informative documents for radiology students.

2. Rotation of the lower limb
occurs at the hip joint. The position of the foot relates to the direction of
rotation.
•
the dorsal surface and slopes downwards, at a variable angle,
from the ankle to the toes and from medial to lateral.
•
plantar aspect.
•
the medial aspect.
•
body is the lateral aspect.
the anterior surface faces medially. This will produce internal
rotation of the hip joint.
•
the anterior surface faces laterally. This will produce external
rotation of the hip joint.
•
dorsal surface of the foot is moved in a superior direction.
•
the plantar surface of the foot is moved in an inferior direction.
•
of the foot is turned to face medially, with the limb extended.
the foot is turned to face laterally, with the limb extended.
joint relates to the angle between the axis of the tibia when the knee is
extended and the angle of the axis of the tibia
when the knee is flexed.

3. Eversion
Inversion
Plantarflexion
Dorsiflexion
Lateral rotationMedial rotation

4. Basic projections
• The patient is seated on the X-ray table,
supported if necessary, with the affected hip and
knee flexed.
• The plantar aspect of the affected foot is placed
on the cassette and the lower leg is supported in
the vertical position by the other knee.
• Alternatively, the cassette can be raised on a 15-
degrees foam pad for ease of positioning.
• The central ray is directed over the cuboid-
navicular joint, midway between the palpable
navicular tuberosity and the
tuberosity of the fifth metatarsal.
• The X-ray tube is angled 15 degrees cranially
when the cassette is flat on the table.
• The X-ray tube is vertical when the cassette is
raised on a 15-degree pad.
Normal dorsi-plantar radiograph of foot

5. This projection allows the alignment of the
metatarsals with the distal row of the tarsus to
be assessed.
• From the basic dorsi-plantar position, the
affected limb is allowed to lean medially to
bring the plantar surface of the foot
approximately 30–45 degrees to the cassette.
• A non-opaque angled pad is placed under the
foot to maintain the position, with the opposite
limb acting as a support.
• The vertical central ray is directed over the
cuboid-navicular joint.
Normaldorsi-plantar
obliqueradiographoffoot

6. • From the dorsi-plantar position, the leg is
rotated outwards to bring the lateral aspect
of the foot in contact with the cassette.
• A pad is placed under the knee for support.
• The position of the foot is adjusted slightly
to bring the plantar aspect perpendicular to
the cassette.
• The vertical central ray is centred over the
navicular cuneiform joint.
Normal lateral radiograph of foot
• The patient stands on a low platform with a
cassette placed vertically between the feet.
• The feet are brought close together The weight
of the patient’s body is distributed equally.
• To help maintain the position, the patient
should rest their forearms on a convenient
vertical support, e.g. the vertical Bucky.
• The horizontal central ray is directed towards
the tubercle of the fifth metatarsal.

7. Dorsi-plantar erect projection
of both feet showing hallux valgus

8. Position of patient and cassette
• The patient is seated on the X-ray table, supported
if necessary, with hips and knees flexed.
• The plantar aspect of the affected foot is placed on
the cassette This cassette may be supported on a 15-
degree pad.
• The leg may be supported in the vertical position
by the other knee.
• The vertical central ray is directed over the third
metatarsophalangeal joint, perpendicular to the
cassette if all the toes are to be imaged.
• For single toes, the vertical ray is centred over the
metatarsophalangeal joint of the individual toe and
collimated to include the toe either side.
Normal dorsi-plantar projection of all toes

9. • From the basic dorsi-plantar position, the affected
limb is allowed to lean medially to bring the plantar
surface of the foot approximately 45 degrees to the
cassette.
• A 45-degree non-opaque pad is placed under the
side of the foot for support, with the opposite leg
acting as a support.
The vertical ray is centred over the first metatarso-
phalangeal joint if all the toes are to be imaged and
angled sufficiently to allow the central ray to pass
through the third metatarsophalangeal joint.
• For single toes, the vertical ray is centred over the
metatarsophalangeal joint of the individual toe,
perpendicular to the cassette.

