Manometry and radiology. Complementary studies in the assessment of esophageal motility disorders

The relationship between radiological and manometric findings in esophageal motility disorders is poorly understood. Therefore, 20 subjects (4 normal; 13 diffuse spasm; 3 other motility disorders) were studied using synchronous manometry and videofluoroscopy with alternate 5-ml and 10-ml barium swallows. A total of 181 swallows were analyzed. Concordance between manometry and fluoroscopy was excellent for individual swallows (98%), groups of 5 swallows (97%), and final diagnoses (90%). Contraction onset intervals less than 0.8 s apart over 5 cm (velocity greater than 6.25 cm/s) were critical in determining abnormal bolus transit (98% sensitivity and positive predictive value). Radiologically, segmental tertiary activity (complete luminal obliteration) was always associated with disrupted primary peristalsis, but nonsegmental tertiary activity was often seen with normal bolus transit and did not have a specific manometric correlate. Four patterns of interrupted peristalsis radiologically were found--segmental tertiary contractions, a generalized esophageal contraction, absence of motor activity, or discoordinated "to-and-fro" movement. Surprisingly, nearly complete barium clearance occurred by the first two mechanisms in two thirds of swallows. Thus, the authors believe radiology and manometry are both excellent studies for identifying abnormal esophageal peristalsis. In difficult cases, these tests give complementary information because radiology assesses bolus movement while manometry provides quantitative pressure data.

Oropharyngeal function study: radiologic means of evaluating swallowing difficulty

The oropharyngeal function study is a videotaped radiographic examination of the oropharynx and cervical esophagus used in patients who are at major risk for aspiration because of swallowing difficulty. Preceding the radiographic evaluation, the patient is assessed clinically by a swallowing therapist who attends the examination with the radiologist. Close cooperation between the therapist and radiologist better defines the specific swallowing problems, avoids inadvertent aspiration of large amounts of contrast material, and best directs proper management of the patient. We describe our cooperative approach to evaluating oropharyngeal dysphagia.

Effects of liquid versus solid diet on colonic transit in humans. Evaluation by standard colonic transit scintigraphy

The effects of liquid versus solid diet on human colonic transit were investigated, and transit following cecal instillation of tracer was compared with transit following instillation in the proximal jejunum. In a randomized cross-over, single-blind fashion, 6 normal volunteers ingesting either normal solid foods or a liquid diet were studied using colonic transit scintigraphy. 111In-DTPA was instilled either into the cecum via a long intestinal tube or into the proximal jejunum via a feeding tube. Compared with the liquid diet, the solid diet slowed transit in the cecum and ascending colon (p less than 0.025) and delayed progression of the geometric center (p less than 0.05) during the first 4 h of the study. Transit from 18 to 48 h was similar on the 2 diets. On the solid diet, transit was similar whether 111In-DTPA was instilled into the proximal jejunum or into the cecum. Transit from the terminal ileum to the cecum was assessed in an additional 5 volunteers following jejunal instillation of 99mTc-DTPA. Cecal filling was rapid (T1/2 = 0.49 h) and complete in all subjects before the onset of cecal emptying. These results suggest that colonic transit is slower on a solid than a liquid diet and that jejunal instillation of radiopharmaceuticals should be suitable for colonic transit studies in most subjects.

Effects of hiatal hernia, reflux esophagitis, and glucagon on the quality of double-contrast esophagram

The possible effect of hiatal hernia, reflux esophagitis, and glucagon on the quality of the double-contrast esophagram was studied in 177 patients. Overall, the quality of the double-contrast esophageal views were judged poor in 46 (26%) patients and good in 131 (74%). No significant improvement in quality was evident in patients receiving glucagon, or in those with hiatal hernia or documented reflux esophagitis. Although the presence of gastroesophageal reflux or the lowering of esophageal sphincter pressure by glucagon would be expected to promote gaseous reflux from the stomach, no improvement in the quality of the double-contrast views of the esophagus was evident in our study.

Lymphomatous polyposis of the colon

Lymphoma of the colon is rare and has different radiographic presentations. The least common of these presentations is diffuse polyposis. Here we describe 4 cases of diffuse lymphomatous polyposis of the colon, each having a distinct radiographic appearance.

