Improved Peritoneal Cavity and Abdominal Organ Imaging Using a Biphasic Contrast Agent Protocol and Spectral Photon Counting Computed Tomography K-Edge Imaging
Objectives To validate in vitro the capability of a high-spatial-resolution prototype spectral photon-counting computed tomography (SPCCT) scanner to differentiate between 2 contrast agents and to assess in vivo the image quality and the feasibility to image the peritoneal cavity in rats using the 2 contrast agents simultaneously within the vascular and peritoneal compartments. Materials and Methods The authors performed SPCCT imaging (100 mAs, 120 kVp) with energy bin thresholds set to 30, 51, 64, 72, and 85 keV in vitro on a custom-made polyoxymethylene cylindrical phantom consisting of tubes with dilutions of both ...
Source: Investigative Radiology - September 7, 2018 Category: Radiology Tags: Original Articles Source Type: research

Targeted Imaging of Renal Fibrosis Using Antibody-Conjugated Gold Nanoparticles in Renal Artery Stenosis
Conclusion Gold nanoparticles conjugated to an anti-collagen-I antibody are able to visualize kidney fibrosis in vitro and in situ and may be useful for nondestructive quantification of tissue fibrosis. (Source: Investigative Radiology)
Source: Investigative Radiology - September 7, 2018 Category: Radiology Tags: Original Articles Source Type: research

Evaluation of Safety Guidelines on the Use of Iodinated Contrast Material: Conundrum Continued
Objectives Recently, safety guidelines for the use of intravascular iodinated contrast material have been updated, and the recommended threshold for giving prophylaxis to prevent contrast-induced nephropathy (CIN) has been reduced to estimated glomerular filtration rate (eGFR) less than 30 mL/min/1.73 m2. Data on this population in the context of CIN, especially evidence for efficacy of the recommendation of prophylactic intravenous hydration, are lacking. The aim of the current study was to test implicit assumptions underlying the guideline update: (1) patients with eGFR (Source: Investigative Radiology)
Source: Investigative Radiology - September 7, 2018 Category: Radiology Tags: Original Articles Source Type: research

Feasibility of Dynamic Contrast-Enhanced Magnetic Resonance Imaging Using Low-Dose Gadolinium: Comparative Performance With Standard Dose in Prostate Cancer Diagnosis
Conclusions These preliminary results suggest that DCE-MRI with a low GBCA dose distinguishes PCa from benign prostate tissue more effectively than does the standard GBCA dose, based on signal enhancement rate. Diagnostic accuracy is similar on qualitative assessment. Prostate cancer diagnosis may be feasible with DCE-MRI with low-dose GBCA. In addition, comparison of enhancement kinetics after low and high doses of contrast media may provide diagnostically useful information. (Source: Investigative Radiology)
Source: Investigative Radiology - September 7, 2018 Category: Radiology Tags: Original Articles Source Type: research

Fast Abdominal Contrast-Enhanced Imaging With High Parallel-Imaging Factors Using a 60-Channel Receiver Coil Setup: Comparison With The Standard Coil Setup
Conclusions The 60-channel coil setup facilitates improved SNR and image quality at high PAT factors with diagnostic image quality, which allows for accelerated contrast-enhanced MR imaging of the abdomen. (Source: Investigative Radiology)
Source: Investigative Radiology - September 7, 2018 Category: Radiology Tags: Original Articles Source Type: research

Continuous Hepatic Arterial Multiphase Magnetic Resonance Imaging During Free-Breathing
Purpose The aim of this study was to evaluate the feasibility of a prototype volume-interpolated breath-hold examination (VIBE) sequence using compressed sensing (VIBECS) for rapid multiphase arterial magnetic resonance imaging (MRI) at different temporal resolution during free-breathing in comparison with a conventional breath-hold approach (VIBESTD). Material and Methods A total of 40 patients with liver malignancies were prospectively included in this study and underwent contrast-enhanced liver MRI at 1.5 T to evaluate the performance of VIBECS for rapid arterial multiphase imaging. An additional 40 patients examin...
Source: Investigative Radiology - September 7, 2018 Category: Radiology Tags: Original Articles Source Type: research

