Exam 1 Flashcards
Why Xray
diagnostic procedure
relates an understanding of patient anatomy and physiology communicates data
dictates management (chiropractic, medical, both, other)
Criteria for Ordering Xrays
unexplained weight loss
personal history of cancer
unexplained fever
age more than 50 years
intravnous drug use
prolonged corticosteroid use
severe, unremitting pain at night
trauma sufficient to sauce fracture or injury
pain that worsens when the patient is lying down features of cauda equina syndrome
urinary retention
blateral neurologic signs or symptoms saddle anesthesia (p. 207)
Never Xray without
history and physical exam findings
Purpose of Imaging Studies
assist clinical impression (diagnosis) and management
contribute to clinical picture
evaluation of suspected pathology, biomechanics (scoliosis, components
of subluxation)
Defensive Radiology
(to rule out pathology) doesn’t work because:
- image needs interpreting
- insensitive to eary disease
- correlation with clinical symptoms is poor (e.g., osteophyte that
doesn’t cause pain)
Plain Film Radiography
x-ray exam without contrast media show osseous pathology
shows mal-alignment
inexpensive
has poor sensitivity to early disease
Xray principles
- high energy short-wave electromagnetic radiation
- penetrates various materials
- variable attenuation of the xray beam – influenced by the atomic
number of the structure (denser the structure, greater the
attenuation, less blackening of the film) - ionizes atoms (removes electrons)
Radiodense
= dense, white, opaque, radiopaque
Lucent
= black/dark, radiolucent
Materials of Different Densities
(darkest to lightest) air
fat (oil)
water
bone metal
Magnification
related to divergence of xray beam from xray tube
Radiographic Distortion
unequal magnificaiton secondary to:
- position from the central ray
- position from the image receptor
Anatomical Distortion
radiographic: unequal magnification
anatomic:
Stress Radiography
used in cervical and lumbar spine, AC joint, ankle, knee, show gamekeepers thumb
Fluoroscopy
looking at fluoroscent plate itself, rather than film for evaluation of motion – gi, musculoskeletal image is intensified to reduce radiation dose time-dependent
loss of resolution (using fewer photons due to long patient exposure time)
Linear Tomography
blurs anatomy above and below the object plane (fulcrum) by moving tube and film during exposure to give appearance of an image slice
replaced by CT
Aging a Patient by X-ray
40 signs of degeneration
Computerized Tomography
x-rays combined with computers
Godrey Housfield, 1972 prototype, 1979 Nobel Prize with Allan Cormack tube rotates around patient
very thin fan-shaped beam of x-ray gives thin slices
measures tissue density – calculates amount of x-ray that gets through;
does 1000s of calculations to assign each area a grayscale tone data collected by sensors (no film)
Advantages:
- enhances soft tissue contrast
- removes overlaying anatome may require contrast enhancement for
- CT myelography
- abdomen
- evaluation of aneurysm
bone cortex is white
can be done in bone window or soft tissue window
Housfield Unit
unit of attenuation (ability to stop x-ray) CT # of water=0; bone=+1000; fat=-50
Plan Scan
for correlation with subsequent axial images each slice is collimated to 3-10 mm
Contrast Media in Radiography
high atomic weight compounds:
1. Iodine – used more frequently, intravenous or orally; can cause
allergic reaction; check first for renal function for clearance (BUN,
creatinine); used for
- vascular contrasts
- myelographic contrast
- gi contrasts
2. Barium – gi examinations only, mild reactions (colong cancer, diverticulitis, polyps)
Myelography
(myelo=nerve)
contrast media injected in the subarachnoid space under fluoroscopy largely replaced by MR and CT
Arthrography
injection of iodinated contrast media into a joint
Discography
contrast examination of disc contents
a diagnostic challenge – done to see if patient responds (says ouch)
Intravenous Pyelogram
IVU (urogram)
contrast examination of urinary tract
Radionuclide Imaging
technetium (Tc) infected, oral, inhaled; tagged to other substances to accentuate end-organ uptake
the radioisotope decays, emitting gamma radiation (to stabilize the nucleus)
gamma camera detects the radiation emitted from the body
Bone Scans
radionuclide
technetium (Tc 99) bound to a phosphate compound
hot spots appear darker
evaluates bone pathophysiology and blood supply good for metastatic disease, infection, Paget’s disease sensitive to early disease but not specific
If it looks normal, you can believe it is.
