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Emphysematous Infections of the Abdomen and Pelvis: A Pictorial Review¹

¹ From the Department of Radiology, Wilford Hall Medical Center, 759th MDTS/MTRD, 2200 Bergquist Dr, Suite 1, Lackland AFB, TX 78236-5300 (D.E.G., R.M.A., P.M.S.); the Department of Radiology, University of Texas Health Science Center, San Antonio (R.M.A.); the Department of Radiologic Pathology, Armed Forces Institute of Pathology, Washington, DC (A.D.L); and the Department of Radiology and Nuclear Medicine, Uniformed Services University of the Health Sciences, Bethesda, Md (A.D.L.). Presented as an education exhibit at the 2000 RSNA scientific assembly. Received August 7, 2001; revision requested October 8 and received November 7; accepted November 7. Address correspondence to D.E.G. (e-mail: dgrayson@satx.rr.com).

View larger version (157K): [in a new window]   Figure 1a.  Stage 2 emphysematous cholecystitis. (a) Abdominal radiograph obtained in a 78-year-old diabetic man demonstrates gas within the gallbladder wall (arrows). (b) Photograph of the cut gross specimen shows areas of transmural infarction (arrows) and hemorrhagic necrosis (*). (c) Radiograph obtained in a different patient shows intramural gas that delineates the characteristic gallbladder shape (arrowheads). (d) Photomicrograph reveals diffuse edema, foci of hemorrhage (short arrows), and multiple cystic gas collections (long arrows) in the gallbladder wall.

View larger version (141K): [in a new window]   Figure 1b.  Stage 2 emphysematous cholecystitis. (a) Abdominal radiograph obtained in a 78-year-old diabetic man demonstrates gas within the gallbladder wall (arrows). (b) Photograph of the cut gross specimen shows areas of transmural infarction (arrows) and hemorrhagic necrosis (*). (c) Radiograph obtained in a different patient shows intramural gas that delineates the characteristic gallbladder shape (arrowheads). (d) Photomicrograph reveals diffuse edema, foci of hemorrhage (short arrows), and multiple cystic gas collections (long arrows) in the gallbladder wall.

View larger version (129K): [in a new window]   Figure 1c.  Stage 2 emphysematous cholecystitis. (a) Abdominal radiograph obtained in a 78-year-old diabetic man demonstrates gas within the gallbladder wall (arrows). (b) Photograph of the cut gross specimen shows areas of transmural infarction (arrows) and hemorrhagic necrosis (*). (c) Radiograph obtained in a different patient shows intramural gas that delineates the characteristic gallbladder shape (arrowheads). (d) Photomicrograph reveals diffuse edema, foci of hemorrhage (short arrows), and multiple cystic gas collections (long arrows) in the gallbladder wall.

View larger version (188K): [in a new window]   Figure 1d.  Stage 2 emphysematous cholecystitis. (a) Abdominal radiograph obtained in a 78-year-old diabetic man demonstrates gas within the gallbladder wall (arrows). (b) Photograph of the cut gross specimen shows areas of transmural infarction (arrows) and hemorrhagic necrosis (*). (c) Radiograph obtained in a different patient shows intramural gas that delineates the characteristic gallbladder shape (arrowheads). (d) Photomicrograph reveals diffuse edema, foci of hemorrhage (short arrows), and multiple cystic gas collections (long arrows) in the gallbladder wall.

View larger version (170K): [in a new window]   Figure 2a.  Hepatic abscess in an intensive care patient with fever and abdominal pain. (a) Digital scout image from an abdominal computed tomographic (CT) scan shows a well-defined collection of mottled gas overlying the right upper quadrant (arrows). (b) Unenhanced axial CT scan obtained at the same level reveals air within a pyogenic hepatic abscess (arrows).

View larger version (176K): [in a new window]   Figure 2b.  Hepatic abscess in an intensive care patient with fever and abdominal pain. (a) Digital scout image from an abdominal computed tomographic (CT) scan shows a well-defined collection of mottled gas overlying the right upper quadrant (arrows). (b) Unenhanced axial CT scan obtained at the same level reveals air within a pyogenic hepatic abscess (arrows).

