Evaluation of an AI-Based Detection Software for Acute Findings in Abdominal Computed Tomography Scans: Toward an Automated Work List Prioritization of Routine CT Examinations
Conclusions The algorithm's autonomous detection of acute pathological abdominal findings demonstrated a high diagnostic performance, enabling guidance of the radiology workflow toward prioritization of abdominal CT examinations with acute conditions. (Source: Investigative Radiology)
Source: Investigative Radiology - December 7, 2018 Category: Radiology Tags: Technical Notes Source Type: research

Diffusion Tensor Imaging of Healthy Skeletal Muscles: A Comparison Between 7 T and 3 T
Objective The aim of this study was to assess and compare the overall performance, reliability, variability, as well as the accuracy of diffusion tensor imaging (DTI) and fiber tracking metrics, for the muscles of the calf at 3 T and 7 T. Materials and Methods Ten volunteers (5 males; mean age, 29.1 ± 4.7 years), with no history of muscle disease, were examined twice at 3 T and 7 T, using a stimulated-echo acquisition mode DTI sequence. Signal-to-noise ratio (SNR) and DTI metrics (track numbers [trn], length [trl], volume [trv], fractional anisotropy [FA], mean [MD], axial [AD], and radial diffusivity [RD]) of ...
Source: Investigative Radiology - December 7, 2018 Category: Radiology Tags: Technical Notes Source Type: research

Linearity, Bias, Intrascanner Repeatability, and Interscanner Reproducibility of Quantitative Multidynamic Multiecho Sequence for Rapid Simultaneous Relaxometry at 3 T: A Validation Study With a Standardized Phantom and Healthy Controls
Conclusions Quantitative values derived from the MDME sequence are overall robust for brain relaxometry and volumetry on 3 T scanners from different vendors. Caution is warranted when applying MDME sequence on anatomies with relaxometry values outside the range of those typically observed in brain tissue. (Source: Investigative Radiology)
Source: Investigative Radiology - December 7, 2018 Category: Radiology Tags: Original Articles Source Type: research

Ultrashort Time-to-Echo Magnetic Resonance Imaging at 3 T for the Detection of Spondylolysis in Cadaveric Spines: Comparison With CT
The objective of this study was to compare the diagnostic performance and confidence of conventional, optimized, and ultrashort time to echo (UTE) magnetic resonance (MR) protocols for detection of simulated lumbar spondylolysis in human cadavers. In addition, we sought to demonstrate the feasibility of the UTE technique in subjects with and without spondylolysis. Materials and Methods Four human lumbar spine specimens with 46 individual pars interarticularis were randomly left intact (n = 26) or received experimental osteotomy (n = 20) using a microsurgical saw to simulate spondylolysis. The specimens were imaged using...
Source: Investigative Radiology - December 7, 2018 Category: Radiology Tags: Original Articles Source Type: research

Improved Visualization of Juxtaprosthetic Tissue Using Metal Artifact Reduction Magnetic Resonance Imaging: Experimental and Clinical Optimization of Compressed Sensing SEMAC
Conclusions Optimized advanced acceleration and reconstruction algorithms of CS-SEMAC have been identified to reduce metal artifacts in patients with THA enabling imaging with clinically feasible acquisition and reconstruction times. (Source: Investigative Radiology)
Source: Investigative Radiology - December 7, 2018 Category: Radiology Tags: Original Articles Source Type: research

Accurate Therapeutic Response Assessment of Pancreatic Ductal Adenocarcinoma Using Quantitative Dynamic Contrast-Enhanced Magnetic Resonance Imaging With a Point-of-Care Perfusion Phantom: A Pilot Study
Objectives The aim of this study was to test the feasibility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) with concurrent perfusion phantom for monitoring therapeutic response in patients with pancreatic ductal adenocarcinoma (PDAC). Materials and Methods A prospective pilot study was conducted with 8 patients (7 men and 1 woman) aged 46 to 78 years (mean age, 66 years). Participants had either locally advanced (n = 7) or metastatic (n = 1) PDAC, and had 2 DCE-MRI examinations: one before and one 8 ± 1 weeks after starting first-line chemotherapy. A small triplicate perfusion phantom was im...
Source: Investigative Radiology - December 7, 2018 Category: Radiology Tags: Original Articles Source Type: research

