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									Primary Screening for Cervical
         Spine Injury
  Which Screening Modality is better,
     Radiography or Helical CT?
         Paige Gerbic MS4
Cervical Spine Injuries

Every year 1million pt’s admitted to ED due
  to C-Spine injuries.
Spinal cord injury and paralysis are important
  health burdens in the U.S. with an annual
  incidence of 40/1million population.
Most cases = blunt force trauma
Missed C-Spine Injuries
  Devastating to patients – lead to paralysis
   and death
  Estimated to cost society $3.4 billion
   annually
Legal Implications

  If proper radiological exam not performed –
     indefensible in a court of law
  Radiologist can be liable for failing to
     recommend further studies even though they
     are not the examining clinician
  Missed unstable c-spine injuries lead to some of
     highest jury awards and monetary settlements
     in medical malpractice litigation
RADIOGRAPHY – current SOC
for primary c-spine screening

   Minimum standard           Supplementary views
    views                         Bilateral obliques

      Lateral through C7         Swimmer’s

      AP                         Flex ion and

      Odontoid                    extension
AP, Lateral, and OM

Flexion and Extension
RAO, swimmer’s, LAO

American College of Radiology
(ACR) 1995
   No c-spine radiography required for asymptomatic
    trauma pts.
   AP, lateral and open mouth views are adequate
   Swimmer’s view to examine C7 if necessary
   Flexion and extension if suspect ligamentous
    damage
   Oblique projections in specific cases
Usefulness of Radiography in c-
spine injuries
 Late 1980’s – Mirvis et al recommended the
  primary study be standard radiography
 The American College of Radiology
  endorsed this view
Usefulness of Rad Continued
Vandermark claimed:
Well positioned and optimally exposed
 radiographs disclose 95% of clinically
 significant C-spine fractures.
However – these high quality studies are often
 impossible to obtain and pt’s at highest risk
 are most likely to have technically
 compromised imaging.
CT scans

   Helical CT was recommended only when
    screening conventional radiographs raised
    the question of craniovertebral injury.
CT

Research
1996 Nunez et al 40% of Fx’s missed on rad later
  revealed on CT
1/3 had clinically significant or unstable Fx’s
1998 Nunez and Quencer – the ACR criteria needs
  reeval.
Helical CT =faster & greater sensitivity.
Use CT on all high risk pts and low-risk w/
  equivocal findings or incomplete visualization.
Caution

   Other researchers, Daffner and El-Khoury
    urged caution stating CT is expensive and
    unproven
So, which do you choose?
   Helical CT                 Conventional Rad
     Faster?                    Slower?

     More Sensitive?            Less sensitive?

     Cost effective/more        Less expensive?

      expensive?
Risk Stratification
Need risk stratification to get the most out of
  imaging modalities:

National Emergency X-Radiography Study
(U.S.)
Canadian C-spine Rule

Both used to identify low risk patients. The Canadian rule found to be
   superior in research.
National Emergency X-
Radiography Study (5 criteria)
 Absence of midline cervical tenderness
 Normal level of alertness
 No intoxication
 No focal neuro deficits
 No painful distracting injury
Patient with all of these findings needs no
  imaging of the C-spine - a low risk pt.
Canadian C-Spine Rule
   Any high risk factor mandating radiography? (Age
    >65 or dangerous mechanism or paresthesias in
    extremities. ) Yes = radiography
   Any low-risk factor that allows safe assessment of
    range of motion? No = radiography
   Able to rotate neck actively (45 degrees L and r)
    No = radiography
Dangerous mechanism definition
   fall from elevation >3ft or stairs; an axial
    load to head; an MVA at high speed >100
    KM /hr or with rollover or ejection; a
    collision with a motorized recreational
    vehicle; or a bicycle collision. A simple
    rear-end motor vehicle collision excludes
    being pushed into oncoming traffic, being
    hit by a bus or a large truck, a rollover, and
    being hit by a high-speed vehicle.
Time is of the Essence in Trauma
 C-spine injury assessment in the trauma has
  to be FAST
 Time is the enemy for trauma victims
 Trauma surgeons are ruled by the
“Golden Hour”
Radiography is SLOW
   Daffner research:
     On average 22minutes for a standard 6
      view study( AP, lat, OM, R&LAO, swim)
     79% of patients needed one or more
      studies redone!
     The atlantoaxial and swimmer’s view are
      the exams most frequently needing to be
      redone
CT is Faster        (Daffner)

