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6 Timed Barium Swallow inForegut Disease
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References
1. Blonski W, Kumar A, Feldman J, Richter JE.Timed barium swallow:
diagnostic role and predictive value in untreated achalasia,
Esophagogastric junction outow obstruction, and non-achalasia dysphagia. Am J Gastroenterol. 2018;113(2):196–203.
2. Dempsey DT.Barium upper GI series in adults: a surgeon’s perspective.
Abdom Radiol N Y. 2018;43(6):1323–8.
3. de Oliveira JM, Birgisson S, Doinoff C, Einstein D, Herts B, Davros W,
etal. Timed barium swallow: a simple technique for evaluating esophageal emptying in patients with achalasia. AJR Am J Roentgenol.
1997;169(2):473–9.
4. Neyaz Z, Gupta M, Ghoshal UC. How to perform and interpret timed
barium esophagogram. J Neurogastroenterol Motil. 2013;19(2):251–6.
5. Schlottmann F, Neto RML, Herbella FAM, Patti MG.Esophageal achalasia: pathophysiology, clinical presentation, and diagnostic evaluation.
Am Surg. 2018;84(4):467–72.
6. Richter JE. Tailoring therapy for achalasia. Gastroenterol Hepatol.
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7. Kostic S, Andersson M, Hellström M, Lönroth H, Lundell L.Timed barium esophagogram in the assessment of patients with achalasia: reproducibility and observer variation. Dis Esophagus Off J Int Soc Dis
Esophagus. 2005;18(2):96–103.
8. Richter JE, Clayton SB.Diagnosis and management of esophagogastric
junction outow obstruction. Am J Gastroenterol. 2019;114(4):544–7.
9. Clayton SB, Patel R, Richter JE.Functional and anatomic esophagogastric junction outow obstruction: manometry, timed barium Esophagram
ndings, and treatment outcomes. Clin Gastroenterol Hepatol Off Clin
Pract J Am Gastroenterol Assoc. 2016;14(6):907–11.
10. Vaezi MF, Baker ME, Richter JE.Assessment of esophageal emptying
post-pneumatic dilation: use of the timed barium esophagram. Am J
Gastroenterol. 1999;94(7):1802–7.
11. Vaezi MF, Baker ME, Achkar E, Richter JE.Timed barium oesophagram:
better predictor of long term success after pneumatic dilation in achalasia
than symptom assessment. Gut. 2002;50(6):765–70.
12. Kostic SV, Rice TW, Baker ME, Decamp MM, Murthy SC, Rybicki LA,
etal. Timed barium esophagogram: a simple physiologic assessment for
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13. Andersson M, Lundell L, Kostic S, Ruth M, Lönroth H, Kjellin A, etal.
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14. Blonski W, Kumar A, Feldman J, Richter JE.Timed barium swallow for
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J. Sujka et al.
Role ofCT Imaging
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inForegut Physiology
andBenign Pathology
MaggieL.Diller andDanielShouhed
Introduction
Computed tomography (CT) is an important diagnostic tool utilized throughout the perioperative period and helps guide clinical decision-making. While the functional or dynamic
information provided by CT is limited, several studies support
its role in the evaluation of both benign and malignant pathologies of the upper gastrointestinal (GI) tract. CT imaging demonstrates both the organ or system of interest and more distant
regions—a unique feature when compared to other imaging
modalities and an important adjunct to direct mucosal visualization via endoscopy. Recent advances in CT technology, in particular the routine use of multidetector computed tomography
(MDCT), have further enhanced our ability to evaluate the upper
GI tract [1]. While traditional single-section spiral CT was limited by a relatively large section thickness, MDCT uses thin col-
7
M. L. Diller (*)
Division of General and GI Surgery, Department of Surgery, Emory
University, Atlanta, GA, USA
e-mail: maggie.l.diller@kp.org
D. Shouhed
Cedars Sinai Medical Center, Los Angeles, CA, USA
© Society of American Gastrointestinal and Endoscopic Surgeons
(SAGES) 2023
A. D. Patel et al. (eds.), The SAGES Manual of Physiologic
Evaluation of Foregut Diseases,
https://doi.org/10.1007/978-3-031-39199-6_7
81
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limation and is able to cover a large volume in a very short scan
time [2]. This creates high-quality, multiplanar reformation and
allows for three-dimensional visualization, signicantly improving the diagnostic capability of CT imaging [1]. In this chapter,
we will focus on the role of CT imaging in the diagnosis and
evaluation of benign foregut pathology, including gastroesophageal reux disease, hiatal hernias, achalasia, and its specic
applications in the postoperative period.
