Table 3 CT hypotension complex findings and frequency

Vascular signs

Flattening of the inferior vena cava

IVC flattening with anterior-posterior diameter < 9 mm in three consecutive segments, 20 mm above and below the renal veins and at the level of the perihepatic portion

77–100%

The halo sign

The presence of low-density fluid < 20 HU surrounding the IVC

77.8%

Small calibre aorta

A small-calibre abdominal aorta with anterior–posterior diameter < 13 mm detected 20 mm above and below the renal arteries

20–48%

Visceral sign

Shock bowel

Small bowel fluid-filled dilated loops with thickened walls (> 3 mm) due to oedema of the submucosa and increased mucosal enhancement relative to the psoas muscle

40–70%

Mucosal enhancement of the gallbladder

Mucosal enhancement, without thickened gallbladder walls

33.3%

Parenchymal signs

Peripancreatic oedema and abnormal pancreatic enhancement (shock pancreas)

Abnormal post-contrast higher attenuation than to normal density values (20 HU greater than the liver and spleen) often with peripancreatic low-density fluid (< 20 HU)

> 44%

Splenic hypoperfusion

Extremely decreased enhancement in contrast early CT phase

11–29.6%

Abnormal liver enhancement

A reduction of hepatic enhancement (25 HU less than the spleen)

4–11.1%

Abnormal renal enhancement

Increased and prolonged parenchymal enhancement

55.6%

Abnormal adrenal hyperenhancement (adrenal stress)

Bilateral hyperenhancement of the adrenal gland

> 60%

Abnormal thyroid enhancement (shock thyroid)

Heterogeneous contrast hyperenhancement, similar to a multinodular gland, with the presence of low-density fluid surrounding the thyroid (5–10 HU)

Not detected

Other sign

Ascites

Fluid collects in peritoneal spaces

Not detected