Among the imaging modalities commonly used in orthopedic surgery — radiography, CT, and MRI-the projection X-ray is still the most pervasive and essential examination. In Japan and elsewhere, the digitization of the X-ray exam is rapidly progressing with Fujifilm's FCR (Fuji Computed Radiography) boasting the largest installed base.
Koshigaya Hospital, which is a part of Dokkyo University's School of Medicine, is making good use of CR for accurate and rapid diagnoses. The basic policy of this hub hospital in Koshigaya City (Saitama Prefecture) is what it calls "joint medication," which calls for the use of PACS to join hospitals and clinics into an electronic network in the near future. At present, Koshigaya Hospital is in the process of digitizing and networking the data in its affiliated hospitals and clinics.
Masahiro Nakajima, a radiographer and pioneer in digital imaging in Japan, has first-hand experience with the installation of the FCR unit, which is primarily used in orthopedic surgery at Koshigaya Hospital.
One of the first problems the hospital encountered when planning for digital radiography was the small space of the X-ray room, Nakajima said. It was for this reason that planners didn't even consider installing an upright image reader, but opted instead for a compact cassette-type CR.
"When taking X-rays of the cervical vertebra, shots from six different angles are necessary. This means that a different cassette must be used for each angle, and this has to be repeated six times. This process was much too burdensome and time-consuming for us," Nakajima said. "Just as we were weighing these factors, we heard that Fujifilm was coming out with a compact, high-performance CR suitable for our requirement."
In September 2004, Fujifilm announced a new model of the FCR unit, the VELOCITY-U, that uses HD LineScan technology. The unit is the fastest FCR upright image reader and is an enhancement of its predecessor — the FCR5501 Plus. It is speedier, more compact, more functionally designed, and uses a new image processing technology. It also facilitates a more efficient on-site workflow, Nakajima said.
A maximum of 240 imaging plates per hour at 10-pixel resolution can be processed with the unit regardless of image size, thus realizing a speedy operation.
Operating hours at Koshigawa Hospital are 8:30 a.m. to 5 p.m. daily, during which an average of 400 people are imaged by CR. On average, two views per patient are taken, which creates a total of about 800 images a day. Mornings are devoted to outside patients and afternoons to hospitalized patients.
"After installing the VELOCITY-U, I was able to reduce processing time from 30 seconds to 9 seconds," Nakajima said. "Due to the speedy display time on the console, imaging retakes consume less time. This results in shorter waiting times for our patients."
Characteristics of the VELOCITY-U that make it easier to use are grids that can be easily removed on-site, and a center of the image that can be lowered to 47 cm from the ground, which enables the lower extremities to be X-rayed.
"Sometimes when I take an image of patients with an abnormality at the waist, I have to make them bend forward or backward, which is painful for them. Other times, there are patients who cannot hold their breath for a long time. The VELOCITY-U is very useful at such times because of its short processing time and flexibility," Nakajima said.
VELOCITY-U uses FNC (Flexible Noise Control) technology, which greatly reduces the amount of noise on the images. This technology is especially effective when imaging body parts where a higher level of noise is anticipated. Another technology is the EDR (Exposure Data Recognizer), which enables a stable high-resolution image.
After using the VELOCITY-U for several months, Nakajima discovered that high-quality images could be obtained with lower exposure dose, which subjects patients to less radiation risk. He conducted experiments using the VELOCITY-U to prove that the exposure dose could be cut by 30% compared to film-screen radiography.
"If I may say so, the X-ray image is not an artistic piece of art and therefore does not require the high resolution of a masterpiece. Resolution sufficient to diagnose the condition of the illness is all you need," Nakajima said.
The radiographer believes it is his ethical responsibility to decrease radiation exposure to patients as much as possible.
"I would like to stress that we, as responsible radiographers, should be more aware of the patient's well-being and strive to decrease the dose they receive," he said.