Molecular Imaging of Pulmonary Fibrosis.

Fibrosing lung diseases affect over 160,000 individuals in the United States alone and can carry a prognosis that is worse than many cancers. Antifibrotic treatments modify only the rate of fibrosis progression, and more effective therapies are urgently needed. Molecular imaging enables visualization of disease pathogenesis in progress.

Chinese herbal medicine for dyspnea and persistent symptoms of long COVID: A systematic review and meta-analysis of randomized controlled trials.

Background: Over 65 million people have long COVID. Evidence for using Chinese herbal medicine (CHM) to treat long COVID is growing. A systematic review of evidence for guiding clinical decision is warranted.

Domain-conditioned and Temporal-guided Diffusion Modeling for Accelerated Dynamic MRI Reconstruction.

Purpose: To propose a domain-conditioned and temporal-guided diffusion modeling method, termed dynamic Diffusion Modeling (dDiMo), for accelerated dynamic MRI reconstruction, enabling diffusion process to characterize spatiotemporal information for time-resolved multi-coil Cartesian and non-Cartesian data.

Methods: The dDiMo framework integrates temporal information from time-resolved dimensions, allowing for the concurrent capture of intra-frame spatial features and inter-frame temporal dynamics in diffusion modeling. It employs additional spatiotemporal ($x$-$t$) and self-consistent frequency-temporal ($k$-$t$) priors to guide the diffusion process.

Manganese-based type I collagen-targeting MRI probe for in vivo imaging of liver fibrosis.

Liver fibrosis is a common pathway shared by all forms of progressive chronic liver disease. There is an unmet clinical need for noninvasive imaging tools to diagnose and stage fibrosis, which presently relies heavily on percutaneous liver biopsy. Here we explored the feasibility of using a novel type I collagen-targeted manganese (Mn)-based MRI probe, Mn-CBP20, for liver fibrosis imaging.

Quantitative in Vivo Molecular MRI.

Molecular magnetic resonance imaging (MRI) combines chemistry, chemical biology, and imaging techniques to track molecular events non-invasively. Quantitative molecular MRI aims to provide meaningful, reproducible numerical measurements of molecular processes or biochemical targets within the body. In this review, the classifications of molecular MRI probes based on their signal-generating mechanism and functionality are first described.

Improving standardization and accuracy of in vivo omega plot exchange parameter determination using rotating-frame model-based fitting of quasi-steady-state Z-spectra.

Purpose: Although Ω-plot-driven quantification of in vivo amide exchange properties has been demonstrated, differences in scan parameters may complicate the fidelity of determination. This work systematically evaluated the use of quasi-steady-state (QUASS) Z-spectra reconstruction to standardize in vivo amide exchange quantification across acquisition conditions and further determined it in vivo.

Methods: Simulation and in vivo rodent brain chemical exchange saturation transfer (CEST) data at 4.

Simultaneous Positron Emission Tomography and Molecular Magnetic Resonance Imaging of Cardiopulmonary Fibrosis in a Mouse Model of Left Ventricular Dysfunction.

Background: Aging-associated left ventricular dysfunction promotes cardiopulmonary fibrogenic remodeling, Group 2 pulmonary hypertension (PH), and right ventricular failure. At the time of diagnosis, cardiac function has declined, and cardiopulmonary fibrosis has often developed. Here, we sought to develop a molecular positron emission tomography (PET)-magnetic resonance imaging (MRI) protocol to detect both cardiopulmonary fibrosis and fibrotic disease activity in a left ventricular dysfunction model.

Imaging kidney inflammation using an oxidatively activated MRI probe.

Imaging tools for kidney inflammation could improve care for patients suffering inflammatory kidney diseases by lessening reliance on percutaneous biopsy or biochemical tests alone. During kidney inflammation, infiltration of myeloid immune cells generates a kidney microenvironment that is oxidizing relative to normal kidney. Here, we evaluated whether magnetic resonance imaging (MRI) using the redox-active iron (Fe) complex Fe-PyC3A as an oxidatively activated probe could serve as a marker of kidney inflammation using mouse models of unilateral ischemia-reperfusion injury (IRI) and lupus nephritis (MRL-lpr mice).

Plasma NEDD9 is increased following SARS-CoV-2 infection and associates with indices of pulmonary vascular dysfunction.

Compared to healthy volunteers, participants with post-acute sequelae of SARS-CoV-2 infection (PASC) demonstrated increased plasma levels of the prothrombotic protein NEDD9, which associated inversely with indices of pulmonary vascular function. This suggests persistent pulmonary vascular dysfunction may play a role in the pathobiology of PASC.

Specific and rapid guanidinium CEST imaging using double saturation power and QUASS analysis in a rodent model of global ischemia.