Lung Scans
radionuclide
perfusion (infected)
ventilation (inhaled)
SPECT
Single Photon Emission Computed Tomography
rotation of a photon detector array around body to acquire data from
multiple angles
used for brain, cardiac, bone (spondylolisthesis)
DEXA
Dual Energy X-ray Absorptimetry
beams of xrays at 2 energy levels to determine bone density
best way to quantify osteoporosis
gives T-score: number of standard deviations from young adults normals;
decreases –1 for every 10% of bone lost T –1 or higher, normal
-2.5 to –1 = osteopenia
PET
Positron Emission Tomography
injection of FDG (fluorodeoxyglucose) – molecule of glucose attached to
an atom of radioactive fluor (tumors use lots of glucose)
fluor emits positron which collides with an electron, liberating burst of
energy, gamma rays detected by PET scanner
Ultrasound
images soft tissue structures (not bone or air)
common: galbladder, aneurysm, kidney, liver, obstetrics
uses piezoelectric effect from transducer (crystal and electric current) nonionizing
reflection of beam from interfaces between tissues produces image
MRI
nonionizing
excellent soft tissue contrast
analyzes magnetic spin properties of hydrogen nuclei
Magnet - .2-1.5 Tesla (20,000X magnetic field of earth: magnetic field of
earth is .5 Gauss; 1T=10,000G); superconducting, permanent or resistive (supercooled)
How MR works
H proton has charge and spin, therefore has magnetic field and behaves as a dipole magnet
magnet creates net magnetic moment of H with tissues; H protons rotate or precess at a certain frequency
with correct RF, protons resonate (spin) together (42.58 MHz/T)
RF pulse is manipulated to tils H magnetic field a set amount (90 or 180o) RF pulse removed, magnetic fields realign with magnetic field
weak RF signal produced and detected by scanner
MR Terminology
area of high-intensity signal = white/light
areas area of low signal intensity = dark/black area
T1 v. T2 weighted
manipualtion of RF pulse and time of signal detection results in images of differing contrast
TR = repetition time (time spent pulsing in)
TE = echo time (listening time, with RF turned off)
T1: short TR (800), short TE (30 msec); black CSF T2: long TR (2,000), long TE (90); white CSF
Spin Density: long TR, short TE
Contraindications to MR
cerebral clips (but gi staples ok) [mascara, tattos show up as metal artifact]
Contrast Agents in MR
gadolinium intravenously, inert
increases signal intensity with pathological tissue on T1 images
doesn’t cross intact BBB (shows breakdown of BBB)
enhances tumors
enhances scar tissue
makes pathological fluid bright (white)
used to evaluate post-surgical fibrosis of lumbar spine; fibrosis brightens,
disc does not
Routine Cervical View
lateral
AP open mouth
AP lower
[other: swimmers, obliques, fl/ext, pillars, Fuchs, base posterior]
Lateral Cervical
must include bottom of occiput to top of T1 do first in trauma? points of interest (look for): - alignment - pre-cervical soft tissue space - osteophytes - sella turcica
Harris’s Ring
superior facet of C2 and transverse of C2?
AP Lower Cervical
must include C3-T1 points of interest:
- facets
- uncinates
- spinouses
- lung apices
- trachea (narrows at rima glottidis)
- carotids (not vertebrals)
AP Open Mouth
Oc/C1, C1/C2, dens
points of interest: odontoid fracture, Jefferson fracture (post and ant arches)
Cervical Obliques
taken to look at IVFs
IVFs named for vert above (C4/C5 IVF = C4 IVF)
named for part of body against the film
draw a line through the bodies to divide left and right (same/opposite side
as IVF)
CAOS – cervical anterior obliques same side: IVFs shown are the same
side as first letter of film name (eg RAO) and everything else is opposite, including lumbars CLAP
CL
AP
RAO cervical - shows Right IVFs
LAO cervical - RPO cervical LPO cervical
Left IVFs Left IVFs Right IVFs
anatomy to look at: IVF, uncinates, facets, odontoid
Cervical Flexion Extension
normal flexion:
- front of disc gets smaller, back should open up (sagittal rotation)
- anterior translation of vert normal extension: opposite above
Thoracic Views
AP and Lateral
T1-T12
posterior gutter = lowest point in lung field (fluid collects); look for normally deep angle
Lumbar Spine
T12-S1
Required views: AP and Lateral
other: obliques, spots AP/lateral LS, kinematic
AP Lumbar/APLP
T12-Pelvis – need L1 to ischial tuberosities
points of interest: aorta, abdominal/pelvic viscera
Kohler’s teardrop
where pectineal line meets acetabulum
Inverted Napoleon Hat Sign
indicates spondylolisthesis, do lateral, obliques to check?
Lateral Lumbar
(can see IVFs)
L1-S1
points of interest: retrolisthesis, aorta
Lumbar Obliques
anterior recumbent (better) or posterior upright shows pars and facets (not IVFs) Scotty Dog: - nose = transverse process - ear = superior articular process - body = lamina - front leg = inferior articular process - neck = pars interarticularis CLAP: RAO shows left pars LAO show right pars RPO shows right pars LPO shows left pars
CT vs. MR
CT: bone cortex is white MR: bone cortex is black
Shoulder
see AC/GH joints
views: AP internal and external, Grashey, Stress Views
AP External – taken with epicondyles perpendicular to buckey; see
greater tuberosity
AP Internal – greater tuberosity not prominent
Elbow
Routine: AP and lateral
other: external rotation
AP – elbow is extended; looking at radial head and tuberosities Lateral – positioning is important; looking at radial head, fat pads
Wrist/Hand
Routine: PA, Lateral, Oblique
other: ulna deviated
PA – looking at carpals with joint space of 2-3 mm
Lateral – positioning critical, looking at scaphoid alignment Oblique – looking joint space between trapezium and trapezoid
Knee
Routine: AP, Lateral, open joint
other: Merchant, Tangential
AP – tibial/femoral joint, CPPD, tibial spines
Lateral – 60o flexion; Patellar/femoral joint, patella position
Open joing – to see in intercondylar fossa, groove for popliteus tendon?
