Bosniac 2019 Renal Cyst Calculator

Renal Mass Protocol CT and <25% enhancing tissue and no macroscopic fat

If No, then_______?

Homogeneous and 21-30 HU
-or-
Homogeneous, low attenuation, too small to characterize

Homogeneous and 270 HU or -9 to 20 HU
-or-
Homogeneous, low attenuation, too small to characterize

Any one of:
Heterogeneous non- enhancing
Hyperattenuating >3 cm Abundant calcification

Nodule(s)
Convex obtuse margin: ≥4 mm
Convex acute margin: Any size

Irregular or thick walls or septa
Thick: ≥4 mm Convex obtuse margin: ≤3 mm

Minimally thick walls or septa
Minimally thick: 3 mm
-and/or-
Many smooth thin septa
Many: ≥4, Thin: ≤2 mm

Few thin septa
Few: ≤3, Thin: ≤2 mm
-or-
Homogeneous nonenhancing >20HU

Simple cyst
Thin smooth wall Homogeneous Simple fluid (-9 to 20 HU) No septa or calcifications

Renal Mass Protoco l MRI and <25% enhancing tissue and no macroscopic fat

If No, then_______?

Homogeneous and T2w similar to CSF
-or-
Homogeneous and T1w fat sat SI ≥2.5x kidney

Nodule(s)
Convex obtuse margin: ≥4 mm
Convex acute margin: Any size

Irregular or thick walls or septa
Thick: ≥4 mm Convex obtuse margin: ≤3 mm

Minimally thick walls or septa
Minimally thick: 3 mm
-and/or-
Many smooth thin septa
Many: ≥4, Thin: ≤2 mm

Nonenhancing and heterogeneously hyperintense at T1w fat sat

Few thin septa
Few: ≤3, Thin: ≤2 mm
-or-
Homogeneous nonenhancing hyperintense at T1W fat sat

Simple cyst
Thin smooth wall* Homogeneous Simple fluid (like CSF) No septa or calcifications