EM Vivas · Imaging choice and radiation risk
Dose catalog and pregnancy imaging viva
Data viva on ALARA, mSv numbers, contrast caveats and pregnancy imaging principles.
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ACEMFRCEMABEM
Prompt
Quote effective doses for CXR, CT head, CTPA, CTAP. Counsel a pregnant patient needing PE workup.
Interpretation
Reveal interpretationShowHide
ALARA. Justify the study, optimise protocol, limit dose/repeats.[1]
Order-of-magnitude doses. CXR ~0.02 mSv; CT head ~2 mSv; CTPA ~5–8 mSv; CT abdomen/pelvis ~10 mSv; natural background ~3 mSv/year.[1]
Pregnancy. Confirm pregnancy status; prefer US/MRI when they answer the question; perform CT if maternal benefit requires it; counsel absolute fetal risk usually low versus untreated PE.[3]
Contrast. Iodinated: allergy/AKI context; gadolinium: avoid in severe renal failure (NSF risk), prefer group II agents when MRI essential.[2]
References3ShowHide
- [1]Mettler FA Jr, Huda W, Yoshizumi TT, et al. Effective doses in radiology and diagnostic nuclear medicine: a catalog. Radiology, 2008.PMID 18566177
- [2]Weinreb JC, Rodby RA, Yee J, et al. Use of Intravenous Gadolinium-based Contrast Media in Patients with Kidney Disease: Consensus Statements from the American College of Radiology and the National Kidney Foundation. Radiology, 2021.PMID 33170103
- [3]American College of Obstetricians and Gynecologists Committee Opinion No. 723: Guidelines for Diagnostic Imaging During Pregnancy and Lactation. Obstet Gynecol, 2017.PMID 28937575