Brain imaging in the era of bell bottoms
Arrival of the CT scanner at Yale
“We are proposing that the Yale-New Haven Hospital acquire the EMI scanner, [which] represents the most revolutionary advance in neuroradiologic evaluation of patients. …” So begins the December 1973 letter from E. Leon Kier, M.D., HS ’66, that would lead to Yale-New Haven Hospital’s acquisition of Connecticut’s first computed tomography (CT) scanner. The first-of-its-kind scanner that Kier refers to in the letter was named after the company where it was developed, the EMI record label, which also had an independent electrical and computer engineering arm. (Profits generated by the British label’s top artists—four young Liverpudlians named John, Paul, George, and Ringo—supported EMI’s investment in the CT machine.) Kier, then chief of neuroradiology, was writing to the chair of the diagnostic radiology department, Richard H. Greenspan, M.D., to convince him of the necessity of acquiring the new machine, which was first used on human patients in October 1971 in England.
In the early 1970s, there were two main methods for diagnosing patients with neurological problems: cerebral angiography and pneumoencephalography. The resulting images could tell a well-trained viewer what part of the brain was affected and whether the lesion in question was a tumor, vascular malformation, or hematoma (bleeding). “These procedures were time-consuming and risky for the patient and required hospitalization,” Kier says today.
If a patient came into the emergency room with a stroke, angiography would be performed: A catheter was inserted into a large artery and threaded from the neck to the carotid, where a contrast agent was injected. Radiographs taken while the contrast agent circulated would help identify the location of constriction or bleeding. During a pneumoencephalogram, oxygen was injected into the spinal subarachnoid space (a cavity filled with cerebrospinal fluid that contains the blood vessels that supply the brain and spinal cord), which permitted the visualization of the brain’s ventricular system and subarachnoid spaces on X-rays. Kier recalls that these procedures were dangerous for the patients if not done properly.
Compared to these methods, Kier says, CT was “a quantum jump. It was a revolutionary development, and we felt that we had to get the machine to move into a whole new phase of medical care.” The scanner that was acquired was actually the ACTA, a CT scanner developed at Georgetown University whose gantry size allowed imaging of the whole body, not just the head, as with the EMI scanner. There was a research scanner on campus as early as 1972, and this was used to image both healthy volunteers and patients with trauma. Because it wasn’t yet known whether CT images were sufficient or useful for diagnosis, these initial studies helped justify the clinical protocol and need for a dedicated CT scanner for patient care. By 1978, the CT facility at the hospital was open 24 hours a day, and by 1990, when Kier stepped down as chief of neuroradiology, there were four scanners.
Kier’s radiology technologist at the time, Cathy Camputaro, recounted the early CT scanning procedure. “Imaging the head from the bottom of the chin to the crown took an hour, or six minutes per image slice. Now the entire body can be done in 14 seconds.” Patients were sent away while computers reconstructed the images, which were then printed as Polaroids or on X-ray film. “When the first images came out, I was stunned that I could see the ventricles. It was incredible. There was no other way at that time to do neurological diagnoses except with cerebral angiography or pneumoencephalography.” Camputaro, who still manages 3-D CT and MR imaging at the hospital, says that not only did CT simplify image interpretation, but it also changed how anatomy and physiology are taught. Since almost all ER patients are automatically scanned, and those scans are available on the hospital server, students are now trained with CT images rather than with textbook images.
Summing up the sea change, Kier, who is still one of the hospital neuroradiologists, says, “We went from painful, dangerous procedures to painless and safe procedures. Of all the changes that the diagnosis of neurological disorders has gone through prior to the modern era of MRI scanning, the biggest change was at the time CT was introduced.”