Chart For Positioning & Collimation - Key Notes

Arlo Guthrie — Tue, 21 Apr 2009 07:38:18 GMT

Current Revision posted to Revision Guide For Student Nurses - Part 2 by Arlo Guthrie on 4/21/2009 7:38:18 AM

Anatomy	Positioning	Aids	Collimation	Notes
Lateral Skull	Lateral recumbency	Foam wedges beneath muzzle to ensure that head is parallel to table; pad neck & sternum to stabilise.	Collimation depends upon the point of interest; possible areas include: cranium, zygomatic arch, mandibles, frontal sinuses, nasal turbinates, tympanic bullae & teeth.	The centering point depends upon the area of interest; the head may be tilted upwards for an improved view of the temporo-mandibular joints.
DV. Skull	Ventral recumbency	Muzzle positioned flat to the cassette; a sandbag over the neck secures the head in place.	Midline structures; ie. the frontal bone, frontal sinuses or maxillae.	Raising the cassette on a wooden block may aid positioning.
VD. Skull	Dorsal recumbency	Use trough to support VD position; foam pads will support the nose and neck, while tapes secured behind the upper canines hold the muzzle close to the plate.	Mandibles and tympanic bullae.	The head and neck must be extended; an open-mouthed oblique view variation on this position is suitable for radiographs of the nasal sinuses.
Oblique Skull	Lateral recumbency	The head is positioned within a trough to enable the skull to be angled correctly.	Tympanic bullae and temporo-mandibular joints.	The skull should be rotated 20 degrees around its long axis towards the VD position.
R.Ca. Skull (Rostro-caudal)	Dorsal recumbency (with neck flexed to 90 degrees)	Use trough to support VD position; tapes behind the upper and lower canines to hold open the jaws for radiographs of the tympanic bullae.	Tympanic bullae (mouth open) and frontal sinuses (mouth closed).	Ensure that the back of the head and the neck are flat to the table.
Intra-oral DV Occlusal Skull	Sternal recumbency	Rest the chin on a wooden or foam block to ensure that the head is level; a sandbag over the neck supports the position.	Nasal chambers.	A general anaesthetic is essential for this view; non-screen film is used meaning that a longer exposure time will be necessary.
Lateral Thorax (chest)	Lateral recumbency; right lateral for heart radiographs as a more consistent outline is achieved; left and right lateral for the lungs as the upper most lungfield is better aerated.	Use sandbags to bring forward the forelimbs and hold back the hindlimbs; a foam pad raises the sternum to the same height above the tabletop as the spine.	Collimate level with the 5th rib and the caudal border of the scapula.	Chest radiographs should be taken on inspiration since a superior view of the lungfields is provided.
DV. Thorax	Ventral recumbency	Draw forward the forelimbs to prevent them from obscuring the cranial thorax; a sandbag over the neck aids positioning; foam pads either side of the sternum offer support.	The centering point is between the scapulae. Collimate to ensure that the lungfields are included.	This is a good position for cardiac radiography since the VD view may cause the heart to tip to one side.
VD. Thorax	Dorsal recumbency	Use a trough to ensure that the patient is straight; draw the forelimbs well forwards with ties or sandbags.	Centre on the midpoint of the sternum.	Never use this position if the patient is dyspnoeic.
Lateral Abdomen	Lateral recumbency	Use sandbags or ties to bring forward the forelimbs; in addition the hindlimbs must be well drawn back to prevent them from obscuring the caudal abdomen; a foam wedge underneath the abdomen ensures that a straight position is achieved.	Collimate to include areas of interest such as the liver, spleen or intestines. The view may be of caudal abdomen to include the bladder.	Abdominal views are taken on expiration since this provides a more spread out view (and subsequently better visualisation) of the viscera.
