How advancing technology is continuing to transform modern neurosurgery

Neurosurgery, which encompasses surgeries of the brain, spine, and peripheral nerves, has evolved dramatically over the past century due to rapid progress in imaging, navigation, robotics, and computational power.

While neurosurgeons have tools that allow them to perform safer, more precise, and less invasive procedures than ever before, it wasn't always like that.

Warren Boling, MD, Chair of Neurosurgery at Loma Linda University Health, explains how modern neurosurgery has become one of the most technologically driven fields in all medicine through years of medical innovation.

The foundations: how imaging changed everything

Early neurosurgeons had only crude imaging tools to approximate where abnormalities in the brain might lie. One of the first major breakthroughs came in the early 20th century with the pneumoencephalogram -- a procedure where air was injected into the spinal fluid with a lumbar puncture, which would create a negative contrast effect on skull X-ray to outline the brain and visualize surface abnormalities.

Another pivotal development came from a Portuguese neurologist who discovered cerebral angiography in the 1920s-- injecting contrast dye into the carotid artery to see shifts in blood vessels caused by tumors or stroke on a skull X-ray.

For many decades, these tools were the only imaging modalities available for the brain, with angiography still an important tool used in modern medicine.

CT and MRI: precision when it truly matters

Technology took a dramatic leap for neurosurgery with the inventions of the CT scan and the MRI.

The invention of the CT scan in the 1970s by the British company EMI used X-rays combined with early generation computers that had integrated recent advances in silicon chip and microprocessor technology to generate cross-sectional images of the brain.

"The CT became the dominant imaging modality due to its ability to visualize deep brain structures, becoming a staple in diagnosing trauma, stroke, and tumors," Boling said.

CT remains today an important tool, particularly because of its ability to quickly acquire images to diagnose many common brain and spine problems.

In the 1970s, the first MRI scanners were developed and became commercially available in the 1980s. The MRI uses powerful magnets and resonance frequencies to detect subtle changes in tissue intensity, which requires advanced computer software and hardware to interpret the signals.

"MRI allows clinicians to distinguish gray matter from white matter, view fluid-filled spaces, detect edema, and identify tumors and developmental abnormalities with exceptional clarity," Boling explains.

Another advantage of MRI is that it avoids the radiation exposure inherent in CT imaging.

"Modern scanners, including today's high magnet strength 3-tesla (3T) machines, offer extraordinarily high-resolution images that guide nearly every major neurosurgical procedure," Boling says.

However, the powerful magnets require special rooms to be constructed to house the machines, and considerable precautions are taken to prevent metallic objects from entering the MRI space. Due to the expense and complexity of MRI, CT scan remains the most readily available and utilitarian option for brain and spine imaging.

With the modern sophistication of CT and MRI imaging, the next advance was integrating imaging directly into the operating room. Surgeons can now perform real-time scans during procedures, adjusting their approach immediately based on what the images reveal.

Neuronavigation: neurosurgery's GPS system

Introduced in the 1990s, neuronavigation is an essential tool for brain and spine surgery. Before its development, neurosurgeons relied on their interpretation of static images and anatomical intuition, sometimes requiring large craniotomies simply to locate a small tumor.

"Neuronavigation works by creating a precise 3D digital model of the patient's brain or spine based on fine-cut MRI or CT images," Boling says.

The 3D model is then aligned with the patient's actual position in the operating room. Using infrared cameras or magnets combined with a tracked pointer - similar to the triangulation system used by GPS satellites to locate your car on the earth's surface - neurosurgeons can pinpoint even the smallest lesion with millimeter accuracy. Neuronavigation also allows: