Scintillator Screen Research Articles

Stable Organic‐Inorganic Hybrid Sb(III) Halide Scintillator for Nonplanar Ultra‐Flexible X‐Ray Imaging

AbstractFlexible scintillator screens with excellent stability and low detection limits are crucial for X‐ray imaging applications. 0D organic metal halide materials have emerged as a strong contender in the scintillator fields, owing to their excellent optical characteristics and simple maneuverability. Herein, high‐quality and large quantities of C38H36P2Sb2Cl8 single crystals are synthesized through a simple solution approach. The prepared single crystals with dimer‐structure [Sb2Cl8]2− exhibit yellow emission with a near‐unity high photoluminescence quantum yield (PLQY) of 99.8%, and possess an exceptional light yield of 41300 photons MeV−1, and a detection limit as low as 45.6 nGyair s−1. On this basis, a large‐size and ultra‐flexible C38H36P2Sb2Cl8 scintillator utilized for X‐ray imaging is prepared by template assembled method, demonstrating a high spatial resolution of 8.15 lp mm−1. The prepared ultra‐flexible scintillator screen can achieve excellent X‐ray imaging even after multiple bending and stretching, which can also provide clear non‐planar X‐ray imaging for irregular objects. In addition, the scintillator shows excellent stability in light, heat, X‐ray irradiation, and water. These results not only expand the optoelectronic application field of organic‐inorganic hybrid antimony halides but also promote the rapid development of efficient ultra‐flexible scintillators.

Benefits of front coating crystalline scintillator screens for phase-contrast synchrotron micro-tomography

Transparent crystalline scintillators such as cerium-doped YAG or LuAG are widely used in X-ray imaging for the indirect detection of X-rays. The application of reflective coatings on the front side to improve the optical gain is common practice for flat panel detectors with CsI or Gd2O2S powder scintillators but still largely unknown for crystalline scintillators such as LuAG. This work shows experimentally and quantitatively how a black and reflective coating on the X-ray side of a 2 mm LuAG:Ce scintillator improves the image quality compared to a 2 mm LuAG:Ce scintillator without a coating. The measurements have been done for two different distances, with 2 m and 29.7 m on the BM18 beamline of the European Synchrotron. The Modulation Transfer Function (MTF) and the Signal-to-Noise-Ratio (SNR2) power spectrum as well as contrast-to-noise ratio are used for comparing image quality. Propagation-based phase contrast strongly enhances the SNR2 amplitudes (gain ≈10 from 2 m to 29.7 m object-detector distance) of the raw images’ spectrum independent of the scintillator coating. For both detector positions, the reflective coating is able to raise SNR2 by up to 80% through the improved optical gain, while black coating does the opposite (decrease SNR2 by 20%) with respect to no coating. With the tested optical setups, changes in MTF /sharpness between the coatings are minor. Comparing CNR2 in CT scans of a multi-material sample, in this case an electric motor, we observe the reflective coating yielding better material contrast for plastic and air. Application and effect of Wiener-deconvolution, along with Paganin-type phase retrieval, are also discussed in the context of CT image quality.

Rod‐Like Microcrystal Scintillators Based on Organic–Inorganic Hybrid Copper Halides for X‐Ray Imaging

AbstractCopper‐based organic–inorganic hybrid halides (OIHHs) have garnered significant interest in X‐ray imaging due to their flexible structural adjustability, efficient light emission, strong X‐ray absorption, etc. Herein, four copper‐based OIHH crystals composed of the same organic ligands (isopropyl triphenylphosphonium cations, IPP+) and inorganic parts (Cu2I42−) are synthesized by varying the ratios of raw materials and types of reaction solvents. Although these crystals share identical structures, they exhibit different luminescent behaviors (blue, green, white, and yellow) attributed to vacancy defects originating from CuI. Notably, the novel copper‐based OIHH (CP2) with green emission shows the best luminescence efficiency (99.54%) and excellent scintillation performance (50675 photons MeV−1). The traditional technology of scintillation screens mixing scintillator powders and polymers often results in light scattering due to powder aggregation and inhomogeneity. To address this challenge, the dispersant polyvinyl pyrrolidone is introduced to prepare uniform rod‐like microcrystals of CP2. The scintillation screen based on CP2 microcrystals achieves a high spatial resolution of 16–18 lp mm−1, surpassing the resolution of most copper‐based OIHH scintillators. Furthermore, it is imaging capabilities are validated using a commercial X‐ray flat panel detector, demonstrating imaging performance comparable to that of commercial scintillators.

