Table 3.

CT hypotension complex findings and frequency

CT hypoperfusion complex
Type	Sign	Definition	Incidence rate in patient with severe hypoperfusion*
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

*Literature data from post-traumatic hypoperfusion complex [26]