Role of Imaging Methods in Diagnosis of Acute Pancreatitis Válek V. Radiologická klinika, FN Brno a LF MU v Brně.

Role of Imaging Methods in Role of Imaging Methods in Diagnosis of Acute PancreatitisDiagnosis of Acute Pancreatitis

Válek V.Válek V.Radiologická klinika, FN Brno a LF MU v BrněRadiologická klinika, FN Brno a LF MU v Brně

New Classification: New Classification: Acute PancreatitisAcute Pancreatitis

2007 revision of Atlanta classification and definitions2007 revision of Atlanta classification and definitions of of collections associated with acute pancreatitis by Acute collections associated with acute pancreatitis by Acute Pancreatitis Working Group.Pancreatitis Working Group.

Revised Definitions: Acute PancreatitisRevised Definitions: Acute Pancreatitis

Patients who present with two of the following three Patients who present with two of the following three manifestations are diagnosed as having acute pancreatitis: manifestations are diagnosed as having acute pancreatitis:

• Abdominal pain suggestive of pancreatic originAbdominal pain suggestive of pancreatic origin• Serum amylase, lipase ≥ 3 times normalSerum amylase, lipase ≥ 3 times normal• Characteristic findings on Characteristic findings on CECECTCT

Disease SeverityDisease Severity• First week based on clinical parametersFirst week based on clinical parameters • Thereafter on moThereafter on morrphologic parametersphologic parameters (CECT) (CECT)

Acute Pancreatitis Classification Working Group May 2007Acute Pancreatitis Classification Working Group May 2007

CECTCECT

Why CECT??Why CECT??

CT study is the most appropriate procedure to confirm CT study is the most appropriate procedure to confirm image findings of acute pancreatitis. image findings of acute pancreatitis.

The evaluation of severity The evaluation of severity (CTSI) (CTSI) is basic, because it is is basic, because it is strictly correlated to the prognosis of the patient. strictly correlated to the prognosis of the patient.

EEarly scanning for the prediction of severity is limited arly scanning for the prediction of severity is limited because the full extent of pancreatic necrosis may not because the full extent of pancreatic necrosis may not develop within the first 48 hour of presentation.develop within the first 48 hour of presentation. Dynamic Dynamic CECTCECT have have 80 – 90 % accurate for necrosis detection80 – 90 % accurate for necrosis detection..

Balthazar Radiology 1994; 193:297-306Balthazar Radiology 1994; 193:297-306Balthazar Radiology 2002; 223:603-613Balthazar Radiology 2002; 223:603-613

Accuracy of CTSI for predicting pancreatitisAccuracy of CTSI for predicting pancreatitis s severityeverity::

CTSI > 3CTSI > 3SensSensitivityitivity – – 11/1311/13SpecSpecificityificity – – 41/42 41/42 PPV PPV – – 11/1211/12NPV NPV – – 52/5552/55Accuracy Accuracy – – 52/5552/55

Gurleyik et al J Pancreas 2005; 6:562-567Gurleyik et al J Pancreas 2005; 6:562-567

CTSICTSI

MRIMRI

Acute pancreatitisAcute pancreatitis

The MR has actually a secondary role for the diagnosis, but The MR has actually a secondary role for the diagnosis, but it represents, first instance method in patients with adverse it represents, first instance method in patients with adverse reaction to contrast medium. reaction to contrast medium.

Standard MRI techniques including T1-weighted and T2-Standard MRI techniques including T1-weighted and T2-weighted fat-suppressed imaging sequences together with weighted fat-suppressed imaging sequences together with contrast-enhanced imagingcontrast-enhanced imaging..

CECT vesus MRCECT vesus MRNon-severe acute pancreatitisNon-severe acute pancreatitis

USUS

Acute pancreatitisAcute pancreatitis

The ultrasound can be used as first instance method in The ultrasound can be used as first instance method in patient with clinical suspect of acute pancreatitis. patient with clinical suspect of acute pancreatitis.

Contrast-enhanced ultrasound is a relatively new Contrast-enhanced ultrasound is a relatively new technique, currently used for liver tumors diagnosis. technique, currently used for liver tumors diagnosis. Contrast-enhanced ultrasound might represent a valuable Contrast-enhanced ultrasound might represent a valuable additional imaging method to contrast CT for selected additional imaging method to contrast CT for selected casescases..

