Dynamic Contrast-Enhanced Magnetic Resonance Imaging Suggests Normal Perfusion in Normal-Appearing White Matter in Multiple Sclerosis
Objectives: Multiple sclerosis (MS) is a chronic, inflammatory disease of the central nervous system and has been associated with reduced perfusion in normal-appearing white matter (NAWM). The magnitude of this hypoperfusion is unclear. The present study aims to quantify NAWM perfusion with dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) in patients with relapsing-remitting (RR) MS and in a control group. Materials and Methods: The statistical power of a DCE-MRI acquisition to reveal hypoperfusion in MS was estimated using a Monte Carlo simulation: synthetic tissue curves with a contrast-to-noise ratio of...
Source: Investigative Radiology - February 9, 2017 Category: Radiology Tags: Original Articles Source Type: research

Extremely Small Pseudoparamagnetic Iron Oxide Nanoparticle as a Novel Blood Pool T1 Magnetic Resonance Contrast Agent for 3 T Whole-Heart Coronary Angiography in Canines: Comparison With Gadoterate Meglumine
Conclusions: The experimental blood pool agent KEG3 offers equivalent image quality for whole-heart coronary MRA at 3 T upon contrast administration and persistent better quality in the subsequent scans, compared with a traditional extracellular gadolinium-based contrast agent. (Source: Investigative Radiology)
Source: Investigative Radiology - January 10, 2017 Category: Radiology Tags: Original Articles Source Type: research

Hyperpolarized 129Xenon Magnetic Resonance Imaging to Quantify Regional Ventilation Differences in Mild to Moderate Asthma: A Prospective Comparison Between Semiautomated Ventilation Defect Percentage Calculation and Pulmonary Function Tests
Objectives: The aim of this study was to investigate ventilation in mild to moderate asthmatic patients and age-matched controls using hyperpolarized (HP) 129Xenon magnetic resonance imaging (MRI) and correlate findings with pulmonary function tests (PFTs). Materials and Methods: This single-center, Health Insurance Portability and Accountability Act–compliant prospective study was approved by our institutional review board. Thirty subjects (10 young asthmatic patients, 26 ± 6 years; 3 males, 7 females; 10 older asthmatic patients, 64 ± 6 years; 3 males, 7 females; 10 healthy controls) were enrolled. A...
Source: Investigative Radiology - January 10, 2017 Category: Radiology Tags: Original Articles Source Type: research

Quantitative Assessment of Liver Function Using Gadoxetate-Enhanced Magnetic Resonance Imaging: Monitoring Transporter-Mediated Processes in Healthy Volunteers
Conclusions: This is the first study that reports estimates for the hepatic uptake and efflux transport process of gadoxetate in healthy volunteers in vivo. The results highlight that dynamic contrast-enhanced MRI with gadoxetate can provide novel quantitative insights into liver function and may therefore prove useful in studies that aim to monitor liver pathology, as well as being an alternative approach for studying hepatic drug-drug interactions. (Source: Investigative Radiology)
Source: Investigative Radiology - January 10, 2017 Category: Radiology Tags: Original Articles Source Type: research

Dynamic Contrast-Enhanced Computed Tomography–Derived Blood Volume and Blood Flow Correlate With Patient Outcome in Metastatic Renal Cell Carcinoma
Conclusions: In patients with mRCC treated with angiogenesis inhibitors, the largest reductions in BV and BF between baseline and weeks 5 and 10 were associated with favorable outcomes. At baseline, the lowest BV and BF were associated with the poorest outcomes regardless of the subsequent treatment. Early reductions in PS were associated with favorable outcomes for those treated with angiogenesis inhibitors and with poor outcomes for those treated with immunotherapies. (Source: Investigative Radiology)
Source: Investigative Radiology - January 10, 2017 Category: Radiology Tags: Original Articles Source Type: research

The Use of Acoustic Radiation Force Decorrelation-Weighted Pulse Inversion for Enhanced Ultrasound Contrast Imaging
In this study, a novel acoustic radiation force (ARF)–based approach was developed for superior microbubble signal detection. The feasibility of this technique, termed ARF decorrelation-weighted PI (ADW-PI), was demonstrated in vivo using a subcutaneous mouse tumor model. Materials and Methods: Tumors were implanted in the hindlimb of C57BL/6 mice by subcutaneous injection of MC38 cells. Lipid-shelled microbubbles were conjugated to anti-VEGFR2 antibody and administered via bolus injection. An image sequence using ARF pulses to generate microbubble motion was combined with PI imaging on a Verasonics Vantage programm...
Source: Investigative Radiology - January 10, 2017 Category: Radiology Tags: Original Articles Source Type: research

