Q26 ) Ideal time for CECT in severe acute pancreatitis is
A. After 72 hours
B. After 48 hours
C. 24 hours
D. At admission
Q27) All are true about pancreatic protocol CT except (AIIMS 2012)
a) > 90% unresectable lesions picked up by CT
b) Dual phase CT with cuts taken at 40 secs and 70 secs
c) Liver metastasis detected in early arterial phase
After 72 hours
Mild acute pancreatitis
- enlargement of the pancreas with loss of definition of the borders of the pancreas.
- Thickening of the right or left anterior pararenal fascia
Severe Acute pancreatitis
Main determinant of clinical outcome is the degree of systemic organ disturbance, particularly during the early hours and days after admission to hospital
More than half of all deaths in AP occur within the first 2 weeks of illness and are usually a consequence
of multiple organ failure
The revised Atlanta Classification
3 grades of severity of pancreatitis:
Mild AP—characterized by the absence of organ failure or local
Moderately severe AP—defined by the presence of transient organ failure (resolving within 48 hours) or local complications developing in the absence of organ failure
Severe AP—defined by the presence of persistent organ failure
(>48 hours) with or without local complications
Since the diagnosis of acute pancreatitis is usually made on clinical and laboratory findings, an early CT is only recommended when the diagnosis is uncertain, or in case of suspected early complications such as bowel perforation or ischemia.
An early CT may be misleading regarding the morphologic severity of the pancreatitis, because it may underestimate the presence and amount of necrosis.
Pancreatic protocol CT involves imaging at the pancreatic phase (i.e., approximately 45 seconds after contrast administration) and at the portal venous phase (i.e., approximately 70 seconds after contrast administration). It is useful for detection of adenocarcinoma of pancreas.
Metastatic lesions are seen in the portal venous phase, because the lesions are not typically well vascularized.
Arterial phase images are principally used to distinguish metastatic disease from benign vascular lesions, such as hemangiomas, or to better define the arterial anatomy of the liver.
Non contrast phase used for
Evaluation of pancreatic calcifications and allows localization of the precise levels for imaging on the post contrast study.
Early arterial phase
Evaluation of pancreatic vasculature without interference from venous opacification.
Late Arterial Phase
Distinguish pancreatic neoplasms from adjacent normal pancreatic tissue It also is useful to evaluate hypervascular liver metastases as seen in patients with neuroendocrine tumors of the pancreas.
Evaluate for hypovascular liver metastases