Upper Respiratory Tract Infections

Upper Respiratory Tract Infections
By:Dr. Meenakshi Aggarwal MD
Emory Family Medicine

Definition

* Inflammation of the respiratory mucosa from the nose to the lower respiratory tree, not including the alveoli.

Objectives
* List the various categories of upper respiratory tract infections
* Obtain a pertinent history in a patient with a suspected URI.
* Perform a targeted and thorough physical examination to confirm the diagnosis of URI.
* Perform and interpret selected tests to diagnose URI
* Manage and treat uncomplicated URI’s.

Categories
* Acute Rhinosinusitis
* Acute Pharyngitis
* Acute Bronchitis

Differential Diagnosis
* Influenza
* Pneumonia
* Tuberculosis
* Asthma

Anatomy of Sinuses
Acute Rhinosinusitis (Viral)
* Common Symptoms: Nasal discharge, nasal congestion, facial pressure, cough, fever, muscle aches, joint pains, sore throat with hoarseness.
* Symptoms resolve in 10-14 days
* Common in fall, winter and spring.
* Treatment: Symptomatic

Acute Bacterial Sinusitis
* Causative agents are usually the normal inhabitants of the respiratory tract.
* Common agents:

Streptococcus pneumoniae
Nontypeable Haemophilus Influenzae

Moraxella Catarrhalis
Signs and Symptoms
* Feeling of fullness and pressure over the involved sinuses, nasal congestion and purulent nasal discharge.
* Other associated symptoms: Sore throat, malaise, low grade fever, headache, toothache, cough > 1 week duration.
* Symptoms may last for more than 10-14 days.

Diagnosis
* Based on clinical signs and symptoms
* Physical Exam: Palpate over the sinuses, look for structural abnormalities like DNS.
* X-ray sinuses: not usually needed but may show cloudiness and air fluid levels
* Limited coronal CT are more sensitive to inflammatory changes and bone destruction

Ethmoid Sinusitis
Coronal computed tomographic scan showing ethmoidal polyps. Ethmoid opacity is total as a result of nasal polyps, with a secondary fluid level in the left maxillary antrum.

Treatment
* About 2/3rd of patients will improve without treatment in 2 weeks.
* Antibiotics: Reserved for patients who have symptoms for more than 10 days or who experience worsening symptoms.
* OTC decongestant nasal sprays should be discouraged for use more than 5 days
* Supportive therapy: Humidification, analgesics, antihistaminics
a) Amoxicillin (500mg TID) OR
b) TMP/SMX ( one DS for 10 days).
c) Alternative antibiotics: High dose amoxi/clavunate, Flouroquinolones, macrolides

Antibiotics
Acute Pharyngitis
* Fewer than 25% of patients with sore throat have true pharyngitis.
* Primarily seen in 5-18 years old. Common in adult women.

Etiology
A) Viral: Most common.
Rhinovirus (most common).
Symptoms usually last for 3-5 days.

B) Bacterial: Group A beta hemolytic streptococcus (GABHS).
Early detection can prevent complications like acute rheumatic fever and post streptococcal GN.

Signs and Symptoms
* Absence of Cough
* Fever
* Sore throat
* Malaise
* Rhinorrhoea
* Classic triad of GABHS: High fever, tonsillar exhudates and ant. cervical lymphadenopathy.

NO COUGH
Diagnosis
* Physical Exam: Tonsillar exhudates, anterior cervical LAD
* Rapid strep: Throat swab. Sensitivity of 80% and specificity of 95%.

Throat Cultures: Not required usually. Needed only when suspicion is high and rapid strep is negative.

Exhudates
Management
A) Symptomatic: Saline gargles,

analgesics, cool-mist humidification and throat lozenges.

B) Antibiotics:
a) Benzathine Pn-G 1.2 million units IM x 1OR Pn V orally for 10 days
b) For Pn allergic pts:Erythromycin 500mg QID x 10 days OR Azithro 500 mg Qdaily x 3 days.

Acute Bronchitis
Inflammation of the bronchial respiratory mucosa leading to productive cough.
Acute Bronchitis
* Etiology: A)Viral
B) Bacterial (Bordetella pertussis, Mycoplasma pneumoniae, and Chlamydia pneumoniae)
* Diagnosis: Clinical
* S/S: Productive cough, rarely fever or tachypnea.

