Striated Nephrogram Due to Hypotension

50-year-old male in a motor vehicle collision (MVC) presenting with hypotension. What is the diagnosis? • Xray of the Week

Figure 1. Abdominal CT. Name the significant findings.

Figure 2. A) Axial CT - bilateral striated nephrogram (red arrows). B) Axial CT - retroperitoneal hematoma (yellow arrows). C) Coronal CT – bilateral striated nephrogram (red arrows).

Discussion:

As a result of trauma this patient is hypotensive due to a large retroperitoneal hematoma which is partially visualized on these images. Patients with blunt trauma who are hypotensive and tachycardic are deemed to be in hemorrhagic shock until proven otherwise [1].

A striated nephrogram refers to a mixture of alternating low-attenuating and normal-enhancing bands within the kidney arranged radially on CT [2]. The pattern is due to any process that causes inflammation or edema in the renal cortex or medulla [3]. Striated nephrograms can be unilateral or bilateral, depending on the underlying pathology. Common causes of unilateral striated nephrogram include ureteric obstruction, acute pyelonephritis, renal contusion, and renal vein thrombosis. Bilateral striated nephrogram can be seen with hypotension, autosomal recessive polycystic kidney disease, acute pyelonephritis, and acute tubular necrosis [2,4].

Retroperitoneal hematoma is frequently due to traumatic vascular injury but can be associated with ruptured aortic aneurysm, coagulopathy, or iatrogenesis [5]. Hypotension is the principal finding; yet some patients may present with abdominal tenderness, distension and/or flank pain. CT is the imaging modality of choice if retroperitoneal hematoma is suspected clinically [5]. Acute and subacute hematomas have high attenuation on CT whereas chronic hematomas are often low in attenuation [6]. Treatment is dependent on the cause of the hematoma and patient condition with supportive care including blood transfusion, reversal of any coagulopathy, and observation for stable patients. Angiography with embolization or rarely surgery may be required for unstable patients [5].

References:

1. Barkin AZ, Fischer CM, Berkman MR, Rosen CL. Blunt abdominal trauma and a diaphragmatic injury. J Emerg Med. 2007;32(1):113-117. doi:10.1016/j.jemermed.2006.11.001

2. Wolin EA, Hartman DS, Olson JR. Nephrographic and pyelographic analysis of CT urography: differential diagnosis. AJR Am J Roentgenol. 2013;200(6):1197-1203. doi:10.2214/AJR.12.9692

3. Moinuddin I, Bracamonte E, Thajudeen B, Sussman A, Madhrira M, Costello J. Allergic Interstitial Nephritis Manifesting as a Striated Nephrogram. Case Rep Med. 2015;2015:250530. PMCID: PMC4667022 doi:10.1155/2015/250530

4. Saunders HS, Dyer RB, Shifrin RY, Scharling ES, Bechtold RE, Zagoria RJ. The CT nephrogram: implications for evaluation of urinary tract disease. Radiographics. 1995;15(5):1069-1088. doi:10.1148/radiographics.15.5.7501851

5. Mondie C, Maguire NJ, Rentea RM. Retroperitoneal Hematoma. [Updated 2020 Nov 12]. In: StatPearls https://www.ncbi.nlm.nih.gov/books/NBK558928/

6. Rajiah P, Sinha R, Cuevas C, Dubinsky TJ, Bush WH Jr, Kolokythas O. Imaging of uncommon retroperitoneal masses. Radiographics. 2011;31(4):949-976. doi:10.1148/rg.314095132

Deven Champaneri is a medical student at Edward Via College Osteopathic Medicine (VCOM) – Carolinas and plans to pursue residency in diagnostic radiology. While he was rotating through various specialties, he realized his passion for DR and valued its role in all aspects of medicine. He graduated from the University of South Carolina in 2017 with a degree in Business Marketing. During his undergraduate studies, he was involved with multiple volunteer organizations, such as Camp Kemo a summer camp for children with cancer and Palmetto Richland Children’s Hospital. Currently, he mentors at-risk high-school students and tutors students for Step 1/COMLEX 1. In his spare time he enjoys, golfing, backpacking, cooking, and spending time with family.

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Kevin M. Rice, MD is the president of Global Radiology CME

Dr. Rice is a radiologist with Renaissance Imaging Medical Associates and is currently the Vice Chief of Staff at Valley Presbyterian Hospital in Los Angeles, California. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator.

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