title: Differentiation of achalasia from pseudoachalasia by computed tomography.
abstract: OBJECTIVE
  The purpose of this study was to determine the computed tomography (CT) findings in idiopathic achalasia and in the pseudoachalasia of malignancy.
  
  
  METHODS
  We identified 12 patients with the manometric diagnosis of achalasia who also had CT scans available for review: eight had idiopathic achalasia, and four had pseudoachalasia. As controls, we selected nine patients with endoscopically obvious esophageal cancer who also had CT scans. The CT scans were blindly reviewed to determine esophageal wall thickness, symmetry of the esophageal wall, presence of esophageal dilation or mass, and a radiological diagnosis.
  
  
  RESULTS
  Six of the eight patients with achalasia had a dilated esophagus. Five had symmetric wall thickening >5 mm (range 7-10 mm) at the gastroesophageal junction. One patient with a 10-mm wall thickening was incorrectly diagnosed with a mass. All others were correctly diagnosed with achalasia. Three of the four patients with pseudoachalasia had esophageal dilation. Two had an obvious esophageal mass. The other two were given an indefinite diagnosis: one had asymmetric wall thickening (11 mm) at the gastroesophageal junction, and the other had symmetric thickening of 18 mm. Eight of the nine patients with obvious esophageal cancer had a mass on CT; the other patient had asymmetric wall thickening of 6 mm at the gastroesophageal junction and was given an indefinite diagnosis.
  
  
  CONCLUSIONS
  Most achalasia patients have CT findings of esophageal dilation and mild, symmetric wall thickening. Therefore, symmetric esophageal wall thickening (<10 mm) should not dissuade one from the diagnosis of achalasia. Most pseudoachalasia patients have CT findings of esophageal dilation, more marked and/or asymmetric wall thickening, or mass. In this group, asymmetric or marked thickening (>10 mm) indicated pseudoachalasia. Therefore, CT can be helpful in differentiating between achalasia and the pseudoachalasia of malignancy.
authors.affiliation: Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520-8019, USA.
authors.forename: M
authors.initials: M
authors.lastname: Carter
authors.forename: R C
authors.initials: RC
authors.lastname: Deckmann
authors.forename: R C
authors.initials: RC
authors.lastname: Smith
authors.forename: M I
authors.initials: MI
authors.lastname: Burrell
authors.forename: M
authors.initials: M
authors.lastname: Traube
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D004931:Esophageal Achalasia / Q000000981:diagnostic imaging*; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging; D004947:Esophagus / Q000000981:diagnostic imaging; D006801:Humans; D008875:Middle Aged; D011230:Precancerous Conditions / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000706:statistics & numerical data