Noise Texture Deviation: A Measure for Quantifying Artifacts in Computed Tomography Images With Iterative Reconstructions
Objectives: The aims of this study were to introduce the measure noise texture deviation as quantitative parameter for evaluating iterative reconstruction (IR)–specific artifacts in computed tomography (CT) images and to test whether IR-specific artifacts, quantified through this measure, are reduced in advanced modeled IR (ADMIRE) as compared with sinogram-affirmed IR (SAFIRE) images of the liver ex vivo and in patients with hypodense liver lesions. Materials and Methods: In the ex vivo study part, an abdominal phantom was used. In the institutional review board–approved in vivo study part, 40 consecutive pat...
Source: Investigative Radiology - January 10, 2017 Category: Radiology Tags: Original Articles Source Type: research

Dose Optimization for Computed Tomography Localizer Radiographs for Low-Dose Lung Computed Tomography Examinations
Discussion: Dose from LRs may contribute significantly to the total effective dose of low-dose CT examinations such as lung cancer screening. Optimal LR settings can reduce LR dose substantially, but adaptations have to consider scanner characteristics, detector technology, and patient size. Thus, for low-dose CT examinations, such as cardiac examinations and lung cancer screening, LR optimization may result in a significant dose reduction and thereby in a substantial reduction of total dose. (Source: Investigative Radiology)
Source: Investigative Radiology - January 10, 2017 Category: Radiology Tags: Technical Note Source Type: research

Differentiation of Osteophytes and Disc Herniations in Spinal Radiculopathy Using Susceptibility-Weighted Magnetic Resonance Imaging
Conclusions: Susceptibility-weighted magnetic resonance imaging enables the reliable differentiation of osteophytes and disc herniations in patients with spinal radiculopathy with a higher sensitivity and specificity compared with conventional T1/T2 MR sequences. (Source: Investigative Radiology)
Source: Investigative Radiology - January 10, 2017 Category: Radiology Tags: Original Article Source Type: research

Validation of Interstitial Fractional Volume Quantification by Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging in Porcine Skeletal Muscles
Conclusions: Owing to more fitting parameters, the 2CXM yielded better fits and the median interstitium-to-plasma rate constant kep was less depending on the AD; however, the uncertainty expressed by the 25% to 75% quartile range was found to be larger. An AD of 10 minutes was needed for the 2CXM to achieve accuracy comparable to those of the TMs with shorter ADs. (Source: Investigative Radiology)
Source: Investigative Radiology - December 13, 2016 Category: Radiology Tags: Original Articles Source Type: research

Improving CT-Based PET Attenuation Correction in the Vicinity of Metal Implants by an Iterative Metal Artifact Reduction Algorithm of CT Data and Its Comparison to Dual-Energy–Based Strategies: A Phantom Study
Objective: The aim of this study was to evaluate the potential of iterative metal artifact reduction (IMAR) for the improvement of computed tomography (CT)–based position emission tomography (PET) attenuation correction in the vicinity of metal implants and compare it with dual-energy–based metal artifact reduction strategies. Methods: A dedicated dental phantom was constructed consisting of a cylindrical tube filled with [18-F]FDG solution (5300 mL and 50.9 MBq) containing 2 artificial jaws with 1 nonprecious alloy fixed dental prosthesis and 3 single tooth crowns in the lower jaw. Computed tomography measur...
Source: Investigative Radiology - December 13, 2016 Category: Radiology Tags: Original Articles Source Type: research

Gadobutrol in Renally Impaired Patients: Results of the GRIP Study
Conclusions: No safety concerns with gadobutrol in patients with moderate to severe renal impairment were identified. There were no NSF cases. (Source: Investigative Radiology)
Source: Investigative Radiology - December 13, 2016 Category: Radiology Tags: Original Articles Source Type: research

Comparison of Routine Knee Magnetic Resonance Imaging at 3 T and 7 T
Conclusions: Ultra-high-field MRI at 7 T improved the overall diagnostic confidence in routine MRI of the knee joint compared with that at 3 T. This is especially true for small joint structures and subtle lesions. Higher spatial resolution was identified as the main reason for this improvement. (Source: Investigative Radiology)
Source: Investigative Radiology - December 13, 2016 Category: Radiology Tags: Original Articles Source Type: research

