Advertisment
Indian Journal of Nephrology About us |  Subscription |  e-Alerts  | Feedback | Login   
  Print this page Email this page   Small font sizeDefault font sizeIncrease font size
 Home | Current Issue | Archives| Ahead of print | Search |Instructions |  Editorial Board  

Users Online:1093

Official publication of the Indian Society of Nephrology
  Search
 
  
 ~  Similar in PUBMED
 ~  Search Pubmed for
 ~  Search in Google Scholar for
 ~  Article in PDF (424 KB)
 ~  Citation Manager
 ~  Access Statistics
 ~  Reader Comments
 ~  Email Alert *
 ~  Add to My List *
* Registration required (free)  

 
   References
   Article Figures

 Article Access Statistics
    Viewed2847    
    Printed30    
    Emailed0    
    PDF Downloaded107    
    Comments [Add]    

Recommend this journal

 


 
  Table of Contents  
IMAGES IN NEPHROLOGY
Year : 2016  |  Volume : 26  |  Issue : 3  |  Page : 223-224
 

Dense renal medulla sign


Department of Radiology and Interventional Radiology, Institute of Liver and Biliary Sciences, New Delhi, India

Date of Web Publication27-Apr-2016

Correspondence Address:
B Sureka
Department of Radiology and Interventional Radiology, Institute of Liver and Biliary Sciences, New Delhi - 110 070
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0971-4065.159554

Rights and Permissions



How to cite this article:
Sureka B, Bansal K, Arora A. Dense renal medulla sign. Indian J Nephrol 2016;26:223-4

How to cite this URL:
Sureka B, Bansal K, Arora A. Dense renal medulla sign. Indian J Nephrol [serial online] 2016 [cited 2020 Apr 4];26:223-4. Available from: http://www.indianjnephrol.org/text.asp?2016/26/3/223/159554




A 50-year-old male, a known case of chronic liver disease, presented to us with abdominal distension for 2 days. Contrast-enhanced computed tomography (CT) scan revealed decompensated cirrhosis with portal hypertension. Clinically, the patient had features of dehydration. Plain CT sections revealed medullary regions of the kidney to be brighter than the cortex showing“dense renal medulla” sign (DRM) [Figure 1]. No calculus was seen in kidneys, ureter or in the urinary bladder. Urine examination revealed increased osmolality (970 mOsm/kg of water) and increased urine-specific gravity (1.037). The renal function tests were normal.
Figure 1: (a) Coronal reformatted NCCT image showing hyperdense renal pyramids in right kidney (b) same patient oblique coronal reformatted image of left kidney in profile view showing hyperdense renal pyramids

Click here to view


Dense renal medulla is defined as increased attenuation of the medulla as compared to the renal cortex on plain CT scan.[1] It can be further divided into focal (confined to medullary tip) or global (involving entire medulla). Our case had global dense renal medullary involvement. DRM sign is also known as white pyramid sign or hyperdense renal pyramids sign. It is seen in conditions that increase urine osmolality (dehydration, hypernatremia, high-protein diet, glycosuria, adrenal insufficiency, and syndrome of inappropriate secretion of antidiuretic hormone), acute ureteric obstruction, high-dose antibiotic therapy due to antibiotic precipitation in collecting tubules, high caffeine intake, hyperparathyroidism, medullary sponge kidneys, medullary cystic disease, renal tuberculosis, sickle cell disease, renal papillary necrosis, and hyperuricemia.[2] Bilateral high-attenuation renal pyramids can occasionally be seen as an incidental finding. The presence of high-attenuation renal pyramids in only one kidney may suggest obstruction in the contralateral kidney.[3]

The most important differential diagnosis is medullary nephrocalcinosis. It is characterized by deposition of calcium salts in the medulla of the kidney. Serum and urinary calcium levels may be abnormal in these cases. Calcium salts which are deposited in medullary nephrocalcinosis mimic calcified concretions and reveal echogenic medullary pyramids on ultrasonography vis-á-vis DRM, which shows subtle hyperdensity as in this case. Ultrasonography is usually normal in cases of DRM. The disappearance of this hyperdensity following adequate hydration clinches the diagnosis. The index case had normal serum and urinary calcium levels, was dehydrated at the time of presentation, and renal ultrasound did not reveal echogenic medullary pyramids. Thus, dense renal pyramids in our case may be due to a combination of dehydration and high-protein diet advised in cirrhotic patients. We would like to conclude that dense renal pyramids should not be misinterpreted as medullary nephrocalcinosis by the radiologists and clinicians should be aware of this intriguing entity.

 
  References Top

1.
Tublin ME, Tessler FN, McCauley TR, Kesack CD. Effect of hydration status on renal medulla attenuation on unenhanced CT scans. AJR Am J Roentgenol 1997;168:257-9.  Back to cited text no. 1
    
2.
Starinsky R, Barr J, Lushkov G, Segal M, Manor A, Golik A. CT of renal densities caused by intravenous infusion of antibiotics. J Comput Assist Tomogr 1995;19:228-31.  Back to cited text no. 2
    
3.
Dalrymple NC, Casford B, Raiken DP, Elsass KD, Pagan RA. Pearls and pitfalls in the diagnosis of ureterolithiasis with unenhanced helical CT. Radiographics 2000;20:439-47.  Back to cited text no. 3
    


    Figures

  [Figure 1]



 

Top
Print this article  Email this article
 

    

Indian Journal of Nephrology
Published by Wolters Kluwer - Medknow
Online since 20th Sept '07