Ultrasound
Ultrasound Evaluation of the Gallbladder Wall 1 Harris J. Finberg, M.D., and Jason C. Birnholz, M.D.
In a series of 526 consecutive, unprepared patients examined by ultrasound, the gallbladder was visualized in 507 (96 %). The average wall thickness was 2 mm or less in 97 % of asymptomatic subjects without cholelithiasis and 3 mm or greater in 45 %' of those with cholelithiasis. Pathologic correlation of increased thickness and chronic cholecystitis was made in a subgroup of 47 surgical patients. Local tenderness and mucosal thickening were found in 8 patients with acute cholecystitis. Use of electronic sector scanning is emphasized. INDEX TERMS:
Abdomen, ultrasound studies. 7[0 ].1298. Gallbladder, diseases. Gallbladder, ultrasound studies,
7(62) .1298 Radiology 133:693-698, December 1979
reports have established a clinical role for ultrasonic cholecystography in the diagnosis of cholelithiasis (1,2,4,6, 7, 13) but the common conditions of acute and chronic inflammatory disease have not been treated with equal thoroughness. Gallbladder wall features are an essential part of the pathologic assessment of this organ. Ultrasound visualization of the wall has been reported (5, 9, 11-13) but without systematic quantitation of wall thickness or definite conclusion as to the diagnostic usefulness of ultrasound wall appearance in clinical practice. In this study, a technique for evaluating the gallbladder ultrasonically with electronic sector scanning is presented as prefatory (but integral) to the assessment of both wall thickness and inspection of intraluminal contents in the clinical context. UMEROUS
N
Fig. 1. Measurement of the gallbladder wall (arrows) is made along the axis of the ultrasound beam using the portion of the gallbladder contiguous with the liver and including all identifiable layers. Note the distinguishable , less echodense zone adjacent to the lumen.
METHODS
The study population consists of 526 consecutive patients, without cholecystectomy, referred for abdominal examination for a variety of indications. Specific examination of the right upper quadrant was requested in 29 % because of pain syndromes or food intolerance , believed indicative of intrinsic gallbladder disease. No preparation or food intake restriction was required for any subject initially . Single study findings were accepted for analysis in subjects with multiple examinations. In those cases in which the gallbladder could not be identified, or in which it was markedly contracted , a repeat examination after fasting was requested. Fatty meals were not used. All subjects were examined initially in the supine position by a physician using a commercial electronic sector scanning ultrasound imaging system (Varian 3000) with the following performance features: 30/sec. frame rate, 85° sector 21-cm depth field of view, image line density in excess of 1 line per degree arc, broadband 2.25 MHz center frequency, and fixed-focus cylindrical lens design with 1mm axial and 3.5mm lateral resolution at the 7-10 cm focal depth.
The gallbladder is sought via an intercostal, transhepatic portal, with continuous viewing as the right upper quadrant is examined. Gallbladder visualization is accepted as satisfactory when the central fluid space andthe boundary rim are both defined. While maintaining visualization, overall receiver gain and transmitter output are minimized for suppression of acoustic artefacts. Long and short axis views of the gallbladder are achieved by probe rotation and the entire volume of the gallbladder reviewed in each projection . Additional viewing with the subject in left decubitus or upright positions is at the discretion of the examiner as are ancillary static images with a manual scan device (Searle Phosonic) with transducer selection predicated upon minimal beam width at the depth of the gallbladder. In patients with right upper quadrant pain, the probe is placed in the subcostal location most proximate to the gallbladder, and observation is continued during deep probe palpation and deep inspiratory effort (3). A positive
1 From the Department of Radiology, Harvard Medical School, and Peter Bent Brigham Hospital, Boston, MA 02115. Presentedat the Sixty-fourth Scientific Assembly and Annual Meeting of the Radiological Society of North America, Chicago. IL, Nov. 26-Dec. 1. 1978. Submitted for publication 21 Nov. 1978; rev ision requested 13 April 1979: received 25 July and accepted 24 Aug. 1979. shan
693
HARRIS J. FINBERG AND JASON
694
C.
