-
Right upper quadrant (RUQ) pain is a common complaintthat
typically stimulates a workup of the hepatobiliarysystem. In
particular, evaluation of the gallbladder (GB) isimportant because
cholelithiasis and its complications area frequent cause of RUQ
pain. For this reason, tests used inthis condition must be capable
of providing accurate infor-mation about the GB. This chapter
focuses on the imagingevaluation of the patient with RUQ pain and
illustrateswhy the use of ultrasound is so important.
Differential Diagnosis
Gallstone disease is one of the most common causes ofRUQ pain.
Gallstones are present in ∼10% of the popula-tion.1 In North
America, 75% of gallstones are cholesterolstones; the rest are
pigment stones.2 In women, factors thatpredispose to gallstones are
increased weight, increasedage, and increased parity. In men,
increased age also pre-disposes to gallstones.1
Although gallstones are one of the most commoncauses of RUQ
pain, the majority of patients with gall-stones are asymptomatic.2
Imaging studies performed forother reasons often discover patients
with asymptomatic(silent) gallstones. Silent gallstones tend to
become symp-tomatic at a rate of ∼2% per year.3,4 The overall risk
after 20years is 18%.3 Patients with gallstones are unlikely to
de-velop symptoms after 10 to15 years of being asympto-matic. Those
patients who ultimately do develop symp-toms almost always have
episodes of biliary colic first. It isvery unusual for a patient to
develop acute cholecystitis asthe initial symptom of gallstone
disease without previousincidents of colic. Based on these
statistics and the knownrisk of cholecystectomy, it has been shown
that perform-ing prophylactic cholecystectomy in asymptomatic
pa-tients actually decreases their overall life expectancy
andincreases the cost of treatment.5 For these reasons,
asymp-tomatic gallstones are generally not treated surgically.
Approximately one third of all patients with gallstoneswill
develop symptoms. Patients with symptomatic gall-stone disease
generally first seek medical attention due tobouts of biliary
colic. As already mentioned, patients thatfirst present with acute
cholecystitis will generally de-scribe previous episodes consistent
with biliary colic. Dys-peptic symptoms (pyrosis, flatulence, vague
abdominaldiscomfort, and fatty food intolerance) may occur in
pa-
tients with gallstones but it is hard to prove a
cause-and-effect relationship because these symptoms are also
verycommon in patients without gallstones.2
The symptom complex of biliary colic is producedwhen a stone
obstructs the cystic duct or GB neck. Classi-cally, these patients
experience acute RUQ or epigastricpain that increases in intensity
over several seconds orminutes and then persists for several
(usually 4 to 6) hours.The pain may begin in the RUQ and radiate to
the epigas-trium or vice versa. It may occasionally be most severe
inthe left upper quadrant, precordium, or even the lower
ab-domen.2,6 Periodic exacerbations may occur during a
givenepisode, but, in general, the pain is fairly steady (colic is
amisnomer). In most cases, there is no obvious cause of bil-iary
colic. In some patients, the pain is provoked by a meal.Tenderness
to palpation is unusual.
Biliary colic may be relieved if the obstructing
stonespontaneously disimpacts from the cystic duct or GB neck.It
may also be relieved if the stone passes through the cys-tic duct
and into the bile duct. If the stone subsequentlyobstructs the
common bile duct, a second episode of bil-iary colic may occur. The
interval between attacks of bil-iary colic is very unpredictable
and can vary from weeks tomonths to years.
Acute cholecystitis develops if there is persistent cysticduct
or GB neck obstruction. This diagnosis should be con-sidered when
the patient’s symptoms persist beyond 6hours. Acute cholecystitis
is manifest as persistent RUQpain that may radiate to the right
shoulder, right scapula,or interscapular area. Nausea, vomiting,
chills, fever, andRUQ tenderness and guarding are common.
Leukocytosisand elevations of alkaline phosphatase,
aminotransferase(transaminase), and amylase may occur. Mild
hyperbiliru-binemia is seen in as many as 20% of cases.7 Bilirubin
levelsgreater than 4 mg/100 mL may occur if there is commonbile
duct obstruction.
In addition to GB disease, many other disease processescan
potentially produce RUQ pain.8 These are listed in Table1–1. In
particular, liver diseases should be strongly consid-ered,
including diffuse hepatic parenchymal diseases suchas hepatitis
(viral, alcoholic, drug induced, or toxin in-duced) or passive
hepatic congestion, or focal hepatic dis-eases. Focal liver tumors
can produce pain due to rapidgrowth, bleeding, or infarction.
Hepatic abscesses, perihep-atitis (Fitz-Hugh-Curtis syndrome),
hematomas, and hem-orrhagic cysts are also capable of producing RUQ
pain.
Right Upper Quadrant PainWilliam Middleton1
AQ1
-
ally presents primarily as RUQ pain. Peptic ulcer
disease,colitis, ileitis, intestinal obstruction, irritable bowel
syn-drome, and intestinal tumors are additional
considera-tions.
The right kidney is another source of RUQ pain. Renalcolic may
present with atypical symptoms and be con-fused with GB disease.
Pyelonephritis, renal abscess,hematoma, hemorrhagic cysts, tumors,
and ischemia areother renal diseases that can cause RUQ pain.
