ADAC debuts gantryless dual-head gamma camera at RSNA meeting

Vendor believes Skylight could expand nuclear applications

Following up on the 1998 RSNA introduction of its dual-head, open-gantry-design Forte gamma camera, ADAC Laboratories took the open gantry concept to its logical conclusion with the 1999 RSNA introduction of Skylight, a work-in-progress dual-head unit that does not employ a gantry.

ADAC hopes Skylight will both make traditional nuclear medicine procedures easier and expand the modality’s applications. In terms of innovation, the firm believes the Skylight debut is on a par with its introduction of Vertex in 1993 and the launch of its molecular coincidence detection technology in 1996, according to Mohamed Elmandjra, vice president of marketing for the Milpitas, CA, firm.

“The introduction of Skylight is a significant step for us, and we expect the system’s openness to allow clinicians to take the nuclear medicine department beyond its walls and integrate it with other diagnostic modalities,” Elmandjra said.

Skylight leverages off technology developed for Forte, whose open gantry design allowed users to image patients on hospital beds, gurneys, and wheelchairs without detector arms or gantry feet getting in the way (SCAN 12/16/98). The Skylight prototype consists of two Forte detectors that can be installed on tracks directly into a room structure—from the ceiling or the walls, for example—or from a four-pole frame ADAC provides.

Skylight can fit in rooms as small as 10 x 12 x 8 feet, and it carries the firm’s CardioTrac and Rembrandt collimators, which allow the detectors to be placed close to the patient; in fact, the unit’s detector radius can be as low as zero. The device’s detectors can move in both linear and circular modes, together or independently. Users have access to a wireless, infrared remote control device that allows them to fine-tune the position of the detectors, and a touch screen allows clinicians to select preprogrammed positions in both modes.

Without a gantry, Skylight can increase a nuclear medicine department’s throughput for planar imaging; improve brain SPECT scans by eliminating the positioning restrictions imposed by a patient’s shoulders; allow for total body imaging on any bed or stretcher, as well as upright imaging; and give clinicians increased access to pediatric or claustrophobic patients and the ability to do lymphoscintigraphy procedures, according to the firm.

Future applications could include using Skylight’s detectors independently as single-head units, incorporating the device into cardiovascular assessment laboratories, or integrating it into neurological assessment procedures and guided surgery.

ADAC is in the process of applying to the Food and Drug Administration for 510(k) clearance for Skylight, and expects that the unit will be available worldwide in approximately 12 to 18 months, Elmandjra said. ADAC expects to install the device in its first U.S. clinical sites early next year.

The quest to solve the problem of nuclear medicine’s low spatial resolution is one of nuclear medicine’s cutting edges. Some vendors have attempted to improve spatial resolution by designing image fusion software that combines nuclear medicine studies with images from anatomical modalities, while others have begun to address the spatial resolution problem with hybrid units that combine PET or SPECT and CT scanners.

GE introduced its Functional Anatomic Mapping device at this year’s Society of Nuclear Medicine meeting in Los Angeles (SCAN 6/23/99). The unit, which has been cleared by the Food and Drug Administration and which GE calls Hawkeye internally, is a gamma camera based on the company’s Millennium VG platform. It produces both CT/PET and CT/SPECT images. At this year’s RSNA show, SMV presented Positrace, its work-in-progress PET/CT device (see story, page 2). Other vendors, such as Siemens and Marconi Medical Systems, have emphasized the software approach, although Siemens is working on a PET/CT unit.

Skylight reveals ADAC’s approach to the spatial resolution problem. Rather than developing a device that incorporates either a SPECT or a PET scanner with a CT system, ADAC hopes Skylight will help clinicians investigate the use of nuclear medicine with other modalities by installing Skylight next to CT, ultrasound, or x-ray suites, and then using a fusion protocol on the collected data. ADAC believes that only time will tell which strategy—software, hybrid units, or a camera such as Skylight—will prove most effective in addressing clinicians’ need for anatomic information combined with physiological data.

“The fusion of anatomic and functional data shows much potential,” Elmandjra said. “But the industry doesn’t know enough yet (about integrating nuclear medicine data with anatomic data) to have one answer. Our strategy is to give clinicians the ability to explore the use of nuclear medicine with other modalities: Rather than integrating another modality into a gamma camera, we’re making the gamma camera flexible so that it can be used with another modality.”