eGFR before contrast

CKD-EPI 2021 (race-free).

Age (years) Serum creatinine (mg/dL) Sex at birth MaleFemale Calculate eGFR

Ellipsoid volume and PSA density

Length × width × height × π/6. PSA is optional.

Length (cm) Width (cm) Height (cm) PSA (ng/mL, optional) Calculate volume

Adrenal washout

Attenuation in Hounsfield units (HU).

Unenhanced (HU) Portal venous (HU) Delayed, 15 min (HU) Calculate washout

Nodule volume doubling time

Assumes a spherical nodule.

Prior diameter (mm) Current diameter (mm) Days between scans Calculate VDT

CT effective dose

DLP × region-specific conversion factor.

DLP (mGy·cm) Body region Head Neck Chest Abdomen Pelvis Abdomen and pelvis Estimate dose

BMI and body surface area

Useful for dosing and cardiac indexing.

Weight (kg) Height (cm) Calculate BMI and BSA

Weight-based contrast dose

Volume = weight × iodine dose ÷ concentration.

Weight (kg) Iodine dose (mgI/kg) Agent concentration (mgI/mL) Injection duration (s, optional) Calculate volume

ACR TI-RADS

Thyroid nodule ultrasound score (2017).

Composition Cystic or spongiform (0) Mixed cystic and solid (1) Solid (2) Echogenicity Anechoic (0) Hyper- or isoechoic (1) Hypoechoic (2) Very hypoechoic (3) Shape Wider than tall (0) Taller than wide (3) Margin Smooth or ill-defined (0) Lobulated or irregular (2) Extra-thyroidal extension (3) Echogenic foci (select all that apply) Large comet-tail artifacts (0) Macrocalcifications (1) Peripheral or rim calcifications (2) Punctate echogenic foci (3) Largest dimension (cm, optional) Score nodule

Carotid stenosis (NASCET)

Percent narrowing versus the distal internal carotid.

Narrowest lumen (mm) Distal normal lumen (mm) Calculate stenosis

Ejection fraction

From cardiac MRI or CT volumes.

End-diastolic volume (mL) End-systolic volume (mL) Heart rate (bpm, optional) Calculate EF