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Radiology
Unilateral Renal Agenesis
Built from Obstetric Imaging
What’s inside
6 sections · 57 slides
Overview
- What this topic covers
One kidney, from the start
Definition, how common it is, and why it is not a harmless finding
- What the words mean
- Two different ways to end up with one working kidney
- Absent kidney or useless kidney?
- Why this is not a harmless finding
- Born with one kidney is not the same as losing one
- 1:2000
- Who it happens to
- Scans are catching it far more often
Why a kidney fails to form
Embryology, family clustering, genes, and the slow damage to the kidney that remains
- How a kidney gets built
- Stages of kidney development in the embryo
- Two ways the build can fail
- It runs in families
- The genes behind it
- Why one kidney can wear out over decades
- The kidney that is there often grows bigger
What travels with it
The remaining kidney, other organs, uterine anomalies and named syndromes
- A missing kidney rarely travels alone
- Problems in the kidney that is left
- What shows up after birth
- What vesicoureteral reflux means
- Contrast flowing backwards from bladder to kidneys
- Anomalies outside the urinary tract
- Uterine anomalies in girls
- When a blocked vagina joins the picture
- Doubled uterus with a blocked vaginal half
- Named syndromes that include a missing kidney
- What to offer the parents
Finding it on the scan
Empty renal fossa, the lying-down adrenal sign, and one renal artery on colour Doppler
- The first clue is an empty space
- Only the adrenal gland in one renal fossa
- Telling the adrenal gland from a kidney
- The lying-down adrenal sign
- Reading the lying-down adrenal
- Flattened adrenal filling the renal fossa
- Counting the renal arteries
- A single renal artery leaving the aorta
- Measuring the kidney that is there
- Enlarged solitary kidney near term
- A search order when a kidney is missing
- The three classic signs
- What else can look like this
- The pitfall worth repeating
- When one missing kidney becomes lethal
- Fetal therapy - still experimental
After birth and for life
Confirming the diagnosis, testing for reflux, and lifelong surveillance
- The newborn
- Testing for reflux
- A single kidney on cross-sectional imaging
- The three long-term risks
- What pushes the risk up or down
- What follow-up looks like
- Two extra steps that are easy to forget
- How it turns up when the scan missed it
- What the referring clinician needs to know
- Key points
- References
- References (continued)
- References (continued)
- Obstetric Imaging: Fetal Diagnosis and Care, 2nd Edition