Radiographic and manometric correlation in achalasia with apparent relaxation of the lower esophageal sphincter

We compared the clinical, radiographic, and manometric findings in 10 patients with atypical achalasia showing complete lower esophageal sphincter (LES) relaxation to 39 patients with classic achalasia (i.e., incomplete LES relaxation). Those with atypical achalasia were younger (46.1 vs 60.6 years), had dysphagia of shorter duration (18.7 vs 45.7 mos), had lost less weight (8.2 vs 21.5 lbs), and had less esophageal dilatation (2.8 vs 3.9 cm). However, the mean LES pressures (34.5 vs 37.7 mmHg) and the esophagogastric junction calibers (4.5 vs 4.8 mm) were similar. Radionuclide esophageal emptying studies were done in 15 patients (6 with atypical achalasia; 9 with classic achalasia) and were abnormal in all. Most patients in both groups (90 and 92%) responded well to pneumatic dilatation. We conclude that achalasia with apparent LES relaxation may represent an early form of this motor disorder and that the radiographic findings remain characteristic except for less dilatation of the esophagus.

Esophageal motility: assessment with synchronous video tape fluoroscopy and manometry

Synchronous video tape fluoroscopy and manometry of the esophagus was performed in 11 subjects (seven men and four women; mean age, 49 years). Four had normal and seven had abnormal esophageal motility (diffuse esophageal spasm, n = 4; nonspecific esophageal motility disorder, n = 3) that was shown by previous manometry. A digital timer appeared on the video tape recording and marked the manometric tracing synchronously. Alternate 5-mL and 10-mL barium boluses were recorded for a total of 10 swallows per patient. Video tape examinations were reviewed prospectively, and the status of primary peristalsis and presence and severity of tertiary activity were noted. A total of 98 swallows (58 normal, 40 abnormal) were correlated, and a 96% agreement was found in assessing primary peristalsis. Overall results of fluoroscopic examinations of each subject during all swallows showed complete agreement with those of manometry; segregating the swallows into groups of five showed 92% concordance. Severe tertiary activity was invariably seen with abnormal primary peristalsis at fluoroscopy.

Inverted Meckel's diverticulum

Although Meckel's diverticulum is a relatively common anomaly, inverted Meckel's diverticulum has been reported rarely. We describe a 59-year-old woman with inverted Meckel's diverticulum located at the distal ileum simulating a benign tumor. Computed tomography showed a small mass with a central area of low fat density, and appearance not described previously.

Positive predictive value and posttest probability of diagnosis of colonic polyp on single- and double-contrast barium enema

The positive predictive value for a radiographic diagnosis of colonic polyp, the prevalence of polypoid disease, and posttest probability relative to patient age were studied. The positive predictive value for colonic polyp on single- and double-contrast barium enema was determined for 191 polyps found radiographically in 136 patients who also underwent colonoscopy for confirmation. Of 72 polyps seen in 54 patients on single-contrast examination, 59 were confirmed endoscopically; 110 of 119 polyps seen in 82 patients on double-contrast examination were confirmed similarly, giving positive predictive values of 82% and 92%, respectively. Positive predictive values per patient, disregarding the number of polyps present, were 87% (47/54) and 90% (74/82) for the single- and double-contrast examinations, respectively. False-positive errors were due to stool, air bubbles, haustration, and misinterpretation of an appendiceal stump. By using specificities derived from our prevalence of polypoid disease and previously reported sensitivities, we drew posttest probability curves showing that predictive values depend both on the chance of disease before the test is done and on the efficacy of the test used.

Hypertensive lower esophageal sphincter: what does it mean?

The hypertensive lower esophageal sphincter (LES) (mean LES pressure greater than 45 mm Hg; LES relaxation greater than 75%; normal peristalsis) is a poorly characterized motility disorder associated with chest pain and dysphagia. Therefore, we carried out a multidisciplinary study to assess esophageal pressures and function in 15 symptomatic hypertensive LES patients (3 men, 12 women; mean age, 53 years). On-line computer analysis showed a significant (p less than 0.05) increase in LES pressure (55.5 versus 14.9 mm Hg) and residual pressure (6.8 versus 1.1 mm Hg) as well as a decrease in percentage of LES relaxation (87 versus 93%) in patients compared with age-matched controls. All patients had normal peristalsis but 7 of 15 had nutcracker esophagus (mean distal amplitude, 216 mm Hg). No patient had evidence of impaired liquid transport on barium esophagram. The emptying of solids as assessed by radionuclide scans was normal in 14 of 15 patients. Of the 12 patients who completed both psychological inventories, nine had elevated scores on scales assessing anxiety and somatization. The heterogenous nature of this disorder is illustrated by a patient with a changeable narrowing in the distal esophagus associated with the transient impaction of a marshmallow. Dysphagia but not chest pain improved after pneumatic dilatation. We conclude that the hypertensive LES is a heterogenous disorder. Despite abnormal LES parameters, most patients have normal esophageal function, and frequent psychological abnormalities may contribute to their report of symptoms. A minority have abnormal esophageal transit.