Treatment
* Symptomatic
* If cough persists for more than 10 days:

Azithro x 5 days OR
Clarithro x 7 days
Non specific URI’s

* Common Cold
* Etiology: Rhinovirus
Adenovirus
RSV
Parainfluenza
Enteroviruses
Diagnosis: Clinical
Treatment: Adequate fluid intake, rest, humidified air, and over-the-counter analgesics and antipyretics.

Influenza
* Etiology: Influenza A & B
* Symptoms: Fever, myalgias, headache, rhinitis, malaise, nonproductive cough, sore throat
* Diagnosis: Influenza A &B antigen testing
* Treatment: Supportive care, oseltamivir, amantidine

Upper Respiratory Tract Infections.ppt

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Hepatitis A & B

Hepatitis A

The virus that does not cause chronic liver disease

Hepatitis A
* “Infectious Hepatitis”
* First characterized in 1973
* Detected in human feces
* Hepatovirus genus
* A reportable infectious disease
* U.S. rate of infection 4/100,000
* Highest among children

Risk Factors
* Sexual or household contact
* International travel
* Men who have sex w/ men (MSM)
* Intravenous drug abuse (IVDA)
* Daycare

Transmission
* Unwitting contact w/ infected person
* Most cases unknown
* Primary route is fecal oral either by person to person contact or ingestion of contaminated food or water

Pathogenesis
* After ingestion, the HAV survives gastric acid, moves to the small intestine and reaches the liver via the portal vein
* Replicates in hepatocyte cytoplasm
o Not a cytopathic virus
o Immune mediated cell damage more likely
* Once mature the HAV travels through sinusoids and enters bile canaliculi, released into the small intestine and systemic circulation, excreted in feces

Clinical Features
* Incubation is usually 2 to 4 weeks, rarely 6 weeks
* Complete recovery within 2 months for > 50%
* Within 6 months for almost all others
* Low mortality in healthy people
o High mortality when older than age 60
o High in presence of chronic liver disease
* High morbidity
o Around 20% need hospitalization
o Lost work days
o Most become jaundiced
* Asymptomatic < 2 year old * Symptomatic – 5 and older ill about 8 weeks * Cholestatic – jaundice lasts > 10 weeks
* Relapsing w/ 2 or more bouts acute HAV over a 6 to 10 week period
* Acute liver failure – rare in young. When it occurs, is rapid i.e., within 4 weeks

Signs and Symptoms
* Prodrome lasts 1-2 weeks: fatigue, asthenia, anorexia, nausea, vomiting, and abdominal pain
* Less common: fever, cephalgia, arthralgia, myalgia, and diarrhea
* Dark urine is followed by jaundice and hepatomegaly
* Less common: splenomegaly, cervical lymphadenopathy

Diagnosis
* During acute infection, anti HAV IgM appears first
* HAV IgG antibody appears early in the course of infection and remains detectable for life, providing lifelong immunity

Prevention Immunization
* All children 12 – 24 months
* Travelers, occupational exposure risk
* All patients w/ hepatitis B or C or those awaiting liver transplantation
* HIV positive patients
* MSM
* IVD users
* People w/ clotting factor deficiencies
* Lab workers handling live hepatitis A vaccine
* Need for post exposure prophylaxis uncommon. Administration of the vaccine is effective. If needed, administer immune serum globulin within 2 weeks 0.02 ml/Kg IM

Hepatitis A Vaccine
* The vaccine is inactivated HAV
* Schedule for 2 – 18 years depends upon the manufacturer:
o Havirx: 720 EL U/.5mL @ 0, 6-12 mo
o Vaqta: 25 U.5mL @ 0, 6-18 mo
* For those over age 18:
o Havirx: 1440 EL U/1mL @ 0, 6-12 mo
o Vaqta: 50 U/1mL @ 0, 6-18 mo
* Adverse effects: rarely anaphylaxis, injection site induration, erythema, edema, fatigue, mild fever, malaise, anorexia, nausea
* Twinrix:
o 720 El U/1mL 0, 1, 6 mo plus
o 20 mcg HBV

Questions?
Hepatitis B
The Virus
* The hepatitis B virus is among the smallest genomes of all known animal viruses
* A DNA virus that infects only humans
* Belongs to the family Hepadnaviridae
* Knowledge of the viral proteins that are perceived by the immune system as “antigens” aids understanding of the various tests used to diagnose acute, chronic, and resolved infection and verify response to immunization

