Normal reference values

A list of normal radiological reference values is as follows:

  1. adrenal gland: <1 cm thick, 4-6 cm length
  2. aorta: <3 cm diameter
  3. appendix: on CT <6 mm calibre
  4. atlantodental distance
    • adults: <3 mm
    • children: <5 mm
  5. azygous vein: on erect chest x-ray < 10 mm diameter
  6. bladder wall: <3 mm (well distended state)
  7. boehler's angle: 20-40o
  8. capitolunate angle: <30o
  9. carinal angle: <60-70o
  10. colon:
    • lumen: <5 cm
    • wall: <3 mm
  11. common bile duct
    • <7 mm and add 1 mm for each decade over age of 60 years
    • up to 10 mm post cholecystectomy
  12. diaphragm (right dome is usually higher than left)
    • difference between right and left: <3 cm
  13. endometrial thickness
    • pre-menopausal: 3-15 mm
    • post-menopausal: <6 mm
  14. esophagus wall: <3 mm (with distended lumen)
  15. gallbladder wall: <3 mm (well distended)
  16. heart (cardiothoracic ratio): <55%
  17. inferior vena cava: <28 mm
  18. internal carotid artery:
    • PSV: <125 cm/s
    • EDV: <40 cm/s
  19. kidneys : 8-10 cm x 4-6 cm
  20. liver span: <15 cm
  21. lymph nodes
    • mediastinal: <10mm in short axis
    • retro-crural: <6mm in diameter
  22. ovarian follicle: <2.5-3 cm
  23. ovaries: volume
    • pre-menopausal: <18 cc
    • post-menopausal: <8 cc
  24. paraspinal lines:
  25. paratracheal stripe: <5 mm
  26. pancreatic duct
    1. head: 3.5 mm
    2. body: 2.5 mm
    3. tail: 1.5 mm
  27. portal vein: <13 mm diameter
  28. prevertebral soft tissue thickness (lateral c-spine x-ray):
    • 7 mm at C2
    • 2 cm at C7
    • easiest way to remember is "7 at 2 and 2 at 7" 
  29. prostate volume: <25 - 30 cc
  30. pulmonary artery
    • descending branch of right pulmonary artery: <16 mm (males), <15 mm (females)
    • main pulmonary artery: <29 mm
  31. rectum: wall thickness <5 mm
  32. scapholunate angle: 30-60o
  33. small bowel
    • lumen: <3 cm
    • wall: <3 mm
  34. spleen: <12 cm
  35. splenic vein: <10 mm diameter
  36. testis
    • vein: <2 mm diameter
    • size: <5 x 3 x 3 cms (volume: 12.5-19 cc)
  37. thyroid: <2 cm anteroposterior dimension
  38. trachea
    • chest x-ray: <25 mm (males) , <21 mm (females)
  39. ureter: 30-34 cm long, 2-8 mm diameter
  40. uterus
    • prebuscent: length up to 3 cm, diameter around 1 cm
    • nulliparous: length up to 8 cm, diameter around 8 cm
    • multiparous: length up to 9.5 cm, diameter around 5.5c m
    • postmenopausal: length up to 6 cm, diameter around 2 cm
  41. uterine cervix: diameter less than 3 cm

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Article Information

rID: 25700
Section: Gamuts
Synonyms or Alternate Spellings:
  • Normal reference values in radiology
  • Normal anatomical reference values in radiology
  • Normal anatomical reference values

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