Pulse inversion harmonic imaging allows the assessment Pulse inversion harmonic imaging allows the assessment of the necrotic areas in acute pancreatitis.of the necrotic areas in acute pancreatitis.

CECT versus USCECT versus US

Non-severe acute Non-severe acute pancreatitispancreatitis

Old term: Mild acute pancreatitisOld term: Mild acute pancreatitisNew Term: Non-severe acute pancreatitisNew Term: Non-severe acute pancreatitis

Histology:Histology:interstitial edema, micronecrosisinterstitial edema, micronecrosis

Clinical courseClinical courseno MSOF (Multisystem organ failure)no MSOF (Multisystem organ failure)improve in 48 – 72 hrimprove in 48 – 72 hr

ImagingImagingNone → CECTNone → CECTUS to evalUS to evaluateuate ggallstoneallstone

Old term: Mild acute pancreatitisOld term: Mild acute pancreatitisNew Term: Non-severe acute pancreatitisNew Term: Non-severe acute pancreatitis

Severe acute pancreatitisSevere acute pancreatitis

Old term: Severe acute pancreatitisOld term: Severe acute pancreatitisNew Term: Severe Acute PancreatitisNew Term: Severe Acute Pancreatitis

Pancreatic NecrosisPancreatic Necrosis

26/1226/12 5/15/1 17/117/1 6/46/4

1.1. One or more focal areas of nonenhancing pancreatic parenchymaOne or more focal areas of nonenhancing pancreatic parenchyma2.2. Focal parenchymal low signal in T1 FS unenhanced sequenceFocal parenchymal low signal in T1 FS unenhanced sequence3.3. Typically accompanied by gross peripancreatic fat necrosisTypically accompanied by gross peripancreatic fat necrosis4.4. MR mMR more heterogeneous than CTore heterogeneous than CT5.5. May not be apparent up to 48 hours after onset May not be apparent up to 48 hours after onset 6.6. Potential pitfalls:Potential pitfalls:

• Apparent diminished enhancement value in patients with Apparent diminished enhancement value in patients with normal fatty infiltrationnormal fatty infiltration

• Patients with diffuse parenchymal edema in less severe, Patients with diffuse parenchymal edema in less severe, interstitial pancreatitisinterstitial pancreatitis

• Small intrapancreatic focal fluid collectionsSmall intrapancreatic focal fluid collections

New Classification: Necrosis: Based on CECTNew Classification: Necrosis: Based on CECT or MR or MR

CECT vesus MR:CECT vesus MR:NecrosisNecrosis

Fluid CollectionsFluid Collections

1.1. Enzyme rich pancreatic juiceEnzyme rich pancreatic juice2.2. Acute peripancreatic fluid collection (APFC) (Acute peripancreatic fluid collection (APFC) (occur occur within 48 hrs within 48 hrs

in 30 – 50 %in 30 – 50 %, m, majority remain sterileajority remain sterile, r, resolves spontaneously esolves spontaneously within 2-4 weeks)within 2-4 weeks)

3.3. Post necrotic pancreatic fluid collections (PNPFC) Post necrotic pancreatic fluid collections (PNPFC) ((fluid and fluid and necrotic contentsnecrotic contents –fat, i –fat, initial necrosis → liquefactive necrosisnitial necrosis → liquefactive necrosis

4.4. Walled off pancreatic necrosis (WOPN) Walled off pancreatic necrosis (WOPN) = late stage of PNPFC= late stage of PNPFC

5.5. Pancreatic pseudocyst (4 weeks, contain Pancreatic pseudocyst (4 weeks, contain NONO necrosis) necrosis) 6.6. Pancreatic abscess = infected pseudocyst (dif.dg. Infected Pancreatic abscess = infected pseudocyst (dif.dg. Infected

PNPFC and infected WOPNPNPFC and infected WOPN

New Classification: Fluid collections: CECT or MRINew Classification: Fluid collections: CECT or MRI

Old term: Acute Fluid CollectionOld term: Acute Fluid CollectionNew Term: Post Necrotic Pancreatic Colections (PNPC)New Term: Post Necrotic Pancreatic Colections (PNPC)

Walled off necrosis (WON) Walled off necrosis (WON)

Old term: Pancreatic PseudocystOld term: Pancreatic PseudocystNew Term: Pancreatic PseudocystNew Term: Pancreatic Pseudocyst

Well circumscribed, thin walled, homogeneous low Well circumscribed, thin walled, homogeneous low attenuation collection of pancreatic juiceattenuation collection of pancreatic juice..

