Chest CT examinations in patients presenting with acute chest pain: a pictorial review

Extended-FAST plus MDCT in pneumothorax diagnosis of major trauma: time to revisit ATLS imaging approach?

BACKGROUND AND OBJECTIVE

Pneumothorax (PNX) detection is of the utmost clinical relevance because it may quickly progress to cause hemodynamic instability as a consequence of invasive ventilation. Radiography is characterized by a low sensitivity to detect this disease; in recent years, chest ultrasound (US) has gained increased visibility in the diagnosis of acute respiratory emergencies including PNX. The aim of this retrospective study was to evaluate the clinical impact of extended focused assessment with sonography in trauma (E-FAST) during the past 6 years of experience with this technique in our Level I trauma center.

METHODS

Between January 2013 and December 2018, we performed a retrospective case-series study including 3320 consecutive patients admitted to the emergency department of our hospital because of major trauma. Extended-US was always performed and reported immediately after FAST during primary survey and before multidetector computed tomography (MDCT) scans. The presence of PNX was determined using the well-known accepted US criteria. US findings were compared with computed tomography (CT) findings, the reference standard for PNX detection.

RESULTS

Of the 6640 lungs observed with E-FAST, there were 1244 PNX cases, while 1328 PNX cases were detected either on the basis of MDCT or on the basis of the presence of air flush during the thoracic decompression in the emergency room. Among the 84 false negatives, 12 patients had subcutaneous emphysema, 38 had a body mass index higher than 27, 6 had a thoracic wall hematoma, and 4 had chest penetrating trauma. There were 10 false positives in the diagnosis of PNX at US examination, with mild extension and not clinically significant. The overall sensitivity of E-FAST for PNX detection was 93.6% (1244/1328), the specificity of E-FAST was 99.8% (5312/5322), the negative predictive value (NPV) was 98.4% (5312/5396), and the positive predictive value (PPV) was 99.2% (1328/1338).

CONCLUSION

Our results demonstrate that bedside thoracic US is characterized by a very good accuracy in the diagnostic work-up of major trauma patients, even in difficult conditions, allowing rapid diagnosis of PNX.

ADVANCES IN KNOWLEDGE

The novelty of this research lies in the possibility of diagnosing potential life-threatening conditions in a very short time by means of US, thus proposing a revision of the Advanced Trauma Life Support (ATLS) guidelines in order to incorporate it in the work-up of high-energy injured patients.

Multislice spiral CT angiography for evaluation of acute aortic syndrome

OBJECTIVE

To discuss the diagnostic value of multislice CT angiography (MSCTA) in acute aortic syndrome (AAS).

MATERIALS AND METHODS

The clinical and imaging data of 36 cases diagnosed as AAS by MSCTA were collected. The manifestations of the MSCTA images were reviewed retrospectively, and the average x-ray dose was calculated.

RESULTS

Among 36 AAS cases, 16 cases had aortic dissection (AD), 8 cases had penetrating atherosclerotic ulcer (PAU), 7 cases had intramural hematoma (IMH), and 5 cases had unstable thoracic aneurysm (UTA). Of 16 cases with AD, type A and type B accounted for 43.7% (7/16) and 56.3% (9/16), respectively. Of 7 cases with IMH, type A and type B accounted for 42.9% (3/7) and 57.1% (4/7), respectively.

CONCLUSION

In spite of the x-ray radiation, MSCTA proves to be a rapid and noninvasive imaging technique for the diagnosis of AAS.

Diagnostic Imaging in pediatric thoracic trauma

Thoracic trauma accounts for approximately 14% of blunt force traumatic deaths, second only to head injuries. Chest trauma can be blunt (90% of cases) or penetrating. In young patients, between 60 and 80% of chest injuries result from blunt trauma, with over half as a consequence of impact with motor vehicles, whereas in adolescents and adults, penetrating trauma has a statistically more prominent role. Pulmonary contusions and rib fractures are the most frequent injuries occurring. Chest X-ray is the first imaging modality of choice to identify patients presenting with life-threatening conditions (i.e., tension pneumothorax, huge hemothorax, and mediastinal hematoma) and those who require a CT examination. Multi-Slice Computed Tomography is the gold standard to evaluate chest injuries. In fact, the high spatial resolution, along with multiplanar reformation and three-dimensional (3D) reconstructions, makes MDCT the ideal imaging method to recognize several chest injuries such as rib fractures, pneumothorax, hemothorax, lung contusions and lacerations, diaphragmatic rupture, and aortic injuries. Nevertheless, when imaging a young patient, one should always keep into account the ALARA concept, to balance an appropriate and low-dose technique with imaging quality and to reduce the amount of ionizing radiation exposure. According to this concept, in the recent years, the current trends in pediatric imaging support the rising use of alternative imaging modalities, such as US and MRI, to decrease radiation exposure and to answer specific clinical questions and during the observation period also. As an example, ultrasound is the first technique of choice for the diagnosis and treatment of pleural and pericardial effusion; its emerging indications include the evaluation of pneumothoraces, costocondral and rib fractures, and even pulmonary contusions.