View larger version (169K): [in a new window]   Figure 3a.  Emphysematous cholecystitis in a 49-year-old diabetic man with a 2-day history of substernal pain and fever. (a) Transverse US image through the gallbladder fossa demonstrates a curvilinear collection of high-amplitude echoes (arrowheads) with posterior dirty shadowing (arrow). (b) Longitudinal US image shows a diffusely echogenic gallbladder wall secondary to intramural gas (arrowheads). (c) US image reveals multiple tiny echogenic reflectors within the gallbladder lumen (arrows) corresponding to gas bubbles arising from the dependent wall (champagne sign).

View larger version (188K): [in a new window]   Figure 3b.  Emphysematous cholecystitis in a 49-year-old diabetic man with a 2-day history of substernal pain and fever. (a) Transverse US image through the gallbladder fossa demonstrates a curvilinear collection of high-amplitude echoes (arrowheads) with posterior dirty shadowing (arrow). (b) Longitudinal US image shows a diffusely echogenic gallbladder wall secondary to intramural gas (arrowheads). (c) US image reveals multiple tiny echogenic reflectors within the gallbladder lumen (arrows) corresponding to gas bubbles arising from the dependent wall (champagne sign).

View larger version (185K): [in a new window]   Figure 3c.  Emphysematous cholecystitis in a 49-year-old diabetic man with a 2-day history of substernal pain and fever. (a) Transverse US image through the gallbladder fossa demonstrates a curvilinear collection of high-amplitude echoes (arrowheads) with posterior dirty shadowing (arrow). (b) Longitudinal US image shows a diffusely echogenic gallbladder wall secondary to intramural gas (arrowheads). (c) US image reveals multiple tiny echogenic reflectors within the gallbladder lumen (arrows) corresponding to gas bubbles arising from the dependent wall (champagne sign).

View larger version (151K): [in a new window]   Figure 4a.  Emphysematous cholecystitis. (a) Unenhanced CT scan through the upper abdomen demonstrates predominantly intramural gas collections (arrows). (b) Unenhanced CT scan obtained in a different patient clearly shows intramural (white arrows) and intraluminal (*) gas. A right renal cyst is incidentally seen (black arrow).

View larger version (157K): [in a new window]   Figure 4b.  Emphysematous cholecystitis. (a) Unenhanced CT scan through the upper abdomen demonstrates predominantly intramural gas collections (arrows). (b) Unenhanced CT scan obtained in a different patient clearly shows intramural (white arrows) and intraluminal (*) gas. A right renal cyst is incidentally seen (black arrow).

View larger version (168K): [in a new window]   Figure 5a.  Emphysematous cholecystitis. (a) Contrast material-enhanced CT scan through the upper abdomen demonstrates gas within the gallbladder wall (black arrows) and lumen (*) and cholelithiasis (white arrow). (b) CT scan obtained cephalad to a shows an area of air attenuation centrally within the liver (white arrow) secondary to associated pneumobilia. A feeding tube is seen within the duodenum (black arrow). (c) Photograph of the gross specimen reveals evidence of perforation within a large area of transmural necrosis (arrows).

View larger version (155K): [in a new window]   Figure 5b.  Emphysematous cholecystitis. (a) Contrast material-enhanced CT scan through the upper abdomen demonstrates gas within the gallbladder wall (black arrows) and lumen (*) and cholelithiasis (white arrow). (b) CT scan obtained cephalad to a shows an area of air attenuation centrally within the liver (white arrow) secondary to associated pneumobilia. A feeding tube is seen within the duodenum (black arrow). (c) Photograph of the gross specimen reveals evidence of perforation within a large area of transmural necrosis (arrows).

View larger version (130K): [in a new window]   Figure 5c.  Emphysematous cholecystitis. (a) Contrast material-enhanced CT scan through the upper abdomen demonstrates gas within the gallbladder wall (black arrows) and lumen (*) and cholelithiasis (white arrow). (b) CT scan obtained cephalad to a shows an area of air attenuation centrally within the liver (white arrow) secondary to associated pneumobilia. A feeding tube is seen within the duodenum (black arrow). (c) Photograph of the gross specimen reveals evidence of perforation within a large area of transmural necrosis (arrows).

