Relationship Between Abdominal Non-contrast CT Scan Hounsfield Unit Value with Stone Composition Analysis in Kidney Stone Patients

Dhirajaya Dharma Kadar; Ginanda Putra Siregar

Volume : VIII, Issue : X, October - 2019

Relationship Between Abdominal Non-contrast CT Scan Hounsfield Unit Value with Stone Composition Analysis in Kidney Stone Patients

Dhirajaya Dharma Kadar, Ginanda Putra Siregar

Abstract :

Introduction: Hounsfield unit (HU) is used to indicate the radiodensity of urinary stones. Our study aims to describe the relationship between HU with urinary stone. Material Methods: A retrospective cross-sectional study was conducted with thirty patients with kidney stones that have examined with NCCT. Results: The mean age of patients was 51.0 + 10.4 years, with 15 patients were male (50%), and 15 others were female (50%). The median value of HU level was 661 (range 200-1499). Thirty patients in our study, 16 stones (53.3%) were composed calcium, while 14 others (46.7%), were composed mostly of uric acid. ROC analysis that HU criteria to predict stone composition have sensitivity 71,4% specificity 87,5% PPV 83.33% and NPV 77.78%. Conclusion: The threshold of 500 HU on the CT scan determined as the optimal cut-off point in deciding whether a urinary stone composition is predominantly calcium stone or uric acid stone.