Glomerulonephritis through the lens of ultrasound and radiology

Table 4 Clinician-oriented overview linking common clinical questions in glomerulonephritis to imaging modalities and clinical setting¹

Clinical question	Main clinical aim	Most appropriate imaging modality	Primary clinical endpoint	Clinical setting	Rationale
Acute vs chronic disease?	Disease staging	B-mode ultrasound	Chronicity	Standard of care	First-line tool to assess kidney size, cortical thickness, and corticomedullary differentiation
Renal perfusion impairment?	Functional assessment	Doppler ultrasound; CEUS	Perfusion	Standard of care/adjunct	Evaluation of renal blood flow and microvascular perfusion
Active inflammation vs fibrosis?	Activity vs chronic damage	CEUS; elastography	Activity/fibrosis	Adjunct/emerging	CEUS reflects inflammatory hyperemia; elastography estimates tissue stiffness
Extent of interstitial fibrosis?	Prognostic stratification	Elastography; MRI	Fibrosis	Adjunct	Non-invasive estimation of tissue stiffness and parenchymal remodeling
Tubulointerstitial involvement?	Tissue characterization	Multiparametric MRI	Tissue characterization	Adjunct	Provides complementary functional and structural information
Metabolic or inflammatory activity?	Molecular assessment	PET imaging	Activity	Emerging/research	Detects metabolically active inflammatory tissue
Risk stratification and outcome prediction?	Prognosis	Emerging imaging tools (Radiomics; AI)	Monitoring/prognosis	Research	Quantitative analysis of imaging features for predictive modeling

¹Imaging techniques provide complementary non-invasive information on renal morphology and function but cannot replace histopathological evaluation. Renal biopsy remains the reference standard for definitive diagnosis and should be performed whenever clinically indicated.

AI: Artificial intelligence; CEUS: Contrast-enhanced ultrasound; MRI: Magnetic resonance imaging; PET: Positron emission tomography.