I believe what you want is to import a folder of files. Check the Help in FileMaker for details, but basically, you can map the image to a container field and the field name to a text field. Your Panel Number should be able to go into a text field, therefore, and the image into a container.
Should do what you need.
I run into this FM pro help titled "Importing a folder of files all at once"
Importing a folder of files all at once
FileMaker Pro can import a folder of files in a single operation. Instead of inserting several pictures or files one by one, you can import them all at once. You can also import a folder of text files, which is faster than copying and pasting the contents of each file.
FileMaker Pro can import any image file that you can insert with the Insert Picture and Insert QuickTime commands, including GIF, JPEG, EPS, TIFF, QuickTime Movie, and many other formats. Text files must be plain, text-only files with a .txt filename extension or a TEXT file type.
You can import a folder of image files into a container field, or import a folder of text files into a text, number, date, time, timestamp, or container field. In addition to the file content, you can also import information about each file: the filename, the file path, and (for picture and movie files only) a smaller thumbnail image.
Hope it helps.