HBV Antigens
* Outer envelope contains a surface protein called hepatitis B surface antigen
* HBsAg is a marker of viral replication
* Inner core contains the genome, the DNA polymerase w/ reverse transcriptase activity, hepatitis B core antigen (HBcAg) particles. This antigen is not detectable in serum
* A truncated form of the major core polypeptide known as hepatitis e antigen (HBeAg) is the third antigen generated by virus activity. Marker of high infectivity

Hepatitis B Antibodies
* Hepatitis B surface antibody is the antibody to surface antigen. HBsAb is protective and indicates either resolved infection or immunization
* HBcAb is the antibody to core antigen. This is not a protective antibody. Only those who have been exposed to the virus will have this antibody
* HBcAb is measured in serum as:
o Anti HBc IgM (usually indicates new infection)
o Anti HBc IgG (appears later)
* HBeAb is the antibody to e antigen. Loss of e antigen w/ gain of e antibody is called seroconversion. Not a protective antibody

Epidemiology
* Prevalence of HBV varies markedly around the world, w/ > 75% of cases in Asia and the Western Pacific
* Vaccine available > 20 years, but perinatal and early life exposure continue to be a major source of infection in endemic areas
* Most acute HBV cases in the U.S. are seen among young adults, males > females, who use injection drugs and in those who engage in high risk sexual behaviors
* In the U.S., hundreds of people die each year of fulminant HBV
* World wide, chronic HBV and its complications including hepatocellular carcinoma account for > 1 million deaths each year

Risk Factors

* Percutaneous and mucous membrane exposure. The virus is 100 x more infectious than HIV, 10 x more infectious than HCV and is present in all body fluids. Present on horizontal surfaces, eating utensils, personal hygiene items, etc.
* Babies born to infected mother
* Household contact
* Hemodialysis
* Receipt of blood products prior to the early 1970s
* Receipt of previously infected donor liver

Markers of Exposure
* Surface antigen appears as early as 1-2 weeks following exposure, as late as 11-12 weeks
* HBV DNA measurable soon after
* HBeAg appears shortly after HBsAg
* Hepatitis occurs 1 – 7 weeks after appearance of HBsAg

Pathophysiology
* Governed by interaction between the virus and host immune response
* Following inoculation by the HBV, cytokine release, cell injury and viral clearance follow
* HBsAg disappears by six months and is accompanied by sero conversion to protective HBsAb
* Persistent virus replication after six months ->chronic hepatitis and is the result of a compromised (newborn/HIV) or relatively tolerant immune system status

Four Stages of Infection
* Age at time of infection predicts chronicity in most cases. Infants and young children usually become chronically infected. When acquired in adults, the virus is cleared by the healthy immune system in about 95% of cases, leading to natural immunity
* Immune tolerant phase, there is active viral replication. ALT and AST are normal. Immune system does not recognize HBV as “foreign”
* In the immune clearance phase, enzymes rise reflecting immune mediated lysis of infected hepatocytes. This phase can last for years. Seroconversion of HBeAg to HBeAb occurs

Stages of Infection
* Low or non-replicative phase. Also known as inactive carrier (or inappropriately “healthy carrier”). Characterized by resolution of necroinflammation, normalization of enzymes and low levels of HBV DNA. This stage may last for life
* Reactivation. Spontaneous or immunosuppression mediated (cancer chemotherapy or high dose corticosteroid therapy)

