Transcript Clinical Signs and Characteristics of Pancreatitis

Clinical Signs and
Characteristics of Pancreatitis
July/August 2012 issue of Radiologic Technology.
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Objectives
• Describe the underlying physiologic alterations
that lead to acute and chronic pancreatitis.
• Summarize the clinical presentation of acute and
chronic pancreatitis.
• Explain the etiology, diagnosis, and medical
management of pancreatitis.
• Identify and distinguish the imaging
characteristics of pancreatitis as seen on
computed tomography and sonography.
Pancreas
The pancreas is a hard-working, 6- to 8-inch long,
tadpole-shaped glandular organ with complex
structures that perform vital functions.
The pancreas is most often found within the
midline of the upper abdomen in the epigastric
region
Acute Pancreatitis
The rapid onset of pancreatic inflammation is
referred to as acute pancreatitis, a common
disease with the potential for substantial
morbidity and mortality. It comprises a wide
range of diseases that vary from focal or diffuse
pancreatic edema to severe necrosis of the
gland.
Pathogenesis of Acute Pancreatitis
The pathogenesis of acute pancreatitis includes:
1.
The edema or obstruction of the ampulla of Vater by a biliary stone.
2.
The reflux of bile into the pancreatic duct from a faulty sphincter of
Oddi, subsequently leading to edema of the pancreas.
3.
A predisposing factor, such as genetic causes, that allows for the
premature activation of pancreatic enzymes.
Regardless of the origin, the chief mechanism for
the destruction of the gland is autodigestion of the
pancreatic tissue by inappropriately activated
pancreatic digestive enzymes.
Acute Pancreatitis: Clinical Assessment
Pancreatitis has a wide spectrum of clinical manifestations.
Acute abdominal pain is the hallmark of acute pancreatitis,
however abdominal pain may be mild to severe, making the
clinical manifestations unpredictable and somewhat vague.
Other clinical assessments include:
1.
Laboratory findings consistent with the diagnosis of acute pancreatitis
include an elevation in serum amylase and lipase (Amylase levels rise
first, typically within the first 24 hours from the disease onset, while
lipase levels increase within the first 72 to 96 hours.
2.
Physicians often use clinical scoring systems, such as the Ranson score to
assess the severity of the disease. A Ranson score takes into account the
patient’s age and many vital laboratory findings
Acute Pancreatitis: Imaging Assessment
When patients present with acute abdominal
pain, concerns multiply. Imaging often confirms
a diagnosis when pancreatitis is suspected
clinically. Although radiography and MR are
valuable, contrast-enhanced CT and sonography
are the most practical imaging modalities used
for diagnosing acute pancreatitis.
Computed Tomography
CT is used to assess the
pancreas when pancreatic
abnormalities are
suspected CT is superior to
other imaging modalities
because of the speed and
accuracy at which it can
provide high-resolution,
diagnostic information.
Ultrasonography
Ultrasonography often is used in screening the
acute abdomen. Patients who present with clinical
symptoms of pancreatic or biliary disease may be
offered a sonographic evaluation of the pancreas
before scheduling more expensive and invasive
procedures such as CT or ERCP.
Chronic Pancreatitis
Chronic pancreatitis can be a severely debilitating disease. It is
characterized by progressive destruction, cellular infiltration, and
irreversible fibrosis of the gland , with the latter being the hallmark
feature. Pathologically, chronic pancreatitis is apparent by the loss
of the exocrine pancreatic function.
Chronic pancreatitis causes the organ to undergo considerable
structural changes, including:
• Atrophy.
• Dilation or stricture of pancreatic duct segments.
• Calcification development within the parenchyma of the gland.
• Peripancreatic fluid collections.
• Alterations of peripancreatic fat.
Pathogenesis of Chronic Pancreatitis
Acute pancreatitis and chronic pancreatitis are
established as distinct diseases because not all
patients with acute pancreatitis develop the chronic
form of the disease.
There appear to be 2 contradictory theories as to
how fibrosis occurs within the organ. Despite the
debate, chronic pancreatitis is routinely depicted as
having either alcoholic- or nonalcoholic-related
causes
Chronic Pancreatitis: Clinical Assessment
Diagnosing chronic pancreatitis requires a clinical
and imaging approach. The diagnosis can be
difficult, and clinical features may be identical to
acute pancreatitis. Patients may present with
recurrent abdominal, back, or epigastric pain, with
other clinical features such as flatulence, weight
loss, anorexia, nausea, vomiting, and constipation.
Laboratory findings for chronic pancreatitis include an
elevation of amylase and lipase during attacks of acute
pancreatitis.
Chronic Pancreatitis: Imaging Assessment
As with acute pancreatitis, imaging is important
in the diagnosis and follow-up care of patients
with chronic pancreatitis. ERCP often serves a
dual purpose for chronic pancreatitis because it
is an outstanding imaging tool and
interventional instrument. ERCP is considered
the gold standard for diagnosing chronic
pancreatitis.
Conclusions
Although much clinical research exists, additional
research is needed to understand the intricacies of
acute and chronic pancreatitis. We know that the
pathogenesis of pancreatitis ultimately begins with
the activation of pancreatic enzymes, although how
these enzymes become active is unknown. Ultimately,
the autodigestion of the organ from these destructive
enzymes devastates normal pancreatic tissue and the
surrounding tissues of the abdomen, potentially
leading to irreparable distortions of anatomic
structures, necrosis, and fibrosis.
Discussion Questions
Thinking about the different options used to
image acute pancreatitis, what are the pros and
cons of each option?
What is the chief mechanism that causes the
destruction of the pancreas?
Two theories are present for the cause of
chronic pancreatitis, discuss the similarities and
difference for these two theories.
Additional Resources
Visit www.asrt.org/students to find information
and resources that will be valuable in your
radiologic technology education.