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107
Sonographic Detection of Pneumoperitoneum in Patients with Acute Abdomen
Dong Ho Lee1 Jae Hoon Lim Young Tae Ko Yup Yoon
We describe five patients who presented with an acute abdomen in whom pneumoperitoneum was first detected by sonography. All five subsequently were proved to have a perforated viscus. In all cases, the pneumoperitoneum was seen as an echogenic line with a posterior ring-down or reverberation artifact between the anterior abdominal wall and the anterior surface of the liver. The finding was shown best in the right upper quadrant with the patient in the left lateral decubitus position. The echoes caused by the pneumopentoneum overlapped the echoes of the lung during inspiration, but the echoes were separate during expiration. The probable cause of pneumoperitoneum was determined with sonography in four of the five patients: three had perforation of duodenal ulcer and one had perforation of gastric cancer. The fifth patient had a perforated ileum, which was not evident on the sonogram. Our experience with these patients suggests that the detection of pneumoperitoneum on sonography in patients with an acute abdomen is an important sign of a perforated viscus. AJR
154:107-109,
January
1990
Pneumoperitoneum is best shown radiologically on plain films of the chest and abdomen in erect patients. As little as 1 .0 ml of air can be recognized on these radiographs [1 -4]. However, because sonography may be the initial diagnostic procedure in patients with abdominal symptoms, the detection of pneumoperitoneum on sonography provides important diagnostic information [4]. Moreover, sonography may be useful to determine not only the presence but the cause of the pneumoperitoneum. We describe five patients with acute abdominal symptoms due to a perforated viscus in whom pneumoperitoneum was first detected by sonography. In four of the patients, the sonograms showed the cause of the free air.
Materials
and Methods
Five patients with pneumoperitoneum detected by sonography, seen during a period of 4 years (1 985-1 988), were included in the study. There were four men and one woman, ranging
from 29 to 72 years old. All patients complained of diffuse abdominal pain and had generalized rebound tenderness on physical examination. In all cases, the presence of pneumoperitoneum was confirmed on radiographs made after the sonograms. The causes of pneumoperitoneum, established
at surgery,
included
perforation
of duodenal
ulcer (three
patients),
perforation
of
Received June 1 , 1989; accepted after revision August 18, 1989. 1 All authors: Department of Diagnostic Radiol-
gastric cancer (one patient), and perforation
ogy, Kyung Hoe University Hospital, 1, Hoeki-dong, Dongdaemun-ku, Seoul 130-702, Korea. Address
scanners (Toshiba SAL-55A or SSA-90A, Tokyo). Both linear-array and sector transducers were used to examine these patients. The transducer was placed longitudinally and trans-
reprint
versely on the anterior When pneumoperitoneum space in the left lateral
requests
to D. H. Lee.
0361-803X/90/1 541-0107 C American Roentgen Ray Society
Sonograms
were
obtained
with a 3.5-MHz
of ileum by blunt abdominal transducer
on commercially
trauma (one patient). available
real-time
abdominal wall of the right upper quadrant with the patient supine. was suspected, the patient was reexamined through the intercostal decubitus position.
108
LEE
Results
Downloaded from www.ajronline.org by 205.217.247.60 on 11/05/15 from IP address 205.217.247.60. Copyright ARRS. For personal use only; all rights reserved
In all five patients, the pneumoperitoneum was seen as an echogenic line with a posterior ring-down or reverberation artifact between the anterior abdominal wall and the anterior
surface
of the liver (Fig. 1). In three patients,
neum was detected the patient supine. with
the
patient
pneumoperito-
over the anterior aspect of the liver with In these patients, sonograms obtained
in the
left
lateral
decubitus
position
showed
air over the lateral aspect of the right lobe of the liver. In two patients, pneumoperitoneum was not seen on sonograms made with the patient supine, but was detected only on sonograms made with the patient in the left lateral decubitus position (Fig. 2). In two patients, it was difficult to distinguish pneumoperitoneum from the lung on the sonograms. In these cases, sonograms obtained of the patient during inspiration
Fig. 1.-Transverse right upper abdominal sonogram shows pneumoperitoneum as an echogenic line (arrowheads) between anterior surface of right lobe of liver (open arrows) and anterior abdominal wall with posterior ring-down artifacts (solid arrows).
ET AL.
AJR:154,
January
1990
and expiration were useful. The pneumoperitoneum overlapped the lung during inspiration, but the lung and pneumoperitoneum were separate during expiration (Fig. 3). The causes of pneumoperitoneum were predicted on the basis of the sonograms in four of the five patients. In two patients, the wall of the duodenal bulb was thickened, suggesting the presence of a perforated duodenal ulcer. In the third patient, sonography showed a site of perforation in the anterior wall of the duodenal bulb. In the fourth patient, the wall
of the
gastric
antrum
was
markedly
thickened,
and
a
hepatic and lymph node metastasis was detected, suggesting the presence of gastric cancer. Echogenic foci (air bubbles) were seen floating on ascitic fluid in this patient. In the fifth patient, in whom pneumoperitoneum was due to a perforated ileum caused by blunt abdominal trauma, the cause of the free air was not evident on sonography.
