Although emphysematous cholecystitis may be diagnosed with the aid of plain radiography of

the liver and upper abdomen, computed tomography is helpful in confirming the diagnosis and

describing the extent of the disease preoperatively (Poleynard and Harris). Also, as in the case of

ultrasound, computed tomography with enhancement by the injection of meglumine diatrizoate

may show the gallbladder wall to be thickened and enlarged, and often there are associated

stones responsible for the acute cholecystitis. Certainly it is believed by Solomon and associates

that computed tomography has a distinct place in the assessment of acute inflammation of the

gallbladder. Similar positive results were reported by Havrilla and co-workers.

Computed tomography has also been found valuable in the diagnosis of gallbladder

carcinoma (Fig. 4—59) (Itai et al; Yeh). Of 27 patients with gallbladder carcinoma studied by

Itai and associates, the lesion was suggested in 26 computed tomographs. The gallbladder cancer

was described as massive, thickened wall, or intraluminal; 20 of their 27 cases were diagnosed

correctly as cancer. There were misleading signs in 3. They reported that some cases of chronic

cholecystitis and liver tumor were difficult to differentiate from gallbladder cancer. Likewise

lymph node metastases and bile duct extension were difficult to distinguish.

Yeh utilized both ultrasonography and computed tomography for the diagnosis of

carcinoma of the gallbladder, with ultrasonography being performed on 14 patients and

computed tomography on 7. Frequently there were associated gallstones, dilated bile ducts, or

metastatic lesions in the liver or retroperitoneal lymph nodes. The diagnosis was made or

suggested by ultrasonography in 84.6 per cent of the 14 patients, and the computed tomography

corrfelated well with ultrasonographic features.

Pneumobilia

Gas in the biliary tree may of course be well demonstrated by plain radiography, of the

upper abdomen if the patient is kept erect for approximately 5 minutes. On the other hand,

computed tomography, ultrasound, and radionuclide scans have also been helpful and were

studied in 25 patients with biliary-enteric anastomoses by Grant and associates. These patients

are also particularly frequently studied for metastatic disease. The demonstration of the

metastatic disease is an important reason for utilization of computed tomography and

radionuclide scanning. There were no discrepancies in this study among radionuclide studies,

computed tomography, and ultrasound diagnoses of liver metastases.

A good overview of this entire subject has been presented by Kreel.

Hepatic Contrast Agents for Computed Tomography

Seltzer and associates have made a special study to identify, design, synthesize, and test

new particulate contrast agents of high atomic numbers that might be useful for computed

tomography.

Their search was directed to substances that would be highly selective for the liver. They

utilized suspensions of cerium, gadolinium, and dysprosium oxide, as well as silver iodide

colloid. All four experimental agents were selectively concentrated in the reticuloendothelial

system of rats and rabbits and produced greater and longer opacification of normal livers and

large liver-to-tumor differences in rabbits with hepatic tumors. Lesions as small as 5 mm were

visible with computed tomography. It is possible, however, that the toxicity of these agents as

well as their long-term retention may limit their clinical utilization.

Summary

Although most investigators have a favorable early experience with computed tomography

in the evaluation of the liver and biliary tract and suggest that it has a very promising future in

replacing more invasive types of diagnostic procedures, the limitation of the various scanners

and the display is still a great one. Models of computed tomographs that are capable of

reconstructing coronal or sagittal planes from contiguous cross-sectional data will probably

improve the applications of computed tomography significantly. The exact role that computed

tomography will ultimately play in diagnosis is yet to be demonstrated.

It is interesting that despite the disadvantage of ionizing radiation a comparative study of

diagnoses from computed tomographic and ultrasonic examinations of the abdomen in 29

pediatric patients showed computed tomography to have a significant advantage over ultrasound

in the differential diagnosis of abnormal cases. Of the 29 cases, a correct diagnosis was possible

by both modalities in all but 3 instances. Findings from each technique considered separately

would have resulted in erroneous diagnoses in 4 instances using computed tomography and 9

using ultrasound alone. The 2 examinations, therefore, were considered complementary (Brasch

et al).

Biliary Angiography (Deutsch; Farrell; Ruzicka and Rossi; Rosch; Redman and Reuter)

(Fig. 4-63)

Visualization of the gallbladder by selective celiac and mesenteric angiography during

selective aortography shows the normal gallbladder to have a wall thickness of 2 to 3 mm six to

eight seconds after visualization of the cystic artery. Contrast medium has to be directed into the

hepatic artery for this to be shown.