Diffuse esophageal spasm: radiographic and manometric correlation

Diffuse esophageal spasm (DES) is characterized by substernal chest pain, dysphagia, and a manometric pattern of frequent simultaneous contractions with intermittently normal peristalsis. The authors correlated the radiographic and manometric findings in 17 patients with DES to better clarify the role of radiography in the evaluation of this uncommon motility disorder. Incomplete or absent primary peristalsis was observed on radiographs in 13 patients (76%), and mild to severe tertiary activity was seen in 12 patients (71%). The mean estimated thickness of the esophageal wall in patients with DES was 2.6 mm compared with 2.5 mm in an age-matched control group of 17 patients with normal esophageal manometric findings (P greater than .05). The authors conclude that most patients with DES show abnormal esophageal motility on radiographs, although the findings were nonspecific and required clinical and manometric correlation. Esophageal wall thickness was normal in patients with DES and appears to be an overemphasized sign in differentiating DES from other esophageal motility disorders.

Barium enema examination: sensitivity in detecting colonic polyps and carcinomas

We analyzed the sensitivity of the barium enema examination in 128 patients with 191 endoscopically proven colonic polyps and 12 carcinomas, relative to patient age, indications, and the type of examination used. Seventy-seven patients (60%) had rectal bleeding, and 51 (40%) patients with 87 lesions, including six carcinomas, did not. Overall roentgenographic sensitivity was 88%, with a 93% detection rate in patients less than 70 years old as compared to 76% for older patients. Sensitivity of single- and double-contrast barium enema examination was 82% and 91%, respectively. There were similar detection rates for lesions 1 cm or more in size (91% vs 95% for single- and double-contrast examinations, respectively), but double-contrast examination was slightly better at detecting smaller polyps (88%, vs 70% for single-contrast examination). Compared to colonoscopy, which has an average reported false-negative rate of 12% in detecting neoplasms, the barium enema is similarly reliable, less costly, and safer.

Impact of the barium enema on patient management

The medical records of 214 consecutive inpatients who had a barium enema examination were reviewed, and the clinical indications, efficacy of the barium enema, and patient outcome were correlated to determine the impact of the barium enema on patient management. The most frequent indications were rectal bleeding (33%), abdominal pain (31%), anemia (17%), weight loss (12%), and previous lesions needing reevaluation (12%). Diverticular disease (30%), colonic polyps (10%), and primary or secondary malignancies (12%) were the most common abnormalities detected radiographically. The sensitivity of the barium enema for colonic neoplasms was 89%, with only 1 small cecal polyp being undetected. The effects of barium enema on patient management were serious pathology excluded (64%), diagnosis made that changed therapy (24%), existing therapy continued (10%), and a further study ordered (2%). No serious or life-threatening lesion was missed by barium enema.

Colonic cleansing for radiographic detection of neoplasia: efficacy of the magnesium citrate-castor oil-cleansing enema regimen

To optimize detection of colonic polyps, we instituted a cleansing regimen of dietary restriction, hydration, magnesium citrate, castor oil, and a cleansing enema. We then conducted a review of serially performed barium enemas to determine the percentage of patients with clean colons in a mixed population of 500 inpatients and outpatients in whom this regimen had been used. The same regimen also was used before single- and double-contrast barium enemas were performed in 139 patients with 234 polyps, and radiologic-endoscopic correlation was used to determine the percentage of polypoid neoplasms detected. The review indicated that a clean colon had been achieved in 97% of the 500 cases. In an additional 1.4% of patients, fecal residue was limited to small amounts in the cecum or ascending colon. In only two cases (0.4%) did fecal material prevent an examination that was suitable for detection of large polypoid or circumferential lesions. The single- and double-contrast barium enemas detected 80% and 91%, respectively, of polypoid lesions of all sizes. Single-contrast examinations detected 94% of polyps 10 mm or larger and 72% of polyps 5-9 mm. Double-contrast studies detected 96% of polyps 10 mm or larger and 88% of those 5-9 mm. The results of this study indicate that with this regimen, fecal residue does not significantly interfere with the detection of colonic polyps via barium enema examination.