Fig. 2.-Effect
of change in patient’s position on sonographic detection of pneumopentoneum. sonogram made with patient supine shows no pneumopentoneum between anterior abdominal wall and anterior surface of liver. B, Parasagittal sonogram made with patient in left lateral decubitus position shows pneumoperitoneum (arrows) with posterior reverberation artifact. A, Transverse
Fig. 3.-Effect
of inspiration
and expiration
on detection of pneumoperitoneum. A, Sonogram made on inspiration shows pneumoperitoneum (P, open arrows) overlapped
by lung (L, arrowheads). B, Sonogram made on expiration shows lung (L, arrowheads) separated from pneumopentoneum
(P, open arrows).
AJR:154, January 1990
SONOGRAPHY
OF
Downloaded from www.ajronline.org by 205.217.247.60 on 11/05/15 from IP address 205.217.247.60. Copyright ARRS. For personal use only; all rights reserved
Discussion We report five patients who presented with acute abdominal symptoms in whom sonograms showed pneumoperitoneum. The free air was observed as an echogenic line with a posterior ring-down or reverberation artifact. Pneumoperitoneum was best shown with the patient in the left lateral decubitus position. Sonograms made during inspiration and expiration helped to distinguish pneumoperitoneum from the lung. Linear-array transducers may be superior to sector transducers for evaluating patients with pneumoperitoneum because of the broader near-field size and because of superior resolution in the near field where the air usually accumulates. The cause of pneumoperitoneum can be detected in some cases on sonography. In our series, a site of perforation of the duodenal bulb due to an ulcer was found in one patient, duodenal ulcer was suggested on the basis of duodenal wall
PNEUMOPERITONEUM
109
thickening in two patients, nosed in one patient.
and gastric
carcinoma
was
diag-
ACKNOWLEDGMENT The authors the preparation
thank Nan Ok Yeo of this manuscript.
for her secretarial assistance in
REFERENCES 1 . Miller RE, Nelson SW. The roentgenologic of free intraperitoneal
gas:
experimental
demonstration and clinical
of tiny amounts AJR 1971;
studies.
112:574-585 2. Miller RE, Becker GJ, Slabaugh RD. Detection of pneumoperitoneum: optimum body position and respiratory phase. AJR 1980;135:487-490 3. Menuck L, Siemers PT. Pneumoperitoneum: importance of right upper quadrant features. AJR 1976;127:753-756 4. Nirapathpongporn 5, Osatavanichvong K, Udompanich 0, et al. Pneumoperitoneum detected by ultrasound. Radiology 1984;150:831-832
107
Sonographic Detection of Pneumoperitoneum in Patients with Acute Abdomen
Dong Ho Lee1 Jae Hoon Lim Young Tae Ko Yup Yoon
We describe five patients who presented with an acute abdomen in whom pneumoperitoneum was first detected by sonography. All five subsequently were proved to have a perforated viscus. In all cases, the pneumoperitoneum was seen as an echogenic line with a posterior ring-down or reverberation artifact between the anterior abdominal wall and the anterior surface of the liver. The finding was shown best in the right upper quadrant with the patient in the left lateral decubitus position. The echoes caused by the pneumopentoneum overlapped the echoes of the lung during inspiration, but the echoes were separate during expiration. The probable cause of pneumoperitoneum was determined with sonography in four of the five patients: three had perforation of duodenal ulcer and one had perforation of gastric cancer. The fifth patient had a perforated ileum, which was not evident on the sonogram. Our experience with these patients suggests that the detection of pneumoperitoneum on sonography in patients with an acute abdomen is an important sign of a perforated viscus. AJR
154:107-109,
January
1990
Pneumoperitoneum is best shown radiologically on plain films of the chest and abdomen in erect patients. As little as 1 .0 ml of air can be recognized on these radiographs [1 -4]. However, because sonography may be the initial diagnostic procedure in patients with abdominal symptoms, the detection of pneumoperitoneum on sonography provides important diagnostic information [4]. Moreover, sonography may be useful to determine not only the presence but the cause of the pneumoperitoneum. We describe five patients with acute abdominal symptoms due to a perforated viscus in whom pneumoperitoneum was first detected by sonography. In four of the patients, the sonograms showed the cause of the free air.
Materials
and Methods
Five patients with pneumoperitoneum detected by sonography, seen during a period of 4 years (1 985-1 988), were included in the study. There were four men and one woman, ranging
from 29 to 72 years old. All patients complained of diffuse abdominal pain and had generalized rebound tenderness on physical examination. In all cases, the presence of pneumoperitoneum was confirmed on radiographs made after the sonograms. The causes of pneumoperitoneum, established
at surgery,
included
perforation
of duodenal
ulcer (three
patients),
perforation
of
Received June 1 , 1989; accepted after revision August 18, 1989. 1 All authors: Department of Diagnostic Radiol-
gastric cancer (one patient), and perforation
ogy, Kyung Hoe University Hospital, 1, Hoeki-dong, Dongdaemun-ku, Seoul 130-702, Korea. Address
scanners (Toshiba SAL-55A or SSA-90A, Tokyo). Both linear-array and sector transducers were used to examine these patients. The transducer was placed longitudinally and trans-
reprint
versely on the anterior When pneumoperitoneum space in the left lateral
requests
to D. H. Lee.