Ankle
Routine: AP, Lateral, Oblique
other: stress views
AP – talotibial joint; looking for subchondral fracture, alignment, swelling Oblique – tibio-fibular space
Lateral – taken lateral side down; see talotib joint, midtalar joints, calcaneus; looking for AVN, stress fractures
sustentaculum tali – top area of calcaneus, articulates with talus
Foot
Routine: AP/DP, lateral, oblique other: tangential
tuberosity of 5th metatarsal
Chest
views: PA, lateral
PA – puts heart close to film to look at size of heart review p. 48 notes
gastric air bubble = megenblas? anterior/retrosternal clear space posterior/retrocardial clear space – fills first costophrenic and costocardiac angles
normal: 10 ribs above right diaphragm
don’t see bronchi, bronchioles unless filled (bad)
ROENTGENOMETRICS
Measurements need to be performed accurately and correlated clinically
Major Errors of Mensuration
image unsharpness projectional geometric distortion patient positioning anatomic variations locating standard reference points observer error
Enlarged Sella Turcica
normal max: 16 x 22 mm (width by depth) at focal film distance (FFD) or 40” roof measured from anterior to posterior clinoids If enlarged, could be: - empty sell syndrome - tumor - normal variant - aneurysm Consider: - history - old xrays to rule out normal variant - MR to show tumor vs. empty space
Empty Sella Syndrome
hole in diaphragma sells lets CSF flow in, erodes pituitary
Clivus
= opposing part of sphenoid, from foramen magnum to dorsum sellae
Martins Basilar Angle
drawn from nasion (junction of frontal and nasal bones) to center of sella to basion (anterior margin of foramen magnum; follow ADI up)
normal 137-152 degrees
>152 = platybasia caused by:
- congenital maldevelopment of sphenoid and/or occipital bones
- bone-softening diseases such as Paget’s and osteomalacia
Chamberlain’s Line
hard palate to opisthion (posterior margin of foramen magnum; where internal and external lamina of skull meet; in line with spinolaminar junction)
odontoid should not extend more than 7mm above this line detects basilar invagination or basilar impression
McGregor’s Line
hard palate to inferior occiput
more accurate and easier to reproduce than Chamberlain’s odontoid should not extend above this line by 8-10mm
Basilar Impression
congenital
can be occipitalization
Basilar Invagination
patological can be caused by: - Paget’s disease - osteomalacia - fibrous dysplasia - arthritide such as rhematoid arthritis
George’s Lines
to detect alignment in sagittal plane (anterior or posterior displacement) along posterior vertebral bodies
Spinolaminar Line
to detect alignment in sagittal plane connecting spinolaminar lines
Anterolisthesis/Retrolisthesis
must be due to one of these:
- fracture
- dislocation
- ligamentous laxity (seen on fl/ext)
- degenerative disease
- anatomic reason
- physiologic reason
Retrolisthesis
posterior subluxation/displacement/dislocation/translation
consider drawing George’s lines and compare vert above to vert below—
upper one posterior to one below possibilities:
- trauma
- anatomic such as pedicogenic retrolisthesis (eg, short pedicle)
- physiologic
- degenerative disc disease
[If not due to any other cause, then always degenerative disc.]
Anterolisthesis
anterior subluxation/displacement/translation/dislocation = spondylolisthesis in lumbars due to: - pars defects (anatomic) - short posterior arch (anatomic) - trauma - physiologic - degenerative: posterior joint arthrosis
Atlantodental Interval
measured at smallest point between posterior surfaceof the anterior tubercle and anterior surface of the odontoid (usually inferior aspect)
checks integrity of transverse ligament Normal upper limit:
- Adult 3mm or 2.5mm
- Child 5mm or 4.5mm Etiologies of large ADI:
- trauma (rare, more likely to break odontoid than damage transverse ligament)
- inflammatory arthropathies
- Down Syndrome – 20% born with weird transverse ligament
- upper cervical anomalies such as occipitalization, agenesis of
posterior arch of C1
take flexion/extension – if moving, need neuro consult (may fixate) Rheumatoid arthritis is most common reason for big ADI
Antlantoaxial “Overhang” Sign
lateral margin of lateral masses of atlas extend lateral to superior articular processes of axis
bilateral displacement suggests fracture of atlas or odontoid process [Jefferson’s fracture = bilateral atlas fx]
unilateral offset can mean head tilt
mild overhand is a normal variant especially in children because of
different growth rates of the bones
Cervical Lordosis
- measure angle between C1 plane line and inferior C7 normal: 35-45
hard palate should be level with floor when taking xray >45 = hyperlordosis
Ruth Jackson Stress Lines
to show aberrant motion – but not specific done on fl/ext films
lines:
- extending and intersecting from posterior aspects of C2 and C7
- at C5/C6 on flexion
- at C4/C5 on extension
Cervical Gravitational Line
gross measurement of stresses
line from odontoid tip straight down
normal: line traverses anterior-superior aspect of C7
anterior weight bearing = line anterior to C7 body; more stress on discs? posterior weight bearing – more stress on facets?
