Table 4. Ability of different techniques to identify and define pathology

Technique                     Identify                Define anatomic
                              physiologic insult      defect

History                          +                       +

Physical examination:            
  Circumference measurements     +                       +
  Reflexes                       ++                      ++
  Straight leg raising (SLR)     ++                      +
  Crossed SLR                    +++                     ++
  Motor                          ++                      ++
  Sensory                        ++                      ++

Laboratory studies               ++                      0
  (ESR, CBC, UA)
  Bone scan[1]                   +++                     ++
  EMG/SEP                        +++                     ++

X-ray[1]                         0                       +
CT[1]                            0                       ++++[2]
MRI                              0                       ++++[2]
Myelo-CT[1]                      0                       ++++[2]
Myelography[1]                   0                       ++++[2]

1  Risk of complications (radiation, infection, etc.): highest for
   myelo- CT, second highest for myelography, and relatively less risk
   for bone scan, x-ray, and CT.
2  False-positive diagnostic findings in up to 30 percent of people
   without symptoms at age 30.
Note: Number of plus signs indicates relative ability to identify or
define.