special studies Flashcards
what is an x-ray taken after a radio opaque substance is injected into subarachnoid space?
pyelography- high risk, less used
what is the common substance used in myelography?
metrizamide
what is CT better for?
bone
what is MRI better for?
neural tissue and bone marrow
what would you need to use with an obese patient who exceeds weight limits for CT and MRI?
pyelography
what is a common complication of a patient with MRI?
internal metal objects
what is a radiographic record after introduction of opaque material into a joint? not often used
arthrogram- MRI arthrography more common
what is a type of radio nucleotide imaging that involves intravenous injection of radioactive compounds known to adhere to metabolically active bone?
bone scan- gamma detectors localize regions of uptake
when is a bone scan used?
acute LBP where tumor, infection or occult fracture are suspected
when is bone scan contraindicated?
pregnancy and breastfeeding
what is ultrasound used for?
evaluation and location of space occupying soft tissue masses
what is doppler ultrasound used for?
location of some vascular venous occlusions
what is the study of electrical activity of muscles and associated muscle activity? involves placing needle electrodes into skeletal muscle and displayed on cathode ray oscilloscope and heard on the loud speaker?
EMG- electromyography
what information can be obtained from EMG?
electric activity from needle inserted into muscle
electric activity of resting muscle with needle undisturbed
electric activity of motor unit during voluntary contractions
what is used to evaluate the conductivity of a nerve from the point of stimulation to the muscle?
NVC- nerve conduction velocity
what NVC occurs in neuropathy?
conduction rates less than 40 m/s
what are normal NVC for median and ulnar nerves and common peroneal?
median and ulnar- 50-60 m/s
common peroneal- 45-50 m/s
When are electrophysiologic tests used?
patients with sciatica to evaluate spinal cord, nerve roots and peripheral nerves myelopathy radiculopathy neuropathy myopathy
what is used to assess acute and chronic nerve root dysfunction, myelopathy, myopathy?
EMG
what test measures sensory conduction through nerve roots and used for cervical and lumbar neuropathies?
H reflex
what test is for motor conduction through nerve roots, assess proximal neuropathies?
F wave response
what assesses acute and chronic recruitment patterns during static and dynamic pass using surface electrodes instead of needle insertion?
surface EMG
what assesses sensory neurons in peripheral and spinal cord pathways?
sensory evoked potentials
what is used to assess acute and chronic peripheral entrapment neuropathies that may mimic radiculopathies?
nerve conduction studies
when would you most likely use EMG/NCV?
LBP problems with confusing clinical picture or severe leg symptoms lasting more than 3-4 weeks
what info does EMG/NCV provide when using the tests?
1 presence or absence of radiculopathy or neuropathy as cause of sx
2 provide info on specific nerve roots that may be compromised
3 differentiate between acute and chronic nerve root dysfunction
what are SEPs most useful for?
assessing spinal stenosis and spinal cord myelopathy
SEP- sensory evoked potential
what is EEG used for?
measuring electrical activity of the brain
what is used for inter cranial aneurysms, vascular disorders, hematoma and tumors?
angiography
what is thermography used for?
measuring temp differences on each side of body
presence or absence of radiculopathy (NRC)
RSD
