Picker's ViewPoint adds to line of image-guided therapy products

Workstation complements imaging modalities

ISG Technologies may soon find the competition heating up in themarket for image-guided surgery workstations. Multimodality vendorPicker International of Cleveland is developing its own image-guidedsurgery workstation, dubbed ViewPoint.

ViewPoint is just one piece of an overall strategy Picker isimplementing to gain a foothold in the emerging image-guided therapymarket with a full line of complementary products. The strategyincludes integrating ViewPoint with modalities such as magneticsource imaging and interventional MRI, according to the company.

ViewPoint consists of a high-powered computer workstation anda hand-held probe used by surgeons, said Donald W. Kormos, managerof computer-assisted surgery and advanced NMR technology.

Clinicians first collect CT or MRI three-dimensional volumescans of a patient and register those images spatially to thepatient's anatomy using fiducial markers attached to the patientwhen he or she is scanned. This approach is less invasive thantraditional forms of stereotaxy using a frame that is attachedto the patient's head.

When the patient goes into the operating room, the surgeonuses a hand-held pointer, which is part of a 3-D digitizer, tocorrelate the positions of the fiducials on the patient with theirpositions in the 3-D image volume data in the ViewPoint workstation.For the remainder of the procedure, the movements of the probeand other surgical tools register on the MRI or CT images displayedon ViewPoint's CRT monitor. This allows surgeons to localize specificanatomical structures and orient the positions of surgical toolsrelative to those structures.

ViewPoint's approach to image-guided surgery is similar tothat of ISG Technologies, which began marketing its Viewing Wandworkstation earlier this year (SCAN 5/4/94).

ViewPoint differs from Viewing Wand in the way the hand-heldprobe is integrated with the workstation, however. Viewing Wand'sprobe is mounted at the end of an articulated arm, while ViewPoint'sprobe is attached via a cord and is registered to the workstation'simages via ultrasonic sensors.

Picker expects image-guided neurosurgery to be an early clinicalapplication for ViewPoint. For example, ViewPoint would enablesurgeons to select the smallest possible entry hole through theskull during a craniotomy and avoid critical anatomy in selectinga surgical route to a lesion or other pathology, Kormos said.Other applications could include image-guided placement of pediclescrews in the spine, orthopedic surgery, endoscopic surgery andinterventional radiology.

ViewPoint is also being used for MRI-guided breast biopsy byDr. Nandita de Souza of Hammersmith Hospital in London. DeSouzais using ViewPoint with Picker's 0.5-tesla Asset scanner. Pickerdeveloped ViewPoint with the Cleveland Clinic.

ViewPoint runs on a DEC Alpha AXP workstation, with a Unix-basedoperating system and an X-Windows with Motif graphical user interface.It also features dual 2.1-gigabyte disk drives for system softwareand patient data. A RAID level 1 configuration provides disk mirroringfor back-up in the event of single-disk failure. The system isDICOM 3.0-compliant for interfacing with scanners from other vendors.ViewPoint's display matrix is 1280 x 1024.

Picker has contracted with Biometric Research Institute toconduct multi-center clinical trials using ViewPoint to investigatecraniotomy and spinal surgery applications. Data from the trialswill be used to support a 510(k) application expected to be filednext year.

ViewPoint can be integrated with other products that Pickeris developing for the image-guided therapy field, including theNeuromag-122 magnetic source imaging scanner and a new interventionalMRI system in development. Picker has targeted image-guided therapyas a means to expand sales outside the traditional universe ofradiology, according to Surya Mohapatra, vice president and generalmanager of the vendor's NMR division.

"The radiology market has shrunk. The role of the radiologistis also shrinking," Mohapatra told SCAN. "We have tofind a way to provide an image, whether it is to a surgeon ora referring physician."