Laboratory coherent-scatter analysis of intact urinary stones with crystalline composition: a tomographic approach

High-energy X-ray diffraction experiment employing a compact synchrotron X-ray source based on inverse Compton scattering

X-ray diffraction (XRD) is an important material analysis technique with a widespread use of laboratory systems. These systems typically operate at low X-ray energies (from 5 keV to 22 keV) since they rely on the small bandwidth of K-lines like copper. The narrow bandwidth is essential for precise measurements of the crystal structure in these systems. Inverse Compton X-ray source (ICS) could pave the way to XRD at high X-ray energies in a laboratory setting since these sources provide brilliant energy-tunable and partially coherent X-rays. This study demonstrates high-energy XRD at an ICS with strongly absorbing mineralogical samples embedded in soft tissue. A quantitative comparison of the measured XRD patterns with calculations of their expected shapes validates the performance of ICSs for XRD. This analysis was performed for two types of kidney stones of different materials. Since these stones are not isolated in a human body, the influence of the surrounding soft tissue on the XRD pattern is investigated and a correction for this soft tissue contribution is introduced.

Development and assessment of an x-ray tube-based multi-beam x-ray scatter projection imaging system

Coherent scatter x-ray imaging systems are sensitive to material structure and chemical composition, and generate soft-material images with contrast superior to conventional transmission x-ray imaging. For practicality in medical or security applications, the image data acquisition time should be <10 min. Our approach is a multi-beam projection imaging design. Previously, as a development stage, we implemented a synchrotron-based system with five coplanar pencil beams and continuous motion of the object. In the work reported here, we developed a more practical coherent scatter projection imaging system using a conventional x-ray tube source. The object is irradiated by an array of up to three rows by five columns of pencil beams, and motorized stages translate the object through the beams for step-and-shoot acquisition. For the same tube loading, broad spectrum beams, such as 110 kVp filtered with 2.25 mm Al, were found to provide a higher signal-difference-to-noise ratio between soft materials in scatter images than lower kVp, more heavily filtered beams that have a narrower, lower intensity spectrum. The shortest acquisition time for a 6.0 × 10.0 cm² object with 6000 pixels was 8.8 min. The width of a sharp edge in the scatter image was consistent with the pencil beam diameter. Contrast-detail performance was similar to our synchrotron-based system. In this first x-ray tube-based system, for simplicity, the transmitted x rays are measured through attenuators using the same flat-panel detector that measures scattered x rays. As a result, the primary image quality was reduced.

Chemical composition and binary mixture of human urinary stones using FT-Raman spectroscopy method

In the present study the human urinary stones were observed in their different chemical compositions of calcium oxalate monohydrate, calcium oxalate dihydrate, calcium phosphate, struvite (magnesium ammonium phosphate), uric acid, cystine, oxammite (ammonium oxalate monohydrate), natroxalate (sodium oxalate), glushinkite (magnesium oxalate dihydrate) and moolooite (copper oxalate) were analyzed using Fourier Transform-Raman (FT-Raman) spectroscopy. For the quantitative analysis, various human urinary stone samples are used for ratios calculation of binary mixtures compositions such as COM/COD, HAP/COD, HAP/COD, Uric acid/COM, uric acid/COD and uric acid/HAP. The calibration curve is used for further analysis of binary mixture of human urinary stones. For the binary mixture calculation the various intensities bands at 1462 cm(-1) (I(COM)), 1473 cm(-1) (I(COD)), 961 cm(-1) (I(HAP)) and 1282 cm(-1) (I(UA)) were used.

Snapshot 2D tomography via coded aperture x-ray scatter imaging

This paper describes a fan beam coded aperture x-ray scatter imaging system that acquires a tomographic image from each snapshot. This technique exploits the cylindrical symmetry of the scattering cross section to avoid the scanning motion typically required by projection tomography. We use a coded aperture with a harmonic dependence to determine range and a shift code to determine cross range. Here we use a forward-scatter configuration to image 2D objects and use serial exposures to acquire tomographic video of motion within a plane. Our reconstruction algorithm also estimates the angular dependence of the scattered radiance, a step toward materials imaging and identification.

FT-Raman spectral analysis of human urinary stones

FT-Raman spectroscopy is the most useful tool for the purpose of bio-medical diagnostics. In the present study, FT-Raman spectral method is used to investigate the chemical composition of urinary calculi. Urinary calculi multi-components such as calcium oxalate, hydroxyl apatite, struvite and uric acid are studied. FT-Raman spectrum has been recorded in the range of 3500-400 cm(-1). Chemical compounds are identified by Raman spectroscopic technique. The quantitative estimations of calcium oxalate monohydrate (COM) 1463 cm(-1), calcium oxalate dehydrate (COD) 1478 cm(-1), hydroxyl apatite 959 cm(-1), struvite 575 cm(-1), uric acid 1283 cm(-1) and oxammite (ammonium oxalate monohydrate) 2129 cm(-1) are calculated using particular peaks of FT-Raman spectrum. The quantitative estimation of human urinary stones suitable for the single calibration curve was performed.

