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A.

B.

Coronal T2 FLAIR image demonstrates

high signal glioma in left temporal lobe.

C.

MRI is considered safe for patients, even at very high

field strengths (>3–4 T).

These provide a vascular flow map rather than the ana-

tomic map shown by conventional angiography.

spin echo MR images.

4-2G).

MRA can also be acquired during infusion of

contrast material.

Advantages include faster imaging

times (1–2 min vs.

10 min), fewer flow-related arti-

facts, and higher-resolution images.

Recently, con-

trast-enhanced MRA has become the standard for

extracranial vascular MRA.

Proper technique and timing

of acquisition relative to bolus arrival are critical for

success.

In rou-

tine spin echo imaging, images of the brain can be

obtained in 5–10 min.

Fast MRI reduces patient and

organ motion, permitting diffusion imaging and tractog-

raphy (Figs.

4-2H, 4-3, 4-4C, 4-6; and see Fig.

27-16),

perfusion imaging during contrast infusion, fMRI, and

kinematic motion studies.

4-3B).

4-6).

Irritated or infiltrated nerves will

demonstrate high signal on T2W imaging.

Multiple images of glucose uptake

activity are formed after 45–60 min.

A lower activity

of FDG in the parietal lobes has been associated with

Alzheimer’s disease.

FDG PET is used primarily for the

detection of extracranial metastatic disease.

In patients with a suspected spinal block, MR is the

preferred technique.

Adequate hydration before and

after myelography will reduce the incidence of this

complication.

Management of post–lumbar puncture headache is

discussed in Chap.

8.

Hearing loss is a rare complication of myelog-

raphy.

Intrathecal

contrast reactions are rare, but aseptic meningitis and

encephalopathy may occur.

Seizures occur follow-

ing myelography in 0.1–0.3% of patients.

CT and plain films are

obtained following the procedure.

Angiography has been replaced for many indications by

CT/CTA or MRI/MRA.

The most feared complication of cerebral angiography is

stroke.

35) prior to aortic aneurysm repair.

Many of these disorders place

the patient at high risk of cerebral hemorrhage, stroke,

or death.

Michael J.

The characteristics of the

normal EEG depend on the patient’s age and level of

arousal.

5-1 ) .

Digital systems are now widely used for recording

the EEG.

With generalized tonic-clonic sei-

zures, the EEG is always abnormal during the episode.

Thus,

the EEG cannot establish the diagnosis of epilepsy in

many cases.

5-2).

Normal EEG showing a posteriorly situated 9-Hz alpha

rhythm that attenuates with eye opening.

B.

Abnormal EEG

showing irregular diffuse slow activity in an obtunded patient

with encephalitis.

C.

D.

Periodic complexes occurring once

every second in a patient with Creutzfeldt-Jakob disease.

Hori-

zontal calibration: 1 s; vertical calibration: 200 μV in A, 300 μV

in other panels.

(From MJ Aminoff, ed: Electrodiagnosis in Clini-

cal Neurology, 5th ed.

A, earlobe; C, central; F, frontal; Fp, frontal polar; P, pari-

etal; T, temporal; O, occipital.

5-1).