Sagittal Canal Measurement
anterior line: along posterior vertebral body posterior line: along spinolaminar line normal: >16mm
Pre-vertebral Soft Tissue Space
- Retropharyngeal Interval/Space (RPI) – anterior of C2 body to back of trachea
Thoracic Spine Kyphosis
lines along superior endplate of T1, inferior endplate of T12 vertical perpendicular lines, angle of intersection measured Average: 30o
Normal upper limit:
56 in women
66 in men
Lumbar Spine Lordosis
lines drawn along superior endplate of L1 and base of sacrum vertical perp lines, angle of intersection
Average: 50-60, highly variable
Lumbar Gravity Line
line from mid portion of L3
intersects anterior 1/3 of sacrum
anterior to this is anterior weight bearing (stresses discs) posterior to this is posterior weight bearing (stresses facets)
Ferguson’s Angle/Lumbosacral Angle
worthless (NBQ) normal: 26-57
Meyerdings Method
of measuring spondylolisthesis (anterior subluxation of lumbars)
divide base of sacrum into 4
Grade I is 25%, assume bilateral pars defect
Grade II
Ullman’s Line
to detect spondylolisthesis (one above anterior to one below)
worthless
L5 vert crosses line perpendicular to base of sacrum, may have spondylo
Cobb’s Method
THE method to measure scolisis
angle between superior plate of vert at top of curve and inferior plate of vert at bottom of curve
use same verts for subsequent measurements
Tear Drop Distance
measurement of medial hip joint space
from Kohler’s teardrop to femoral metaphysis normal: 9-11mm
>2mm variance from contralateral side is abnormal must be correlated clinically (it works when it works) causes:
- trauma
- infection
- inflammation: Legg-Calve-Perthes (avascular necrosis of femoral
head) or joint disease
Kline’s Line
drawn across outer border of femoral neck
subtends the outer aspect of the femoral head
typically drawn on a child
line should cross femoral head or femoral capital epiphysis evaluates SCFE: Slipped Capital Femoral Epiphysis
tends to be bilateral in overweight male adolescents, requires surgery
Shenton Line
normal: smooth curving line along superior pubic ramus and medial aspect of femoral neck abnormal in: - hip dislocation - femur fx - SCFE
Kohler’s Line
from medial pelvic rim to external margin of obturator foramen acetabulum should not extend beyond this line acetabular protrusion caused by: - joint disease - Paget’s disease - bone softening disease - idiopathic
Boehler’s Angle
angle between lines drawn along superior margin of calcaneus normal: 28-40o
average: 30-35o
Acromiohumeral Space
measured from bottom of acromion to top of humeral head average: 10mm
narrowing is associated with supraspinatus tendinopathy = shoulder
impingement syndrome; humerus is elevated
CONGENITAL ANOMALIES
If you see one, look for others.