10. • From the dorsi-plantar position, the foot is rotated medially
until the medial aspect of the hallux is in contact with the
cassette. A bandage is placed around the remaining toe
(provided that no injury is suspected) and they are gently
pulled forwards by the patient to clear the hallux.
Alternatively, they may be pulled backwards; this shows the
metatarsophalangeal joint more clearly.
• The vertical ray is centred over the first metatarso-
phalangeal joint.
The patient lies on the unaffected side, and the medial aspect of
the affected leg and foot is placed in contact with the table.
• The cassette is placed under the foot to include the phalanges of
the hallux and the distal part of the first metatarsal.
• The hallux is then dorsiflexed with the aid of a bandage and held
by the patient.
• Centre with the vertical ray perpendicular to the cassette,
over the first metatarso-phalangeal joint.

11. There is a choice of two positions for this projection:
1 The patient is positioned as for the lateral
projection of the
foot. The foot is raised on a support and the cassette is
supported vertically and well into the instep. A
horizontal beam is used in this case.
2 The patient sits on the X-ray table, with legs
extended. The
hallux is then dorsiflexed with the aid of a bandage
and held by the patient. The cassette is raised on a
support and positioned firmly against the instep.
• Centre to the sesamoid bones with the central ray
projected tangentially to the first metatarso-
phalangeal joint.

12. (Mortice projection)
•The patient is either supine or seated on the
X-ray table with both legs extended.
•A pad may be placed under the knee for
comfort.
•The affected ankle is supported in
dorsiflexion by a firm 90-degree pad placed
against the plantar aspect of the foot.
The limb is rotated medially (approximately
20 degrees) until the medial and lateral
malleoli are equidistant from the cassette.
•The lower edge of the cassette is positioned
just below the plantar aspect of the heel.
Centre midway between the malleoli with
the vertical central ray at 90 degrees to an
imaginary line joining the malleoli.

13. 15-degree pad is placed under the lateral
border of the
forefoot and a pad is placed under the knee
for support. The
lower edge of the cassette is positioned just
below the plantar
aspect of the heel.
• Centre over the medial malleolus, with the
central ray at
right-angles to the axis of the tibia.

14. • From the sitting position, whilst the patient is in
a wheelchair, the whole limb is raised and
supported on a stool and a pad is placed under the
raised knee for support.
• The lower limb is rotated medially, approximately
20 degrees, until the medial and lateral malleoli
are equidistant from the cassette. A non-opaque
angled pad is placed against the medial border of
the foot and sandbags are placed at each side of
the leg for support.
• The lower edge of the cassette is placed just below
the plantar aspect of the heel.
• Centre midway between the malleoli, with the
vertical central ray at 90 degrees to the imaginary
line joining the malleoli or compensatory
angulation of the beam if the foot is straight

15. –
• With the patient maintaining the sitting
position or lying on the trauma trolley, the
limb is raised and supported on a firm non-
opaque pad.
• A cassette is placed against the medial
aspect of the limb. The lower edge of the
cassette is placed just below the plantar
aspect of the heel.
• The horizontal central ray is directed to the
lateral malleolus.

16. • The patient and cassette are positioned for the
routine antero-posterior projection.
• The doctor in charge forcibly inverts the foot
without internally rotating the leg.
• Centre midway between the malleolus, with the
central ray at right-angles to the imaginary line
joining the malleoli.
• The patient lies supine on the table, with the limb
extended.
• The foot is elevated and supported on a firm pad.
• The ankle is dorsiflexed and the limb rotated
medially until the malleoli are equidistant from the
tabletop.
• The film is supported vertically against the medial
aspect of the foot.
• The doctor applies firm downward pressure on
the lower leg.
• Centre to the lateral malleoli with a horizontal beam.

