2.0 Searching

Once our images have been indexed and the tag values stored in a library, we can search for images by their tag values. You perform searches using a workspace.

2.1

Opening a workspace

To open a workspace, click on the New workspace button on the toolbar. If you have only one library defined, DICOM Search automatically opens the workspace for that library. If you have multiple libraries, you will need to first select the library you want to search in, and click on the OK button. You can also double-click on the library to open the workspace.

2.2

Running you first search

The workspace is where you enter your search queries. Say we want to look for all ultrasound images in our library. This is what you have to enter in the query area: SELECT * FROM tags WHERE {00080060] = 'US' Then click on the Execute query button to start the search. DICOM Search will then display details of the 26 ultrasound images from our libary in the query results window. What we just did was run a SQL command against our index database to return all the columns for all the rows where the DICOM tag value for modality contained the value US (for ultrasound). Let’s break that down section by section. The query we entered was: SELECT * FROM tags WHERE {00080060] = 'US' We entered SELECT * because we wanted to return all the columns stored in our database. If you scroll the results area to the right, you will see all the columns that exist in the table, where each column represents a single DICOM tag. Not all columns will contain a value, because most DICOM images only fill in a couple of hundred tag values. FROM tags tells the database engine to search in the tags table. There is only a single table you need to use, and that is the tags table. WHERE [00080060] = ‘US’ tells the database engine to only return rows where the DICOM tag 0008,0060, which represents modality, contains the value ‘US’. To find the group and element value of a DICOM tag, click F2 when the cursor is in the query window. This brings up the Tags and Fields window. This will list down all the DICOM group and element values for the current library, together with the tag description where available. We can filter the displayed values by entering text into the Filter area. Say we enter modal e.g. Only DICOM tags with the word modal will be displayed. If we enter patient e.g. then only DICOM tag descriptions containing the word patient are displayed. Knowing this, say we want to retrieve only the patient’s name, birthdate, and age for all ultrasound images. This is the query we would enter: SELECT [00100010], [00100030], [00101010] FROM tags WHERE [00080060] = 'US' Now instead of over returning all the columns, DICOM Search returns only the columns we specified (00100010, 00100030 and 00101010) in addition to some other key columns. That is essentially how we enter our search queries - list down the columns we want to retrieve in the SELECT portion using the Tags and Fields window to help us e.g. SELECT [00100010], [00100030], [00101010] add FROM tags to tell DICOM Search to search the tags table, followed by the search criteria e.g. WHERE [00080060] = 'US' There is, however, a much easier way to enter our search queries.

Section summary

• Search queries are ran in workspaces. • SQL syntax is used to run your search queries.

Related help file topics

• Searching using SQL queries