Anatomy and technique in evaluating the esophagus

Anatomy

and Technique

in Evaluating

the Esophagus

David W. Gelfand and David J. Ott

T

HE examination of the esophagus is a neglected area of gastrointestinal radiology. Too often the radiologic study consists of observing the patient swallow half a cup of barium suspension as a prelude to the upper GI series, the only radiograph being a single spotfilm of the esophagogastric junction. Effective radiologic evaluation is not that simple, however, and requires understanding of both the pertinent anatomy of the esophagus and a variety of examination techniques. For the purposes of this discussion, the hypopharynx is included as a part of the esophagus. Thus, there are four anatomic subdivisions of the esophagus meaningful to the radiologist: the hypopharynx, the cervical esophagus, the thoracic esophagus, and the esophagogastric junction. Each of these regions possesses its own unique anatomy and pathology, and requires different forms of radiographic examination for thorough evaluation. ANATOMIC

CONSIDERATIONS

The Hypopharynx

The hypopharynx extends from the epiglottis to the esophageal inlet. Because it is not easily accessible to visual inspection, ability to examine the hypopharynx radiographically is of particular importance. The anatomy of the hypopharynx is best appreciated on double contrast films in the frontal view (Fig. 1A, B). Superiorly, the epiglottis is seen as a barium-coated arcuate shadow, superimposed by the valleculae. The epiglottis should be smoothly arched, but the symmetrical val-

From School of David Bowman Associate Medicine. Reprint Celfand, School of o 1981 0037-I

168

the Department of Radiology, Bowman Gray Medicine. Winston-Salem, N.C. W. Gelfand, M.D.: Professor of Radiology, Gray School of Medicine: David J. Ott, M.D.: Professor of Radiology, Bowman Gray School of requests should be addressed to David W. M.D., Department of Radiology, Bowman Gray Medicine, Winston-Salem, N.C. 27103. by Grune & Stratton, Inc. 98X83/1

603-0004%02.00/0

leculae often contain small filling defects representing lymphoid tissue of the lingual tonsil. Most of the hypopharynx is bounded on each side by the outer margins of the piriform sinus, which has a pointed inferior recess. Connecting the inferior tips of each piriform sinus is an arched line of barium representing the margin of contact between the posterosuperior aspect of the larynx and the posterior wall of the hypopharynx. Inferiorly, the hypopharynx merges into the esophagus at the esophageal inlet, which lies anterior to the sixth cervical vertebra. This most inferior section of the pharynx is normally empty of air and barium at rest, and is best outlined during passage of a barium bolus. The lateral view of the hypopharynx is more complex due to superimposition of images (Fig. 1C). Superiorly, the two valleculae are superimposed. The epiglottis is well seen in profile. The superimposed aryepiglottic folds slant posteriorly downward from the epiglottis to the arytenoid cartilages. The piriform sinuses are also superimposed, but the posterior pharyngeal wall is well shown. Inferiorly, the cricopharyngeus muscle causes an indentation on the posterior aspect of the pharyngoesophageal junction. The major muscles of the pharynx consist of the superior, middle, and inferior constrictors, the latter including the cricopharyngeus. These form the posterior and lateral borders of the pharynx. An area of muscular dehiscence (Killian triangle) exists posteriorly in the midline between the oblique and horizontal fibers of the inferior constrictor. In response to elevation of pressure during deglutition, the pharyngeal mucosa may protrude through this gap, forming a Zenker diverticulum (Fig. 2). The most important structure anterior to the hypopharynx is the larynx, which is partially enveloped by the hypopharynx. The structures of greatest radiologic importance lateral to the pharynx are the cervical lymph nodes and the thyroid and parathyroid glands. The cervical spine lies posteriorly, and large osteoarthritic spurs on the anterior margins of the cervical vertebrae may displace or indent the posterior pharyngeal wall, a potential cause of dysphagia. Seminars

in Roantganology,

Vol. XVI,

No. 3 (July),

1981

ANATOMY

AND

TECHNIQUE

Fig. 1. Normal hypopharynx on double contrast films. (A) Frontal view. The epiglottis is seen as a curvilinear structure (arrows) just above the valleculae. IB) Multiple small filling defects in the valleculae, representing lymphoid tissue of the lingual tonsil. (C) Lateral view. The epiglottis (arrows) is well seen in profile. Superimposed aryepiglottic folds (arrowheads) slant posteriorly.

