Renal stone characterization using high resolution imaging mode on a photon counting detector CT system

In addition to the standard-resolution (SR) acquisition mode, a high-resolution (HR) mode is available on a research photon-counting-detector (PCD) whole-body CT system. In the HR mode each detector consists of a 2x2 array of 0.225 mm x 0.225 mm subpixel elements. This is in contrast to the SR mode that consists of a 4x4 array of the same subelements, and results in 0.25 mm isotropic resolution at iso-center for the HR mode. In this study, we quantified ex vivo the capabilities of the HR mode to characterize renal stones in terms of morphology and mineral composition. Forty pure stones - 10 uric acid (UA), 10 cystine (CYS), 10 calcium oxalate monohydrate (COM) and 10 apatite (APA) - and 14 mixed stones were placed in a 20 cm water phantom and scanned in HR mode, at radiation dose matched to that of routine dual-energy stone exams. Data from micro CT provided a reference for the quantification of morphology and mineral composition of the mixed stones. The area under the ROC curve was 1.0 for discriminating UA from CYS, 0.89 for CYS vs COM and 0.84 for COM vs APA. The root mean square error (RMSE) of the percent UA in mixed stones was 11.0% with a medium-sharp kernel and 15.6% with the sharpest kernel. The HR showed qualitatively accurate characterization of stone morphology relative to micro CT.

[1]  Baiyu Chen,et al.  Evaluation of conventional imaging performance in a research whole-body CT system with a photon-counting detector array , 2016, Physics in medicine and biology.

[2]  J. Schlomka,et al.  Experimental feasibility of multi-energy photon-counting K-edge imaging in pre-clinical computed tomography , 2008, Physics in medicine and biology.

[3]  Jiang Hsieh,et al.  Computed Tomography: Principles, Design, Artifacts, and Recent Advances, Fourth Edition , 2022 .

[4]  K. Taguchi,et al.  Vision 20/20: Single photon counting x-ray detectors in medical imaging. , 2013, Medical physics.

[5]  Shuai Leng,et al.  Dual-Energy CT for Quantification of Urinary Stone Composition in Mixed Stones: A Phantom Study. , 2016, AJR. American journal of roentgenology.

[6]  Shuai Leng,et al.  Dual-energy dual-source CT with additional spectral filtration can improve the differentiation of non-uric acid renal stones: an ex vivo phantom study. , 2011, AJR. American journal of roentgenology.

[7]  C H McCollough,et al.  Novel ultrahigh resolution data acquisition and image reconstruction for multi-detector row CT. , 2007, Medical physics.

[8]  Polad M Shikhaliev Photon counting spectral CT: improved material decomposition with K-edge-filtered x-rays. , 2012, Physics in medicine and biology.

[9]  P. Shikhaliev Computed tomography with energy-resolved detection: a feasibility study , 2008, Physics in medicine and biology.

[10]  S Leng,et al.  Temporal Bone CT: Improved Image Quality and Potential for Decreased Radiation Dose Using an Ultra-High-Resolution Scan Mode with an Iterative Reconstruction Algorithm , 2015, American Journal of Neuroradiology.

[11]  M. Reiser,et al.  Dual Energy CT Characterization of Urinary Calculi: Initial In Vitro and Clinical Experience , 2008, Investigative radiology.

[12]  Richard H Cohan,et al.  Dual-energy CT with single- and dual-source scanners: current applications in evaluating the genitourinary tract. , 2012, Radiographics : a review publication of the Radiological Society of North America, Inc.

[13]  Polad M Shikhaliev,et al.  Photon counting multienergy x-ray imaging: effect of the characteristic x rays on detector performance. , 2009, Medical physics.

[14]  J. Iwanczyk,et al.  Photon Counting Energy Dispersive Detector Arrays for X-ray Imaging , 2007, IEEE Transactions on Nuclear Science.

[15]  D. Maeding,et al.  Preliminary results obtained from a novel CdZnTe pad detector and readout ASIC developed for an automatic baggage inspection system , 2000, 2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149).

[16]  C. McCollough,et al.  Characterization of Urinary Stone Composition by Use of Third-Generation Dual-Source Dual-Energy CT With Increased Spectral Separation. , 2015, AJR. American journal of roentgenology.

[17]  P. Shikhaliev,et al.  Photon counting spectral CT versus conventional CT: comparative evaluation for breast imaging application , 2011, Physics in medicine and biology.

[18]  Edgar Kraft,et al.  A research prototype system for quantum-counting clinical CT , 2010, Medical Imaging.

[19]  Hatem Alkadhi,et al.  In vivo identification of uric acid stones with dual-energy CT: diagnostic performance evaluation in patients , 2010, Abdominal Imaging.

[20]  Willi A. Kalender,et al.  Computed tomography : fundamentals, system technology, image quality, applications , 2000 .

[21]  A Halaweish,et al.  A high-resolution imaging technique using a whole-body, research photon counting detector CT system , 2016, SPIE Medical Imaging.

[22]  James E Lingeman,et al.  Nondestructive analysis of urinary calculi using micro computed tomography , 2004, BMC urology.

[23]  M. Reiser,et al.  Dual Energy CT Characterization of Urinary Calculi: Initial In Vitro and Clinical Experience , 2008, Investigative radiology.

[24]  Rainer Raupach,et al.  Spatial resolution improvement and dose reduction potential for inner ear CT imaging using a z-axis deconvolution technique. , 2013, Medical physics.

[25]  E. Nygard,et al.  Photon counting energy dispersive detector arrays for x-ray imaging , 2007, 2007 IEEE Nuclear Science Symposium Conference Record.