U-SPECT-II: An Ultra-High-Resolution Device for Molecular Small-Animal Imaging

We present a new rodent SPECT system (U-SPECT-II) that enables molecular imaging of murine organs down to resolutions of less than half a millimeter and high-resolution total-body imaging. Methods: The U-SPECT-II is based on a triangular stationary detector set-up, an XYZ stage that moves the animal during scanning, and interchangeable cylindric...

On-Chip Pixel Binning in Photon-Counting EMCCD-Based Gamma Camera: A Powerful Tool for Noise Reduction

Charge Coupled Devices (CCDs) optically coupled to scintillation crystals can be used to construct high resolution gamma cameras. Previously, several groups have reported intrinsic detector spatial resolutions below 100 microns. When the CCD images can be read out fast enough, the energy and interaction position of individual gamma quanta can be...

Absolute quantitative total-body small-animal SPECT with focusing pinholes

Purpose: In pinhole SPECT, attenuation of the photon flux on trajectories between source and pinholes affects quantitative accuracy of reconstructed images. Previously we introduced iterative methods that compensate for image degrading effects of detector and pinhole blurring, pinhole sensitivity and scatter for multi-pinhole SPECT. The aim of...

Targeted multi-pinhole SPECT

Purpose: Small-animal single photon emission computed tomography (SPECT) with focused multi-pinhole collimation geometries allows scanning modes in which large amounts of photons can be collected from specific volumes of interest. Here we present new tools that improve targeted imaging of specific organs and tumours, and validate the effects of...

Effects of attenuation map accuracy on attenuation-corrected micro-SPECT images

Background In single-photon emission computed tomography (SPECT), attenuation of photon flux in tissue affects quantitative accuracy of reconstructed images. Attenuation maps derived from X-ray computed tomography (CT) can be employed for attenuation correction. The attenuation coefficients as well as registration accuracy between SPECT and CT...

U-SPECT-BioFluo: An integrated radionuclide, bioluminescence, and fluorescence imaging platform

Background: In vivo bioluminescence, fluorescence, and single-photon emission computed tomography (SPECT) imaging provide complementary information about biological processes. However, to date these signatures are evaluated separately on individual preclinical systems. In this paper, we introduce a fully integrated bioluminescence-fluorescence...

uPAR-targeted multimodal tracer for pre- and intraoperative imaging in cancer surgery

Pre- and intraoperative diagnostic techniques facilitating tumor staging are of paramount importance in colorectal cancer surgery. The urokinase receptor (uPAR) plays an important role in the development of cancer, tumor invasion, angiogenesis, and metastasis and over-expression is found in the majority of carcinomas. This study aims to develop...

Utilizing high-energy γ-photons for high-resolution ²¹³Bi SPECT in mice

The combined α-, γ-, and x-ray emitter ²¹³Bi (half-life, 46 min) is promising for radionuclide therapy. SPECT imaging of ²¹³Bi is challenging, because most emitted photons have a much higher energy (440 keV) than common in SPECT. We assessed ²¹³Bi imaging capabilities of the Versatile Emission Computed...

SPECT/CT Imaging of Pluronic Nanocarriers with Varying Poly(ethylene oxide) Block Length and Aggregation State

Optimal biodistribution and prolonged circulation of nanocarriers improve diagnostic and therapeutic effects of enhanced permeability and retention-based nanomedicines. Despite extensive use of Pluronics in polymer-based pharmaceuticals, the influence of different poly(ethylene oxide) (PEO) block length and aggregation state on the...

EXIRAD-3D: Fast automated three-dimensional autoradiography

Introduction: Autoradiography is an established technique for high-resolution imaging of radiolabelled molecules in biological tissue slices. Unfortunately, creating a 3D image from a set of these 2D images is extremely time-consuming and error-prone. MicroSPECT systems provide such 3D images but have a low resolution. Here we present EXIRAD...

Characterization of a multi-pinhole molecular breast tomosynthesis scanner

In recent years, breast imaging using radiolabelled molecules has attracted significant interest. Our group has proposed a multi-pinhole molecular breast tomosynthesis (MP-MBT) scanner to obtain 3D functional molecular breast images at high resolutions. After conducting extensive optimisation studies using simulations, we here present a first...

Efficient Monte-Carlo based system modelling for image reconstruction in preclinical pinhole SPECT

The use of multi-pinhole collimation has enabled ultra-high-resolution imaging of SPECT and PET tracers in small animals. Key for obtaining high-quality images is the use of statistical iterative image reconstruction with accurate energy-dependent photon transport modelling through collimator and detector. This can be incorporated in a system...

A scanning focus nuclear microscope with multi-pinhole collimation

Microscopic nuclear imaging down to spatial resolutions of a few hundred microns can already be achieved using low-energy gamma emitters (e.g. ¹²⁵I, ∼30 keV) and a basic single micro-pinhole gamma camera. This has been applied to in vivo mouse thyroid imaging, for example. For clinically used radionuclides such as ^99mTc,...

Evaluating the Targeting of a Staphylococcus-aureus-Infected Implant with a Radiolabeled Antibody In Vivo

Implant infections caused by Staphylococcus aureus are difficult to treat due to biofilm formation, which complicates surgical and antibiotic treatment. We introduce an alternative approach using monoclonal antibodies (mAbs) targeting S. aureus and provide evidence of the specificity and biodistribution of S.-aureus-targeting antibodies in a...