Miscellaneous other processes to be considered in pa-tients with
RUQ pain are right-lower-lobe pneumonia andpulmonary infarction,
myocardial ischemia, local chestand abdominal wall lesions, local
musculoskeletal lesions,right adrenal lesions, and herpes
zoster.
The relative prevalence of the different causes of RUQpain
varies from institute to institute. Table 1–2 catego-rizes these
causes by their approximate prevalence.
Diagnostic Evaluation
Nonimaging Tests
In many patients with RUQ pain, a careful history and phys-ical
examination will help guide the workup in the appro-priate
direction. However, the signs and symptoms of themany conditions
potentially capable of causing RUQ painoverlap greatly. For this
reason, there is a multitude of use-ful diagnostic tests. The most
common tests are (1) liverfunction tests (LFTs), (2) amylase
levels, (3) urinalysis, (4)white blood cell counts, and (5)
electrocardiograms (ECGs).
The bile ducts can also be responsible for RUQ pain. Bil-iary
colic from an obstructing common bile duct stone isprobably the
most frequent cause of bile duct–related RUQpain. Cholangitis,
choledochal cysts, and tumors are otherpossibilities.
Pancreatitis may also cause confusion because it canboth
simulate and coexist with GB disease. A transientepisode of biliary
colic may be followed by an episode ofpancreatitis as the stone
passes through the common ductand obstructs the pancreatic
duct.
Gastrointestinal abnormalities should also be consid-ered in the
differential diagnosis. Appendicitis occasion-
I The Abdomen4
Table 1–1 Differential Diagnosis of Right Upper Quadrant
Pain
1. Biliary colic
2. Acute cholecystitis
3. Acute pancreatitis
4. Acute appendicitis
5. Disorders of the livera. Acute hepatitis
i. Alcoholicii. Viral
iii. Drug-relatediv. Toxins
b. Hepatic abscessc. Hepatic tumors
i. Metastasesii. Hepatocellular cancer
iii. Hemangiomaiv. Focal nodular hyperplasiav. Hepatic
adenoma
d. Hemorrhagic cyste. Hepatic congestion
i. Budd-Chiari syndromeii. Acute hepatic congestion
6. Disorders of the bile ductsa. Bile duct obstructionb.
Cholangitis
7. Disorders of the intestinesa. Peripyloric ulcers with or
without perforationb. Small bowel obstructionc. Irritable boweld.
Colitise. Ileitisf. Intestinal tumors
8. Costochondritis of the lower right anterior chest
9. Perihepatitis due to gonococcal or chlamydial infection
(Fitz-Hugh-Curtis syndrome)
10. Pleuroabdominal pain due to pneumonia or pulmonary
infarction
11. Disorders of the right kidneya. Acute pyelonephritisb.
Ureteral calculusc. Renal or perirenal abscessd. Renal infarctione.
Renal tumor
12. Unknown causes
13. Herpes zoster
Table 1–2 Causes of Right Upper Quadrant Pain
Common Uncommon Rare
Biliary colic Drug-related and Budd-Chiari toxic hepatitis
syndrome
Cholecystitis Hepatic hemangioma
Acute Hepatic abscess Hepatic adenomapancreatitis
Acute Hepatocellular Focal nodular appendicitis carcinoma
hyperplasia
Alcoholic Ascending hepatitis cholangitis
Viral hepatitis Acute pyelonephritis Pneumonia/pleuritis
Hepatic Renal tumor Renal abscessmetastases
Irritable bowel Peptic ulcer disease Perinephric abscess
Costochondritis Renal infraction
Unknown cases Perihepatitis(Fitz-Hugh-Curtissyndrome)
AQ8
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LFTs are among the most useful initial laboratory testsbecause
certain abnormalities strongly suggest hepatobil-iary disease. In
addition, the pattern of abnormality onLFTs can point toward liver
parenchymal processes or bil-iary processes. (Please see the
chapter on evaluation of ab-normal LFTs .) Renal, pancreatic, and
cardiac abnormalitiescan be identified in many cases by obtaining a
urinalysis, aserum amylase level, and an ECG.
Imaging Tests other than Ultrasound
The initial imaging tests in patients with RUQ pain shouldbe
radiographs of the chest and abdomen. These are rapidand
inexpensive ways of evaluating the patient for pul-monary and
intestinal sources of pain. In addition, abdom-inal radiographs can
detect calcifications in the kidney,ureter, appendix, and pancreas.
Gallstones that are suffi-ciently calcified to be radiopaque (10 to
15% of cases) canalso be detected. Rarely, gallstones will contain
enough gasto be visible on radiographs. Therefore, although
abdomi-nal radiographs may reveal gallstones, a negative studydoes
not exclude the diagnosis.
If the patient presents with suspected biliary colic andthe
preliminary tests fail to suggest an alternative sourceof pain,
then the GB should be evaluated to determine thepresence or absence
of gallstones. In addition to abdomi-nal radiographs, there are
several imaging tests that are ca-pable of detecting gallstones.
The sensitivity of these vari-ous tests is indicated in Table
1–3.
Computed tomography (CT) is much better at detectingsmall
degrees of calcification than plain radiography and istherefore
more sensitive at detecting gallstones. CT canalso detect some
cholesterol stones that are less densethan surrounding bile as well
as stones that contain gas. Inaddition, unlike abdominal
radiography, CT can determinethe anatomical location of a
calcification and confirm thatit is in the GB. Unfortunately, at
least 20% of gallstoneshave the same attenuation as bile and are
not detectablewith CT.9 For this reason, CT is useful when positive
but notuseful when negative.
