The Wikipedia entry for "Clinical Technologist" offers a good discussion of the nomenclature problems with this profession: "A clinical technologist, also known as a healthcare science practitioner, is a medical professional involved in the practical delivery of medical physics and clinical engineering services. In some locations there is considerable overlap in closely related terms, for example in many countries technologist and radiographer are synonyms, while in the United Kingdom they are considered separate professions. Clinical technologists can be found in nuclear medicine, radiotherapy, radiation protection, and rehabilitation engineering departments, and they are often described by their scope of practice (for example as a nuclear medicine technologist<b/>).[1][2]"

Since imaging and nuclear medicine technologists appear to be separate professions in the UK, US and Canada, and no equivalent profession exists, I would use the literal "Diagnostic Imaging and Nuclear Medicine Technologist".

"Depending on local practices, in radiology and radiotherapy technologist may be a synonym for radiographer or a separate position.[3][4] The International Atomic Energy Agency (IAEA) uses technologist primarily to refer to the staff involved in the practical clinical delivery of radiotherapy, radiology and nuclear medicine.[5][6]

There is no single European Union definition or minimum training level for technologists, and the use of the term varies between member states.[7] In radiotherapy, the European SocieTy for Radiotherapy and Oncology (ESTRO) previously referred to the staff carrying out the practical elements of treatment as Radiation Technologists (RTT),[8] however they have since revised this to Radiation TherapisTs.[9]

In the United Kingdom, clinical technologists and radiographers are separate professions with differing responsibilities. In X-ray radiography and radiotherapy, it is radiographers who will carry out the imaging or treatment, while technologists may be involved in equipment testing and radiation protection activities.[1][10] In nuclear medicine however, those with technologist or radiographer training largely have the same responsibilities.[11]

In the United States, and many other countries, technologist is the main term for the healthcare professionals performing diagnostic imaging (radiographers), as well as the staff involved in testing and quality control of X-ray equipment, with the latter specifically known as quality control technologists.[12] Similarly in Canada medical radiation technologists (MRTs) carry out practical aspects of radiology and radiotherapy on patients.[13]"