BIRNHOLZ
December 1979
2 a, b
2
C,
d
Fig. 2. Variations in gallbladder wall thickness in 4 patients with chole lithias is. The scale in each is the same. Pathologic diagnoses are listed: a: 1-2 mm, chronic cholecystitis; b: 3 mm, chronic cholecystitis; c: 5 mm , chronic cholecystitis with marked serosal fibrosis ; d: 8 mm, acute and chron ic cholecy stitis.
Murphy sign is recorded when pain is elicited only during image-verified deformation of the gallbladder. A general survey of the upper abdomen is also performed in all patients. Particular attention is directed to the biliary duct system. hepatic parenchyma and pancreas , but the spleen, kidneys, midabdominal vascular structures and pleural and peritoneal spaces are also reviewed. The gallbladder wall is defined as the discrete echodense margin encircling the fluid-filled lumen. It is important to note whether a relatively hypoechoic rim is identified adjacent to the luminal surface apposed to the echodense zone. The entire thickness of the nearer, subhepatic wall is measured from static Polaroid images when the ultrasound beam is perpendicular to the wall (Fig. 1). Wall
thickness measurements from all images available for each examination are averaged and rounded to the nearest millimeter. Calculi are diagnosed when discrete, echodense intraluminal bodies are seen and when these cast acoustic shadows when scanned with an extrapolated beam width, which at that depth, is no greater than the dimension of these bodies. Layered, dependent, uniform echodense intraluminal material without shadowing is considered " dense" bile and is recorded separately . Direct measurement of wall thickness is made with calipers in surgical specimens prior to fixation or refrigeration . These measurements are also recorded to the nearest millimeter.
ULTRASOUND EVALUATION OF THE GALLBLADDER WALL
Vol. 133
TABlE I:
Chronic
Chronic Active
1-2 3
15 3
0
4
6 3
Ultrasound
PATHOLOGIC FINDINGS IN 40 PATIENTS TyPE OF CHOLECYSTITIS
Ultrasound Wall (mm)
~5
695
Chronic and Acute
Subacute
Acute
3
a
a 1 a
1 1
a
a
0 1
1
a
4
1
1-2 different from ~ 5 at p
Ultrasound Evaluation of the Gallbladder Wall 1 Harris J. Finberg, M.D., and Jason C. Birnholz, M.D.
In a series of 526 consecutive, unprepared patients examined by ultrasound, the gallbladder was visualized in 507 (96 %). The average wall thickness was 2 mm or less in 97 % of asymptomatic subjects without cholelithiasis and 3 mm or greater in 45 %' of those with cholelithiasis. Pathologic correlation of increased thickness and chronic cholecystitis was made in a subgroup of 47 surgical patients. Local tenderness and mucosal thickening were found in 8 patients with acute cholecystitis. Use of electronic sector scanning is emphasized. INDEX TERMS:
Abdomen, ultrasound studies. 7[0 ].1298. Gallbladder, diseases. Gallbladder, ultrasound studies,
7(62) .1298 Radiology 133:693-698, December 1979
reports have established a clinical role for ultrasonic cholecystography in the diagnosis of cholelithiasis (1,2,4,6, 7, 13) but the common conditions of acute and chronic inflammatory disease have not been treated with equal thoroughness. Gallbladder wall features are an essential part of the pathologic assessment of this organ. Ultrasound visualization of the wall has been reported (5, 9, 11-13) but without systematic quantitation of wall thickness or definite conclusion as to the diagnostic usefulness of ultrasound wall appearance in clinical practice. In this study, a technique for evaluating the gallbladder ultrasonically with electronic sector scanning is presented as prefatory (but integral) to the assessment of both wall thickness and inspection of intraluminal contents in the clinical context. UMEROUS
N
Fig. 1. Measurement of the gallbladder wall (arrows) is made along the axis of the ultrasound beam using the portion of the gallbladder contiguous with the liver and including all identifiable layers. Note the distinguishable , less echodense zone adjacent to the lumen.