Oral cholecystography (OCG) was the preferred meansof diagnosing
gallstones for many years. When the GB iswell opacified, OCG is
similar to sonography in its ability todetect and exclude
gallstones. Sensitivity decreases some-what if opacification is
faint on an OCG. In ∼25% of OCGs,the GB is not opacified. If
nonvisualization of the GB is con-
sidered a positive result, then the sensitivity of OCG for
de-tecting stones is as high as 90 to 95%.10,11 Unfortunately,there
are many nonbiliary causes of nonvisualization.These include
failure to take the contrast, vomiting, diar-rhea, fasting, hiatal
hernia, proximal intestinal obstruction,proximal intestinal
diverticulum, malabsorption, and liverdisease.11 Therefore,
nonvisualization of the GB is less spe-cific for gallstones than
the typical finding of a mobile fill-ing defect in a well-opacified
GB. If a nonvisualized GB isconsidered an inconclusive result, then
the sensitivity ofOCG is 65%.10 Currently, OCG is mostly of
historic signifi-cance and is almost never performed.
Ultrasound Imaging
Many investigations performed in the late 1970s and early1980s
analyzed the effectiveness of sonography in detect-ing gallstones.
Despite using static scanners and first-gen-eration real-time
equipment, these studies almost allshowed that sonography was
highly accurate (> 90%) indetecting gallstones. Since then,
sonography has essen-tially replaced the OCG for the detection of
gallstones. Datafrom slightly more recent studies continue to
support thisapproach. One blinded prospective comparison of
thesetechniques showed a sonographic sensitivity of 93% and anOCG
sensitivity of 65%.10 In this same study, if a nonvisual-ized GB on
OCG was considered positive for gallstones,then the sensitivity of
OCG increased to 87%. Anotherstudy on patients who were morbidly
obese showed asonographic sensitivity of 91% and specificity of
100%. Inthis patient population, which is not ideal for
sonography,the negative predictive value was still very high at
97%.12
The typical sonographic appearance of a gallstone is amobile,
shadowing, echogenic structure in the lumen ofthe GB (Fig. 1–1).
The positive predictive value of this triadof findings is 100%.
When shadowing is not detected, thedifferential includes gallstones
and tumefactive sludge.Small, mobile, nonshadowing intraluminal
structures aregenerally gallstones (Fig. 1–2). On the other hand,
tume-factive sludge generally forms larger masslike aggregates(Fig.
1–3). There is some degree of overlap in the appear-ance of small
gallstones and sludgeballs and, occasionally,a follow-up sonogram
is helpful in distinguishing thesetwo possibilities. Nonmobile,
nonshadowing structuresrepresent adherent sludge balls or polyps
(Fig. 1–4).13 GBcancer can appear as a polypoid mass and can
potentiallysimulate a benign polyp or tumefactive sludge (Fig.
1–5A).Detection of mobility and vascularity is important in
dis-tinguishing these possibilities (Fig. 1–5B,C).
As already indicated, the documentation of acousticshadowing is
very important in the differential diagnosisof gallstones. To
optimize the detection of acoustic shad-owing requires a transducer
of the highest possible fre-quency focused at the depth of the
gallstone. Changes inthe patient’s position may help by clumping
multiplestones together and thereby increasing the collective
at-
1 Right Upper Quadrant Pain 5
Table 1–3 Sensitivity of Imaging Tests for Gallstones
Test Sensitivity (%)
Radiography 15
Computed tomography 80
Oral cholecystography 65 to 90
Ultrasound 95
AQ2
AQ3
AQ4
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A B
Figure 1–1 Typical gallstone. (A) Longitudinal scan shows a
shadow-ing echogenic structure (arrow) near the neck of the
gallbladder. (B)Longitudinal scan with the patient in a left
lateral decubitus position
documents mobility of this stone (arrow), which is now seen in
thebody of the gallbladder.
Figure 1–2 Small nonshadowing gallstones. (A) Longitudinal
scanusing a 4 MHz transducer shows several small (2 mm)echogenic
foci in the fundus of the gallbladder. No acoustic shadow-ing is
apparent. (B) Longitudinal scan using a 7 MHz linear array
trans-ducer shows similar findings. Although this sonographic
appearancecan, in general, be seen with sludge and stones, it is
common to beunable to detect shadowing in stones this small. It is
very uncommonfor sludge to aggregate into multiple, small,
well-formed foci like this.
A
B
A B
Figure 1–3 Tumefactive sludge. (A) Longitudinal scan with the
pa-tient in a supine position demonstrates a nonshadowing
masslikestructure (s) in the gallbladder neck. The differential
diagnosis basedon this single image is primarily that of a
gallbladder tumor versus
tumefactive sludge. (B) Longitudinal scan with the patient
sittingdocuments mobility of this mass (s) and confirms that it
representstumefactive sludge.
-
tenuation. Changing the transducer position may alter thetissues
displayed behind the GB and make shadowing eas-ier to
visualize.