Hypoplasia
underdevelopment
Hyperplasia
overdevelopment
Aplasia
absence of development
Hypertrophy
pathological increased size
Hyperplasia
developmental increased size (congenital)
Primary Ossification Centers
present before birth one for centrum
2 for neural arches
Secondary Ossificaiton Centers
present after birth
epiphysis – forms articular cartilage; gives length to bone
apophysis – forms attachment site (bump) for attachment for ligaments
and tendons
Occipitalization of Atlas
occiput and atlas are fused partially or completely look for space between occ and atlas
rule out head tilt
- typically, anterior arch of atlas is fused to skull base
- 50% also have vert fusion at C2/C3
- basilar impression uncommon, although odontoid process is high
and directly beneath foramen magnum
- lack of segmentation and separation of the caudal occipital
sclerotome
normal variant, asymptomatic in most look for hypermobility at the ADI fl/ext needed to assure diagnosis
Agenesis of Posterior Arch
Normally, 2o ossification center for posterior tubercle develops in 2nd year of life
Basic defect is due to lack of cartilage template
can have partial or complete absence
enlarged C2 spinous is common
may see hypertrophy of anterior tubercle from long term altered
biomechanics
fl/ext needed
Failure of Fusion of C1 Posterior Arch
= spina bifida occulta, dysraphis, rachischisis Clinical Data:
- defective ossification of car template and failure of 2o growth ctr
- composed of cartilage and fibrous tissue no clinical significance or risk
Differential (other possibilities):
- none (too smooth to be fracture; no relevant trauma) Imaging
- see cleft or complete absence
- absence of psinolaminar lineon lateral
- hyperplastic anterior arch
Failure of Fusion of Anterior arch of C1
very rare
Chiari Malformation
herniation of cerebellar tonsils more than the normal variant of 3mm or less
associated with wrong way (left thoracic) scoliosis, bony anomalies, and syrinx/syringomyelia
seen on MRI Pathophysiologic Mechanisms
- underdevelopment of occipital somites to produce small, overcrowded posterior cranial fossa; tonsillar herniation occurs secondarily
- altered CSF dynamics characterized by systolic and diastolic CSF displacements related to phases of cardiac cycle; CSF flow also affected by respiration
- CSF flow reduced by herniation, can become plugged at foramen magnum
“Wrong Way” Scoliosis
= left convex scoliosis thoracic spine (lateral thoracic curves almost always go right)
potential of developmental/pathological changes of the spinal cord such as:
- syringomyelia
- Arnold Chiari malformation
- tumor
need neurological exam Imaging:
- MRI on adults with neurological symptoms
- MRI on all children
Syringomyelia
syrinx = spinal cord cavity Etiology: - pressure - tumor - congenital - Arnold Chiari – secondary to pathologic CSF dynamics; exaggerated pulsatile systolic wave in the spinal subarachnoid space drives CSF through anatomically continuous perivascular and interstitial spaces into the central canal of the spinal cord Imaging: MRI Associated Osseous Anomalies: - platybasia, basilar invagination in 25-50% - atlantooccipital assimilation 1-5% - Klippel-Feil syndrom 5-10% - incomplete ossification of C1 ring 5% - spina bifida C1 level - retroflexed odontoid process 26% - scoliosis 42% - kyphosis - increased cervical lordosis - cervical ribs - fused thoracic ribs - segmentation anomalies
Posterior Ponticle
= ponticulus ponticus, posticus ponticus, Kimmerly anomaly
forms the arcuate foramen
caused by ossification of atlantooccipital ligament because of aberrant 2o
growth center in the aol Clinical Data
- contains vertebral artery and 1st cervical nerve
- 14% of anatomic specimens (15% of population) Significance:
- minimal sig or risk
- question of vertebral artery occlusion (may be associated with
CVA but probably not); do George’s test (not reliable) DDx – do not confuse with mastoid process
Epitransverse Process
bony extension originating from the transverse processof C1 to end at the skull base (vs paracondylar process which originates from skull and goes down)
Significance:
- may create lateral head tilt
- may affect adjusting technique as C1 is effective fused to occiput
Imaging
- difficult on conventional radiography
- accessory joint may be seen on occasion
- rarely required tomography
Os Terminale
failure of union of 2o center of ossificaiton found at the tip of the dens (after age 12)
not associated with instability
DDx: fracture doesn’t happen at tip of odontoid
Os Odontoideum
lack of fusion of odontoid process with body of C2
could be previous fracture of odontoid synchondrosis that did not unite
upon healing
May be associated with
- Down’s Syndrome
- Klippel-Feil syndrome
- molding and hypertrophy of anterior tubercle – posterior edge
of anterior tubercle becomes convex instead of flat or concave (rounded) and large; implies long term improper articulation with the dens
Significance
- renders transverse atlantal ligament incompetent
- potential for significant neurological insult from trival trauma
- high velocity adjusting contraindicated
- neurological consultation
- fl/ext
[Most odontoid fractures do not unite in healing. Therefore most os odontoideum are, in fact, old ununited odontoid fractures.]