Enhancing low-energy X-ray excited afterglow in lanthanide-doped fluoride core@shell nanoparticles for autofluorescence-free imaging

Lanthanide-doped fluoride nanoparticles (NPs) exhibit tunable X-ray excited afterglow (XEA), holding great promise for autofluorescence-free flexible X-ray imaging. However, materials with low atomic numbers, while sensitive to low-energy X-ray photons, suffer from weak X-ray absorption coefficients. This poses a significant challenge in achieving high-performance XEA with minimized radiation risk. In this study, we enhance the low-energy XEA of lanthanide activators by engineering the interfacial defect formation energy (Ef) in CaF2-based heterogeneous core/shell nanoarchitectures. Mechanistic investigations demonstrate that a large lattice misfit between the core and shell reduces the interfacial defect Ef, facilitating the formation of Frenkel defects and significantly increasing XEA intensity after low-energy X-ray irradiation. Specifically, the heterogeneous CaF2:Tb@CaLuF5 core/shell NPs, with a misfit of 3.382 %, exhibit approximately ∼ 8.9 times higher XEA intensity compared to the CaF2:Tb@CaF2 homogeneous core/shell NPs at 10 kV. Furthermore, integrating the CaF2:Tb@CaLuF5 NPs into a flexible scintillation screen enables XEA-based delayed imaging with high spatial resolution, up to approximately 14.2 lp mm−1, and an autofluorescence-free background. These findings advance the development of superior low-energy XEA materials and pave the way for autofluorescence-free three-dimensional X-ray imaging.

Enhancing the Sensitivity and Spatial Imaging Resolution of a Hybrid X-Ray Imaging Screen via Energy Transfer at the ZnS (Ag) and a Thermally Activated Delayed Fluorescence Interface.

Novel scintillation materials have played an indispensable role in the recent remarkable progress witnessed for X-ray imaging technology. Herein, a high-performance X-ray scintillation screen was developed based on a highly efficient hybrid system combining inorganic ZnS (Ag) with thermally activated delayed fluorescence (TADF) scintillator materials via an interfacial energy transfer (EnT) mechanism. ZnS (Ag) has a high X-ray absorption capacity and functions as the initial layer for efficiently converting high-energy X-ray photons into low-energy visible light (acting as a sensitizer) while also serving as an energy donor. The TADF component, on the contrary, is an energy acceptor and forms an active scintillating layer. By harnessing TADF chromophores that can efficiently capture both singlet and triplet excitons, our composite material offers a remarkable spatial imaging resolution of 24 line pairs per millimeter, surpassing those of the majority of existing organic and inorganic scintillators. Further, our interfacial energy transfer strategy effectively amplifies the radioluminescence intensity of the TADF scintillator by a factor of 75, offering an outstanding light yield of 38,000 photons/MeV. This advancement represents a remarkable breakthrough in organic X-ray scintillation technology and is a notable achievement within the X-ray imaging field, paving the way for novel applications in medical imaging and security inspection.

A hot exciton organic glassy scintillator for high-resolution X-ray imaging.

Hot exciton organic scintillators offer promising prospects due to their efficient generation of bright triplet excitons and ultrafast response time, having potential applications in security detection and medical diagnostics. However, fabricating large-area, highly transparent scintillator screens still remains challenging, impeding the realization of high-resolution X-ray imaging. Herein, we firstly demonstrate a novel highly-transparent hot exciton organic glassy scintillator (>87% transmittance @ 450-800 nm), produced using a low-temperature melt-quenching method with 2',5'-difluoro-N4,N4,N4'',N4''-tetraphenyl-[1,1':4',1''-terphenyl]-4,4''-diamine (DTPA2F) powder. Remarkably, compared to crystalline DTPA2F, which has a photoluminescence quantum yield of 67.8% and a relative light yield of 46 400 ± 406 photons MeV-1, the DTPA2F glass retains 49.8% and 28 341 ± 246 photons MeV-1, respectively. This results in a low detection limit of about 53.7 nGy s-1 and an ultrafast decay time of 1.66 ns for DTPA2F glass. Besides, it exhibits excellent environmental stability with no recrystallization or degradation after over 100 days of exposure to ambient conditions. Furthermore, the scintillator screen demonstrates exceptional spatial resolution of 38.5 lp mm-1 for X-ray imaging. It provides a simple molecular design strategy and a screen fabrication method for developing large-area, highly-transparent, efficient and ultrafast organic glassy scintillators.