Normal Gallbladder Measurements

The normal measurements of the gallbladder were derived angiographically by Redman

and Reuter from 25 normal gallbladders and are presented in Table 4-8. They concluded that

gallbladders measuring more than 35 sq cm or those having a diameter of more than 5 cm may

be considered distended.

Others have been able to study the angiographic pattern of carcinoma of the gallbladder

(Deutsch, 5 cases), hydrops, empyema, and chronic cholecystitis.

It is thought that the angiographic demonstration of a dilated gallbladder should lead the

physician to search for other abnormalities to explain its presence, particularly if there is

obstructive jaundice present; however, oral cholecystography, being a different examination,

cannot be evaluated in this manner.

Figure 4-63. Cystic artery variations. In A the solid vessel line indicates the most frequent site of origin of the cystic artery. The interrupted vessel lines show the more common variations. In B, the cystic artery arises from the right hepatic, which is a branch of the superior mesenteric artery. In C, three of the more common variations of double cystic arteries are shown. (From Ruzicka FF Jr, Rossi P: Radiol Clin North Am 8:3-29, 1970.)

Hepatic angiography was performed following the percutaneous transhepatic

catheterization of the hepatic vessels by Hoevels and Nilsson. Vascular lesions of the liver were

demonstrated in 27 of 83 patients. These included aneurysm, hematoma, ar- terioportal venous

fistula, arteriohepatic venous fistula. No clinical complications were observed in 22 of these 27

cases. One patient needed a blood transfusion. In 4 patients with severe hemorrhage from an

intrahepatic aneurysm, transcatheter embolization was performed. Two of their patients died

within 72 hours because of liver insufficiency.

Specific Diseases of the Hepato- ' Biliary-Gallbladder System

CHOLELITHIASIS

Cholelithiasis is indeed a major medical problem. It is estimated that in the United States

alone, 20 million people have gallstones and each year 500,000 undergo cholecystectomy

(Schoenfield). In patients with sickle cell disease the incidence ranges from 10 to 37 per cent

and increases with age (Phillips and Gerald). It is possible that this incidence is even greater in

those with sickle cell disease than has been previously reported (Phillips and Gerald). The

clinical history and laboratory findings may be very nonspecific (probably 15 per cent). Another

30 per cent will probably have specific biliary symptoms, and some 50 per cent of patients will

have gallstones at autopsy which escaped detection during their lifetime (Key and Wechsler).

When clinical manifestations are present, the three basic symptoms are biliary colic,

cholecystitis, and cholangitis. Many nonspecific symptoms are blamed on gallstones, which

prove not related directly to gallstone disease, such as fatty food intolerance, dyspepsia, pyrosis,

belching, and bloating.

Biliary colic is perhaps a misnomer, since actually it is a steady severe pain of sudden onset

usually requiring a narcotic for relief, rising rapidly to a plateau, which remains*steady for 20

minutes to even three hours. Perhaps in about 40 per cent of cases these episodes last less than

one hour. It rarely waxes and wanes as the “colic” would indicate. The patient moves about

greatly with this pain unlike other acute abdominal surgical episodes. Generally, this pain will

subside in about three- quarters of patients within three days or actually progress in one-quarter

to perforation or gangrene of the gallbladder.

Pathogenesis and Risk Factors (Coyne et al, a, b, c)

There are three stages in the formation of gallstones: (1) saturation of bile with cholesterol,

(2) crystal formation and (3) aggregation of these crystals to form gallstones. The cholesterol in

stage 1 is secreted by the liver and maintained in solution by the bile itself, bile acids, and

lecithin, which are also secreted by the liver.

Generally, patients with gallstones have a decreased amount of bile acid in comparison with

normal controls (Holzbach). Moreover, patients with gallstones have decreased hepatic bile acid

synthesis compared with normal subjects; and patients with gallstones have a greater cholesterol

secretion for a given amount of bile acid secretion than patients without gallstones (Grunde et

al). Moreover, there is an increased hepatic cholesterol synthesis in these patients. In summary,

then, the defect in gallstone patients seems to be (1) small bile acid pool with an inappropriately

decreased rate of bile acid synthesis in the liver and (2) increased hepatic cholesterol synthesis

and increased cholesterol secretion into the body. These represent 80 per cent of the gallstones

in the United States, the remainder being calcium bilirubinate.

