The patient lies supine on an X-ray table with their body positioned symmetrically. For a pelvis X-ray, the cassette is centered between the pubic symphysis and iliac crests. The limbs may be rotated or padded as needed for clarity. Beam direction and collimation varies by area of interest but generally aims for the midline.

4. Position of patient and cassette
 The patient lies supine and symmetrical on the
X-ray table, with the median sagittal plane
perpendicular to the tabletop.
 The midline of the patient must coincide with
the centred primary beam and table Bucky
mechanism.
 If the patient remains on a trolley, ideally they
should be positioned down the midline and
adjusted to achieve an optimum projection
dependent on their degree of mobility.

5.  To avoid pelvic rotation, the anterior superior
iliac spines must be equidistant from the
tabletop.
 A non-opaque pad placed under a buttock can be
used to make the pelvis level.
 The coronal plane should now be parallel to the
tabletop.
 The limbs are slightly abducted and internally
rotated to bring the femoral necks parallel to the
cassette.
 Sandbags and pads are placed against the ankle
region to help maintain this position.

6.  Centre in the midline, with a vertical central
beam.
 The centre of the cassette is placed midway
between the upper border of the symphysis
pubis and anterior superior iliac spine for the
whole of the pelvis and proximal femora.
 The upper edge of the cassette should be 5
cm above the upper border of the iliac crest
to compensate for the divergent beam and to
ensure that the whole of the bony pelvis is
included.

8.  Positioning same as pelvic
Direction and centring of the X-ray beam
• The vertical central ray is directed 2.5 cm
distally along the perpendicular bisector of a
line joining the anterior superior iliac spine
and the symphysis pubis over the femoral
pulse.
• The primary beam should be collimated to
the area under examination and gonad
protection applied where appropriate.

10.  Position of patient and cassette
 The patient lies supine on the X-ray table,
with the legs extended. The median sagittal
plane coincides with the long axis of the table
Bucky.
 The patient rotates through 45 degrees on to
the affected side, with the hip abducted 45
degrees and flexed 45 degrees, and is
supported in this position by non-opaque
pads.

11.  The knee is flexed to bring the lateral aspect of
the thigh in contact with the tabletop. The knee
falls into a lateral position.
 The opposite limb is raised and supported
behind the limb being examined.
 A 24 30-cm cassette is used and placed
longitudinally and possibly obliquely in the Bucky
tray.
 The cassette is centred at the level of the femoral
pulse in the groin and should include the upper
third of the femur.
 The upper border of the cassette should be level
with the anterior superior iliac spine.

12.  Direction and centring of the X-ray beam
 Centre to the femoral pulse in the groin of
the affected side, with the central ray
perpendicular to the cassette.
 The long axis of the primary beam is adjusted
by turning the light beam diaphragm (LBD)
coincide with the long axis of the femur.
 The primary beam needs to be collimated to
the area under examination.

14.  Position of patient and cassette
 •The patient lies supine on the X-ray table, with the
anterior superior iliac spines equidistant from the
tabletop to avoid rotation of the pelvis.
 •The median sagittal plane is perpendicular to the
table and coincident with the centre of the table
Bucky mechanism.
 •The hips and knees are flexed and the limbs rotated
laterally through approximately 60 degrees.
 •The limbs are supported in this position by pads
and sandbags.
 •The cassette is centred at the level of the femoral
pulse to include both hip joints.

15. Direction and centring of the X-ray beam
•Centre in the midline at the level of the
femoral pulse, with the central ray
perpendicular to the cassette. Collimate to
thearea under examination.

17.  The patient lies supine on the X-ray table and is
positioned for a basic antero-posterior pelvic
projection.
 From this position, the patient is rotated
approximately 40 degrees on to the affected
side; the unaffected side is raised and
supported.
 Both hips and knees are flexed and the raised
limb is supported on a pad.
 The iliac fossa is now parallel to the cassette.

18. Centre midway between the anterior superior iliac spine of the
affected side and the midline of the pelvis, with the vertical
central ray perpendicular to the film.

19.  Position of patient and cassette
 The patient lies supine and symmetrical on the X-ray
table, with the median saggittal plane perpendicular.
 The midline of the patient must coincide with the
centred primary beam and the table Bucky
mechanism.
 To avoid rotation, the anterior superior iliac spines
must be equidistant from the tabletop.
 A 24 30-cm cassette, placed transversely in the
Bucky tray, is centred at a level to coincide with the
central ray.
 The shoulders are raised over a pillow to eliminate
the lumbar arch.
 The knees should be flexed over foam pads for
comfort.

20.  Centre in the midline at a level midway
between the anterior superior iliac spines and
the superior border of the symphysis pubis.
 • The central ray is directed between 5 and
15 degrees cranially, mdepending on the sex
of the patient. The female requires greater
caudal angulation of the beam.

22.  Thank You