Whilst it should be generally possible to convert common JPEGs to DICOM images, it would be of no use, because the DICOM files (.dcm, .dicom) contain actual medical images, like x-rays thus, some random JPEG is useless for this purpose.
Convert JPEG bitmap image format to Medicine image file format.
We found one software available in the database for this conversion.
Multiplatform software - convert jpeg to dicom on any platform
A picture image editor
Convert from jpeg file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.