#Comet tail artifact portable#
Assigned radiologists reported both CT-scan and portable CXR results, while ultrasonography was performed by an ER specialist. Patients with ATLS guideline indi- cations underwent a chest CT-scan. An independent medical team performed the necessary procedures based on ATLS algo- rithms and the research assessments did not interfere with the patient’s care. It should be noted that the medical team responsible for the patient and the ER specialist who conducted the ultrasound were different. The disappearance of lung sliding and comet-tail artifacts in M-mode sonography used to detect pneumothorax and the hypo-echo area above the diaphragm and chest wall used to detect hemothorax were also considered. The ultrasound image of pleural effusion is characterized by an echo-free space be- tween the visceral and parietal pleura (Figure 2) (9). In contrast to the ra- diological method, ultrasonography allows an easy dif- ferentiation of loculated pleural liquid and thickened pleura and is efficient in pinpointing thoracocentesis, even in small fluid collections. Ultrasound allows the detection of small amounts of loculated pleural fluid in amounts as small as 20 ml, which cannot be identified by X-rays, as it is only capable of detecting volumes above 50 mL. Trapped air in the pleural space prevents visu- alization of lung sliding signs and comet-tail artifacts, therefore, based on these findings, pneumothorax can be detected with ultrasonography (5). Moreover, sharp resonance appears during ventilation at the border of the pleura and lung, which is called a comet-tail artifact ( Figure 1). This characteristic is also known as the gliding sign. In a normal lung view, pleural move- ment along the parietal and visceral sides is called lung sliding, which can be easily seen with ultrasound. Sonography images of the lung are built with air artifacts as the air stops the beam however, this artifact varies when it is in the pleural space. We used a General Electric E200 ultrasound with two types of probes namely: a curve probe of 5 MHz frequency for hemothorax assessment and a linear probe of 6.5-9 MHz frequency for pneumothorax assessment. The patients were evalu- ated according to the ATLS algorithm, and examination findings were recorded following initial evaluations, an emergency medicine specialist performed chest ultraso- nography to detect pneumothorax and hemothorax. Patients who underwent a tube thoracostomy, before they had an opportunity to have an ultrasound due to their un- stable clinical situation, or for any other reason, such as a lack of access to ultrasound at the time of admission, were excluded from the study. The examination findings included: chest pain, tenderness over the ribs, decreased lung sounds or chest percussion, subcutaneous emphysema, or any sign of trauma such as abrasions and/or bruises. The mechanisms of injury includ- ed car rollover, being thrown out of the vehicle, frontal impact, compression of the chest with the steering wheel or dashboard, severe side impact, fall, or acceleration- deceleration injury. We enrolled all patients with severe multiple trauma at triage ESI 1 and 2 levels, who were admitted to the emer- gency ward of Imam Reza Hospital, Tabriz, Iran during winter 2013 based on the mechanism of injury, or their history and examination findings of suspected chest inju- ries, and chest CT-scan according to an Advanced Trauma Life Support algorithm. Moreover, we aimed to include this method in a focused assessment with sonography for trauma (FAST) protocol to assess suspected cases of chest trauma.
Taking the limitations of portable CXR and CT-scans into account, the objectives of the present study were to determine the sensitivity and specificity of ultrasonog- raphy in detection of hemopneumothorax in patients with multiple trauma admitted to the emergency room. ultrasound has previously been introduced as an accurate method to detect pneumothorax (8) and he- mothorax (9), few published reports are available in Iran concerning evaluation of the sensitivity and specificity of ultrasonography in the diagnosis of pneumothorax and hemothorax in comparison with portable CXR and CT- Scan.