Secretin-Assisted Computed Tomography Scan and Magnetic Resonance Imaging in Improving Pancreatic Tumor Conspicuity
Secretin-Assisted Computed Tomography Scan and Magnetic Resonance Imaging in Improving Pancreatic Tumor Conspicuity
Accurate preoperative tumor detection and staging are fundamental for treating patients with
 pancreatic adenocarcinoma. Patients with unresectable tumors can benefit from being spared an
 extensive operation associated with substantial morbidity and mortality, cost, and pain. On
 the other hand, patients with localized disease, which is amenable to surgical removal, have
 the option of operation. Therefore, accurate staging of pancreatic cancer requires the
 detection of the tumor, and evaluation of its size, its relationship to major peri-pancreatic
 vascular structures and portal venous system, locoregional lymph nodes, and distant
 metastases. Multiple imaging techniques have been used to evaluate the pancreas. Although, at
 this point, no consensus exists as to the best staging algorithm, multidetector (MD) computed
 tomogrophy (CT) and Magnetic resonance imaging (MRI) provide sufficient information for the
 management of most patients.

 Patients with a tumor larger than 3 cm are characterized as non-surgical. CT sensitivity in
 detecting small pancreatic tumors of less than 2 cm is low. Multiple methods have been
 suggested to increase the sensitivity of CT. The sensitivity of CT increases with using
 multidetector CT which now has an accuracy rate of about 95-97% for initial detection and
 approximating that of 100% for staging.

 Secretin (a natural hormone produced by the duodenal mucosal cells) is known to increase
 blood flow to the pancreas. The principal use of secretin in imaging today is in exocrine
 function of the pancreas or morphological evaluation of the pancreatic duct under ultrasound
 or MRI. Theoretically, pancreatic contrast enhancement should also increase after secretin
 administration. This would imply that tumor conspicuity might also be increased if contrast
 enhancement of the normal pancreas increases. Secretin CT has been advocated by other centers
 to improve depiction of the ampulla and periampullary/duodenal diseases and to improve
 contrast enhancement. O'Connell et al, used secretin in patients suspected or with known
 pancreatic mass and concluded that administration of intravenous secretin leads to greater
 enhancement of the pancreas with greater tumor conspicuity, than imaging without secretin.

 MRI of the pancreas has undergone a major change because it can provide noninvasive images of
 the pancreatic ducts and the parenchyma. MR cholangiopancreatography (MRCP) enables detection
 of anatomic variants such as pancreas divisum. Although contrast material-enhanced CT is
 still considered the gold standard in acute pancreatitis and for the detection of
 calcifications in chronic pancreatitis, MR imaging and secretin-enhanced MRCP are useful in
 evaluating pseudocysts and pancreatic disruption.

 The role of MR is still debated in pancreatic neoplasms except the cystic lesions where MR
 imaging provides critical information regarding the lesion's content and a possible
 communication with the pancreatic ducts. Although some articles have shown that MRI was
 equivalent to CT in diagnosis and staging, others have shown the opposite. Nishiharu et al.
 found comparable tumor detection but a benefit with CT, notably for peripancreatic and
 vascular invasion. Comparing CT, echoendoscopy, and MRI, Soriano et al. demonstrated that CT
 showed the highest level of precision in primary tumor staging, local-regional staging,
 vascular invasion, distant metastases, Tumor, node, metastasis (TNM) staging, and tumor
 resectability. MRI retains its originality in imaging the parenchyma, the pancreatic and
 biliary ducts, and vascular structures; however, in many institutions, CT remains the
 reference imaging choice for diagnosing and staging pancreatic cancer. Other than CT's
 advantages for the tumor, its excellent spatial resolution also provides detailed
 reconstructions in all planes and arterial mapping and therefore makes it possible to search
 for surgical contraindications such as celiac trunk stenosis. MRI is still used today as a
 second-intention tool when there is doubt or when CT and echoendoscopy are not sufficiently
 conclusive; it is not currently recommended to use MRI in first-intention diagnosis of
 pancreatic cancer.

 The aim of this pilot study is to determine whether the administration of intravenous
 secretin before contrast-enhanced CT and MRI improves pancreatic enhancement and pancreatic
 tumor conspicuity and to evaluate which technique is more appropriate for pancreatic tumor
 detection, staging and evaluation of resectability.
Inclusion Criteria:

 1. Patients 18 or above will be included in the study.

 2. Patients suspected of pancreatic mass or with a known pancreatic mass would be
 enrolled in the study.

 3. Patients with suspected pancreatic pathology and scheduled for imaging study (CT vs.
 MRI) will be included if they had obstructive jaundice, with either a stricture in the
 lower common bile duct on magnetic resonance cholangiopancreatography (MRCP) or a
 pancreatic mass on ultrasound or other imaging study.

 Exclusion Criteria:

 1. Patients with known advanced pancreatic tumors and those with previous pancreatic
 resection will be excluded.

 2. Patients with renal insufficiency: increase Cr level or glomerular filteration rate
 (GFR) of less than 45 ml/min/1.73.

 3. Patients who demonstrate increase in Cr level or patients with acute renal injury.

 4. Claustrophobic or patients who are not able to tolerate MRI.

 5. Patients with previous history of contrast allergies.

 6. Pregnant patients