GELFAND

170

AND

OTT

distended, but shows several slender longitudinal folds when collapsed. The internal circular and external longitudinal muscular coats of the cervical esophagus are composed of striated muscle, which contributes to the rapid passage of a bolus through the region. The musculature of the cervical esophagus is immune to diseases of smooth muscle, such as scleroderma, that affect the lower

Fig. 2. Posteriorly the level of the sixth postcricoid impression level.

Cervical

protruding cervical (arrow)

Zenker vertebra. anteriorly

diverticulum at There is a slight at the same

Esophagus

This short segment commences anterior to the sixth cervical vertebra and continues into the thoracic inlet where, without any localizing feature, it becomes the thoracic esophagus. The cervical esophagus is difficult to examine radiographically because peristalsis at this level is extremely swift, making filming of the fully distended cervical esophagus a fortuitous adventure. The most effective radiographic method is use of a motion recording tine- or videoradiographic device during swallowing. Basically a featureless tube, the internal anatomy of the cervical esophagus is simple except for the presence on its anterior wall of a venous plexus that forms an irregular rounded or slightly web-like indentation (Fig. 2). This is a normal finding and has been called the postcricoid impression.’ This normal vascular impression should not be confused with either a neoplasm or a cervical esophageal web. The cervical esophageal mucosa is smooth when

Fig. 3. Thin of the collapsed

smooth longitudinal esophagus.

folds

along

the

course

ANATOMY

AND

171

TECHNIQUE

esophagus, but diseases that involve striated muscle, such as amyotrophic lateral sclerosis, may alter its function.2 The important relations of the cervical esophagus lie laterally: the lateral lobes of the thyroid gland, the inferior pair of parathyroid glands, and the cervical lymph nodes. Enlargement of these structures may deviate or constrict the cervical esophagus (Fig. 3). The relationship to the trachea anteriorly is important in that tracheoesophageal fistula may develop following trauma or surgery in the region. Thoracic

Esophagus

The esophagus is approximately 25 cm in length, and its longest segment is the thoracic

Fig. 4. Oblique view showing focal deviation tases.

esophagus.It is the segment most often affected by serious intrinsic pathology. The thoracic esophagusalso has complex relations to adjacent structures, with radiologic implications. The thoracic esophagus lies anterior to the thoracic vertebrae and slightly to the left of midline. Major deviations in its course occur at the aortic arch, where it is deviated to the right, and at the level of the heart, where it arches posteriorly. The mucosa of the thoracic esophagus is smooth and featureless. The lumen is tubular, enlarging proximal to the cardiac orifice to form the vestibule or phrenic ampulla. When it is collapsed, several smooth longitudinal folds course its entire length (Fig. 3).

of the upper thoracic esophagus due to mediastinal nodal metasthe

Fig. 5. Traction diverticulum level of the carina.

of the

midesophagus

at

172

The muscular coat of all but the most proximal portion of the thoracic esophagus is composed of inner circular and outer longitudinal fibers of smooth muscle. The predominance of smooth muscle in the thoracic esophagus contributes to slower peristalsis, and it is more frequently affected by motor disorders. Relations of the thoracic esophagus are complex and are best described in connection with the common entities causing its deviation or invasion. Lymph nodes lie anterior and lateral to the thoracic esophagus over much of its course,

GELFAND

AND

OTT

particularly near the carina. Their enlargement may deviate the esophagus, the direction depending on the location of the nodes (Fig. 4). Granulomatous infection of adjacent lymph nodes may cause a traction diverticulum due to contraction during healing (Fig. 5). Aortic tortuosity and dilatation may also deviate the esophagus. Aneurysm of the aortic arch may exaggerate the normal aortic impression (Fig. 6A). Lengthening and tortuosity of the thoracic aorta may pull the midthoracic esophagus posteriorly and to the left. An ectatic and

Fig. 6. (A) Effects of aOrtiC dilatation and tortuosity. Aortic arch enlargement causing both general and fowl impressions (arrows) on the esophagus. Right oblique view. (8, facing page) Sharp angulation of the lower esophagus due to uncoiling of the aorta. Left oblique view.

