title: [Exactness of transcutaneous sonography in the diagnosis of gastric wall lesions].
abstract: OBJECTIVE
  Our objective was to determine sensitivity, especificity and predictive values of transcutaneous sonography for detecting gastric wall lesions.
  
  
  METHODS
  This prospective study was performed from March 1999 to April 2000 on 150 patients referred for transcutaneous sonography by the Endoscopic Service Unit. Sonographic examinations were performed using RT 4000 General Electric equipment with 5 Mhz transducer and replenishment of stomach with fluid. All scanning was done by the same sonographer, who was unaware of endoscopic, tomographic, or upper gastrointestinal series features. Results from sonography were compared with gastrointestinal tract endoscopy. Sensitivity, specificity, and predictive values were determined using contingency statistical procedure. Sonographic examination accuracy was calculated evaluating sensitivity and specificity confidence intervals (CI). Kappa index was calculated. Diagnostic accuracy differences observed between tumoral and non-tumoral lesions by sonography were evaluated by chi 2 probe.
  
  
  RESULTS
  Sensitivity of 85% (95% CI, from 75.2 to 94.8%) and specificity of 90% (95% CI, from 86 to 93.9%) were obtained. Positive predictability was 78% and negative predictability was 94%. Diagnostic accuracy was 87%. Kappa index was 0.717. There were 35 no false-positive results (19 tumoral lesions and 16 non-tumoral lesions), seven false-negative results (one tumoral lesion and six non-tumoral lesions) and 10 false-positive results (two tumoral lesions and eight non-tumoral lesions). Only one of 20 tumoral lesions were diagnosed by ultrasound whereas from 22 non-tumoral lesions were not diagnosed 6 (chi 2 = 3.74, p > 0.05).
  
  
  CONCLUSIONS
  Transcutaneous sonography is a rapid, low cost and non-invasive method that may be useful to establish clinic diagnosis and in the first steps of gastric wall lesions evaluation, it is valuable in assessment of diagnostic orientation for the referring clinic.
authors.affiliation: Departamento de Radiología e Imagen, Hospital de Especialidades No. 14 del Centro Médico Nacional Adolfo Ruiz Cortines, Instituto Mexicano del Seguro Social, 91980 Veracruz, Ver. quimoro@hotmail.com
authors.forename: Rocío
authors.initials: R
authors.lastname: Quiroz Moreno
authors.forename: Margarita Isabel
authors.initials: MI
authors.lastname: Morales Guzmán
authors.forename: Juan A
authors.initials: JA
authors.lastname: Cervantes Monroy
authors.forename: Guillermo
authors.initials: G
authors.lastname: Rueda Torre
authors.forename: Leticia
authors.initials: L
authors.lastname: Díaz Caldelas
mesh_terms: D000005:Abdomen / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005773:Gastroscopy; D006801:Humans; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013270:Stomach / Q000000981:diagnostic imaging; D013272:Stomach Diseases / Q000000981:diagnostic imaging*; D014463:Ultrasonography