Below we have mentioned the steps on How to create Report Fields for Investigation / Radiology Items : 

Step 1-  Go to "Lab" -> "Lab Billing Items Setup" and click on "+New Item".

Step 2-  Enter the Item Name, Amount and Department. For Radiology item check the "Is Radiology?" option.

Step 3-  Scroll down and click on "+Add New" option to add the report fields.

Step 4-  Enter the Field Order, Field Name, Field Type, Unit, Ref. Value and Formula, to add more report fields click on "+Add                     New" option.

Step 5- After entering all the details click on "Save All Changes" option present below.

Below is the video on How to create Report Fields for Investigation / Radiology Items :

Field Type