Radiology Clinical IV
~~~Spine & Bony
Thorax~~~~~
Image Review
The following information is only a personal suggested guideline to follow when positioning for Spine and
Bony Thorax exams.
For additional information on positioning of these
exams, please reference your Radiographic
Positioning and Related Anatomy Textbook.
Cervical
Spine*Good
positioning Images will
always be on the right.
Lateral C-Spine• CR ┴ to IR• Relax/drop shoulders• Body in lateral position • Protract chin (to get mandibular
rami away from the anterior arch of C-1)• Direct CR to C4• Expiration
Artifact and poor centering and technique
Artifact and C7 is not visualized.
Motion & no marker
Image ok, just showing pathology of previous surgery.
Poor centering and technique, due to patient moving and causing AEC chambers to not hit appropriate anatomy. Optional: Choose manual technique.
A
B
F
E
D
C
T-1
T-1
Superior
Articular
Process
Inferior Articular
Process
Zygapophyseal joint
Spinous Processor C7Vertebral Prominens
Intervertebral Disc Space
Body
AP C-Spine• CR is 15°-20° cephalad• Body in AP position• Ensure tip of mandible to
base of skull is ║ with CR<• Direct CR to C4
Artifact and poor positioning of headAnd no marker
Image ok, just showing pathology of previous surgery.
4
5
6
7
2
3
4
5
6
7
Red line = chin, pink line = base of skull.Head is flexed downward, causing chin to superimpose on top of upper C-spine.
4
5
6
7 CR
Red line = chin, pink line = base of skull.Head is flexed downward, causing chin to superimpose on top of upper C-spine.
3
4
5
6
7
2
3
4
5
6
7
Red line = chin, pink line = base of skull.Head is extended to far back, causing base of skull to superimpose on top of upper C-spine.
3
4
5
6
7
2
3
4
5
6
7
CR
Red line = chin, pink line = base of skull. Left Image shows the head over extended, causing the base of skull to superimpose on top of upper C-spine. Right image shows how this positioning error took place viewing the patient from the side.
CR
Left Image is an excellent AP Cervical Spine ~ Right Image is an example of how you should step to the side, and view the patient’s lateral side to ensure that the “lower mandible to base of skull” line is parallel with the CR.
Oblique C-Spine• CR 15°cephalad for AP
or 15° caudad for PA• Body is rotated 45°• Protract chin• Direct CR to C4
Positioning- over rotatedCR – not centered and no angleExposure – due to being not centered
Repeatable error?
Anatomy - patient’s mandible is in the way of the c-spine. No marker
Repeatable error?
Positioning – under rotated & Patient’s mandible is in the way of the c-spine.
Repeatable error?
LPO will show right intervertebral foramina (the ones closer to the CR)
Extremely poor positioning ~ possible due to patient’s inability to cooperate.
Patient’s mandible is in the way of the c-spine.
Patient’s mandible is in the way of the c-spine.
A
B
C
DE
Hyoid Bone
Intervertebral Foramen
Pedicle
InferiorVertebralNotch
SuperiorVertebralNotch
Odontoid C-Spine• CR is ┴ to IR• Body in AP position• Open mouth to ensure upper
incisors are ║ with base of skull
• Ensure no rotation of skull• Direct CR into open mouth
Positioning - Head is over extended and slightly tilted to the left. Poor collimation
Repeatable error?
Positioning - Head is over extended too far back .
Repeatable error?
Positioning - Head is flexed too far forward. No Markers
Repeatable error?
Poor positioning:A) Upper teeth B) Motion of lower teeth C) Base of skull D) Motion of moving mandible
AB
C
D
Even almost perfect positioning leads to no visualization of the odontoid. In this case, if the exam was for trauma, you would have to do an additional Judd or Fuchs position.
Besides excellent positioning, the mouth is also opened appropriately. To show any displacement of C1 & C2 laterally. Sometimes fillings or crowns of the back molars prohibit this visualization.
Pathology - Ankylosing Spondylitis = Calcification with ossification (formation of bony ridges between vertebrae), creating stiffness and lack of joint mobility.