Although sonography is very good at detecting gall-stones,
false-negative exams do occur. Up to one out of 20
patients with gallstones will be missed by sonography.Therefore,
if the clinical suspicion is extremely high, it isreasonable to do
a follow-up ultrasound after a negativeultrasound. Reasons for a
false-negative ultrasound examinclude a contracted GB (Fig. 1–6), a
GB in an anomalous orunusual location, small stones, stones
impacted in the GBneck or cystic duct (Fig. 1–7), immobile
patients, obese pa-tients, or patients with extensive RUQ bowel
gas.
Once gallstones are documented in a patient with RUQpain, the
next issue is whether the patient should undergocholecystectomy. If
the RUQ pain is clinically consistentwith biliary colic, then ∼40%
of patients will have contin-ued symptoms and 25% will have
worsening symptoms.Because of this, surgery is ultimately necessary
in ∼45% ofthese patients.4 The percentage of patients opting for
sur-gery is likely to go up now that laparoscopic cholecystec-tomy
is so widely available. Surgery is usually performedwhen the
episodes of biliary colic are frequent or severeenough to seriously
interfere with a patient’s lifestyle orwhen there is a history of
complications such as acutecholecystitis, pancreatitis, or
cholangitis.
As with biliary colic, sonography is very valuable in pa-tients
presenting with suspected acute cholecystitis. Sono-graphic
findings in acute cholecystitis are (1) gallstones,
1 Right Upper Quadrant Pain 7
Figure 1–4 Gallbladder polyp. Transverse view demonstrates
asmall, round, nonshadowing lesion arising from the
nondependentwall of the gallbladder (arrow). Views in multiple
positions docu-mented the lack of mobility of these lesions, and
the sonographicfindings are typical of a cholesterol polyp.
B
C
Figure 1–5 Gallbladder carcinoma. (A) Longitudinal view of
thegallbladder demonstrates shadowing stones (straight arrow)
andnonshadowing echogenic material (curved arrow) in the
dependentportion of the gallbladder. The straight border between
this mate-rial and the lumen of the gallbladder simulates the
appearance oflayering sludge. (B) Longitudinal power Doppler image
documentsthe presence of internal vascularity within this echogenic
materialand confirms that this represents vascularized soft tissue
rather thanlayering sludge. Its lack of mobility was demonstrated
on uprightviews. (C) Doppler waveform analysis documents arterial
flowwithin the mass, which was histologically confirmed to
representgallbladder carcinoma.
A
-
I The Abdomen8
A B
Figure 1–7 Cystic duct stones. (A) Initial longitudinal view of
thegallbladder demonstrates a contracted gallbladder (gb) but no
evi-dence of gallstones. (B) Repeat view of the gallbladder (gb)
betterdemonstrates the gallbladder neck and cystic duct
(arrowheads) andconfirms the presence of two small gallstones
(arrows) within the
cystic duct. Stones in this location are one potential cause of
false-negative sonograms. For this reason, careful attention to the
gall-bladder neck is very important during real-time scanning.
(FromKurtz AB, Middleton WD, eds. Ultrasound: The Requisites. St.
Louis:Mosby Yearbook; 1996. Reprinted with permission.)
A B
C
Figure 1–6 Contracted gallbladder filled with multiple small
stones.(A) Longitudinal view of the right upper quadrant
demonstrates a re-gion of clean shadowing (s) adjacent to the
inferior edge of the liver.Note the echogenic linear structure
(arrow) that extends from theshadowing focus to the region of the
portal hepatis. This echogenicline represents the interlobar
fissure. (B) Transverse scan through theliver identifies the
interlobar fissure (arrow) separating the left (L) andright (R)
lobes of the liver. (C) Transverse scan obtained
immediatelyinferior to the level shown in (B) confirms that the
echogenic shad-owing structures (curved arrow) arise immediately
inferior to theinterlobar fissure. In addition, this image
demonstrates the wall-echo-shadow complex that is typical of
gallstones within a con-tracted gallbladder. Although stones are
more difficult to diagnose ina completely contracted gallbladder,
this case illustrates that carefulscrutiny of the expected region
of the gallbladder fossa can usuallyidentify stones even in a very
contracted gallbladder. s, shadow.
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(2) GB wall thickening of greater than 3 mm, (3) GB en-largement
greater than 4 � 10 cm, (4) positive sonographicMurphy’s sign, (5)
pericholecystic fluid, and (6) impactedgallstones. The diagnostic
value of several of the most im-portant individual findings is
shown in Table 1–4.14,15 Thediagnostic value of different
combinations of these find-ings is shown in Table 1–5.
Approximately 95% of cases of acute cholecystitis arerelated to
cystic duct obstruction due to gallstones. There-fore, detection of
gallstones is very important in the sono-graphic diagnosis of acute
cholecystitis. In most cases,freely mobile stones will be seen in
the GB lumen, and theactual obstructing stone in the cystic duct
will not be seen.When a stone is impacted in the GB neck, it is
usually visi-
ble. Occasionally, small stones impacted in the cystic ductcan
also be detected. Acalculous cholecystitis may occur inextremely
sick patients following major surgery, serioustrauma, extensive
burns, or prolonged parenteral nutri-tion. Therefore, in this
patient population the absence ofstones is not a reliable means of
excluding the diagnosis,and secondary sonographic signs of
cholecystitis, de-scribed later, must be relied upon. Although some
centershave reported good results in the sonographic diagnosis
ofacalculous cholecystitis,16 it is often a difficult diagnosis
tomake or exclude by sonography or any other means.