17. • From the supine position, the patient
rotates on to the affected side.
• The leg is rotated until the medial and
lateral malleoli are superimposed vertically.
• A 15-degree pad is placed under the
anterior aspect of the knee and the lateral
border of the forefoot for support.
• The cassette is placed with the lower edge
just below the plantar aspect of the heel.
• Centre 2.5 cm distal to the medial
malleolus, with the vertical central ray
perpendicular to the cassette.
Normal lateral radiograph of calcaneum

18. Normal axial projection of calcaneum
• The patient sits or lies supine on the X-ray,
table with bot limbs extended.
• The affected leg is rotated medially until
both malleoli ar equidistant from the film.
• The ankle is dorsiflexed The position is
maintained by usin a bandage strapped
around the forefoot and held in position by
the patient.
• The cassette is positioned with its lower
edge just distal to the plantar aspect of the
heel.
• Centre to the plantar aspect of the heel at
the level of the tubercle of the fifth
metatarsal.
• The central ray is directed cranially at an
angle of 40 degrees to the plantar aspect of
the heel.

19. • The patient lies supine on the X-ray table,
with the affected limb extended.
• The ankle joint is dorsiflexed and the
malleoli are equidistant from the film.
• The leg is internally rotated through 45 dgr
• A pad is placed under the knee for support.
• A non-opaque square pad and sandbag
may be placed against the plantar aspect of
the foot to keep the ankle joint in
dorsiflexion.
• The lower edge of the cassette is placed at
the level of the plantar aspect of the heel.
Centre 2.5 cm distal to the lateral malleolus
with the following cranial angulations:

20. • The patient lies supine on the X-ray table,
with the affected limb extended.
• The ankle joint is dorsiflexed and the
malleoli are equidistant from the cassette.
• The leg is externally rotated through 45 d
• A pad is placed under the knee for support.
• A non-opaque square pad and sandbag
may be placed against the plantar aspect of
the foot to keep the ankle joint in
dorsiflexion.
• The lower edge of the cassette is placed at
the level of the plantar aspect of the heel.
Centre 2.5 cm distal to the medial
malleolus, with the central ray angled 15
degrees cranially.

21. • The patient lies on the affected side.
• The opposite limb is flexed and brought in
front of the affected limb.
• The affected foot and leg are now further
rotated laterally until the plantar aspect of
the foot is approximately 45 degrees to the
cassette.
• The lower edge of the cassette is positioned
just below the plantar aspect of the heel.
• Centre to the medial malleolus, with the
central ray angled 20 degrees caudally.
Radiograph of subtalar joints – lateral oblique projection

22. • The patient is either supine or seated on the X-ray table, with both
legs extended • The ankle is supported in dorsiflexion by a firm 90-
degree pad placed against the plantar aspect of the foot. The limb is
rotated medially until the medial and lateral malleoli are equidistant
from the cassette. • The lower edge of the cassette is positioned just
below the plantar aspect of the heel.
Centre to the middle of the cassette, with the central ray at right-
angles to both the long axis of the tibia and an imaginary line joining
the malleoli.
• From
the supine/seated position, the patient rotates on to the affected
side. • The leg is rotated further until the malleoli are superimposed
vertically. • The tibia should be parallel to the cassette.
• A pad is placed under the knee for support. • The lower edge of the
cassette is positioned just below the plantar aspect of the heel.
• Centre to the middle of the cassette, with the central ray at right-
angles to the long axis of the tibia and parallel to an imaginary line
joining the malleoli.

23. Antero-posterior
Latera

24. The patient lies on the affected side, with the knee
slightly flexed. • The other limb is brought forward in
front of the one being examined and supported on a
sandbag. • The head of the fibula and the lateral tibial
condyle of the affected side are palpated and the limb
rotated laterally to project the joint clear of the tibial
condyle. • The centre of the cassette is positioned at the
level of the head of the fibula.
• The vertical central ray is directed to the head of the
fibula.
• The patient is either supine or seated on the X-ray table,
with both legs extended. • Palpate the head of fibula and
the lateral tibial condyle. • Rotate the limb medially to
project the tibial condyle clear of the joint. • The limb is
supported by pads and sandbags. • The centre of the
cassette is positioned at the level of the head of the fibula.
The vertical central ray is directed to the head of the
fibula.