ThoracicSpine
AP T-Spine• CR ┴ to IR• Body in AP position• Flex legs• Direct CR to T7• Expiration• Opt. If using a long exposure
technique-Suspending respiration on inspiration is recommended.
Repeatable error? Incorrect CR centering - Clipped anatomy
Repeatable error? Incorrect CR centering - Clipped anatomy
Poor image, possibly due to using AEC. Manually set, long exposure techniques help blur out mediastinal structures to better visualize costovertebral joints. Note: Right adrenal gland calcification.
Poor image, possibly due to using AEC. Patient is obviously barrel chested causing lower T-spines to be too light. Manually set, long exposure techniques help blur out mediastinal structures to better visualize costovertebral joints.
Pathology - Scoliosis
Lateral T-Spine• CR ┴ to IR• Body in Lateral position• Flex legs• Ensure NO rotation• Direct CR to T7• Expiration• Opt. If using a long exposure technique-
Suspending respiration on inspiration is recommended.
Pathology – showing previous surgery.
Poor image, possibly due to using AEC. Manually set, long exposure techniques help blur out lung markings to better visualize the spine.
Better Technique BEST Technique!
Swimmers – suggestion:Look for the wishbone.
The clavicles create the wishbone ends. Then between them will be the
first rib as it attaches to T-1. C-7 is located just above this spine.
Swimmers• CR ┴ to IR(*3°-5° caudad<)• Body in Lateral position• Separate shoulders• Direct CR to T1• Expiration• Opt. Long exposure technique
Oblique T-Spine• CR ┴ to IR• Rotate whole body 20° from true
lateral to create a 70° from plane of table.
• Direct CR to T7• Expiration• Opt. If using a long exposure technique-
Suspending respiration on inspiration is recommended.
A C
Oblique T-SpineRotate body 20° from true lateral, to create a 70° oblique from plane of table.
B
Oblique T-Spine• Anterior obliques will visualize the
zygapophyseal joints closest to the IR.• Posterior obliques will visualize
zygapophyseal joints closest to the CR.
Superior Articular Process
Inferior Articular Process
Zygapophyseal joint
A
B
DG
HC
EF
Body
Vertebral Foramen
Transverse Process
Costotransverse Joint
Costovertebral Joint
Pedicle
LaminaSpinous Process
Lumbar Spine
AP L-Spine• CR ┴ to IR• Flex legs• Ensure NO rotation of pelvis• Direct CR to iliac crest• Expiration
Repeatable error?Incorrect CR/IR alignment –
Clipped anatomy
Repeatable error? Marker in anatomy
Repeatable error? Marker in anatomy
Pathology – Gun shot.
Pathology – Previous surgery. Kyphoplasty
Pathology – showing previous surgery.
Pathology – showing Scoliosis.
Lateral L-Spine• CR ┴ to IR• Flex legs• Ensure NO rotation• Ensure NO “sag”• Direct CR to iliac crest• Suspend/Expiration
Repeatable error?Structures are not shown – positioning
and no marker
Double exposure, and clipped spinous processes.
Pathology – showing previous surgery(almost clipped L1 with centering).
Pathology – showing previous surgery-Kyphoplasty
Pathology – Impacted compression fracture/MRI
Poor marker placement.
A
BC
D
E
F
Intervertebral Disc Space
BodyIntervertebral
Foramina
Pedicle
Inferior Vertebral Notch
Superior Vertebral Notch
Oblique L-Spine• CR ┴ to IR• Rotate whole body 45°& align
spine with IR• Direct CR to 1” above iliac
crest & 2” medial to up side ASIS
• Suspend/Expiration
C
E
F
A
G
D
B
Nose
Ear
Body
Foot
Zygapophyseal Joint
Eye
Neck
The Scotty Dog
Transverse Process
Superior Articular Process
Lamina
Inferior Articular Process
Zygapophyseal Joint
Pedicle
Pars Interarticilaris
L5-S1 L-Spine• CR ┴ to IR• Flex legs• Ensure NO rotation• Ensure NO “sag”• Direct CR 1.5” inferior to iliac
crest & 2” posterior to ASIS• Suspend/Expiration
Repeatable error?
