Medical network - on April 20 

 

Background: 

 

Pediatric airway foreign bodies in airway obstruction of an emergency, is one of the most common pediatric emergency, a serious threat to children with life and health, if processing is not timely can cause severe complications, and even death. Pediatric airway foreign body check with X-ray, CT and bronchoscopy, including X-ray traumatic examination is the gold standard, is the first choice for pediatric airway foreign body check method. 

 

Literature reported that pediatric tracheal and bronchial foreign body X-ray misdiagnosed the missed diagnosis of up to 44.4%, and not of deeds chest X-ray and the lack of good deep breathe, breathe in chest radiograph is the main causes of misdiagnosis and the misdiagnosis. 

 

X-ray manifestations: 

 

Pediatric airway foreign body disease among children under the age of 3, there are many foreign body in history. For such children X-ray is often preferred. Negative foreign body in addition to the minority can be directly development, most by wild transparency to the lungs and mediastinal and diaphragmatic movement and position change, heart shadow inspiratory sex increases indirect signs such as diagnosis, here introduces three common X-ray manifestations. 

 

1. The bronchial foreign body 

 

Bronchial foreign body inevitably leads to the corresponding pulmonary ventilation disorder, on both sides of the chest cavity pressure imbalance and caused by abnormal mediastinum and diaphragmatic swing or position, will show the local lung field transparency change. So must do chest conventional perspective to observe mediastinum oscillation situation, and then with a deep breath and deep inspiratory phase perturbation, observe whether local lung field transparency abnormalities, such as sniffing sexual flapper blocking, breathe in the lateral lung wild transparency, mediastinum to lateral displacement, exhale recovery; Exhale and sexual flapper obstruction, breathes out of lung field enhanced transparency, to the contralateral mediastinum shift, inhale. So the author thinks that everyone who suspected children with bronchial foreign body should be regular chest X-ray and deep breathe, breathe in the sternum dynamic and static combination of diagnosis, the two are equally important in the diagnosis value, otherwise the misdiagnosis and appear easily misdiagnosed (as shown in figure 1, figure 2, figure 3). Especially in the early foreign body should be paid attention to breathe, breathe in sexual flapper block, the differential diagnosis of a correct tips for clinical treatment. 

 

2. The trachea 

 

In trachea clinical symptoms significantly, as a result of trachea foreign body can be moved up and down with the airflow, paroxysmal irritating cough, typical can smell in the neck, chest and slapping sound, reason often can make a diagnosis accordingly. Such foreign body incomplete obstruction is often blocked, less negative foreign body X-ray manifestation or mild, can only be found on the chest radiograph exhale both lungs transparency is higher, across low, perspective breathing lung transparency of two phase difference is small, diaphragmatic motion is abate, mediastinal no obvious oscillation. Sometimes only characterized by increased pulmonary texture, fuzzy, can be moved up and down of the foreign body of gas vessel injury is heavier, the trachea bronchial secretions increase, poor drainage. At this point to keep watch that is particularly important and is easy to miss the typical X-ray changes, namely the inspiratory phase abnormal heart shadow, expiratory phase abnormal heart shadow size, otherwise prone to misdiagnosis and misdiagnosis (as shown in figure 4). 

 

3. The subglottic foreign body 

 

Subglottic foreign body on the early symptoms of wheezing, wheezing, cough, hoarseness, transient violet purple, etc., in intermittent period often misdiagnosed because of the cough reflex is not obvious. Stay in the subglottic foreign body generally larger, lateral neck a little while due to air good contrast, whether positive or negative foreign bodies often can be developed. Smooth subglottic foreign body, in the early days because of less damage to the surrounding tissues, has not yet affected lung ventilation, X-ray chest radiography and fluoroscopy can show is normal, if not taken neck side slice can cause misdiagnosis. Reason for foreign body in history clear, lung auscultation and chest X-ray examination found no positive cases, also should consider to have a rest under the possibility of foreign body. Taken the neck side slice examination can not only show subglottic foreign body, also can show the neck section of endotracheal and the glottis, subglottic foreign body, can yet be regarded as a simple and important method for the diagnosis and differential diagnosis. 

 

 

Figure 1 right bronchial foreign body. Grates on the eyewinker afternoon, X-ray performance for lower lung field transparency slightly enhanced, every muscle on the right side is the left side is slightly lower. Only a chest X-ray taken and combined with the dynamic and static perspective observation leads to misdiagnosis. 