Achieving Efficient X-ray Scintillation of Purely Organic Phosphorescent Materials by Chromophore Confinement.

Scintillators have attracted significant attention due to their wide-ranging applications in both industrial and medical fields. However, one of the ongoing challenges is the efficient utilization of triplet excitons to achieve high radioluminescence efficiency. Here, a series of purely organic phosphors is presented for X-ray scintillation, employing a combined rigid and flexible host-guest doping strategy. The doped crystals exhibit a remarkable maximum phosphorescence efficiency of 99.4% under UV excitation. Furthermore, upon X-ray irradiation, the radioluminescence intensities of the doped phosphors are markedly higher compared to their single-component crystal counterparts. Through systematic investigations, it is demonstrated the crucial role of confining isolated chromophores in enhancing scintillation efficiency. Additionally, a transparent scintillator screen fabricated with the doped phosphor exhibits excellent X-ray imaging performance, achieving a high spatial resolution of 18.0 lpmm-1. This work not only offers valuable insights into suppressing non-radiative transitions of triplet excitons during scintillation but also opens a new avenue for designing highly efficient purely organic phosphorescent scintillators.

Single activator doped fluoride nanoparticles for X-ray excited high-resolution and delayed flexible nonplanar imaging

Lanthanide doped fluoride nanoparticles (NPs) exhibit adjustable X-ray excited optical/persistent luminescence (XEOL/XEPL) and possessing extensive potential in XEPL-based delay imaging. However, the high-resolution and delayed XEPL-based delay imaging always requires strict introduction of sensitized or heterovalent ions and the construction of complex structures for excellent XEPL performance of lanthanide-doped fluoride NPs, which is attributed to a lack of effective and convenient strategies. Here we show that the intense XEPL strength was obtained by single Tb3+ activated ion doping and simple CsY2F7@NaYF4 core/shell structure for X-ray excited high-resolution and delayed flexible nonplanar imaging. The strict introduction and control of sensitized or heterovalent ions, and the construction of intricate multilayer nanostructure are avoided. In addition, we enable the NPs to achieve high and long-term XEPL performance by simply thermal processing strategy. We successfully mixed minimized amount of the NPs into flexible film to create a scintillation screen which consequently exhibit high surface smoothness, environmental stability, and transparency. Our results demonstrate high resolution delayed imaging of the NPs integrated flexible film for the interior of nonplanar objects. The spatial resolution of 14.3 lp mm−1 is substantially higher than the typical spatial resolutions required for medical CT scans (2 lp mm−1) and X-ray imaging (3.5 lp mm−1). These findings will promote the development of advanced delayed X-ray nonplanar imaging applications.

Development of a water-cooled scintillation screen for high-current beam profiling

This study aimed to develop a scintillation screen monitor for high-current ion beam profiling. It was observed that the conventional scintillation screen is unable to meet the requirements of medium- and high-power accelerators due to the beam damaging the screen and preventing it from functioning properly. Consequently, a water-cooled tantalum-copper composite plate was adopted as the target head and coated with potassium bromide powder. The scintillating screen monitor employs the direct intercept method to observe the beam profile and position recorded by a CCD camera. A water-cooled beam profile monitoring system was manufactured and subjected to preliminary experimental tests on an electron accelerator. The results indicate that the screen monitor exhibits good luminescence, and high resolution, and is capable of effectively evaluating the beam position and profile.

Brightening dark excitons in inorganic halide perovskites by local symmetry breaking

Thermally activated delayed fluorescence (TADF) phenomenon, defined as thermal activation of triplet dark-state excitons into singlet state excitons through reverse intersystem crossing (RISC), has become a prevalent principle for designing organic-based electro-/photo-luminescent molecules. However, activating dark excitons in inorganic metal halide perovskites (MHPs) still remains challenging. Herein, we report an efficient strategy of doping-induced local symmetry breaking to brighten dark excitons in inorganic halide perovskite Cs2ZrCl6, which result in a 500 % enhancement of low-temperature luminescence emission. Lattice symmetry breaking confirmed by the X-ray absorption spectroscopy measurements could disturb the local coordination environment at the Zr site. The singlet-triplet energy gap (ΔEST) fitted from temperature-dependent photoluminescence decay curves decreases from 0.087 to 0.071 eV, thus reducing up-conversion barrier of dark excitons. Theoretical calculation indicates large spatial separation of charge density favorable for enhanced TADF emission. Furthermore, a flexible X-ray scintillator screen with poly (dimethylsiloxane) as the matrix could obtain high-quality X-ray imaging with a 14 lp mm−1 resolution. This work gives insights into improving photoemission of inorganic MHPs via brightening dark excitons.