Signs and Symptoms
* Incubation period: a few weeks to 6 months
* About 30% develop jaundice
* 10% to 20% of patients develop serum sickness, i.e., fever, arthralgias, rash
* Fulminant hepatitis B occurs in < 1% of cases. 80% mortality without liver transplantation * Enzyme elevations of 1,000-2,000 typical Signs and Symptoms * Fatigue, RUQ discomfort may be the only symptoms * Those in the immune tolerant phase are usually asymptomatic. The phase lasts until late puberty into adulthood Signs of Decompensation * See section on Cirrhosis and Portal Hypertension * Refer to a liver transplantation center * Patient education for people with chronic liver disease should be reinforced * Refer to “Ten Tips for People w/ Chronic Liver Disease” Prevention * Two forms of vaccine now available. * Twinrix – contains both hepatitis A and B vaccines available in an accelerated schedule or standard series * Individual hepatitis B vaccine * Standard schedule is given: o Time 0 o 1 mo o 6 mo Prevention * Educate to avoid IVDU, high risk sexual activity * Prevent peri natal transmission. Serology of pregnant women for HBsAg is standard of practice in U.S. * If pregnant female has high viremia, refer to hepatologist for treatment during the 3rd trimester to reduce risk of transmission to neonate * Babies of HBsAg mothers receive hepatitis B immune globulin with 12 hours of birth and begin the vaccine series immediately Treatment * Six approved medications as of July 2008 o Interferon alpha o Pegylated interferon o Lamivudine o Adefovir Dipivoxil o Entecavir o Telbivudine o Tenofovir approved * Refer to hepatologist The Cholestatic Liver Diseases Adults Cholestatic Liver Disease Etiologies * Immune Mediated: PBC, PSC, autoimmune cholangitis, liver allograft rejection, graft-versus-host disease * Infectious: acute viral hepatitis * Genetic and Developmental: cystic fibrosis, Alagille’s syndrome (syndrome w/ paucity of intrahepatic bile ducts), fibro polycystic liver disease * Neoplastic: Cholangiocarcinoma * Drug-Induced Ductopenia: amoxicillin, amitriptyline, cyproheptadine, erythromycin, tetracycline, thiabendazole * Ischemic * Idiopathic Pathogenesis of Cholestatic Disorders * Immune response (inflammation, auto-antibody) or hepatotoxic injury to bile ducts * Bile duct injury by bile acids - >
* Retention of bile acids in hepatocytes - >
* Liver cell damage, apoptosis, necrosis, fibrosis, cirrhosis - > liver failure

Complications of Chronic Cholestasis
* Pruritis believed to be 2/2 increased opioid receptor tone, or centrally mediated
* Fatigue
* Bone disease: osteopenia, osteoporosis
* Fat soluble vitamin deficiency
* Malabsorption (Sprue, bile salt deficiency, pancreatic insufficiency)

Pruritis in Cholestasis

* Therapy:
o Urso in AICP, PBC (15-30mg/Kg/day)
o Opiate antagonist naltrexone (50mg/day)
o 5-HT3 antagonist odansetron
o SSRI sertaline
o Bile acid sequesterant cholestyramine 4gm t.i.d. to q.i.d.
o Antihistamines rarely effective
o Rifampin 150mg to 300mg b.i.d.

Fatigue in Cholestasis
* High prevalence in Primary Biliary Cirrhosis unrelated to disease severity or duration
* Pathogenesis
o ?decreased hypothalamic cortico-tropin-releasing hormone
o ?CNS accumulation of manganese
* Prognosis worse
* No effective treatment

Bone Disease in Cholestasis
* Clinical manifestations: low bone density, fractures of axial and/or appendicular skeleton
* Pathogenesis: hyperbilirubinemia impairs osteoblast proliferative activity
* Therapy: bisphosphonates, calcium, vitamin D, weight bearing exercise, estrogens appear to be safe

1. Primary Biliary Cirrhosis
A chronic and progressive disease of unknown etiology affecting primarily middle-aged women

Primary Biliary Cirrhosis
* Affects all races
* 9:1 ratio female > male, age 20 – 65
* Characterized by small intrahepatic bile duct destruction and cholestasis
* In the presence of cirrhosis, male > likely than female to develop hepatocellular carcinoma

PBC
Laboratory Findings
* Alk Phos 2x to 20x ULN in > 90% of patients
* AST-ALT 1x to 5x ULN > 90%
* Bilirubin – variable. When elevated, may indicate advanced cirrhosis or 2nd condition
* Hypercholesterolemia in 80% of patients

Hypercholesterolemia Unique in PBC
* Hypercholesterolemia
* IgM 1x to 5x ULN > 90%
* Anti mitochondrial antibody > 1:20 titer >90%
* Anti nuclear and/or smooth muscle antibody > 1:80 may be seen in “overlap syndrome”
* Liver biopsy helpful to grade and stage disease, determine if cirrhosis present

PBC Treatment
* Slowly progressive, even if asymptomatic
* Ursodeoxycholic acid only effective therapy. May improve natural history
* Transplant curative
* Manage disease specific complications