Diffusion-Weighted Imaging With Apparent Diffusion Coefficient Mapping for Breast Cancer Detection as a Stand-Alone Parameter: Comparison With Dynamic Contrast-Enhanced and Multiparametric Magnetic Resonance Imaging
Purpose The aims of this study were to compare dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) with apparent diffusion coefficient mapping as a stand-alone parameter without any other supportive sequence for breast cancer detection and to assess its combination as multiparametric MRI (mpMRI) of the breast. Materials and Methods In this institutional review board–approved single-center study, prospectively acquired data of 106 patients who underwent breast MRI from 12/2010 to 09/2014 for an imaging abnormality (Breast Imaging Reporting and Data System 0, 4/5)...
Source: Investigative Radiology - September 7, 2018 Category: Radiology Tags: Original Articles Source Type: research

Multireader Study on the Diagnostic Accuracy of Ultrafast Breast Magnetic Resonance Imaging for Breast Cancer Screening
Objectives Breast cancer screening using magnetic resonance imaging (MRI) has limited accessibility due to high costs of breast MRI. Ultrafast dynamic contrast-enhanced breast MRI can be acquired within 2 minutes. We aimed to assess whether screening performance of breast radiologist using an ultrafast breast MRI-only screening protocol is as good as performance using a full multiparametric diagnostic MRI protocol (FDP). Materials and Methods The institutional review board approved this study, and waived the need for informed consent. Between January 2012 and June 2014, 1791 consecutive breast cancer screening examina...
Source: Investigative Radiology - September 7, 2018 Category: Radiology Tags: Original Articles Source Type: research

Dechelation (Transmetalation): Consequences and Safety Concerns With the Linear Gadolinium-Based Contrast Agents, In View of Recent Health Care Rulings by the EMA (Europe), FDA (United States), and PMDA (Japan)
The issue of dechelation (transmetallation) in vivo after administration of the linear gadolinium-based contrast agents, and potential safety concerns, is considered on the basis of an extensive, focused literature review. Early indications of potential problems included the high level of excess ligand used in the formulation of 2 agents (indeed the 2 least stable thermodynamically) and interference with laboratory tests when blood was drawn from patients relatively soon after administration of these same agents. The advent of nephrogenic systemic fibrosis in the late 2000s raised additional major concerns. The correlatio...
Source: Investigative Radiology - September 7, 2018 Category: Radiology Tags: Review Article Source Type: research

Modeling Gadoxetate Liver Uptake and Efflux Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging Enables Preclinical Quantification of Transporter Drug-Drug Interactions
Conclusions This study presents the first in vivo implementation of a 2-compartment uptake and efflux model to monitor DDIs at the transporter-protein level, using the clinically relevant organic anion transporting polypeptide inhibitor rifampicin. The technique has the potential to be a novel alternative to other methods, allowing real-time changes in transporter DDIs to be measured directly in vivo. (Source: Investigative Radiology)
Source: Investigative Radiology - August 8, 2018 Category: Radiology Tags: Original Articles Source Type: research

Influence of Gadolinium-Based Contrast Agents on Tissue Sodium Quantification in Sodium Magnetic Resonance Imaging
Conclusions Our study showed a quantitative influence of Dotarem and Gadovist on sodium relaxation times. However, quantification of TSC was not impaired, which was proven by worst case calculations and nonsignificant differences in vivo in an ischemic stroke patient. We suggest performing sodium imaging in useful clinical positions in protocols regardless of included Dotarem or Gadovist administrations. Being flexible in the study protocol design will strengthen ongoing sodium imaging investigations for various pathologies. (Source: Investigative Radiology)
Source: Investigative Radiology - August 8, 2018 Category: Radiology Tags: Original Articles Source Type: research

Breakthrough Reactions to Gadobenate Dimeglumine
Conclusion Premedication does not eliminate severe reactions to gadobenate dimeglumine. Breakthrough reactions to gadobenate dimeglumine can be of greater severity than index reactions. (Source: Investigative Radiology)
Source: Investigative Radiology - August 8, 2018 Category: Radiology Tags: Original Articles Source Type: research

10 Years of Nephrogenic Systemic Fibrosis: A Comprehensive Analysis of Nephrogenic Systemic Fibrosis Reports Received by a Pharmaceutical Company from 2006 to 2016
Conclusions Year of market introduction, as well as US market share in 2000 to 2007, greatly influenced the absolute number of NSF reports for each GBCA, their a priori probability to cause NSF, as well as their a priori probability to be associated with unconfounded cases of NSF. Variability in case interpretation and pharmacovigilance approaches also influence the absolute number of unconfounded cases and should therefore not be used for comparative risk assessments. This should be primarily based on objective product parameters such as structure, stability, pharmacokinetics, and dose. (Source: Investigative Radiology)
Source: Investigative Radiology - August 8, 2018 Category: Radiology Tags: Original Articles Source Type: research