M. L. Diller and D. Shouhed
CT Technique
High spatial resolution with proper distension of the esophagus,
stomach, and small bowel is necessary for optimum CT technique. Proper timing of intravenous (IV) contrast media injection
is especially important with MDCT imaging given short scan
times. Administration of IV contrast 30s prior to image acquisition will capture the arterial phase and further detail the mucosa
and gastroesophageal junction (GEJ) wall. When evaluating for
mass or tumor, images obtained during the portal venous phase of
the entire abdomen will be useful in the detection of distant disease (60-s delay between administration of IV contrast and image
acquisition). Additionally, distension of the upper GI tract with
oral contrast facilitates the detection of subtle changes within the
esophageal/gastric/intestinal wall.
In general, recommendations for imaging of the upper GI tract
include a fasted state for at least 6h followed by administration of
1000–1500 mL of oral contrast [1, 2]. Positioning the patient
prone or in a lateral decubitus position while ingesting contrast
has also been shown to improve image acquisition of the esophagus and stomach [1, 2]. Over time, acquired expertise in specic
pathologies has led to the renement of these generalized recommendations. Nuances in CT technique specic to a certain disease
will be discussed in more detail below. Ideally, CT examinations
will be performed on either a 16- or 64-detector row scanner with
a 0.5-s tube rotation. For diagnostic viewing, reconstruction of
3–4-mm-thick axial sections should be obtained along with
3–5-mm-thick coronal and sagittal sections along the length of the
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esophagus, stomach, and proximal small bowel [1, 2]. Multiplanar
reformation is optional but may be useful when diagnostic questions remain unresolved.
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Gastroesophageal Reux Disease (GERD)
andHiatal Hernias
Gastroesophageal reux disease (GERD) is associated with a
broad spectrum of symptoms and signicantly impacts the quality
of life. Prolonged reux has been associated with changes in the
esophageal squamous epithelium leading to Barrett’s esophagus
and increased risk of esophageal adenocarcinoma. While the gold
standard for evaluating reux esophagitis is endoscopy, contrasted
CT plays an important role in the initial evaluation of these
patients, particularly as GERD is a common cause of non-cardiac
chest pain [3]. The most common CT ndings for esophagitis,
irrespective of etiology, are circumferential esophageal wall
thickening, submucosal edema, and mucosal enhancement [3]. A
distal esophageal wall thickness of 5.0mm or greater predicts the
presence of esophagitis on endoscopy with a specicity of 88%
and sensitivity of 56% [4]. Additional CT ndings associated with
reux esophagitis include the presence of a target sign (ring
enhancement) and peri-esophageal lymphadenopathy; however,
these ndings are nonspecic [4].
Compared to upper endoscopy, CT imaging identies approximately 50–60% of sliding-type hiatal hernias [4]. Sliding-type
hiatal hernias predispose one to gastroesophageal reux due to
displacement of the proximal stomach and GE junction into the
posterior mediastinum with the resulting compromise of the lower
esophageal sphincter. While endoscopy is more sensitive, even
small sliding-type hiatal hernias may be seen on CT with Valsalva
or colonic distension.
Esophageal hiatal hernias comprise three types: sliding-type
hiatal hernia, paraesophageal hernia, and combined hernia.
Sliding hiatal hernia was described above and constitutes more
than 90% of esophageal hiatal hernias (HH). Type II paraesophageal hernias involve herniation of all or part of the stomach into
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M. L. Diller and D. Shouhed
the chest, while the gastroesophageal junction remains below
the diaphragm. It accounts for less than 10% of HH [5].
Typically, the gastroesophageal sphincter mechanism functions
normally in this setting and gastroesophageal reux does not
typically occur [5]. Instead, hemorrhage, incarceration, obstruction, and strangulation of the stomach and intestines are the
most common complications. Axial herniation of the stomach
results in a retrocardiac mass as the cardia is displaced into the
thoracic cavity. With CT, there is a demonstration of gastric
folds in this retrocardiac space, which is pathognomonic [5].
While most paraesophageal hernias are associated with xation
of the gastric cardia and a portion of the stomach herniated
alongside the esophagus, an extreme form of herniation can
occur in which all of the stomach is found within the thoracic
cavity and no such portions identied below the diaphragm [5].
This nding on CT is termed “upside down stomach” [5].
