First-in-class MKK4 inhibitors enhance liver regeneration and prevent liver failure.

Diminished hepatocyte regeneration is a key feature of acute and chronic liver diseases and after extended liver resections, resulting in the inability to maintain or restore a sufficient functional liver mass. Therapies to restore hepatocyte regeneration are lacking, making liver transplantation the only curative option for end-stage liver disease. Here, we report on the structure-based development and characterization (nuclear magnetic resonance [NMR] spectroscopy) of first-in-class small molecule inhibitors of the dual-specificity kinase MKK4 (MKK4i).

Diagnostic Performance in Low- and High-Contrast Tasks of an Image-Based Denoising Algorithm Applied to Radiation Dose-Reduced Multiphase Abdominal CT Examinations.

Anatomic redundancy between phases can be used to achieve denoising of multiphase CT examinations. A limitation of iterative reconstruction (IR) techniques is that they generally require use of CT projection data. A frequency-split multi-band-filtration algorithm applies denoising to the multiphase CT images themselves.

Technical note: Evaluation of artificial 120-kilovolt computed tomography images for radiation therapy applications.

Purpose: The purpose of this work is to evaluate the scaled computed tomography (CT) number accuracy of an artificial 120 kV reconstruction technique based on phantom experiments in the context of radiation therapy planning.

Methods: An abdomen-shaped electron density phantom was scanned on a clinical CT scanner capable of artificial 120 kV reconstruction using different tube potentials from 70 to 150 kV. A series of tissue-equivalent phantom inserts (lung, adipose, breast, solid water, liver, inner bone, 30%/50% CaCO , cortical bone) were placed inside the phantom.

Characterization of thrombus composition with multimodality CT-based imaging: an in-vitro study.

Background: CT is the most commonly used imaging modality for acute ischemic stroke evaluation. There is growing interest to use pre-operative imaging to characterize clot composition in stroke. We performed an in-vitro study examining the ability of various CT techniques in differentiation between different clot types.

Preconditioning with Foam-mediated External Suction on Flap Microvasculature and Perfusion in a Rodent Model.

Unlabelled: Foam-mediated external suction (FMES) has previously shown to improve tissue microcirculation. We hypothesized that preconditioning fasciocutaneous perforator flaps with FMES would augment perfusion and demonstrate greater capillary recruitment.

Methods: Gluteal perforator flaps were designed on sixteen 400 g rats.

Multi-energy CT imaging for large patients using dual-source photon-counting detector CT.

Multi-energy CT imaging of large patients with conventional dual-energy (DE)-CT using an energy-integrating-detector (EID) is challenging due to photon starvation-induced image artifacts, especially in lower tube potential (80-100 kV) images. Here, we performed phantom experiments to investigate the performance of DECT for morbidly obese patients, using an iodine and water material decomposition task as an example, on an emulated dual-source (DS)-photon-counting-detector (PCD)-CT, and compared its performance with a clinical DS-EID-CT. An abdominal CT phantom with iodine inserts of different concentrations was wrapped with tissue-equivalent gel layers to emulate a large patient (50 cm lateral size).

CT-based internal density calibration for opportunistic skeletal assessment using abdominal CT scans.

CT-based opportunistic skeletal assessment complements current osteoporosis diagnosis. Quantitative assessment by internal density calibration overcomes the limitations of phantom-based calibration. We sought to establish and validate an internal calibration technique using abdominal CT scans and establish reproducibility precision for three density calibration techniques.

A Universal Protocol for Abdominal CT Examinations Performed on a Photon-Counting Detector CT System: A Feasibility Study.

Objective: The aims of this study were to investigate the feasibility of using a universal abdominal acquisition protocol on a photon-counting detector computed tomography (PCD-CT) system and to compare its performance to that of single-energy (SE) and dual-energy (DE) CT using energy-integrating detectors (EIDs).

Methods: Iodine inserts of various concentrations and sizes were embedded into different sizes of adult abdominal phantoms. Phantoms were scanned on a research PCD-CT and a clinical EID-CT with SE and DE modes.

