Low-dose characterization of kidney stones using spectral detector computed tomography: an ex vivo study
Objectives - The aim of this study was to investigate the feasibility of kidney stone composition analysis using spectral detector computed tomography scanner (SDCT) with normal- and low-dose imaging protocols. - Methods - A total of 154 stones harvested from nephrolithotripsy or nephrolitho...
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| Main Authors: | , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
August 2018
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| In: |
Investigative radiology
Year: 2018, Volume: 53, Issue: 8, Pages: 457-462 |
| ISSN: | 1536-0210 |
| DOI: | 10.1097/RLI.0000000000000468 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1097/RLI.0000000000000468 Verlag, lizenzpflichtig, Volltext: https://journals.lww.com/investigativeradiology/Fulltext/2018/08000/Low_Dose_Characterization_of_Kidney_Stones_Using.3.aspx 
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| Author Notes: | Nils Große Hokamp, Johannes Salem, Albrecht Hesse, Jasmin Alexandra Holz, Manuel Ritter, Axel Heidenreich, David Maintz, and Stefan Haneder |
| Summary: | Objectives - The aim of this study was to investigate the feasibility of kidney stone composition analysis using spectral detector computed tomography scanner (SDCT) with normal- and low-dose imaging protocols. - Methods - A total of 154 stones harvested from nephrolithotripsy or nephrolithotomy with a known monocrystalline composition as determined by infrared spectroscopy were examined in a nonanthropomorphic phantom on an SDCT (IQon, Philips, Best, the Netherlands). Imaging was performed with 120 kVp and (a) 40 mAs and (b) 200 mAs, resulting in a computed tomography dose index (CTDIvol) of 2 and 10 mGy, respectively. Besides conventional CT images (CIs), SDCT enables reconstruction of virtual monoenergetic images (40-200 keV). Spectral coefficient images were calculated by performing a voxel-by-voxel combination of 40 and 200 keV images (Matlab R2017b, Mathworks Inc). All stones were semiautomatically 3D-segmented on CI using a threshold-based algorithm implemented in an offline DICOM viewer. Statistical assessment was performed using Steel-Dwass method to adjust for multiple comparisons. - Results - Ca-phosphate (n = 22), Ca-oxalate (n = 82), cysteine (n = 20), struvite (n = 3), uric acid (n = 18), and xanthine stones (n = 9) were included in the analysis. Stone diameter ranged from 3.0 to 13.5 mm. On CI, attenuation differed significantly between calcific and noncalcific stones only (P ≤ 0.05), the spectral coefficient differed significantly between (//): Ca-oxalate//Ca-phosphate//cystine//struvite//uric acid//xanthine in 10 mGy protocol (all P ≤ 0.05). The same results were found for the 2 mGy-protocol, except that differentiation of Ca-oxalate and Ca-phosphate as well as uric acid and xanthine was not possible (P ≥ 0.05). - Conclusions - Spectral detector CT allows for differentiation of kidney stones using semi-automatic segmentation and advanced image post-processing, even in low-dose imaging protocols. |
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| Item Description: | Gesehen am 10.02.2021 |
| Physical Description: | Online Resource |
| ISSN: | 1536-0210 |
| DOI: | 10.1097/RLI.0000000000000468 |