25. • The patient is either supine or seated on
the X-ray table, with both legs extended.
The affected limb is rotated to centralize
the patella between the femoral condyles,
and sandbags are placed against the ankle to
help maintain this position.
• The cassette should be in close contact
with the posterior aspect of the knee joint,
with its centre level with the upper borders
of the tibial condyles.
Centre 2.5 cm below the apex of the patella
through the joint space, with the central ray
at 90 degrees to the long axis of the tibia.
Normal antero-posterior radiograph

26. • The patient lies on the side to be examined,
with the knee flexed at 45 or 90 degrees (see
below).
• The other limb is brought forward in front
of the one being examined and supported
on a sandbag.
• A sandbag is placed under the ankle of the
affected side to bring the long axis of the
tibia parallel to the cassette.
• The position of the limb is now adjusted to
ensure that the femoral condyles are
superimposed vertically.
• The centre of the cassette is placed level
with the medial tibial condyle.
• Centre to the middle of the superior border
of the medial tibial condyle, with the central
ray at 90 degrees to the long axis of the tibia.
Lateral radiograph of the knee with
90 degrees of flexion

27. This projection replaces the conventional
lateral in all cases of gross injury and
suspected fracture of the patella.
• The patient remains on the trolley/bed,
with the limb gently raised and supported
on pads.
• If possible, the leg may be rotated slightly
to centralize the patella between the femoral
condyles.
• The film is supported vertically against th
medial aspect of the knee.
• The centre of the cassette is level with the
upper border of the tibial condyle.
• The horizontal central ray is directed to the
upper border of the lateral tibial condyle, at
90 degrees to the long axis of the tibia.
Horizontal beam lateral

28. • The cassette is supported in the chest
stand.
• The patient stands with their back against
the vertical Bucky, using it for support if
necessary.
• The patient’s weight is distributed equally.
• The knee is rotated so that the patella lies
equally between the femoral condyles.
• The limb is rotated slightly medially to
compensate for th obliquity of the beam
when the central ray is centred midway
between the knees.
• The centre of the cassette is level with the
palpable upper borders of the tibial
condyles.
The horizontal beam is centred midway
between the palpabl upper borders of the
tibial condyles.

29. • The patient and cassette are positioned for
the routine anteroposterior
projection.
• The doctor forcibly abducts or adducts the
knee, without
rotating the leg.
• Centre midway between the upper borders
of the tibial
condyles, with the central ray at 90 degrees
to the long axis
of the tibia.
Antero-posterior knee with varus
stress
Antero-posterior knee with valgus
stress

30. • The patient lies prone on the table, with
the knee slightly flexed.
• Foam pads are placed under the ankle and
thigh for support.
• The limb is rotated to centralize the
patella.
• The centre of the cassette is level with the
crease of the knee.
• Centre midway between the upper borders
of the tibial condyles at the level of the
crease of the knee, with the central ray at 90
degrees to the long axis of the tibia. Postero-anterior radiograph of normal patella

31. The patient sits on the X-ray table, with the
knee flexed 30–45 degrees and supported on
a pad placed below the knee.
• A cassette is held by the patient against the
anterior distal femur and supported using a
non-opaque pad, which rests on the anterior
aspect of the thigh.
• The tube is lowered. Avoiding the feet, the
central ray is directed cranially to pass
through the apex of the patell parallel to the
long axis.
• The beam should be closely collimated to
the patella and femoral condyles to limit
scattered radiation to the trunk and head.
Conventional infero-superior projection

32. • The patient sits on the X-ray table, with the
affected knee flexed over the side.
• Ideally, the leg should be flexed to 45
degrees to reflect a similar knee position to
the conventional skyline projection. Too
much flexion reduces the retro-patellar
spacing. Sitting th patient on a cushion
helps to achieve the optimum position.
• The cassette is supported horizontally on a
stool at the level of the inferior tibial
tuberosity border.
• The vertical beam is directed to the
posterior aspect of the proximal border of
the patella. The central ray should b parallel
to the long axis of the patella.
• The beam is collimated to the patella and
femoral condyles.
Supero-inferior image

33. • The patient lies prone on the X-ray table,
with the cassette placed under the knee
joint and the knee flexed through 90 dgri
• A bandage placed around the ankle and
either tethered to a vertical support or held
by the patient may prevent unnecessary
movement.
Centre behind the patella, with the vertical
central ray angled approximately 15 degrees
towards the knee, avoiding the toes
Normal infero-superior radiograph of patella, patient prone