VD. Abdomen	Dorsal recumbency	The patient is best supported in a trough; both fore and hind limbs should be tied to prevent them from obscuring the view.	Collimate to include areas of interest such as the liver, spleen or intestines.	Never use this position if the patient is dyspnoeic (the DV view is rarely used for abdominal radiographs since this causes compression and distortion of the viscera).
Lateral Spine	Lateral recumbency (usually right sided)	Foam padding is required beneath the chest, behind the head and between the limbs since it is essential that the spine is parallel to the table and not subject to sagging or rotation.	Collimate to include the vertebrae of interest: Cervical C1-C6, Cervico-thoracic C6-T3, Thoracic T3-T11, Thoraco-lumbar T11-L3, Lumbar L1-L7, Sacro-coccygeal L6-Cd4; centre upon L4-L5 or L5-L6 for myelography.	Spinal radiographs are carried out in a survey format since it is impossible to attain an accurate picture of the entire spine due to the divergence of the primary beam; this means that disc spaces not centred will be obscured by the shadows of adjacent vertebrae.
VD. Spine	Dorsal recumbency	Position the patient within a trough; ensure that the spine is straight by making use of foam wedges, ties and sandbags.	Collimate to include C1-C6 or C6-T3.	For radiographs of the cervical spine or thoracic junction, the x-ray beam is angled 15-20 degrees towards the patient's head.
Lateral Scapula	Lateral recumbency, affected side down.	The lower limb is drawn back and secured with a sandbag; the upper limb is secured with a tie towards the head.	Collimate to include the lower scapula; this is the shoulder blade (palpated above the humerus).	Take care to ensure that the limbs do not obscure the image.
Cd.Cr. Scapula	Dorsal recumbency	The forelimb of the affected side is drawn forwards and held in maximum extension with a tie.	Collimate to include the lower scapula.	Tilting the animal slightly over to the contra lateral side will aid positioning.
Lateral Shoulder	Lateral recumbency, affected side down.	The lower limb is drawn forwards and secured with a tie; the upper limb is pulled back.	Centre on the shoulder joint where the distal scapula meets the proximal humerus.	The head and neck should be extended.
Cd.Cr. Shoulder	Dorsal recumbency	The patient is supported within a trough; the forelimb is drawn forwards and held in maximum extension with a tie.	Centre on the shoulder joint where the distal scapula meets the proximal humerus.	Tilt the animal slightly over to the contra lateral side.
Lateral Elbow	Lateral recumbency, affected side down.	The lower limb is drawn forwards and secured with a tie; the upper limb is drawn backwards and tied or held in position with a sandbag.	Centre on the elbow joint where the distal humerus joins the proximal radius and ulna; the anconeal process (proximal notch or coronoid process (distal notch) may be points of interest.	A flexed view of the lateral elbow is useful for the assessment of degenerative joint disease.
Cd.Cr. Elbow	Dorsal recumbency	The patient is supported within a trough; affected limb is drawn towards the head and secured in maximum extension with a tie.	Centre on the elbow joint where distal humerus meets proximal radius and ulna.	Tip the patient slightly towards the contra lateral side to achieve a better view.
Cr.Cd. Elbow	Ventral or sternal recumbency.	Support the patient on either side with sandbags or foam wedges; both forelimbs are extended caudally and tied into position.	Centre on the elbow joint where distal humerus meets proximal radius and ulna.	The x-ray beam should be angled 10-15 degrees towards the tail; another Cr.Cd. technique is to position the patient in dorsal recumbency with the caudal aspect of the affected limb placed flat to the x-ray cassette (the paw is directed towards the tail).
Lateral Humerus	Lateral recumbency; affected side down.	The neck is secured in position with a sandbag; the affected limb is extended and tied whilst the non-affected (upper) forelimb is pulled back out of the way and held with a sandbag or tie.	Collimate to include the humerus (the long bone between the shoulder and elbow joints).
