Improved polarized light microscopic detection of gouty crystals via dissolution with formalin and ethylenediamine tetraacetic acid oleh Ruedee Hemstapat, Peeradon Duangiad, Borwornporn Tangketsarawan, Thitiya Phuagpan, Sinthida Chienwiwattanawong, Nuttinee Tangsrianugul, Akio Ojida, Jirarut Wongkongkatep