DR and CT are both X-ray machines used in hospital radiology departments. They have similar functions, but in practice, CT is used much more frequently than DR, and this trend has become increasingly apparent over time.
Nationwide, the ratio of CT to DR exams has evolved from a 1:1 ratio to a common 3:1, and some hospitals have even reached a 5:1 ratio. There are two main reasons why hospitals prefer to purchase and use CT:
- CT is more profitable than DR.
Taking a top-tier hospital as an example, from an investment recovery perspective, a DR machine costing 1 million RMB and a CT machine costing 15 million RMB have similar payback periods (around 1.5 years). From a long-term development perspective, because CT charges are significantly higher than DR, the benefits of CT are much greater than those of DR. Therefore, medical institutions at all levels prioritize profitability when choosing CT.
- CT is less prone to missed or incorrect diagnoses than DR.
In general, doctors are most concerned with missed and incorrect diagnoses in two types of DR exams: chest X-rays and extremity joint X-rays, with chest X-ray misdiagnoses being the primary concern. Let’s take chest X-ray misdiagnosis as an example to discuss DR.
According to clinical research on missed and incorrect diagnoses in chest DR, the overall misdiagnosis rate is around 3%. Further analysis revealed that four main factors contribute to missed diagnoses:
(1) Lack of careful observation (40%);
(2) Lack of clinical history inquiry (20%);
(3) Absence of lateral chest X-rays in the lung field area (30%);
(4) Poor DR image quality (10%).
This means that 90% of missed diagnoses with DR are unrelated to the equipment itself. For example, a common missed area on chest DR is the lung apex near the pleura, where it overlaps with the anatomical structures of the chest cavity. This is often due to the common practice of ordering only a frontal chest X-ray, with a lack of awareness regarding the importance of lateral views. Additionally, the heart and surrounding tissues can obscure many chest abnormalities in a frontal DR image. Another example is the area near the apex of both lungs, the upper mediastinum, and the diaphragm regions, which are located in the peripheral or edge areas of the lung field. These areas often have artifacts or overlapping shadows, and because of inadequate observation, they can be overlooked, leading to missed diagnoses. Missed diagnoses of the main bronchus or trachea occur because when there is no secondary lung pathology, these areas can be easily ignored. Thus, the common causes of missed diagnoses in chest DR are mostly human factors.
A flexibly positioned DR can realize multi-angle observation, thus reducing the misdiagnosis rate. Such as Perlove PLD7100A medical DR, it has a large range of suspension movement, and the bull’s head can be rotated at a full angle to realize the shooting without dead angle. Meanwhile, the bulb tube has a wide range of up and down elevation, which is convenient for the examination under the ankle weight-bearing condition in the standing position.
