Film, CR and DDA radiography: compare the training workflows

Identify how the image reaches the learner

ASNT’s radiographic-testing overview describes film as an image receptor that needs processing before the image can be viewed. In a film syllabus, image formation and film processing are therefore distinct subjects to understand.

DÜRR NDT describes CR as a route from an imaging plate through a separate scanner to a digital image displayed on a computer. Plate readout is a useful landmark when you compare CR lessons with the other routes.

Varex explains that a digital X-ray detector converts the received radiation into electrical signals that are read electronically and processed into an image. In a DDA syllabus, follow the detector, acquisition electronics and software rather than a CR plate-reader route. Here, DDA means digital detector array; the academy’s DR add-on is focused on that technique.

Sources: ASNT: film and digital radiographic techniques; DÜRR NDT: the imaging plate and CR reader; Varex: digital detector signals and image formation.

Compare the topics after image capture

Use this map to locate subjects in the published curricula. It is a guide to what to study, not a sequence for performing an examination. The film, CR and DDA lessons address different equipment and different ways of handling the resulting record.

Find the misplaced lesson on three study cards

Imagine that a learner has copied topics into three study cards. Each card has a technique heading and one topic borrowed from another route. Before reading the answer, move each borrowed topic to the course outline where it belongs.

• Card F is headed Film RT, but its next topic is imaging-plate reader operation.
• Card C is headed Computed radiography, but its next topic is detector-array acquisition modes.
• Card D is headed DDA radiography, but its next topic is chemical film processing.

Separate a study comparison from permission to substitute

The card exercise helps you find the relevant lesson. It does not tell you to remove a requirement from an actual job, replace a detector, or transfer an authorization from one technique to another. A course outline answers a training question; the applicable procedure and qualification arrangements answer different questions.

The CR and DDA curricula also distinguish the original image from a derived view. When studying a software example, ask what the lesson identifies as the retained original and what processing produced the displayed view. Do not assume that “original” always means uncorrected detector data; the controlled system and procedure determine that definition.

Two similar-looking displays do not, by themselves, establish that the acquisition route, processing history or image information is equivalent. Keep your study notes specific: name the technique, the lesson topic and the question still to resolve.

Choose the training route that fits your starting point

If you are building your radiographic-testing foundation, review the RT Level I and Level II course outline. NDTAcademy’s separate CR and DDA Level II add-ons are intended for film radiographers who already hold RT Level II and are adding the relevant technique. Compare their prerequisites and lesson topics with your employer’s training plan.

The add-ons provide formal training, including equipment-familiarization lessons and simulations. They do not replace actual-system practicals or award employer certification. Confirm the applicable experience, examinations and qualification requirements with your employer or certification body before treating a completed course as authorization to work.