 With Jacques Forestier (1890-1978), he introduced lipiodol (radio-opaque iodized poppyseed oil) for use in radiological investigations.Lipiodol was injected into a patients' cerebrospinal fluid for myelographic diagnosis and localization of intraspinal cysts and tumors.Sicard is also credited for introducing injections of sodium salicylate for treatment of varicose veins, as well as alcohol injections for relief of trigeminal neuralgia.