The incidence of gallstones is higher in women than in men (Holland and Heaton). Oral

contraceptives increase the cholesterol saturation of bile in young women without gallstones

(Bennion et al). Also certain racial groups, such as the American Indians, have a higher

incidence of cholesterol gallstones than the general population (Sampliner et al). Obesity is

another risk factor. Also it has been shown that increasing dietary cholesterol increases the per

cent of cholesterol in bile (DenBesten et al).

How May Gallstones Be Diagnosed Radiographically?

Fifteen per cent of gallstones contain sufficient calcium to be seen on plain films of the

abdomen.

Occasional gallstones are fractured and loosened, with a “Mercedes-Benz sign.”

Oral cholecystography

Nonvisualization of the gallbladder occurs in about 25 to 30 per cent at first examination.

At least two-thirds of those who had non-opacified gallbladders with a first dose will have

opacification with a second dose on the second day. If the bilirubin is over 3 mg per 100

ml, it is unlikely that the gallbladder will opacify under any circumstances.

Ultrasonography may demonstrate the gallbladder in 90 to 95 per cent of normal fasting

patients (Doust and Maklad). The gallstone itself is echogenic, the gallbladder appears

cystlike around it, and there is a sonic shadowing effect beyond the gallstone because of

the poor penetration of the sound waves through the gallstones.

Intravenous cholangiography: if the bilirubin level is over 4 mg per 100 ml it is very

unlikely that the ductal system will opacify (Scholz et al). Tomography is used routinely

with intravenous cholangiography for optimum results. One may opacify the gallbladder

with this technology, obtaining a film of the gallbladder in approximately 4 hours, but

sometimes as late as 24 hours.

Computer assisted tomography.

Endoscopic retrograde cholangiopancreatography (ERCP).

Skinny needle transhepatic cholangiography (PTC).

These methods have all been previously described in considerable detail. Unfortunately,

biochemical evidence of pancreatitis often occurs following ERCP, but this ordinarily lasts only

for several days without incident. Ascending cholangitis with septic shock is a possible

complication of both ERCP and transhepatic cholangiography. Bleeding and bile peritonitis

may be minimal with the latter procedure. Generally, transhepatic cholangiography is successful

in a jaundiced patient about 75 per cent of the time and in the nondilated duct only 25 per cent

of the time. The combined diagnostic accuracy of both procedures is about 93 per cent.

Laparoscopy may help differentiate a normal from an inflamed gallbladder. This may

be helpful in the 20 per cent of jaundiced patients in whom differentiation between

medical and surgical jaundice is otherwise difficult.

Medical Dissolution of Gallstones

Treatment with chenodeoxycholic acid (CDC) induces desaturation of cholesterol saturated

bile in gallstone patients. Worldwide experience with about 2000 patients suggests that 60 per

cent of patients treated with CDC for between 6 months and 2 years will undergo complete

dissolution of their gallstones (Coyne, 1976b). Calcified cholesterol gallstones or pigment

gallstones do not respond. The side effects to CDC treatment are (a) diarrhea, which is dose

related, mild, and often transient; (b) hyperlipide- mia; and as a result, (c) possible

atherogenesis.

Hepatotoxicity may be a major potential problem. Transaminase elevations have been noted

in approximately 20 per cent of patients with CDC.

Nonoperative Treatment of Common Duct Stones

T-tube extraction by iritroducing a special catheter under fluoroscopic control and a

Dormier basket or Fogarty biliary catheter may be performed (Burhenne, 1980).

Endoscopic papillotomy is similar to ERCP, but there is a thin wire connected to an

electrosurgical unit which applies a coagulation current and pulling action. It thereby transects

the sphincter (precisely between 10 and 12 o’clock on the 360-degree scale to avoid injury to

the pancreatic duct or retroperitoneal perforation). Mortality in 472 such cases reported by

Classen was 1.0 per cent or 5 patients. Other complications included hemorrhage (15 patients);

perforation (11 patients); cholangitis (9 patients); and pancreatitis (7 patients).

Operative Management of Common Duct Stones

1. The operative cholangiogram is by far the most accurate indicator of the presence of

ductal stones. A negative cholangiogram unfortunately will miss stones in approximately 14 per

cent of cases (Shore et al, a, b, c).

2. Exploration of the common bile duct is mandatory for acute suppurative cholangitis or a

palpable stone in the duct.

