title: Patient radiation protection covers for head CT scans - a clinical evaluation of their effectiveness.
abstract: OBJECTIVE
  Although the use of thyroid shields for patients for head CT examinations is reasonable and even required by German regulations, so far available shields are often not used due to difficult applicability. New shields that are easier to use and therefore may gain wider acceptance and more frequent use are now available. In this work two new patient shields are investigated regarding their dose reduction effectiveness and applicability and compared to a thyroid/sternum shield typically used as a part of personal protective equipment.
  
  
  METHODS
  The reduction of organ doses for thyroid, sternum and mamma were measured with thermoluminescence detectors in an anthropomorphic female phantom. Additionally, the influence of the length or position of the overview scan at the beginning of the CT examination was taken into account.
  
  
  RESULTS
  Depending on the patient shield, a reduction of the organ doses for thyroid of 5 - 24 %, for sternum of 25 - 48 % and for mamma of 25 - 70 % could be found. A shift of 25 mm in the cranial direction for the overview scan resulted in a reduction of these organ doses of 12 - 15 %.
  
  
  CONCLUSIONS
  Patient shields for cranial CT examinations provide a considerable dose reduction. New models are easily applied and no decrease in image quality through reconstruction artifacts could be found. Therefore, it is advised to use shields which are applied upon the patient without the need to be wrapped around the neck and the overview scan should be positioned as close as possible to the examined region.
  
  
  CONCLUSIONS
  • New shields provide a compromise between usability and radiation protection.• Patient shields reduce organ doses even when not directly exposed.• The overview scan contributes considerably to out of field organ doses.• Shielding factors are greatly influenced by the positioning of the examination field.
authors.affiliation: Medical Radiation Physics, Carl von Ossietzky University, Oldenburg.
authors.forename: M
authors.initials: M
authors.lastname: Liebmann
authors.affiliation: Medical Radiation Physics, Carl von Ossietzky University, Oldenburg.
authors.forename: T
authors.initials: T
authors.lastname: Lüllau
authors.affiliation: Institute for Diagnostic and Interventional Radiology, Pius-Hospital Oldenburg.
authors.forename: A
authors.initials: A
authors.lastname: Kluge
authors.affiliation: Medical Radiation Physics, Carl von Ossietzky University, Oldenburg.
authors.forename: B
authors.initials: B
authors.lastname: Poppe
authors.affiliation: Center of Radiology/Nuclear Medicine and Academy of Radiation Protection, Klinikum Links der Weser, Bremen.
authors.forename: H
authors.initials: H
authors.lastname: von Boetticher
mesh_terms: D065638:Absorption, Radiation; D004867:Equipment Design; D005260:Female; D006257:Head / Q000000981:diagnostic imaging*; D006260:Head Protective Devices; D006801:Humans; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011835:Radiation Protection / Q000295:instrumentation*; D011859:Radiography; D012782:Shoulder / Q000528:radiation effects*; D013249:Sternum / Q000528:radiation effects*; D013819:Thermoluminescent Dosimetry; D013909:Thorax / Q000528:radiation effects*; D013961:Thyroid Gland / Q000528:radiation effects*