Question 803
{"accessible":false,"alternatives":[{"id":4062,"text":"the display is wrong"},{"id":4063,"text":"the skin entrance dose rate is too high"},{"id":4064,"text":"the skin entrance dose rate is normal"},{"id":4065,"text":"the skin entrance dose rate is too low"},{"id":4066,"text":"the x-ray tube is too close to the patient"}],"archived":false,"correctAlternativeId":4063,"explanation":"\u003cp\u003eABC systems are generally designed to operate between minimum (e.g. 70 kV) and maximum (e.g. 120 kV) kilovoltages. The minimum kV can be used at the start of an exposure sequence, for instance, to prevent low energy X-rays exposing the patient unnecessary, and is then increased automatically so that a pre-determined image brightness level is reached. The tube current (mA), usually 1 mA in fluoroscopy, can also be adjusted automatically during this process.\u003c/p\u003e\u003cp\u003eWhen this product reaches the power limit, in the case of a very large patient, for example, the ABC generally maintains constant kV and mA settings.\u003c/p\u003e\u003cp\u003eAdapted from\u0026nbsp;\u003ca href=\"https://en.wikibooks.org/wiki/Basic_Physics_of_Digital_Radiography\"\u003eBasic Physics of Digital Radiography\u003c/a\u003e\u0026nbsp;by\u0026nbsp;Kieran Maher,\u0026nbsp;with author's permission (License:\u0026nbsp;\u003ca href=\"https://creativecommons.org/licenses/by-sa/3.0/\"\u003eCreative Commons\u0026nbsp;BY-SA 3.0\u003c/a\u003e).\u003c/p\u003e","id":803,"imageUrl":null,"imageAttribution":null,"imageAttributionCaseInfo":null,"firstQuestionPath":"/questions/803","nextQuestionPath":"/articles/entrance-skin-dose/questions/759","relatedArticles":[{"id":29650,"title":"Kilovoltage peak","link":"/articles/kilovoltage-peak?lang=us"},{"id":52641,"title":"Image intensifier","link":"/articles/image-intensifier?lang=us"}],"alsoUsedIn":[],"stem":"\u003cp\u003eThe fluoroscopy factors displayed on a monitor are 120 kV and 20 mA. Which one of the following statements is true?\u003c/p\u003e","menuLinks":[{"text":"Report problem with question","url":"https://docs.google.com/forms/d/e/1FAIpQLSfO3soWYhOjJ7yErSysyCe5V4A1CqW7WK3rDA7MtAkecMGqNw/viewform?entry.1624461248\u0026entry.553583435=https://radiopaedia.org/questions/803"}],"attemptsPercentages":[{"alternativeId":"4062","percentage":9},{"alternativeId":"4066","percentage":6},{"alternativeId":"4065","percentage":11},{"alternativeId":"4064","percentage":16},{"alternativeId":"4063","percentage":58}],"promptToLogin":false,"questionManager":false,"articleId":"entrance-skin-dose"}