image: Axial CT images in the (A) unenhanced, (B) corticomedullary, and (C) nephrographic phases at the same level depict the mass (arrow, A and C), which shows avid heterogeneous enhancement. Circular ROIs were placed in the most enhancing component of the mass and in ipsilateral renal cortex (circles, B), to determine the mass-to-cortex corticomedullary attenuation ratio. Heterogeneity scores were assigned subjectively using a 5-point Likert type-scale. These two features were used to inform development of the CT score. In this patient, the mass showed avid enhancement (mass-to-cortex corticomedullary enhancement ratio >0.75) and was considered completely heterogeneous (heterogeneous score, 5) by both radiologists, resulting in CT score 5. Nephrectomy revealed clear-cell renal cell carcinoma. view more
Credit: American Roentgen Ray Society (ARRS), American Journal of Roentgenology (AJR)
Leesburg, VA, June 29, 2022—According to ARRS’ American Journal of Roentgenology (AJR), a 5-tiered CT scoring algorithm may represent a clinically useful tool for diagnosis of clear-cell renal cell carcinoma (RCC) in small (≤4 cm) solid renal masses.
“A 5-tiered renal CT algorithm, including mass-to-cortex corticomedullary attenuation ratio and heterogeneity score, had substantial inter-observer agreement, moderate AUC and PPV, and high NPV for diagnosing clear-cell RCC,” concluded Nicola Schieda from the department of medical imaging at Canada’s Ottawa Hospital.
Schieda and colleagues’ study included 148 patients (mean age, 58 years; 73 men, 75 women) with 148 small (≤4 cm) solid (>25% enhancing tissue) renal masses that underwent renal-mass CT (unenhanced, corticomedullary, and nephrographic phases) before resection between January 2016 and December 2019. Two radiologists independently evaluated CT examinations and recorded calcification, mass attenuation in all phases, mass-to-cortex corticomedullary attenuation ratio, and heterogeneity score (5-point Likert scale, assessed in corticomedullary phase).
Ultimately, Schieda et al’s 5-tiered CT scoring algorithm—including mass-to-cortex corticomedullary attenuation ratio and heterogeneity score—had substantial interobserver agreement (weighted kappa=0.71) and achieved AUC for diagnosing clear-cell RCC of 0.75 (95% CI, 0.68-0.82) for reader 1 and 0.72 (95% CI, 0.66-0.82) for reader 2.
“If validated,” the authors of this AJR article acknowledged, “the CT algorithm may represent a useful clinical tool for diagnosing clear-cell renal cell carcinoma."
North America’s first radiological society, the American Roentgen Ray Society (ARRS) remains dedicated to the advancement of medicine through the profession of medical imaging and its allied sciences. An international forum for progress in radiology since the discovery of the x-ray, ARRS maintains its mission of improving health through a community committed to advancing knowledge and skills with the world’s longest continuously published radiology journal—American Journal of Roentgenology—the ARRS Annual Meeting, InPractice magazine, topical symposia, myriad multimedia educational materials, as well as awarding scholarships via The Roentgen Fund®.
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Journal
American Journal of Roentgenology
Method of Research
Imaging analysis
Subject of Research
People
Article Title
Development of a Multiparametric Renal CT Algorithm for Diagnosis of Clear-Cell Renal Cell Carcinoma Among Small (≤4 cm) Solid Renal Masses
Article Publication Date
29-Jun-2022
COI Statement
No disclosures