Oral cholecystography vs gallbladder sonography: a prospective, blinded reappraisal

In a prospective, blinded study of 205 patients, oral cholecystography (OCG) and sonography were compared in terms of how well each screened patients for gallbladder diseases. Among 23 patients who had pathologic confirmation of the diagnosis at cholecystectomy, OCG correctly diagnosed 20 cases (87%) while sonography diagnosed 18 (78%). Among 54 patients with an abnormal OCG and/or sonogram, OCG detected 47 (87%) while sonography detected 44 (81%). These small differences in detection rates were not statistically significant. On the basis of these results, we cannot conclude that either sonography or OCG has a diagnostic advantage in screening patients for gallbladder disease. The large numbers of false-negative examinations found on both sonography and OCG suggest that in a patient with persistent symptoms, the alternative study should be performed if the first examination is negative.

Progressive roentgenographic appearance of caustic esophagitis

We observed progressive roentgenographic changes in five patients who had caustic esophagitis after accidental ingestion of a liquid alkali. Initial endoscopic examination showed moderate caustic esophagitis in all patients, and esophageal atony and poor distension were early roentgenographic observations. Esophageal strictures developed 13 to 44 days after caustic ingestion in all patients. Intramural pseudodiverticula complicated stricture formation in two patients. Esophageal diverticula developed in two cases, three months to one year after caustic ingestion. In summary, moderate caustic esophagitis is associated with esophageal dilatation, atony, and peristaltic abnormalities initially, and with eventual stricture formation.

Radiologic evaluation of esophageal dysphagia

In patients with dysphagia, the radiographic examination evaluates both structural and functional abnormalities of the esophagus. Radiologic examination is more appropriate than endoscopy for initial screening of patients with dysphagia (Table 6). Endoscopy is more expensive, generally requires sedation, and is associated with a small but definite risk to the patient. Also, the endoscopic examination yields a poor evaluation of esophageal motor function and may fail to detect mucosal rings and peptic strictures, especially if smaller caliber instruments are used. The chief limitations of the radiographic examination are poor detection of mild cases of esophagitis and variable sensitivity and specificity in diagnosing esophageal motor disorders.

Cowden's disease: a case report and literature review

Cowden's disease, or multiple hamartoma syndrome, is an uncommon condition with characteristic mucocutaneous lesions associated with abnormalities of the breast, thyroid, and gastrointestinal tract. We describe a 51-year-old man with hyperplastic polyposis of the entire alimentary tract as the most prominent feature of this disease. We also present a review of 85 cases of this entity as reported in the English medical literature, and summarize the pertinent findings.

Natural progression of the lower esophageal mucosal ring

Among 390 patients with endoscopically verified lower esophageal mucosal ring (LEMR), 22 cases were identified with previous or subsequent radiologic examinations of the esophagogastric region. Among these, it was found that 2 cases of LEMR had developed from a normal esophagus. In 3 patients, there was increasing stenosis of the LEMR. In 8 cases, the LEMR was transformed into an esophageal stricture. In 10 of the 13 cases, esophagitis of varying degree was present endoscopically. In the 9 patients exhibiting no change in the LEMR, only 1 patient had esophagitis. The data suggest that there is a potential progression from normal esophagus to lower esophageal ring to esophageal stricture that occurs in association with reflux esophagitis.

Radiographic evaluation of esophagus immediately after pneumatic dilatation for achalasia

Forty-one (98%) of 42 patients with achalasia of the esophagus had pneumatic dilatation performed successfully using the Brown-McHardy dilator. One to four dilatations (mean, 1.9) were done on each patient with inflation pressures of 8-15 psi (mean, 11.1 psi). Immediately after the procedure, all patients were examined radiographically by injection of contrast material into the lower esophagus through a nasoesophageal tube. Two immediate and two delayed perforations occurred. Six intramural hematomas were noted, five of which resolved spontaneously. The luminal diameter at the esophagogastric junction increased from a mean of 4.2 mm before dilatation to 7.5 mm following treatment. Four patients with previous Heller myotomy were dilated without complications. Perforation was more common in patients with a minimal change in the esophagogastric diameter. Thirty-five patients (85%) improved symptomatically within several days following pneumatic dilatation. Excluding patients with perforation, the postdilatation appearance of the lower esophagus poorly correlated with clinical response.