Signal Changes in the Dentate Nucleus and Globus Pallidus on Unenhanced T1-Weighted Magnetic Resonance Images After Intrathecal Administration of Macrocyclic Gadolinium Contrast Agent
Conclusions Intrathecal macrocyclic GBCA administration was not associated with measurable T1 SI changes in the GP and DN as an indicator of brain gadolinium deposition detectable by MRI. (Source: Investigative Radiology)
Source: Investigative Radiology - August 8, 2018 Category: Radiology Tags: Original Articles Source Type: research

Impact of the Glymphatic System on the Kinetic and Distribution of Gadodiamide in the Rat Brain: Observations by Dynamic MRI and Effect of Circadian Rhythm on Tissue Gadolinium Concentrations
Conclusions Instantaneous transition of gadodiamide from blood to cerebrospinal fluid was indicated by dynamic MRI. The gadodiamide distribution to the cerebral cortex and deep cerebellar nuclei seemed to depend on both blood flow and cerebrospinal fluid. This confirms previous studies indicating that the cerebrospinal fluid is one potential pathway of gadolinium-based contrast agent entry into the brain. For the distribution and clearance of the gadodiamide from brain tissue, involvement of the glymphatic system seemed to be indicated in terms of the influence of sleep and anesthesia. (Source: Investigative Radiology)
Source: Investigative Radiology - August 8, 2018 Category: Radiology Tags: Original Articles Source Type: research

Multimodal Imaging Study of Gadolinium Presence in Rat Cerebellum: Differences Between Gd Chelates, Presence in the Virchow-Robin Space, Association With Lipofuscin, and Hypotheses About Distribution Pathway
Conclusions Transmission electron microscopy analysis of cerebellums of renally impaired rats repeatedly injected with gadobenate and gadodiamide revealed the presence of Gd. Spheroid Gd depositions consisting of a filamentous meshwork were observed in the wall of microvessels, in perivascular Virchow-Robin space, and in the interstitium. Gd was also found in choroid plexus and was associated with pigments (likely lipofuscin) in glial cells. This is consistent with the involvement of the glymphatic distribution pathway for GBCAs. No insoluble Gd deposits were detected in rats injected with the macrocyclic GBCA gadoterate...
Source: Investigative Radiology - August 8, 2018 Category: Radiology Tags: Original Articles Source Type: research

Methodological Aspects for Preclinical Evaluation of Gadolinium Presence in Brain Tissue: Critical Appraisal and Suggestions for Harmonization—A Joint Initiative
Gadolinium (Gd)-based contrast agents (GBCAs) are pharmaceuticals that have been approved for 30 years and used daily in millions of patients worldwide. Their clinical benefits are indisputable. Recently, unexpected long-term presence of Gd in the brain has been reported by numerous retrospective clinical studies and confirmed in preclinical models particularly after linear GBCA (L-GBCA) compared with macrocyclic GBCA (M-GBCA). Even if no clinical consequences of Gd presence in brain tissue has been demonstrated so far, in-depth investigations on potential toxicological consequences and the fate of Gd in the body remain cr...
Source: Investigative Radiology - August 8, 2018 Category: Radiology Tags: Review Article Source Type: research

Augmented Reality–Guided Lumbar Facet Joint Injections
Objectives The aim of this study was to assess feasibility and accuracy of augmented reality–guided lumbar facet joint injections. Materials and Methods A spine phantom completely embedded in hardened opaque agar with 3 ring markers was built. A 3-dimensional model of the phantom was uploaded to an augmented reality headset (Microsoft HoloLens). Two radiologists independently performed 20 augmented reality–guided and 20 computed tomography (CT)–guided facet joint injections each: for each augmented reality–guided injection, the hologram was manually aligned with the phantom container using the ...
Source: Investigative Radiology - July 4, 2018 Category: Radiology Tags: Technical Note Source Type: research