Effects of Ursodeoxycholate
* Urso is a hydrophilic bile acid having multiple anti-inflammatory and immunomodulatory actions
* Urso administration in the setting of pro-apoptotic stimuli (bile salts, ethanol, TGF-beta, FAS ligand) inhibits in vitro apoptosis (programmed cell death)
* Reduces mitochondrial membrane permeability

Monitor for and Treat PBC Associated Disorders
* Keratoconjunctivitis Sicca
* Scleroderma, CREST syndrome
* Gallstones
* Arthropathies:
o Rheumatoid, psoriatic arthritis, Raynaud’s phenomenon, Hypertrophic osteodystrophy, Avascular necrosis, Chondrocalcinosis
* Thyroid disease, renal tubular acidosis

PBC Associated Disorders
* Malabsorption
* Celiac Sprue
o 6% of PBC patients have Celiac Sprue
o 3% of Sprue patients have PBC
* Bile salt deficiency
* Pancreatic insufficiency

Manage PBC Complications
* Standard liver disease recommendations
* PBC specific symptom management
* Refer for liver transplantation
* Primary Sclerosing Cholangitis
Rare
* One of the most important cholestatic liver diseases in the western world
* Chronic, cholestatic liver disease characterized by
o Inflammation
o Obstruction
o Fibrosis of both intrahepatic and extrahepatic bile ducts

Primary Sclerosing Cholangitis
* Many patients will progress to cirrhosis
* Highly variable in and between individuals
* Usually fatal important complication is cholangiocarcinoma
* Etiology largely unknown, though evidence points to immune system involvement

PSC
* No specific treatment
* Treatment aimed at management of disease associated conditions
* Prevalence unknown
* Almost half are asymptomatic at diagnosis
* No specific diagnostic marker for PSC

PSC Clinical Features
* Labs:
o Two- fold increase in alk phos, most have increased AST and ALT
o Albumin and protime normal in early disease
o Bilirubin initially normal, but gradually increases and fluctuates widely w/ extrahepatic biliary strictures, infection, obstructing stone sludge or stone
* Imaging
* Magnetic resonance cholangio-pancreatography demonstrates intrahepatic duct changes
* Histology
* Liver biopsy for staging the disease
* Liver biopsy to rule out other potentially treatable causes of cholestasis

PSC Patient Presentation
* Large bile duct PSC may have asymptomatic elevation of LFTs. Can be cirrhotic w/ no symptoms
* Symptomatic patients will have cholestasis-type symptoms plus:
o Abdominal pain
o Weight loss
o Hepatomegaly
o Acute cholangitis

PSC Associated Diseases
* Inflammatory bowel disease, most often ulcerative colitis
* These patients have increased risk for colorectal carcinoma
* 25% have another autoimmune disease

PSC Complications
* Related to cholestasis: pruritis, fatigue, fat soluble vitamin deficiency, osteoporosis
* Related to cirrhosis: liver failure, peristomal varices
* Extra-hepatic disease: IBD, pancreatitis, sprue, diabetes, thyroid disease
* PSC specific

PSC Disease Specific Complications
* Fever
* Abdominal pain
* Dominant stricture
* Gall stones
* Cholangiocarcinoma

PSC Prognosis
* Factors of Importance:
o Older age
o Increasing bilirubin
o Histological advanced stage
o Child-Pugh-Turcotte Class C

PSC Treatment Goal Improve Quality of Life
* Medical support
* Endoscopic treatments
* Surgical interventions
* Liver transplantation – PSC recurrence is more frequent than PSC

Case Study
Reference

Hepatitis A & B .ppt

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Magnetic Resonance CholangioPancreatography

Magnetic Resonance CholangioPancreatography
By:Falguny Bhavan MS4
Oregon Health & Sciences University
Radiology Clerkship


Objectives
* Introduction
* Technique
* Advantages
* Limitations
* Clinical applications