GB wall thickening (defined as 3 mm or greater) occursto some
degree in the majority of cases of acute cholecys-titis (Fig. 1–8).
The positive predictive value of gallstonesand wall thickening is
as high as 94%. However, it is impor-tant to remember that
asymptomatic gallstones are com-mon and there are many causes of GB
wall thickening be-sides cholecystitis (Table 1–6). In fact, the
nonbiliary
1 Right Upper Quadrant Pain 9
Table 1–4 Analysis of Single Sonographic Criteria for
Diagnosisof Acute Cholecystitis
Sensitivity Specificity PPV NPV(%) (%) (%) (%)
Stones 83–98 52–77 86 96
Positive 75–94 85–87 88 72Murphy’s sign
Thickened 45–72 76–88 84 56gallbladder wall
Source: Reprinted with permission From Laing FC, Federle MP,
JeffreyRB, Brown TW. Ultrasonic evaluation of patients with acute
right up-per quadrant pain. Radiology 1981;140:449–455 and Ralls
PW, Col-letti PM, Lapin SA, et al. Real time sonography in
suspected acutecholecystitis: Prospective evaluation of primary and
secondary signs.Radiology 1985;155:767–771 in which the prevalence
of acute chole-cystitis was 35 and 62%, respectively.
PPV, positive predictive value; NPV, negative predictive
value.
Table 1–5 Predictive Values of Multiple Sonographic Criteriafor
Diagnosis of Acute Cholecystitisa
Sonographic Predictive Findings Value (%)
Positive
Stones and positive Murphy’s sign 90
Stones and thickened gallbladder wall 94
Stones, positive Murphy’s sign, and 92thickened gallbladder
wall
Negative
No stones and negative Murphy’s sign 97
No stones and normal gallbladder wall 98
No stones, negative Murphy’s sign, and normal gallbladder wall
99
Source: Reprinted with permission from Ralls PW, Colletti PM,
LapinSA, et al. Real time sonography in suspected acute
cholecystitis:prospective evaluation of primary and secondary
signs. Radiology1985;155:767–771. Data were obtained from a patient
populationwith a 62% prevalence of acute cholecystitis.
Figure 1–8 Acute cholecystitis with gallbladder wall
thickening.Longitudinal view of the gallbladder demonstrates two
stones (s) inthe gallbladder. The gallbladder wall is diffusely
thickened (arrows).This patient also demonstrated a positive
sonographic Murphy’ssign, and these findings are typical of acute
cholecystitis. (From KurtzAB, Middleton WD, eds. Ultrasound: The
Requisites. St. Louis: MosbyYearbook; 1996. Reprinted with
permission.)
Table 1–6 Causes of Gallbladder Wall Thickening
Biliary Nonbiliary
Cholecystitis Hepatitis
Adenomyomatosis Pancreatitis
Cancer Heart failure
Acquired immunodeficiency Hypoproteinemiasyndrome
cholangiopathy
Sclerosing cholangitis Cirrhosis
Portal hypertension
Lymphatic obstruction
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wall thickening, assessment of the sonographic Murphy’ssign is
critical. Hepatobiliary scintigraphy is also an ex-tremely valuable
technique in this type of situation (Fig.1–9).
GB enlargement is also commonly present in patientswith
cholecystitis (Fig. 1–10A). The upper limits of normalfor the size
of the GB are 8 to 10 cm in length and 4 to 5 cmin width. The width
is clearly the more important dimen-sion due to the normal
variation in GB length. In otherwords, a long, thin GB is much less
worrisome than a short,wide GB.
Pericholecystic fluid is present in ∼20% of patients withacute
cholecystitis (Fig. 1–11). Recognizing this fluid is im-portant
because it implies a more advanced case of chole-cystitis. It is
usually seen as a focal collection adjacent tothe GB wall. It
should be distinguished from GB walledema, which is more
concentric, and pericholecystic as-cites, which is less masslike
and conforms to the shape ofthe GB and adjacent structures. In
addition to sonography,CT is occasionally very helpful in
determining the full ex-tent of pericholecystic fluid collections.
Although CT israrely used as the initial imaging test in patients
with sus-pected acute cholecystitis, it can provide useful
informa-tion in cases of complicated cholecystitis that are
difficultto fully sort out with sonography. CT can also be useful
indistinguishing complicated cholecystitis from GB carci-noma.
In addition to pericholecystic fluid, other signs of
com-plicated cholecystitis include sloughed mucosal mem-branes (a
rare finding), localized disruption of the mucosallayer of the GB
wall (Fig. 1–12), striated intramural sonolu-cencies (Fig. 1–13),
frank perforation of the GB (Fig. 1–14),and intramural gas (Fig.
1–15). Patients with these find-
causes of GB wall thickening are generally the source ofthe most
dramatic GB wall thickening. In patients withsuspected acute
cholecystitis and sonographic findings ofgallstones and wall
thickening, it is important to deter-mine if there are possible
nonbiliary causes for the thickGB wall. If there are other
potential explanations for the
I The Abdomen10
A B
Figure 1–10 Acute cholecystitis with gallbladder enlargement.