Photon Counting Computed Tomography With Dedicated Sharp Convolution Kernels: Tapping the Potential of a New Technology for Stent Imaging
Objectives The aims of this study were to assess the value of a dedicated sharp convolution kernel for photon counting detector (PCD) computed tomography (CT) for coronary stent imaging and to evaluate to which extent iterative reconstructions can compensate for potential increases in image noise. Materials and Methods For this in vitro study, a phantom simulating coronary artery stenting was prepared. Eighteen different coronary stents were expanded in plastic tubes of 3 mm diameter. Tubes were filled with diluted contrast agent, sealed, and immersed in oil calibrated to an attenuation of −100 HU simulating epi...
Source: Investigative Radiology - July 4, 2018 Category: Radiology Tags: Original Articles Source Type: research

Computed Tomography Perfusion Measurements in Renal Lesions Obtained by Bayesian Estimation, Advanced Singular-Value Decomposition Deconvolution, Maximum Slope, and Patlak Models: Intermodel Agreement and Diagnostic Accuracy of Tumor Classification
Conclusions Quantitative perfusion parameters obtained from different mathematical models cannot be used interchangeably. Based on BF and BV estimates, all models are a useful tool in the differential diagnosis of kidney tumors, with the Patlak plot model yielding a significantly lower diagnostic accuracy. (Source: Investigative Radiology)
Source: Investigative Radiology - July 4, 2018 Category: Radiology Tags: Original Articles Source Type: research

Subacute Infarct Volume With Edema Correction in Computed Tomography Is Equivalent to Final Infarct Volume After Ischemic Stroke: Improving the Comparability of Infarct Imaging Endpoints in Clinical Trials
Objectives Final infarct volume is regularly used as an end point of tissue outcome in stroke trials; however, the reported volumes are most commonly derived from early follow-up imaging. Those volumes are significantly impaired by ischemic edema, which causes an overestimation of the true final lesion volume. As net water uptake within ischemic brain can be quantified densitometrically in computed tomography (CT) as recently described, we hypothesized that the final lesion volume can be better estimated by correcting the lesion volume in early follow-up for the corresponding proportion of edema. Materials and Methods ...
Source: Investigative Radiology - July 4, 2018 Category: Radiology Tags: Original Articles Source Type: research

Performance of an Automated Versus a Manual Whole-Body Magnetic Resonance Imaging Workflow
Objectives The aim of this study was to evaluate the performance of an automated workflow for whole-body magnetic resonance imaging (WB-MRI), which reduces user interaction compared with the manual WB-MRI workflow. Materials and Methods This prospective study was approved by the local ethics committee. Twenty patients underwent WB-MRI for myopathy evaluation on a 3 T MRI scanner. Ten patients (7 women; age, 52 ± 13 years; body weight, 69.9 ± 13.3 kg; height, 173 ± 9.3 cm; body mass index, 23.2 ± 3.0) were examined with a prototypical automated WB-MRI workflow, which automatically segments t...
Source: Investigative Radiology - July 4, 2018 Category: Radiology Tags: Original Articles Source Type: research

Low-Dose Characterization of Kidney Stones Using Spectral Detector Computed Tomography: An Ex Vivo Study
Conclusions Spectral detector CT allows for differentiation of kidney stones using semi-automatic segmentation and advanced image post-processing, even in low-dose imaging protocols. (Source: Investigative Radiology)
Source: Investigative Radiology - July 4, 2018 Category: Radiology Tags: Original Articles Source Type: research

Quantification of Total and Intracellular Sodium Concentration in Primary Prostate Cancer and Adjacent Normal Prostate Tissue With Magnetic Resonance Imaging
Objectives The aim of this study was to measure the tissue sodium concentration (TSC) within tumors and normal prostate in prostate cancer patients, using prostatectomy as pathological criterion standard. Materials and Methods Fifteen patients with biopsy-proven, magnetic resonance imaging (MRI) visible, intermediate- or high-risk prostate cancer underwent a dedicated research sodium MRI, before treatment with radical prostatectomy. All participants signed written informed consent for this institutional review board–approved prospective study. 3 T MRI acquired using a dedicated multinuclear clamshell transmit co...
Source: Investigative Radiology - July 4, 2018 Category: Radiology Tags: Original Articles Source Type: research

Detection of Subsolid Nodules in Lung Cancer Screening: Complementary Sensitivity of Visual Reading and Computer-Aided Diagnosis
Objectives The aim of this study was to compare computer-aided diagnosis (CAD) and visual reading for the detection of subsolid nodules (SSNs) in volumetrl measuremic low-dose computed tomography (LDCT) for lung cancer screening. Materials and Methods Prospective visual detection (VD) and manuaent of SSN were performed in the 2303 baseline volumetric LDCTs of the Multicenter Italian Lung Detection trial. Baseline and 2- and 4-year LDCTs underwent retrospective CAD analysis, subsequently reviewed by 2 experienced thoracic radiologists. The reference standard was defined by the cumulative number of SSNs detected by any ...
Source: Investigative Radiology - July 4, 2018 Category: Radiology Tags: Original Articles Source Type: research