ANATOMY

AND

TECHNIQUE

173

uncoiled aorta may deviate the lowest portion of the thoracic esophagus anteriorly, causing sharp angulation of the esophagus where it crosses the aorta before entering the esophageal hiatus, a cause of dysphagia in the elderly (Fig. 6B). Cardiac enlargement may deviate the distal thoracic esophagus posteriorly; the shape and location of the deviation is helpful in determining specific chamber enlargement. The importance of proximity of the tracheobronchial tree anteriorly lies in the occurrence of tracheo-

Fig.

page.

esophageal fistula, usually chogenic carcinoma. Esophagogastric

from invasive bron-

Junction

This region is of particular radiologic importance due to the prevalence of hiatus hernia and reflux esophagitis. The transition from esophagus to stomach is not simple, yet must be understood if hiatal hernia is to be reliably detected. Though hiatus hernia per se may be of minor clinical significance, its presence has an impor-

GELFAND

174

tant permissive function in the development of reflux esophagitis,3 a common and often distressing condition. The most apparent transition from esophagus to stomach is at the mucosal surface. The smooth squamous-lined esophageal mucosa changes at the Z-line to the columnar epithelium of the gastric mucosa, which has a fine knobby texture known as the areae gastricae. With double contrast films, this mucosal transition is directly visible in many patients, and we believe that when located above the hiatus it reliably indicates hiatal hernia (Fig. 7A).4 Another mucosal feature at the esophagogastric junction is the lower esophageal ring,’ also referred to as the transverse mucosal fold6 or B ring.7 The Schatzki ring,’ a web-like structure, may be an exaggerated lower esophageal ring. The lower esophageal ring forms the lower limit of the segment of distal esophagus known as the vestibule. The ring is normally tucked within the hiatus. However, with the distal esophagus fully distended the ring may be visible above the esophageal hiatus in the presence of hiatal hernia (Fig. 7B). The muscular transition from esophagus to stomach also produces radiologic landmarks. The proximal end of the vestibule is defined by a broad muscular constriction known as the muscular ring, contractile ring, or A ring.’ Another landmark is the indentation on the lateral- side of the esophagogastric junction caused by the gastric sling fibers, a muscle bundle that courses up the lesser curvature of the stomach, around the lateral aspect of the esophagogastric junction, and back down the lesser curvature.’ With herniation, a distinct notch on the lateral aspect of the esophagogastric junction may be caused by the sling fibers (Fig. 7C). TECHNICAL

CONSIDERATIONS

Four examination modalities can be applied to the radiographic evaluation of the esophagus: full column technique, mucosal relief films, double contrast studies, and motion recording. Their proper application is crucial in obtaining maximum information from the esophageal examination. Full Column Technique This is a single contrast technique and is the basic method of examining any hollow viscus. It

AND

OU

simply requires filling the organ with barium, observing it fluoroscopically, and radiographing it in two or more views. The full column examination of the esophagus is best obtained with the patient in the horizontal position drinking barium through a straw. Maximum distension is achieved by having the patient swallow barium rapidly and performing the Valsalva maneuver. Together these efforts suppress primary peristalsis and exert a pinchcock effect at the level of the diaphragm, causing the barium to accumulate in the esophagus. The Valsalva maneuver also draws the diaphragm downward, encouraging better visualization of the esophagogastric junction. Two views of the barium-distended esophagus are necessary to demonstrate small contour changes and filling defects. There is disagreement among GI radiologists as to the appropriate views; most employ some combination of frontal, oblique, and lateral views in the prone position. The density of the barium used affects the potential accuracy of the full column examination. Regardless of barium density, virtually all circumferential and most noncircumferential lesions will be seen as a contour defect (Fig. 8). However, with dense barium, small lesions not demonstrable in profile may be missed.” Thus, examinations employing high density barium require that full column films be supplemented by mucosal relief or double contrast films to avoid failures in detection of small lesions. Many esophageal disorders are well shown with full column technique: Circumferential carcinomas are easily demonstrated, because the lesion is relatively nondistensible. Strictures are reliably detected because of the ease of achieving maximal distension (Fig. 9A). Uncomplicated reflux esophagitis also may cause a more subtle lack of distensibility. Large esophageal ulcers associated with reflux esophagitis and often accompanied by stricture are generally well demonstrated (Fig. 9B). They are more easily detected with moderate distention, since an overly distended barium-filled esophagus may obscure the ulcer. Small ulcerations are difficult to demonstrate for the same- reason. Hiatus hernias are usually best demonstrated on a full column examination performed in the

