History of Imaging of the Nervous System in Children

Technological Development

• Indirect imaging prior to CT and MRI: Prior to the advent of CT and MRI, brain imaging relied on radiographic techniques. The brain is not directly visible on radiographs, so various forms of introduced contrast were required. For example, in pneumoencephalography, air was introduced into the cerebrospinal fluid to highlight ventricular and cisternal anatomy.
• 1920s – Cerebral angiography: Cerebral angiography, obtained through the intra-arterial injection of radiodense contrast agents, was introduced by Egas Moniz in 1927 (9). Angiography allowed demonstration of intracranial vascular anatomy, but evaluation of the brain parenchyma remained indirect.
• 1970s – CT: The advent of CT imaging in the 1970s allowed direct imaging of the brain parenchyma and revolutionized diagnosis of many neurosurgical and neurological conditions (1,2). Progressive improvements in CT technology have followed, including multidetector scanners and helical acquisition. These improvements allow extremely rapid CT acquisition at high spatial resolution.
• 1980s – MRI: The introduction of clinical MRI in the early 1980s brought improved soft-tissue contrast, compared with CT, and allowed imaging in multiple planes (3,4) . MRI technology continued to advance through the 1990s and 2000s with the introduction of high-field scanners and novel imaging contrasts (diffusion imaging and blood oxygenation level–dependent (BOLD) functional imaging, for example).