Medical Specialty >> Urology

Doctors Lounge - Urology Answers

Back to Urology Answers List

If you think you may have a medical emergency, call your doctor or 911 immediately. Doctors Lounge ( does not recommend or endorse any specific tests, physicians, products, procedures, opinions, or other information that may be mentioned on the Site.

DISCLAIMER: The information provided on is designed to support, not replace, the relationship that exists between a patient/site visitor and his/her physician. Please read our 'Terms and Conditions of Use' carefully before using this site.

Date of last update: 8/13/2017.

Forum Name: Urology Topics

Question: What is the size of the renal pelvis?

 l00d2f - Sat Oct 24, 2009 2:39 pm

What is the size of the renal pelvis? I have a 1.6 cm dense stone per CT on 10/21. "Dense stone within the right collecting system 1.6 cm in the renal pelvis and a 2nd stone 1.1 cm in the mid kindey medially." I have had large stones before, but always in the kidney itself. The largest was 2.5 cm by 4.5 cm. It took 10 hours of surgery over 3 days to remove. Is the one in the renal pelvis different than one inside the kidney?
 Dr.M.Aroon kamath - Sun Oct 25, 2009 7:26 pm

User avatar Hi,
The size of the renal pelvis is variable, depending on age, anatomical variations. obstructed vs non-obstructed and individual variations.
There are 2 kinds of renal pelvis which are important for a surgeon, especially if open surgery is contemplated.
One is an intra-renal pelvis (the pelvis is almost completely within the kidney)and the other is an extra-renal pelvis (the pelvis is almost completely outside the kidney).
The intra-renal pelvis can make 'open' stone removal (nephrolithotomy/pyelolithotomy) technically demanding and time-consuming.
I hope this information is of use to you!
 l00d2f - Mon Oct 26, 2009 10:51 am

Is there a way from my ct to tell if the large dense stone is intra-renal pelvis or an extra-renal pelvis one? Since the stone is large can it affect the kindey's ability to empty into the bladder? Thank you.
 Dr.M.Aroon kamath - Mon Oct 26, 2009 6:53 pm

User avatar Hi,
Your radiologist will be certainly be glad to let you have that information.I think it is quite possible to to tell that from the CT. A large stone in the renal pelvis is certainly capable of blocking the flow of urine down the ureter.Best wishes.

| Check a doctor's response to similar questions

Are you a Doctor, Pharmacist, PA or a Nurse?

Join the Doctors Lounge online medical community

  • Editorial activities: Publish, peer review, edit online articles.

  • Ask a Doctor Teams: Respond to patient questions and discuss challenging presentations with other members.

Doctors Lounge Membership Application

Tools & Services: Follow DoctorsLounge on Twitter Follow us on Twitter | RSS News | Newsletter | Contact us