Fig. 7. (A) Hiatus hernia. The herniated stomach is identified by the reticulated pattern of the areae gastricae. Transition between this pattern and the smoothly coated esophagus represents the esophagogastric mucosel junction. (8) The hernia is identified by the lower esophageal mucosal ring (closed arrows) demarcating the lower end of the esophageal vestibule. The tubulovestibular junction or A level (open arrows) represents the upper end of the vestibule. Other signs of hiatal herniation shown hare include a patulous hiatus containing an excess number of folds. (C) Transient muscular or contractile ring (curved arrow) at the A level. Notch (straight arrow) due to indentation of the cardiac sling fibers.

176

GELFAND

Fig. 8. Small esophageal carcinoma seen as a contour defect on a full column examination of the esophagus.

prone position, since both distension and increased intraabdominal pressure are required to demonstrate the landmarks of the esophagogastric junction and promote their displacement above the hiatus. Extrinsic masses adjacent to the esophagus are most reliably demonstrated during full column examination, since the esophageal wall must be distended to the point of contact with the mass (Fig. 4). Although the full column examination is the basic method of studying the esophagus, several categories of lesions may go undetected if the examination is restricted to this technique. These include small plaque-like neoplasms, small ulcers and erosions, most cases of esophagitis,3 and many examples of esophageal varices.” Mucosal

Relief Films

By definition, examination in mucosal relief consistsof introducing sufficient barium to coat the esophagealmucosawithout filling the lumen. The result is demonstration of the smooth, longitudinal folds of the collapsed esophagus(Fig. 3). The best mucosal relief films are produced

AND

OTT

with a dense barium suspension or paste.12It must be sufficiently viscous and adhesive to deposit a coating that is not swept away by peristalsis. Several swallows may be necessary before the mucosais thoroughly coated. Because the amount of barium coating the esophageal folds on mucosal relief films may be minimal, these should be obtained in an oblique position, projecting the image of the esophagusaway from the spine. Lesions well shown on mucosal relief films are as follows: Neoplasms, benign and malignant, are well demonstrated since they interrupt the normally smooth esophagealfolds and produce their own irregular surface pattern. Mucosal relief films are thus useful in detecting small plaque-like or polypoid neoplasmsnot clearly demonstrated on full column views. Small ulcers and erosions are often demonstrated on mucosal relief films when not seenon the full column study. Since ulcers and erosions are somewhat rigid due to surrounding edema, barium may not be cleared from within the lesion by peristalsis. As a result, ulcers and erosions may be visible as collections of barium among the folds, most often in the distal esophagus in association with reflux esophagitis. The small ulcerations involving most of the esophagus in candidiasis are well demonstrated in mucosal relief. Vurices are effectively demonstrated on mucosal relief films, since esophageal luminal pressure is low, allowing the varices to distend with blood. Probanthine (30 mg parenterally) has been administered to further relax the esophagus and favor visibility of the varices (Fig. 10A).13 Early esophagitis may be evident on mucosal relief films as thickening and irregularity of the folds (Fig. 1OB).3 Lesions requiring distension for their demonstration are often invisible in mucosal relief. These include strictures, webs, rings, diverticula, and many casesof hiatus hernia. Double

Contrast

Technique

Ability to show small irregularities of the mucosa is the strength of double contrast methodology.‘3m’6The technique is also useful for examining the hypopharynx. Curiously, however, it is almost impossible to examine the cervical esophagusin double contrast.

