Tips & Tricks: Preventative Dose Alert on CT Scanners
Athina Gorezis | 26-06-2017
Learn how to prevent unnecessarily high radiation doses with instant alerts if predefined CTDIvol and DLP values are exceeded.
‘Dose Alert’ is an integrated dose warning tool available on Siemens CT scanners with 2011A software and later. It is a practical response to an industry-wide action to promote dose awareness and prevent unnecessarily high radiation dose in CT examinations.
Fig. 1: The functionality ‘Dose Alert’ is located in the Options-Configuration-Examination card.
Defining dose values
CTDIvol values are predefined for CT examinations of both adults and children at 1000 mGy. These values are set according to recommendations by the FDA (Food and Drug Administration, USA) and come as the default setting. Values may, however, be modified by the user to adapt to their country or clinical practice guidelines. Moreover, it is possible to define specific dose length product (DLP) values. A ‘Dose Alert’ message box appears if the accumulated CTDIvol or DLP, plus the estimated values for the next confirmed scan range, exceed the corresponding ‘Alert Value’ that has been set. A diagnostic reason together with the user name must be entered before the scan can be performed with these settings. Siemens Healthineers personnel cannot determine or advise on ‘Dose Alert’ values. This needs to be done by a qualified person at an institution.
Fig. 2: A ‘Dose Alert’ dialog box appears if the predicted CTDIvol and DLP values will be exceeded for the examination.
‘Dose Alert’ procedure
To modify the default ‘Dose Alert’ values on your system, go to ‘Options’ then ‘Configuration’. Open ‘Examination Configuration’ and select the ‘Dose’ tab and within this section select ‘Dose Alert’. Highlight the predefined value and then press delete or backspace. Now, enter your chosen value and click on ‘Apply’ and ‘Okay’. Your new value is now set as the alert. If the cumulative dose in a multiscan CT procedure exceeds the alert value set, you will be notified and required to confirm or change scan settings before proceeding with the next scan. User details are required at this stage and this information will be stored as an easily accessible text file for site review. It is located in ‘Options’ under ‘File Browser’ then ‘Dose Logs’.
In addition, a ‘Dose Alert’ password can be set in the local service platform. This requires a service key to access.
Fig. 3: Dose logs can be found in ‘Options’ under ‘File Browser’ then ‘Dose’ for easy viewing or export.
About the Author
Athina Gorezis is Application Specialist at Computed Tomography, Siemens Healthineers, Germany
 AAPM Dose Check Guidelines version 1.0 04/27/2011