Dual-Energy Computed Tomography for the Characterization of Intracranial Hemorrhage and Calcification: A Systematic Approach in a Phantom System
Conclusions: We define the optimal scan parameters and expected limitations for the accurate classification of hemorrhagic versus calcific cerebral lesions in an anthropomorphic phantom with DECT. Although our proposed DECT protocol represents an increase in dose compared with routine brain CT, this method is intended as a specialized evaluation of potential brain hemorrhage and is thus counterbalanced by increased diagnostic benefit. This work provides justification for the application of this technique in human clinical trials. (Source: Investigative Radiology)
Source: Investigative Radiology - December 13, 2016 Category: Radiology Tags: Original Articles Source Type: research

Magnetic Resonance Imaging Findings After Percutaneous Irreversible Electroporation of Liver Metastases: A Systematic Longitudinal Study
This study is an institutional review board–approved prospective longitudinal follow-up study on 27 patients with 37 liver metastases who underwent computed tomography–guided percutaneous IRE and a standardized follow-up protocol by serial hepatic MR imaging studies that consisted of a gadobutrol-enhanced dynamic series, axial T2-weighted (T2w) turbo spin echo, and diffusion-weighted imaging (b = 0/50/800), acquired before, within 2, and at 24 hours after IRE; at 1, 2, 4, 6, 8, and 12 weeks after IRE; and every 3 months thereafter for a follow-up of at least 12 months. Results: The ablated target lesion remain...
Source: Investigative Radiology - December 13, 2016 Category: Radiology Tags: Original Articles Source Type: research

Metal Artifact Reduction in Computed Tomography After Deep Brain Stimulation Electrode Placement Using Iterative Reconstructions
Objectives: Diagnostic accuracy of intraoperative computed tomography (CT) after deep brain stimulation (DBS) electrode placement is limited due to artifacts induced by the metallic hardware, which can potentially mask intracranial postoperative complications. Different metal artifact reduction (MAR) techniques have been introduced to reduce artifacts from metal hardware in CT. The purpose of this study was to assess the impact of a novel iterative MAR technique on image quality and diagnostic performance in the follow-up of patients with DBS electrode implementation surgery. Materials and Methods: Seventeen patients who ...
Source: Investigative Radiology - December 13, 2016 Category: Radiology Tags: Original Articles Source Type: research

Speed in Clinical Magnetic Resonance
Abstract: The relevant clinical accelerated magnetic resonance techniques that are available currently for routine patient examinations are reviewed, presenting and discussing the benefits therein when compared with more conventional scans. The focus is on clinical use and practicality, with the review divided into 3 sections. Improvements in 3-dimensional acquisition are first discussed, specifically controlled aliasing in parallel imaging results in higher acceleration, related radial techniques, and CAIPI-Dixon-TWIST-VIBE. Simultaneous multislice imaging is then reviewed, focusing on current implementation for 2-dimensi...
Source: Investigative Radiology - December 13, 2016 Category: Radiology Tags: Review Article Source Type: research

Iodine Concentration and Optimization in Computed Tomography Angiography: Current Issues
Abstract: Computed tomography (CT) technology has seen a dramatic evolution in the recent past that has deeply changed the face of this diagnostic modality. Since the early days of helical single-slice and then multislice CT, CT angiography (CTA) has been one of the most technically demanding applications, both in terms of scanning technique and contrast medium (CM) injection protocol, due to the need to acquire a large amount of high-resolution data over a limited period corresponding to the peak contrast enhancement of the arterial system. Iodine concentration is one of the main determinants of arterial enhancement in CT...
Source: Investigative Radiology - November 10, 2016 Category: Radiology Tags: Original Articles Source Type: research

Patient Comfort During Contrast Media Injection in Coronary Computed Tomographic Angiography Using Varying Contrast Media Concentrations and Flow Rates: Results From the EICAR Trial
Conclusions: High flow rates of prewarmed CM were safely injected without discomfort, pain, or stress. Therefore, the use of high flow rates should not be considered a drawback for CM administration in clinical practice. (Source: Investigative Radiology)
Source: Investigative Radiology - November 10, 2016 Category: Radiology Tags: Original Articles Source Type: research

Acute Kidney Injury After Intravenous Versus Intra-Arterial Contrast Material Administration in a Paired Cohort
Conclusions: Intra-arterial administration of contrast material during cardiac catheterization had a similar risk of AKI as compared with that of CT scanning involving IV administration in a cohort of patients who underwent both procedures. These findings suggest that previously reported much higher rates of AKI after cardiac catheterization compared with that of IV contrast administration reflect higher baseline clinical risk factors for AKI in the former cohort compared with that in the latter. (Source: Investigative Radiology)
Source: Investigative Radiology - November 10, 2016 Category: Radiology Tags: Original Articles Source Type: research