Incorrect CR/IR alignment – Clipped anatomy
Repeatable error?Incorrect Centering–
Clipped anatomy
Left Image shows the “cake top” or “pop can” effect of the vertebral bodies when no radiolucent support is used under the waist.
Left Image shows white ovals of the “cake top”or “pop can” effect of the vertebral bodies when no radiolucent support is used under the waist.
Left Image shows that no radiolucent support was used under the wait and possibly no caudad angle of the CR was used, causing the L5-S1 space to not be open. The yellow dotted lines show how the iliac crests are not superimposed.
Flexion & Extension L-Spine
Flexion – both are good images
Extension– both are good images
Sacrum
&
Coccyx
AP Sacrum• CR is 15° cephalad (to the nose)
• Body in AP position• Flex legs• Direct CR 2” superior to the
pubic symphysis
Left Image shows that the patient needs to empty their bladder before the x-ray is taken.
Left Image shows not enough cephalad angle. See how sacral foramina are still slightly foreshortened as compared to the image on the right.
AP Coccyx• CR is 10° cephalad (to the toes)• Body in AP position• Flex legs• Direct CR 2” superior to the
pubic symphysis
Left Image shows that the patient needs to empty their bladder before the x-ray is taken.
Artifact - patient needs to remove their underwear before the x-ray is taken.
Repeatable Error?
Lateral Sacrum/Coccyx• CR ┴ to IR• Flex legs• Ensure NO rotation• Ensure NO “sag”• Direct CR 3”-4” posterior to
ASIS
Does not appear as though support was used under the waist to help make the spine parallel with the IR. Image is also very gray from poor technique choice.
Image appears as though the body is rotated.
Image is better but still appears as though support has not been used under the waist to help make the spine parallel with the IR. Could have centered slightly more posterior as distal sacrum and coccyx are almost clipped.
Sacroiliac Joints
Axial S-I Jts• CR is 30°-35° cephalad• Body in AP position• Flex legs slightly• Direct CR 2” inferior to the
ASIS
Oblique S-I Jts• CR is ┴ to the IR• Body in AP position, then
rotated 20°-25° each way• Direct CR 1” medial to
upside ASIS
BonyThora
x
Rib Techniques“Long” exposure is best for fine detail of ribs.(Low Ma & 2-3 sec)
• Pt holds their breath in for upper ribs and out for lower ribs
• Expose on suspended respiration
Oblique RibsHow to remember which oblique to do in order to get the elongated view of the ribs:• Turn the spine away from
the effected side• AP towards IR and• PA “Away” from IR
Image on the left - Uses AEC and is not ideal for rib x-rays. Image on the right - Uses a manually set long exposure technique which best visualizes rib detail.
Image on the left – poor detail due to inappropriate KvP, poor histogram settings for processing image or due to using AEC.
Image on the left – slightly better technique, AEC was probably still used but at a low KvP range to enforce a longer exposure.
Image on the left - Uses AEC and is not ideal for rib x-rays. Image on the right - Uses a manually set long exposure technique which blurs out heart and lungs to best visualizes rib detail.
Image on the left – Manually set technique using long exposure, but the patient’s breast needs to be moved out of the way. Ask patient to hold their breast out of the way.
Sternum Techniques“Breathing” Technique is best for viewing the sternum in the RAO position. Low MA and 2-3 second exposure.• Pt exhales slowly to blur
out lung markings and ribs.
RAO Sternum• CR is ┴ to the IR• 40” SID• Body in 15°-20° RAO
(Deep chested thorax requires less rotation than thin-chested)
• Direct CR to mid-sternum and 1” to left of midline
• Breathing Technique
Lateral Sternum• CR is ┴ to the IR• 72” SID• Body in true lateral position• Arms back• Direct CR to mid-sternum • Expiration
S/C Jts• CR is ┴ to the IR• 40” SID• Direct CR T2/T3 (3”
inferior to vertebral prominens)
• Expiration
Both Oblique SC Jts• CR is ┴ to the IR• 40” SID• Rotate body 10°-15° each way for
RAO and LAO• Direct CR (T-3) 3” inferior to
vertebral prominens & 1”-2” to upside from midline
• Expiration
With lesser body rotation (5°-10°) the upside S/C joint will be visualized.
~The End~