3. Choledochotomy, if necessary, should be performed with a minimum of instrumentation

and manipulation. This may be done by an appropriate fiberoptic scope inserted at the time of

operation. This type of fiberoptic scope may also be utilized for visualization of the major

hepatic duct as well. Extraction of the stones is thereafter feasible.

Chronic Cholecystitis and Cholelithiasis

Chronic cholecystitis is usually associated with cholelithiasis and is characterized by fatty

food intolerance, constant or intermittent postprandial epigastric or right upper quadrant

distress, belching, nausea, vomiting, and flatulence, with or without biliary colic. The

gallbladder may show minimal to severe chronic inflammatory changes even to the point of

calcification of the wall. The gallbladder wall is almost always thickened, and adhesions to

adjacent structures may be present. Gallstones are present in 90 to 95 per cent of the patients

(Palayew; Smeets and Op den Orth). Perforation of the gallstone into adjacent bowel may lead

to chronic cholecystoenteric fistula.

In addition to the previous roentgen findings of radiopaque calculi and the “Mercedes-Benz

sign” on plain films of the abdomen, there may be a soft tissue mass due to a distended

gallbladder; milk of calcium bile in the gallbladder; a calcified or “porcelain” gallbladder, which

is always associated with cystic duct obstruction, and in these instances the calcium lies in the

submucosa; or gas in the gallbladder which is due to either infection or communication with the

gastrointestinal tract.

Barium studies may be helpful in outlining a fistula between the gastrointestinal tract and

the gallbladder; and occasionally there is a pressure defect of the enlarged gallbladder on the

duodenum or on the anterior portion of the hepatic flexure of the colon which has been called

the “pad” sign (Ghahremani and Meyers).

GALLBLADDER AND BILIARY DISEASE IN RELATION TO BOWEL

DISEASE

Oral Cholecystography in Patients with Small Bowel Disease

In a study of 84 patients with proven small bowel disease who later underwent oral

cholecystography (Low-Beer et al) the gallbladder was visualized in 95 per cent. Seventy-five

per cent of the remaining nonvisualized gallbladders contained stones. The patients with small

bowel disease were 5 with Crohn’s disease who had good opacification of the gallbladder and 45

with Crohn’s disease with ileal bypass or resection, 2 of whom had poor visualization of the

gallbladder. The remaining patient with poor visualization of the gallbladder was an adult patient

with celiac disease.

In another related study in patients with ileostomy (Jones et al, 1976), the prevalence of

gallstones was studied in patients with ileostomies, who had undergone surgery for ulcerative

colitis. There were 55 patients in all, and 11 of these were found to have gallbladder disease.

This is considerably higher than the number found in a control population in the same area.

In patients with cystic fibrosis of the pancreas or mucoviscidosis, pathologic findings in

the liver and biliary tract are well known (Rovsing and Sloth; l’Heureux et al). It is well known,

for example, that the gallbladder may be hypoplastic and often has an obstructed cystic duct.

There are numerous mucus- containing cysts within the gallbladder in the submucosa, but

inflammatory changes are notoriously absent. Rovsing and Sloth carried out a study of the

biliary tract in 41 patients with cystic fibrosis. There were changes in 19, consisting of a

microgallbladder in 6 patients and no filling or only partial filling of the biliary ducts in 11

patients. Gallstones were present in one and were probably present in another.

In the study conducted by l’Heureux and associates, 84 consecutive patients with cystic

fibrosis underwent oral cholecystography. This test was abnormal in 46.4 per cent (39 of the

patients). In general, abnormality increased with age. There were 26 patients with a

nonvisualized gallbladder following a sequential two-dose oral cholecystographic technique. Ten

of their patients were found to have calculi, with an incidence of 11.9 per cent.

It may thus be concluded that mucoviscidosis and biliary tract and/or gallbladder disease

of various types often coexist.

