csi by chenshu


									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
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
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
   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.
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
Helical CT =faster & greater sensitivity.
Use CT on all high risk pts and low-risk w/
  equivocal findings or incomplete visualization.

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

     More Sensitive?            Less sensitive?

     Cost effective/more        Less expensive?

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

National Emergency X-Radiography Study
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
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
 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
 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

   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
 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
 Determine proper alignment in instances
  where a pt moved during CT exam resulting
  in unclear image
 If don’t have good technology stick with
   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
   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
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!
   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:
   Daffner RH. Identifying patients at low risk for cervical spine injury: the
    Canadian C-spine rule for radiography. (editorial) JAMA 2001:286:1893-
   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

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