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Paediatric nuclear medicine
In children the goal is a diagnostic image at the lowest activity: weight-based activity from the harmonised EANM and SNMMI tables, preparation that reduces motion and allows voiding, and choosing a study that answers a question radiation-free imaging did not answer.
Why it matters in the exam
The exam asks about studies specific to children. Urinary tract: DMSA for scars after pyelonephritis (at least 6 months after the infection); MAG3 with a diuretic for renal pelvic dilation — not in the first weeks of life, because the kidney is still immature (usually from about 4–6 weeks of age); radionuclide cystography to follow reflux. GI tract: Meckel scan for a child with painless rectal bleeding; HIDA with phenobarbital for a newborn with conjugated jaundice; a "milk scan" for an infant with recurrent vomiting — it shows gastro-oesophageal reflux and aspiration into the lungs.
Neuroblastoma: I-123 MIBG is taken up by most tumours and is used for staging and follow-up, with a semi-quantitative score (Curie or SIOPEN); when the tumour does not take up MIBG, FDG is used. Congenital hypothyroidism: pertechnetate or I-123 imaging separates absent gland, ectopic gland (usually lingual) and a synthesis defect; the study is done in the first days, and levothyroxine treatment must not be delayed for it. Bone scintigraphy in children: osteomyelitis, osteoid osteoma and occult fractures; in suspected abuse an X-ray skeletal survey is the basis, and the scan complements it, for example for rib fractures.
Preparation: explanation to the child and parents, a parent present, anaesthetic cream, gentle immobilisation, and sometimes anaesthesia; drinking and bladder emptying reduce radiation to the bladder and pelvis. Growth plates take up intensely on bone scans and are not lesions. Breastfeeding after a study in the mother: after FDG there is no need to stop, and after Tc-99m agents most require no interruption or only a short one; after I-131 breastfeeding must stop completely. The radiation to the child is much lower when activity is adjusted, and a justified study should not be withheld for fear of radiation.
Key points
- Weight-based activity per the EANM and SNMMI tables.
- DMSA for scars; MAG3 for obstruction from about 4–6 weeks.
- Meckel, HIDA and the milk scan are key paediatric studies.
- Neuroblastoma — MIBG.
- Congenital hypothyroidism — do not delay treatment.
Summary table
| Problem | Study | Key point |
|---|---|---|
| Scar after pyelonephritis | DMSA | At least 6 months after the infection |
| Renal pelvic dilation | MAG3 with diuretic | Not in the first weeks of life |
| Painless rectal bleeding | Pertechnetate for Meckel | H2 blocker beforehand |
| Conjugated jaundice in a newborn | HIDA with phenobarbital | Bowel activity excludes atresia |
| Neuroblastoma | I-123 MIBG | Curie or SIOPEN score |
| Congenital hypothyroidism | Pertechnetate or I-123 | Do not delay levothyroxine |
In the full version for subscribers
- A simple algorithm
- Memory aid
- Exam traps
- 5 review cards
- Enough for IMLE
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Sources
- EANM Paediatric Dosage Card and North American Consensus Guidelines for Paediatric Administered Activity (harmonised), 2016 — Weight-based activities
- EANM Guidelines on Renal Cortical Scintigraphy and Diuretic Renography in Children, 2017 — Timing, hydration and interpretation
- EANM Procedure Guideline for I-123 MIBG Scintigraphy in Neuroblastoma, 2018 — Indications and semi-quantitative scoring
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.