The human central nervous system (CNS)—the brain and spinal cord—contains roughly 87 billion neurons: 86 billion in the brain and 1 billion in the spinal cord (give or take a few). It is the most complex system we know of.
Yet to treat conditions ranging from Parkinson’s disease to back pain, medical specialists must operate adjacent to and within the CNS to reach the affected area while minimizing damage to the surrounding nerves. So when new ways to visualize and navigate the CNS become available, you can be sure Torrance Memorial physicians—neurosurgeons, endovascular surgeons, interventional radiologists and other specialists—are keen to evaluate, understand and employ the capabilities they offer.
“There’s a lot to talk about in terms of advancements in neuroimaging,” says Paula Eboli, MD, Torrance Memorial medical director of neurosurgery and endovascular surgery. First, though, it’s important to understand what medical imaging means. It’s more than just the two-dimensional X-rays you might imagine.
Some medical imaging systems can create three-dimensional maps of the area to be operated on. Working together, medical imaging equipment and image processing software can overlay a 3D map created before surgery onto a video screen of the area being operated on in real time—during the procedure—guiding the surgeon with a precision that would have been unattainable just a few years ago.
The O-arm Surgical Imaging System is one such system. “It’s like an X-ray that spins 360 degrees so you can get 3D visualization,” explains Dr. Eboli. Imagine a large plastic donut standing on edge; that, essentially, is the O-arm.
The ring opens into a C shape to allow patients to be easily moved in and out of the donut hole, which is a little over 3 feet in diameter. The ring contains imaging equipment that can spin to create 2D fluoroscopy (a real-time X-ray “movie”) or 3D images.
“The O-arm can create virtual images that are then superimposed on the real image during a procedure,” explains Dr. Eboli. “This lets us see details that would otherwise be occluded.”
The O-arm Surgical Imaging System can be used in a variety of procedures including spine, cranial and orthopedics.
By enabling greater precision, the O-arm allows procedures to be less invasive, with smaller incisions and less impact on healthy tissue surrounding the area being treated—all of which leads to less pain and speedier recovery times.
“The O-arm has been in service for less than a year, but it’s proven technology,” Dr. Eboli says. “We use it primarily for spine surgery but also for deep-brain stimulation,” a procedure in which electrodes are placed at precise points in the brain to alleviate tremor.
The latest advances in medical imaging don’t have to revolve around equipment. Sometimes there’s an app for that, like Torrance Memorial’s RapidAI (actually an AI-enabled software suite that includes a mobile app). RapidAI is designed to help medical providers quickly diagnose and respond to strokes.
The software processes and analyzes CT images of suspected stroke patients, highlighting large blood vessel blockages within five minutes. The RapidAI app sends alerts and images to on-call physicians so they can make a diagnosis and respond, assembling a team and beginning treatment immediately.
“At Torrance Memorial, RapidAI is in widespread use for stroke,” says interventional radiologist George So, MD. “If a patient comes in with a large vessel that is occluded, we can go in and take it out. But we have to know that is what is going on and where the occlusion is.”
Dr. So continues: “When a patient comes to the hospital with a suspected stroke, the emergency department gets a CT scan. RapidAI analyzes the imagery and gives physicians information, including perfusion defect.” That is a region of reduced blood flow indicating an ongoing stroke.
These alerts “can get the whole team ready,” he points out. “The idea is to save time, and RapidAI saves hours. We use it every day, every hour.”
Like RapidAI, DaTscans also save time—in this case, when diagnosing Parkinson’s disease. “We’ll see a patient with a tremor that could be Parkinson’s or another movement disorder,” explains Dr. So. “Typically the doctor prescribes medication to see if it reduces the tremor. This can provide a diagnosis, but it takes time. Other diseases can mimic Parkinson’s; it’s a very difficult thing to diagnose, and the process can take months. DaTscans let us see if the brain has lost dopamine neurons, helping us make an early diagnosis without using medications.”
A DaTscan, or dopamine transporter scan, images an injected tracer drug that attaches to a molecule found on dopamine neurons. Parkinson’s patients typically have reduced dopamine neurons in specific areas of the brain.
“We order a lot of DaTscans now,” Dr. So says, “often one or two cases a day, and the rate is increasing as more and more people are diagnosed with movement disorder. Whatever the issue, with DaTscans and other imaging techniques, we have better tools to sort it out. We keep moving forward.”