Deep Learning in Diagnosis of Maxillary Sinusitis Using Conventional Radiography
Conclusions The deep learning algorithm could diagnose maxillary sinusitis on Waters’ view radiograph with superior AUC and comparable sensitivity and specificity to those of radiologists. (Source: Investigative Radiology)
Source: Investigative Radiology - December 7, 2018 Category: Radiology Tags: Original Articles Source Type: research

Interscanner and Intrascanner Comparison of Virtual Unenhanced Attenuation Values Derived From Twin Beam Dual-Energy and Dual-Source, Dual-Energy Computed Tomography
Conclusions Dual-energy techniques vary in reproducibility of VUE attenuation values. In the current study, tbDECT demonstrated higher variation in VUE HU measurements in comparison to a dsDECT. Virtual unenhanced HU measurements cannot be reliably compared on follow-up CT, if these 2 different dual-energy CT platforms are used. (Source: Investigative Radiology)
Source: Investigative Radiology - December 7, 2018 Category: Radiology Tags: Original Articles Source Type: research

Spatiotemporal Pattern of Gadodiamide-Related T1 Hyperintensity Increase Within the Deep Brain Nuclei
Objectives The purpose of the study was to systematically evaluate the precise spatial and temporal pattern of gadolinium-related changes in T1-weighted signal intensity on unenhanced magnetic resonance (MR) images, occurring in the deep brain nuclei of adult patients exposed to at least 10 consecutive doses of gadodiamide. Materials and Methods In this monocentric retrospective longitudinal study, we analyzed the brain MR images of 30 patients (12 women, 18 men; mean age, 43 ± 11.6 years) acquired between December 1998 and March 2008. We drew the regions of interest in the dentate nucleus, globus pallidus, put...
Source: Investigative Radiology - November 7, 2018 Category: Radiology Tags: Original Articles Source Type: research

Accelerated Internal Auditory Canal Screening Magnetic Resonance Imaging Protocol With Compressed Sensing 3-Dimensional T2-Weighted Sequence
Background and Purpose High-resolution T2-weighted sequences are frequently used in magnetic resonance imaging (MRI) studies to assess the cerebellopontine angle and internal auditory canal (IAC) in sensorineural hearing loss patients but have low yield and lengthened examinations. Because image content in the Wavelet domain is sparse, compressed sensing (CS) that uses incoherent undersampling of k-space and iterative reconstruction can accelerate MRI acquisitions. We hypothesized that an accelerated CS T2 Sampling Perfection with Application optimized Contrasts using different flip angle Evolution (SPACE) sequence would...
Source: Investigative Radiology - November 7, 2018 Category: Radiology Tags: Original Articles Source Type: research

Quantitative Apparent Diffusion Coefficient Derived From Diffusion-Weighted Imaging Has the Potential to Avoid Unnecessary MRI-Guided Biopsies of mpMRI-Detected PI-RADS 4 and 5 Lesions
Conclusions Quantitative ADC measurement in multiparametric MRI–detected PI-RADS 4 and 5 lesions has the potential to avoid unnecessary MRI-guided biopsies in up to 33%. (Source: Investigative Radiology)
Source: Investigative Radiology - November 7, 2018 Category: Radiology Tags: Original Articles Source Type: research

Metal Artifact Reduction Computed Tomography of Arthroplasty Implants: Effects of Combined Modeled Iterative Reconstruction and Dual-Energy Virtual Monoenergetic Extrapolation at Higher Photon Energies
Objective The aim of this study was to compare the effects of combined virtual monoenergetic extrapolation (VME) of dual-energy computed tomography data and iterative metal artifact reduction (iMAR) at higher photon energies on low- and high-density metal artifacts and overall image quality of the ankle arthroplasty implants with iMAR, weighted filtered back projection (WFBP), and WFBP-based VME. Materials and Methods Total ankle arthroplasty implants in 6 human cadaver ankles served as surrogates for arthroplasty implants. All specimens underwent computed tomography with a 2 × 192-slice dual-source computed tom...
Source: Investigative Radiology - November 7, 2018 Category: Radiology Tags: Technical Note Source Type: research