DDx – fracture? smooth cortices
neurological symptoms vary – may have one transitory episode of diffuse
paresis following trauma or progressive myelopathy with weakness
and ataxia
gait ataxia, syncope, vertigo, visual disturbances, cerebellar and
brainstem infarcts, seizures, sudden death (rare) indications for surgery:
- significant motionon plain radiography
- neurologic or neurovascular involvement
- persistent disabling pain despite appropriate nonoperative
management Imaging
- well-corticated separate ossicle, may be absent or difficult to see
- C1 subluxation
- short odontoid
- hypertrophic C1 anterior arch
Additional Studies:
- fl/ext to evaluate instability
- MRI to evaluate cord compression/contusion
Posterior Translation of C1 can be caused by:
1. long posterior arch
- fracture of posterior arch
- fracture of odontoid
- os odontoideum
radiculopathy
= pathetic change of nerve roots
myelopathy
= pathetic change of spinal cord
Ankylosis
= pathological fusion of 2 bones
Synostosis
= congenital fusion of 2 bones
Surgical arthrodesis
= surgical fixation of 2 bones
Block Segmentation
(synostosis)
= Block Vertebra = congenital nonsegmentation failure of somite segmentation
most common at C5/C6, C2/C3, L4/L5 Significance
- minimal clinical significance or risk
- may create aberrant segmental motion above and below the
fusion site DDx:
- surgical fusion
- pathological fusion – juvenile chronic arthritis, infection Imaging:
- rudimentary disc sometimes with calcification
- maintenance of vertebral body height
- smooth, often concave anterior vertebral body margins
- Wasp vert = dec AP dimension at level of disc
- well-formed foramen on lateral projection
- no osteophytes, surgery evident
need fl/ext to evaluate adjacent segmental motion – typical progression:
- loss of a motion unit
- hypermobility of those above and below
- degenerative disc disease
- hypomobility
- hypermobility of above and below
Kippel Feil Syndrome
= multiple block vertebra
complex of congenital anomalies that includes
- multiple segmentation anomalies of the cervical spine
- triad of:
. short webbed neck
. low hairline
. decreased rane of motion
associated with
- renal anomalies 50%
- deafness 30%
- spinal cord anomalies (syringomyelia, Arnold Chiari
- Sprengel’s deformity 25-40% - high scapula
Imaging
- fusion of vertebral bodies and posterior elements
- hemivertebrae
- scoliosis
- rib fusion
- Sprengel deformity
Anomalies found! carefully assess craniocervical junction; fl/ext indicated, rule out involvement of heart
Additional studies:
- fl/ext
- ultrasound to see 2 functioning kidneys
- intravenous urogram
- neurological evaluation
- MRI
Sprengels Deformity
congenital elevation of scapula incomplete descent of scapula
seenin 20-25% of cases of Klippel Feil females>males
usually unilateral
Omovertebral Bone
from neural arch to scapula
Down Syndrome
trisomy 21
20% of patients demonstrate laxity of the transverse altlantal ligament
flattened nose, wide spaced eyes, mental retardation
Cervical Ribs
extra rib that articulates with the transverse process principally at C7, rarely C5 and C6
look for articulation with downward pointing transverse process (C7) 2:1 females
Significance:
- thoracic outlet syndrome with neurovascular compression even with small ribs
- symptoms become more common in older population
- evaluate for peripheral vascular and neurological compromise DDx
- differentiate from an enlarged C7 transverse process (has articulation)
- can be palpated and confused with an enlarged lymph node Additional Studies
- thoracic outlet syndrome
- clinical examinations
- neurovascular studies
Transverse Process Hyperplasia
transverse process at C7 longer than T1
Butterfly Vertebra
failure of fusion of lateral halves secondary to persistence of notochordal tissue
widened vertebral body with butterfly configuration on AP view adaptation of vertebral endplates of adjacent vertebral bodies most common in thoracic and lumbar spine
usually insignificant – aberrant segmental motion probable Imaging:
- pronounced indentation of the endplates
- widening of the distance between the pedicles
- disk hypoplasia adjacently or possible fusion
Hemivertebra
vertebral body develops from two lateral ossification centers with a failure of growth occurring to form the hemivertebra
lateral hemivertebra most common structural scoliosis
Significance:
scoliosis
aberrant segmental motion inclusive of fusion associated with other congenital anomalies may see extra ribs
– compression fracture
- - - -
DDx Two
2 hemivertebrae on opposite sides, scoliosis may be slight
Segmented hemivertebrae will progress more than nonsegmented hemivertebra.
Schmorls Nodes
nucleus pulposus herniates through vertebral end plates very common can have back pain Imaging: - well-defined defect involving the endplate - giant Schmorl’s nodes: . disc space narrowing . degenerative disc disease . morphological vertebral body changes . decreased signal on MR . associated with Scheuermann’s disease
Scheuermann’s Disease
=juvenile discogenic disease
multiple Schmorl’s nodes with decreased vertebral body height
Limbus Vertebra
herniation of nucleus pulposus through secondary growth centers through the ring apophysis usually an isolated anomaly common in lumbar spine Significance:
- can be associated with Scheuermann’s disease
DDx – not fracture: smooth corticated margins, lack of lcinical history,
