Advantages and Values of Dynamic DR in Latent Rib Fracture Diagnosis
(Radiology Department of Zhangye Specialized Hospital for Reproductive Medicine, Zhangye, Gansu, 734000)
[Abstract] The rib fracture caused by a chest trauma is a common chest injury, and the traditional X-ray plain film is one of common examination methods for such a fracture. The latent rib fracture is a common fracture type, and the traditional X-ray examination has low accuracy with a high probability of misdiagnosis and missed diagnosis when used to diagnose such a fracture due to its complex anatomical structure and mild symptoms. A targeted safe examination method, dynamic digital DR, is used for diagnosis to ensure safety.
[Keywords] Latent rib fracture; imaging; dynamic diagnosis
[Chinese Library Classification Number] R445 [Document Code] A [Article ID] 2096-3807 (2019) 19-0148-03
1 General examination of latent fracture
The latent fracture means a fracture that is hard to be found or timely found through the routine X-ray examination, and can be found only after a period of time or by other imaging methods. The failure to timely diagnose such a fracture may delay treatment and affect the therapeutic effect, bringing avoidable mental and physical pain to the patient. The rib has a physiologico-anatomical structure. Its body is curved in an arch, and runs diagonally forward and downward from the posterior spine. From the perspective of imaging, chest ribs are divided into the part above the diaphragm and the part below the diaphragm. The ribs above the diaphragm overlap with the mediastinum, heart, ribs, pulmonary blood vessels and many other tissues and organs. The ribs below the diaphragm are affected by imaging factors of abdominal organs. The obtained images are often unclear due to a lack of natural contrast, causing that the latent rib fracture diagnosis is inaccurate and easy to miss. It is necessary to obtain the image of a fracture in the best position through turning-based high-definition large-format fluoroscopy for accurate positioning and qualitative diagnosis. Therefore, the diagnosis is difficult through traditional X-ray or static DR chest radiograph. If patients’ latent rib fractures are accompanied with subcutaneous emphysema, chest wall hematoma, pneumothorax, pleural effusion, etc., signs of rib fractures are very prone to be concealed, causing misdiagnosis and missed diagnosis. Some patients with rib fractures have minor traumas. The fractured end displacement is not obvious, and indirect signs are not significant, causing misdiagnosis and missed diagnosis.
Patent Mr. Kang, male, 29 years old, paid a visit to our hospital for a chest X-ray examination. Through the dynamic observation during turning, it was found that front ends of the 9th and 10th ribs of the left chest were fractured, the fractured end of the 9th rib was displaced, and the arc of the front end of the 10th rib was abnormal. The patient was diagnosed with fractures of the 9th and 10th ribs on the left (as shown in Figure 1). A detailed inquiry of the medical history showed that the patient once had a chest trauma 10 days ago and felt painful in the left hypochondrium due to the chest trauma. On the same day, a chest film was taken at a municipal hospital. The hospital found no abnormality through fluoroscopy by using a gastrointestinal machine (image intensifier) (as shown in Figure 2).
Figure 1: On the 10th day after the chest trauma, the patient paid a visit to our hospital for a chest X-ray examination. Under the dynamic DR fluoroscopy function of Angell Technology, it was found that front ends of the 9th and 10th ribs of the left chest were fractured. The patient was told to turn left and right for the dynamic observation so that real-time millisecond-level snapshots could be taken in a position where the fracture is obviously showed. (The arrow shows the fracture site).
Figure 2: This figure is a chest film taken in the other hospital on the day of the patient’s chest trauma, and there is no abnormality. (The image intensifier has a small shooting format, and its image definition and spatial resolution are lower than those of dynamic DR. When an image intensifier is used, the obtained images of ribs are not clear, and local shooting is not convenient for rib positioning.) The large-format images obtained through dynamic DR can clearly show the anatomical structure of the complete thorax, which is helpful for observing the overall state of the bony thorax, heart, lungs and diaphragmatic muscles under the respiratory movement.
