Whether it’s equipping your infrastructure with a Wi-Fi network or working on multimodality iPhones, wireless technology has sparked innovation in radiology.

Technology has given radiologists yet another tool to advance productivity, performance, and efficiency: wireless communication. Although still in its infancy, Wi-Fi is emerging as the next great leap in medical imaging.

“Wi-Fi” is an ambiguous term, with no specific, agreed-upon meaning except perhaps “wireless fidelity.” It is a trade name for popular wireless technology in home networks, mobile phones, video games, and more. Wi-Fi is supported by nearly every modern personal computer, operating system, and most advanced game consoles.

Now it is emerging as a significant tool for radiologists.

According to surveys, the number of hospitals that are considering wireless radiology implementations over the next 2 years will double. More than 65% of hospitals plan to implement a wide range of wireless solutions. Concerns over patient safety, security, and HIPAA compliance are challenges to implementation. In January 2007, the FDA issued a Draft Guidance for Industry and FDA Staff regarding Radio-Frequency Wireless Technology in Medical Devices. In the document, the FDA outlined serious issues associated with wireless implementations in hospitals and by medical device manufacturers. The FDA recommendations concerned performance of wireless functions, wireless coexistence, integrity of transmitted data, security of data, radio-frequency (RF) emissions affecting other medical devices, electromagnetic interference impacting on the operation of other medical devices, and the crowding of frequency bandwidth as the use of RF wireless technology increases.

The requirements for a secure wireless system are extensive and daunting. They must meet HIPAA requirements for controlled, authenticated access and encryption. They must be highly reliable measured by availability of the network and minimize signal loss and interference. The system must have the ability to manage access points and user access, including the ability to provide reliability metrics, usage patterns, and reports. The design capacity must be flexible enough to ensure bandwidth availability as new Wi-Fi devices and applications go to production. It must be tested for a variety of applications, devices, and usage patterns. Troubleshooting must be possible and easy. In the end, the entire infrastructure must be as reliable and dependable as any network, including backup capabilities.

More Than 1,000 Devices

The number of wireless digital devices that are available to a Wi-Fi network are legion. They include clinical mobile devices (typically laptops and workstations on wheels); smart infusion pumps that use wireless connectivity for downloading formulary and sending events with data to EMR; temperature sensors for drug/blood refrigerator monitoring; electronic charting workstations on wheels; mobile imaging devices, including CT, XR, DR units, and mobile ECG and EEG carts; wireless pharmacy units, typically mobile PDA devices; and many other emerging Wi-Fi applications.

Typical applications involve interpersonal communications, including wireless VoIP, wide-area voice, paging, and messaging. Wi-Fi provides workflow improvements for transmitting clinical data, wireless monitoring, infusion therapy, asset management, and patient tracking. In hospital operations a Wi-Fi system aids building automation, security and surveillance, and first responder needs such as the fire and police departments.

Pam Jorgensen, director of clinical engineering for Seattle’s Harborview Medical Center, has been instrumental in setting up a wireless network at her institution. “Fifty to seventy percent of staff now have wireless capabilities,” she said. Jorgensen outlined the building blocks of a Wi-Fi network. “You need access points that can support various bandwidths and frequencies, and a service set identifier (SSID) that constitutes the name of the wireless network. You must have management software; a central software application that allows remote configuration and management of all access points.”

You also must have a channel. The Wi-Fi signal range is divided into smaller frequency segments called channels. A 2.4GHz Wi-Fi can have as many as 64 channels. Changing channels to avoid collision with wireless phones and radio devices is a good practice. And finally, you also need a wireless intrusion prevention system (WIPS). WIPS monitors airwaves to detect wireless threats.

The proper implementation of a Wi-Fi network in a medical environment includes these considerations: allow no rogue access points, all clinical devices must be tracked by a MAC address, all access points should be monitored and managed, all nonclinical devices (such as personal laptops) should use the virtual private network connection and a separate SSID, and clinical applications should receive the highest quality of service priority while personal devices (laptops, PDAs) should receive the lowest.

