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The first 25 slides, exactly as they appear. The full deck has 72 content slides.
Radiology
Renal Pelvis Dilatation
Built from Obstetric Imaging

What’s inside
7 sections · 72 slides
Overview
- What this deck covers
The finding and what it means
A common, mostly harmless observation that occasionally flags real kidney disease
- Start with the plumbing
- What the scan actually shows
- Naming the finding
- Why the loose terms cause trouble
- “
- 1%-2%
- Most of it comes to nothing
- 12%
- Reading those risk numbers
Measuring the renal pelvis
One plane, one axis, two calipers -- and the thresholds that follow from them
- Where to put the calipers
- The measuring sequence
- Both kidneys measured in cross-section
- Long-axis view of the kidney
- Why the long-axis view earns its place
- Low-risk dilatation in the third trimester
- The two numbers to remember
- The older three-band scheme
- The newer two-band scheme
- Sorting a second-trimester pelvis
- Prenatal and Postnatal Urinary Tract Dilatation (UTD) Risk Categories
- How to read that grid
- Risk categories as printed in the source
Looking beyond the millimetres
Calyces, kidney tissue, ureters, bladder and amniotic fluid all shift the risk
- What every report should state
- Central versus peripheral calyces
- Increased-risk dilatation with peripheral calyces
- Calyceal dilatation getting progressively worse
- Early calyceal dilatation, labelled
- Rounded calyces with cortical compression
- Why rounded calyces matter
- Kidney tissue: thickness and texture
- Severe one-sided dilatation at 18 weeks
- Both kidneys severely dilated at 26 weeks
- Follow the tract downwards: the ureters
- The bladder and the outlet
- Amniotic fluid is usually normal
- The odd exception: too much fluid
- Prove the spaces connect
- When serial scans are worth it
Why the pelvis dilates
Three common answers, and the anatomy behind each
- Three answers cover most cases
- Transient dilatation: the common, benign one
- The link with trisomy 21
- Ureteropelvic junction obstruction: how common
- What is actually wrong at the junction
- How the junction fails
- Vesicoureteral reflux: how common
- The same condition, two very different stories
- How reflux comes about
- From misplaced bud to reflux
- Reflux runs in families
- What else could it be
- Working through that list
- “
What happens next
Rescanning in pregnancy, the newborn ultrasound, and the odds of it settling
- Rescanning during the pregnancy
- The path from first scan to newborn check
- Who needs a newborn scan
- Wait 48 hours before the first newborn scan
- A normal first scan is not the end
- Risk bands after birth
- How soon to repeat after birth
- Bladder study and preventive antibiotics
- Surgery is the exception
- 90%
- Where those figures come from
Bringing it together
What to tell the referring clinician, and the points worth memorising
- What the referring clinician needs to know
- Key points, part one
- Key points, part two
- Suggested readings
- References
- References (continued)
- References (continued)
- Obstetric Imaging: Fetal Diagnosis and Care, 2nd Edition