View larger version (116K): [in a new window]   Figures 6.  Emphysematous cholecystitis in a 49-year-old man with diffuse abdominal pain. Anterior scintigram from a hepatobiliary study shows a region of increased hepatic activity (arrows) adjacent to the relatively photopenic gallbladder fossa (g) (rim sign). The gallbladder itself is not visualized. Normal bowel activity is present (b). (Fig 6 courtesy of Yong Bradley, MD, Brook Army Medical Center, San Antonio, Texas.)

View larger version (184K): [in a new window]   Figure 7a.  Emphysematous gastritis in a 33-year-old man with a history of ethanol abuse. (a) Abdominal radiograph obtained with the patient upright shows mottled and irregular collections of gas within the stomach wall (arrows). An endogastric tube and abdominal surgical clips are also seen. (b) Contrast-enhanced CT scan through the upper abdomen clearly demonstrates a massive collection of intramural gas (white arrows). Enteric contrast material defines the gastric lumen (*). Periportal edema is also seen (black arrows). (c) Photograph of the gross specimen reveals diffuse hemorrhagic necrosis (arrows) and thickened mucosal folds. A large number of gram-positive cocci were seen at histologic analysis.

View larger version (160K): [in a new window]   Figure 7b.  Emphysematous gastritis in a 33-year-old man with a history of ethanol abuse. (a) Abdominal radiograph obtained with the patient upright shows mottled and irregular collections of gas within the stomach wall (arrows). An endogastric tube and abdominal surgical clips are also seen. (b) Contrast-enhanced CT scan through the upper abdomen clearly demonstrates a massive collection of intramural gas (white arrows). Enteric contrast material defines the gastric lumen (*). Periportal edema is also seen (black arrows). (c) Photograph of the gross specimen reveals diffuse hemorrhagic necrosis (arrows) and thickened mucosal folds. A large number of gram-positive cocci were seen at histologic analysis.

View larger version (169K): [in a new window]   Figure 7c.  Emphysematous gastritis in a 33-year-old man with a history of ethanol abuse. (a) Abdominal radiograph obtained with the patient upright shows mottled and irregular collections of gas within the stomach wall (arrows). An endogastric tube and abdominal surgical clips are also seen. (b) Contrast-enhanced CT scan through the upper abdomen clearly demonstrates a massive collection of intramural gas (white arrows). Enteric contrast material defines the gastric lumen (*). Periportal edema is also seen (black arrows). (c) Photograph of the gross specimen reveals diffuse hemorrhagic necrosis (arrows) and thickened mucosal folds. A large number of gram-positive cocci were seen at histologic analysis.

View larger version (150K): [in a new window]   Figure 8a.  Emphysematous gastritis in a 69-year-old woman who presented with hypovolemia and metabolic acidosis. (a) Unenhanced CT scan through the upper abdomen shows nodular and irregular collections of gas within the stomach wall (black arrows). The presence of enteric contrast material aids in their visualization. Branching collections of gas extend peripherally within the liver (white arrows) in a pattern characteristic of portal venous air. (b) Photograph of the gross specimen shows a large area of necrosis involving the serosal surface of the posterior stomach wall (arrows). Large numbers of submucosal gas bubbles were present at the time of pathologic examination.

View larger version (99K): [in a new window]   Figure 8b.  Emphysematous gastritis in a 69-year-old woman who presented with hypovolemia and metabolic acidosis. (a) Unenhanced CT scan through the upper abdomen shows nodular and irregular collections of gas within the stomach wall (black arrows). The presence of enteric contrast material aids in their visualization. Branching collections of gas extend peripherally within the liver (white arrows) in a pattern characteristic of portal venous air. (b) Photograph of the gross specimen shows a large area of necrosis involving the serosal surface of the posterior stomach wall (arrows). Large numbers of submucosal gas bubbles were present at the time of pathologic examination.

View larger version (163K): [in a new window]   Figure 9a.  Benign gastric emphysema in an asymptomatic 68-year-old man undergoing high-dose dexamethasone therapy. (a) Abdominal radiograph obtained with the patient upright demonstrates a thin, linear area of increased radiolucency that outlines the gastric wall (arrows). (b) Unenhanced CT scan obtained at the same level helps confirm the presence of a thin, linear distribution of intramural air (arrows). Compare this finding with the nodular appearance of emphysematous gastritis in Figure 8a.