Figure 3: This figure is a chest film taken in the other hospital on the 13rd day after the patient’s chest trauma, with a suspected rib fracture diagnosed.
Figure 4: The patient had a dynamic DR reexamination in our hospital on the 44th day after the chest trauma. The fractured ends of the 9th and 10th ribs of the left chest were well aligned and surrounded by annular calluses (as shown by the arrow in the figure above). In this case, the two hospitals use different imaging devices. According to the methods selected for several examinations and effects of chest films, it is not difficult to see differences in accurate disease diagnosis among different examination devices and methods used. In addition to the work experience of physicians of the Imaging Department, the used examination methods and devices as well as the quality of images also play an important role in ensuring the diagnosis correctness. The image intensifier has a small shooting format, and its image definition and spatial resolution are lower than those of dynamic DR. When an image intensifier is used, the obtained images of ribs are not clear, and local shooting is not convenient for rib positioning. The large-format images obtained through dynamic DR can clearly show the anatomical structure of the complete thorax, which is helpful for observing the overall state of the bony thorax, heart, lungs and diaphragmatic muscles under the respiratory movement. Dynamic images in different positions can be obtained by changing the examination position of the patient under the fluoroscopy function. Millisecond-level snapshots can be taken by selecting a position where the fracture is obviously showed, so as to effectively avoid misdiagnosis and missed diagnosis.
3 Advantages of dynamic digital DR in latent rib fracture diagnosis
(1) The large-format fluoroscopy images are convenient for observing the overall state of the complete bony thorax, heart, lungs and diaphragmatic muscles under the respiratory movement, helpful for rapid diagnosis by identifying the rib fracture site and location as well as the fracture type, complications, etc., and in particular, applicable to rapid treatment of emergency patients.
(2) The position of the patient can be changed under the fluoroscopy function to clearly show ribs that overlap with the mediastinum, heart, ribs, pulmonary blood vessels and many other tissues and organs, and are concealed due to complications such as subcutaneous emphysema, chest wall hematoma, pneumothorax and pleural effusion. Real-time millisecond-level snapshots are taken by selecting the best position for fracture imaging during turning to avoid misdiagnosis and missed diagnosis.
(3) The video saving/playback function of dynamic DR can completely record the entire fluoroscopic dynamic image, which is convenient for the repeated observation and analysis, instruction and teaching, multi-disciplinary consultation, and reduction of omissions.
(4) Dynamic DR is featured by high spatial resolution, clear images and high diagnosis accuracy. It effectively avoids avoidable mental and physical pain to the patient brought by misdiagnosis and missed diagnosis, as well as medical tangles incurred by this.
(5) Dynamic DR has a radiant quantity lower than that of the traditional X-ray examination method. It can effectively reduce radiation from the X-ray, and reduce the harm to medical personnel and patients.
X-ray radiography is the common method for diagnosing rib fractures. However, the direction of the X-ray is parallel to the running direction of ribs in the axilla section, and clear natural contrast is lacking in ribs below the diaphragm, causing that the chest radiography examination in a routine position has a high probability of misdiagnosis and missed diagnosis, which is adverse to timely treatment for patients. When a rib is incompletely fractured or is complete fractured but not obviously displaced, it may only be manifested as a slight uplift, depression, wrinkle or incomplete translucent line shadow or dense shadow on one side of the bone cortex, even sometimes only manifested as the abnormal running arc of the rib without visible fracture lines. Therefore, some extremely subtle fracture lines and incomplete fractures must be comprehensively considered by means of high-definition photography and dynamic turning-based fluoroscopy in a multi-angle and multi-position state in combination with clinical and imaging indirect signs. A targeted safe examination method, dynamic digital DR, is used for diagnosis to effectively reduce the probability of misdiagnosis and missed diagnosis of latent rib fracture symptoms and signs, so as to ensure safety.
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