Cd.Cr. Humerus	Dorsal recumbency	The patient is supported with a trough; the affected limb is extended cranially and tied into place.	Collimate to include the humerus (the long bone between the shoulder and elbow joints).	As with positioning for radiography of the scapula and shoulder joint - tip the patient slightly over to the side not under investigation. Note: long object film distance unavoidable.
Cr.Cd. Humerus	Dorsal recumbency	The patient is supported within a trough with the affected limb extended caudally and tied into position.	Collimate to include the humerus (the long bone between the elbow and shoulder joints).	The humerus should lie parallel to the cassette which is not always possible if a trough is used; substitute the trough for sandbags and foam wedges if necessary.
Lateral Radius & Ulna	Lateral recumbency; affected side down.	The affected (lower) limb is drawn forwards and tied; the non-affected (upper) limb is drawn backwards out of the way and held with a tie or sandbag.	Collimate to include the radius and ulna = the 2 forearm bones; the radius articulates proximally with the humerus at the elbow joint and distally with the carpus; the olecranon (proximal ulna) forms the point of the elbow.	Positioning may be aided with the use of radiolucent sticky tape.
Cr.Cd. Radius & Ulna	Sternal recumbency	The patient is supported with sandbags or foam wedges; the affected limb is extended cranially and held in position with a tie.	Collimate to include the radius and ulna = the 2 forearm bones.	Ensure that the patient's head does not obscure the view of the desired area of collimation.
Lateral carpus and paw	Lateral recumbency affected side down.	The affected limb is extended cranially and tied into position whilst the lower limb is drawn back out of the way and held with a tie or sandbag.	Centre on the carpus (wrist joint), carpal bones or metacarpals as desired.	For radiography of individual digits, separate the toes bringing forward that to be x-rayed and holding back the rest with radiolucent sticky tape.
D.Pa. Carpus & Paw	Sternal recumbency	The forelimbs are extended cranially and tied or taped into position; the head is tilted over to the non-affected side and held out of the way with a sandbag.	Centre on the carpus (wrist), carpal bones or metacarpals as desired.	Digits may also be radiographed and separated for better definition with sticky tape.
Lateral Pelvis	Lateral recumbency	Foam padding is placed underneath the spine and sternum and also between the stifles to ensure a true lateral view.	Collimate to include the hip joint/s where the pelvis meets the proximal humerus.	If one limb only is affected, this may be placed laterally upon the cassette with the non-affected limb flexed backwards out of the way; an angled beam is required for this view.
VD. Pelvis	Dorsal recumbency	The patient is positioned within a trough; the forelimbs are secured cranially and a sandbag is draped over the sternum to ensure that the patient is straight; the stifles are rotated inwards and taped; the hind limbs are extended caudally and tied.	Collimate to include both hip joints, centering on the pubic symphysis.	This position is required for the Kennel Club/BVA Hip Dysplasia scheme; the flexed or "frog-legged" view where the hind limbs are not tied and left to fall either side of the pelvis is suitable in trauma cases where manipulation may prove painful.
Lateral Femur	Lateral recumbency; affected side down.	The lower limb is placed on the cassette with the upper limb flexed and tied vertically up out of the way; a pad beneath the hock ensures a true lateral position.	Collimate to the include femur; the long bone which runs between the hip and stifle joints.	The lower femur may be radiographed through the abdomen to prevent super-imposition of the upper limb.
Cr.Cd. Femur	Dorsal recumbency	The patient is positioned within a trough with the forelimbs secured cranially; the affected hind limb is extended caudally and tied or taped into place.	Collimate to include the femur; the long bone which runs between the hip and stifle joints.
Lateral Stifle	Lateral recumbency; affected side down.	The affected stifle is positioned laterally on the cassette; a pad beneath the hock ensures a true lateral view; the non-affected limb is tied vertically or caudally out of view.	Collimate to include the stifle joint (the knee); this is the joint sited between the distal femur and the proximal tibia and fibula.	Obese patients may benefit from a compression band to prevent super-imposition of mammary tissue or the sheath; the lateral stifle may also be radiographed with a horizontal beam.
