Dalsa says it has planned four and six-megapixel sensors. “The increased sensitivity of the new monochrome CCD sensors leads to improved detection at lower light levels, which reduces X-ray dosage for patient safety”, says Dalsa product manager Yves Kessener.

Existing six and 12 megapixel CCD sensors (3,072 × 4,096 pixels) give equipment builders a choice of two dual-output registers using different amplifiers, for either a high signal-conversion gain or maximum full-well capacity (the greatest number of carriers a detector pixel can accumulate per cycle) for the best signal to-noise ratio during long exposure times. In addition, some sensors have outputs at each corner of the image area for single, dual, or quad parallel outputs to support full resolution image capture at video speeds. Other features include high sensitivity and a durable ceramic case.

Smarter software

Developments in software are providing physicians with more tools to detect diseases, find lesions, and measure stenoses in vessels. PET (positron emission tomography) for one, works by detecting radiation from tracers injected into patients, and CT can look at blood flow by visualizing contrast agents injected intravenously into patients. Perfusion exams use PET or CT to look at the arrival of a tracer or contrast agent at an organ or lesion over some period. Clinicians then compare curves generated during a perfusion exam to determine the extent of injury to the heart or brain, if a patient has had a heart attack or stroke. Perfusion-analysis software helps, for instance, determine how much brain tissue is viable and may be used to decide an appropriate treatment.

For perfusion studies in the body, the physician may want to cover a larger anatomic volume than the brain or heart. Ackelsberg says for this, GE has developed what it calls a helical-shuttle technique. This refers to the path generated by the x-ray tube rotating around a patient while the table moves back and forth. The technique can cover up to 250 mm of thoracic anatomy to provide perfusion data and dynamic contrast imaging. The system minimizes patient dose by modulating X-ray energy levels during the table's acceleration and deceleration. He adds that the helical-shuttle technique maintains high image quality with minimal artifacts.More importantly, the technology covers what would otherwise require a 400-slice detector, one with the potential to generate “cone beam” artifacts from geometric distortion posed by such a large detector.

“In addition, every PET scanner from our company is now a hybrid PET-CT device. CT captures anatomic information for the localization of, say, a particular lesion, as well as attenuation information that lets the PET scanner provide more accurate measurements,” says Acklesberg.

Other innovations include 4D PET-CT and Motion-Free PET imaging. “A PET scan takes several minutes to acquire, too long for a patient to hold their breath. With traditional PET-CT imaging, small tumors move around with patient breathing and get blurred out. With 4D PET-CT and motion-free reconstruction, we can track anatomy motion to accurately see and measure lesions. This may improve lesion detection for staging along with therapy planning and monitoring,” adds Ackelsberg.

After collecting data, software manipulates it to tease out useful information. For instance, one company's add-on to its own diagnostic medical software is said to allow quantitative and visual analysis of heart dynamics using 40 slices of CT data. The add-on software works with a user interface of the Visage CS Thin Client/Server and Visage WS workstations from Visage Imaging, Carlsbad, Calif., (visageimaging.com). Parameters, such as left-ventricle volumes and wall motion, are computed and shown in a bull's eye representation according to American Heart Association recommendations.

Visage says its cardiac analysis avoids having to request Dicom (Digital imaging and communications in medicine - a communications standard for imaging devices) data and waiting for what can be complex and error-prone data transfers. Visage says its software allows cardiac analysis from any workstation or office PC, rather than from expensive, dedicated workstations that are not always conveniently located. The software also lets clinicians share results.

CT data from different machines can be managed and archived in one central PACS, a medical-image database. Data then becomes available anytime inside and outside the facility through the Web and the thin-client software.

How doctors view data is also changing. Traditional CRTs have given way to higher resolution flat panels and even those are upgraded constantly. A few developers are examining 3D images as holograms.

Can you see it now?

The medical industry has recently benefited from a variety of display technologies, such as, LCDs that alleviate the color shift of backlight to the yellow spectrum, and controls that adjust luminance and white point (a reference white) to maintain factory calibrations. NEC Display Solutions, Itasca, Ill. (necdisplay.com) says such innovations are now leading to additional improvements such as:

• Stand-alone calibration

  “New monitors must often be calibrated to match the color outputs of the older units,” says Todd Fender, NEC Display product line manager. “Modern displays are configured with built-in, stand-alone calibration algorithms.” The option is useful because not all monitors are easily calibrated using a PC and external software, or nonsupported operating systems.

• Greater color output

  “New screens accurately represent colors that were captured, edited, and are to be output to print, film, or other media. This eliminates having to make color proofs, as is typically needed with traditional displays, to accurately check colors outside the display's color range,” he says.

• Greater image accuracy

  “NEC's ColorComp reduces display-uniformity errors to almost unnoticeable levels by digitally correcting each pixel to compensate for color and luminance differences. Savvy manufacturers are using systems that measure hundreds of points across a screen at different gray levels. Such measurements are used to build a 3D correction matrix for the screen, which is stored in the display,” says Fender.

• More “green” in LEDs

  “LED monitors have large color pallets, uniformity, stability, and repeatability. But ultra-bright LEDs now have power consumptions comparable to CCFL (Cold cathode fluorescent lamp) LCD displays, and a lifetime of about 50,000 hrs, twice that of CCFLs. Unlike CCFL backlight displays, which contain mercury, the fluorescent-lamp LEDs are mercury free and RoHS compliant,” he says. Expect to see more LED monitors.

In addition to HD flat panels, holographic images are getting attention. “A holographic image starts with Dicom data from either CT or MRI, and instead of looking at it on a computer, we laser image each slice onto a single holographic film,” says Holorad President Daniel Burman. “We send the film to the surgeon who puts it on a viewer which generates a 3D image of the anatomy and pathology floating in air in front of them like a sculpture of light. Surgeons can take the hologram into the OR and stick their hands into images with tools or measuring devices. Surgeons say it's quick and intuitive.”

Burman says holograms can combine information from CT and MRI scan for a more complete picture. He says success of surgeries are improving thanks to imaging from the holograms and other viewing methods, especially when it comes to the brain and cranial cases where precision is the major concern along with the length of time under anesthesia. Tumors are particularly interesting, he adds, because contrast agents given to patients before a scan lights up the tumor in the holograms.

Fluoroscope cuts dose ratesto 0.5% of conventional

A recent high-sensitivity X-ray fluoroscope with dose rates about 1/200th that of conventional fluoroscopy will take highly magnified, non-invasive fluoroscopic shots of stents and other implants. Developer Glenbrook Technology Inc., Randolph, N.J. (glenbrooktech.com) says it will help properly position implants and diagnose developing problems such as restenosis.

The MicroFluor works like a fluoroscopic X-ray microscope with a 50-mm field of view. The fluoroscopic image shows details 10 times larger than conventional fluoroscopy. Real-time X-ray video is magnified more than 20 times and recorded as stills or movies. The technology is based on Glenbrook's proprietary X-ray imaging using high-resolution radioluminescent phosphors, night vision, and auto-focus, programmable CCD cameras.

Software makesscanning microscopes smarter

Software for laser scanning microscopes combines design tools with traditional optical and mechanical precision for more intuitive user-guidance, according to developer Carl Zeiss Micro-lmaging, Thornwood, N. Y., (zeiss. com). The company says the user interface can be tailored for experiments and users. In addition, the Professional-Basic concept of the Zen software is said to reduce complexity of the interface without reducing its range of functions. Settings can be saved and sent to other users.

Learn more at MedicalDesign.com by selecting the Engineering/Prototyping tab.