Description of the technique of upper gastrointestinal series radiological examination for the evaluation of the esophagus, stomach and duodenum of Wistar female rats.

Purpose: To evaluate the anatomy of female Wistar rats and the workability of contrast radiography as a technique to investigate the gastrointestinal series.

Methods: Eight adult female Wistar rats were undergone to the contrast radiography as anteroposterior incidence and as posterior incidence in profile. The radiological examination was conducted at a 45 degrees angle to the radiological table. Film-focus distance (FFD) was 100 cm, film-object distance (FOD) was 0 cm, and object-focus distance (OFD) was 100 cm. An orogastric probe was used to inject barium contrast at 5-min intervals, for a total of four applications. After the radiological examination, animals were necropsy for confirmation of the radiological findings, and the radiographs were the absence of the normal anatomy variations inspected and described by an experienced radiologist.

Results: All the radiographs produced achieved satisfactory results in terms of position, exposure, location and quality. The upper esophageal sphincter (UES) was identified in the esophagus at the nerve C2, the lower esophageal sphincter (LES) was identified between spinal cord segments L1 and L2, the thoracic-abdominal junction was observed at T10, the esophageal-gastric junction (EGJ) at T13-L1, with the abdominal portion in the epigastric region. The stomach was observed mostly in the epigastric region, left hypochondrium, left and mesogastric flank. The duodenum findings presented higher variation, with most findings identified in the epigastric region, right hypochondrium, right flank and mesogastric ileal fossa at T13-L5.

Conclusion: Contrast radiology is useful and may be employed to assess the anatomy of the animal being studied. The experimental model described afforded to fully identify all organs investigated, as well as other occasional relevant findings. No anatomical anomalies in the subsequent necropsy, confirming the radiographic findings.