The Close Relationship of the Gallbladder to the Hepatic Flexure in Relation to Interpretation of Disease (Ghahremani and Meyers). Since the gallbladder is so closely applied to superior medial aspect of the right flexure of the

colon, there is provision for a direct extension of gallbladder inflammation or its involvement by

neoplasm to the adjacent colon. It has been emphasized that the resultant secondary colonic

abnormalities may be noted and must be carefully analyzed to relate the disease to either

primary biliary tract disease or colonic disease. Actually, in acute cholecystitis, barium enema

examination may show evidence of marked indentation by the enlarged gallbladder with spasm

and mucosal edema in the colon. Chronic cholecystitis may result in involvement of the adjacent

colon by fibrous adhesions and inflammatory reactions. This may further lead to a

“pseudotumor” appearance in the colon resembling even a papillary lesion or primary

carcinoma. Cholecystocolic fistu- lae may occur. This close relationship must be borne in mind

in every instance in which the possibility of gallbladder disease and/or hepatic flexure disease

may exist.

Cholecystographic Diagnoses with Liver Disease

These findings have been to a great extent summarized by Anton (1972); however, the

cholan- giographic findings in diseases of the liver at postmortem study were extensively

reviewed by Legge and associates. There is a considerable spectrum of changes found in the

biliary ducts in association with cirrhosis of the liver, fatty infiltration, or lymphoma and also

with extrinsic displacement and narrowness of the biliary ductal system with metastatic deposits.

The intrahepatic bile ducts are normal in size in many diseases of the liver, including

infiltrative diseases and cirrhosis and when there are small tumor nodules. Changes in the liver

very often result not only from fibrosis and collapse but also from regeneration or increase in

hepatic mass, as occurs with a diffuse infiltration in metastatic tumors. Such changes should

indeed be readily differentiated if these patients might be subjected to transhepatic or T-tube

cholangiography. They are known to exist with primary carcinoma of the bile ducts, sclerosing

cholangitis, cholangitic hepatitis, and large metas- tases. Radiographically the clue should be

displacement of thf biliary radicles, if one is familiar with the exact anatomy of the liver as it

should be portrayed, as well as increased narrowness of the biliary tree following injection.

The bile duct has also been carefully studied in association with chronic pancreatitis and

with sclerosing cholangitis (Wells et al).

Cholecystographic Diagnoses With Pancreatic Disorders

With chronic inflammatory disease of the pancreas, ERCP examinations will demonstrate

not only abnormalities of the pancreatic duct but associated changes in the common bile duct in

perhaps as many as 44 per cent of the patients, suggesting an abnormality perhaps even of the

sclerosing cholangitic variety (Wells et al).

Sclerosing Cholangitis

Sclerosing cholangitis is a rare disorder characterized by nonspecific inflammatory fibrosis

in the submucosa of the biliary tree. This may lead to progressive obstructive jaundice. It is often

associated with another disease, such as ulcerative colitis, Crohn’s disease, retroperitoneal

fibrosis, carcinoma of the pancreas, Riedel’s thyroiditis, or orbital pseudotumor. The ERCP

examination or operative cho- langiogram will usually demonstrate a variation in caliber of the

biliary tree due to areas of smooth narrowness and a tendency toward beading. Ultimately, the

changes include multiple strictures and a “pruned-tree” appearance. These changes may be

generalized or patchy. The findings may indeed be confused with a sclerosing

cholangiocarcinoma, infective cholangitis, primary biliary cirrhosis, post- surgical or traumatic

strictures, and impressions on the intrahepatic duct by multiple hepatic space- occupying lesions,

particularly metastases. One must recall the associated diseases, particularly when the diagnosis

of sclerosing cholangitis is suggested.

Congenital Biliary Atresia

One must recall that congenital biliary atresia is one of the diseases of infancy with a high

incidence of cervical herniation of the lung and bone changes suggestive of rickets. At times

there is a definite generalized demineralization of the bones and metaphysial abnormalities with

fractures at the me- taphyses. There is no good correlation, however, between the bony changes

and the liver dysfunction; and it certainly does not universally occur (8 out of 38 cases in a series

reported by Katayama et al).

Aberrant Insertion of the Common Bile Duct

Among abnormalities of the common bile duct that may be visualized by cholangiography,

aberrant insertion of the common bile duct, particularly into a duodenal diverticulum, must be

kept in mind. This is often associated with biliary and pancreatic disease and can be surgically

relieved (Rose).

Choledochal Cysts

This is a rare malformation of the biliary ductal system and is usually considered an

anomaly. It is sometimes associated with a clinical complex that includes jaundice or a history

suggestive of intermittent jaundice. At times a mass is palpable, particularly in the infant.

Varieties of choledochal cysts have been illustrated (Fig. 4-57).

