Normograms of abdomen and gastrointestinal tract



7.3: Normograms of abdomen and gastrointestinal tract


Eesha Rajput, Gurdarshdeep Singh Madan, Vineet Wadhwa



Oesophagus





  • • Oesophagus is a fibromuscular tube that extends from crico-pharynx to gastro-oesophagal (GE) junction. It is divided into four parts according to the AJCC classification system (Fig. 7.3.1). These parts are well seen on coronal images of CT.


    • • Cervical oesophagus
    • • Thoracic oesophagus
    • • Abdominal oesophagus





















Anatomical name Anatomical Extension
Cervical Hypopharynx to sternal notch
Thoracic-upper Sternal notch to azygos vein
Thoracic-middle Lower border of azygos vein to inferior pulmonary vein
Thoracic-lower Lower border of inferior pulmonary vein to EGJ
Abdominal EGJ to 2 cm below EGJ

EGJ, esophagogastric junction.




  • • Normal oesophageal features on barium studies


    • • In most patients, normal mucosal surface is smooth and featureless.
    • • Normal longitudinal folds are seen in partially collapsed oesophagus – measuring 1–3 mm in thickness.
    • • Occasionally transverse folds may be seen in normal patients.
    • • At the junction of smooth and striated muscle in midthoracic oesophagus (at the level of aortic arch) – spiculated transverse fold may be seen and is a normal finding.
    • • Normal external impression on oesophagus


      • • Aortic arch
      • • Left main bronchus
      • • Heart

    • • Oesophageal rings and Oesophageal vestibule (Fig. 7.3.2)


      • • A ring/Wolf ring –


        • • It is the muscular contraction at the junction of tubular oesophagus and vestibule.


          • • It has no definite anatomic correlate.

      • • B ring –





          • • It is normally seen located at squamocolumnar junction (Z line). The appearance does not change during the examination.
          • • Significance:

        • • If the B ring is >20 mm wide, no obstruction occurs.

      • • If the B ring is 13–20 mm wide, it may cause episodic dysphagia, and is then called a SCHATZKI RING.
      • • Between the A and the B rings the distal oesophagus enlarges and becomes fusiform – known as phrenic ampulla or oesophageal vestibule.

  • • Diameter of the oesophagus (Fig. 7.3.3).


    • • Measured on axial CT images.
    • • Diameter up to 15 mm is considered normal.
    • • Any measurement 20 mm or more is abnormal.

  • • Upper oesophageal sphincter (Fig. 7.3.4).


    • • It is noted on barium meal study.
    • • Located at C5–C6 level.
    • • Formed by cricopharyngeus muscle.

  • • Lower oesophageal sphincter (Fig. 7.3.5).


    • • It is noted on barium swallow study.
    • • Bulbous distension of distal 2–4 cm of lower oesophagus is called vestibule and corresponds to the manometrically defined high-pressure zone that constitutes the lower oesophageal sphincter.
    • • It is best demonstrated by breath-holding in inspiration or Valsalva manoeuvre.

  • • Sliding hiatus hernia (Fig. 7.3.6).


    • • Seen on barium meal.
    • • It accounts for >95% cases of hiatus hernias.
    • • It is defined as GE junction located >2 cm above the oesophageal hiatus in the diaphragm.

  • • Tracheo-oesophageal (TE) stripe (Fig. 7.3.7).


    • • Noted on lateral chest radiograph.
    • • TE stripe is the width of juxtaposed posterior tracheal and anterior oesophageal wall.
    • • Normal width ≤5 mm.
    • • If TE stripe is >5 mm, it indicates oesophageal pathology like oesophageal carcinoma or achalasia.

Image
Fig. 7.3.1 Divisions of the oesophagus.

Image
Fig. 7.3.2 Oesophageal rings.

Image
Fig. 7.3.3 Measuring diameter of the oesophagus on axial CT image.

Image
Fig. 7.3.4 Upper oesophageal sphincter on barium swallow.

Image
Fig. 7.3.5 Lower oesophageal sphincter on barium swallow.

Image
Fig. 7.3.6 Hiatus hernia.

Image
Fig. 7.3.7 Lateral chest radiograph showing trachea-oesophageal stripe.

Stomach





  • • Stomach is the muscular organ that lies between oesophagus and duodenum in upper abdomen. It starts from GE junction at the level of diaphragm D10.
  • • Normal volume of stomach


    • • Adults: 45 mL (volume of empty stomach)
    • • Adults (maximum volume): 2–4 L
    • • Newborn baby: 30 mL

  • • Gastric wall thickness


    • • Measures on CECT with distended stomach using positive oral contrast
    • • Antrum – 5–7 mm
    • • Body – 2–3 mm

  • • Bariatric surgery (Fig. 7.3.8).


    • • In bariatric surgery called gastric banding, an adjustable band is placed approximately 2 cm below the GE junction.
    • • The angle of the band relative to the spine (Phi angle) is normally 4–58 degrees.
    • • Anterior and posterior aspects of the band should be superimposed.
    • • Indicators of slippage of the band are:


      • • Symptoms of obstruction
      • • Angle of the band relative to the spine >60 degrees or obtuse.

  • • Hypertrophic pyloric stenosis (Fig. 7.3.9).


    • • Refers to idiopathic thickening of gastric pyloric musculature which then results in progressive gastric outlet obstruction.
    • • Seen in newborn babies as early as 3 weeks.
    • • Measurements are made of thickened hypoechoic pylorus on ultrasound (US). Gallbladder is identified on US and probe is turned obliquely sagittal to the body to visualize the pylorus.
    • • Measurements s/o Hypertrophic pyloric stenosis are:


      • • Pyloric muscle thickness >3 mm
      • • Length of thickened segment >15–17 mm
      • • Pyloric volume >1.5 cm3
      • • Pyloric transverse diameter >13 mm

  • • Retrogastric and retroduodenal spaces

Tags:
Mar 15, 2026 | Posted by in OBSTETRICS & GYNAECOLOGY IMAGING | Comments Off on Normograms of abdomen and gastrointestinal tract

Full access? Get Clinical Tree
Get Clinical Tree app for offline access