ANATOMY

AND

TECHNIQUE

Fig. 9. (A) Peptic Another patient with

esophagitis stricture,

with hiatal

full hernia,

column technique. and large peptic

Barium suspensions for double contrast studies must be chosen for their ability to densely coat the mucosa. The very dense suspensions developed for double contrast upper gastrointestinal studies are ideal.” For the double contrast examination, the hypopharynx, proximal thoracic esophagus, and distal esophagus each require a separate technique. The hypopharynx is examined by having the patient take a single swallow of barium. The passing barium will coat the hypopharynx, the air normally present in the resting state creating the double contrast effect (Fig. 1). Films are taken in frontal and lateral projections, supplemented by oblique views as necessary. The proximal two-thirds of the thoracic

Stricture of the ulcer (arrows).

esophagus

with

associated

hiatal

hernia.

(S)

esophagus is examined by standing the patient in front of the fluoroscope and instructing him to swallow barium as rapidly as possible. Most patients swallow considerable air with the barium; the barium coats the surface of the esophagus as the air maintains distension (Fig. II). The double contrast effect is not long lasting, however, and filming must be well timed. Double contrast views of the distal one-third of the thoracic esophagus are obtained with the patient in a prone or prone oblique position drinking barium via a large straw as rapidly as possible. Due to the normal posterior arc of the thoracic esophagus, ingested air will usually collect in the distal esophagus, producing a double contrast effect (Fig. 7A). Double

GELFAND

AND

OTT

Fig. 10. (A) Mucosal relief studies. Excellent visualization of esophageal varices. (6) Thickened irregular folds in moderate esophagitis, proven endoscopically. (Reproduced by permission of Gastrointestjnal Radiology.” )

contrast studies can also be obtained in the upright position, air eructated from the stomach distending the distal esophagus. Particularly well demonstrated on double contrast films are neoplasms of the esophagus (Fig. 1 1),‘43’5 small ulcers and erosions, and esophagitis (Fig. 12).18 Certain lesions are poorly shown on double contrast films: Varices often are not demonstrable, perhaps because the elevated luminaf pressure during double contrast filming tends to push blood out of the varices and flatten them. Small hiatal hernias, rings, etc., may also be difficult to demonstrate. Motion

Recording

Techniques

Image amplification opened the way to motion recording of the gastrointestinal tract. This has been particularly useful in the pharynx and esophagusbecauseof the rapid, intimately coor-

dinated events during swallowing. Several types of motion recording are available, each having strengths and weaknesses. Ordinary fluoroscopy is the basic form of motion recording, events being recorded in the mind of the fluoroscopist. Experienced fluoroscopists may not require a more permanent motion recording technique except when a subtle or unusual abnormality is encountered, or a lesion of the cervical esophagusis suspected. Television recording is currently the most useful form of motion recording. Images now have sufficient resolution to demonstrate small abnormalities, and reliability is excellent. Advantages include low initial cost and immediate review of the recording. Cine recording is still performed by those having the equipment. Advantages of tine include the permanent image and ease of film storage. Disadvantages include the cost and

ANATOMY

Fig. trast views carcin contra tained obliquity reversed

AND

TECHNIQUE

11. Double conand full column of a midesophageal loma. The double 1st view was obin the opposite and the print for comparison.

complexity of the equipment, cost of the film, the need for developing the film before viewing, and the required separate projector. Spot-film cameras record the output of the image amplifier on 100 mm or 105 mm film. Advantages include short exposure time, the ability to record 2-6 images per second, lower radiation exposure than standard films, ability to record many images without changing cassettes, and savings in film costs. Disadvantages include poorer resolution than conventional spot films, limited gray-scale. quality, inability to control spot-film kilovoltage, and cost and complexity of the apparatus. The popularity of spot-film cameras suggests that many radiologists feel that the advantages considerably outweigh the disadvantages. Rapid-sequence spot-filming is a recent and useful development. On certain modern fluoroscopes, the spot-film device can record 2-3