View larger version (147K): [in a new window]   Figure 9b.  Benign gastric emphysema in an asymptomatic 68-year-old man undergoing high-dose dexamethasone therapy. (a) Abdominal radiograph obtained with the patient upright demonstrates a thin, linear area of increased radiolucency that outlines the gastric wall (arrows). (b) Unenhanced CT scan obtained at the same level helps confirm the presence of a thin, linear distribution of intramural air (arrows). Compare this finding with the nodular appearance of emphysematous gastritis in Figure 8a.

View larger version (187K): [in a new window]   Figure 10a.  Emphysematous pancreatitis in a 68-year-old woman. (a) Digital scout image from a CT scan demonstrates a mottled collection of gas bubbles in the midportion of the upper abdomen and extending into the left upper quadrant. (b, c) Contrast-enhanced CT scans obtained at the same level as a show gas surrounding the body and tail of the pancreas (arrows in b) and extending more cephalad within the anterior pararenal space (c). There are extensive inflammatory changes involving the surrounding fat (arrows in c).

View larger version (183K): [in a new window]   Figure 10b.  Emphysematous pancreatitis in a 68-year-old woman. (a) Digital scout image from a CT scan demonstrates a mottled collection of gas bubbles in the midportion of the upper abdomen and extending into the left upper quadrant. (b, c) Contrast-enhanced CT scans obtained at the same level as a show gas surrounding the body and tail of the pancreas (arrows in b) and extending more cephalad within the anterior pararenal space (c). There are extensive inflammatory changes involving the surrounding fat (arrows in c).

View larger version (177K): [in a new window]   Figure 10c.  Emphysematous pancreatitis in a 68-year-old woman. (a) Digital scout image from a CT scan demonstrates a mottled collection of gas bubbles in the midportion of the upper abdomen and extending into the left upper quadrant. (b, c) Contrast-enhanced CT scans obtained at the same level as a show gas surrounding the body and tail of the pancreas (arrows in b) and extending more cephalad within the anterior pararenal space (c). There are extensive inflammatory changes involving the surrounding fat (arrows in c).

View larger version (155K): [in a new window]   Figure 11.  Bilateral emphysematous pyelonephritis in a 72-year-old man who presented with fever, chills, and near syncope. Abdominal radiograph reveals extensive, radially oriented air within and surrounding the kidneys (black arrows). Air is also seen within the left renal collecting system (white arrows).

View larger version (196K): [in a new window]   Figure 12a.  Emphysematous pyelonephritis in a 45-year-old woman. (a) Abdominal radiograph obtained with the patient upright demonstrates a 2-cm calcification overlying the region of the left ureteropelvic junction (arrow) and several smaller calcifications overlying the lower pole. Note also the mottled collection of gas bubbles in the region of the left lower renal pole (arrowheads) and the large air-fluid level within the upper pole (*). (b) Contrast-enhanced excretory-phase CT scan obtained at the same level as a demonstrates enlargement of the left kidney with persistent parenchymal enhancement relative to the normal right kidney. Note the air-fluid and debris level (*) within the upper pole, a finding that corresponds to the radiographic finding. A large obstructing ureteral stone (arrow) and perinephric inflammatory changes are also present. (c) Photograph of the cut gross specimen reveals diffuse parenchymal necrosis.

View larger version (158K): [in a new window]   Figure 12b.  Emphysematous pyelonephritis in a 45-year-old woman. (a) Abdominal radiograph obtained with the patient upright demonstrates a 2-cm calcification overlying the region of the left ureteropelvic junction (arrow) and several smaller calcifications overlying the lower pole. Note also the mottled collection of gas bubbles in the region of the left lower renal pole (arrowheads) and the large air-fluid level within the upper pole (*). (b) Contrast-enhanced excretory-phase CT scan obtained at the same level as a demonstrates enlargement of the left kidney with persistent parenchymal enhancement relative to the normal right kidney. Note the air-fluid and debris level (*) within the upper pole, a finding that corresponds to the radiographic finding. A large obstructing ureteral stone (arrow) and perinephric inflammatory changes are also present. (c) Photograph of the cut gross specimen reveals diffuse parenchymal necrosis.