“X-Map 2.0” for Edema Signal Enhancement for Acute Ischemic Stroke Using Non–Contrast-Enhanced Dual-Energy Computed Tomography
Objectives A novel imaging technique (“X-map”) has been developed to identify acute ischemic lesions for stroke patients using non–contrast-enhanced dual-energy computed tomography (NE-DE-CT). Using the 3-material decomposition technique, the original X-map (“X-map 1.0”) eliminates fat and bone from the images, suppresses the gray matter (GM)-white matter (WM) tissue contrast, and makes signals of edema induced by severe ischemia easier to detect. The aim of this study was to address the following 2 problems with the X-map 1.0: (1) biases in CT numbers (or artifacts) near the skull of NE-DE-...
Source: Investigative Radiology - June 11, 2018 Category: Radiology Tags: Original Articles Source Type: research

Reduction of Artifacts Caused by Deep Brain Stimulating Electrodes in Cranial Computed Tomography Imaging by Means of Virtual Monoenergetic Images, Metal Artifact Reduction Algorithms, and Their Combination
Discussion The investigated O-MAR algorithm reduces artifacts from DBS electrodes and should be used in the assessment of postoperative patients; however, combination with VMI does not provide an additional benefit. (Source: Investigative Radiology)
Source: Investigative Radiology - June 11, 2018 Category: Radiology Tags: Original Articles Source Type: research

Pulmonary Function Diagnosis Based on Respiratory Changes in Lung Density With Dynamic Flat-Panel Detector Imaging: An Animal-Based Study
Objectives The aims of this study were to address the relationship between respiratory changes in image density of the lungs and tidal volume, to compare the changes between affected and unaffected lobes, and to apply this new technique to the diagnosis of atelectasis. Materials and Methods Our animal care committee approved this prospective animal study. Sequential chest radiographs of 4 pigs were obtained under respiratory control with a ventilator using a dynamic flat-panel detector system. Porcine models of atelectasis were developed, and the correlation between the tidal volume and changes in pixel values measure...
Source: Investigative Radiology - June 11, 2018 Category: Radiology Tags: Original Articles Source Type: research

Dual-Energy Computed Tomography–Based Display of Bone Marrow Edema in Incidental Vertebral Compression Fractures: Diagnostic Accuracy and Characterization in Oncological Patients Undergoing Routine Staging Computed Tomography
Purpose The aim of this study was to evaluate the diagnostic performance of virtual noncalcium (VNCa) dual-energy computed tomography (DECT) reconstructions enabling visualization of bone marrow edema for characterization of incidental thoracolumbar compression fractures in routine thoracoabdominal staging computed tomography (CT). Materials and Methods We retrospectively analyzed 51 oncological patients without suspected fracture or indicative complaints presenting at least 1 thoracolumbar compression fracture on routine thoracoabdominal staging DECT who had been examined between October 2015 and June 2017 using thir...
Source: Investigative Radiology - June 11, 2018 Category: Radiology Tags: Original Articles Source Type: research

[68Ga]Ga-Pentixafor PET/MRI for CXCR4 Imaging of Chronic Lymphocytic Leukemia: Preliminary Results
Objectives This prospective proof-of-principle study aimed to determine whether [68Ga]Ga-Pentixafor uptake, which reflects CXCR4 expression, is higher in the bone marrow of chronic lymphocytic leukemia (CLL) than in other oncological diseases without bone marrow infiltration and can therefore be used for CLL imaging. Materials and Methods Thirteen CLL patients and 20 controls (10 with pancreatic adenocarcinoma and 10 with mucosa-associated lymphoid tissue lymphoma) with histologically proven cancer underwent [68Ga]Ga-Pentixafor positron emission tomography/magnetic resonance imaging. Standardized [68Ga]Ga-Pentixafor u...
Source: Investigative Radiology - June 11, 2018 Category: Radiology Tags: Original Articles Source Type: research