Active dosimetry for VHEE FLASH radiotherapy using beam profile monitors and charge measurements

The discovery of the FLASH effect has revealed a high potential for treating cancer more efficiently by sparing healthy tissue. The surge in related medical research activities over the last couple of years has triggered a demand for technology with the capability of generating and measuring ionizing radiation at ultra-high dose-rates (UHDR). A reliable dosimetry system is an integral part of a radiotherapy machine. Because existing active dosimetry methods are unable to handle the dose-rates required for FLASH, UHDR dosimetry has emerged as an important area of research. In this paper we present an active dosimetry method based on a scintillating screen and an integrating current transformer. This method provides a simultaneous measurement of the absolute dose delivery as well as the 2D dose distribution. The measurements have been correlated with corresponding readings from radiochromic films (RCFs), and a procedure for image processing has been established. Moreover, different methods of calibrating the active dosimetry system against RCFs have been introduced and evaluated. Lastly, we present results which demonstrate that an agreement with RCFs of better than 5% can be realistically expected if camera parameters are carefully optimized.

Vacuum-filtration fabrication of copper-based halide scintillation screen for high-resolution X-ray imaging

Zero-dimensional (0D) organic-inorganic Cu(I)-based halides have garnered significant attention due to their low toxicity, efficient emission, and moderate fabrication conditions. However, the challenge remains in developing stable and efficient 0D hybrid Cu(I)-based halides for effective X-ray imaging. In this study, a yellow-emitting 0D hybrid copper halide, (ETPP)2Cu2I4 (Ethyl triphenylphosphonium, ETPP), was successfully synthesized via a slow evaporation method. This compound demonstrated an impressive steady-state light yield of 23,200 photons/MeV under X-ray radiation and an ultralow detection limit of 150.9 nGyair s−1, approximately 35 times lower than the standard medical examination dosage. Utilizing a vacuum-filtration method, we fabricated a flexible film that outperforms traditional methods and achieved an exceptional X-ray imaging resolution of 16.0 lp/mm. This study introduces a novel approach to fabricating high-performance X-ray imaging scintillators based on 0D Cu-based halides, showcasing excellent scintillation performance and stability for non-destructive testing.

Large-grain scintillator screens for proton radiography.

Protons from the Los Alamos Neutron Science Center have been used for pulsed radiography in dynamic experiments for the past 25 years. Pulses of protons are imaged on a scintillator, and the light from these images is captured by fast gated cameras. The need for fast, bright scintillators has led to some compromises in image quality due to tiling the scintillators and backgrounds with totally internally reflected light. We show how large-grain scintillator screens, made using a thin plastic binder, solve these problems.

MOSkin dosimetry for an ultra-high dose-rate, very high-energy electron irradiation environment at PEER

FLASH radiotherapy, which refers to the delivery of radiation at ultra-high dose-rates (UHDRs), has been demonstrated with various forms of radiation and is the subject of intense research and development recently, including the use of very high-energy electrons (VHEEs) to treat deep-seated tumors. Delivering FLASH radiotherapy in a clinical setting is expected to place high demands on real-time quality assurance and dosimetry systems. Furthermore, very high-energy electron research currently requires the transformation of existing non-medical accelerators into radiotherapy research environments. Accurate dosimetry is crucial for any such transformation. In this article, we assess the response of the MOSkin, developed by the Center for Medical Radiation Physics, which is designed for on-patient, real-time skin dose measurements during radiotherapy, and whether it exhibits dose-rate independence when exposed to 100 MeV electron beams at the Pulsed Energetic Electrons for Research (PEER) end-station. PEER utilizes the electron beam from a 100 MeV linear accelerator when it is not used as the injector for the ANSTO Australian Synchrotron. With the estimated pulse dose-rates ranging from (7.84±0.21)×105 Gy/s to (1.28±0.03)×107 Gy/s and an estimated peak bunch dose-rate of (2.55±0.06)×108 Gy/s, MOSkin measurements were verified against a scintillating screen to confirm that the MOSkin responds proportionally to the charge delivered and, therefore, exhibits dose-rate independence in this irradiation environment.

