Acute pyelonephritis: comparison of diagnosis with computed tomography and contrast‐enhanced ultrasonography

Abstract

OBJECTIVE To assess the value of contrast‐enhanced ultrasonography (US) with the contrast pulse‐sequence (CPS) technique for detecting renal parenchymal changes in acute pyelonephritis (APN), compared with contrast‐enhanced computed tomography (CT) as the reference standard. PATIENTS AND METHODS We examined 100 patients (82 women, 18 men; mean age 30.2 years, range 18–67); children (those aged <18 years) were excluded from the study. All patients had clinical symptoms suggestive of APN. For the US a Sequoia 512 (Acuson, Mountain View, CA, USA) unit including CadenceTM CPS technology, with a 6C2 probe, was used. A bolus of a 2.4‐mL US contrast agent SonoVue (Bracco, Milan, Italy) was injected. For CT a multislice 16‐row unit was used (Sensation 16, Siemens, Erlangen, Germany), at a table speed of 2.5 mm/s and a slice thickness of 3 mm; 100 mL of intravenous iodinated contrast agent (flow 3 mL/s) was injected. RESULTS On contrast CT, 84 patients (84%) had renal parenchymal changes suggestive of APN; on contrast US, 82 of the 84 (98%) showed renal parenchymal changes, and APN was correctly diagnosed. Seventy‐six patients (90%) had unilateral and eight (10%) had bilateral APN, and in two (2%) with APN the diagnosis could not be confirmed by US/CPS (false‐negative). No false‐positive findings were detected on US/CPS, which had a sensitivity of 98%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 89%. CONCLUSION CPS/US is accurate for detecting parenchymal changes in APN; it is very sensitive and specific, and allows small renal parenchymal changes to be detected with no radiation exposure.

Contrast enhanced ultrasound of renal masses. A reappraisal of EFSUMB recommendations and possible emerging applications.

“…Mitterberger et al concluded that CEUS allows small renal parenchymal changes in APN to be detected with high specificity (98%), sensitivity (100%) and moreover, without radiation exposure [10]. In several cases (diabetic or immunosuppressed patients) pyelonephritis can be complicated with parenchymal abscess formation.…”

The Clinical Guidelines for Acute Uncomplicated Cystitis and Acute Uncomplicated Pyelonephritis

“…Recently, it has been reported that computed tomography may be more useful than ultrasonography. Especially, the classification according to the degree of parenchymal invasion of the contrast enhancement computed tomography image is associated with the severity and prognosis of pyelonephritis [30][31][32][33].…”

Significance of echotomography in the diagnostic algorithm for acute pyelonephritis and glomerulonephritis

“…[1,2,3] Kako zbog svoje široke dostupnosti, tako i zbog neškodljivosti i lake izvodljivosti, ultrasonografsko ispitivanje predstavlja prvi korak u dijagnostikovanju akutnog pijelonefritisa. [4,5] Medjutim, u studiji Craig WD i autora [6], ukazano je da upotreba CT-a, sa većom sigurnošću dokazuje akutni pijelonefritis, što smo mi i uzimali kao referentni zlatni standard zajedno sa aspiracioniom biopsijom tankom iglom. [7] Postoje mnogobrojni ehotomografski parametri koji ukazuju na akutni pijelonefritis.…”