Detection of colonic polyps on single-contrast barium enema study: emphasis on the elderly

A systems approach was employed to improve results of the single-contrast barium enema examination for detection of colonic polyps. Improvements were made in each of the following areas: radiographic-fluoroscopic equipment, fluoroscopic-television images, screen-film combinations, barium suspensions, examination techniques, imaging sequences, and quality controls. Radiologic-endoscopic correlation was undertaken for 137 colonic polyps seen endoscopically in 91 patients. The average age of the patients was 69 years. The sensitivity of the single-contrast examination for detection of all polyps was 80%. Polyps 5-9 mm in size were detected with 66% sensitivity, while 94% of polyps 10 mm or larger were detected. The results indicate that the sensitivity of a suitably performed single-contrast barium enema examination may approach that of the double-contrast study for the detection of colonic polyps, even in an elderly and infirm patient population.

Esophageal radiography and manometry: correlation in 172 patients with dysphagia

Radiographic and manometric examinations of the esophagus were correlated in 172 patients with dysphagia. Esophageal manometry was abnormal in 66 (38%), with diagnoses of nonspecific esophageal motor disorder (26), achalasia (19), nutcracker esophagus (12), diffuse esophageal spasm (seven), and scleroderma (two). Compared with manometry, radiographic sensitivities were 95% (18 of 19) for achalasia, 71% (five of seven) for diffuse esophageal spasm, and 46% (12 of 26) for nonspecific esophageal motor disorder. Nutcracker esophagus was not diagnosed specifically on the radiographic examination. Overall radiographic sensitivity was 56% (37 of 66) but increased to 89% by excluding nutcracker esophagus and nonspecific esophageal motor disorders. In 106 manometrically normal patients, radiographic specificity was 91% with 10 false-positive diagnoses of nonspecific motor disorder. We conclude that radiographic examination of the esophagus is useful in patients with dysphagia for evaluating functional esophageal abnormalities, although detection rates vary widely with the type of motor disorder.

Decreasing numbers of gastrointestinal studies: report of data from 69 radiologic practices

A survey of the members of the Society of Gastrointestinal Radiologists was conducted to document changes in the numbers of gastrointestinal fluoroscopic procedures performed in the United States from 1975 through 1986. Data from 69 radiologic practices indicated that the numbers declined substantially. Decreases in the numbers of upper gastrointestinal examinations, small bowel studies, and barium enemas was 24%, 17%, and 29%, respectively. The number of oral cholecystograms declined 93%. Respondents listed the advent of new techniques (sonography, CT, and MR imaging) and competition from endoscopy as the two major factors that they thought contributed to these decreases. They thought that competition from endoscopy would be the factor most likely to affect the numbers of gastrointestinal fluoroscopic procedures in the near future.

Recurrent colorectal carcinoma: evaluation with barium enema examination and CT

The efficacy of the barium enema examination and abdominal computed tomography (CT) was investigated in 81 patients who had undergone operation for colorectal carcinoma. Recurrent disease was found in 52 patients and was divided into local (anastomotic and perianastomotic) and remote (distant and hepatic metastases) types. In 32 patients with locally recurrent carcinoma, the sensitivity of the barium enema examination was 88%; for CT it was 69%. Conversely, the barium enema examination was not useful for detecting remote metastases shown on CT, which disclosed disease at one or more sites in 47 (90%) of the 52 patients. CT best evaluated recurrences remote from the anastomosis, pelvic recurrences in patients with colostomies, and hepatic metastases. Barium enema examination and CT were therefore found to be complementary modalities.

Multiphasic examinations of the stomach: efficacy of individual techniques and combinations of techniques in detecting 153 lesions

Multiphasic examinations of 153 gastric abnormalities observed radiologically and endoscopically were reviewed to determine the efficacy of four radiologic techniques and of several common combinations of these techniques for examining the stomach. There were 68 gastric ulcers, 12 ulcer scars, 44 cases of gastritis including 27 with erosions, 24 benign neoplasms, and five malignancies. Double-contrast, compression, mucosal relief, and full-column techniques detected 82%, 65%, 62%, and 51%, respectively, of all lesions diagnosed with the complete multiphasic examinations. Results indicate that the greater the number of techniques employed, the more accurate the examination, with biphasic and multiphasic examinations detecting 9%-18% more lesions overall than simple single- or double-contrast studies.

