Urinary tract infections

Extrapulmonary

tuberculosıs: an old but resurgent problem. Axial (a) and coronal (b) non-contrast CT scan of a 74-year-old male with urinary tuberculous reveal debris collection within the dilated right renal pelvis and dilated right ureter with diffuse wall thickening. 3D MIP Coronal T2-weighted MR urogram shows strictures (arrows) of the right ureter

insightsimaging.springeropen.com • CC-by-4.0

Extrapulmonary

tuberculosıs: an old but resurgent problem. A 47-year-old male. Coronal post-contrast CT scan shows diffuse thickening of the bladder wall (arrow) and dilated left proximal ureter (arrowheads). Urinary TB

insightsimaging.springeropen.com • CC-by-4.0

Urinary tract

infection • Severe urinary tract infection with complicating prostatic abscess - Ganzer Fall bei Radiopaedia

Alabd M, Severe urinary tract infection with complicating prostatic abscess. Case study, Radiopaedia.org (Accessed on 11 Aug 2023) https://doi.org/10.53347/rID-41479 • CC by-nc-sa 3.0 (modified)

Radiopaedia • CC-by-nc-sa 3.0 • de

Urinary tract infection (UTI) is a common clinical condition involving the bladder (cystitis) and kidneys (pyelonephritis). It is commonly divided into 'uncomplicated' and 'complicated' infections.

Clinical presentation

painful urination
strangury
bloody, dark, cloudy urine
urinary frequency
urinary incontinence
urinary urgency
systemic symptoms: fevers, chills, rigors, tiredness, confusion

Pathology

UTIs occur when there is bacterial colonization of the uroepithelium and a subsequent inflammatory response. Classically, the urine and urinary collecting system were considered sterile, however, there is some debate on whether a small amount of bacterial colonization is normal . Given this, and that voiding urinary samples may be contaminated by skin or rectal reservoir flora, bacteriuria is suggestive of a UTI, but bacteriuria and pyuria (white blood cells in the urine) is much more specific for infection.

Uncomplicated vs complicated UTI

uncomplicated: an otherwise healthy patient with a structurally and functionally normal urinary tract
complicated: factors are present that decrease the likelihood of therapy being effective
- urinary tract is structurally or functionally abnormal
- immunocompromised status
- especially virulent pathogen
- factors that may make a patient complicated
  - male
  - childhood UTIs
  - immunocompromised
  - pregnancy
  - elderly
  - diabetes mellitus
  - failed antibiotic course
  - extended symptoms before presentation

Treatment and prognosis

Uncomplicated

These patients are usually well managed with a course of oral antibiotics.

Many imaging algorithms suggest that imaging for uncomplicated cystitis or pyelonephritis is unnecessary.

Complicated

These patients have often failed a course of antibiotics and may benefit from imaging:

lower urinary tract
- CT urography: for evaluation of structural abnormalities and possible abscess formation; MRI could be considered if the patient has an allergy to contrast
- ultrasound has a secondary role
upper urinary tract
- CT abdomen with contrast (or without and with contrast)
- MRI abdomen: for patients with contrast allergies and pregnant patients
- renal and bladder ultrasound: second line, relative to CT it is not as good at detecting renal parenchymal changes and/or characterizing perinephric extension of infection