34. • The patient lies prone on the X-ray table.
• The trunk is then rotated on to each side in turn to
bring either the medial or the lateral aspect of the
knee at an angle of approximately 45 degrees to the
cassette. • The knee is then flexed slightly.
• A sandbag is placed under the ankle for support.
• The centre of the cassette is level with the
uppermost tibial condyle.
• The vertical central ray is directed to the
uppermost tibial condyle.
• The
patient lies supine on the X-ray table. • The trunk is
then rotated to allow rotation of th affecte limb
either medially or laterally through 45 degrees. • The
knee is flexed slightly. • A sandbag is placed under
the ankle for support. • The centre of the cassette is
level with the upper border of the uppermost tibial
condyle.
• The vertical central ray is directed to the middle of
the uppermos tibial condyle.

35. • The patient is either supine or seated on
the X-ray table, with the affected knee flexed
to approximately 60 degrees.
• A suitable pad is placed under the knee to
help maintain the position.
• The limb is rotated to centralize the patella
over the femur.
• The cassette is placed on top of the pad as
close as possible to the posterior aspect of
the knee and displaced towards the femur.
• Centre immediately below the apex of the
patella, with the following angulations to
demonstrate either the anterior or posterior
aspects of the notch:
Radiograph of intercondylar notch

36. • The patient lies supine on the X-ray table,
with both legs extended.
• The affected limb is rotated to centralize
the patella over the femur.
• Sandbags are placed below the knee to help
maintain the position.
• The cassette is positioned in the Bucky tray
immediately under the limb, adjacent to the
posterior aspect of the thigh to include both
the hip and the knee joints.
• Alternatively, the cassette is positioned
directly under the limb, against the posterior
aspect of the thigh to include the knee joint.
• Centre to the middle of the cassette, with
the vertical central ray at 90 degrees to an
imaginary line joining both femoral
condyles.
Antero-posterior radiograph of
normal femur, knee up

37. • From the antero-posterior position, the
patient rotates on to the affected side, and
the knee is slightly flexed.
• The pelvis is rotated backwards to separate
the thighs.
• The position of the limb is then adjusted to
vertically superimposethe femoral condyles.
• Pads are used to support the opposite lim
behind the one being examined.
• The cassette is positioned in the Bucky tray
under the lateral aspect of the thigh to
include the knee joint and as much of the
femur as possible.
• Alternatively, the cassette is positioned
directly under the limb, against the lateral
aspect of the thigh, to include the knee
joint.
• Centre to the middle of the cassette, with
the vertical central ray parallel to the
imaginary line joining the femoral condyles.

38. • The patient remains on the trolley/bed. If
possible, the leg may be slightly rotated to
centralize the patella between the femoral
condyles.
• The cassette is supported vertically against
the lateral aspect of the thigh, with the lower
border of the cassette level with the upper
border of the tibial condyle.
• The unaffected limb is raised above the
injured limb, with the knee flexed and the
lower leg supported on a stool or specialized
support.
• Centre to the middle of the cassette, with
the beam horizontal.

39. The patient stands on a low step, with the posterio aspect of the
legs against the long cassette. The arms are folded across the
chest. The anterior superior iliac spines should be equidistant
from the cassette. The medial sagittal plane should be vertical and
coincident with the central longitudinal axis of the cassette. • The
legs should be, as far as possible, in a similar relationship to the
pelvis, with the feet separated s that the distance between the
ankl joints is similar to the distance between the hip joints and
with the patella of each knee facing forward. • Ideally, the knees
and ankle joints should be in the anteroposterior position.
However, if this impossible to achieve, it is more important that
the knees rather than the ankle joints are placed in the antero-
posterior position. • Foam pads and sandbags are used to stabilize
the legs and maintain the position. If necessary, a block may be
positioned below a shortened leg to ensure that there is no pelvic
tilt and that the limbs are aligned adequately.
• The horizontal central ray is
directed towards a point midway between the knee joints. • The
X-ray beam is collimated to include both lower limb from hip
joints to ankle joints.