MDCT is the most commonly used and accurate imaging modality for detecting and staging pancreatic tumors. It allows for assessment of the tumor as well as surrounding blood vessels. Studies show CT has a sensitivity of 77-85% and specificity of 81-82% for diagnosing vascular invasion which is important for determining resectability. Carefully timed contrast enhanced MDCT allows for comprehensive preoperative staging and assessment of local resectability of pancreatic carcinoma.

1. Essay Submitted in partial fulfillment of the M.Sc. Degree in
diagnostic radiology
BY
WALEED AHMED ABDO ALRAYIS
M.B.B.Ch

2. Prof. Dr. Tarek Mohammed
El Zayyat
Dr. Amr Ahmed Mostafa

5.  CT is the most commonly used imaging modality
for the detection and preoperative staging of
pancreatic tumors.
 21-55% of patients were incorrectly diagnosed as
having respectable tumor on CT only to be found
to have un-resectable tumor at surgery ,most often,
this type of misdiagnosis is due to undetected
vascular invasion , small Peritoneal implants, or
small hepatic metastases.
 MDCT facilitates the generation of multiplanar
reconstructions, such as curved planar
reformations, providing the potential to improve
the detection and staging of pancreatic tumors

13.  The term “pancreatic cancer” usually refers to
ductal adenocarcinoma. While this entity accounts
for 85% of primary pancreatic tumors, a variety of
other neoplasms can arise from the range of cell
types present in the normal pancreas (ducts, acini
and islets).

16.  Most patients do not develop symptoms until after the
cancer has metastasized.
 Common presenting symptoms epigastric pain,
unexplained weight loss, painless jaundice, light clay
colored stool, dark urine, pruritus, and Nausea.
 It represents about 85% to 90% of pancreatic tumors.
 Ductal adenocarcinomas are mainly located in the
head of the pancreas (60%), body of the pancreas
(13%), tail of the pancreas (5%) and diffuse
involvement (22%)

19.  Successful imaging detection of pancreatic
neoplasms is significantly improved by the use of
pancreas specific examination protocols.
 MDCT should be used whenever possible to
evaluate suspected pancreatic neoplasms because
it enables large volume coverage in short imaging
times.
 In the assessment of pancreatic tumors, there are
four basic components:
(a) detection of the pancreatic tumor;
(b) assessment of peripancreatic arteries;
(c) assessment of peripancreatic veins;
(d) detection of extra pancreatic metastases
(most frequently liver)

20.  Clinical Indications
 Patient Preparation
 Radiation Dose
 Contrast Material
 Acquisition Timing and Phases of Imaging:
 Reconstruction and post-processing imaging
modalities.

21.  All patients suspected of pancreatic neoplasm
 Acute pancreatitis
 Chronic pancreatitis
 Evaluation of jaundice
 Severe epigastric pain
 Recent onset of diabetes
 Weight loss

22.  Fast at least 6 hours before the examination.
 Spasmolytic drug to dilate duodenum and to
impair peristaltic contractions of the stomach and
duodenum.
 If spasmolytic is contraindicated the examination
may be performed while the patient remains in the
right lateral decubitus position.

23.  Assures the scanner will deliver the minimum dose
necessary to maintain the noise level in the images
that the user finds acceptable for diagnosis.
 Tube current modulation software can reduce
delivered dose by a factor of 30%.
 Patient radiation exposure decreases with
increasing numbers of detector rows due to
increased x-ray dose efficiency.

24.  Oral contrast material:
 Critical to delineate the bowel loops adjacent to the
pancreas and within the abdomen.
 Neutral contrast agent is preferable.
 Intravenous contrast material:
 Non-contrast enhanced studies are insufficient for
detection of neoplasms, evaluation of peripancreatic
vasculature or detection of distant metastases.
 Peak hepatic enhancement and peak pancreatic
parenchymal enhancement are directly related to the
injection rate.
 Peak hepatic enhancement and peak pancreatic
parenchymal enhancement are directly related to the
injection rate.

25.  A challenge of pancreatic imaging is that the timing of
peak pancreatic enhancement differs from that of
other organs in the abdomen, most notably the liver.
 Most radiologists employ a dual-phase protocol which
incorporates a pancreatic parenchymal phase and a
portal venous (hepatic parenchymal) phase
 A single-phase acquisition can be obtained with a 4-
detector row scanner if careful scan timing is used.

26.  Scan timing can be determined with two methods:
A. Automatic pumping
B. Bolus tracking technique

27.  Other concept in pancreatic imaging says that
contrast-enhanced imaging of the pancreas is
performed in three distinct phases:
 The early arterial phase
 Delayed arterial phase or the pancreatic phase
 Portal venous phase.

28.  Axial images
 Multiplanar Reconstruction
 Curved Multiplanar Reconstruction
 Maximum Intensity Projection
 Volume Rendering Technique

29.  Current criteria for resectability include
 Absence of distant metastases.
 Lack of evidence of tumor involvement of major arteries.
 If there is venous invasion suitable segment of portal
vein (above) and superior mesenteric vein (below) the
site of venous involvement to allow for venous
reconstruction.