Introduction
Anatomy of the Hepato-Biliary and Pancreatic system

Technique
* Basic principle: body fluids (bile and pancreatic secretions) have high signal intensity on heavily T2-weighted MR sequences therefore, appear white
o Background tissues generate little signal appear dark
* Stationary or slow-flowing fluid within the bile and pancreatic ducts appears bright relative to low signal intensity produced by adjacent solid tissues
* New MR advancements allow faster imaging in which imaging is performed during single breath-holding session to reduce motion artifact due to respiration
* New variants such as rapid acquisition with relaxation enhancement (RARE) and half-Fourier acquisition single-shot turbo spin-echo (HASTE) can be performed in a breath-hold period with a scan time of <20 seconds provide superior images Advantages * Does not require intravenous or oral contrast material to be administered into the ductal system * Avoids complications of ERCP such as pancreatitis (3-5%), sepsis, perforation, hemorrhage, sedation * Can be completed in 10 minutes, easily performed as outpatient examination * Passive procedure; displays the ducts in the resting state and more accurately displays native caliber of the duct than ERCP. o In ERCP, segments may be overdistended because of attempt to visualize the duct upstream from a stricture, or segments may be underdistended because of the operator's fear of inducing cholangitis or pancreatitis. Limitations * Purely diagnostic, does not provide access for therapeutic intervention (e.g. stone extraction, stent insertion, or biopsy) * Image artifact due to other structures in abdomen with high fluid content * Lack of patient compliance; claustrophobia, inability to breath-hold * Dropout of signal can be caused by metallic clips, crossing defects induced by the right hepatic artery, or from severely narrowed ducts, such as occurs with primary sclerosing cholangitis * Lower resolution than direct cholangiography o Can miss small stones (<4 mm), small ampullary lesions, primary sclerosing cholangitis, and strictures of the ducts Clinical applications: Diseases Diagnosed by MRCP Biliary Disease * Screening examination in patients with low or intermediate probability of choledocholithiasis * Cholangiocarcinoma * Anatomic variants (low or medial duct insertion, aberrant right hepatic duct) * Failed or incomplete ERCP * Post-operative anatomy or screening for biliary complications * Primary sclerosing cholangitis * Cystic disease of bile duct (choledochal cyst, choledochocele, Caroli’s disease) Pancreatic Disease * Anatomic variants (pancreas divisum) * Chronic pancreatitis * Pancreatic cancer Clinical Applications: General guidelines for selection of MRCP or ERCP Obstruction of the Common Bile Duct * MRCP can visualize the normal or dilated common bile duct in 96 to 100 percent of patients. * Strictures typically appear as focal areas of ductal narrowing or signal void with proximal dilatation. * Cause of biliary strictures may be more difficult to determine on the basis of MRCP alone. o lacks specificity o differentiation between benign and malignant causes is based on a combination of clinical, radiographic, and pathological data * Obstruction 2° to calculi, pancreatic adenocarcinoma, or pancreatitis is usually obvious with MRCP, and with aid of conventional MRI or CT Obstruction Combined Biliary-Duct Obstruction and Pancreatic-Duct Obstruction Due to a Small Mass in the Pancreatic Head. The biliary-duct obstruction is indicated by the curved arrow, and the pancreatic-duct obstruction by the straight arrow. The mass was identified on axial, contrast-enhanced, T1-weighted images (not shown) obtained by routine MRI during the same examination. Arrowheads indicate the pancreatic duct. * ERCP is more beneficial in pts with dilatation of the common bile duct who have obstruction at the ampulla, since it permits direct visualization of the ampulla, biopsy of lesions, manometry, or endoscopic sonography. * MRCP Study of 79 cases of biliary obstruction found 14 due to malignant cause; 6 cases due to ampullary carcinoma. o 2 of 6 cases were misdiagnosed as benign obstructions, and 2 cases of benign obstruction were thought to be ampullary cancers. (This study used an early form of the technique, and results may be more accurate with the currently available technology.) * MRCP performed after pharmacologic stimulation with secretin has been shown to be helpful in evaluating ampullary obstruction Secretin-enhanced MRCP * Visualization of the pancreatic duct can be improved with imaging after administration of IV secretin * Secretin frequently used when pancreatic duct is not apparent on MRCP * Reduces the incidence of false positive findings of strictures Secretin-enhanced MRCP Dynamic MRCP with Intravenous Injection of Secretin in Patient with Abdominal Pain after a Whipple Procedure. (ERCP was not attempted because the patient had a pancreaticoenteric anastomosis.) In