<prompt> In which of the following conditions sialography is contraindicated:Ductal calculusChronic parotitisParotid obstructionAcute sialadenitis  <response>: Main Indications of Sialography Salivary duct stones Stricture Fistula. penetrating injury Intraglandular and sometimes extra glandular mass lesions. Contraindications Iodine allergy Acute sialadenitis Contrast Water soluble media Meglumine diatrizoate 