FT-IR spectral studies on certain human urinary stones in the patients of rural area

Fourier transform infrared spectroscopy (FT-IR) has been carried out to analyze the organic and inorganic constituent of human urinary stones. Patient's hailing from Rajah Muthiah Medical College and Hospital, Annamalai University, Tamil Nadu, India was selected for the study. The FT-IR results indicate that stones have different composition, i.e., namely calcium oxalate, calcium phosphate, carbonate apatite and magnesium ammonium phosphate and uric acid. From the spectral and powder X-ray diffraction pattern, the chemical constituents of urinary stones were identified. The quantitative estimations of calcium oxalate monohydrate (COM) 1,620 cm(-1), calcium phosphate (apatite) 1,037 cm(-1), magnesium ammonium phosphate (struvite) 1,010 cm(-1), calcium carbonate 1,460 cm(-1) and uric acid 1,441 cm(-1) were calculated using particular peaks of FT-IR studies. The study reveals that calcium oxalate monohydrate and calcium phosphate type urinary stones were predominant whereas magnesium ammonium phosphate are in moderate level, and calcium carbonate and uric acid are in low. Calcium phosphate is found in all the stones and calcium oxalate monohydrate is found to be higher. Quantitative analyses of urinary stones show that calcium oxalate monohydrate (40%), apatite (30%), magnesium ammonium phosphate (23%) and uric acid (7%) are present in all the urinary stone samples.

Investigation of the microstructure and mineralogical composition of urinary calculi fragments by synchrotron radiation X-ray microtomography: a feasibility study

The outcomes from the feasibility study on utilization of synchrotron radiation X-ray microtomography (SR-μCT) to investigate the texture and the quantitative mineralogical composition of selected calcium oxalate-based urinary calculi fragments are presented. The comparison of the results obtained by SR-μCT analysis with those derived from current standard analytical approaches is provided. SR-μCT is proved as a potential effective technique for determination of texture, 3D microstructure, and composition of kidney stones.

Characterization and FTIR spectral studies of human urinary stones from Southern India

Urinary stones resected from urinary bladders of patients hailing from Kollam district of Kerala State, India were analyzed by SEM, XRD and by thermal analysis techniques. The analytical results indicate that, stones have different composition, i.e., calcium phosphate, calcium phosphate hydroxide and sodium calcium carbonate. Infrared spectral studies also reveal the presence of phosphates or carbonates in these samples. Further, IR spectral investigations have revealed that amorphous carbonated species are occupied in PO(4) sites in calcium phosphate type stone and OH sites in calcium phosphate hydroxide sample. Thermal studies of these samples also reveal that, carbon dioxide is released from carbonated samples upon heating which is related to amount of carbon content and bond strength. Crystals with defects and irregular morphology are grown inside the urinary bladder due to variation in crystal growth conditions.

Imaging modalities for urolithiasis: impact on management

PURPOSE OF REVIEW

Urolithiasis is a common urological problem, often requiring efficient workup, accurate diagnosis, and treatment. The purpose of this review is to summarize the imaging modalities employed for the diagnosis of calculi and the caveats of different clinical situations.

RECENT FINDINGS

Noncontrast computed tomography has become the most universally used imaging tool for diagnosing urolithiasis, although ultrasound and magnetic resonance imaging maintain specific roles. Noncontrast computed tomography may provide prognostic information regarding the success of specific management strategies for urolithiasis. Additionally, noncontrast computed tomography is being tested in lower-radiation dose protocols with promising results.

SUMMARY

Considering the well supported accuracy and relative ease of use of noncontrast computed tomography, it has become a logical choice for the urologist to use the technique as a diagnostic tool for stone disease. The future of imaging for intervention and surveillance of stone disease lies in the continued progress of noncontrast computed tomography in terms of patient safety. This will need to be done by developing low-dose radiation computed tomography that can replicate the efficacy of current noncontrast computed tomography.

A CMOS active pixel sensor system for laboratory- based x-ray diffraction studies of biological tissue

X-ray diffraction studies give material-specific information about biological tissue. Ideally, a large area, low noise, wide dynamic range digital x-ray detector is required for laboratory-based x-ray diffraction studies. The goal of this work is to introduce a novel imaging technology, the CMOS active pixel sensor (APS) that has the potential to fulfil all these requirements, and demonstrate its feasibility for coherent scatter imaging. A prototype CMOS APS has been included in an x-ray diffraction demonstration system. An industrial x-ray source with appropriate beam filtration is used to perform angle dispersive x-ray diffraction (ADXRD). Optimization of the experimental set-up is detailed including collimator options and detector operating parameters. Scatter signatures are measured for 11 different materials, covering three medical applications: breast cancer diagnosis, kidney stone identification and bone mineral density calculations. Scatter signatures are also recorded for three mixed samples of known composition. Results are verified using two independent models for predicting the APS scatter signature: (1) a linear systems model of the APS and (2) a linear superposition integral combining known monochromatic scatter signatures with the input polychromatic spectrum used in this case. Cross validation of experimental, modelled and literature results proves that APS are able to record biologically relevant scatter signatures. Coherent scatter signatures are sensitive to multiple materials present in a sample and provide a means to quantify composition. In the future, production of a bespoke APS imager for x-ray diffraction studies could enable simultaneous collection of the transmitted beam and scattered radiation in a laboratory-based coherent scatter system, making clinical transfer of the technique attainable.