Zero-Dimensional Copper(I) Halide Microcrystals as Highly Efficient Scintillators for Flexible X-ray Imaging.

Commercially available rare-earth-doped inorganic oxide materials have been widely applied as X-ray scintillators, but the fragile characteristics, high detection limit, and harsh preparation condition seriously restrict their wide applications. Furthermore, it remains a huge challenge to realize X-ray flexible imaging technology for real-time monitoring of the curving interface of complex devices. To address these issues, we herein report two isostructural cuprous halides of zero-dimensional (0D) [AEPipz]CuX3·X·H2O (AEPipz = N-aminoethylpiperazine, X = Br and I) with controllable size to nanosize crystal as highly efficient scintillators toward flexible X-ray imaging. These cuprous halides exhibit highly efficient cyan photoluminescence and radioluminescence emissions with the highest quantum yield of 92.1% and light yield of 62,400 photons MeV-1, respectively, surpassing most of the commercially available inorganic scintillators. Meanwhile, the ultralow detection limit of 95.7 nGyair s-1 was far below the X-ray dose required for diagnosis (5.5 μGyair s-1). More significantly, the flexible film is facilely assembled with excellent foldability and high crack resistance, which further acts as a scintillation screen achieving a high spatial resolution of 17.4 lp mm-1 in X-ray imaging, demonstrating the potential application in wearable radiation radiography. The combined advantages of high light yield, low detection limit, and excellent flexibility promote these 0D cuprous halides as the most promising X-ray scintillators.

Sub‐10 nm Lanthanide‐Doped Lu6O5F8 Nanoscintillators for Real‐Time High‐Resolution Dynamic 3D X‐Ray Imaging

AbstractLanthanide‐doped fluoride nanoscintillators (NSs) have emerged as promising candidates for X‐ray imaging. However, strong afterglow, long lifetime, and poor irradiation stability pose key challenges for real‐time dynamic X‐ray imaging. In this study, the sub‐10 nm Lu6O5F8:Tb NSs with tunable morphologies are prepared via incorporating Li+/Na+ ions. The X‐ray excited optical luminescence (XEOL) intensity of the Lu6O5F8:15Tb/10Li NSs is stronger than that of NaLuF4:15 Tb NSs with a similar particle size while its afterglow is only ≈2.7% compared to that of NaLuF4:15 Tb NSs. Utilizing the Lu6O5F8:15 Tb/10Li NSs‐integrated film as a scintillator screen, a high resolution of ≈21.6 lp/mm is achieved. Even at a low dose of 0.23 µGy, the fringe detail in the electron device is clearly observed in the X‐ray image. The afterglow intensity of the Lu6O5F8:10Eu/10Li NSs decays to 0.7% at 40 µs, which is better than that of CsI:Tl (3.6%@40 µs). Moreover, the Lu6O5F8:10Eu/10Li NSs with a lifetime of 1.65 µs are verified for use in dynamic 3D X‐ray imaging. These findings represent a significant advancement in the development of new NSs for high‐performance dynamic X‐ray imaging.

Organic Cation Modulation in Manganese Halides to Optimize Crystallization Process and X-Ray Response Toward Large-Area Scintillator Screen.

Manganese halides are one of the most potential candidates for large-area flat-panel detection owing to their biological safety and all-solution preparation. However, reducing photon scattering and enhancing the efficient luminescence of scintillator screens remains a challenge due to their uncontrollable crystallization and serious nonradiative recombination. Herein, an organic cation modulation is reported to control the crystallization process and enhance the luminescence properties of manganese halides. Given the industrial requirements of the X-ray flat-panel detector, the large-area A2MnBr4 screen (900 cm2) with excellent uniformity is blade-coated at 60°C. Theoretical calculations and in situ measurements reveal that organic cations with larger steric hindrance can slow down the crystallization of the screen, thus neatening the crystal arrangement and reducing the photon scattering. Moreover, larger steric hindrance can also endow the material with higher exciton binding energy, which is beneficial for restraining nonradiative recombination. Therefore, the BPP2MnBr4 (BPP = C25H22P+) screen with larger steric hindrance exhibits a superior spatial resolution (>20 lpmm-1) and ultra-low detection limit (< 250 nGyairs-1). This is the first time steric hindrance modulation is used in blade-coated scintillator screens, and it believes this study will provide some guidance for the development of high-performance manganese halide scintillators.