Magnetization Transfer Ratio in Peripheral Nerve Tissue: Does It Depend on Age or Location?
Conclusion The MTR of lower extremity nerves shows no proximal-to-distal gradient in young healthy volunteers but decreases with age. For future studies using MTR in peripheral nerve disorders, these findings suggest that referencing magnetization transfer contrast values in terms of age, but not anatomical nerve location is required. (Source: Investigative Radiology)
Source: Investigative Radiology - June 11, 2018 Category: Radiology Tags: Original Articles Source Type: research

Assessment of Low-Grade Meniscal and Cartilage Damage of the Knee at 7 T: A Comparison to 3 T Imaging With Arthroscopic Correlation
This study was approved by the local ethics committee, and written informed consent was obtained from each patient. Forty-one patients with suspected meniscal damage or mild osteoarthritis (Kellgren-Lawrence score, 0–2) received 7 T as well as routine clinical 3 T consecutively. The imaging protocol at both field strengths consisted of PD-weighted imaging with more than doubled resolution at 7 T. Images were read blinded regarding field strength and patient characteristics by 3 readers with different experience in musculoskeletal MRI (3 years, 6 years, and 10 years) according to a modified whole-organ MRI score of th...
Source: Investigative Radiology - June 11, 2018 Category: Radiology Tags: Original Articles Source Type: research

Advocating the Development of Next-Generation High-Relaxivity Gadolinium Chelates for Clinical Magnetic Resonance
The question of improved relaxivity, and potential efficacy therein, for a next-generation of magnetic resonance gadolinium chelates with extracellular distribution and renal excretion, which could also be viewed from the perspective of dose, is addressed on the basis of historical development, animal experimentation, and human trials. There was no systematic evaluation that preceded the choice of 0.1 mmol/kg as the standard dose for human imaging with the gadolinium chelates. In part, this dose was chosen owing to bloodwork abnormalities seen in phase I and phase II studies. Animal investigations and early clinical trials...
Source: Investigative Radiology - June 11, 2018 Category: Radiology Tags: Review Article Source Type: research

Intravenous Calcium-/Zinc-Diethylene Triamine Penta-Acetic Acid in Patients With Presumed Gadolinium Deposition Disease: A Preliminary Report on 25 Patients
Objectives The aim of this study was to report the use of intravenous calcium (Ca)-/zinc (Zn)-diethylene triamine penta-acetic acid (DTPA) for the treatment of 25 symptomatic patients diagnosed with gadolinium deposition disease (GDD). Materials and Methods Written informed consent was obtained. Twenty-five patients (18 women; mean age, 46.8 ± 15.3 years) with a diagnosis of GDD were included. All patients had received at least 1 administration of a gadolinium (Gd)-based contrast agent. Patients received 3 treatment sessions with Ca-/Zn-DTPA, 15 with treatments spaced 1 month apart, and 10 with treatments space...
Source: Investigative Radiology - May 3, 2018 Category: Radiology Tags: Preliminary Report Source Type: research

Dose Efficiency of Quarter-Millimeter Photon-Counting Computed Tomography: First-in-Human Results
Conclusion High-resolution photon-counting CT in humans showed improved image quality in terms of spatial resolution and image noise compared with standard-resolution photon-counting. (Source: Investigative Radiology)
Source: Investigative Radiology - May 3, 2018 Category: Radiology Tags: Original Articles Source Type: research

Phenotypic Multiorgan Involvement of Subclinical Disease as Quantified by Magnetic Resonance Imaging in Subjects With Prediabetes, Diabetes, and Normal Glucose Tolerance
Introduction Detailed mechanisms in the pathophysiology of diabetes disease are poorly understood, but structural alterations in various organ systems incur an elevated risk for cardiovascular events and adverse outcome. The aim of this study was to compare multiorgan subclinical disease phenotypes by magnetic resonance (MR) imaging to study differences between subjects with prediabetes, diabetes, and normal controls. Materials and Methods Subjects without prior cardiovascular disease were enrolled in a prospective case-control study and underwent multiorgan MR for the assessment of metabolic and arteriosclerotic alte...
Source: Investigative Radiology - May 3, 2018 Category: Radiology Tags: Original Articles Source Type: research