View larger version (148K): [in a new window]   Figure 12c.  Emphysematous pyelonephritis in a 45-year-old woman. (a) Abdominal radiograph obtained with the patient upright demonstrates a 2-cm calcification overlying the region of the left ureteropelvic junction (arrow) and several smaller calcifications overlying the lower pole. Note also the mottled collection of gas bubbles in the region of the left lower renal pole (arrowheads) and the large air-fluid level within the upper pole (*). (b) Contrast-enhanced excretory-phase CT scan obtained at the same level as a demonstrates enlargement of the left kidney with persistent parenchymal enhancement relative to the normal right kidney. Note the air-fluid and debris level (*) within the upper pole, a finding that corresponds to the radiographic finding. A large obstructing ureteral stone (arrow) and perinephric inflammatory changes are also present. (c) Photograph of the cut gross specimen reveals diffuse parenchymal necrosis.

View larger version (151K): [in a new window]   Figure 13a.  Emphysematous pyelonephritis in a 49-year-old diabetic woman. (a) Longitudinal US image of the left kidney demonstrates multiple hyperechoic foci (long arrows) with dirty acoustic shadowing (short arrow), a finding that represents gas within the renal parenchyma. (b) Photograph of the cut gross specimen reveals numerous parenchymal abscesses filled with yellow-tan purulent exudate (arrows).

View larger version (135K): [in a new window]   Figure 13b.  Emphysematous pyelonephritis in a 49-year-old diabetic woman. (a) Longitudinal US image of the left kidney demonstrates multiple hyperechoic foci (long arrows) with dirty acoustic shadowing (short arrow), a finding that represents gas within the renal parenchyma. (b) Photograph of the cut gross specimen reveals numerous parenchymal abscesses filled with yellow-tan purulent exudate (arrows).

View larger version (150K): [in a new window]   Figure 14a.  Emphysematous pyelonephritis. (a) Transverse US image through the middle of the left kidney shows high-amplitude echoes (long arrow) representing air along the nondependent aspect of a parenchymal fluid collection (*). The more posteriorly located perinephric air has a similar appearance (short arrows). (b) Contrast-enhanced CT scan (enteric contrast material) clearly depicts air within the kidney (*) and perinephric space (arrow).

View larger version (180K): [in a new window]   Figure 14b.  Emphysematous pyelonephritis. (a) Transverse US image through the middle of the left kidney shows high-amplitude echoes (long arrow) representing air along the nondependent aspect of a parenchymal fluid collection (*). The more posteriorly located perinephric air has a similar appearance (short arrows). (b) Contrast-enhanced CT scan (enteric contrast material) clearly depicts air within the kidney (*) and perinephric space (arrow).

View larger version (161K): [in a new window]   Figure 15a.  Emphysematous pyelonephritis in a 60-year-old diabetic man with several days’ history of nausea and general malaise. (a) Longitudinal US image of the left kidney demonstrates normal findings. (b) Longitudinal US image of the right kidney shows foci of high-amplitude echoes (long arrow) with associated posterior dirty shadowing (short arrow). (c) Corresponding contrast-enhanced CT scan obtained during the late excretory phase shows multiple parenchymal gas collections (arrows). Earlier-phase images (not shown) demonstrated decreased perfusion and excretion relative to the normal left kidney.

View larger version (180K): [in a new window]   Figure 15b.  Emphysematous pyelonephritis in a 60-year-old diabetic man with several days’ history of nausea and general malaise. (a) Longitudinal US image of the left kidney demonstrates normal findings. (b) Longitudinal US image of the right kidney shows foci of high-amplitude echoes (long arrow) with associated posterior dirty shadowing (short arrow). (c) Corresponding contrast-enhanced CT scan obtained during the late excretory phase shows multiple parenchymal gas collections (arrows). Earlier-phase images (not shown) demonstrated decreased perfusion and excretion relative to the normal left kidney.