Preoperative Evaluation of Pancreatic Fibrosis and Lipomatosis: Correlation of Magnetic Resonance Findings With Histology Using Magnetization Transfer Imaging and Multigradient Echo Magnetic Resonance Imaging
Objectives The purpose of this study was to evaluate the diagnostic performance of magnetization transfer (MT) imaging and multigradient echo magnetic resonance imaging (MRI) to quantify pancreatic fibrosis and lipomatosis in patients before pancreatoduodenectomy for postoperative risk stratification with histopathology as the reference standard. Materials and Methods Twenty-four patients (age, 68 ± 8 years, 16 males) prospectively underwent quantitative MT imaging using a 2-dimensional gradient echo sequence with and without MT prepulse and multigradient echo imaging on a 3 T MRI 1 day before pancreatoduodenec...
Source: Investigative Radiology - November 7, 2018 Category: Radiology Tags: Original Articles Source Type: research

Initial Assessment of a Prototype 3D Cone-Beam Computed Tomography System for Imaging of the Lumbar Spine, Evaluating Human Cadaveric Specimens in the Upright Position
Objectives The aims of this study were to assess feasibility, image quality, and radiation dose and to estimate the optimal dose protocol for the lumbar spine of cadaveric specimens with different body mass indices (BMIs) in the upright position using a prototype 3-dimensional cone-beam computed tomography (CT) software implemented on a robotic x-ray system and compare with CT. Materials and Methods The lumbar spine of 5 formalin-fixed human cadaveric specimens (BMI, 22–35 kg/m2) was prospectively assessed in the upright position using prototype software for 3-dimensional tomography implemented on a robotic x-ra...
Source: Investigative Radiology - November 7, 2018 Category: Radiology Tags: Original Articles Source Type: research

Feasibility of Diffusion Tensor and Morphologic Imaging of Peripheral Nerves at Ultra-High Field Strength
Objectives The aim of this study was to describe the development of morphologic and diffusion tensor imaging sequences of peripheral nerves at 7 T, using carpal tunnel syndrome (CTS) as a model system of focal nerve injury. Materials and Methods Morphologic images were acquired at 7 T using a balanced steady-state free precession sequence. Diffusion tensor imaging was performed using single-shot echo-planar imaging and readout-segmented echo-planar imaging sequences. Different acquisition and postprocessing methods were compared to describe the optimal analysis pipeline. Magnetic resonance imaging parameters including...
Source: Investigative Radiology - November 7, 2018 Category: Radiology Tags: Technical Note Source Type: research

Three-Dimensional High-Resolution Black-Blood Magnetic Resonance Imaging for Detection of Arteritic Anterior Ischemic Optic Neuropathy in Patients With Giant Cell Arteritis
Objectives Arteritic anterior ischemic optic neuropathy (A-AION) caused by inflammatory occlusion of the posterior ciliary arteries is the most common reason for irreversible vision loss in patients with giant cell arteritis. Atypical clinical presentation and negative funduscopy can delay systemic high-dose corticosteroid therapy to prevent impending permanent blindness and involvement of the contralateral eye. The purpose of this study was to assess the diagnostic accuracy of 3-dimensional (3D) high-resolution T1-weighted black-blood magnetic resonance imaging (T1-BB-MRI) for the detection of posterior ciliary artery ...
Source: Investigative Radiology - October 11, 2018 Category: Radiology Tags: Original Articles Source Type: research

Fully Automated 10-Minute 3D CAIPIRINHA SPACE TSE MRI of the Knee in Adults: A Multicenter, Multireader, Multifield-Strength Validation Study
Objectives The aim of this study was to test the hypothesis that magnetic resonance imaging (MRI) of the knee with 10-minute 3-dimensional (3D) controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) sampling perfection with application optimized contrast using different flip angle evolutions (SPACE) turbo spin echo (TSE) protocols can replace 20-minute 2-dimensional (2D) TSE standard-of-reference protocols for the diagnosis of internal derangement. Materials and Methods After internal review board approval and prospective informed consent, 100 symptomatic subjects underwent MRI of the knee...
Source: Investigative Radiology - October 11, 2018 Category: Radiology Tags: Original Articles Source Type: research