ACUTE CHOLECYSTITIS

Acute cholecystitis varies considerably in its clinical manifestations from mild transient

episodes of upper abdominal pain to intense prolonged epigastric intermittent colicky pain. Early

effective treatment is essential. There is some variation, however, as to the imaging technique

that gives one the best corroboration of diagnosis. Some would obtain an intravenous

cholangiogram or oral cholecysto- gram if the patient has not had previous biliary studies or

substantiated evidence of biliary disease (Hermann). Infusion tomography of the gallbladder has

strongly been suggested (Katzberg et al). In many instances a gallbladder wall visualization with

a somewhat “fuzzy appearance” is demonstrable by either tomography of the right upper

quadrant or even excretory urography. Even gallstone formation around metallic foreign bodies

has been described as an unusual cause of acute cholecystitis (Sanowski and Arbaje-Ramirez).

Others report that radionuclide studies of the gallbladder and liver are strongly indicated in these

suspected patients (Shaffer et al).

Cholescintigraphy may assess the dynamic events associated with gallbladder filling and

emptying very accurately, particularly when the radionuclide 99mtechnetium HID A

(iminodiacetic acid) is utilized. In these instances the radionuclide is excreted in the bile and not

only visualized by an Anger camera but also programmed for data processing of changes in time

with respect to activity in the liver, biliary ductal system, gallbladder, small intestine, and

stomach. The first 60 minutes are used to detect filling of the gallbladder. Cholecystokinin may

then be infused at 0.020 U/kg/minute for 30 minutes to initiate gallbladder contraction, while the

passage of the radionuclide into the small intestine and/or stomach is monitored. The stomach

region may be defined with scintigraphy utilizing the radionuclide 99mtechnetium-sulfur colloid.

In this manner, the rate at which the gallbladder is filled, the fraction of liver activity that

partitions into the gallbladder instead of the duodenum, and the rate of gallbladder emptying as

well as duodenogastric reflux may be recorded. There may be approximately a 5-minute time lag

between gallbladder emptying and the injection of the cholecystokinin. Gallbladder evacuation is

definitely slower in patients with cholelithiasis, although filling may appear rather normal.

In an update on radionuclide imaging in hepatobiliary disease (Rosenthall, 1978) this

technology was emphasized once again. Indeed, it is claimed that the introduction of 99mtechnetium-labeled 2,6- dimethylacetanilide iminodiacetic acid (HIDA) significantly assists

the clinical study of bile flow. Basically this radionuclide complex is metabolized by the

hepatocyte and excreted into the biliary tract. In the presence of liver failure a greater amount of

the radionuclide is excreted by the kidney. This entire methodology is reviewed by Rosenthall,

and it is outside the scope of this text, except to mention that this is a very important technology

to utilize particularly in the presence of acute cholecystitis. When the gallbladder fills, one may

postulate that a patent cystic duct exists. This effectively excludes the possibility of an acute

cholecystitis, since the precipitating cause of acute cholecystitis is obstruction of the cystic duct

in about 98 per cent of the cases. False negatives rarely occur in the presence of acalculous

cholecystitis, wherein the gallbladder is indeed visualized; but if this is suspected, a slow

infusion of cholecystokinin will demonstrate a failure of normal contraction of the gallbladder.

Therefore, it should be stressed that with this radionuclide technique, nonvisualization of the

gallbladder implies cholecystitis but not necessarily acute cholecystitis. Nonvisualization may

also occur with chronic cholecystitis. The exact reason for this is not known. Rosenthall claimed

that this radionuclide technique is superior to oral cholecystography and intravenous

cholangiography, particularly in patients with acute manifestations of hepatobiliary disease,

since the patency of the cystic duct can be demonstrated in the presence of jaundice and no

pharmacologic hazard exists. Moreover, the study is completed within 60 minutes, and gas and

fecal material do not hinder accurate interpretation.

Moreover, by other techniques it is very difficult to exclude the possibility of acute

pancreatitis; however, the radionuclide study shows all normal gallbladders even in the presence

of acute pancreatitis, especially if there is no associated or coincident chronic cholecystitis.

Unfortunately, the radionuclide techniques do not disclose cholelithiasis unless the stones are

large, because the resolution with the gamma camera is insufficient for this purpose.

Hence, oral cholecystography, ultrasound, or intravenous cholangiography may be used

for these other purposes.

Other uses of this scintigraphic technique are (1) the assessment of cholangiointestinal

anastomoses in gastroenterostomies and (2) the differential diagnosis of jaundice.