Spatial Accuracy of a Clinically Established Noninvasive Electrocardiographic Imaging System for the Detection of Focal Activation in an Intact Porcine Model.

Background: Noninvasive electrocardiographic imaging (ECGi) is used clinically to map arrhythmias before ablation. Despite its clinical use, validation data regarding the accuracy of the system for the identification of arrhythmia foci is limited.

Methods: Nine pigs underwent closed-chest placement of endocardial fiducial markers, computed tomography, and pacing in all cardiac chambers with ECGi acquisition.

Author Correction: Sustained perfusion of revascularized bioengineered livers heterotopically transplanted into immunosuppressed pigs.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Evaluation of Lower-Dose Spiral Head CT for Detection of Intracranial Findings Causing Neurologic Deficits.

Background And Purpose: Despite the frequent use of unenhanced head CT for the detection of acute neurologic deficit, the radiation dose for this exam varies widely. Our aim was to evaluate the performance of lower-dose head CT for detection of intracranial findings resulting in acute neurologic deficit.

Materials And Methods: Projection data from 83 patients undergoing unenhanced spiral head CT for suspected neurologic deficits were collected.

Determination of iodine detectability in different types of multiple-energy images for a photon-counting detector computed tomography system.

In addition to low-energy-threshold images (TLIs), photon-counting detector (PCD) computed tomography (CT) can generate virtual monoenergetic images (VMIs) and iodine maps. Our study sought to determine the image type that maximizes iodine detectability. Adult abdominal phantoms with iodine inserts of various concentrations and lesion sizes were scanned on a PCD-CT system.

Sustained perfusion of revascularized bioengineered livers heterotopically transplanted into immunosuppressed pigs.

Implanted bioengineered livers have not exceeded three days of continuous perfusion. Here we show that decellularized whole porcine livers revascularized with human umbilical vein endothelial cells and implanted heterotopically into immunosuppressed pigs whose spleens had been removed can sustain perfusion for up to 15 days. We identified peak glucose consumption rate as a main predictor of the patency of the revascularized bioengineered livers (rBELs).

Polish Helicopter Emergency Medical Service (HEMS) Response to Stroke: A Five-Year Retrospective Study.

BACKGROUND A stroke is a serious life-threatening emergency that requires immediate intervention in an appropriate therapeutic center. The aim of this study was to analyze the time of medical procedures at the scene and changes in the state of stroke patients during transport by HEMS in Poland. The presented research is the first nationwide study covering such a large group of stroke patients, for whom aerial support was used in the therapeutic process.

Clinical utility of virtual noncalcium dual-energy CT in imaging of the pelvis and hip.

Dual-energy virtual noncalcium images are increasingly used to identify marrow edema which accompanies bony pelvic injuries and marrow pathology obscured by cancellous bone. We present a clinical perspective of our experience using virtual noncalcium images in the work up of pelvic osseous pathology.

Dual-Energy CT Monitoring of Cryoablation Zone Growth in the Spinal Column and Bony Pelvis: A Laboratory Study.

Purpose: To evaluate the use of dual-energy computed tomography (CT) virtual noncalcium imaging (VNCa) to visualize ice ball growth during skeletal cryoablation procedures in the spine and bony pelvis.

Materials And Methods: Cryoablation was performed in the spine and bony pelvis of swine and human cadavers at 5 and 6 locations, respectively. CT scans were acquired every 2 minutes using a dual-source dual-energy scanner.

Dual-source photon counting detector CT with a tin filter: a phantom study on iodine quantification performance.

Photon counting detectors (PCD) can provide spectral information to enable iodine quantification through multi-energy imaging but performance is limited by current PCD technology. The purpose of this work is to evaluate iodine quantification in a phantom study using dual-source PCD-CT (DS-PCD-CT), and compare to single-source (SS)-PCD-CT and traditional DS energy integrating detector (EID)-based dual-energy CT. A multi-energy CT phantom with iodine inserts (0 to 15 mg ml concentration) was imaged on a research SS-PCD-CT scanner (CTDI  =  18 mGy).

