaTscan image quality. As radius increases, quality decreases. Putamen looks shorter and less defined with 20-cm radius than with 12.8-cm radius. (Courtesy of Liz Clarke.) (D) Camera head must be as close as possible to nose for best image quality and must clear shoulders. (Courtesy of Holy Name Hospital, Teaneck, NJ.)

Effect of head orientation on DaTscan imaging. (A) Forward, backward, or sagittal head tilt has no effect on image quality. (Courtesy of Glasgow Southern Hospital.) (B) Lateral head tilt shows one putamen before the other, complicating interpretation. On amyloid imaging (right), yellow arrow denotes image on which left lateral lobe is first seen, and red arrow denotes image on which right lateral temporal lobe is first seen, almost 10 frames later. (Courtesy of Piramal Imaging.) (C) Head is tilted too far forward in sagittal slice at left and too far right in coronal slice. Although head position can be corrected during processing, best solution is to correctly position patient prior to image acquisition. Red line shows positioning that will result in properly oriented images after processing.

(A) Location of intercommissural line and AC–PC line. (B) MRI study showing improper and proper placement of processing lines. Forward head tilt results in slices (red lines) through caudate head that do not include putamen. On DaTscan studies, false-positive findings can result from incorrect positioning of processing lines. (Reprinted from (8).)