AIIMS MCQ

Ans c

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. 

Portal Phase

Evaluate  for  hypovascular  liver  metastases 

Ref Blumgart 

The dedicated pancreas protocol uses 750 to 1000 mL of oral water as a negative contrast agent administered before the examination, to aid distinction of enhanced vessels from the
gastrointestinal tract

Blumgart page 345