Neuroimaging evaluation of patients with headaches.

As discussed in the introduction, the rote laboratory and neuroimaging evaluation of a patient with headache but without other neurologic symptoms or signs is often unrewarding. Such evaluations are dictated by the clinical history and examination, hence rely on the diagnostic acumen of the physician. In the case of patients during their initial visit, it is frequently useful to proceed with skull radiographs and, if the symptoms warrant, contrast-enhanced CT scanning. In the future, as NMR imaging becomes more widely available, it may prove useful for these initial clinical evaluations. More invasive procedures, such as angiography, are undertaken only if specific indications, such as those summarized in Table 1, are present.