We read with great interest the article by Caroli et al., in which they meticulously discuss the role of imaging in elucidating both structural and functional aspects of kidney disease. Herein, we would like to briefly comment on evaluation of renal venous congestion in clinical practice.

Renal perfusion, determined by the difference between forward flow/mean arterial pressure and venous resistance/right atrial pressure, is particularly important in management of disorders associated with deranged fluid balance, such as cardiorenal syndrome and hepatocardiorenal syndrome.

However, traditional imaging primarily focuses on the adequacy of forward flow and ignores the deleterious effect of venous congestion on the kidney.

In this context, point-of-care ultrasonography can provide valuable insights into renal hemodynamics by allowing qualitative and semiquantitative assessment of the venous flow pattern.

Intrarenal venous Doppler assesses blood flow in the interlobar veins; in the absence of intra-abdominal hypertension, the flow pattern in these veins reflects changes in right atrial pressure.

The normal waveform is relatively continuous; and as the right atrial pressure increases, it becomes increasingly pulsatile.

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