vertebral body avulsion uncommon in lumbar spine, no decreasein
height, conforms to shape of body Imaging:
- free fragment at anterior, superior body margins
- well-corticated
Posterior Limbus
implies trauma
Transitional Vertebra
incomplete segmentation at transitional levels of the spine difficult to associate with back pain
spinal segments demonstrate characteristics of
1. sacralization: L5 fuses to sacrum
2. lumbarization: S1 becomes lumbar spine-like (L6)
Example: incomplete sacralization of L5 with unilateral accessory
articulation involving sacral ala on left Imaging:
- spatulated hyperplastic transverse process
- variable accessory joint formation
- occasional accessory joint degeneration
- hypoplastic disc
- accurate segment count must include T1
Intervertebral Disc Hypoplasia
common cause of narrowed disc space
especially common in young patients where degeneration is not likely
Iliolumbar Ligament Calcificaion/Ossification
slide p. 98
calcification is a result of altered biomechanics due to transitional
segmentation
Facet Tropism
= facet asymmetry
coronal and sagittal facets at one level commonly L5-S1
Significance
- clinical association variable
- no clear evidence of association with degenerative disc disease
or back pain
Transverse Process Accessory Joint
slide p. 98
Persistent Apophyses and Epiphyses
= ununited 2o growth center
extremely common
do not confuse with fracture: look for smoothness, cortication, use the
history, learn where they occur (transverse processes, spinous processes, ring apophyses, trochanters)
Persistent Apophysis of the Ulna
slide p. 99
Os Acetabuli
slide p. 99
Oppenheimers Ossicles
ununited 2o growth centers of inferior articular processes of lumbar spine
Congenital Absence of Pedicles
more common in lumbars
“one-eyed pedicle sign” or
“blind owl sign”
anomalous formation of the neural arch creates enlargement of the
opposite neural arch (pedicle sclerosis) DDx:
- one-eyed pedicle sign and blind owl sign are most commonly caused by lytic metastasis (look for enlargement of opposite neural arch for agenesis)
- may require CT/MRI confirmation
Hahns Groove/Fissure
remnant of embryonic vasculature no significance
Congenital Hip Dysplasia
= Developmental Dysplasia of the Hip
displacement of the hip with acetabular dysplasia
etiology related to hip joint laxity and inverted labrum (starts as a soft
tissue problem)
more common in girls
more common in left hip
gives positive Ortolanis/Barlows test Significance
- must be a newborn diagnosis
- delayed diagnosis results in early osteoarthritis Imaging: Putti’s Triad
- absent of small proximal femoral epiphysis
- lateral displacement of femur
- increased inclination of acetabluar roof
Roentgenometrics:
- Y cartilage angle normal 12-29o
. 29 in hip dysplasia
Acetabular Protrusion
can be developmental or pathological (joint disease, bone-softening) use Kohler’s Line
Femoral Herniation Pits
in femoral neck
very common (could be normal)
no significance
result of mechanical stress from hip capsule and related musculature on
superolateral quadrant of femoral
fibrocartilaginous elements may penetrate tiny defects in the
degenerative cortex
Pubic Synchondrosis
variant ofmaturation
point of fusion between the ischium and pubis no significance
DDx – tumor, fracture
Vascular Groove
normal variant
impression from vascular pulsation no significance
see slide p. 102
Paraglenoid Sulcus
normal variant
vascular groove
female pelvis almost exclusively
Carpal Coalition
fusion of carpal bones
lunate to triquetrum mostcommon
may be associated with other congenital anomalies
Negative Ulnar Variance
relative shortness of ulna compared to radius, measured by comparing distal ends ot each bone
normal variant, no significance
Nutrient Canal
nutrient artery sometimes appears as an oblique radiolucent defect of ulna
Supracondylar Process
exostosis at anterior and distal humerus
points toward elbow
Struthers ligament at the distal aspect may be present Significance
- may fracture
- compression of median nerve and vascular structures
DDx – osteochondroma – benign tumor that looks the same, but points
away from elbow joint
Bipartite Patella
incomplete unification of multiple ossification centers 80% bilateral
fragment at the superior, lateral margin
smooth and well-corticated
may be subject to trauma
Fabella
sesamoid in lateral head of gastrocnemius
Growth Arrest Lines
any bone
normal variant, no significance
DDx – stress fracture (too well-defined, lack of history
Accessory Ossicles of the Foot
os trigonum – betw calcaneus, talus os tibiale externum – off navicular os supranaviculare
os peroneum -
os intermetatarseum and many more
Tarsal Coalition
talocalcaneal synostosis – fibrous or osseous conjunction between tarsal bones
talo-navicular
talo-calcaneal
talar beak associated – sticks up out of talus very common
loss of the subtalar joint
best imaged on CT (MR)
affects biomechanics, pain, spastic flat foot
Soft Tissue Calcification
- dystrophic – tissue trauma or infection, bleeding attracts Ca
- metabolic/metastatic - widespread (metastatic) soft tissue
calcification can occur secondary to metabolie and endocrinological
diseases (hyperparathyroidism) - physiological – normal,usually within cartilaginous tissue
Thyroid Cartilage Stylohyoideus Ossification
physiological – anatomical variation Significance:
- minimal clinical impact
- chiropractic precautions?