Surgical repair is frequently necessary; therefore, preoperative
imaging is crucial for the delineation of the hernia’s nature, the
extent of defect, and to identify obstruction or strangulation,
which would necessitate emergent intervention. Multi-slice CT
with sagittal, coronal, and 3D reformatted images has signicantly improved the diagnostic sensitivity of CT imaging in the
setting of all hiatal and diaphragmatic hernias [5]. CT scan often
depicts diaphragmatic discontinuity, intrathoracic herniation of
abdominal contents, and waist-like constriction of mesenteric
folds (the “collar sign”) [5]. If intestinal obstruction and strangulation occur, dilated intestinal segments with air–uid levels will
be seen within the thorax and abdomen. Omental vessels may be
seen as funicular-shaped densities, running longitudinally in the
superior to the inferior direction [5].
Gastric volvulus is a rare but potentially life-threatening condition that may occur in the setting of a hiatal or diaphragmatic
hernia. Gastric volvulus refers to at least 180° rotation of the
stomach and leads to gastric outlet obstruction, impairment of
vascularity, and eventual ischemia. Patients may have a nonspecic clinical presentation, which typically prompts diagnostic
imaging. CT scan is the initial examination of choice as it is both
sensitive and specic with an overall accuracy of 90% [6]. There
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are two main gastric volvulus subtypes—organoaxial and mesenteroaxial. Each has unique features on CT scan.
Organoaxial rotation involves rotation of the stomach along its
long axis passing through the gastroesophageal junction and
pylorus resulting in gastric obstruction. This is the most common
subtype and is associated with paraesophageal hernia and diaphragmatic hernia [6]. On CT, the inverted stomach has a horizontal lie with the greater curvature superior to the lesser curvature.
Mesenteroaxial rotation of the stomach occurs along its short
axis, perpendicular to the long axis. The stomach has a vertical lie,
and the antro-pyloric junction is displaced above the gastroesophageal junction.
Additional CT features with high sensitivity and specicity for
gastric volvulus include a transition point at the pylorus and stenosis at the hernia neck [6]. CT ndings indicative of overt ischemia include gastric wall edema, poor gastric wall enhancement,
perigastric uid, pneumatosis, pleural effusion, and pneumoperitoneum; while they occur infrequently, the ndings are highly
specic for gastric volvulus [6]. Of these, perigastric uid and the
presence of a pleural effusion have the highest sensitivities (30–
47% and 27–37%, respectively) for gastric volvulus [6].
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CT Imaging Pre- andPost-fundoplication
GERD refractory to medical therapy requires surgical intervention. Anti-reux operations aim to accomplish the following three
key steps: (1) reduction in any hiatal hernia by returning the LES
to the abdomen, (2) construction of a gastric wrap or fundoplication around the distal esophagus, and (3) re-approximation of the
diaphragmatic crura. Preoperative imaging is imperative prior to
anti-reux surgery. Traditionally, endoscopy and uoroscopybased upper GI series (UGI) are performed and provide sufcient
anatomic and functional detail. CT can be performed prior to surgery and may be helpful in the setting of large hiatal or paraesophageal hernias and in determining esophageal length and predicting
the need for an esophageal lengthening procedure. The 5-year
success rate for anti-reux operations is approximately 90%;
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however, early and late complications do occur with nearly 3% of
patients requiring redo fundoplication [7]. In cases of failed fundoplication, UGI or CT assist in the identication of the mechanism of failure and its functional consequences, the need for and
timing of additional surgery, and help to guide the choice of surgical repair [7].
MDCT with oral contrast is the preferred method of CT imaging for the evaluation of post-fundoplication anatomy. Positioning
the patient in the right anterior oblique position for image acquisition increases intra-abdominal pressure and enhances visualization of hiatal hernias, while eliminating the effect of gravity on
esophageal emptying [8]. Multiplanar and volumetric reconstructions for a 3D image are especially valuable in visualizing the
anatomical and spatial relationships between the esophagus, the
fundoplication and the stomach, and the diaphragm [8].
Persistent or recurrent symptoms of reux and/or persistent
postoperative dysphagia are the most common indicators of fundoplication failure. Such failures are usually due to a wrap that is
either too tight or too loose, a disrupted fundoplication, or an incorrectly positioned or herniated fundoplication. CT ndings are suggestive of a tight fundoplication include a narrowing of the distal
esophagus with proximal dilation [7]. A disruption of the fundoplication involves partial or complete breakdown of the wrap with a
recurrent hiatal hernia, both of which are evident on CT [7]. Various
ndings on CT may indicate an incorrectly positioned or herniated
wrap: The wrap may be intact and infra- diaphragmatic with herniation of only the proximal stomach into the chest, or there may be
complete migration of the stomach into the chest. Hourglass deformities may also occur. For example, in transdiaphragmatic wrap
herniation, an intact wrap and distal esophagus are visualized above
the diaphragm on CT with the diaphragmatic hiatus compressing
the stomach and creating an hourglass shape [7].