images per second for several seconds without changing cassettes. This in effect duplicates the rapid filming capability of a spot-film camera without its added expense. The applications of motion recording in the pharynx and esophagus are best discussed in terms of individual clinical problems. Evaluation of swallowing function is greatly aided by motion recording, since analysis of individual components of swallowing requires careful review.‘9.20 Radiography of the cervical esophagus is most effectively performed with a motion recording device. The rapid transit of barium through the cervical esophagus makes conventional spotfilming “chancy,” and a motion recording device insures that adequate images of the cervical esophagus distended by barium will be obtained. Esophageal dysmotility is best evaluated with motion recording techniques. The patient is

180

GELFAND

Fig. 12. Double esophagitis, showing surface pattern.

contrast thickened

studies of the thoracic esophagus in upright irregular folds. erosions, and ulcerations.

instructed to take single swallows, and the passage of each bolus is followed down the esophagus with the motion recording device. Closely spaced repeated swallows are avoided, since this reflexly inhibits the primary peristaltic wave.” Small diverticula and neoplasms are often best demonstrated with motion recording. Diverticula of the midesophagus or of the Zenker type may appear only during passage of a bolus and are easily documented with motion recording. Similarly, small neoplasms may be best demonstrated during a specific phase of esophageal peristalsis or distention. RECOMMENDED

EXAMINATIONS

As is evident from the above, there is almost no limit to the number of techniques for evaluating the esophagus. In practice, however, a

position. (Cl Candida

(A) Normal esophagitis

patient. with

AND

OTT

(B) Severe reflux a diffusely granular

routine must be adopted that extracts maximum information from a moderate expenditure of time and film. The following examinations are those employed by the authors in the setting of a referral and teaching hospital. They are overly thorough for many reasons,but can be modified to suit circumstances. The Esophagram

as a Separate

Examination

When the patient’s symptoms are localized to the esophagus or hypopharynx, an “esophagram” is often performed. The routine requires two cups of dense,250% barium suspension,four spot-films, and a few minutes time. (1) With the table upright, the patient holds a mouthful of the dense barium, his back and occiput against the table, the image amplifier collimated to the cervical region, and the chin raised to prevent superimposition of the mandi-

ANATOMY

AND

181

TECHNIQUE

ble on the hypopharynx. The motion recording device is started, the patient swallows, and progress of the bolus through the hypopharynx and cervical esophagus is recorded. With the patient breathing quietly, a frontal double contrast film of the hypopharynx is taken on a spot-film (Fig. 1). The patient is then turned to a lateral position and the sequence is repeated. (2) Still upright, the patient is turned to the left posterior oblique position (in respect to the table) and instructed to drink barium rapidly. Ingested air produces a double contrast view of the proximal three-fourths of the thoracic esophagus. This image is recorded on a 2-on-l spot-film, usually requiring two exposures (Fig. 11.4). (3) The patient is placed in the prone position, given a cup with a large diameter straw, and instructed to take a single swallow. If significant abnormal peristalsis is observed, additional single swallows are recorded for further analysis or for viewing with the referring physician. The patient then holds a deep breath and simultaneously drinks barium rapidly. When maximal distension is achieved, a radiograph of the barium-flled thoracic esophagus, including the hiatus, is taken on half a spot-film (Fig. 7B). The sequence is repeated in a steep right anterior oblique position.

(4) Using the same barium, a mucosal relief view of the coated but otherwise empty esophagus is obtained, recording it on half a spot-film (Fig. 4C). The patient is then instructed to drink barium rapidly, and a double contrast view of the distal esophagus is recorded on the second half of the film (Fig. 7A). Esophagography Gastrointestinal

During the Upper Examination

Evaluation of the hypopharynx and cervical esophagus is usually omitted, the examination consisting of (1) upright double contrast films of the thoracic esophagus, (2) recumbent views of the barium-tilled esophagus, and (3) prone mucosal relief and double-contrast views of the distal esophagus. These examinations have proven virtually 100%) effective in detecting carcinoma of the esophagusand 80-90s effective in the detection of the more severe forms of reflux esophagitis. The availability of television recording has greatly aided in the examination of the cervical esophagusand hypopharynx, as well as in the evaluation and documentation of motility disorders. With the use of this or a similar routine, one can be confdent of detecting the vast majority of significant lesionsin the esophagus.