Other policies also apply. Studies have shown that 70% of a technology’s life-cycle cost is influenced by design. Good design practices are necessary to build and manage a medical-grade Wi-Fi infrastructure. Design the network with adequate APs to allow geographic coverage and capacity growth by adding more APs. Management areas also include tracking signal quality, remote configuration, tracking devices, and associated access points by a MAC address. Also consider network traffic monitoring by SSID and AP. Also necessary is a spectrum analyzer to measure frequency drift in medical devices that monitor outside internal outside/internal interference.

Security and Other Challenges

A key challenge is security. “Encryption, identification of authorized versus unauthorized devices add to complexity,” Jorgensen said. “To differentiate between clinical, mission-critical, specialty, and office devices is difficult since not all vendors adhere to a common security and encryption standard. One of the biggest challenges is to restrict hacked or stolen data.”

Resolving a user issue remotely can be difficult as the Wi-Fi signal-to-noise ratio varies by location. Interference from nearby devices is possible, and misconfiguration of access points and devices are likely causes of trouble. Compatibility with diverse device standards in terms of IP protocol and frequency interference is difficult to maintain, as well as the ability to allocate bandwidth according to the type of device and application.

Other questions also loom. Jorgensen laments that user expectations in terms of Wi-Fi quality, availability, and timeliness of implementation are higher than often feasible. Who should own, manage, and maintain the Wi-Fi infrastructure—clinical engineering or IT? What are the best practices for managing Wi-Fi projects that cross so many functional areas in the hospital? As new clinical, regulatory, and usage issue emerge, what policies are required to address them?

The Latest Buzz

But changes are advancing rapidly. MIMvista Corp, Cleveland, a leading global provider of medical imaging and fusion software, recently announced the availability of a native iPhone version of its multimodality imaging application for iPhone and iPod touch. This innovative software allows a physician or patient to view medical images remotely, without access to an imaging workstation. “Imagine a doctor sitting with her patient, sharing images with him, iPhone to iPhone, or an oncologist interactively reviewing a radiation treatment plan,” said Mark Cain, MIMvista chief technical officer. “We have taken a complex desktop application, removed it from the realm of black art, and placed it in the hands of physicians and patients—and we have only just scratched the surface.”

This application provides multiplanar reconstruction of data sets from CT, PET, MRI, and SPECT, as well as multimodality image fusion. With the multitouch interface, users can adjust image sets and planes, fusion blending, window/level, and zoom. All data is transferred and stored with secure encryption to ensure patient privacy.

“Two years ago, none of this was possible,” Cain said. “Now, we have the capability for radiologists to see data on an iPhone, which is taking over the desktop in terms of mobile communication. In the future, we expect patients will be able to retrieve their own data upon request and deliver it anywhere.”

Peter F. Faulhaber, MD, director of Clinical PET for University Hospitals at Case Medical Center of Cleveland, said, “The MIM application for the iPhone is the essence of cool for a radiologist who thrives on image display. The software is fast and intuitive. I think referring physicians will be able to seamlessly review a patient’s images while consulting over the phone. Patients will be even more impressed.”

The release of the MIM for the iPhone application includes sample images. Individual patient data also can be downloaded from a MIM Workstation or Storage Server. This initial release is free from Apple’s App Store on iPhone and iPod touch or at www.itunes.com/appstore/ under the category Healthcare & Fitness. It is ideal for image review by referring physicians but is not intended for diagnostic purposes. A fully featured MIM Pro for the iPhone, for physician and radiology use, will be available in the future.

“The technology is advancing so fast that vendors are scrambling to find niches,” Cain said. “Soon the referring physician can be anywhere to exchange imaging data like a phone call. The phone is taking over the desktop.”

James Markland is a contributing writer for Medical Imaging. For more information, contact .