(A)Longitudinal view of the gallbladder in a left lateral decubitus
posi-tion demonstrates sludge (sl) and stones (s) in the
gallbladder fundusas well as mild wall thickening. The gallbladder
is also enlarged,
measuring 5 to 12 cm in size. (B) Longitudinal view of the
gallbladderin an upright position demonstrates mobile sludge (sl)
and stones (s)but also shows a stone impacted in the gallbladder
neck/cystic duct(curved arrow).
Figure 1–9 Gallbladder wall thickening not due to acute
cholecysti-tis. Transverse view of the gallbladder demonstrates
diffuse wallthickening (arrows) and a gallstone (s). This patient
had congestiveheart failure and diffuse right upper quadrant
tenderness. The gall-bladder wall thickening was felt to be related
to either acute chole-cystitis or congestive heart failure.
Gallbladder scintigraphy wasrecommended for further evaluation. It
demonstrated normal fillingof the gallbladder, thus excluding acute
cholecystitis as the cause ofthis patient’s thick gallbladder
wall.
-
1 Right Upper Quadrant Pain 11
Figure 1–11 Cholecystitis with pericholecystic fluid.
Longitudinalview of the gallbladder in a patient in the intensive
care unit demon-strates sludge (sl) and a stone (s) in the
gallbladder lumen. Also seenis loculated pericholecystic fluid (f)
around the gallbladder fundusand over the anterior surface of the
liver (l). Figure 1–12 Cholecystitis with mucosal disruption.
Longitudinal
view of the gallbladder demonstrates intraluminal sludge (sl)
andstones (s). In addition, there is a region of mucosal disruption
(arrow)along the superior wall of the gallbladder with fluid
dissecting be-neath the mucosa. This is a sign of complicated
cholecystitis and in-dicates gallbladder wall necrosis. (From Kurtz
AB, Middleton WD,eds. Ultrasound: The Requisites. St. Louis: Mosby
Yearbook; 1996.Reprinted with permission.)
Figure 1–13 Acute cholecystitis with gallbladder wall
necrosis.Transverse view of the gallbladder demonstrates stones (s)
layeringin the dependent portion of the gallbladder. Wall
thickening with stri-ated intramural sonolucencies (arrows) is
detected along the lateralgallbladder wall. Although striated
intramural sonolucencies are typ-ically seen in patients with
gallbladder wall thickening due to sourcesother than acute
cholecystitis, in the setting of acute cholecystitis,this
appearance suggests gallbladder wall necrosis. (From Kurtz
AB,Middleton WD, eds. Ultrasound: The Requisites. St. Louis:
MosbyYearbook; 1996. Reprinted with permission.)
Figure 1–14 Acute cholecystitis with perforation. Longitudinal
viewof the gallbladder (gb) shows a well defined defect in the
anterior wall(arrows). A fluid collection (f) is seen dissecting
into the liverparenchyma.
-
tive when pressure applied with the transducer elicits
ten-derness only over the GB or when maximum tenderness islocated
over the GB. A convincingly positive Murphy’s signis strong
evidence of acute cholecystitis. The combinationof gallstones and a
positive sonographic Murphy’s sign hasa positive predictive value
as high as 90%. A negative sono-graphic Murphy’s sign is less
helpful. Causes of a false-neg-ative Murphy’s sign include patient
nonresponsiveness,pain medication, or inability to press directly
on the GB(due to excessive ascites, a GB that is positioned very
deepto the liver or a GB that is located deep to the ribs).
Anotherimportant cause of a negative Murphy’s sign is GB
wallnecrosis (Fig. 1–16). This occurs presumably due to dam-age to
the GB innervation.17 When the Murphy’s sign is dif-ficult to
assess, scintigraphy can be helpful in determiningthe significance
of morphological changes seen on sonog-raphy.
The other major means of imaging patients with sus-pected acute
cholecystitis is hepatobiliary scintigraphy.Scintigraphy is an
excellent means of determining patencyof the cystic duct and
presence or absence of acute chole-cystitis. Sensitivity of
cholescintigraphy has been reportedto range from 86 to 97% and
specificity from 73 to 100%.18–24
Sonographic sensitivity ranges from 81 to 100%, and speci-ficity
ranges from 60 to 100%.14,19–21,24 The bulk of evidenceindicates
that sensitivity and specificity of sonography andscintigraphy are
very similar. Therefore, the choice of ini-tial imaging modalities
is often made based on the prefer-ences of the referring clinician
and local expertise of theradiologist. Although either approach is
acceptable, thereare several good reasons to start the imaging
evaluationwith sonography.
ings of gangrenous cholecystitis have a higher morbidityand
mortality than patients with uncomplicated cholecys-titis and
require either or both more aggressive medicaltreatment and more
urgent surgical treatment.
The sonographic Murphy’s sign refers to localized ten-derness
directly over the GB. This sign is considered posi-
I The Abdomen12
Figure 1–15 Emphysematous cholecystitis. Longitudinal view of
thegallbladder demonstrates very bright reflectors (curved arrow)
in thenondependent portion of the gallbladder wall. A dirty shadow
(s) isseen deep to these bright reflectors. In addition, a ring
down artifact(straight arrows) is identified. The ring down
artifact is pathogno-monic of gas and allows for a confident
diagnosis of emphysematouscholecystitis.