METHODS
The study population consists of 526 consecutive patients, without cholecystectomy, referred for abdominal examination for a variety of indications. Specific examination of the right upper quadrant was requested in 29 % because of pain syndromes or food intolerance , believed indicative of intrinsic gallbladder disease. No preparation or food intake restriction was required for any subject initially . Single study findings were accepted for analysis in subjects with multiple examinations. In those cases in which the gallbladder could not be identified, or in which it was markedly contracted , a repeat examination after fasting was requested. Fatty meals were not used. All subjects were examined initially in the supine position by a physician using a commercial electronic sector scanning ultrasound imaging system (Varian 3000) with the following performance features: 30/sec. frame rate, 85° sector 21-cm depth field of view, image line density in excess of 1 line per degree arc, broadband 2.25 MHz center frequency, and fixed-focus cylindrical lens design with 1mm axial and 3.5mm lateral resolution at the 7-10 cm focal depth.
The gallbladder is sought via an intercostal, transhepatic portal, with continuous viewing as the right upper quadrant is examined. Gallbladder visualization is accepted as satisfactory when the central fluid space andthe boundary rim are both defined. While maintaining visualization, overall receiver gain and transmitter output are minimized for suppression of acoustic artefacts. Long and short axis views of the gallbladder are achieved by probe rotation and the entire volume of the gallbladder reviewed in each projection . Additional viewing with the subject in left decubitus or upright positions is at the discretion of the examiner as are ancillary static images with a manual scan device (Searle Phosonic) with transducer selection predicated upon minimal beam width at the depth of the gallbladder. In patients with right upper quadrant pain, the probe is placed in the subcostal location most proximate to the gallbladder, and observation is continued during deep probe palpation and deep inspiratory effort (3). A positive
1 From the Department of Radiology, Harvard Medical School, and Peter Bent Brigham Hospital, Boston, MA 02115. Presentedat the Sixty-fourth Scientific Assembly and Annual Meeting of the Radiological Society of North America, Chicago. IL, Nov. 26-Dec. 1. 1978. Submitted for publication 21 Nov. 1978; rev ision requested 13 April 1979: received 25 July and accepted 24 Aug. 1979. shan
693
HARRIS J. FINBERG AND JASON
694
C.
BIRNHOLZ
December 1979
2 a, b
2
C,
d
Fig. 2. Variations in gallbladder wall thickness in 4 patients with chole lithias is. The scale in each is the same. Pathologic diagnoses are listed: a: 1-2 mm, chronic cholecystitis; b: 3 mm, chronic cholecystitis; c: 5 mm , chronic cholecystitis with marked serosal fibrosis ; d: 8 mm, acute and chron ic cholecy stitis.
Murphy sign is recorded when pain is elicited only during image-verified deformation of the gallbladder. A general survey of the upper abdomen is also performed in all patients. Particular attention is directed to the biliary duct system. hepatic parenchyma and pancreas , but the spleen, kidneys, midabdominal vascular structures and pleural and peritoneal spaces are also reviewed. The gallbladder wall is defined as the discrete echodense margin encircling the fluid-filled lumen. It is important to note whether a relatively hypoechoic rim is identified adjacent to the luminal surface apposed to the echodense zone. The entire thickness of the nearer, subhepatic wall is measured from static Polaroid images when the ultrasound beam is perpendicular to the wall (Fig. 1). Wall
thickness measurements from all images available for each examination are averaged and rounded to the nearest millimeter. Calculi are diagnosed when discrete, echodense intraluminal bodies are seen and when these cast acoustic shadows when scanned with an extrapolated beam width, which at that depth, is no greater than the dimension of these bodies. Layered, dependent, uniform echodense intraluminal material without shadowing is considered " dense" bile and is recorded separately . Direct measurement of wall thickness is made with calipers in surgical specimens prior to fixation or refrigeration . These measurements are also recorded to the nearest millimeter.
ULTRASOUND EVALUATION OF THE GALLBLADDER WALL
Vol. 133
TABlE I:
Chronic
Chronic Active
1-2 3
15 3
0
4
6 3
Ultrasound
PATHOLOGIC FINDINGS IN 40 PATIENTS TyPE OF CHOLECYSTITIS
Ultrasound Wall (mm)
~5
695
Chronic and Acute
Subacute
Acute
3
a
a 1 a
1 1
a
a
0 1
1
a
4
1
1-2 different from ~ 5 at p