View larger version (172K): [in a new window]   Figure 15c.  Emphysematous pyelonephritis in a 60-year-old diabetic man with several days’ history of nausea and general malaise. (a) Longitudinal US image of the left kidney demonstrates normal findings. (b) Longitudinal US image of the right kidney shows foci of high-amplitude echoes (long arrow) with associated posterior dirty shadowing (short arrow). (c) Corresponding contrast-enhanced CT scan obtained during the late excretory phase shows multiple parenchymal gas collections (arrows). Earlier-phase images (not shown) demonstrated decreased perfusion and excretion relative to the normal left kidney.

View larger version (164K): [in a new window]   Figure 16a.  Emphysematous pyelonephritis. (a) Type I emphysematous pyelonephritis. Contrast-enhanced CT scan demonstrates gas that radiates diffusely throughout the renal parenchyma (arrow). No associated fluid collections are seen. (b) Type II emphysematous pyelonephritis. CT scan obtained in a different patient shows several small foci of gas, some with associated regions of fluid attenuation (black arrows). These fluid-attenuation regions are thought to represent a more favorable immune response. Vicarious excretion of contrast material is also seen within the gallbladder (white arrow).

View larger version (161K): [in a new window]   Figure 16b.  Emphysematous pyelonephritis. (a) Type I emphysematous pyelonephritis. Contrast-enhanced CT scan demonstrates gas that radiates diffusely throughout the renal parenchyma (arrow). No associated fluid collections are seen. (b) Type II emphysematous pyelonephritis. CT scan obtained in a different patient shows several small foci of gas, some with associated regions of fluid attenuation (black arrows). These fluid-attenuation regions are thought to represent a more favorable immune response. Vicarious excretion of contrast material is also seen within the gallbladder (white arrow).

View larger version (173K): [in a new window]   Figure 17a.  Emphysematous pyelitis. (a) Abdominal radiograph obtained during the excretory phase of an intravenous urogram with the patient supine demonstrates multiple air bubbles within the renal collecting systems (arrows) and moderate hydronephrosis bilaterally. (b) Delayed tomographic image localized over the distal left ureter demonstrates multiple tiny intramural gas bubbles and a dilated left ureter (arrows).

View larger version (185K): [in a new window]   Figure 17b.  Emphysematous pyelitis. (a) Abdominal radiograph obtained during the excretory phase of an intravenous urogram with the patient supine demonstrates multiple air bubbles within the renal collecting systems (arrows) and moderate hydronephrosis bilaterally. (b) Delayed tomographic image localized over the distal left ureter demonstrates multiple tiny intramural gas bubbles and a dilated left ureter (arrows).

View larger version (176K): [in a new window]   Figure 18.  Complicated emphysematous pyelitis. Contrast-enhanced CT scan obtained at the level of the kidneys shows air within the left renal pelvis (white arrow) and anterior calix. Focal parenchymal (arrowheads) and perinephric (black arrows) fluid collections are also well demonstrated.

View larger version (134K): [in a new window]   Figure 19a.  Emphysematous cystitis. (a) Pelvic radiograph obtained with the patient upright demonstrates circumlinear streaks of increased radiolucency representing air in the expected location of the urinary bladder (arrows). (b) Contrast-enhanced CT scan obtained at the same level helps confirm the presence of multiple diffuse cystic collections of gas within the bladder wall (arrows). The bladder lumen is filled with contrast material (*).

View larger version (176K): [in a new window]   Figure 19b.  Emphysematous cystitis. (a) Pelvic radiograph obtained with the patient upright demonstrates circumlinear streaks of increased radiolucency representing air in the expected location of the urinary bladder (arrows). (b) Contrast-enhanced CT scan obtained at the same level helps confirm the presence of multiple diffuse cystic collections of gas within the bladder wall (arrows). The bladder lumen is filled with contrast material (*).

View larger version (145K): [in a new window]   Figure 20a.  Emphysematous cystitis in an 81-year-old diabetic man undergoing treatment for acute pancreatitis. (a) Contrast-enhanced arterial-phase CT scan through the pelvis shows a Foley catheter (arrowhead) and a rectal tube with a balloon cuff (thick arrow). There is a rounded collection of air within the urinary bladder (*) as well as multiple smaller locules of air more peripherally (thin arrows). (b) Delayed CT scan obtained at the same level shows contrast material within the bladder lumen (arrow). Both the large (*) and small collections of gas are clearly seen to be within the thickened anterior bladder wall rather than the bladder lumen.