REFERENCES I. Pitman RG, Fraser GM: The post-cricoid impression of the oesophagus. Clin Radio1 1965; 16:34-9. 2. Margulis AR, Koehler RE: Radiologic diagnosis of disordered esophageal motility. Radio1 Clin North Am 1976; 141429-39. 3. Ott DJ, Gelfand DW, Wu WC: Reflux esophagitis: Radiographic and endoscopic correlation. Radiology 1979; !30:58338. 4. Gelfand DW, Ott DJ: Areae gastricae traversing the esophageal hiatus: A sign of hiatus hernia. Gastrointest Radio1 1979; 4: 12779. 5. Goyal RK, Glancy JJ, Spiro HM: Lower esophageal ring. N Engl J Med 1970; 282:1298-1305 and 1970; 282:1355562. 6. Friedland GW, Melcher DH, Berridge FR, et al: Debatable points in the anatomy of the lower oesophagus. Thorax 1966; 21:487798. 7. Wolf BS: The inferior esophageal sphincterAnatomic, roentgenologic and manometric correlation, contradictions and terminology. Am J Roentgen01 1970; I 10:260&77. 8. Schatzki R, Gary JE: Dysphagia due to a diaphragm-

like localized narrowing in the lower esophagus (“lower esophageal ring”). Am J Roentgen01 1953; 70:9 I I -22. 9. Friedland CW: Historical review of the changing concepts of lower esophageal anatomy: 430 BC lY77. Am J Roentgen01 1978; I3 I :373-88. IO. Moss AA, Koehler RE, Margulis AR: Initial accuracy of esophagrams in detection of small esophageal carcinoma. Am J Roentgen01 1976; 127:909-13. I I. Cockerill EM, Miller RE, Chernish SM. et al: Optimal visualization of esophageal varices. Am J Roentgenol 1976; 126:5 12223. 12. Miller RE, Chernish SM, Brunelle RL. A comparative double-blind study of esophageal barium pastes. Gastrointest Radio1 1977; 2:163-g. 13. Yamada A, Kobayashi S, Kawai B. et al: Study on x-ray findings of early esophageal cancer. Australasian Radio1 1972; I6:238-46. 14. Goldstein HM, Dodd GD: Double-contrast examination of the esophagus. Gastrointest Radio1 1976. 1:3-6. 15. ltai Y, Kogure T, Okuyama Y, et aI: Superficial esophageal carcinoma--Radiological findings in doublecontrast studies. Radiology 1978: 126:597 601

GELFAND

182

16. Yamada A: Radiologic assessment of resectability and prognosis in esophageal carcinoma. Gastrointest Radio1 1979; 4:213-8. 17. Gelfand DW: High density, low viscosity barium for fine mucosal detail on double-contrast upper gastrointestinal examinations. Am J Roentgen01 1978; 130:831-3. 18. Koehler RE, Weyman PJ, Oakley double-contrast techniques in esophagitis. 1980; 135:15-19. 19. Seaman

WB.

Examination

of

HF: Single- and Am J Roentgen01 the

pharynx.

In:

AND

Ol7

Margulis AR, Burhenne HJ, eds. Alimentary Tract Roentgenology (ed 2). St. Louis, C.V. Mosby, 1973:299-304. 20. Donner MW, Siegel CI: The evaluation of pharyngeal neuromuscular disorders by cinefluorography. Am J Roentgenol 1965; 94:299-307. 21. Dodds WJ: Current concepts of esophageal motor function: Clinical implications for radiology. Am J Roentgenol 1977; 128549%61. 22. Ott DJ, Wu WC, Gelfand DW: Reflux esophagitis revisited: Prospective analysis of radiologic accuracy. Gastrointest Radio1 198 I; 6:1-7.