Diagnostic Ultrasound - Abdomen and Pelvis

Column of Bertin, Kidney
TERMINOLOGY
Synonyms
• Hypertrophic or enlarged column of Bertin, junctional
parenchyma, lobar dysmorphism, renal pseudotumor, renal
septum, septal cortex, focal cortical hyperplasia, benign
cortical rest
Definitions
• Hypertrophic band of normal cortical tissue that separates
pyramids of renal medulla
IMAGING
General Features
• Best diagnostic clue
○ Isoechoic and continuous with renal cortex, indenting
renal sinus laterally
○ No abnormal vascularity
• Location
○ At junction of upper and middle 1/3 of kidney
○ Left side > right side
○ Unilateral > bilateral (18% of cases)
• Size
○ Less than 3 cm
Ultrasonographic Findings
• Grayscale ultrasound
○ Homogenous round lesion isoechoic to renal cortex
○ Extends between renal pyramids
○ Normal renal contour
○ Bordered by echogenic junctional parenchymal line and
echogenic triangular junctional parenchymal defect
○ Indentation of renal sinus laterally
○ Echogenicity may be increased because of anisotropy
• Color Doppler
○ Normal perfusion indicating normal renal tissue
○ No vascular distortion with preserved arcuate arteries
surrounding pyramids
○ No abnormal vessels
• Contrast-enhanced ultrasound
○ Enhancement of column of Bertin is identical to normal
renal cortex on all phases
CT Findings
• CECT
○ Similar enhancement as normal renal cortex on
corticomedullary and excretory phases
MR Findings
• Similar signal intensity to renal cortex on T1WI, T2WI, and
contrast-enhanced sequences
DIFFERENTIAL DIAGNOSIS
Renal Tumor
• Renal cell carcinoma
• Lymphoma
• Angiomyolipoma
• Metastases
○ Masses usually differ in echogenicity from renal cortex
and may be heterogeneous
○ Doppler: Masses may be hypervascular or displace
arcuate arteries
Renal Scarring
• Cortical loss at site of scarring
• Adjacent compensatory hypertrophy of unaffected tissue
Renal Duplication
• 2 central echogenic renal sinuses separated by intervening
bridging renal parenchyma
Dromedary Hump
• Hypoechoic pseudotumor composed of normal renal tissue
• External bulge on renal contour
• Left sided
• Secondary to moulding of kidney by spleen
PATHOLOGY
General Features
• Embryology: Incomplete resorption of polar parenchyma of
subkidneys that fuse to form normal kidney
○ Normal renal development: Superior and inferior
subkidneys corresponding to upper and lower calyces
fuse, with upper pole of inferior subkidney overlapping
lower pole of superior subkidney
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Asymptomatic, normal variant
• Diagnosis
○ Usually found incidentally on imaging
○ Most likely to simulate mass on sonography
○ Optimize ultrasound by focusing on lesion and placing it
in center of FOV
DIAGNOSTIC CHECKLIST
Consider
• Normal variant, but can mimic solid tumor
Image Interpretation Pearls
• Isoechoic to, and continuous with, renal cortex
• Normal perfusion, no vascular distortion
• No mass on CECT or T1WI C+
• In duplication, bridging parenchyma separates collecting
systems; in column of Bertin, there is no bridging
SELECTED REFERENCES
1. McArthur C et al: Current and potential renal applications of contrastenhanced
ultrasound. Clin Radiol. 67(9):909-22, 2012
2. Fretzayas A et al: Differential diagnosis of renal mass. Columns of Bertin.
Pediatr Nephrol. 25(3):441-4, 2010
3. Yeh HC: Some misconceptions and pitfalls in ultrasonography. Ultrasound Q.
17(3):129-55, 2001
4. Yeh HC et al: Junctional parenchyma: revised definition of hypertrophic
column of Bertin. Radiology. 185(3):725-32, 1992
5. Lafortune M et al: Sonography of the hypertrophied column of Bertin. AJR
Am J Roentgenol. 146(1):53-6, 1986
Diagnoses: Urinary Tract
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