Comparing non contrast computerized tomography criteria versus dual X-ray absorptiometry as predictors of radio-opaque upper urinary tract stone fragmentation after electromagnetic shockwave lithotripsy

Abstract

The objective of this study was to assess the value of dual X-ray absorptiometry (DXA) in comparison to non contrast computed tomography (NCCT) density as possible predictors of upper urinary tract stone disintegration by shock wave lithotripsy (SWL). This study included 100 consecutive patients, with solitary renal stone 0.5-2 cm or upper ureteral stone up to 1 cm. DXA to calculate stone mineral density (SMD) and stone mineral content (SMC) was done. NCCT was performed to measure Hounsfield units (HU). SWL was performed with an electromagnetic lithotripsy, plain X-ray documented disintegration after SWL. Successful treatment was defined as stone free or complete fragmentation after 1 or 2 sessions of SWL. The impact of patients age, sex, body mass index, stone laterality, location, volume, length, mean SMC and SMD, HU and Hounsfield density (HD), skin to stone distance (SSD) and number of shock waves were evaluated by univariate and multivariate analysis. Only 76 patients were available for follow-up. Success of disintegration was observed in 50 out of 76 patients (65.8 %). On multivariate analysis, SMC and number of shock wave were the significant independent factors affecting SWL outcome (p = 0.04 and p = 0.000, respectively). SMC as detected by DXA is a significant predictor of success of stone disintegration by SWL. SMC measured by DXA is more accurate than HU measured by CT. Patients with high stone mineral content (SMC greater than 0.65 g) should be directly offered another treatment option.

Clinical Nomograms to Predict Stone-Free Rates after Shock-Wave Lithotripsy: Development and Internal-Validation

“…Consistent with previous studies [ 9 – 11 , 17 , 18 , 22 ], HU was a significant predictor of SFR after SWL in a multivariate analysis in our study. On the other hand, whether HN has an effect on the treatment outcome of SWL is controversial [ 23 , 24 ].…”

“…Despite the numerous studies and great efforts to discover factors related to SWL outcomes [ 7 , 9 , 11 , 17 – 22 ], a clear general consensus has yet to be reached. Kanao et al [ 6 ] developed a nomogram to predict lithotripsy success based on stone size, location, and the degree of stone burden.…”

“…CT imaging is considered the gold standard for diagnosing urolithiasis due to its high specificity and sensitivity [ 7 , 17 ], and in current clinical setting, there is an increasing trend of performing CT scans. In the present study, we therefore analyzed CT-based stone parameters in combination with clinical information.…”

Predictive Value of Hounsfield Unit, Volumetric Stone Burden in Fragmentation and Specific Composition of Urinary Calculi

“…[7] Hameed et al reported that successful outcome of ESWL was decreased in calculus with HU > 1350 and required application of more shock waves. [8] A study by Massoud et al reported that patients with Stone attenuation value (SAV) of > 956HU were not ideal candidate and SAV was an independent predictor of ESWL outcome. [9] Bandi et al found VSB to be strongest predictor of ESWL outcome in multivariate analysis (p< 0.001) in their study of patients with upper urinary tract calculi.…”

Peeling the Otolith of Fish: Optimal Parameterization for Micro-CT Scanning

“…Mapp et al (2016) and FAbOSA group (2002) did not present HU values. Nevertheless, other calcified structures are out of this range, e.g., scallop shells (744 HU) (Diez et al, 2013) and ureteral stone (1,350 HU) (Hameed et al, 2013).…”