Diagnostic Ultrasound - Abdomen and Pelvis

Hyperechoic Kidney
○ Echogenic cortex, dilated calyces with overlying cortical
scarring
Helpful Clues for Less Common Diagnoses
• Vasculitis
○ Polyarteritis nodosa, Wegener granulomatosis
○ Small kidneys with ↑ cortical echogenicity
○ May have focal scarring and fibrosis
• Ischemia
○ Renal artery stenosis or fibromuscular dysplasia
– Low intrarenal RI, tardus parvus waveform
○ Renal vein thrombosis
– Absent venous flow, reversal of arterial diastolic flow
○ Renal artery thrombosis
– Global or segmental loss of arterial flow
○ Asymmetrical, initially enlarged and hypoechoic
○ Later, small and hyperechoic with global decreased
perfusion
○ May have segmental wedge-shaped areas of scarring
and decreased perfusion
• Lupus Nephritis
○ Acute: Renal echogenicity and size are nonspecific
○ Chronic: Small and echogenic kidney
• Chronic Renal Transplant Rejection/Chronic Allograft
Nephropathy
○ End result of rejection and other insults
○ Occurs months to years after transplantation
○ Results in interstitial fibrosis
○ Echogenic kidney with decrease in size and perfusion ±
calcifications
• Multicystic Dysplastic Kidney
○ Initially unilateral multicystic lesion with hyperechoic
dysplastic renal parenchyma
○ Later cysts shrink and parenchyma remains echogenic
• HIV Nephropathy
○ Occurs almost exclusively in African American descent
○ Present with nephrotic syndrome and may progress
rapidly to end-stage renal disease
○ Typically large echogenic kidneys with preserved CMD
○ Later sinus blends with cortex and kidneys become small
• Acute Cortical Necrosis
○ Subcapsular area spared, hypoechoic rim initially
○ Rapid cortical calcification may ensue:
Curvilinear/shadowing
○ Diffuse ↑ parenchymal echogenicity
Helpful Clues for Rare Diagnoses
• Emphysematous Pyelonephritis
○ Diabetes, immunocompromise, clinical picture of sepsis
○ Gas-forming necrotizing renal infection
○ Diffuse or segmental
○ Bright echoes with posterior dirty shadowing
• Autosomal Recessive Polycystic Kidney Disease
○ Detected prenatally by ultrasound
○ Symmetrically enlarged echogenic kidneys
○ Innumerable small cysts
○ Echogenicity increased due to multiple reflections from
small cyst walls
• Oxalosis
○ Characterized by combined cortical and medullary
nephrocalcinosis
○ Hyperechoic kidneys; absent CMD
• Alport Syndrome
○ Inherited disease with hematuria, proteinuria,
hypertension, and deafness
○ Initially normal kidneys, later small and echogenic
• Renal Amyloidosis
○ Enlarged kidneys in acute phase, ↓ cortical echogenicity
○ Chronic: ↓ renal size & ↑ echogenicity
• Renal Tuberculosis
○ Chronic parenchymal atrophy, hydronephrosis,
calcifications
○ Calcified small kidney "autonephrectomy"
• Lithium Nephropathy
○ Innumerable tiny cysts in cortex and medulla of normalsized
kidneys
○ Cysts produce bright punctate echoes
Differential Diagnoses: Kidney
Diabetic Nephropathy
Chronic Glomerular Diseases
(Left) Longitudinal ultrasound
of a normal-sized right kidney
in early chronic kidney disease
is shown. The renal cortex ſt
is isoechoic to slightly
hyperechoic to the liver .
Pyramids st are prominent.
These findings are common in
medical renal disease and not
specific as to cause. (Right)
Longitudinal ultrasound of a
normal-sized right kidney with
diffuse increase in cortical
echogenicity ſt is shown.
Pyramids are not conspicuous.
The renal sinus st is barely
seen.
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