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

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

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.

(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

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.

AQ5

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)

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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.

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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 popula-tion. Invest Radiol 1991;26:939–945

2. Lee SP, Kuver R. Gallstones. In: Yamada T, ed. Textbook of Gastroen-terology. 2nd ed. Philadelphia: JB Lippincott; 1995:2187–2212

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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. Communication between thegallbladder lumen and the anterior 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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23. Weissmann HS, Badia J, Sugarman LA, et al. Spectrum of 99mTc-IDA cholescintigraphic patterns in acute cholecystitis. Radiology1981;138:167–175

24. Freitas JE, Mirkes S, Fink-Bennett DM, Bree RL. Suspected acutecholecystitisocomparison of hepatobiliary scintigraphy and ultra-sonography. Clin Nucl Med 1982;7:364–367

25. No authors listed. How to study the gallbladder: Health and PolicyCommittee. Ann Intern Med 1988;109:752–754

26. Marton KI, Doubilet P. How to image the gallbladder in suspectedacute cholecystitis. Ann Intern Med 1988;109:722–729

15. Ralls PW, Colletti PM, Lapin SA, et al. Real time sonography in sus-pected acute cholecystitis: prospective evaluation of primary andsecondary signs. Radiology 1985;155:767–771

16. Mirvis SE, Vainright JR, Nelson AW, et al. The diagnosis of acuteacalculous cholecystitis: a comparison of sonography, 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

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AQ1 Au: Removing middle initial D. for consistency with 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?

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