Andrew Timothy Trout MD, Presenter: Nothing to Disclose

Alex Towbin MD, Abstract Co-Author: Author, Amirsys Inc. Shareholder, Merge Healthcare Incorporated

Bin Zhang PhD, Abstract Co-Author: Nothing to Disclose

Marguerite Care MD, Abstract Co-Author: Nothing to Disclose

The purpose of this study is to describe the “striated MR nephrogram” (Fig), an appearance that can be seen on delayed, post-contrast MRI, and to determine its frequency and identify potential causative factors.

After IRB approval, 3 pediatric radiologists retrospectively reviewed delayed post-contrast spinal MR exams performed in children between Jan 1, 2006 and July 1, 2012. The following variables were recorded: presence of low signal renal striations; presence of gadolinium in the bladder; aortic and inferior vena caval diameters; timing of the contrast administration in relation to imaging; and the scanner on which the exam was performed. Charts were reviewed for patient demographics and clinical information relevant to renal function including: renal function lab results, GFR (calculated and determined by scintigraphy), and history of renal disease.

Striations were observed in one or both kidneys in 117 of 912 cases (12.8%). There was a significant association between the presence of striations and the specific scanner on which the exam was performed (p=0.001) though this was not related to field strength (1.5T vs. 3T). Other significant predictors of the presence of a striated nephrogram included: aortic diameter (Y

The “striated MR nephrogram” is an uncommon, but not infrequent, phenomenon on delayed post-contrast images. This phenomenon is likely caused by concentrated gadolinium within the collecting ducts. While there is a statistically significant association between the presence of striations and several variables, the cause of the observed phenomenon in only select patients is unclear and does not appear to reflect poor renal function, timing or hydration status. The radiologist should be aware that the “striated MR nephrogram” may be present on delayed post-contrast images, and it should not be mistaken for a pathologic process.

A striated appearance of the kidney may be observed in 12.8% of delayed post-contrast MR images. This presumably relates to concentrated gadolinium and does not represent pathology.

Trout, A, Towbin, A, Zhang, B, Care, M, The “Striated MR Nephrogram”: An Infrequent Finding on Delayed Post-contrast Images of the Kidneys.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13044395.html