Panel A, the pancreatic duct (arrowheads) is incompletely visualized on MRCP before the administration of secretin. In Panel B, an MRCP obtained 15 minutes after the administration of secretin shows prominent and prolonged dilatation of the pancreatic duct upstream of a stricture (arrow) at the pancreaticoenteric anastomosis. Common duct stones * Displayed by MRCP as a signal void within bright signal arising from bile * MRCP is a useful means of determining presence or absence of CBD stones, as well as number, size, and location * MRCP is as accurate as ERCP for detecting choledocholithiasis o Sensitivity = 95-100% o Specificity = 85-100% * Increased sensitivity in pts with suspected gallstone pancreatitis, and pts with non-specific abdominal pain and normal LFTs * Stones larger than 4 mm are readily seen but difficult to differentiate from filling defects such as blood clots, tumor, sludge, or parasites o Other mimickers include flow artifacts, biliary air, and a pseudostone at the ampulla * In the presence of a dilated CBD, MRCP has a 90 to 95 percent concordance with ERCP in diagnosing CBD stones over 4 mm in diameter * ERCP is preferred in pts with cholangitis because it allows therapeutic drainage Cholangiocarcinoma * Role of MRCP in the diagnosis and management of bile duct malignancy is not yet defined * Useful noninvasive adjunct * Capability to evaluate the bile ducts both above and below a stricture while also identifying any intrahepatic mass lesions * Study of 126 patients with suspected bile duct obstruction showed that MRCP alone has limited specificity in the diagnosis of malignant strictures o Malignant obstruction dx by MRCP in 12 out of 14 pts o Positive predictive value = 86% o Negative predictive value = 98% Pancreatitis * Acute pancreatitis o MRCP is useful for evaluating bile ducts and cystic duct remnants for stones, for evaluating the pancreatic ducts, and for documenting the presence of cysts in or around the pancreas. o ERCP is often preferred in patients with gallstone pancreatitis since endoscopic papillotomy can be performed in pts with obstructive jaundice or biliary sepsis. * Chronic pancreatitis o MRCP is useful in demonstrating complications such as, ductal dilatation, strictures, intraductal calculi, fistulas, and pseudocysts o Defines ductal anatomy and extent of ductal disease prior to surgical drainage * MRCP is as accurate as ERCP for distinguishing pancreatic cancer from chronic pancreatitis. o In study of 124 patients who were suspected of having pancreatic cancer, pts underwent a number of diagnostic studies, including ERCP and MRCP. The correct diagnosis was confirmed histologically and clinically. 37 patients (30 percent) dx with pancreatic cancer; others had chronic pancreatitis (46 percent) or other causes. o MRCP sensitivity (84%) and specificity (97%) for diagnosis of pancreatic cancer o ERCP sensitivity (70%) and specificity (94%) * Secretin-enhanced MRCP is being increasingly studied for evaluation of pancreatic exocrine function and in the early diagnosis of chronic pancreatitis Variant ductal anatomy * MRCP is also useful in demonstrating variant anatomy and congenital anomalies of the biliary tract and pancreatic duct o Pancreas divisum o Choledochal cyst o Annular pancreas o Abnormal pancreaticobiliary junctions o Aberrant bile ducts * And in evaluation of pts prior to laparoscopic cholecystectomy Normal Extrahepatic Bile Duct and Incidental Pancreas Divisum. Magnetic resonance cholangio-pancreatography is an accurate method of diagnosing pancreas divisum because it shows the dominant dorsal pancreatic duct (arrowheads) continuously from the tail to the head of the pancreas, crossing the common bile duct (curved arrows) and draining at the minor papilla (straight arrow) superiorly and separately from the common bile duct. GB denotes gallbladder. Failed or incomplete ERCP * ERCP is technically challenging o Associated with 10-20% failed cannulation rate o Anatomic variants can contribute to failed ERCP attempts * MRCP is useful in demonstrating variant anatomy o MRCP may have advantages compared to ERCP in specific settings such as pts who have gastric outlet or duodenal stenosis or who have had surgical rearrangement (eg, Billroth II) or ductal disruption, resulting in ducts that can’t be assessed by ERCP * MRCP also allows evaluation of ducts in pts with contraindications for ERCP: o Cervical spine fractures, head and neck tumors, sleep apnea, other diseases/ injuries that preclude placement of endoscope or positioning Post-surgical anatomy Normal Results of Magnetic Resonance Cholangiopancreatograpy in a Patient after Cholecystectomy. Imaging was performed in two seconds with the thick, single-slice technique. The normal common bile duct (arrow) and pancreatic duct (arrowheads) are clearly visible. Du denotes duodenal bulb. References Magnetic Resonance CholangioPancreatography.ppt

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