30. Category Description Comment
Grade 0 No contiguity of tumor with a vessel Vascular invasion in 0% of
cases
Grade 1 Tumor contiguous with <25% of the Vascular invasion in 0% of
circumference of a vessel cases
Grade 2 Tumor contiguous with 25–50% of the Vascular invasion in 57% of
circumference of a vessel cases
Grade 3 Tumor contiguous with 50–75% of the Vascular invasion in 88% of
circumference of a vessel cases
Grade 4 Tumor contiguous with >75% of the Vascular invasion in all cases
circumference of a vessel or any vessel
constriction

32. Category Description Comment
Type A Fat plane separates the tumor Overall resection rate: 100%. Resection rate
and/or the normal pancreatic without venous resection: 95%. Conclusion:
parenchyma from adjacent ‘‘Lesions with type A and B appearances are
vessels likely to be resectable lesions’’
Type B Normal parenchyma separates Overall resection rate: 100%. Resection rate
the hypo dense tumor from without venous resection: 95%. Conclusion:
adjacent vessels ‘‘Lesions with type A and B appearances are
likely to be resectable lesions’’
Type C Hypo dense tumor is Overall resection rate: 89%. Resection rate
inseparable from adjacent without venous resection: 55%. Conclusion:
vessels, and the points of ‘‘Lesions of type C vascular involvement
contact form a convexity should be operated on with an intention to
against the vessels resect the tumor, but the tumor may or may
not adhere to the wall of the vessels’’
Type D Hypo dense tumor is Overall resection rate: 47%. Resection rate
inseparable from adjacent without venous resection: 7%. Conclusion:
vessels, and the points of ‘‘Lesions of type D vascular involvement
contact form a concavity would require pancreatic resection with a plan
against the vessels or partially to perform venous resection and venous graft
encircle the vessels or patch or would be unresectable for
surgeons who do not have that appearance’
Type E Hypo dense tumor encircles Overall resection rate: 0%. Resection rate
adjacent vessels, and no fat with outvenous resection: 0%. Conclusion:
plane is identified between the ‘‘Lesions of the type E and F vascular
tumor and the vessels involvement are not likely to be resectable’’
Type F Tumor occludes the vessels Overall resection rate: 0%. Resection rate
without venous resection: 0%. Conclusion:
‘‘Lesions of the type E and F vascular
involvement are not likely to be resectable’’

34. Category Description Comment
Grade 0 Normal, with a fat plane or 100% resectable
normal pancreas between the
tumor and the vessel
Grade 1 Loss of fat plane between the 100% resectable
tumor and the vessel, with or
without smooth displacement of
the vessel
Grade 2 Flattening or slight irregularity 92 % resectable
of one side of the vessel
Grade 3 Encased vessel with tumor The recommended threshold for
extending around at least two predicting vascular invasion. In this
sides (two-thirds of the study, resection was performed in1 of
perimeter), altering its contour 10 patients with grade 3 findings, but
and producing concentric or tumor along per vascular neural
eccentric narrowing of the bundles was present at resection
lumen margins.
Grade 4 Occluded vessel No attempted surgery

40.  Assessment of vascular invasion is an important
parameter for determining resectability of pancreatic
cancer.
 The introduction of MDCT and real-time 3D volume-
rendering software has greatly improved the
visualization of the pancreas and adjacent vasculature.
 An examination protocol should provide maximal
differentiation between normal and abnormal tissue.
 From the point of view of the detection of vascular
invasion, many studies have evaluated CT.

41.  In a study by Wen Yi Zhao et al, The pooled sensitivity
and specificity of CT in diagnosing vascular invasion
were 77% and 81%. Since CT technology improved in
different periods, in the recent five years (2004-2008)
CT has shown a higher diagnostic accuracy, and the
pooled sensitivity and specificity increased to 85% and
82%, respectively.
 Subgroup analysis of CT studies was made to
determine the involvement of different vessels, and the
pooled sensitivities for the invasion of the venous
system, portal vein, and arterial system were 75%, 75%,
and 68%, and the pooled specificities were 84%, 91%,
and 92%, respectively. For CT imaging with vascular
reconstruction, the pooled sensitivity and specificity
were 84% and 85%, higher than the estimates in
studies without reconstruction.

43.  Thin-sections MDCT is an accurate technique for
the diagnosis and assessment of the resectability
in patient with a suspected pancreatic neoplasm.
 The advantages of multidetector volumetric CT allow
comprehensive preoperative assessment of pancreatic
carcinoma. Carefully- timed scan acquisition
maximizes the difference in attenuation between the
neoplasm and the pancreatic parenchyma and allows
accurate staging as well as assessment of local
resectability

45.  In conclusion the MDCT technique remains the
first-line imaging modality in the evaluation of the
majority of patients with suspected pancreatic
disease because of low cost, greater widely used and
easy technical approaches and its great value in
staging pancreatic masses and predicting vascular
invasion which helps in choosing the appropriate
management for each case.