CT KUB in Renal Cysts

Renal cysts are among the most frequently encountered incidental findings(1) on abdominal imaging, particularly with the increasing use of cross-sectional imaging. Most simple cysts are benign and require no further evaluation.

However, complex cystic lesions pose a diagnostic challenge, necessitating accurate characterization to distinguish benign from malignant lesions.(2).

While CT KUB is highly effective for detecting urinary tract stones, there are several limitations and pitfalls we should be aware of as Limited Soft Tissue Assessment as without contrast, masses, infections, or vascular lesions may not be clearly visible also some tumors called isodensity tumors, have similar intensity values to the surrounding normal tissues.(3).

Segmentation of kidney tumors on CT KUB images adds challenges compared to contrast-enhanced CT (CECT) images, due to low contrast and lack of multiphase images. On CECT images, the kidney tumors have different intensity values compared to the normal tissues.(4).

Validating CT KUB's accuracy in assessing renal cysts could have significant implications for clinical decision making, especially in resource-limited or urgent care settings

• CT scan (Device), also known as Ultrasound: All Patients will undergo CT KUB cyst evaluation Qualitatively regarding Gross Picture in Imaging and Quantitavely using Hausfield units then patients will undergo Abdomianl ultrasound

Primary outcomes

• Validiation of CT KUB results in assesment of Renal Cystic Lesions prospectively in comparison to Ultrasonographic as in terms of Sensitivity and Specificity regarding evalution of Cystic lesion complexity according to Bosniak Classification [From Time of CT KUB referal till accurate diagnosis of Cystic lesion up to 24 weeks]: CT KUB cyst evaluation Qualitatively as Gross Picture and Quantitavely using Hausfield units then Abdomianl ultrasound , otherwise Bosniak I Renal cysts will undergo further assessment contrast-enhanced CT then Follow Up or Histopathology Data will be captured on a pre-piloted electronic case report form with de-identified study codes. Statistical analysis (sensitivity, specificity, PPV, NPV, accuracy, ROC/AUC) and inter-/intra-observer agreement (κ/ICC) will be conducted using SPSS/R/Stata. Quality assurance will follow institutional scanner QA logs, a priori reader calibration, and an audit-trailed database.

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Patients referred for CT KUB with detectable Renal cysts

Exclusion Criteria:

* 1-Patients with known renal tumors.
* 2-Inadequate imaging quality: CT KUB with severe motion/streak artifact or incomplete anatomical coverage preventing lesion assessment.

• Forookhi, A., Bicchetti, M., Lucciola, S. et al. The thin line that made the difference: a case report on a Bosniak IIF renal cystic mass treated with cyst decortication. Egypt J Radiol Nucl Med 53, 115 (2022). https://doi.org/10.1186/s43055-022-00791-3
• Smith AD, Remer EM, Cox KL, Lieber ML, Allen BC, Shah SN, Herts BR. Bosniak category IIF and III cystic renal lesions: outcomes and associations. Radiology. 2012 Jan;262(1):152-60. doi: 10.1148/radiol.11110888. Epub 2011 Nov 21. PMID 22106359