Dual-energy computed tomography with advanced postimage acquisition data processing: improved determination of urinary stone composition.
BACKGROUND
The characterization of urinary calculi using noninvasive methods has the potential to affect clinical management. CT remains the gold standard for diagnosis of urinary calculi, but has not reliably differentiated varying stone compositions. Dual-energy CT (DECT) has emerged as a technology to improve CT characterization of anatomic structures. This study aims to assess the ability of DECT to accurately discriminate between different types of urinary calculi in an in vitro model using novel postimage acquisition data processing techniques.


METHODS
Fifty urinary calculi were assessed, of which 44 had >or=60% composition of one component. DECT was performed utilizing 64-slice multidetector CT. The attenuation profiles of the lower-energy (DECT-Low) and higher-energy (DECT-High) datasets were used to investigate whether differences could be seen between different stone compositions.


RESULTS
Postimage acquisition processing allowed for identification of the main different chemical compositions of urinary calculi: brushite, calcium oxalate-calcium phosphate, struvite, cystine, and uric acid. Statistical analysis demonstrated that this processing identified all stone compositions without obvious graphical overlap.


CONCLUSIONS
Dual-energy multidetector CT with postprocessing techniques allows for accurate discrimination among the main different subtypes of urinary calculi in an in vitro model. The ability to better detect stone composition may have implications in determining the optimum clinical treatment modality for urinary calculi from noninvasive, preprocedure radiological assessment.
Ferrandino
Michael N
MN
Division of Urology, Duke University Medical Center, Durham, North Carolina 27710, USA. michael.ferrandino@duke.edu
Pierre
Sean A
SA
Simmons
Walter Neal
WN
Paulson
Erik K
EK
Albala
David M
DM
Preminger
Glenn M
GM
D000704:Analysis of Variance; D006801:Humans; D017711:Nonlinear Dynamics; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014545:Urinary Calculi / Q000737:chemistry* / Q000000981:diagnostic imaging*