Non-visualized kidney

1. Renal agenesis
2. Renal ectopia
3. Nonfunctioning kidney BACK to TOP 

Displaced kidney

1. Horseshoe kidney/pelvic kidney
2. Hepatomegaly/splenomegaly
3. Adrenal mass-downward
4. Bochdalek hernia-upward BACK to TOP

Unilateral small kidney

1. Renal Ischemia/Renal Artery Stenosis/ Fibromuscular hyperplasia
2. Renal Infarction-Usually due to embolism
3. Postinflammatory/Post-obstructive atrophy
4. Radiation
5. Reflux atrophy BACK to TOP 

Bilateral small smooth kidneys

1. Bilateral atherosclerosis/embolism
2. Chronic Medical Renal Disease
   • Chronic glomerulonephritis
   • Hypertension
   • Analgesic nephropathy BACK to TOP

Unilateral large, smooth kidney

1. Ureteral obstruction
2. Renal duplication
3. Pyelonephritis
4. Acute Renal Vein Thrombosis
5. Acute Arterial Occlusion BACK to TOP 

Bilateral large smooth kidneys

1. Diabetes
2. Acute Glomerulonephritis
3. Collagen vascular diseases-SLE, Goodpasture’s, Wegener’s
4. Vasculitis-Polyarteritis nodosa
5. Malignancy-Lymphoma/Leukemia
6. Duplicated collecting systems BACK to TOP 

Bilateral Renal Enlargement with masses

1. PCKD
2. Lymphoma
3. Von Hippel-Lindau disease
4. Tuberous Sclerosis BACK to TOP 

Increasingly dense unilateral nephrogram

1. Obstruction
2. Renal vein thrombosis
3. Renal artery stenosis BACK to TOP 

Persistent bilateral nephrogram

1. Hypotension/shock
2. ATN
3. Acute glomerulonephritis BACK to TOP 

Medullary Nephrocalcinosis

1. Renal tubular acidosis
2. Medullary sponge kidney
3. Hypercalcemia

• Sarcoidosis
• Milk-alkali syndrome
• Hyperparathyroidism
• Vitamin D intoxication BACK to TOP

Pelvocalyceal Differential Diagnoses 

Papillary Necrosis

1. NSAIDS
2. Sickle Cell Disease
3. Analgesic nephropathy
4. Infection (Tb)
5. Diabetes BACK to TOP

Renal sinus mass effect

1. Parapelvic cyst
2. Renal sinus lipomatosis
3. Vascular abnormalities
4. Solid tumors of renal sinus BACK to TOP

Clubbing or destruction of renal calyces

1. Papillary necrosis
2. TB
3. Chronic pyelonephritis
4. Hydronephrosis
5. Congenital megacalyces BACK to TOP 

Extra-calyceal contrast

1. TB
2. Papillary necrosis
3. Calyceal Diverticulum
4. Medullary Sponge Kidney
5. Post-obstructive BACK to TOP 

Lateral proximal ureteral deviation

1. Lymphadenopathy
2. Psoas hypertrophy
3. Aortic aneurysm
4. Retroperitoneal mass BACK to TOP 

Medial deviation of proximal or mid ureter

1. Renal or Retroperitoneal mass
2. Retrocaval ureter
3. Retroperitoneal Fibrosis BACK to TOP

Medial displacement distal ureters

1. Pelvic lymphadenopathy
2. Pelvic lipomatosis
3. Iliopsoas muscle hypertrophy
4. Bilateral iliac artery aneurysm
5. S/P AP resection BACK to TOP 

Intraluminal filling defects renal pelvis/calyces/ureters

1. Calculus
2. Blood clot
3. TCC
4. Sloughed Papilla
5. Fungus ball
6. Air bubble (if post-instrumentation) BACK to TOP 

Ureteral filling defects

1. Tumor-TCC
2. Infection-TB, Schistosomiasis
3. Response to infection-Ureteritis cystica
4. Leukoplakia
5. Malacoplakia BACK to TOP 

Obstruction of the ureter

1. Calculus
2. Adjacent inflammatory disease
3. Malignancy
4. Ureterocele
5. Retroperitoneal fibrosis
6. Stricture
   • Congenital
   • Acquired (Instrumentation)
   • Infection (TB, Schisto)
   • Radiation BACK to TOP 

Ureteral Calcification

1. TB
2. Schistosomiasis
3. Calculi (Steinstrasse) BACK to TOP 

Small urinary bladder

1. Transitional cell CA
2. Cystitis
3. Pelvic hematoma
4. Pelvic lipomatosis
5. TB/schistosomiasis BACK to TOP 

Enlarged urinary bladder

1. Bladder outlet obstruction
2. Neurogenic bladder
3. Diabetes
4. Absent abdominal wall musculature BACK to TOP 

Urinary bladder filling defect

1. Calculus
2. Blood clot
3. Neoplasm
4. Prostatic enlargement
5. Ureterocele BACK to TOP 

Air in urinary bladder

1. Emphysematous cystitis
2. Iatrogenic
3. Bladder fistula from diverticulitis, Crohn’s BACK to TOP 

Bladder Calcification

1. Schistosomiasis
2. TB
3. Cystitis
4. Bladder Calculus
5. Bladder neoplasm BACK to TOP

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