Clinical Significance of Persistent Global and Focal Computed Tomography Nephrograms After Cardiac Catheterization and Their Relationships to Urinary Biomarkers of Kidney Damage and Procedural Factors: Pilot Study
Conclusions: Global nephrograms on unenhanced CT in patients who have undergone CC are significantly correlated with changes in urinary biomarkers for kidney damage. (Source: Investigative Radiology)
Source: Investigative Radiology - November 10, 2016 Category: Radiology Tags: Original Articles Source Type: research

A Proposed Computed Tomography Contrast Agent Using Carboxybetaine Zwitterionic Tantalum Oxide Nanoparticles: Imaging, Biological, and Physicochemical Performance
Conclusions: We found that a CZ-TaO NP-based contrast agent is potentially viable for general-purpose clinical CT imaging. Our results suggest that such an agent can be formulated with clinically viable physicochemical properties, can be biologically safe and cleared rapidly in urine, and can provide substantially improved image contrast at CT compared with current iodinated agents. (Source: Investigative Radiology)
Source: Investigative Radiology - November 10, 2016 Category: Radiology Tags: Original Articles Source Type: research

Characterization of a Novel Hafnium-Based X-ray Contrast Agent
Conclusions: The profile of BAY-576 indicates its potential as the first compound in a new class of noniodine x-ray contrast agents, which can contribute to the reduction of the radiation burden in contrast-enhanced CT imaging. (Source: Investigative Radiology)
Source: Investigative Radiology - November 10, 2016 Category: Radiology Tags: Original Articles Source Type: research

Molecular Ultrasound Imaging of αvβ3-Integrin Expression in Carotid Arteries of Pigs After Vessel Injury
Objectives: Interventions such as balloon angioplasty can cause vascular injury leading to platelet activation, thrombus formation, and inflammatory response. This induces vascular smooth muscle cell activation and subsequent re-endothelialization with expression of αvβ3-integrin by endothelial cells and vascular smooth muscle cell. Thus, poly-N-butylcyanoacrylate microbubbles (MBs) targeted to αvβ3-integrin were evaluated for monitoring vascular healing after vessel injury in pigs using molecular ultrasound imaging. Materials and Methods: Approval for animal experiments was obtained. The binding spe...
Source: Investigative Radiology - November 10, 2016 Category: Radiology Tags: Original Articles Source Type: research

Ultra–Low-Dose Ultrasound Molecular Imaging for the Detection of Angiogenesis in a Mouse Murine Tumor Model: How Little Can We See?
The objective of this study was to evaluate the minimum microbubble dose for ultrasound molecular imaging to achieve statistically significant detection of angiogenesis in a mouse model. Materials and Methods: The preburst minus postburst method was implemented on a Verasonics ultrasound research scanner using a multiframe compounding pulse inversion imaging sequence. Biotinylated lipid (distearoyl phosphatidylcholine–based) microbubbles that were conjugated with antivascular endothelial growth factor 2 (VEGFR2) antibody (MBVEGFR2) or isotype control antibody (MBControl) were injected into mice carrying adenocarcino...
Source: Investigative Radiology - November 10, 2016 Category: Radiology Tags: Original Articles Source Type: research

The Father of Nonionic Contrast Media Professor Torsten Almén, MD, PhD (1931–2016)
No abstract available (Source: Investigative Radiology)
Source: Investigative Radiology - November 10, 2016 Category: Radiology Tags: In Memoriam Source Type: research

αvß3-Integrin–Targeted Magnetic Resonance Imaging for the Assessment of Early Antiangiogenic Therapy Effects in Orthotopic Breast Cancer Xenografts
Objectives: The aim of this study was to investigate magnetic resonance imaging (MRI) with αvß3-integrin–targeted ultrasmall superparamagnetic iron oxide nanoparticles (RGD-USPIO) for the in vivo monitoring of early antiangiogenic therapy effects in experimental breast cancer. Materials and Methods: Orthotopic human breast cancer (MDA-MB-231) xenograft-bearing severe combined immunodeficiency mice were imaged before and after a 1-week therapy with the vascular endothelial growth factor receptor-antibody bevacizumab or placebo (n = 10 per group, daily intraperitoneal injections of bevacizumab or a volume-...
Source: Investigative Radiology - October 12, 2016 Category: Radiology Tags: Original Articles Source Type: research

