Tuesday, April 20, 2010

CT of Acute Pyelonephritis

* Inflammation of the renal parenchyma and renal pelvis due to an infectious source

* Most often secondary to an ascending lower urinary tract infection from gram-negative bacteria
- E. coli
- Klebsiella
- Proteus
- Pseudomonas.

* Exception is S. aureus, which is spread hematogenously

Pathologic Causes:
o Vesicoureteral reflux
o Obstruction in the collecting system usually due to a calculus

Signs and symptoms:
- Fever
- Chills
- Flank pain
- Dysuria
- Increased frequency of urination.
- On exam, costovertebral angle tenderness may be present.

Clinical Findings:

1- CBC
- Elevated white blood cell count.

2- Urinalysis
- Bacteriuria
- Pyuria
- White blood cell casts

3- Acute pyelonephritis is clinical diagnosis,
- Radiographic imaging is used to evaluate underlying pathology
- Rule out any complications as:
-Emphysematous pyelonephritis.....Most often occurs in diabetics Can produce gas in the collecting system and renal parenchyma.

Right kidney is markedly enlarged and has a wedge-shaped area of low attenuation

Radiographic Imaging Findings:
$ Enlarged kidneys (U/S and CT)
$ Hydronephrosis (U/S and CT)
$ Wedge shaped areas of low attenuation secondary to decreased perfusion (CT)
$ Loss of the ability to distinguish the corticomedullary border (CT)
$ Perinephric stranding (CT)


o Antibiotics for non-complicated pyelonephritis.
o Radical nephrectomy for emphysematous pyelonephritis.
o Percutaneous drainage of abscesses

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Answer this case

Look at the following case. Why is this an emergency? The patient has:

a. A tension pneumothorax.
b. An acute pneumonia of the right lung.
c. Had a pulmonary embolism.
d. A simple pneumothorax.
e. Been shot.


There is a large, right-sided, tension pneumothorax that is displacing the heart and mediastinal structures to the left. Tension pneumothoraces can result from penetrating injuries or can arise spontaneously. They are serious because air exchange is compromised in both the lung with the pneumothorax and the opposite lung which is being compressed. They are treated by decompressing the tension and re-expanding the lung.

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Topic is Hyperthyroidism and all the different types and how to distinguish between them:
Topics Include:
-Grave's Disease
-Silent Thyroiditis
-Subacute Thyroiditis
-Euthyroid Sick Syndrome
-Pituitary Adenoma
-Exogenous Administration

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