With the increased demand for faster diagnosis enabled by current and future digital medical tools, microwave sensing and imaging systems offer key advantages such as real-time scanning and faster cycle times. (Image: Keysight Technologies)

Magnetic resonance imaging (MRI) and computed tomography (CT) scanning have improved and extended millions of patient lives by giving medical professionals high quality images of injures, tumors, infections, internal bruises, and other areas of concern within patient bodies. While the value of these systems is undeniable, their size, capital cost, and per-use cost limit their availability in certain applications.

Microwave sensing and imaging (MSI) technology, which has been in for many years, has now improved to the point that it may usefully supplement or even replace MRI machines and CT scanners in certain applications, including stroke detection and breast cancer detection. While microwave sensors cannot produce images of the same resolution and contrast that MRIs and CT scans produce, they do have many advantages that make them excellent options for many applications that could provide substantial value to patients and medical professionals. These advantages over MRI and CT scan technology can be summarized as follows. Microwave sensing has the possibility to be accessible to more patients, produces useful results in less time and can do applications beyond imaging. The technology also has advantages for patient safety and comfort, and has many advantages throughout the technology lifecycle for health delivery organizations (HDOs).

Accessibility to More Patients

Microwave sensors are compact and portable, which make them suitable for use as a mobile device. Their portability could enable routine screening and tests for large groups of people who may not have a hospital with an MRI machine or CT scanner nearby. They can be used in emergency situations where a patient cannot get to a hospital. The lower capital investment for microwave sensors makes them more affordable for hospitals, medical office buildings, and even ambulance companies. Furthermore, a hospital could have MSI systems, which reduces the challenges associated with scheduling time on MRI and CT scan machines.

MSI systems also have a faster cycle time for each patient use, and they are less expensive on a per-use basis than the big systems are. These factors mean that a given patient can be tested more frequently for the same amount of money, which can be important in where there are highly dynamic phenomena in patients, such as fast-growing tumors.

MSI systems have a faster time to results than MRIs and CT scans. This allows diagnosis and treatment to begin sooner, which is important in urgent and emergency care. While the images produced by microwave sensor imaging systems do not have the resolution to provide a “good enough” answer in a context where large systems may not be available. This provides valuable information to patients and medical professionals who might not have any information at all if they did not have access to an MRI system or CT scanner. Because images produced from microwave sensors are low resolution, they may not require highly trained professionals to interpret their results. This reduces costs and provides answers sooner for patients and their caregivers.

Applications Beyond Static Imaging

Microwave sensors can sense and measure tissue perfusion thanks to their fast speed, which is something that MRIs and CT scanners cannot do. This allows for the detection of restrictions, blockages, and leaks. Microwave sensors can detect and measure differences in dielectric properties, which may assist in the diagnosis of conditions characterized by unusual dielectric properties. They can also measure the water content in a substance, which could help doctors diagnose conditions characterized by unusual concentrations of water, either too high or too low. All these additional capabilities could be used in fields outside healthcare, including food quality and industrial material processing applications.

The greater speed of microwave sensing makes it more suitable for real-time scanning applications. These could allow medical professionals to get real-time information, which is helpful in diagnosing highly dynamic conditions and understanding how patients respond to various treatments and stimuli.

Compact, portable microwave sensing and imaging systems now offer a viable alternative to large, stationary magnetic resonance imaging and computed tomography systems (pictured) for medical imaging. (Image: Keysight Technologies)

The system size and complex safety rules associated with MRI systems and CT scanners make them unsuitable for use during most procedures. The compact size of microwave sensors offers more possibilities to provide clinicians with useful information during procedures. Because microwave sensing is relatively easy and inexpensive, it is more feasible for patients to undergo multiple re-checks over time. Each recheck gives data that doctors can use to help patients. Microwave sensing systems also have the potential for continuous patient monitoring, such as during recovery. This also provides clinicians with more information to help patients faster and with greater efficacy.

MSI uses non-ionizing radiation, which is safer for the patient. This allows for much longer periods of use and greater frequency of use. MSI does not produce strong magnetic fields, so it can be used in patients with metal (ferromagnetic) implants or devices. Also, there is no possibility of damage to MSI machines from flying metal, which is not true for MRI machines with strong magnetic fields.

MSI has no risk of hot spots on the patient’s body. This is safer for the patient, and it reduces a potential area liability for hospitals and medical professionals. MSI does not require patients to go into a system, unlike larger systems, which sometimes require the use relaxation drugs for claustrophobic patients. Not only is the need for drugs reduced, MSI does not require the introduction of contrast agents into the patient’s body. This not only saves money, but it also leads to a faster procedure that does not risk the side effects associated with the contrast agent.

With MSI systems, there is no need to worry about positioning and moving patients, which could be very painful for an injured patient. There is also no concern about fitting very large patients or patients with limited mobility into an MSI system. This improves safety and comfort for patients, allows more patients to benefit from the technology, and produces results faster.

In summary, the simpler and faster setup time per patient saves money for the hospital and the patient, improves equipment utilization, reduces patient risk, and gets critical information to doctors sooner.

Advantages Throughout the Technology Lifecycle for HDOs

The numerous advantages that microwave sensors have over large systems throughout the technology cycle begin as soon as the HDO places an order. Unlike an MRI machine, for example, MSI does not require liquid helium, which is a limited resource that requires great care in shipping and handling.

The hospital infrastructure associated with MSI is much smaller and simpler than that associated with large systems. There is no need for high-voltage electrical service, cooling, space around the machine, a control room, and so on. A microwave sensor system does not require as much time to install and calibrate as an MRI machine or CT scanner does.

Once the system has been shipped and installed, there are ongoing costs that must be considered. MSI uses much less electricity in operation and requires no electricity for cooling. The ongoing maintenance costs of microwave sensors are also much less expensive. There is no complex and laborious mechanical alignment required, the list of repair parts is simpler, and the repair parts themselves are less expensive. The training required to maintain an MSI system is relatively simple, and it may be suitable for the HDO’s technical staff to perform, which can result in lower costs and less downtime.

An MSI has no complex moving parts that can be subject to wear, as opposed to MRI, which has a large rotating coil. Finally, the cost and complexity associated with decommissioning and disposing of MSI systems at end of life are much smaller than for the large systems. The de-installation, shipping, and environmental costs are all much less.


MRI systems and CT scanners continue to be important systems for high-resolution healthcare imaging, and that will be true for years to come. MSI systems cannot produce the high-quality images that these large systems can, but their lower cost, compact size, faster speed, and other advantages may allow them to provide value to patients in applications where the larger systems are either unavailable or inappropriate for a particular application.

This article was written by Brad Jolly, Healthcare, Technical Specialist, Keysight Technologies (Santa Rosa, CA). For more information, visit here .


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