Iron(III)-Based Magnetic Resonance–Imageable Liposomal T1 Contrast Agent for Monitoring Temperature-Induced Image-Guided Drug Delivery
Conclusions: Doxorubicin-loaded and Fe-SDFO–loaded TSLs displayed favorable release and stability characteristics in vitro. An in vivo proof-of-concept study showed the feasibility of monitoring drug release using the newly designed iron(III)-based CA loaded TSLs. The measured R1-contrast change correlated with the amount of doxorubicin delivered to the tumor. Moreover, the pattern of R1 change could elucidate the pattern of drug release across the tumor. This new iron(III)-based liposomal MR CA is a promising alternative to comparable Gd-based systems. (Source: Investigative Radiology)
Source: Investigative Radiology - October 12, 2016 Category: Radiology Tags: Original Articles Source Type: research

Assessment of Orthotopic Liver Transplant Graft Survival on Gadoxetic Acid–Enhanced Magnetic Resonance Imaging Using Qualitative and Quantitative Parameters
Objective: The aim of this study was to evaluate the prognostic potential of a 3-parameter visual scoring (qualitative score [QS]) system for hepatobiliary phase gadoxetic acid–enhanced magnetic resonance imaging (MRI) in orthotopic liver transplant grafts. Materials and Methods: This retrospective study of 128 patients was approved by our institutional review board. Two readers independently assigned 3 QSs to T1-weighted MRI scans, 20 minutes after the administration of gadoxetic acid (hepatobiliary phase), based upon the following: (1) liver parenchymal enhancement (EnQS, 0–2); (2) biliary contrast excretion...
Source: Investigative Radiology - October 12, 2016 Category: Radiology Tags: Original Articles Source Type: research

Model-Based Characterization of the Transpulmonary Circulation by Dynamic Contrast-Enhanced Magnetic Resonance Imaging in Heart Failure and Healthy Volunteers
Objectives: Novel quantitative measures of transpulmonary circulation status may allow the improvement of heart failure (HF) patient management. In this work, we propose a method for the assessment of the transpulmonary circulation using measurements from indicator time intensity curves, derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) series. The derived indicator dilution parameters in healthy volunteers (HVs) and HF patients were compared, and repeatability was assessed. Furthermore, we compared the parameters derived using the proposed method with standard measures of cardiovascular function,...
Source: Investigative Radiology - October 12, 2016 Category: Radiology Tags: Original Articles Source Type: research

“One-Stop Shop”: Free-Breathing Dynamic Contrast-Enhanced Magnetic Resonance Imaging of the Kidney Using Iterative Reconstruction and Continuous Golden-Angle Radial Sampling
Conclusions: Dynamic, motion-suppressed contrast-enhanced renal MRI can be performed in high diagnostic quality during free breathing using a combination of golden-angle radial sampling, parallel imaging, and compressed sensing. Both morphologic and quantitative functional information can be acquired within a single acquisition. (Source: Investigative Radiology)
Source: Investigative Radiology - October 12, 2016 Category: Radiology Tags: Original Articles Source Type: research

Time-of-Arrival Parametric Maps and Virtual Bolus Images Derived From Contrast-Enhanced Time-Resolved Radial Magnetic Resonance Angiography Improve the Display of Brain Arteriovenous Malformation Vascular Anatomy
Conclusions: TOA-enhanced HFMRA provides serial images and time of arrival maps in one inclusive display. In this study, TOA mapping combined with Virtual Bolus imaging improved diagnostic confidence in AVM patients and facilitated arteriovenous separation. The VB method further reduced overlap of arterial and venous structures. (Source: Investigative Radiology)
Source: Investigative Radiology - October 12, 2016 Category: Radiology Tags: Original Articles Source Type: research

Incidence of Nephrogenic Systemic Fibrosis Using Gadobenate Dimeglumine in 1423 Patients With Renal Insufficiency Compared With Gadodiamide
Objective: The purpose of this study was to assess the incidence of nephrogenic systemic fibrosis (NSF) before and after educational interventions, implementation of a clinical screening process, and change to gadobenate dimeglumine in patients who had an estimated glomerular filtration rate (eGFR) of 30 mL/min per 1.72 m2 or less. Methods: This is a Health Insurance Portability and Accountability Act compliant, institutional review board exempt study. Two periods were studied—July 2005 to June 2006, during which gadodiamide was utilized as our magnetic resonance (MR) contrast agent, and November 2006 to August 2014...
Source: Investigative Radiology - October 12, 2016 Category: Radiology Tags: Original Articles Source Type: research

