HMI203 Pre-Placement Passport Positioning/Parameters

In God's hands now

PA Skull

Broad FS, 100cm

70kVp, 20mAs

Orbitomeatal line parallel to floor/parpendicular to IR

Straight tube

CR: Midline exiting through glabella

PA Caldwell Skull

Broad FS, 100cm

70kVp, 20mAs

Orbitomeatal line parallel to floor/perpendicular to IR

Tube angle 15 degrees caudal

CR: Midline exiting through nasion

AP Axial Skull/Townes

Broad FS, 100cm

80kVp, 30mAs

Orbitomeatal line parallel to floor/perpendicular to IR

Tube angle 30 degrees caudal

CR: midline 5cm above glabella

Lateral Skull

Broad FS, 100cm

75kVp, 15mAs

Inferior orbitomeatal line parallel to floor/perpendicular to IR

Straight tube

CR: 5cm above external auditory meatus

Submento-Vertical Skull

Broad FS, 100cm

75kVp, 20mAs

Inferior orbitomeatal line perpendicular to floor/parallel to IR

Straight tube

CR: midline 4cm below mandibular symphysis

PA Caldwell Face

Broad FS, 100cm

80kVp, 25mAs

Orbitomeatal line parallel to floor/perpendicular to IR

Tube angle 25 degrees caudal

CR: midline exiting through nasion

PA Occipitomental/Waters Face

Broad FS, 100cm

75kVp, 25mAs

Orbitomeatal line angled 45 degrees up

Straight tube

CR: Midline exiting through acanthion/anterior nasal spine

PA Occipitomental 30/Extended Waters Face

Broad FS, 100cm

75kVp, 25mAs

Oribitomeatal line angled 45 degrees up

Tube angle 30 degrees caudal

CR: Midline exiting through acanthion/anterior nasal spine

Lateral Face

Broad FS, 100cm

70kVp, 10mAs

Inferior orbitomeatal line parallel to floor

Straight tube

CR: Midway between EAM and outer canthus

AP Slit Townes/Zygomatic Arches Face

Broad FS, 100cm

80kVp, 30mAs

Orbitomeatal line parallel to floor/perpendicular to IR

Tube angle 30 degrees caudal

CR: Midline 2.5cm superior to nasion

PA Caldwell 15-20 Sinus View

Broad FS, 100cm

75kVp, 25mAs

Orbitomeatal line angled 15-20 degrees up

Straight tube

CR: Midline exiting through nasion

PA Occipitomental Sinus View

Broad FS, 100cm

75kVp, 30mAs

Orbitomeatal line angled 45 degrees up, MOUTH OPEN

Straight tube

CR: Midline exiting through acanthion

PA Mandible

Broad FS, 100cm

70kVp, 20mAs

Orbitomeatal line parallel to floor/perpendicular to IR

Straight tube

CR: Midline exiting at junction of lips

Lateral Mandible

Broad FS, 100cm

70kVp, 10mAs

Inferior orbitomeatal line parallel to floor/perpendicular to IR

Straight tube

CR: 5cm inferior to midpoint between EAM and outer canthus

OPG

Head resting against temporal supports

Midsagittal plane aligned with vertical laser

Frankfort plane (Infraorbital margin to superior edge of EAM) aligned with horizontal laser AKA parallel to floor

Canine plane aligned with canine laser

Tongue resting against roof of mouth

Correct OPG

Gentle smile

No rotation

No bite overlap of top and bottom teeth

No preventable artefacts visible

Has sharp resolution of teeth, roots & ‘Lamina Dura’

OPG ERROR

Tongue not placed at roof of mouth

Large dark shadow over maxillary teeth between palate and dorsum of tongue

Fix: Get patient to rest tongue at top of mouth

OPG ERROR

Slumped position/hyperextended neck

White opacity from ghosting of cervical spine in the middle

Fix: Get patient to step fully into the machine so C-spine is straight, not extended forwards

OPG ERROR

Chin tipped too high

Slight frown/small ‘W’ shaped appearance of medial section of mandible, hard palate superimposed on roots of maxillary teeth, maxillary incisors blurred and magnified, mandible is broad/flat, condyles extend to edge of film

Fix: Get patient to lower chin slightly so that Frankfort plane is parallel to floor

OPG ERROR

Chin tipped too low

“V-shaped” jaw/Joker smile appearance, condyles extend to top of film and may be cut off, spine forms arch

Fix: Get patient to raise chin slightly so that Frankfort plane is parallel to floor

OPG ERROR

Patient too far forward

Anterior teeth blurry, small, and narrow, spine visible on sides of image

Fix: Ensure both top and bottom teeth are inside the grooves

OPG ERROR

Patient too far back

Anterior teeth blurry and wide, ghosting of mandible and spine, condyles close to edge of film

Fix: Ensure both top and bottom teeth are inside the groves

OPG ERROR

Head tilted to side

Condyles not equal in height, nasal structures distorted

Fix: Ensure IPL is parallel to floor

OPG ERROR

Heat turned to one side/rotated

Teeth wider on one side compared to other, mandibular ramus wider on same side

Fix: Ensure midsagittal plane is aligned with vertical laser

OPG ERROR

Patient movement

Blur and step defects in inferior border of mandible

Fix: Repeat and ensure patient does NOT MOVE during the scan