Other investigators have substantiated these findings (Pare et al, 1978; Weissman et al,

1979, 1981).

Grading of Severity of Chronic Cholecystitis by Utilization of Oral Cholecystography

(Owen et al). An effort has been made to grade the severity of chronic cholecystitis by the

image density at oral cholecystography by comparison of the densities obtained and the study of

the resulting cholecystectomy specimens. Owen and associates have indicated in their study that

there is a linear relationship between the gallbladder opacification and the grade of chronic

cholecystitis; that the occurrence of gallstones is independent of the degree of gallbladder

opacification; and that the presence of gallstones does not correlate with the severity of chronic

cholecystitis. They have suggested strongly that oral cholecystographic techniques be

standardized, so that uniform grading of the severity of chronic cholecystitis by the gallbladder

image density could be employed.

BENIGN TUMORS AND PSEUDOTUMORS OF THE GALLBLADDER (Table 4-9)

Christensen and Ishak have studied benign tumors and pseudotumors of the gallbladder at

considerable length, reporting on 180 cases. They subdivided these into 24 cases of polyps

consisting of 3 inflammatory and 21 cholesterol polyps and 91 cases of hyperplasia, most of

which were adenomyoma- tosis. These patients were very carefully studied in relation to their

age, sex, and race, as well as symptomatology, and the literature was reviewed. On the basis of

these studies, these authors recommended a simplified classification of benign tumors and

pseudotumors of the gallbladder, as shown in Table 4-9.

RADIOLOGY OF CHOLECYSTECTOMY COMPLICATIONS

Radiographic studies may be valuable in suggesting or confirming a diagnosis postoperatively

following cholecystectomy even when other clinical findings may not be evident. Plain films,

contrast studies, ultrasound, and computed tomography are all useful modalities in this area

(Love et al). Some of the entities to be considered are incisional hernias and infection, which

probably constitute the most important problems; damage to the common bile duct, producing

either jaundice or fistula; problems in relation to the retained cystic duct stump, where there is a

higher incidence of biliary distress, gallstones, adhesions, inflammatory changes and even

neuromas (an elongated cystic duct remnant is found in nearly 70 per cent of severe

postcholecystectomy complaints); drainage tube problems; retained stones within the ductal

system; hepatic artery injuries, particularly when it is not clearly identified at operation, leading

to inadvertent ligation; sub- hepatic accumulations of fluid, probably the most frequent

complication following biliary tract surgery after which it occurs in 5 to 6 per cent of cases;

pancreatitis; and various bowel complications, which are probably the rarest of the

complications. There may be inadvertent damage to the hepatic flexure or the duodenum

particularly. The reader is referred to a comprehensive study of these various complications by

Love and associates.

New Trends In Gallbladder Imaging (Simeone and Ferrucci)

Although a great deal of emphasis is still placed upon oral cholecystography, recent progress

with respect to gray-scale ultrasound, including real-time scanning, has made remarkable

inroads in the diagnosis of the entire spectrum of gallbladder disease.

As noted previously, gallstones are readily detected by ultrasonography. Calculi are

displayed as echogenic foci with a “shadowing” effect almost universally (Hublitz et al). The

predictive accuracy of cholelithiasis when a shadowing effect is produced is somewhere

between 95 and 98 per cent even with millimeter-sized calculi. With the nonvisualized gall-

bladder by oral cholecystography, the predictive accuracy of the presence of cholelithiasis with

ultrasonography is on the order of 90 per cent. In some instances, there is no shadowing effect

by the gallstone, and under these circumstances the predictive accuracy is estimated at 80 per

cent. Sludge or milk of calcium bile (not the same entity) in the gallbladder is visualized with an

accuracy of somewhere between 0 and 5 per cent. The various patterns may be typified as

follows: At times the gallstone may be visualized as an acoustic shadow that moves with

gravity. A shadowing effect is present in most instances. Occasionally a similar shadowing

effect may be produced by sound refraction artifacts or pockets of bowel gas (Sommer et al;

Taylor et al, 1979).

In another pattern the gallbladder itself may not be visualized, but a gallstone may be seen

as well as its shadowing effect. In a third pattern the gallstone and gallbladder are not

visualized. In these instances the gallbladder lumen may be obliterated by varying combinations

of calculi and fibrotic scarring. When there is nonvisualization by ultrasonography of either a

gallstone or the gallbladder, the differential diagnosis must include chronic cholecystitis;

gallbladder carcinoma; obstruction of the biliary tree proximal to the cystic duct; and congenital

absence of the gallbladder.

