Siemens SOMATOM Sensation 16, Application Manual, Page: 139 / 148

139
Extremities
Hints in General
• Topogram: AP, 128/256 mm for joint studies;
1024/1540 mm for CTA.
• Patient positioning:
Depends on the region of examination.
In general, for bilateral studies, you should always
try to position the patient evenly whenever the
patient can comply.
a) For wrists scan
Patient lying in prone position, hands stretched
above the head and lying flat on a Bocollo pillow,
ankles supported with a pad. Both wrists should
be examined together when necessary.
b) For knee scan:
Patient lying in supine position, feet first, pro-
mote relaxation by placing Bocollo pillows between
knees and feet, bind feet together.
The only exceptions are extremely light patients.
The latter can remove the leg not being examined
from the gantry by bending it 90° at the hip and
the knee and placing the bottom of the same foot
against the gantry casing.
c) For ankle and feet scan:
Patient lying in supine position, feet first.
Bind both ankles together if necessary to assure
the AP position of both feet.
Special positioning is not necessary since the real
time MPR could simulate any view of secondary
reconstruction.
d) UHR mode requires a 25 cm scan FOV as a
maximum. Use CombiSpi mode when a scan
FOV > 25 cm is necessary.
• In case of 3D study only, mAs can be reduced up
to 50%. Use kernel B10 and 50% overlapping image
reconstruction.