What this calculator does
Organizes renal mass MRI features into the five-point clear cell likelihood score.
Enter the lesion's signal, enhancement, diffusion, and fat-related MRI features.
Clinical scope
Use ccLS to estimate the likelihood that an indeterminate, predominantly solid, enhancing renal mass without macroscopic fat represents clear cell renal cell carcinoma on multiparametric MRI. The original clinical context emphasized small renal masses.
Applicability and exclusions
- Do not apply the score to a mass with macroscopic fat, a predominantly cystic mass, or a lesion with less than the required enhancing solid tissue.
- ccLS estimates subtype likelihood; it is not a Bosniak category, pathologic diagnosis, stage, grade, or management recommendation.
Method and calculation logic
The algorithm first checks macroscopic fat and adequate enhancement, then evaluates T2 signal and corticomedullary enhancement. Microscopic fat, segmental enhancement inversion, diffusion restriction, and enhancement behavior refine the five-point likelihood score.
Interpretation table
| Score | Likelihood of clear cell RCC |
|---|---|
| 1 | Very unlikely |
| 2 | Unlikely |
| 3 | Indeterminate / equivocal |
| 4 | Likely |
| 5 | Highly likely |
Worked example
Case: Fictional example: a 3 cm solid enhancing renal mass has no macroscopic fat, is T2 hyperintense, and shows intense corticomedullary enhancement without a downgrade feature.
Calculation: Confirm eligibility, then follow the T2 signal and corticomedullary enhancement branches and enter any refinement features.
Interpretation: A high ccLS supports a higher likelihood of clear cell RCC but does not replace histopathology or multidisciplinary management.
How to use this calculator
- Complete the visible imaging and measurement fields. Required inputs are marked in the workbench.
- Review the calculated category, score, measurements, and any recommendation or warning.
- Copy the report-ready text only after checking the result against the complete examination and source guideline.
Calculator-specific questions
What population was ccLS developed for?
It was developed for indeterminate solid enhancing renal masses on multiparametric MRI, with much of the evidence centered on small renal masses and exclusion of macroscopic fat.
Does ccLS diagnose clear cell RCC?
No. It provides an imaging likelihood category. Histopathology remains the reference standard when tissue diagnosis is required.
Are patient measurements sent to RadPhrases?
No. Calculator inputs and results are processed in the browser and are not submitted by this page.