4 - Imaging of the nervous system

Summary

Outcome research in neuroradiology is focused on two mainstays: diagnostic and interventional neuroradiology. The objective of diagnostic neuroradiology is to establish an accurate diagnosis and reveal criteria with respect to prognosis and optimal patient treatment. Adequate and rational utilization of the ‘instrumentarium’ of imaging techniques is mandatory. This has witnessed a dramatic change since the development of ventriculography and pneumencephalography in 1918–19 by W. E. Dandy, the introduction of myelography in 1922 by Sicard and the advent of cerebral angiography in 1927 by E. Moniz (Taveras 1990). However, the introduction of computed tomography (CT) and magnetic resonance imaging (MRI) have exerted the greatest impact on the development of neuroradiology as a specialty within the ‘neurosciences’ (Bucci 1991). The use of ionizing radiation by CT, myelography, angiography on the one hand, and the use of ultrasound and radiowaves of particular frequency by Doppler sonography and MRI respectively, result in differing diagnostic capabilities available for a broad spectrum of physiological and pathological conditions. PET, magnetic resonance angiography and functional imaging, and Doppler sonography, have extended the information provided from a mere morphological to a functional level. With interventional neuroradiology a rapidly developing specialty is providing a therapeutic alternative to surgery in many vascular pathologies. Tables 4.1–4.7 conceptualize our experience by attributing a specific diagnostic modality to the most frequent pathologies. Taking into account that access to hardware and software even among university hospitals differs, the potential of the currently used imaging devices is discussed with particular emphasis on criteria affecting patient prognosis and improving our ability to forecast outcomes.