A B
Figure 1–16 False-negative sonographic Murphy’s sign in the
set-ting of gallbladder wall necrosis. (A) Longitudinal view of the
gall-bladder with the patient supine demonstrates sludge (sl) in
thelumen of the gallbladder. In addition, a gallstone is seen in
the regionof the gallbladder neck (curved arrow). (B) Similar view
with the pa-
tient standing upright demonstrates migration of the sludge (sl)
intothe gallbladder fundus but no motion of the stone (curved
arrow) inthe gallbladder neck. This suggests stone impaction in the
gallblad-der neck. Mild gallbladder wall thickening is also
present.
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1. Most patients with acute RUQ pain do not have
acutecholecystitis. Sonography can rapidly exclude the diag-nosis
of cholecystitis by showing a stone-free GB (Fig.1–17 and Fig.
1–18).
2. Sonography is more likely to provide an alternative
di-agnosis14,19 than is scintigraphy (Fig. 1–17 and Fig. 1–18).
3. Sonography is more capable of establishing the pres-ence of
symptomatic gallstone disease in patients withbiliary colic (Fig.
1–19) but without acute chole-cystitis.21 In fact, the positive
predictive value of sonog-
raphy for detecting patients who need a cholecystec-tomy is
∼99%.15 Occasionally, sonography may falselyclassify patients with
symptomatic gallstones as hav-ing acute cholecystitis, but the
impact of this type offalse-positive diagnosis is minimal because
laparo-scopic cholecystectomy is a well-accepted treatmentfor
biliary colic and chronic cholecystitis.
4. Sonography can provide important preoperative infor-mation
that is not readily available from scintigraphy(Fig. 1–20). This
includes information about the size of
1 Right Upper Quadrant Pain 13
C
Figure 1–16 (Continued) (C) Transverse view of the gallbladder
demon-strates an area of mucosal disruption (arrow) with a small
amount of fluiddissecting beneath the mucosa. This patient
presented as an outpatientwith vague upper abdominal pain and a
negative Murphy’s sign. Althoughacute cholecystitis was not a major
clinical consideration, the morpholog-ical changes seen on
sonography in conjunction with a negative Murphy’ssign suggested
acute cholecystitis with necrosis. Based on this, the pa-tient was
operated on later that day, and the sonographic findings
wereconfirmed.
A B
Figure 1–17 Ruptured hepatocellular carcinoma masquerading
asacute cholecystitis. (A) Longitudinal view of the right upper
quadrantin a patient with resolving right upper quadrant pain
demonstrates anormal gallbladder (gb) without evidence of stones or
wall thicken-ing. (B) Longitudinal view of the superior aspect of
the liver (l)demonstrates an inhomogeneous mass (m) adjacent to the
liver cap-
sule. Echogenic blood clot (c) is seen between the liver and the
ab-dominal wall (w). Echogenic ascites was also seen in the pelvis
onother views. Based on the sonographic findings, a diagnosis of a
rup-tured hepatic mass with hemoperitoneum was made. The patientwas
then taken to the operating room where a ruptured hepatocellu-lar
carcinoma was confirmed.
-
or a positive hepatobiliary scan (see reason number 4above). On
the other hand, positive and negative sono-grams do not need to be
followed by scintigraphy.
The ACR guidelines for imaging patients with suspectedacute
cholecystitis indicate that either sonography orscintigraphy is
appropriate. However, sonography is givena higher score than
scintigraphy for the reasons already in-dicated. Practice
guidelines issued in 1988 by the Ameri-can College of Physicians
also recommended using sonog-
the GB and the size of the largest stone, the appear-ance of the
GB wall, the presence of pericholecysticfluid, the presence of
common bile duct stones, andthe status of adjacent organs
(especially liver, rightkidney, and pancreas). This information is
more impor-tant in the current era of laparoscopic surgery
becausethe surgeon is no longer able to carefully inspect
andpalpate the upper abdominal organs.
5. It is common to do sonography after either a
negativehepatobiliary scan (see reasons number 2 and 3 above)
I The Abdomen14
Figure 1–18 Ruptured duodenal ulcer simulating acute
cholecysti-tis. (A) Longitudinal view of the gallbladder (gb)
demonstrates no ev-idence of gallstones. Ascites (a) is seen in the
perihepatic region. (B)Longitudinal scan in the peripyloric region
demonstrates marked
thickening of the bowel wall (cursors). This was interpreted as
repre-senting either neoplastic infiltration or inflammatory
thickening dueto ulcer disease. The patient was subsequently shown
to have a per-forated duodenal ulcer.
A B
A B
Figure 1–19 Symptomatic gallstone disease without evidence
ofacute cholecystitis. (A) Longitudinal view of the gallbladder
demon-strates multiple stones (s), mild gallbladder wall
thickening, and mildgallbladder contraction. At the time this
patient was scanned, therewas no localized tenderness over the
gallbladder. However, she hadpreviously experienced a severe
episode of right upper quadrant pain
that lasted for 3 hours and was now resolving. (B) Longitudinal
viewof the normal diameter distal bile duct (arrows) demonstrates a
shad-owing echogenic focus (curved arrow) consistent with a small
distalcommon bile duct stone. This provides convincing evidence
that thepatient’s recent pain was due to biliary colic as a stone
passedthrough the cystic duct and into the common bile duct.