Cd.Cr. Stifle	Sternal recumbency	The patient is supported with sandbags or foam wedges; the affected limb is extended caudally and tied or taped into place; a large sandbag draped across the rump will help to keep the animal straight.	Collimate to include the stifle joint (the knee); this is the joint sited between the distal femur and the proximal tibia and fibula.
Cr.Cd. Stifle	Dorsal recumbency	The patient is supported within a trough; the affected limb is extended and tied or taped into place; the non-affected limb may be left free.	Collimate to include the stifle joint (the knee); this is the joint sited between the distal femur and the proximal tibia and fibula.	Tilting the patient slightly away from the affected side may aid positioning and ensure a true cranio-caudal view.
Lateral Hock, Tibia & Paw	Lateral recumbency; affected side down.	The affected limb is positioned on the cassette with tapes or ties; the upper limb is drawn either forwards or backwards out of view and secured with ties or sandbags.	Centre on the hock joint - where the distal tibia and fibula meet the proximal metatarsals, the tibia/fibula - the long bones running between the hock and stifle or the paw.	For radiography of the paw, separate the digits for better definition.
Cr.Cd. Tibia	Ventral recumbency	The patient is supported within a trough with the affected limb extended and tied into place.	Centre on the tibia; the long bone running between the hock and stifle.
D.Pl. Hock	Ventral recumbency	The patient is supported within a trough with the affected limb extended and tied into place.	Centre on the hock joint where the distal tibia and fibula meet the proximal metatarsals.	Tape may be looped around the paw to aid positioning; it may be necessary to raise the cassette in order to decrease the object-film distance with this view.
D.Pl. Paw	Ventral recumbency	The patient is supported within a trough with the affected limb extended caudally and tied into place; separate the digits if desired.	Collimate to include the digit/s.	Strong, radiolucent, adhesive tape may be necessary to hold the paw in the desired position on the cassette

Tags: radiograpghy chart

Chart For Positioning & Collimation - Key Notes

Arlo Guthrie — Tue, 21 Apr 2009 07:38:18 GMT

Revision 1 posted to Revision Guide For Student Nurses - Part 2 by Arlo Guthrie on 4/21/2009 7:38:18 AM

Anatomy	Positioning	Aids	Collimation	Notes
Lateral Skull	Lateral recumbency	Foam wedges beneath muzzle to ensure that head is parallel to table; pad neck & sternum to stabilise.	Collimation depends upon the point of interest; possible areas include: cranium, zygomatic arch, mandibles, frontal sinuses, nasal turbinates, tympanic bullae & teeth.	The centering point depends upon the area of interest; the head may be tilted upwards for an improved view of the temporo-mandibular joints.
DV. Skull	Ventral recumbency	Muzzle positioned flat to the cassette; a sandbag over the neck secures the head in place.	Midline structures; ie. the frontal bone, frontal sinuses or maxillae.	Raising the cassette on a wooden block may aid positioning.
VD. Skull	Dorsal recumbency	Use trough to support VD position; foam pads will support the nose and neck, while tapes secured behind the upper canines hold the muzzle close to the plate.	Mandibles and tympanic bullae.	The head and neck must be extended; an open-mouthed oblique view variation on this position is suitable for radiographs of the nasal sinuses.
Oblique Skull	Lateral recumbency	The head is positioned within a trough to enable the skull to be angled correctly.	Tympanic bullae and temporo-mandibular joints.	The skull should be rotated 20 degrees around its long axis towards the VD position.
R.Ca. Skull (Rostro-caudal)	Dorsal recumbency (with neck flexed to 90 degrees)	Use trough to support VD position; tapes behind the upper and lower canines to hold open the jaws for radiographs of the tympanic bullae.	Tympanic bullae (mouth open) and frontal sinuses (mouth closed).	Ensure that the back of the head and the neck are flat to the table.