View larger version (143K): [in a new window]   Figure 20b.  Emphysematous cystitis in an 81-year-old diabetic man undergoing treatment for acute pancreatitis. (a) Contrast-enhanced arterial-phase CT scan through the pelvis shows a Foley catheter (arrowhead) and a rectal tube with a balloon cuff (thick arrow). There is a rounded collection of air within the urinary bladder (*) as well as multiple smaller locules of air more peripherally (thin arrows). (b) Delayed CT scan obtained at the same level shows contrast material within the bladder lumen (arrow). Both the large (*) and small collections of gas are clearly seen to be within the thickened anterior bladder wall rather than the bladder lumen.

View larger version (157K): [in a new window]   Figure 21a.  Gas gangrene of the uterus in a 32-year-old postpartum patient. (a) Scout radiograph from an intravenous urogram demonstrates a large region of heterogeneously increased radiolucency centered within the pelvis representing mottled air (arrows). Discrimination between uterine and urinary bladder gas is difficult. (b) Delayed radiograph shows contrast material within the urinary collecting system and bladder that is clearly separate from the more posterior intrauterine gas.

View larger version (161K): [in a new window]   Figure 21b.  Gas gangrene of the uterus in a 32-year-old postpartum patient. (a) Scout radiograph from an intravenous urogram demonstrates a large region of heterogeneously increased radiolucency centered within the pelvis representing mottled air (arrows). Discrimination between uterine and urinary bladder gas is difficult. (b) Delayed radiograph shows contrast material within the urinary collecting system and bladder that is clearly separate from the more posterior intrauterine gas.

View larger version (190K): [in a new window]   Figure 22a.  Intrauterine gas. (a) Contrast-enhanced CT scan (enteric contrast material) through the pelvis obtained in a 27-year-old woman with fever who had recently given birth demonstrates a focal fluid collection with associated small gas collections within the anterior myometrium (black arrow). There is free fluid within the pelvis (white arrow). (b) Contrast-enhanced CT scan (enteric contrast material) through the pelvis obtained in a 36-year-old woman demonstrates a large soft-tissue mass (short arrows) containing multiple irregular gas collections (long arrows). The mass proved to be a large, infarcted uterine leiomyoma.

View larger version (179K): [in a new window]   Figure 22b.  Intrauterine gas. (a) Contrast-enhanced CT scan (enteric contrast material) through the pelvis obtained in a 27-year-old woman with fever who had recently given birth demonstrates a focal fluid collection with associated small gas collections within the anterior myometrium (black arrow). There is free fluid within the pelvis (white arrow). (b) Contrast-enhanced CT scan (enteric contrast material) through the pelvis obtained in a 36-year-old woman demonstrates a large soft-tissue mass (short arrows) containing multiple irregular gas collections (long arrows). The mass proved to be a large, infarcted uterine leiomyoma.

View larger version (140K): [in a new window]   Figure 23.  Vaginitis emphysematosa. Lateral radiograph of the pelvis shows discrete, diffuse cystic gas collections within the vaginal wall (arrows).

View larger version (167K): [in a new window]   Figure 24a.  Fournier gangrene in a 66-year-old diabetic man with diffuse soft-tissue swelling and crepitus at physical examination. Longitudinal (a) and transverse (b) scrotal US images demonstrate high-amplitude echoes within the thickened scrotal tissues (arrows), a finding that corresponds to gas from necrotizing fasciitis. There is no involvement of the testicles (t).

View larger version (171K): [in a new window]   Figure 24b.  Fournier gangrene in a 66-year-old diabetic man with diffuse soft-tissue swelling and crepitus at physical examination. Longitudinal (a) and transverse (b) scrotal US images demonstrate high-amplitude echoes within the thickened scrotal tissues (arrows), a finding that corresponds to gas from necrotizing fasciitis. There is no involvement of the testicles (t).