AQ6
-
raphy as the first imaging test for suspected acute
chole-cystitis.25,26 Although both of these groups prefer to
startwith sonography in the evaluation of patients with sus-pected
acute cholecystitis, scintigraphy should be recog-nized as a
powerful problem solver when the sonogram isconfusing or
inconclusive. This may occur in up to 20% ofpatients with
clinically suspected acute cholecystitis inwhom ultrasound is done
first. Therefore, cholescintigra-phy continues to play an important
role in the evaluationof acute cholecystitis.
Treatment for acute cholecystitis can initially be conser-vative
with pain medication, IV hydration, and antibiotics.Approximately
75% of patients will respond to medicaltherapy. The rest either
will be refractory to conservativetreatment or will develop
complications and require sur-gery. Of the patients that initially
respond to medical treat-ment, recurrent cholecystitis will occur
within 1 year in25% and within 6 years in 60%. Therefore, the
current ap-proach is to perform cholecystectomy during or after
thefirst episode of acute cholecystitis. The exact timing of
thecholecystectomy is not uniformly agreed upon. It appearsthat
early laparoscopic cholecystectomy is most effective ifperformed on
patients presenting within 48 hours of theonset of symptoms. Early
cholecystectomy may also benecessary if the patient fails to
respond to medical treat-ment. Delayed cholecystectomy is generally
reserved forpatients presenting after 48 hours, for those patients
at in-creased operative risk, or for those patients in whom
thediagnosis is unclear. Emergent cholecystectomy is reservedfor
patients that are clinically unstable or patients withcomplications
identified clinically or on imaging studies.
Summary
Sonography is the primary imaging modality for evalua-tion of
RUQ pain. It is more effective at diagnosing andevaluating
gallstones than any other imaging test. OCGhas been largely
abandoned. However, gallstones are wellquantified by OCGs and if
dissolution therapy or litho-tripsy become more popular in the
future, OCG may be-come more important. Sonography is similar in
accuracyto scintigraphy in the evaluation of suspected
acutecholecystitis and provides additional information that isnot
available on scintigraphy. Cholescintigraphy is a valu-able test of
GB function that is very useful in the evalua-tion of suspected
acute cholecystitis when ultrasound isconfusing or indeterminate.
CT is not a primary modalityin the evaluation of RUQ pain but is
very useful in furtherevaluating complicated cholecystitis and GB
neoplasm.CT may be useful in the diagnosis of acute
acalculouscholecystitis.
References1. Hopper KD, Landis JR, Meilstrup JW, McCauslin MA,
Sechtin AG.
The prevalence of asymptomatic gallstones in the general
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3. Gracie WA. The natural history of silent gallstones: the
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4. McSherry CK, Ferstenberg H, Calhoun WF, Lahman E, Virshup
M.The natural history of diagnosed gallstone disease in
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5. Ransohoff DF, Gracie WA, Wolfenson LB, Neuhauser D.
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1 Right Upper Quadrant Pain 15
Figure 1–20 Acute cholecystitis with marked intramural fluid
collec-tions. Longitudinal view of the gallbladder demonstrates a
stone (s)impacted in the gallbladder neck. Multiple fluid
collections (f) areseen in the thickened gallbladder wall.
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intramural fluid collection is ap-parent. Identification of this
severe gallbladder wall abnormality pro-vides important
preoperative information to the patient’s surgeon.(From Kurtz AB,
Middleton WD, eds. Ultrasound: The Requisites. St.Louis: Mosby
Yearbook; 1996. Reprinted with permission.)
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21. Worthen NJ, Uszler JM, Funamura JL. Cholecystitis:
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ultra-sonography. Clin Nucl Med 1982;7:364–367
25. No authors listed. How to study the gallbladder: Health and
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26. Marton KI, Doubilet P. How to image the gallbladder in
suspectedacute cholecystitis. Ann Intern Med 1988;109:722–729
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scintigra-phy, and CT. AJR Am J Roentgenol 1986;147:1171–1175
17. Simeone JF, Brink JA, Mueller PR, et al. The sonographic
diagnosisof acute gangrenous cholecystitis: importance of the
Murphy sign.AJR Am J Roentgenol 1989;152:289–290
18. Samuels BI, Freitas JE, Bree RL, Schwab RE, Heller ST. A
comparisonof radionuclide hepatobiliary imaging and real-time
ultrasound forthe detection of acute cholecystitis. Radiology
1983;147:207–210
19. Shuman WP, Mack LA, Rudd TG, Rogers JV, Gibbs P. Evaluation
ofacute right upper quadrant pain: sonography and
99mTcPIPIDAcholescintigraphy. AJR Am J Roentgenol
1982;139:61–64
20. Ralls PW, Colletti PM, Halls JM, Siemsen JK. Prospective
evaluationof 99mTc-IDA cholescintigraphy and gray-scale ultrasound
in thediagnosis of acute cholecystitis. Radiology
1982;144:369–371
I The Abdomen16
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LOC.OK?AQ2 Au: change okay?AQ3 Au: please specify chapter number in
cross reference.AQ4 Au: the subject is “detection,” correct? or do
you mean“Vascularity and detection of mobility are important . . .
“?AQ5 Au: legend for figure 1-16 says false-negative, not
negative.Please reconcile.AQ6 Au: please spell out first use of
ACR.AQ7 Au: Ref. 24, changed as meant?AQ8 Au: 5d changed as
meant?
AQ7