   = 12 minutes for c-spine +concomitant
    cranial eval

   11 minutes for cervical exam only

   These are ½ the time of conventional rad!
CT is Sensitive
 CT picks up many of the clinically
  significant fractures that radiography does
  not. It is 98% sensitive for fracture
  detection
 It also picks up many insignificant fractures
  as well such as stable transverse and
  spinous process fractures
(Nunez et al)
“Insignificant” Findings on CT

   Reflect substantial absorbed energy

   May serve as markers for more severe
    ligamentous, disk, brachial plexus, and
    vertebral artery injuries - There is debate as
    to what to do with insignificant findings
CT is Cost Effective
   But it’s more expensive than radiography!
    How can it be cost effective?

   Blackmore et al performed a cost
    effectiveness study that risk stratified pts
    into low, mod, and high risk patients.
Blackmore et al Risk
stratification
 High (fracture risk of 11.2%) = severe head
  injury, focal neuro deficits, >50 yrs w/ high-
  energy mechanism of injury.
 Moderate (4.2%)= >50 yrs w/ a moderate-
  energy mechanism or <50 w/high energy.
 Low (2.1%)= <50 w/ moderate energy
  mechanism of injury.
Outcome measures
   Cost effectiveness was based on:
     Paralysis prevented, total cost of

      screening strategies, and incremental
      cost-effectiveness ratios
Blackmore study continued
 Blackmore et al found c- spine screening
  with CT is cost effective for High and
  Moderate risk patients
 Low risk pts should undergo radiography or
  no imaging
Blackmore et al’s Study
concluded CT screening:
   prevents cases of paralysis (3 high-
    risk and 8.5 moderate-risk in the
    hypothetical cohort)
   saves money for society
    ($55,000/quality adjusted life year in high
    risk patients)
Later research
 Hanson et al reaffirmed that patients with a
  greater than 5% risk of cervical spine
  fracture should undergo helical CT
 The diagnostic yield for unstable injuries
  determines the rate of avoidable neurologic
  deficits and thereby justifies CT
Blackmore et al’s
recommendation

   CT should be considered as
    THE PRIMARY cervical spine screening
    modality in selected victims of major
    trauma who are examined in high-volume
    urban ED’s.
Why continue to obtain
radiographs?
 Rybicki et al research
The lateral radiograph remains essential
and fundamental for assessing :
     prevertebral soft tissues
     vertebral alignment
     foreign bodies.
Other reasons for radiography
 Provides an overall “road map” to ID gross
  abnormalities
 Determine proper alignment in instances
  where a pt moved during CT exam resulting
  in unclear image
 If don’t have good technology stick with
  radiographs
OHSU
   In general radiologist agree CT can be the primary
    screen for high and moderate-risk pts
   Radiography first in low-risk and follow up with
    CT if indicated
   Try to get as much clinical data about the pt and
    that way you can make proper imaging
    recommendations
   Standard protocol, however is to use radiography
    as primary screen for c-spine injury
In Conclusion
   Primary CT screening for c-spine trauma
    v/s radiography:
     Is cost effective (when pts are risk stratified)
     Is time efficient (when done concomitantly
        with cranial CT)

       Is sensitive (more than conventional
        radiography)
Bottom Line
   No standard yet calls for replacing radiography
    with helical CT but some ER’s such as the U of
    Washington are doing just that.
   Studies prove helical CT as the primary screening
    exam of c-spine injuries is efficient for accuracy
    of diagnosis, is time and cost effective.
 Such     a standard is evolving!
References
   Berlin L. CT Versus Radiography for Initial Evaluation of Cervical Spine
    Trauma: What Is the Standard of Care? AJR 2003; 180: 911-915
   Blackmore CC, Ramsey SD, Mann FA, Deyo RA. Cervical spine screening
    with CT in trauma patients: a cost-effectiveness analysis. Radiology 1999;212:
    117-125
   Daffner RH. Identifying patients at low risk for cervical spine injury: the
    Canadian C-spine rule for radiography. (editorial) JAMA 2001:286:1893-
    1894.
   Daffner RH. Helical CT of the cervical spine for trauma patients. A time
    study. AJR 2001;177:677-679
   Daffner RH. Cervical radiography for trauma patients. A time-effective
    technique? AJR 2000;175:1309-1311
   Hanson JA, Blackmore CC, Mann FA, Wilson AJ. Cervical spine injury. AJR
    2000;174:713-717

								
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