Requires 4 weeks, contains no necrosisRequires 4 weeks, contains no necrosisResolves spontaneously within 6 weeks 40%, 80% if <6cmResolves spontaneously within 6 weeks 40%, 80% if <6cm

Ductal communication Ductal communication – – impimportanortant for managementt for management

Noninfected or infected (suppurative)Noninfected or infected (suppurative)

Pancreatic Pseudocyst - CECTPancreatic Pseudocyst - CECT

Infected PseudocystInfected Pseudocyst

Old term: Pancreatic AbscesOld term: Pancreatic AbscesNew Term: Infected PseudocystNew Term: Infected Pseudocyst

Wall thicker, more irregular than the well delineated thin Wall thicker, more irregular than the well delineated thin wall wall ccircumscribed collection of pus near pancreasircumscribed collection of pus near pancreas with with hhomogeneously low attenuation centeromogeneously low attenuation center..

Requires 4 weeks to formRequires 4 weeks to form

Contains little or no necrosisContains little or no necrosis

Should be differentiated from infected PNPC and infected Should be differentiated from infected PNPC and infected WON WON

Infected Pseudocyst - CECTInfected Pseudocyst - CECT

ConclusionConclusion

1.1. Early diagnosisEarly diagnosis2.2. Staging (grading) + classification Staging (grading) + classification 3.3. Differential diagnosisDifferential diagnosis4.4. Follow-up (treatment)Follow-up (treatment)

Role of Imaging Methods in Diagnosis of Acute PancreatitisRole of Imaging Methods in Diagnosis of Acute Pancreatitis

CECECTCT = gold standard = gold standard

1.1. Reliable methodReliable method2.2. Widely availableWidely available3.3. Show local extend of inflammation/necrosis and Show local extend of inflammation/necrosis and

occurrence of complicationsoccurrence of complications4.4. Balthazar CTSI – based on grade of pancreatitis and Balthazar CTSI – based on grade of pancreatitis and

amount of glandular necrosisamount of glandular necrosis5.5. CTSI of 7 – 10 associated with 92% morbidity, 17% CTSI of 7 – 10 associated with 92% morbidity, 17%

mortalitymortality6.6. Pts with CTSI ≤3 can safely be discharged from ICUPts with CTSI ≤3 can safely be discharged from ICU

Vriens et all, J.Am.Coll.Surgery, 2005, 2001, 491 – 502Vriens et all, J.Am.Coll.Surgery, 2005, 2001, 491 – 502Che et al, Eur.J.Radiol., 2006, 57, 102 – 107Che et al, Eur.J.Radiol., 2006, 57, 102 – 107Leung et al, World J. Gastroenterol., 2005, 11, 6049 - 6052Leung et al, World J. Gastroenterol., 2005, 11, 6049 - 6052

1.1. Geographic areas of altered T1 signal correspond to Geographic areas of altered T1 signal correspond to areas of pancreatic necrosis depicted on CECTareas of pancreatic necrosis depicted on CECT

2.2. High signal intensity on unenhanced T1 FS SGE High signal intensity on unenhanced T1 FS SGE images corresponds to hemorrhage and correlates with images corresponds to hemorrhage and correlates with severity.severity.

3.3. Sensitivity of MRI for acute pancreatitis may surpass Sensitivity of MRI for acute pancreatitis may surpass CT (minor peripanc. inflamm) on T2 FS imagesCT (minor peripanc. inflamm) on T2 FS images

4.4. MRSI =CTSI using dynamic 3DT1 SGE gado enhanced MRSI =CTSI using dynamic 3DT1 SGE gado enhanced images, with added benefit of PD duct eval. Using images, with added benefit of PD duct eval. Using secretin MRCP.secretin MRCP.