Reappraisal of Perforasomes of the Superficial Femoral, Descending Genicular, and Saphenous Arteries and Clinical Applications to Locoregional Reconstruction.

Background: The superficial femoral artery and medial thigh region has been an underused donor site for perforator flaps. This study evaluated perforasomes of the superficial femoral artery and its principal branches to review the clinical applications for locoregional reconstruction.

Methods: Twenty-six fresh cadaveric lower extremities were dissected.

Clinical Assessment of Metal Artifact Reduction Methods in Dual-Energy CT Examinations of Instrumented Spines.

Objective: The purpose of this study was to evaluate the performance of three metal artifact reduction methods in dual-energy CT (DECT) examinations of instrumented spines.

Materials And Methods: Twenty patients with instrumented spines who underwent spine DECT were retrospectively identified. All scans were obtained on a dual-source 128-MDCT scanner.

Renal Adiposity Does not Preclude Quantitative Assessment of Renal Function Using Dual-Energy Multidetector CT in Mildly Obese Human Subjects.

Rationale And Objectives: Multidetector computed tomography (MDCT) is useful for measuring in the research setting single-kidney perfusion and function using iodinated contrast time-attenuation curves. Obesity promotes deposition of intrarenal fat, which might decrease tissue attenuation and thereby interfere with quantification of renal function using MDCT. The purpose of this study was to test the hypothesis that background subtraction adequately accounts for intrarenal fat deposition in mildly obese human subjects during renal contrast enhanced dynamic CT.

Soluble tumour necrosis factor receptor I is a promising early indicator of complicated clinical outcome in patients following severe trauma.

Post-traumatic mortality rates are still very high and show an increasing tendency. Early identification of patients at high risk of severe complications has a significant impact on treatment outcomes. The aim of the study was to better understand the early pathological inflammatory response to injury and infection, and to determine the usefulness of the assessment of TNF-α and sTNFR1 concentrations in the peripheral blood as early indicators of severe post-traumatic complications.

Theoretical and experimental analysis of photon counting detector CT for proton stopping power prediction.

Purpose: Photon counting detectors (PCDs) are being introduced in advanced x-ray computed tomography (CT) scanners. From a single PCD-CT acquisition, multiple images can be reconstructed, each based on only a part of the original x-ray spectrum. In this study, we investigated whether PCD-CT can be used to estimate stopping power ratios (SPRs) for proton therapy treatment planning, both by comparing to other SPR methods proposed for single energy CT (SECT) and dual energy CT (DECT) as well as to experimental measurements.

Concurrent Assessment of Cartilage Morphology and Bone Microarchitecture in the Human Knee Using Contrast-Enhanced HR-pQCT Imaging.

Osteoarthritis (OA) is a prevalent articular disease characterized by whole joint degradation, including articular cartilage and bone. Presently, no single imaging modality is well suited to concurrently capture these changes. Recent ex vivo animal studies have demonstrated the efficacy of utilizing contrast agents in conjunction with micro-CT as a means of evaluating cartilage and bone alterations concurrently, though no work as of yet has been performed in large animal models or humans.

Determination of Optimal Image Type and Lowest Detectable Concentration for Iodine Detection on a Photon Counting Detector-Based Multi-Energy CT System.

Photon counting detector (PCD) based multi-energy CT is able to generate different types of images such as virtual monoenergetic images (VMIs) and material specific images (e.g., iodine maps) in addition to the conventional single energy images.

Randomized Trial of Spheroid Reservoir Bioartificial Liver in Porcine Model of Posthepatectomy Liver Failure.

Acute liver failure (ALF) is a catastrophic condition that can occur after major liver resection. The aim of this study was to determine the effects of the spheroid reservoir bio-artificial liver (SRBAL) on survival, serum chemistry, and liver regeneration in posthepatectomy ALF pigs. Wild-type large white swine (20 kg-30 kg) underwent intracranial pressure (ICP) probe placement followed by 85% hepatectomy.