Revisiting the Pharmacokinetic Profiles of Gadolinium-Based Contrast Agents: Differences in Long-Term Biodistribution and Excretion
Conclusions: Using a nonconventional pharmacokinetic approach, we showed that gadoterate meglumine undergoes a much faster residual excretion from the body than the linear GBCAs, a process that seems related to the thermodynamic stability of the different chelates. Gadolinium dissociation occurs in vivo for some linear chelates, a mechanism that may explain their long-term retention and slow release from bone. Potential consequences in terms of bone toxicity warrant further investigations. (Source: Investigative Radiology)
Source: Investigative Radiology - October 12, 2016 Category: Radiology Tags: Original Articles Source Type: research

Intraindividual Analysis of Signal Intensity Changes in the Dentate Nucleus After Consecutive Serial Applications of Linear and Macrocyclic Gadolinium-Based Contrast Agents
Purpose: Recent studies reported an increase in the dentate nucleus (DN)-to-pons signal intensity (SI) ratio (DN-pons SI ratio) on unenhanced T1-weighted images in patients who received consecutive serial injections of linear gadolinium-based contrast agents (GBCAs). In contrast, most studies found no increase in the DN-pons SI ratio when patients were treated with consecutive serial injections of macrocyclic GBCAs. However, the potential difference between macrocyclic and linear GBCAs has never been assessed in individuals who received subsequent applications of both contrast agents. In this retrospective study, we assess...
Source: Investigative Radiology - October 12, 2016 Category: Radiology Tags: Original Articles Source Type: research

Effect of Renal Function on Gadolinium-Related Signal Increases on Unenhanced T1-Weighted Brain Magnetic Resonance Imaging
Objectives: The purpose of this study was to determine if renal function affects signal changes in the deep brain nuclei on unenhanced T1-weighted images after administration of linear gadolinium-based contrast agents (GBCAs). Methods: An electronic medical records search of 2 large medical centers identified 25 patients who received linear GBCA while on hemodialysis and had unenhanced T1-weighted images of the brain before and after. The dentate-to-cerebellar peduncle (DCP) ratio, globus pallidus-to-mid thalamus (GPT) ratio, and choroid plexus-to-nearby white matter ratio were measured and compared with 25 age/sex/GBCA e...
Source: Investigative Radiology - October 12, 2016 Category: Radiology Tags: Original Articles Source Type: research

Compressed Sensing SEMAC: 8-fold Accelerated High Resolution Metal Artifact Reduction MRI of Cobalt-Chromium Knee Arthroplasty Implants
Objective: The aim of this study was to prospectively test the hypothesis that a compressed sensing–based slice encoding for metal artifact correction (SEMAC) turbo spin echo (TSE) pulse sequence prototype facilitates high-resolution metal artifact reduction magnetic resonance imaging (MRI) of cobalt-chromium knee arthroplasty implants within acquisition times of less than 5 minutes, thereby yielding better image quality than high-bandwidth (BW) TSE of similar length and similar image quality than lengthier SEMAC standard of reference pulse sequences. Materials and Methods: This prospective study was approved by our...
Source: Investigative Radiology - September 9, 2016 Category: Radiology Tags: Original Articles Source Type: research

Presumed Gadolinium Toxicity in Subjects With Normal Renal Function: A Report of 4 Cases
Conclusions: Gadolinium toxicity may occur in subjects with normal renal function. Central torso and peripheral arm and leg distribution pain were common features. Distal arm and leg skin thickening and rubbery subcutaneous tissue were seen in late stages. Clouded mentation is also common. Vigilance to identify additional cases and investigate strategies for prevention and treatment is warranted to increase even further the safety of a very safe diagnostic procedure, GBCA-enhanced magnetic resonance imaging. (Source: Investigative Radiology)
Source: Investigative Radiology - September 9, 2016 Category: Radiology Tags: Original Articles Source Type: research