Acceleration of Magnetic Resonance Cholangiopancreatography Using Compressed Sensing at 1.5 and 3 T: A Clinical Feasibility Study
Objectives Magnetic resonance cholangiopancreatography (MRCP) is an established technique in routine magnetic resonance examination. By applying the compressed sensing (CS) acceleration technique to conventional MRCP sequences, scan time can be markedly reduced. With promising results at 3 T, there is a necessity to evaluate the performance at 1.5 T due to wide scanner availabilities. Aim of this study is to test the feasibility of accelerated 3-dimensional (3D) MRCP with extended sampling perfection with application-optimized contrasts using different flip angle evolution (SPACE) using CS in navigator triggering and in ...
Source: Investigative Radiology - October 11, 2018 Category: Radiology Tags: Original Articles Source Type: research

Quantification of Cisplatin Using a Modified 3-Material Decomposition Algorithm at Third-Generation Dual-Source Dual-Energy Computed Tomography: An Experimental Study
Objective The aim of this study was to assess the ability of third-generation dual-source dual-energy computed tomography to quantify cisplatin concentration using a 3-material decomposition algorithm in an experimental phantom. Materials and Methods Fifteen agarose-based phantoms containing various concentrations of iodine (0, 1.0, 2.0 mg I/mL) and cisplatin (0, 0.5, 1.0, 2.0, 3.0 mg Pt/mL) were scanned using third-generation dual-source dual-energy computed tomography at 80 kV and 150 kV with tin prefiltration. A cisplatin map was generated using the cisplatin-specific 3-material decomposition algorithm to different...
Source: Investigative Radiology - October 11, 2018 Category: Radiology Tags: Original Articles Source Type: research

Magnetic Resonance Imaging–Based Grading of Cartilaginous Bone Tumors: Added Value of Quantitative Texture Analysis
Conclusions Texture analysis improves diagnostic accuracy for differentiation of benign and malignant as well as for benign and low-grade cartilaginous lesions when compared with morphologic MRI analysis. (Source: Investigative Radiology)
Source: Investigative Radiology - October 11, 2018 Category: Radiology Tags: Original Articles Source Type: research

150-μm Spatial Resolution Using Photon-Counting Detector Computed Tomography Technology: Technical Performance and First Patient Images
Conclusions Phantom studies demonstrated superior resolution and noise properties for the Sharp and UHR modes relative to the standard Macro mode and patient images demonstrated the potential benefit of these scan modes for clinical practice. (Source: Investigative Radiology)
Source: Investigative Radiology - October 11, 2018 Category: Radiology Tags: Original Articles Source Type: research

Clinical Evaluation of a Multiparametric Deep Learning Model for Glioblastoma Segmentation Using Heterogeneous Magnetic Resonance Imaging Data From Clinical Routine
Conclusions The proposed approach for automatic segmentation of GB proved to be robust on routine clinical data and showed on all tumor compartments a high automatic detection rate and a high accuracy, comparable to interrater variability. Further work on improvements of the segmentation accuracy for the necrosis compartments should be guided by the evaluation of the clinical relevance. Therefore, we propose this approach as a suitable building block for automatic tumor segmentation to support radiologists or neurosurgeons in the preoperative reading of GB MRI images and characterization of primary GB. (Source: Investigative Radiology)
Source: Investigative Radiology - October 11, 2018 Category: Radiology Tags: Original Articles Source Type: research

Precise and Automatic Patient Positioning in Computed Tomography: Avatar Modeling of the Patient Surface Using a 3-Dimensional Camera
This study included data of 120 patients undergoing clinically indicated chest (n = 68) and abdomen (n = 52) CT. Fifty-two of the patients were scanned with CT using a table height manually selected by technologists; 68 patients were automatically positioned with the 3D camera, which is based on patient-specific body surface and contour detection. The ground truth table height (TGT) was defined as the table height that aligns the axial center of the patient’s body region in the CT scanner isocenter. Off-centering was defined as the difference between the ground truth table height (TGT) and the actual table position u...
Source: Investigative Radiology - October 11, 2018 Category: Radiology Tags: Original Articles Source Type: research

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