Blunt left diaphragmatic rupture: radiography and CT findings

Clinical History

A 25-year-old motorcyclist run over by a car was admitted to our hospital.

Imaging Findings

A chest X-ray and a subsequent thorax-abdomen CT scan were performed. Chest radiograph showed elevation and obscuration of the left hemidiaphragm with mediastinal shift. A nasogastric tube was seen in the thoracic cavity (arrowheads, Fig.1). CT showed a defect in the continuity of the anterolateral left hemidiaphragm (white arrows, Fig.2b) in with intrathoracic herniation fo the stomach, seen more clearly on reformatted images.

Discussion

The majority of traumatic diaphragmatic hernias usually occur in young adults after a blunt trauma². Injuries to the left hemidiaphragm are more frequent, and usually involve the posterolateral aspect of the hemidiaphragm³. Prompt recognition of a diaphragmatic rupture still poses a significant clinical and radiological challenge.Chest radiography remains the initial screening tool⁴. The specific diagnostic findings of diaphragamatic tears on chest radiographs include intrathoracic herniation of hollow viscus and visualization of a nasogastric tube above the hemidiaphragm, although concurrent pulmonary abnormalities related to the trauma can mask these signs¹. A helical CT scan has a sensitivity of 71% and a specificity of 100% in the detection of a diaphragmatic injuries¹. Findings suggestive of hemidiaphragmatic tears include: direct discontinuity of the hemidiaphragm (the most sensitive sign); intrathoracic herniation of abdominal contents; the collar sign, a waistlike constriction of the herniating hollow viscus at the site of the tear; and the dependent viscera sign¹, meaning that herniated viscera fall to a dependent position against the posterior ribs, since they are no longer supported posteriorly by the injured diaphragm. This latter sign represents an early indicator of diaphragmatic tear before visceral herniation can be confidently diagnosed². The recent trend towards nonoperative management of stable patients with blunt hepatic and splenic injuries may result in diagnostic delays of concomitant diaphragmatic injuries². Since cross-sectional imaging is routinely used to screen for internal injuries after blunt trauma, the knowledge of the above described signs is essential for an early detection of diaphragmatic tears that otherwise may have been detected at surgery for concomitant lesions.

Differential Diagnosis List

Final Diagnosis

Blunt left diaphragmatic tear,10 cm long with herniation of the stomach.

URL:	https://eurorad.org/case/2665
DOI:	10.1594/EURORAD/CASE.2665
ISSN:	1563-4086