AJR 2000; 174:1337-1338
© American Roentgen Ray Society
Chest Radiographic Diagnosis of Stomach Abnormality
M. Herbert Nathan1 and
William M. Shannon1,2
1
North Phoenix Medical Specialists, 3023 E. Sierra Vista Dr., Phoenix, AZ
85016-8901.
2
John C. Lincoln Hospital, 9100 N. Second St., Phoenix, AZ 85020.
Received August 2, 1999;
accepted after revision November 1, 1999.
Address correspondence to M. H. Nathan.
Introduction
Although subdiaphragmatic abnormalities can sometimes be diagnosed on chest
radiography, to our knowledge, the diagnosis of gastric lesions on chest
radiography has not been reported. On chest radiography, if a nodule or mass
is suggested in the air-containing gastric fundus, the possibility that this
might be a lesion is, of course, considered. However, in our experience, most
masses seen on chest radiography are pseudotumors, and it would be helpful to
have an inexpensive, easy-to-perform examination to differentiate a
pseudotumor from an abnormality before subjecting patients to expensive,
complicated diagnostic procedures. A practical method of determining which
patients require additional examinations is presented.
Materials and Methods
When a masslike shadow is seen in the gastric fundus on the chest
radiograph, a simple, inexpensive means of determining whether the shadow
represents a pseudotumor or an abnormality is to repeat the chest radiography
after the patient, fasting for 4 hr or more and cautioned not to belch, has
ingested approximately 0.25 1 of a carbonated drink or a packet of E-Z-GAS
effervescent crystals (E-Z-EM, Westbury, NY) in approximately 0.25 1 of water.
Either method distends the stomach with carbon dioxide gas and fluid. If the
mass disappears, the shadow can be presumed to have been a pseudotumor and no
additional studies are needed. If the mass persists, CT or an upper
gastroinestinal examination should be performed to determine what this shadow
represents.
Results
A masslike shadow in the gastric fundus was seen in 18 patients on chest
radiography. The shadow was no longer present on repeated chest radiography,
performed after gas distention of the fasting stomach, in 14 patients.
Follow-up for 1-3 years indicated that none of these 14 patients developed a
significant gastric or liver abnormality.
The filling defect in the gastric fundus persisted in four patients after
gas distention, and additional special studies were deemed necessary to rule
out disease. In each of these patients, a CT scan revealed the cause in the
adjacent portion of the left lobe of the liver. An upper gastrointestinal
examination, performed in two of these patients, was less sensitive and
revealed no abnormality.
Discussion
When gas distention of the gastric fundus causes a masslike or nodular
shadow in the gastric fundus on chest radiography to disappear, the filling
defect was probably caused by mucosal folds (Fig.
1A,1B)
or food retention (Fig.
2A,2B).
However, should the filling defect persist in the gastric fundus after gas
distention, it is considered an abnormality in the stomach or adjacent
structure and additional studies are required. In the four patients in whom
the masslike shadow persisted in the gastric fundus, CT scans revealed the
cause to be in the adjacent liver. One abnormality was a cavernous hemangioma
(Fig.
3A,3B,3C),
two were liver metastases, and one was an unusual left lobe of the liver that
pressed on the medial margin of the gastric fundus. Gastric varices, masslike
lesions in the adjacent spleen, lymphadenopathy adjacent to the gastric wall,
and adjacent aneurysms are thought to cause filling defects in the gastric
fundus, which can be revealed by CT but possibly not by upper gastrointestinal
examination. Although either of these examinations should visualize gastric
polyps, carcinomas, or lymphomas, in our experience, contrast-enhanced CT of a
fasting, gas-distended stomach is the better choice in all cases to determine
the cause. A filling defect in the air-containing stomach, unchanged on chest
radiography over a period of 2 years or more, as occurred in two additional
cases, should be considered either a pseudotumor or a benign lesion of no
significance.
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Fig. 1B , —53-year-old woman who underwent radiography at routine physical
examination. Radiograph obtained after patient drank 0.25 l of carbonated
beverage shows gas distention of fasting stomach and normal gastric fundus.
Note absence of mass seen in A, which is considered to have been caused
by mucosal folds.
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Fig. 2A , —77-year-old woman taking medication for gastrointestinal symptoms
underwent chest radiography as part of her examination. Initial chest
radiograph reveals air-outlined nodular shadow (arrow) at junction of
gastric fundus and pars media.
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Fig. 2B , —77-year-old woman taking medication for gastrointestinal symptoms
underwent chest radiography as part of her examination. Gas distention of
fasting stomach by 0.25 l of carbonated beverage causes disappearance of
nodular shadow indicating that it was pseudotumor probably caused by food.
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Fig. 3B , —34-year-old woman complaining of sore throat. Second chest
radiograph immediately after fasting patient ingested 0.25 l of carbonated
beverage shows persistence of nodular shadow (arrows).
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Fig. 3C , —34-year-old woman complaining of sore throat. CT scan in early
phase of contrast enhancement showing appearance typical of cavernous
hemangioma (arrow) in left lobe of liver overlying gastric cardia
with contrast medium in margin of lesion but absent centrally until 10 min
later.
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In conclusion, a second chest radiograph after gas distention of the
fasting stomach is a simple, inexpensive, and well-tolerated means of
establishing whether a nodular or masslike filling defect in the gastric
fundus represents an abnormality, requiring special studies, or is a
pseudotumor requiring no additional workup.
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Introduction
Materials and Methods