Purpose: Guanidinium CEST is sensitive to metabolic changes and pH variation in ischemia, and it can offer advantages over conventional pH-sensitive amide proton transfer (APT) imaging by providing hyperintense contrast in stroke lesions. However, quantifying guanidinium CEST is challenging due to multiple overlapping components and a close frequency offset from water. This study aims to evaluate the applicability of a new rapid and model-free CEST quantification method using double saturation power, termed DSP-CEST, for isolating the guanidinium CEST effect from confounding factors in ischemia.

Portable electrical impedance tomography (EIT) system stages non-alcoholic fatty liver disease for potential screening and monitoring at home.

This study demonstrates the feasibility of predicting NAFLD using multi-spectral electrical impedance tomography (EIT), group source separation, constant reference EIT and anthropometric measures. Vibration-controlled Transient Elastography (VCTE) Controlled Attenuated Parameter (CAP; n = 121) and magnetic resonance imaging-proton density fat fraction (MRI-PDFF; n = 34) achieved a sensitivity of 70.9% and specificity of 73.

Global and regional lung function assessment using portable electrical impedance tomography (EIT) system: clinical study.

Recent development of affordable, portable and self-administrable electrical impedance tomography (EIT) system demonstrated the feasibility of using standalone EIT and subject's anthropometrics to predict the gold standard spirometry indicators for lung-function assessment. Compared to spirometry, the system showed the advantage of providing spatial mapping of the spirometry indicators. Nevertheless, the previous study was limited to healthy subjects.

Noninvasive Quantification of Radiation-Induced Lung Injury Using a Targeted Molecular Imaging Probe.

Purpose: Radiation-induced lung injury (RILI) is a progressive inflammatory process seen after irradiation for lung cancer. The disease can be insidious, often characterized by acute pneumonitis followed by chronic fibrosis with significant associated morbidity. No therapies are approved for RILI, and accurate disease quantification is a major barrier to improved management.

Detection of Pulmonary Fibrosis with a Collagen-Mimetic Peptide.

Idiopathic pulmonary fibrosis (IPF) is a disease of unknown etiology that is characterized by excessive deposition and abnormal remodeling of collagen. IPF has a mean survival time of only 2-5 years from diagnosis, creating a need to detect IPF at an earlier stage when treatments might be more effective. We sought to develop a minimally invasive probe that could detect molecular changes in IPF-associated collagen.

Noninvasive Quantification of Radiation-Induced Lung Injury using a Targeted Molecular Imaging Probe.

Rationale: Radiation-induced lung injury (RILI) is a progressive inflammatory process commonly seen following irradiation for lung cancer. The disease can be insidious, often characterized by acute pneumonitis followed by chronic fibrosis with significant associated morbidity. No therapies are approved for RILI, and accurate disease quantification is a major barrier to improved management.

Optimization of an Allysine-Targeted PET Probe for Quantifying Fibrogenesis in a Mouse Model of Pulmonary Fibrosis.

Purpose: Idiopathic pulmonary fibrosis (IPF) is a destructive lung disease with a poor prognosis, an unpredictable clinical course, and inadequate therapies. There are currently no measures of disease activity to guide clinicians making treatment decisions. The aim of this study was to develop a PET probe to identify lung fibrogenesis using a pre-clinical model of pulmonary fibrosis, with potential for translation into clinical use to predict disease progression and inform treatment decisions.

Tailored Chemical Reactivity Probes for Systemic Imaging of Aldehydes in Fibroproliferative Diseases.

During fibroproliferation, protein-associated extracellular aldehydes are formed by the oxidation of lysine residues on extracellular matrix proteins to form the aldehyde allysine. Here we report three Mn(II)-based, small-molecule magnetic resonance probes that contain α-effect nucleophiles to target allysine in vivo and report on tissue fibrogenesis. We used a rational design approach to develop turn-on probes with a 4-fold increase in relaxivity upon targeting.

Tailored chemical reactivity probes for systemic imaging of aldehydes in fibroproliferative diseases.

During fibroproliferation, protein-associated extracellular aldehydes are formed by the oxidation of lysine residues on extracellular matrix proteins to form the aldehyde allysine. Here we report three Mn(II)-based, small molecule magnetic resonance (MR) probes that contain α-effect nucleophiles to target allysine in vivo and report on tissue fibrogenesis. We used a rational design approach to develop turn-on probes with a 4-fold increase in relaxivity upon targeting.

Biodistribution, Dosimetry, and Pharmacokinetics of Ga-CBP8: A Type I Collagen-Targeted PET Probe.

The Ga-Collagen Binding Probe #8, Ga-CBP8, is a peptide-based, type I collagen-targeted probe developed for imaging of tissue fibrosis. The aim of this study was to determine the biodistribution, dosimetry, and pharmacokinetics of Ga-CBP8 in healthy human subjects. Nine healthy volunteers (5 male and 4 female) underwent whole-body Ga-CBP8 PET/MRI using a Biograph mMR scanner.