How far should the tubehead and image receptor be during a cephalometric radiograph?

The distance between the tubehead and the image receptor during a cephalometric radiograph is critical for achieving optimal image quality and accurate results. The correct range of 1.5 to 1.8 meters allows for proper geometry of the radiographic procedure. This distance ensures that the x-ray beam diverges sufficiently to cover the entire area of interest while minimizing geometric distortion that can occur if the image receptor is too close to the source of radiation.

At this distance, the exposure settings can be optimized to capture a clear image of the cephalometric landmarks without excessive scatter radiation, which can degrade image quality. Additionally, maintaining this distance helps in aligning the patient properly within the field, ensuring that the anatomical structures are well-positioned relative to the x-ray beam and the receptor.

Choosing a shorter or longer distance might compromise the quality of the radiograph by either increasing distortion or reducing the sharpness of the image. Therefore, the 1.5 to 1.8-meter range is a standard practice in cephalometric radiography to uphold the integrity of the diagnostic process.