US Quick Ref

Ref values

Reference Range
KUB
Urinary Bladder (wall)
  • < 0.8 cm (Collapse)
  • < 0.4 cm (Distend)
Residual Urine

< 100 ml
Repro
Uterus
  • Size < 5 x 4 x 8 cm (AP x TV x Long)
  • ETT
    • < 1.5 cm
    • < 0.5 cm (post-menstrual)
Prostate
  • < 25 ml (Normal)
  • 25 - 40 ml (Prominent)
  • > 40 ml (BPH)
HBP
Liver

Span 15 - 17 cm (sagital, at MCL)
Gallbladder
  • Long = 9 - 11 cm
  • TV < 4 cm
  • Wall thickness < 3 mm
CBD
  • < 0.6 cm (< 0.9 for post-cholecystectomy)
  • Age > 60 yrs can dilate 0.1 cm / 10 yrs
Pancreas
  • Main pancreatic duct diameter < 3 mm.
Vessel
Veins
  • Splenic v. < 11 mm
  • SMV < 12 mm
  • Portal v. < 13 mm
Aorta

Normal

  • < 2.5 cm (Upper)
  • < 2 cm (Lower)

Abnormal

  • 2.5 - 3 cm (Ectasia)
  • > 3 cm (Aneurysm)
Kidneys

Normal

  • Long < 10 - 12 cm
  • Cortical thickness > 1 cm

Abnormal

  • Long < 8 cm (kidney disease)
Spleen
  • < 12 cm (Normal)
  • 12 - 15 cm (Mild splenomegaly)
  • > 15 cm (Mark splenomegaly)
Thyroid
  • Size < 3 x 2 x 6 cm ?? (AP x TV x Long)
  • Cervical LN
    • minimal axial diameter < 1 cm
    • oval shape (axis–to–long axis ratio [S/L] < 0.5)
AP = Anteroposterior, TV = Transverse, Long = Longitudinal

Reference

  • Mainly from [1].

Ellipsoid volume

Approximated formular:

\[ 0.5 \times D_1 \times D_2 \times D_3 \tag{1}\]

Equation 1, where \(D_1\), \(D_2\), \(D_3\) are diameter along 3 perpendicular axis.

Full formular:

\[ \frac{4}{3} \pi \times r_1 \times r_2 \times r_3 \tag{2}\]

Equation 2, where \(r_1\), \(r_2\), \(r_3\) are radius along 3 perpendicular axis.

(ref: ellipsoid-calc)

References

[1]
B. Block, Abdominal ultrasound: Step by step, 3rd edition, Thieme, Stuttgart New York Delhi Rio de Janeiro, 2016.