Impact of Impaired Renal Function on Gadolinium Retention After Administration of Gadolinium-Based Contrast Agents in a Mouse Model
Objectives: The aim of this study was to investigate the impact of impaired renal function on gadolinium (Gd) retention in various organs after Gd-based contrast agent injection. Materials and Methods: After local animal care and review committee approval, 23 normal mice and 26 with renal failure were divided into 4 treatment groups (Gd-DTPA-BMA, 5 mmol/kg; Gd-DOTA, 5 mmol/kg; GdCl3, 0.02 mmol/kg; and saline, 250 μL). Each agent was intravenously administered on weekdays for 4 weeks. Samples were collected on days 3 (short-term) and 45 (long-term) after the last injection. Gadolinium concentrations were quantified by i...
Source: Investigative Radiology - September 9, 2016 Category: Radiology Tags: Original Articles Source Type: research

Image Quality of a Novel Frequency Selective Nonlinear Blending Algorithm: An Ex Vivo Phantom Study in Comparison to Single-Energy Acquisitions and Dual-Energy Acquisitions With Monoenergetic Reconstructions
Conclusions: The new frequency split nonlinear blending algorithm with fixed settings offers a superior differentiation of contrast levels from low- to high-contrast settings. Using the optimal settings, this algorithm shows an equivalent contrast enhancement when compared with SECT70kV. Because of the non–DECT-based algorithm of BC, the new method of contrast enhancement seems to be particularly valuable for implementation in CT systems not equipped for dual-energy or spectral CT imaging. (Source: Investigative Radiology)
Source: Investigative Radiology - September 9, 2016 Category: Radiology Tags: Original Articles Source Type: research

Systematic Evaluation of Amide Proton Chemical Exchange Saturation Transfer at 3 T: Effects of Protein Concentration, pH, and Acquisition Parameters
Conclusions: Amide proton transfer–CEST imaging is a highly reproducible method in which absolute signal differences of approximately 0.5% are detectable in principle. For in vivo applications, Fourier or sSpline interpolations of z-spectra are preferable. Using reduced data sets delivers similar results but with increased variation and therefore decreased (pH/concentration) differentiation capability. Differentiation capability increases with increases in the saturation duration and power level. The results from the in vitro BSA system cannot be directly transferred to the in vivo situation due to different chemical...
Source: Investigative Radiology - September 9, 2016 Category: Radiology Tags: Original Articles Source Type: research

Hybrid Positron Emission Tomography/Magnetic Resonance Imaging: Challenges, Methods, and State of the Art of Hardware Component Attenuation Correction
Abstract: Attenuation correction (AC) is an essential step in the positron emission tomography (PET) data reconstruction process to provide accurate and quantitative PET images. The introduction of PET/magnetic resonance (MR) hybrid systems has raised new challenges but also possibilities regarding PET AC. While in PET/computed tomography (CT) imaging, CT images can be converted to attenuation maps, MR images in PET/MR do not provide a direct relation to attenuation. For the AC of patient tissues, new methods have been suggested, for example, based on image segmentation, atlas registration, or ultrashort echo time MR seque...
Source: Investigative Radiology - September 9, 2016 Category: Radiology Tags: Review Article Source Type: research

Dual-Energy Computed Tomography Angiography of the Head and Neck With Single-Source Computed Tomography: A New Technical (Split Filter) Approach for Bone Removal
Conclusions: Our results suggest that bone removal in DE-CTA of the head and neck vessels with a single-source CT is feasible and can be performed within acceptable time and moderate user interaction. (Source: Investigative Radiology)
Source: Investigative Radiology - September 9, 2016 Category: Radiology Tags: Original Articles Source Type: research

Three-Dimensional CAIPIRINHA SPACE TSE for 5-Minute High-Resolution MRI of the Knee
Objective: The aim of this study was to prospectively test the hypothesis that a 2-dimensional (2D) CAIPIRINHA (controlled aliasing in parallel imaging results in higher acceleration) sampling pattern facilitates 5-minute high spatial resolution 3-dimensional (3D) sampling perfection with application optimized contrast using different flip angle evolutions (SPACE) magnetic resonance imaging (MRI) of the knee with image quality similar or better than current 2D turbo spin echo (TSE) and 3D SPACE standards. Materials and Methods: The study was approved by our institutional review board. Twenty asymptomatic subjects (12 men,...
Source: Investigative Radiology - September 9, 2016 Category: Radiology Tags: Original Articles Source Type: research

