There are multiple definitions:

1. ultrasound contrast agent(English)

   • most indications concern injection as a bolus. Intravenous infusion is of interest in cardiac imaging and other indications. Wash-in and wash-out kinetics are produced with controlled destruction using US pulses with high MI
   • EUS, GI, MI, US, ARFI, CEUS, FDBF, IQ, LNA, TGC, SWEI, ULM
   • Ultrasound, Medical imaging, Gastroenterology
   • https://doi.org…303-9027.193594
   • https://doi.org…OC.2019.2932116

2. urocanic acid(English)

   • NMF, PCA, SC, AD
   • Allergy, Dermatology
   • https://doi.org…95.2010.02540.x