Final answer:
Agonal intestinal intussusception is a post-mortem artifact and lacks inflammation, whereas in vivo intussusception occurs during life and presents with clinical symptoms. Differentiation can be aided by imaging techniques and histological examination of tissues.
Step-by-step explanation:
To differentiate agonal intestinal intussusception from in vivo intussusception, it is important to understand both terms in a medical context. Agonal intussusception occurs around the time of death and is a result of the body's last movements. These are not true pathological findings but a post-mortem artifact, and typically, they lack the signs of inflammation that would indicate a living process.
On the other hand, in vivo intussusception takes place while the patient is still alive and presents with clinical symptoms such as abdominal pain, nausea, and possibly bloody stools. A key diagnostic method for in vivo intussusception is using imaging techniques like ultrasound or CT scan, which can show the characteristic 'telescoping' of the intestine. Histological examination postmortem can help to confirm agonal intussusception, where a lack of significant inflammation or hemorrhage will indicate that intussusception occurred perimortem or postmortem.