Intra-oral DV Occlusal Skull	Sternal recumbency	Rest the chin on a wooden or foam block to ensure that the head is level; a sandbag over the neck supports the position.	Nasal chambers.	A general anaesthetic is essential for this view; non-screen film is used meaning that a longer exposure time will be necessary.
Lateral Thorax (chest)	Lateral recumbency; right lateral for heart radiographs as a more consistent outline is achieved; left and right lateral for the lungs as the upper most lungfield is better aerated.	Use sandbags to bring forward the forelimbs and hold back the hindlimbs; a foam pad raises the sternum to the same height above the tabletop as the spine.	Collimate level with the 5th rib and the caudal border of the scapula.	Chest radiographs should be taken on inspiration since a superior view of the lungfields is provided.
DV. Thorax	Ventral recumbency	Draw forward the forelimbs to prevent them from obscuring the cranial thorax; a sandbag over the neck aids positioning; foam pads either side of the sternum offer support.	The centering point is between the scapulae. Collimate to ensure that the lungfields are included.	This is a good position for cardiac radiography since the VD view may cause the heart to tip to one side.
VD. Thorax	Dorsal recumbency	Use a trough to ensure that the patient is straight; draw the forelimbs well forwards with ties or sandbags.	Centre on the midpoint of the sternum.	Never use this position if the patient is dyspnoeic.
Lateral Abdomen	Lateral recumbency	Use sandbags or ties to bring forward the forelimbs; in addition the hindlimbs must be well drawn back to prevent them from obscuring the caudal abdomen; a foam wedge underneath the abdomen ensures that a straight position is achieved.	Collimate to include areas of interest such as the liver, spleen or intestines. The view may be of caudal abdomen to include the bladder.	Abdominal views are taken on expiration since this provides a more spread out view (and subsequently better visualisation) of the viscera.
VD. Abdomen	Dorsal recumbency	The patient is best supported in a trough; both fore and hind limbs should be tied to prevent them from obscuring the view.	Collimate to include areas of interest such as the liver, spleen or intestines.	Never use this position if the patient is dyspnoeic (the DV view is rarely used for abdominal radiographs since this causes compression and distortion of the viscera).
Lateral Spine	Lateral recumbency (usually right sided)	Foam padding is required beneath the chest, behind the head and between the limbs since it is essential that the spine is parallel to the table and not subject to sagging or rotation.	Collimate to include the vertebrae of interest: Cervical C1-C6, Cervico-thoracic C6-T3, Thoracic T3-T11, Thoraco-lumbar T11-L3, Lumbar L1-L7, Sacro-coccygeal L6-Cd4; centre upon L4-L5 or L5-L6 for myelography.	Spinal radiographs are carried out in a survey format since it is impossible to attain an accurate picture of the entire spine due to the divergence of the primary beam; this means that disc spaces not centred will be obscured by the shadows of adjacent vertebrae.
VD. Spine	Dorsal recumbency	Position the patient within a trough; ensure that the spine is straight by making use of foam wedges, ties and sandbags.	Collimate to include C1-C6 or C6-T3.	For radiographs of the cervical spine or thoracic junction, the x-ray beam is angled 15-20 degrees towards the patient's head.
Lateral Scapula	Lateral recumbency, affected side down.	The lower limb is drawn back and secured with a sandbag; the upper limb is secured with a tie towards the head.	Collimate to include the lower scapula; this is the shoulder blade (palpated above the humerus).	Take care to ensure that the limbs do not obscure the image.
Cd.Cr. Scapula	Dorsal recumbency	The forelimb of the affected side is drawn forwards and held in maximum extension with a tie.	Collimate to include the lower scapula.	Tilting the animal slightly over to the contra lateral side will aid positioning.
Lateral Shoulder	Lateral recumbency, affected side down.	The lower limb is drawn forwards and secured with a tie; the upper limb is pulled back.	Centre on the shoulder joint where the distal scapula meets the proximal humerus.	The head and neck should be extended.