Improved Detection of Recurrent Hepatocellular Carcinomas in Arterial Phase With CAIPIRINHA-Dixon-TWIST-Volumetric Interpolated Breath-Hold Examination
Purpose: The aim of this study was to assess the detection rate of recurrent hepatocellular carcinoma (HCC) in arterial phase using multiarterial CAIPIRINHA-Dixon-TWIST-VIBE (MA-CDT-VIBE). Materials and Methods: Fifty-eight patients with possible recurrence of HCC were retrospectively included in this cohort. Patients were scanned with a prototype dynamic contrast-enhanced breath-hold CDT-VIBE sequence, which included 6 arterial subphases with a temporal resolution of 2.64 seconds on a 3 T scanner. Absence and presence of recurrence was documented by consensus of 2 experienced radiologists using magnetic resonance imaging...
Source: Investigative Radiology - September 9, 2016 Category: Radiology Tags: Original Articles Source Type: research

Facilitated Diagnosis of Pneumothoraces in Newborn Mice Using X-ray Dark-Field Radiography
Objective: The aim of this study was to evaluate the diagnostic value of x-ray dark-field imaging in projection radiography-based depiction of pneumothoraces in the neonatal murine lung, a potentially life-threatening medical condition that requires a timely and correct diagnosis. Materials and Methods: By the use of a unique preclinical model, 7-day-old C57Bl/6N mice received mechanical ventilation for 2 or 8 hours with oxygen-rich gas (FIO2 = 0.4; n = 24). Unventilated mice either spontaneously breathed oxygen-rich gas (FIO2 = 0.4) for 2 or 8 hours or room air (n = 22). At the end of the experiment, lungs were inflated ...
Source: Investigative Radiology - September 9, 2016 Category: Radiology Tags: Original Articles Source Type: research

Multifrequency Magnetic Resonance Elastography for the Assessment of Renal Allograft Function
Objective: The aim of this study was to apply multifrequency magnetic resonance elastography (MMRE) for assessment of kidney function based on renal stiffness of allografts in transplant recipients and native kidneys in controls. Methods: In this prospective study, MMRE was used to measure stiffness in transplant kidneys in 22 recipients (age range, 23–73 years; 7 females) and in native kidneys in 11 controls (age range, 26–55 years; 4 females) after internal review board approval. The MMRE was performed on a 1.5 T magnetic resonance imaging scanner using 4 vibration frequencies from 40 to 70 Hz. Stiffness map...
Source: Investigative Radiology - August 11, 2016 Category: Radiology Tags: Original Articles Source Type: research

Comprehensive Comparison of Virtual Monoenergetic and Linearly Blended Reconstruction Techniques in Third-Generation Dual-Source Dual-Energy Computed Tomography Angiography of the Thorax and Abdomen
Objectives: The aim of this study was to perform an objective and subjective image analysis of traditional and advanced noise-optimized virtual monoenergetic imaging (VMI) algorithms and standard linearly blended images in third-generation dual-source dual-energy computed tomography angiography (DE-CTA) of the thorax and abdomen. Materials and Methods: Thoracoabdominal DE-CTA examinations of 55 patients (36 male; mean age, 64.2 ± 12.7 years) were included in this retrospective institutional review board–approved study. Dual-energy computed tomography angiography data were reconstructed using standard linearly...
Source: Investigative Radiology - August 11, 2016 Category: Radiology Tags: Original Articles Source Type: research

Magnetic Resonance Elastography of the Liver: Qualitative and Quantitative Comparison of Gradient Echo and Spin Echo Echoplanar Imaging Sequences
Objective: The aim of this study was to compare 2-dimensional (2D) gradient recalled echo (GRE) and 2D spin echo echoplanar imaging (SE-EPI) magnetic resonance elastography (MRE) sequences of the liver in terms of image quality and quantitative liver stiffness (LS) measurement. Materials and Methods: This prospective study involved 50 consecutive subjects (male/female, 33/17; mean age, 58 years) who underwent liver magnetic resonance imaging at 3.0 T including 2 MRE sequences, 2D GRE, and 2D SE-EPI (acquisition time 56 vs 16 seconds, respectively). Image quality scores were assessed by 2 independent observers based on wav...
Source: Investigative Radiology - August 11, 2016 Category: Radiology Tags: Original Articles Source Type: research

Temporal Changes of Texture Features Extracted From Pulmonary Nodules on Dynamic Contrast-Enhanced Chest Computed Tomography: How Influential Is the Scan Delay?
Conclusions: Most texture features exhibited stability with low variation between 60 and 150 seconds on DCE-CT. Thus, texture features extracted from contrast-enhanced CT with a scan delay range of 60 to 150 seconds can be used for tumor characterization despite the heterogeneity in delay time. (Source: Investigative Radiology)
Source: Investigative Radiology - August 11, 2016 Category: Radiology Tags: Original Articles Source Type: research