Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Cardiac arrest
- Radiologic Findings
- The chest AP radiograph demonstrates diffuse ground glass opacity in the right lung and left upper lobe, suggestive lung contusion or pulmonary hemorrhage. Widening of upper mediastinum is also suspected.
On mediastinal settings of contrast enhanced chest CT, high density fluid collection is noted in the anterior mediastinum. The distal trachea and both main bronchi are not visualized. Therefore the possibility of mediastinal hematoma is suggested. In addition, dependent pooling of contrast and layering is seen in the azygos vein, hepatic/renal veins, within the dependent part of the IVC, the right heart chambers, and the hepatic/renal parenchyma,. There is no significant opacification of the left cardiac chambers and the aorta. These findings conclude cardiac arrest at the time of CT scan.
On the bone windows, fractures at both 1st ribs and manubrium are also seen.
- Brief Review
- Imaging a patient during a cardiac arrest is not a common occurrence. The imaging findings of sudden cardiac arrest during CT examination have been described in a few case reports only.
CT findings of cardiac arrest include dependent pooling and layering of contrast in the venous system, with faint or no opacification of the left sided cardiac chambers, aorta, and the abdominal organs. Injected contrast is seen layering in lumbar veins, hepatic and renal veins and parenchyma, and within the dependent part of the IVC and the right sided cardiac chambers. These findings can be explained by poor cardiac function, with failure to propel blood against gravity. If the heart stops pumping, the systemic arterial and venous pressures drop significantly, with loss of the arteriovenous pressure gradient. So the distribution of injected contrast material depends on the pressure with which the contrast is injected and the density of the contrast agent. Also the left sided cardiac chambers, aorta, and the abdominal organs are not well opacified by the contrast media.
The radiologist should be aware of the imaging findings so that any further imaging is discontinued and proper resuscitative measures can be taken immediately..
- References
- Roth C, Sneider M, Bogot N, Todd M, Cronin P. Dependent venous contrast pooling and layering: A sign of imminent cardiogenic shock. AJR 2006;186:1116–9.
Singh AK, Gervais D, Mueller P, Shirkhoda A, Sagar P, Mccarroll K. Cardiac arrest: Abdominal CT imaging features. Abdom Imaging. 2004;29:177–9.
Manisha Jana, Shivanand Ramachandra Gamanagatti, Atin Kumar. Case series: CT scan in cardiac arrest and imminent cardiogenic shock. Indian J Radiol Imaging. 2010;20(2):150–153.
- Keywords
- Lung, Vascular, Vascular,