Learning objectives
- To explain the role of radiologists and indications of imaging techniques in acute pyelonephritis and its complications
- To review the different pathologies that may derive or are associated with pyelonephritis.
- To understand the importance of radiologic findings in the assessment for course of treatment.
Background
Pyelonephritis is a severe urinary tract infection that affects both the parenchyma and the collecting system.
The annual incidence is estimated in around 10.5 million to 25.9 million people in the world [1],
with more prevalence amongst women.
The most frequent bacteria responsible is Escherichia Coli.
Renal affection may arise from haematogenous spread or more commonly from the urinary tract [2],
where bacteria colonise the urine in the bladder and are able to migrate upwards to the collecting system and parenchyma.
Diagnosis is clinical and...
Findings and procedure details
Imaging modalities of choice in an acute setting are ultrasonography (US) and Computed Tomography (CT)[3].
Magnetic Resonance Imaging (MRI) is an option for pregnant patients or patients with severe kidney failure where iodine contrast is restricted.
Imaging should be performed if[4]:
Persistent fever after 72 hours of antibiotic treatment.
Decreased renal function.
Risk factors such as badly controlled diabetes,
immunodeficiency and renal transplant.
Suspected structural or functional abnormalities.
Severe symptoms and life-threatening situations (sepsis).
Fig. 1
No follow-up image should be done unless new clinical...
Conclusion
Kidney infection is one of the most frequent infections in the world.
While a non-complicated infection can be managed without the necessity of imaging techniques,
radiologists play a pivotal role in diagnosing complications of renal infection and can guide into the necessity of surgical treatment.
Radiologists should be able to recognize the different complications and findings in order to perform an accurate diagnosis.
References
[1]-Czaja CA,
Scholes D,
Hooton TM,
Stamm WE.
Population-based epidemiologic analysis of acute pyelonephritis.
Clin Infect Dis 2007;45:273-80
[2]-Choong FX,
Antypas H,
Richter-Dahlfors A.
Integrated Pathophysiology of Pyelonephritis.
Microbiol Spectr.
2015 Oct.
3 (5)
[3]-William D.
Craig,
Brent J.
Wagner,
Mark D.
Travis.
Pyelonephritis: Radiologic-Pathologic Review RadioGraphics 2008; 28:255–276.
[4]-[Guideline] Expert Panel on Urologic Imaging: Nikolaidis P,
Dogra VS,
Goldfarb S,
Gore JL,
Harvin HJ,
et al.
ACR Appropriateness Criteria® Acute Pyelonephritis.
J Am Coll Radiol.
2018 Nov.
15 (11S):S232-S239.
[5]-Vourganti S,
Agarwal PK,
Bodner...