0361-803X/90/1 541-0107 C American Roentgen Ray Society
Sonograms
were
obtained
with a 3.5-MHz
of ileum by blunt abdominal transducer
on commercially
trauma (one patient). available
real-time
abdominal wall of the right upper quadrant with the patient supine. was suspected, the patient was reexamined through the intercostal decubitus position.
108
LEE
Results
Downloaded from www.ajronline.org by 205.217.247.60 on 11/05/15 from IP address 205.217.247.60. Copyright ARRS. For personal use only; all rights reserved
In all five patients, the pneumoperitoneum was seen as an echogenic line with a posterior ring-down or reverberation artifact between the anterior abdominal wall and the anterior
surface
of the liver (Fig. 1). In three patients,
neum was detected the patient supine. with
the
patient
pneumoperito-
over the anterior aspect of the liver with In these patients, sonograms obtained
in the
left
lateral
decubitus
position
showed
air over the lateral aspect of the right lobe of the liver. In two patients, pneumoperitoneum was not seen on sonograms made with the patient supine, but was detected only on sonograms made with the patient in the left lateral decubitus position (Fig. 2). In two patients, it was difficult to distinguish pneumoperitoneum from the lung on the sonograms. In these cases, sonograms obtained of the patient during inspiration
Fig. 1.-Transverse right upper abdominal sonogram shows pneumoperitoneum as an echogenic line (arrowheads) between anterior surface of right lobe of liver (open arrows) and anterior abdominal wall with posterior ring-down artifacts (solid arrows).
ET AL.
AJR:154,
January
1990
and expiration were useful. The pneumoperitoneum overlapped the lung during inspiration, but the lung and pneumoperitoneum were separate during expiration (Fig. 3). The causes of pneumoperitoneum were predicted on the basis of the sonograms in four of the five patients. In two patients, the wall of the duodenal bulb was thickened, suggesting the presence of a perforated duodenal ulcer. In the third patient, sonography showed a site of perforation in the anterior wall of the duodenal bulb. In the fourth patient, the wall
of the
gastric
antrum
was
markedly
thickened,
and
a
hepatic and lymph node metastasis was detected, suggesting the presence of gastric cancer. Echogenic foci (air bubbles) were seen floating on ascitic fluid in this patient. In the fifth patient, in whom pneumoperitoneum was due to a perforated ileum caused by blunt abdominal trauma, the cause of the free air was not evident on sonography.
Fig. 2.-Effect
of change in patient’s position on sonographic detection of pneumopentoneum. sonogram made with patient supine shows no pneumopentoneum between anterior abdominal wall and anterior surface of liver. B, Parasagittal sonogram made with patient in left lateral decubitus position shows pneumoperitoneum (arrows) with posterior reverberation artifact. A, Transverse
Fig. 3.-Effect
of inspiration
and expiration
on detection of pneumoperitoneum. A, Sonogram made on inspiration shows pneumoperitoneum (P, open arrows) overlapped
by lung (L, arrowheads). B, Sonogram made on expiration shows lung (L, arrowheads) separated from pneumopentoneum
(P, open arrows).
AJR:154, January 1990
SONOGRAPHY
OF
Downloaded from www.ajronline.org by 205.217.247.60 on 11/05/15 from IP address 205.217.247.60. Copyright ARRS. For personal use only; all rights reserved
Discussion We report five patients who presented with acute abdominal symptoms in whom sonograms showed pneumoperitoneum. The free air was observed as an echogenic line with a posterior ring-down or reverberation artifact. Pneumoperitoneum was best shown with the patient in the left lateral decubitus position. Sonograms made during inspiration and expiration helped to distinguish pneumoperitoneum from the lung. Linear-array transducers may be superior to sector transducers for evaluating patients with pneumoperitoneum because of the broader near-field size and because of superior resolution in the near field where the air usually accumulates. The cause of pneumoperitoneum can be detected in some cases on sonography. In our series, a site of perforation of the duodenal bulb due to an ulcer was found in one patient, duodenal ulcer was suggested on the basis of duodenal wall
PNEUMOPERITONEUM
109
thickening in two patients, nosed in one patient.
and gastric
carcinoma
was
diag-
ACKNOWLEDGMENT The authors the preparation
thank Nan Ok Yeo of this manuscript.
for her secretarial assistance in
REFERENCES 1 . Miller RE, Nelson SW. The roentgenologic of free intraperitoneal
gas:
experimental
demonstration and clinical
of tiny amounts AJR 1971;
studies.
112:574-585 2. Miller RE, Becker GJ, Slabaugh RD. Detection of pneumoperitoneum: optimum body position and respiratory phase. AJR 1980;135:487-490 3. Menuck L, Siemers PT. Pneumoperitoneum: importance of right upper quadrant features. AJR 1976;127:753-756 4. Nirapathpongporn 5, Osatavanichvong K, Udompanich 0, et al. Pneumoperitoneum detected by ultrasound. Radiology 1984;150:831-832
