Normal Appendix


1. Kao SC, Smith WL, Abu-Yousef MM, et al. Acute appendicitis in children: sonographic findings. AJR 1989; 153:375-379.

2. Curtin KR, Fitzgerald SW, Nemcek AA, Hoff FL, Vogelzang RL. CT diagnosis of acute appendicitis: imaging findings. AJR 1995; 164:905-909.

Gallbladder and Biliary Tract

Sonographic Measurements of the Normal Pediatric Gallbladder and Biliary Tract

Normal Gallbladder Measurements vs. Age 1

Normal Sonographic Common Hepatic Duct Sizes vs. Age 1

1. McGahan JP, Phillips HE, Cox KL. Sonography of the normal pediatric gallbladder and biliary tract. Radiology 1982; 144(4): 873-875. Tables modified and used with permission for this Website.

GI Tract

Normal GI Tract: Wall Thickness on CT


  1. Desai RK, Tagliabue JR, Wegryn SA, Einstein DM. CT evaluation of wall thickening in the the alimentary tract. Radiographics 1991;11:771-783.

  2. Fisher JK. Abnormal colonic wall thickening on computed tomography. J comput assist tomogr 1983; 7: 90-97.

  3. In Siegel MJ. Pediatric Body CT. Lippincott Williams & Wilkins: Philadelphia. 1999. pp 204, 207, 219.

Lymph Nodes on CT

Normal Abdominal Lymph Nodes in Adolescents and Adults:CT¹


  1. Dorfman RE, Alpern MB, Gross BH, Sandler MA. Upper abdominal lymph nodes:criteria for normal size determined with CT. Radiology1991; 180:319-322. Table modified and used with permission for this Website.

  2. Newman B, Arcement CM, Siegel MJ. CT and MR imaging of mediastinal masses in children. Current Concepts in Body Imaging at the Millenium. RSNA Syllabus 1999

Pancreas & Pancreatic Duct

Normal Pancreas Size as a Function of Age (Ultrasound)*¹

*Measured as maximum AP on transverse scan

The normal pancreatic duct is less than 2 mm in diameter

Computed Tomography: The craniocaudal dimension of the head ranges from 2 to 6 cm, while the body and tail ranges from 2 to 4 cm.2


  1. Siegel MJ, Martin KW, Worthington JL. Normal and abnormal pancreas in children: US studies. Radiology 1987; 165:15-18. Table 1 used with permission.

  2. Siegel MJ. Pediatric Body CT. Lippincott Williams & Wilkins: Philadelphia. 1999. p 263.

Portal Vein

Normal Main Portal Vein Size on Ultrasound as a Function of Age


<10 years

10 to 20 years

Main Portal Vein Transverse Diameter (mm)

8.5 ± 2.7

10 ± 2


  1. Patriquin HB, Perreault G, Grignon A, et al. Normal portal venous diameter in children. Pediatric Radiol 1990; 20: 451-453.

  2. Weinreb J, Kumari S, Phillips G, Pochaczevsky R. Portal vein measurements by real-time sonography. AJR 1982; 139(3):497-499. In source: Siegel MJ. Pediatric Sonography. Raven Press: New York. 1995 . p 175.


Muscle thickness < 3.0 mm Pyloric channel length < 17mm

Muscle wall thickness: measured as a single hypoechoic layer between serosa and echogenic submucosa. (muscle thickness exaggerated for illustration)

NOTE: PRETERM INFANTS. Borderline muscle thickness measurements are more likely to occur in premature infants than in term infants. In preterm infants, the thickness of the pyloric muscle relative to the rest of the stomach and the pyloric canal length is more important than the absolute muscle thickness.


  1. Blumhagen JD, Maclin L, Krauter D, Rosenbaum DM, Weinberger E. Sonographic diagnosis of hypertophic pyloric stenosis. AJR 1988; 150:1367-1370.

  2. Blumhagen JD, Weinberger E. Pediatric gastrointestinal ultrasounography. In : Ultrasound annual. New York: Raven Press; 1986; 99-140.

  3. O'Keefe FN, Stansberry SD, Swischuk LE, Hayden CK Jr. Antropyloric muscle thickness at US in infants: what is normal? Radiology 1991; 178: 827-830.

  4. Rollins MD, Shields MD, Quinn RJM, et al. Pyloric stenosis: congential or acquired? Arch Dis Child 1989; 64:138-147.


Ultrasound: Normal Spleen Size vs. Age¹

*Measurement obtained in the coronal longitudinal plane


  1. Rosenberg HK, Markowitz RI, Kolbeg H, et al. Normal splenic size in infants and children: sonographic measurements. AJR 1991; 157:119-121. Table modified and used with permission.