Cd.Cr. Shoulder	Dorsal recumbency	The patient is supported within a trough; the forelimb is drawn forwards and held in maximum extension with a tie.	Centre on the shoulder joint where the distal scapula meets the proximal humerus.	Tilt the animal slightly over to the contra lateral side.
Lateral Elbow	Lateral recumbency, affected side down.	The lower limb is drawn forwards and secured with a tie; the upper limb is drawn backwards and tied or held in position with a sandbag.	Centre on the elbow joint where the distal humerus joins the proximal radius and ulna; the anconeal process (proximal notch or coronoid process (distal notch) may be points of interest.	A flexed view of the lateral elbow is useful for the assessment of degenerative joint disease.
Cd.Cr. Elbow	Dorsal recumbency	The patient is supported within a trough; affected limb is drawn towards the head and secured in maximum extension with a tie.	Centre on the elbow joint where distal humerus meets proximal radius and ulna.	Tip the patient slightly towards the contra lateral side to achieve a better view.
Cr.Cd. Elbow	Ventral or sternal recumbency.	Support the patient on either side with sandbags or foam wedges; both forelimbs are extended caudally and tied into position.	Centre on the elbow joint where distal humerus meets proximal radius and ulna.	The x-ray beam should be angled 10-15 degrees towards the tail; another Cr.Cd. technique is to position the patient in dorsal recumbency with the caudal aspect of the affected limb placed flat to the x-ray cassette (the paw is directed towards the tail).
Lateral Humerus	Lateral recumbency; affected side down.	The neck is secured in position with a sandbag; the affected limb is extended and tied whilst the non-affected (upper) forelimb is pulled back out of the way and held with a sandbag or tie.	Collimate to include the humerus (the long bone between the shoulder and elbow joints).
Cd.Cr. Humerus	Dorsal recumbency	The patient is supported with a trough; the affected limb is extended cranially and tied into place.	Collimate to include the humerus (the long bone between the shoulder and elbow joints).	As with positioning for radiography of the scapula and shoulder joint - tip the patient slightly over to the side not under investigation. Note: long object film distance unavoidable.
Cr.Cd. Humerus	Dorsal recumbency	The patient is supported within a trough with the affected limb extended caudally and tied into position.	Collimate to include the humerus (the long bone between the elbow and shoulder joints).	The humerus should lie parallel to the cassette which is not always possible if a trough is used; substitute the trough for sandbags and foam wedges if necessary.
Lateral Radius & Ulna	Lateral recumbency; affected side down.	The affected (lower) limb is drawn forwards and tied; the non-affected (upper) limb is drawn backwards out of the way and held with a tie or sandbag.	Collimate to include the radius and ulna = the 2 forearm bones; the radius articulates proximally with the humerus at the elbow joint and distally with the carpus; the olecranon (proximal ulna) forms the point of the elbow.	Positioning may be aided with the use of radiolucent sticky tape.
Cr.Cd. Radius & Ulna	Sternal recumbency	The patient is supported with sandbags or foam wedges; the affected limb is extended cranially and held in position with a tie.	Collimate to include the radius and ulna = the 2 forearm bones.	Ensure that the patient's head does not obscure the view of the desired area of collimation.
Lateral carpus and paw	Lateral recumbency affected side down.	The affected limb is extended cranially and tied into position whilst the lower limb is drawn back out of the way and held with a tie or sandbag.	Centre on the carpus (wrist joint), carpal bones or metacarpals as desired.	For radiography of individual digits, separate the toes bringing forward that to be x-rayed and holding back the rest with radiolucent sticky tape.
D.Pa. Carpus & Paw	Sternal recumbency	The forelimbs are extended cranially and tied or taped into position; the head is tilted over to the non-affected side and held out of the way with a sandbag.	Centre on the carpus (wrist), carpal bones or metacarpals as desired.	Digits may also be radiographed and separated for better definition with sticky tape.