- Eagle syndrome – neck pain, rare
Imaging
- extends from styloid process at base of skull to hyoid bone
- may be segmented
Costal Cartilage Calcification
physiological
Falx Cerebri Calcification
physiological
calcification of the dura
no significance if midline
Petroclinoid “Ligament” Calicification
physiological
calcification of dura
no significance
Pineal Gland Calcification
physiological
50% of population
no significance if 10mm could be pinealoma
Phloboliths
dystrophic
calcified venous thrombi
perirectal veins
normal, no significance if parallel pelvic brim
Lymph Node Calcification
dystrophic lymph node injured, attracts Ca
amorphous globular calcification
common cause: tuberculosis (granulomatous)
Diabetic Calcification
metabolic
calcification of small vessels
Vas Deferens Calcification
dystrophic
seen in diabetics
no significance
associated vascular disease
Prostate Calcification
dystrophic
Track-Like Calcification
calcification of carotid artery
potential cerebrovascular ischemia
Calcification of Abdominal Aorta
not significant if over 40
Pectus Excavatum
depressed sternum
funnel chest
Pectus Carinatum
bird chest
3 Granulomatous Infections
tuberculosis
histoplasmosis
coccidioidomycosis
SCOLIOSIS
lateral deviation >15o and rotation of the spine, often associated with thoracic hypokyphosis
severe disease distorts the chest wall enough to restrict pulmonary and cardiovascular function
cosmetic deformity
named by side of convexity
Can be functional (soft tissue involved) or structural (fixed and fails to
correct on recumbent lateral bending radiographs due to bone shape)
Structural/Progressive Scoliosis
- idiopathic
- arthritic
- congenital
- neuromuscular
- tumors
- post-irradiation
Idiopathic Scoliosis
most common 85%
thought to be related to defects in proprioception and vibratory sense girls more often affected than boys (7:1) and disease is more likely to
progress and require treatment
patterns may be thoracic, thoraco-lumbar, lumbar, double major
Age Classifications for Scoliosis
Infantile – uncommon, must rule out congenital cause esp if left thoracic curve (need MR to look for tumor); M>F
Juvenile – 3-10 years F>M
Adolescent - >10 years old; most common, F>M
Etiology of Scoliosis
must be determined in each case since prognosis and etiology are highly dependent on etiology
Functional Scoliosis
non-progressive
muscle spasm
antalgia
may become structural if not corrected
Radiographic Assessment of Scoliosis
done to:
determine or rule out various etiologies
evaluate curvature size, site and flexibility
assess the skeletal maturity (progression happens before maturity) monitor curvature progression or regression
Tumors and Scoliosis
osteoid osteoma – most common tumor that causes painful scoliosis usually located in posterior elements
scoliosis is long, with concavity on the side of the lesion bone scan and CT required
Congenital Scoliosis
secondary to skeletal anomalies
can be hemivertebrae, congenital fusion
typically a short segmented C curve
bracing is ineffective; progressing curves must be surgically fused early
Neuromuscular Scoliosis
Etiology may be: - cerebral palsy - syrinx - poliomyelitis - muscular dystrophy - spinal cord tumor curves are othe long, single C curves idiopathic scoliosis with early onset (
Wrong Way Scoliosis
= Left convex scoliosis thoracic spine Significance:
- syringomyelia
- ArnoldChiari malformation
- neurology examination
Imaging
- MRI on adults with neurological symptoms
- MRI on all children
Neurofibromatosis
NF I and NF II
autosomal dominant with skin, endocrine, nervous system, and bone
manifestations
café au lait spots appear prior to age 3
skin nodules in late adolescence
scoliosis is a common abnormality
dysplastic vertebral bodies form and short, angular, usually high thoracic
curve
associated ribbon-shaped ribs and posterior vertebral body scalloping
due to expansion of dura
These curves can collapse rapidly and produce paralysis fibrosum molluscum
Radiation Therapy
If entire vertebral body of a skeletally immature patient is not included ina radition port, growth in the irradiated portion stops, with resultant scoliosis
Roentgenometrics for Scoliosis
Cobb’s Method – the preferred method
on AP radiographs
identify uppermost and lowermost involved vertebra of the curve that tilt
significantly toward the concavity and draw a line through the
endpltes
perpendicular lines to first two, measure intersecting angle
[use same verts for subsequent xrays]
Multiple curves may be present, measure each curve independently
Flexibility of Curvatures
Lateral bending radiographs evaluate flexibility of the curve
helps in determination of primary versus compensatory curvatures Compensatory curves usually correct with lateral bending
Rotation Estimates
Pedicle Method by Nash and Moe – most popular pedicle movement on the convex side is graded 0-4 0 normal 1 one pedicle disappearing 2 one pedicle not seen 3 one pedicle at midline 4 one pedicle past midline
Risser’s Sign
using the iliac apophyses to grade skeletal maturation
0-4 measure excursion of the apophysis over the extent of the crest 5 fused (no progression likely) takes 2-3 years to fuse
boys capping at 16
girls at 14
Greulich and Pyle
more accurate than Rissers
look at 2o growth centers for phalanges, carpals approx age = # carpals-1 (up to age 6)
Skeletal Maturity
predicts potential for pregression/correction
immature spine may be xrayed every 3-6 months (as needed)
5 degrees or more progression in 3 months time or less requires
orthopedic consultation
Monitoring Progression
initial films should be good quality AP/lateral erect films, in order to evaluate for intrinsic vertebral abnormalities
subsequent films can be lower quality and taken PA, using filters to protect reproductive tissue
gonad and breast shields required collimation essential