 

 

 

Figure 3, figure 2 right bronchial foreign body. Grates on the foreign body after months cough asthma, inspiratory phase (on) X-ray showed normal. Combining perspective to observe mediastinum swing, scene in expiratory phase (below), X-ray manifestation of mediastinal mental image to the left swing, high light transmittance wild is on the left side of the right lung, right diaphragmatic low, diagnosis right bronchial foreign body, avoid the misdiagnosis. 

 

 

Figure 4 in trachea. Grates on the day after foreign body, X-ray performance for both lungs texture slightly increased, under the two lung field enhanced transparency, the broadening gap. Perspective under the notice only without mediastinal swing, ignored the breathing lung transparency of two phase and diaphragmatic movement, leading to misdiagnosis for bronchial infection. 

 

Ordinary X-ray fluoroscopy and chest radiography clinical limitations: 

 

Common perspective image cannot record and repeat, diagnostic radiology doctors often for a long time still cannot be observed after continuous perspective all valuable diagnostic signs, this situation is more common in the low qualification physicians. Children or because of the shortness of breath breathing cycle shortened, or for young crying do not cooperate, physicians are often difficult to absorb ideal deep breathe, breathe in the sternum, has consumed the sternum often there is difficult to determine is the issue of inspiratory and expiratory phase. So, ordinary X-ray fluoroscopy and radiography in the diagnosis of pediatric airway foreign body in check the one-time success rate is low, the image quality is difficult to guarantee and the limitations of microscopic image is not easy to observe, repeat radiography and long time perspective not only children receive X-ray exposure is big, also the timing delay treatment. 

 

The advantages of dynamic DR: 

 

Aiming at these problems, for young children with foreign bodies in history, check the equipment selection dynamic DR, recumbent children to check on the bed, the first perspective with a respiratory cycle, dynamic observation of breathing exercises and mediastinal presence of oscillation (do careful observation can through the video playback). Then choose 2 frames a second mode of continuous points, continuous point 4 to 8, full records with a chest breathing cycle dynamic images. Because some speed, for children crying don't cooperate, need to parents on their shoulders and pelvis slightly restrictions can, does not affect the effect of radiography. Through looked back at the continuous point image of respiratory cycle, can according to the size of the children with thoracic accurately find the breath deep and deep expiratory phase contrast observation. Finally combining dynamic and static images, observe whether there is a local lung field in the process of breathing abnormal changes of transparency, mediastinum and horizontal movement and position of insulation abnormal changes, indirect signs such as increased heart shadow inspiratory sex to diagnosis. 

 

If lung auscultation and examination found no positive above, also should add the neck side slice, such as diagnosis for cervical trachea, subglottic foreign body. 

 

Conclusion: 

 

To sum up, for young children with foreign bodies in history, radiation physicians in the process of cooperate to clinical diagnosis, through dynamic DR continuous point won good deep breathe, breathe in the sternum, coupled with the perspective, basic can clear diagnosis, tracheal and bronchial foreign body. Should also be added in the absence of positive found cervical lateral slice, such as diagnosis for cervical trachea, subglottic foreign body. Diagnosis when combined with the dynamic and static performance of X line, according to the bronchus and trachea and sequence of subglottic gradually in diagnosis and differential diagnosis, the accuracy of the diagnosis of pediatric airway foreign bodies is greatly increased. 

 

Dynamic DR with traditional DR, modular gastrointestinal machine in pediatric airway foreign body check the advantage analysis: 

 

In pediatric airway foreign body check, the radiologist at face two problems: one is the conventional perspective image cannot record and repeat the question, the second is with difficulty grasping the deep breathe, breathe in the sternum, led to check the one-time success rate low, poor image quality, if repeated radiography and fluoroscopy is children with radiation increases, not repeat again easy to misdiagnosis and misdiagnosis. 

 

Using different X-ray equipment analysis the advantages and disadvantages are as follows: 

设备类型 临床需求	常规DR	组合式胃肠机	动态DR
胸部透视	不支持(易遗漏重要诊断征象，风险高)	支持(视频不可保存)+透视视野小 = 透视时间长+无法举证	支持(视频可保存回看)+透视视野大= 透视时间短+可举证
深呼、吸气相胸片	盲拍 (成功率低，难以分辨呼、吸气相，风险高)	连续点片+点片幅面小 (精准捕捉呼吸双向胸片，但胸部包含不全，可能要多次拍摄)	连续点片+点片幅面大 (精准捕捉呼吸双向胸片，一次拍摄即可获得最佳影像)
颈椎侧位片	效果好	效果好	效果好