Role of diffusion-weighted MRI in acute pyelonephritis: a prospective study

Abstract

ADC values derived from the diffusion sequence have significantly lower values in renal abscesses than in areas of nephritis.

Acute pyelonephritis in transplanted kidneys: can diffusion-weighted magnetic resonance imaging be useful for diagnosis and follow-up?

“…Our results showed that the 46 inflammatory foci had statistically lower ADC values (1.43 ± 0.32 9 10 -3 mm 2 /s) than healthy parenchyma, as measured in the 22 patients with suspected APN (2.06 ± 0.16 9 10 -3 mm 2 /s) and in the 26 patients without suspected APN (1.99 ± 0.14 9 10 -3 mm 2 /s). The ADC ability to identify APN foci in transplanted kidneys, as estimated by the ROC curve, was excellent (95% CI for AUC 0.995-1), determining ADC < 1.9 9 10 -3 mm 2 /s as the region typical of APN foci (PPV = 94% and NPV = 100%) The role of diagnostic imaging in confirming a clinical suspicion of APN and its impact on treatment decisions has been reported by several studies [14][15][16][17][18][19]. In particular it was also emphasized that imaging is indispensable for confirming treatment effectiveness during follow-up [20].…”

“…In particular it was also emphasized that imaging is indispensable for confirming treatment effectiveness during follow-up [20]. DW-MRI with ADC allows functional evaluation of renal lesions and was proved to be reliable for diagnosing APN in native kidneys by several authors [14][15][16][17]. On the contrary, there are still relatively few studies in the literature on the use of DWI in transplanted kidneys, even if the initial results on its use for the assessment of early graft deterioration encountered in nearly 30% of renal allografts seem encouraging [21][22][23][24].…”

“…MR without contrast media, particularly Diffusionweighted magnetic resonance imaging (DW-MRI) and the apparent diffusion coefficient (ADC) value have already been shown capable to distinguish healthy kidney functions from pathologic ones in native kidneys [14][15][16][17]. In particular one study on the diffusion and microcirculation properties of tissues in native kidneys identified three ADC value brackets corresponding, respectively, to healthy parenchyma, acute pyelonephritis (APN) foci, and abscesses, suggesting that ADC maps could be a reasonable alternative to contrast-enhanced MR imaging when contrast media are contraindicated [14].…”

Multimodality Imaging Findings of a Renal Aspergilloma

“…A limitation of diffusion is a common finding for brain abscesses and indicates a high cellular content and hyperviscosity (7). Rathod et al (8) stressed the role of DWI without contrast in the diagnosis of renal abscesses. The differential diagnosis of renal aspergilloma includes primary and secondary renal malignancies (particularly RCC), lymphoma, bacterial pyelonephritic abscess, renal tuberculosis, and infarction with central necrosis (6).…”

PieloRM: Una nueva herramienta en el estudio de pielonefritis aguda en pediatría

“…El cintigrama renal DMSA ha sido considerada la técnica de referencia para demostrar pielonefritis aguda (PNA), pero de acuerdo a las guías internacionales actuales no se recomienda su uso rutinario 1,2 . Varios estudios han mostrado la utilidad de la resonancia magnética (RM) en niños con PNA y en los últimos años algunas publicaciones han demostrado que las secuencias de difusión (DWI) son comparables a las secuencias standard contrastadas con gadolinio en la capacidad de identificar compromiso parenquimatoso renal en niños con sospecha de PNA 3,4,5,6 . …”