Improved Detection of Foreign Bodies on Radiographs Using X-ray Dark-Field and Phase-Contrast Imaging
Purpose The aim of this study was to investigate whether the detection of foreign bodies can be improved using dark-field and phase-contrast radiography compared with conventional (transmission) radiographs. Materials and Methods Experiments were performed using ex vivo pig paws, which were prepared with differently sized foreign bodies of metal, wood, and glass (n = 10 each). Paws without foreign bodies served as controls (n = 30). All images were acquired using an experimental grating-based large object radiography system. Five blinded readers (second- to fourth-year radiology residents) were asked to assess the pre...
Source: Investigative Radiology - May 3, 2018 Category: Radiology Tags: Original Articles Source Type: research

Characterization of Small Renal Tumors With Magnetic Resonance Elastography: A Feasibility Study
Objectives The aim of this study was to explore the feasibility of magnetic resonance elastography (MRE) for characterizing indeterminate small renal tumors (SRTs) as part of a multiparametric magnetic resonance (MR) imaging protocol. Materials and Methods After institutional review board approval and informed consent were obtained, 21 prospective adults (15 men; median age, 55 years; age range, 25–72 years) with SRT were enrolled. Tumors (2–5 cm Ø) were imaged using 3-directional, gradient echo MRE. Viscoelastic parametric maps (shear wave velocity [c] and attenuation [α]) were analyzed by 2 ...
Source: Investigative Radiology - May 3, 2018 Category: Radiology Tags: Original Articles Source Type: research

Texture Analysis and Machine Learning for Detecting Myocardial Infarction in Noncontrast Low-Dose Computed Tomography: Unveiling the Invisible
Conclusions This study indicates the ability of texture analysis and machine learning in detecting MI on noncontrast low radiation dose CCT images being not visible for the radiologists' eye. (Source: Investigative Radiology)
Source: Investigative Radiology - May 3, 2018 Category: Radiology Tags: Original Articles Source Type: research

Gadolinium Retention, Brain T1 Hyperintensity, and Endogenous Metals: A Comparative Study of Macrocyclic Versus Linear Gadolinium Chelates in Renally Sensitized Rats
Objectives This preclinical study was designed to compare gadolinium (Gd) brain uptake after repeated injections of a macrocyclic Gd-based contrast agent (GBCA) (gadoterate meglumine) or 2 linear GBCAs (L-GBCAs) (gadobenate dimeglumine or gadodiamide) on a translational model of moderate renal impairment in rats. Methods The study was carried out in subtotally nephrectomized rats. Animals received 4 intravenous injections per week of GBCA (gadoterate meglumine, gadobenate dimeglumine, or gadodiamide) for 5 weeks, resulting in a cumulative dose of 12 mmol/kg, followed by a 1-month injection-free period. T1 hyperintensi...
Source: Investigative Radiology - May 3, 2018 Category: Radiology Tags: Original Articles Source Type: research

Comparison of Iodine Density Measurement Among Dual-Energy Computed Tomography Scanners From 3 Vendors
Conclusions Dual-energy CT systems and fluid characteristics did not have a significant effect on the IoD measurement accuracy. A cutoff of IoD for the determination of a truly enhancing lesion on DECT would be 0.4 mg/mL. (Source: Investigative Radiology)
Source: Investigative Radiology - May 3, 2018 Category: Radiology Tags: Original Articles Source Type: research

In Vivo Abdominal Magnetic Resonance Elastography for the Assessment of Portal Hypertension Before and After Transjugular Intrahepatic Portosystemic Shunt Implantation: Erratum
No abstract available (Source: Investigative Radiology)
Source: Investigative Radiology - April 5, 2018 Category: Radiology Tags: Erratum Source Type: research

Frequency and Severity of Acute Allergic-Like Reactions to Intravenously Administered Gadolinium-Based Contrast Media in Children
Conclusion Allergic-like reactions to GBCM in children are rare. Gadoterate meglumine has a reaction frequency that does not significantly differ from other GBCMs. During the transition from gadopentetate dimeglumine to gadoterate meglumine, an increase in the frequency of reported allergic-like reactions was observed, likely reflective of the Weber effect. (Source: Investigative Radiology)
Source: Investigative Radiology - April 5, 2018 Category: Radiology Tags: Original Articles Source Type: research

Optimizing Pulmonary Embolism Computed Tomography in the Age of Individualized Medicine: A Prospective Clinical Study
Conclusions Simultaneously optimizing both CM injections and kV settings to the individual patient in CTPA results in diagnostic attenuation with on average 24 to 38 mL of CM volume and a low radiation dose for most patients. This individualized protocol may help overcome attenuation-variation problems between patients and kV settings in CTPA. (Source: Investigative Radiology)
Source: Investigative Radiology - April 5, 2018 Category: Radiology Tags: Original Articles Source Type: research

