The For Kidneys Sake podcast series is brought to you by Imperial College Healthcare NHS Trust and North West London Integrated Care Board (NWL NHS)

An ultrasound report lands in your inbox. It mentions a cyst. Or a bright kidney. Or “thin cortex.” Or asymmetry. And suddenly, what was meant to reassure becomes a source of anxiety. In this highly practical episode, Prof Jeremy Levy and Dr Andrew Frankle tackle the six most common renal ultrasound findings that trigger GP referrals and explain what actually matters (and what really doesn’t).

From simple cysts and Bosniak classifications to angiomyolipomas, echogenic kidneys, cortical thinning, scars, and asymmetric kidneys, this episode cuts through the noise. The golden rule? Context is everything. Kidney health checks, eGFR, urine ACR, blood pressure, trump scan wording almost every time. Clear, calm, and clinically grounded, this is 15 minutes that could save you hours of unnecessary worry and referrals. Listen in and interpret with confidence.

Top 5 Takeaways

1. Simple cysts are simple - Bosniak 1 or 2 cysts need no follow-up. Reassure and move on. Complex cysts, however, go to urology — not nephrology.

2. Angiomyolipomas rarely matter - If under 40mm, they’re almost always benign and only need one follow-up scan at 12 months. Refer only if >40mm or in women of childbearing age.

3. “Bright kidneys” mean nothing without context - Check eGFR, urine ACR, and blood pressure. If all normal, ignore the scan comment.

4. Thin cortex or scarring is usually congenital - In patients with normal kidney health checks, these findings are benign variants. In younger patients with suboptimal GFR, code as G2 and monitor annually.

5. Asymmetry is common - A 1cm size difference is often physiological. Only worry if there’s uncontrolled hypertension, rapid GFR decline, pulmonary oedema, or significant size discrepancy.

Resource Links:
NICE GUIDELINES [NG203] chronic kidney disease: assessment and management Overview | Chronic kidney disease: assessment and management | Guidance | NICE

Northwest London CKD guidelines for primary care Chronic kidney disease (nwlondonicb.nhs.uk)

The purpose of this podcast is to inform and educate health care professionals working in the primary care and community setting. The content is evidence based and consistent with NICE guidelines and North West Guidelines available at the time of publication.

The content of this podcast does not constitute medical advice and it is not intended to function as a substitute for a healthcare practitioner’s judgement.

You can also join the community by signing up to our newsletter here

Produced by award-winning media and marketing specialist Heather Pownall of Heather's Media Hub

From Cysts to Cortex: Interpreting Kidney Ultrasounds