M. L. Diller and D. Shouhed
Achalasia
There are two types of achalasia— primary and secondary.
Primary achalasia is a benign disease characterized by incomplete
relaxation of the lower esophageal sphincter (LES) on swallowing
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and aperistalsis of the esophageal body. Secondary achalasia, or
pseudoachalasia, mimics the symptoms of primary achalasia but
typically results from submucosal inltration of the lower esophagus or proximal stomach by adenocarcinoma. Fluoroscopic-based
imaging with UGI is typically the initial imaging procedure when
achalasia is suspected [9]. This provides a global assessment that
includes swallowing function, esophageal and gastric morphology and motility, gastroesophageal reux, and abnormalities of
the gastric cardia and fundus. CT imaging is an important adjunct
when initial diagnostic studies are either equivocal for primary
versus secondary achalasia or worrisome for pseudoachalasia of
malignancy [10]. CT ndings of primary achalasia include longsegment dilation of the esophagus with little or no esophageal
wall thickening [9–11]. In contrast, CT ndings of secondary
achalasia typically include asymmetric esophageal wall thickening (wall thickness>5mm), irregular narrowing, or a soft-tissue
mass at the gastroesophageal junction [9–11].
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CT Imaging Post-myotomy
CT has been used in some centers as part of the initial diagnostic
evaluation for post-myotomy adverse events [12]. Compared to
uoroscopic-based studies, CT esophagrams appear more sensitive in detecting post-procedure contrast extravasation and have
the added benet of feasibility—CT imaging can be performed
at any time without the direct involvement of a radiologist [12].
To improve sensitivity in detecting small leaks, patients may be
given both thin and thick liquid contrast medium. Patients
should drink sequentially 3/4 of the thin and thick liquid contrast media followed by ingestion of the last 1/4 immediately
prior to the post- oral contrast scan [12]. Image reformation
should be done in the coronal and sagittal planes with 10-mm
thickness and 5-mm spacing.
The main CT ndings post-myotomy can be divided into frequent and reversible sequelae, such as pneumomediastinum,
pneumoperitoneum, and subcutaneous emphysema, and potential
adverse events, including pneumothorax, pleural effusion, pneumonitis, and focal atelectasis [12–14]. While there is a plethora of
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abnormal CT ndings following surgical or endoscopic myotomy,
less than 1% of patients typically require intervention based on
clinical symptoms. As such, routine chest CT for achalasia
patients is probably not warranted post-myotomy [13, 14].
M. L. Diller and D. Shouhed
CT Imaging Versus UGI inthePostoperative
Setting
In the assessment of postoperative complications, surgeons typically rely on one of two studies—uoroscopic-based UGI or CT
scan. There is increasing evidence to suggest that CT imaging is
the preferred modality in the postoperative period, particularly for
the detection of leaks. While UGI is very specic, its sensitivity is
lower than that of CT imaging, even with the use of thin barium
following a non-diagnostic study [15]. CT with the use of watersoluble contrast along with the evaluation of mediastinal gas has
been shown to signicantly raise the sensitivity and negative predictive value of CT in the detection of leaks following esophageal
surgery [15]. Studies evaluating the role of CT in the detection of
leaks following bariatric surgery support this modality as a more
sensitive and specic tool in the evaluation of postoperative complications [16]. Nevertheless, it has been suggested that real-time
images acquired during an UGI may offer a more accurate depiction of the magnitude and anatomic origin of a leak [17]. As such,
UGI remains a useful tool in guiding management decisions,
especially once a leak has been identied [16].
There are some additional advantages of CT imaging that
should be noted. CT will detect acute processes that may be
missed by UGI, i.e., abscess, ileus, early postoperative obstruction, and remnant/duodenal stump or staple line disruption [16].
As mentioned above, UGI is operator-dependent and requires the
presence of an expert radiologist both at the time of the study and
in the interpretation of results [16]. UGI is also more timeintensive for both the radiologist and the patient, and it requires
that the patient be able to tolerate standing upright, whereas a CT
scan may be performed entirely with the patient in the supine
position. Total radiation exposure is a consideration when decid-
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