CAPTURE: Consistently Acquired Projections for Tuned and Robust EstimationA Self-Navigated Respiratory Motion Correction Approach
In this study, we present a fully automated and robust self-navigated approach to obtain 4-dimensional (4-D) motion-resolved images during free breathing. Materials and Methods The proposed method, Consistently Acquired Projections for Tuned and Robust Estimation (CAPTURE), is a variant of the stack-of-stars gradient-echo sequence. A 1-D navigator was consistently acquired at a fixed azimuthal angle for all stacks of spokes to reduce nonphysiological signal contamination due to system imperfections. The resulting projections were then “tuned” using complex phase rotation to adapt to scan-to-scan variations, ...
Source: Investigative Radiology - April 5, 2018 Category: Radiology Tags: Original Articles Source Type: research

Treatment Effect of Balloon Pulmonary Angioplasty in Chronic Thromboembolic Pulmonary Hypertension Quantified by Automatic Comparative Imaging in Computed Tomography Pulmonary Angiography
Conclusions Comparative imaging analysis in CTEPH patients offers insight into differences in BPA treatment effect. Quantification of perfusion changes provides noninvasive measures that reflect hemodynamic changes. (Source: Investigative Radiology)
Source: Investigative Radiology - April 5, 2018 Category: Radiology Tags: Original Articles Source Type: research

Gadolinium Accumulation in the Deep Cerebellar Nuclei and Globus Pallidus After Exposure to Linear but Not Macrocyclic Gadolinium-Based Contrast Agents in a Retrospective Pig Study With High Similarity to Clinical Conditions
Conclusion Multiple exposure to macrocyclic gadobutrol is not associated with Gd deposition in brain tissue of healthy pigs. A single additional administration of linear Gd-DTPA is sufficient for Gd accumulation in the nucleus dentatus and globus pallidus, underlining the importance of obtaining a complete GBCA history in clinical studies. (Source: Investigative Radiology)
Source: Investigative Radiology - April 5, 2018 Category: Radiology Tags: Original Articles Source Type: research

T2 Mapping for Noninvasive Assessment of Interstitial Edema in Acute Cardiac Allograft Rejection in a Mouse Model of Heterotopic Heart Transplantation
Objectives Heart transplantation (HTX) in mice is used to characterize gene-deficient mice and to test new treatment strategies. The purpose was to establish noninvasive magnetic resonance imaging techniques in mice to monitor pathophysiological changes of the allograft during rejection. Materials and Methods Magnetic resonance imaging was performed at baseline and days 1 and 6 after isogenic (n = 10, C57BL/6) and allogenic (n = 12, C57BL/6 to BALB/c) heterotopic HTX on a 7 T small animal scanner. Respiratory- and electrocardiogram-gated multislice multi-echo spin echo sequences were acquired, and parameter maps of T2...
Source: Investigative Radiology - April 5, 2018 Category: Radiology Tags: Original Articles Source Type: research

Impact of Contrast Media Concentration on Low-Kilovolt Computed Tomography Angiography: A Systematic Preclinical Approach
Objectives Low peak kilovoltage (kVp) protocols in computed tomography angiography (CTA) demand a review of contrast media (CM) administration practices. The aim of this study was to systematically evaluate different iodine concentrations of CM in a porcine model. Materials and Methods Dynamic 70 kVp CTA was performed on 7 pigs using a third-generation dual-source CT system. Three CM injection protocols (A-C) with an identical total iodine dose and iodine delivery rate (150 mg I/kg, 12 s, 0.75 g I/s) differed in iodine concentration and flow rate (protocol A: 400 mg I/mL, 1.9 mL/s; B: 300 mg I/mL, 2.5 mL/s; C: 150 mg ...
Source: Investigative Radiology - April 5, 2018 Category: Radiology Tags: Original Articles Source Type: research

Relaxivity of Ferumoxytol at 1.5 T and 3.0 T
Conclusions Ferumoxytol demonstrates strong longitudinal and transverse relaxivities. Awareness of the nonlinear relaxation behavior of ferumoxytol in blood is important for ferumoxytol-enhanced magnetic resonance imaging applications and for protocol optimization. (Source: Investigative Radiology)
Source: Investigative Radiology - April 5, 2018 Category: Radiology Tags: Original Articles Source Type: research