Lateral Pelvis	Lateral recumbency	Foam padding is placed underneath the spine and sternum and also between the stifles to ensure a true lateral view.	Collimate to include the hip joint/s where the pelvis meets the proximal humerus.	If one limb only is affected, this may be placed laterally upon the cassette with the non-affected limb flexed backwards out of the way; an angled beam is required for this view.
VD. Pelvis	Dorsal recumbency	The patient is positioned within a trough; the forelimbs are secured cranially and a sandbag is draped over the sternum to ensure that the patient is straight; the stifles are rotated inwards and taped; the hind limbs are extended caudally and tied.	Collimate to include both hip joints, centering on the pubic symphysis.	This position is required for the Kennel Club/BVA Hip Dysplasia scheme; the flexed or "frog-legged" view where the hind limbs are not tied and left to fall either side of the pelvis is suitable in trauma cases where manipulation may prove painful.
Lateral Femur	Lateral recumbency; affected side down.	The lower limb is placed on the cassette with the upper limb flexed and tied vertically up out of the way; a pad beneath the hock ensures a true lateral position.	Collimate to the include femur; the long bone which runs between the hip and stifle joints.	The lower femur may be radiographed through the abdomen to prevent super-imposition of the upper limb.
Cr.Cd. Femur	Dorsal recumbency	The patient is positioned within a trough with the forelimbs secured cranially; the affected hind limb is extended caudally and tied or taped into place.	Collimate to include the femur; the long bone which runs between the hip and stifle joints.
Lateral Stifle	Lateral recumbency; affected side down.	The affected stifle is positioned laterally on the cassette; a pad beneath the hock ensures a true lateral view; the non-affected limb is tied vertically or caudally out of view.	Collimate to include the stifle joint (the knee); this is the joint sited between the distal femur and the proximal tibia and fibula.	Obese patients may benefit from a compression band to prevent super-imposition of mammary tissue or the sheath; the lateral stifle may also be radiographed with a horizontal beam.
Cd.Cr. Stifle	Sternal recumbency	The patient is supported with sandbags or foam wedges; the affected limb is extended caudally and tied or taped into place; a large sandbag draped across the rump will help to keep the animal straight.	Collimate to include the stifle joint (the knee); this is the joint sited between the distal femur and the proximal tibia and fibula.
Cr.Cd. Stifle	Dorsal recumbency	The patient is supported within a trough; the affected limb is extended and tied or taped into place; the non-affected limb may be left free.	Collimate to include the stifle joint (the knee); this is the joint sited between the distal femur and the proximal tibia and fibula.	Tilting the patient slightly away from the affected side may aid positioning and ensure a true cranio-caudal view.
Lateral Hock, Tibia & Paw	Lateral recumbency; affected side down.	The affected limb is positioned on the cassette with tapes or ties; the upper limb is drawn either forwards or backwards out of view and secured with ties or sandbags.	Centre on the hock joint - where the distal tibia and fibula meet the proximal metatarsals, the tibia/fibula - the long bones running between the hock and stifle or the paw.	For radiography of the paw, separate the digits for better definition.
Cr.Cd. Tibia	Ventral recumbency	The patient is supported within a trough with the affected limb extended and tied into place.	Centre on the tibia; the long bone running between the hock and stifle.
D.Pl. Hock	Ventral recumbency	The patient is supported within a trough with the affected limb extended and tied into place.	Centre on the hock joint where the distal tibia and fibula meet the proximal metatarsals.	Tape may be looped around the paw to aid positioning; it may be necessary to raise the cassette in order to decrease the object-film distance with this view.
D.Pl. Paw	Ventral recumbency	The patient is supported within a trough with the affected limb extended caudally and tied into place; separate the digits if desired.	Collimate to include the digit/s.	Strong, radiolucent, adhesive tape may be necessary to hold the paw in the desired position on the cassette