Abstract: | Pathological crystal identification is routinely practiced in rheumatology for diagnosing arthritis disease such as gout, and relies on polarized light microscopy as the gold standard method used by medical professionals. Here, we present a single‐shot computational polarized light microscopy method that reconstructs the transmittance, retardance and slow‐axis orientation of a birefringent sample using a single image captured with a pixelated‐polarizer camera. This method is fast, simple‐to‐operate and compatible with all the existing standard microscopes without extensive or costly modifications. We demonstrated the success of our method by imaging three different types of crystals found in synovial fluid and reconstructed the birefringence information of these samples using a single image, without being affected by the orientation of individual crystals within the sample field‐of‐view. We believe this technique will provide improved sensitivity, specificity and speed, all at low cost, for clinical diagnosis of crystals found in synovial fluid and other bodily fluids. |