Frequency of gout in the United States has tripled in the last 50 years, but the realm of medical imaging has seen even more exponential growth. A group from UCLA has released designs for a system that provides a field of view 100 times larger than the former â€œgold standardâ€ for gout diagnosis.
The “gold standard” in gout diagnosis since 1961 has been the use of Compensated Polarized Light Microscopes (CPLMs) to identify the disease’s signature crystals of uric acid (monosodium urate; MSU). In the half-century since, the frequency of gout in the U.S. has more than tripled, and today it causes painful joint inflammation in over 8 million Americans.
Fortunately, imaging technology has advanced even more exponentially in that same time period. Utilizing recent image sensor developments, a group of researchers from UCLA this month published designs for an imaging system that could make gout diagnosis substantially more reliable and cost effective. Based on lens-free on-chip microscopy, the platform includes Complementary Metal Oxide Semiconductor (CMOS) sensor chips, commonly found in smartphone cameras.
The system uses holographic imaging to produce high-resolution glimpses of a patient’s synovial fluid sample, and represents a dramatic improvement on existing methods. A CPLM typically allows for a field of view (FOV) of about 0.2mm2. The new design can produce an FOV over 100 times that size, at 20mm2 or greater. The relatively small image size of the CPLM required deliberate examination and relied heavily on the skill and training of the eyes examining it. A vastly larger image should improve the reliability of gout identification.
Another limitation of CPLMs that the UCLA design could rectify is sheer accessibility. A CPLM is large and unwieldly, and can cost in excess of $10,000. Observational studies showed that as few as 10% of primary care physicians actually used the old “gold standard” to diagnose gout. The proposed device can cost as little as $250 (not including the PC interface), and is significantly more field-portable.
“With its wide sample area, cost-effectiveness and portability,” lead researcher Aydogan Ozcan says in a corresponding press release, “our microscope can significantly improve the efficiency and accuracy of gout diagnoses, and it can be deployed even at the point of care and in clinical settings with limited resources.”
The study, which was published in Scientific Reports, was supported by a Presidential Early Career Award for Scientists and Engineers and by the Army Research Office Life Sciences Division, among others. The accompanying press announcement suggests this new design could be effective in diagnosing other conditions that also involve crystallization in body fluids, such as kidney stones.