When nonshadowing focal opacities within the gallbladder are recognized, the differential

diagnosis must include cholesterol crystals, polyps, mucin plugs, blood clots, or pus.

A fluid level may at times be demonstrable with sludge or viscous bile, but the likelihood of

discrete calculi in conjunction with this is very small.

Thickening of the gallbladder wall may also be demonstrated by ultrasound, and this has a

high correlation with surgically proven acute and chronic cholecystitis (Sanders). However,

caution must be exercised in the interpretation of gallbladder wall thickness when ascites is

present or when the patient has not been fasting.

A very thin sonolucent pericholecystic fluid accumulation may occur with acute

cholecystitis (Marchal et al). The sensitivity of this particular sign is yet to be proved.

Pericholecystic abscess, carcinoma of the gallbladder, and papilloma of the gallbladder,

which indeed were rarely diagnosed preoperatively (except for the latter), can now be identified

by ultrasound, although their sonographic appearances are often very similar. At times there is a

prominent rimlike halo or mass surrounding the gallbladder with an abscess. At times a mass

may be identified even surrounding the gallbladder. Under these circumstances, when this

represents a gallbladder carcinoma, it may be differentiated from an abscess by the presence of

dilated bile ducts or hepatic metastatic lesions.

With regard to the radionuclide imaging procedures (Harvey et al) 99mtechnetium lidofenin

(99mtechnetium-labeled-dirnethylacetanilide iminodiacetic acid) is now widely employed. It is

particularly advantageous in patients with acute right upper quadrant pain suspected of having

acute cholecystitis. The imaging agent (abbreviated "'"technetium HIDA) is actively taken up by

the liver cells and within one hour is excreted unchanged into the biliary system and bowel.

Normally, liver activity peaks within 5 to 10 minutes; the common bile duct, gallbladder, and

duodenum are usually visualized in 15 to 30 minutes. When the gallbladder is not visualized,

cystic duct obstruction may be postulated. In general, visualization of the gallbladder establishes

patency of the cystic duct and excludes the diagnosis of acute cholecystitis with an accuracy

exceeding 90 per cent and. probably on the order of 95 per cent. Nonvisualization of the

gallbladder with visualization of the common bile duct may then be seen.

When cholescintigraphy, ultrasonography, and contrast cholangiography are compared, it is

probable that cholescintigraphy is the most sensitive to active cholecystitis. Cholangiography

and ultrasound visualize gallstones. However, cholescintigraphy is not specific when the

bilirubin level exceeds 5 mg per dl (Rosenthall et al). Occasionally, nonvisualization by

scintigraphic techniques results from chronic cholecystitis, but generally patients with chronic

right upper quadrant symptoms are more effectively investigated by oral cholecystography and

ultrasound.

Thus, in summary, the complementary nature of oral cholecystography, ultrasonography,

and cholescintigraphy may be emphasized. Although oral cholecystography is still preferred as

the screening technique for detection 9f cholelithiasis, there has been a steady improvement in

ultrasonography for this purpose, and very likely ultrasonography should be used immediately

following oral cholecystography if the former fails to visualize the gallbladder. Unfortunately,

1-mm to 2-mm calculi are not seen by oral cholecystography and yet are routinely displayed by

ultrasonography.

Moreover, in the presence of pregnancy, or a history of allergy to oral cholecystographic

media, suspected acute cholecystitis, hepatic dysfunction, and right upper quadrant pain

syndromes, ultrasonography or cholescintigraphy may well be the initial examinations. Ionizing

radiation is, of course, to be avoided in the presence of pregnancy if possible. Needless to say,

there are disadvantages to the ultrasonographic examination, such as interference by bowel gas

and barium and failure of reflection of the physiological function of the liver.

Empyema of the gallbladder presents a complication in the natural history of acute

cholecystitis (Fry et al). It is believed by Fry and associates that probably approximately 11 per

cent of patients, usually men, undergoing cholecystectomy may be found to have empyema of

the gallbladder. The operative findings may include perforation of the gallbladder and

extrabiliary abscesses. It will be recalled that empyema of the gallbladder gives roentgen

evidence of a halo around the gallbladder by conventional radiography in many instances.