RadteraCT Renal Mass (Multiphase Renal Protocol)
CT+ ContrastAbdomen & Pelvis
Indications
- Characterization of indeterminate renal mass (cystic vs solid, enhancement assessment, Bosniak classification)
- Suspected renal cell carcinoma — characterization and staging
- Pre-operative / pre-ablation planning (vascular anatomy, mass relationship)
- Surveillance of known renal lesion or post-treatment kidney
Patient prep
- Screen eGFR/contrast allergy; premedicate if indicated
- NPO ~2-4 h; IV access 18-20 G
- Supine, arms up; coach breath-hold
Contrast
Agentiodinated (e.g. iohexol 350 or iopamidol 370)
RouteIV
Dose≈100-125 mL at 3-4 mL/s with saline flush
TimingMultiphase: non-contrast (baseline HU), corticomedullary ~25-40 s (vascular map), nephrographic ~80-100 s (best mass detection/enhancement), +/- excretory ~5-10 min (collecting system involvement)
Technique
- Supine, arms up; non-contrast through kidneys/abdomen, post-contrast phases through kidneys (extend to abdomen/pelvis for staging)
- 120 kV; mAs per scanner with AEC; iterative reconstruction
- Thin (1.25-2 mm) source for enhancement measurement and reformats; coronal/sagittal and angiographic reformats for vascular planning
- Enhancement = increase ≥20 HU between non-contrast and post-contrast (10-20 HU indeterminate/pseudoenhancement)
- Comfortable breath-hold
Series / Sequences
| # | Series / Sequence | Plane | Thickness | Notes |
|---|---|---|---|---|
| 1 | Non-contrast axial | axial | 2.5-3 mm | Baseline HU, calcification, fat (AML) |
| 2 | Corticomedullary axial | axial | 2.5-3 mm | ~25-40 s; arterial/venous map, hypervascular mass |
| 3 | Nephrographic axial | axial | 2.5-3 mm (thin 1.25-2 mm) | ~80-100 s; best for mass detection and enhancement measurement |
| 4 | Excretory (selective) | axial | 2-3 mm | ~5-10 min; urothelial/collecting system involvement |
| 5 | Coronal/sagittal & vascular reformats | coronal | thin | Surgical/ablation planning, vascular anatomy |
Key points
- Define enhancement by HU change: ≥20 HU = true enhancement (solid/enhancing component); 10-20 HU indeterminate (consider pseudoenhancement in small/central cysts); <10-20 HU non-enhancing
- Apply Bosniak (v2019) classification for cystic masses; macroscopic fat suggests angiomyolipoma; assess for renal vein/IVC tumor thrombus
- Nephrographic phase is most sensitive for mass detection and characterization; corticomedullary aids vascular mapping but can miss medullary lesions
- Add excretory phase when collecting-system/urothelial involvement or surgical planning requires it; keep multiphase dose justified
References
• ACR–SAR–SPR Practice Parameter for the Performance of CT of the Abdomen and Pelvis (renal mass)
• Bosniak Classification v2019 (Silverman et al., Radiology 2019); ACR Appropriateness Criteria: Indeterminate Renal Mass
• Radiopaedia: CT renal mass / dedicated renal protocol link
• RadioGraphics: Multiphasic CT of Renal Masses
• Bosniak Classification v2019 (Silverman et al., Radiology 2019); ACR Appropriateness Criteria: Indeterminate Renal Mass
• Radiopaedia: CT renal mass / dedicated renal protocol link
• RadioGraphics: Multiphasic CT of Renal Masses
Source: Researched — verify against your institution
Reference template — verify and adapt to your scanner, vendor and institution before clinical use. Not a substitute for clinical judgment.