Absolute energy-dependent scintillating screen calibration for real-time detection of laser-accelerated proton bunches.

Laser-plasma accelerators (LPAs) can deliver pico- to nanosecond long proton bunches with ≳100 nC of charge dispersed over a broad energy spectrum. Increasing the repetition rates of today's LPAs is a necessity for their practical application. This, however, creates a need for real-time proton bunch diagnostics. Scintillating screens are one detector solution commonly applied in the field of electron LPAs for spatially resolved particle and radiation detection. Yet their establishment for LPA proton detection is only slowly taking off, also due to the lack of available calibrations. In this paper, we present an absolute proton number calibration for the scintillating screen type DRZ High (Mitsubishi Chemical Corporation, Düsseldorf, Germany), one of the most sensitive screens according to calibrations for relativistic electrons and x rays. The presented absolute light yield calibration shows an uncertainty of the proton number of 10% and can seamlessly be applied at other LPA facilities. For proton irradiation of the DRZ High screen, we find an increase in light yield of >60% compared to reference calibration data for relativistic electrons. Moreover, we investigate the scintillating screen light yield dependence on proton energy since many types of scintillators (e.g., plastic, liquid, and inorganic) show a reduced light yield for increased local energy deposition densities, an effect termed ionization quenching. The ionization quenching can reduce the light yield for low-energy protons by up to ∼20%. This work provides all necessary data for absolute spectral measurements of LPA protons with DRZ High scintillating screens, e.g., when used in the commonly applied Thomson parabola spectrometers.

Controlled Synthesis of Terbium-Doped Colloidal Gd2O2S Nanoplatelets Enables High-Performance X-ray Scintillators.

Terbium-doped gadolinium oxysulfide (Gd2O2S:Tb3+), commonly referred to as Gadox, is a widely used scintillator material due to its exceptional X-ray attenuation efficiency and high light yield. However, Gadox-based scintillators suffer from low X-ray spatial resolution due to their large particle size, which causes significant light scattering. To address this limitation, we report the synthesis of terbium-doped colloidal Gadox nanoplatelets (NPLs) with near-unity photoluminescence quantum yield (PLQY) and high radioluminescence light yield (LY). In particular, our investigation reveals a strong correlation between PLQY, LY, particle size, and Tb3+concentration. Our synthetic approach allows precise control over the lateral size and thickness of the Gadox NPLs, resulting in a LY of 50,000 photons/MeV. Flexible scintillating screens fabricated with the solution-processable Gadox NPLs exhibited a 20 lp/mm X-ray spatial resolution, surpassing commercial Gadox scintillators. These high-performance and flexible Gadox NPL-based scintillators enable enhanced X-ray imaging capabilities in medicine and security. Our work provides a framework for designing nanomaterial scintillators with superior spatial resolution and efficiency through precise control of dimensions and dopant concentration.

Clinical boundary conditions for propagation-based X-ray phase contrast imaging: from bio-sample models targeting to clinical applications.

Typical propagation-based X-ray phase contrast imaging (PB-PCI) experiments using polyenergetic sources are tested in very ideal conditions: low-energy spectrum (mainly characteristic X-rays), small thickness and homogeneous materials considered weakly absorbing objects, large object-to-detector distance, long exposure times and non-clinical detector. Explore PB-PCI features using boundary conditions imposed by a low power polychromatic X-ray source (X-ray spectrum without characteristic X-rays), thick and heterogenous materials and a small area imaging detector with high low-detection radiation threshold, elements commonly found in a clinical scenario. A PB-PCI setup implemented using a microfocus X-ray source and a dental imaging detector was characterized in terms of different spectra and geometric parameters on the acquired images. Test phantoms containing fibers and homogeneous materials with close attenuation characteristics and animal bone and mixed soft tissues (bio-sample models) were analyzed. Contrast to Noise Ratio (CNR), system spatial resolution and Kerma values were obtained for all images. Phase contrast images showed CNR up to 15% higher than conventional contact images. Moreover, it is better seen when large magnifications (>3) and object-to-detector distances (>13 cm) were used. The influence of the spectrum was not appreciable due to the low efficiency of the detector (thin scintillator screen) at high energies. Despite the clinical boundary condition used in this work, regarding the X-ray spectrum, thick samples, and detection system, it was possible to acquire phase contrast images of biological samples.