Pneumatic dilatation of the achalasic esophagus requiring the aid of an endoscope

We describe a 65-yr-old man with achalasia, who had two previous Heller myotomies. He had a markedly dilated, tortuous esophagus, which defeated initial attempts at pneumatic dilatation. A method was improvised in which a Brown-McHardy dilator was attached by a string to a small caliber endoscope and both were successfully passed into the stomach. Pneumatic dilatation was then easily performed. Review of the literature and our experience with four patients suggests that pneumatic dilatation can be performed without substantial risk in patients after a failed Heller myotomy.

Antral varices

Varices of the gastric fundus, often associated with esophageal varices, are a common complication of portal hypertension or splenic vein occlusion. However, varices of the gastric antrum have been reported rarely. We describe a 61-yr-old man with antral and esophageal varices caused by portal hypertension due to hepatic cirrhosis.

Radiological evaluation of dysphagia

Radiological examination evaluates both structural and functional abnormalities of the esophagus in patients with dysphagia. Combined with the clinical history, the radiological results can guide the clinician to a specific diagnosis, such as carcinoma or stricture, or to additional studies, such as endoscopy or esophageal manometry. Based on cost and diagnostic efficacy, the radiological method, compared with endoscopy, is most useful as the initial screening examination in patients with dysphagia (Table 2). Its major limitations are poor detection of mild cases of esophagitis and occasional lack of specificity in diagnosing esophageal motor dysfunction. To achieve these results, however, effective radiological evaluation of the esophagus requires the meticulous use of a combination of examining techniques.

Radiographic efficacy in gastric ulcer: comparison of single-contrast and multiphasic examinations

The efficacies of single-contrast and multiphasic examinations of the stomach for gastric ulcer detection were compared in 90 patients with 102 gastric ulcers, and in a control group of 382 patients without gastric ulcer. Single-contrast and multiphasic sensitivities were 62% and 64%, respectively. Radiographic detection depended significantly on ulcer size: Only 24% of ulcers under 5 mm were detected, compared with 89% of ulcers 5 mm or larger. Radiographic specificities and positive predictive values were similar for both types of examination. Moderate variation of the sensitivities and specificities of the three radiologists was observed, with ranges of 53-69% and 90-98%, respectively. Results indicated that gastric ulcer detection is more related to ulcer size and to individual interpretive variations than to the type of examination.

Radiologic and manometric correlation in "nutcracker esophagus"

"Nutcracker esophagus" is a newly described esophageal motor disorder seen in some patients with chest pain and/or dysphagia and characterized manometrically by normal primary peristalsis with distal contractions of high amplitude. The radiographic and manometric examinations in 20 patients with nutcracker esophagus were correlated. Normal primary peristalsis was observed radiographically in 16 patients, and a nonspecific motor disorder was diagnosed in the remaining four patients. Mild-to-severe nonspecific tertiary activity was seen in about half of the patients, esophageal wall thickness was normal. It is concluded that nutcracker esophagus is primarily a manometric diagnosis made in the appropriate clinical setting, and that the radiographic findings are normal or nonspecific.

Radiographic and endoscopic sensitivity in detecting lower esophageal mucosal ring

Radiographic and endoscopic sensitivities were compared in 60 patients with lower esophageal mucosal ring. Barium esophagram detected 57 (95%) rings, all shown by the prone full-column technique. Double-contrast technique in 39 patients demonstrated only 18 (46%) rings. Endoscopy detected 35 (58%) of 60 rings. Endoscopic sensitivity depended on ring caliber with detection of 18 (82%) of 22 rings 13 mm or less in caliber, 14 (54%) of 26 14-19 mm rings, and three (25%) of 12 rings 20 mm or wider. Dysphagia was present in 13 of 25 patients with rings undetected by endoscopy. The caliber of the fiberoptic instruments used also affected endoscopic detection, with 47% of the rings being diagnosed with narrower endoscopes and 76% being diagnosed with larger instruments. Thus, the radiographic examination was more accurate in detecting lower esophageal mucosal ring and should be used initially in patients with dysphagia and suspected lower esophageal narrowing.

Radiographic magnification of colon polyps

Radiographic magnification was evaluated on conventional and remote control machinery using a phantom with steel rods positioned at different levels. Depending on the rod-film distance, the range of magnification was 8-47% on remote control and conventional overhead films and 11-82% on conventional fluoroscopic spot-films. Extrapolation to the colon based on cross-sectional anatomic correlation showed a 14-27% variation in the radiographic magnification depending on the machinery used, the segment of the colon considered, and the position of the patient. This implies that substantial inaccuracy in the measurement of colonic polyps is common by barium enema examination, particularly when a conventional fluoroscope is used.