5.5. PD duct evaluation using secretin MRCPPD duct evaluation using secretin MRCPLecesne et al Radiology 1999; 211:727-735Lecesne et al Radiology 1999; 211:727-735Pamuklar Magn Reson Clin NA 2005; 13:313-330Pamuklar Magn Reson Clin NA 2005; 13:313-330Arvanitakis Gastroenterology 2004; 126:715-723Arvanitakis Gastroenterology 2004; 126:715-723

MRI MRI = second choice= second choice

QuizQuiz

1.1. Pancreatic atrophy Pancreatic atrophy 2.2. Acute pancreatitisAcute pancreatitis 3.3. Von Wildelmuth diseaseVon Wildelmuth disease4.4. Pancreatic agenesisPancreatic agenesis5.5. Cystic fibrosisCystic fibrosis

Diagnosis??Diagnosis??

Cystic fibrosis is a condition with autosomal recessive Cystic fibrosis is a condition with autosomal recessive inheritance in which there are defects of serous and mucous inheritance in which there are defects of serous and mucous secretion involving multiple organs; 85 secretion involving multiple organs; 85 % % of patients have of patients have severe exocrine pancreatic insufficiency and steatorrhoea. severe exocrine pancreatic insufficiency and steatorrhoea. Obstruction of the main pancreatic duct and side branches Obstruction of the main pancreatic duct and side branches by inspissated secretions results in acinar and ductal by inspissated secretions results in acinar and ductal dilatation and subsequent atrophy of the acinar tissue. dilatation and subsequent atrophy of the acinar tissue. Ultrasound (US), computed tomography (CT) and pancreatic Ultrasound (US), computed tomography (CT) and pancreatic duct imaging may show abnormalities, duct imaging may show abnormalities, including marked including marked fatty replacement of the normal pancreatic parenchymafatty replacement of the normal pancreatic parenchyma, , dystrophic calcification and pancreatic cysts resulting from dystrophic calcification and pancreatic cysts resulting from ductal obstruction.ductal obstruction.

Cystic fibrosisCystic fibrosis

1.1. Pancreastic pseudocystsPancreastic pseudocysts2.2. Pancreatic polycystosisPancreatic polycystosis3.3. Hippel-LindauHippel-Lindau4.4. Chronic pancreatitisChronic pancreatitis5.5. Multiple cystic tumorsMultiple cystic tumors

Diagnosis??Diagnosis??

Von Hippel–Lindau disease is inherited as an autosomalVon Hippel–Lindau disease is inherited as an autosomalddominant condition characterized by renal cell carcinomas,ominant condition characterized by renal cell carcinomas,phaeochromocytomas, retinal angiomatosis andphaeochromocytomas, retinal angiomatosis andhaemangioblastomas of the cerebellum. The most commonhaemangioblastomas of the cerebellum. The most commonpancreatic lesions in this condition are simple pancreaticpancreatic lesions in this condition are simple pancreaticcysts, but serous cystic pancreatic neoplasms andcysts, but serous cystic pancreatic neoplasms andpancreatic islet cell tumours may also occurpancreatic islet cell tumours may also occur..

Von Hippel-LindauVon Hippel-Lindau

1.1. IPMN IPMN 2.2. AdenocarcinomaAdenocarcinoma3.3. Mucinous cystic tumorMucinous cystic tumor4.4. Serous cystic tumor Serous cystic tumor 5.5. PseudocystPseudocyst

Diagnosis??Diagnosis??

A serous cystadenoma consists of inumerable tiny cystsA serous cystadenoma consists of inumerable tiny cystsmeasuring less than 2 cm in diameter. Larger cysts occurmeasuring less than 2 cm in diameter. Larger cysts occurin the periphery of the tumor. The cysts are lined within the periphery of the tumor. The cysts are lined withsmall cuboid epithelial cells containing glycogen but nosmall cuboid epithelial cells containing glycogen but nomucin. The serous (microcystic) cystadenomas aremucin. The serous (microcystic) cystadenomas areusually large at diagnosis, often measuring more than 8usually large at diagnosis, often measuring more than 8cm across. The central fibrous area is hypervascularcm across. The central fibrous area is hypervasculardue to a rich subepithelial capillary network, causingdue to a rich subepithelial capillary network, causingenhancement to occur after intravenous contrast injectionenhancement to occur after intravenous contrast injectionat computed tomography and magnetic resonanceat computed tomography and magnetic resonanceimaging . Calcification occurs in the central fibrousimaging . Calcification occurs in the central fibroustissue in about half of patients.tissue in about half of patients.

Serous cystadenomaSerous cystadenoma