Clinical High-Resolution 3D-MR Spectroscopic Imaging of the Human Brain at 7 T
Objectives Available clinical magnetic resonance spectroscopic imaging (MRSI) sequences are hampered by long scan times, low spatial resolution, strong field inhomogeneities, limited volume coverage, and low signal-to-noise ratio. High-resolution, whole-brain mapping of more metabolites than just N-acetylaspartate, choline, and creatine within clinically attractive scan times is urgently needed for clinical applications. The aim is therefore to develop a free induction decay (FID) MRSI sequence with rapid concentric ring trajectory (CRT) encoding for 7 T and demonstrate its clinical feasibility for mapping the whole cere...
Source: Investigative Radiology - March 12, 2020 Category: Radiology Tags: Technical Notes Source Type: research

Simultaneous Multislice Diffusion-Weighted Imaging of the Kidneys at 3 T
Purpose The aim of this study was to compare respiratory-triggered diffusion-weighted imaging with simultaneous-multislice acceleration (SMS-RT-DWI) to a standard free-breathing echoplanar DWI (s-DWI) for 3 T renal imaging with respect to image quality and artifacts. Materials and Methods A total of 40 patients who had undergone renal magnetic resonance imaging were included in this retrospective analysis of a prospectively planned cohort study. All examinations were performed on a 3 T whole-body magnetic resonance system. Both s-DWI and SMS-RT-DWI were obtained and images were independently reviewed by 2 radiologists...
Source: Investigative Radiology - March 12, 2020 Category: Radiology Tags: Original Articles Source Type: research

A Universal Protocol for Abdominal CT Examinations Performed on a Photon-Counting Detector CT System: A Feasibility Study
Objective The aims of this study were to investigate the feasibility of using a universal abdominal acquisition protocol on a photon-counting detector computed tomography (PCD-CT) system and to compare its performance to that of single-energy (SE) and dual-energy (DE) CT using energy-integrating detectors (EIDs). Methods Iodine inserts of various concentrations and sizes were embedded into different sizes of adult abdominal phantoms. Phantoms were scanned on a research PCD-CT and a clinical EID-CT with SE and DE modes. Virtual monoenergetic images (VMIs) were generated from PCD-CT and DE mode of EID-CT. For each image...
Source: Investigative Radiology - March 12, 2020 Category: Radiology Tags: Original Articles Source Type: research

Magnetic Resonance Kidney Parenchyma-T2 as a Novel Imaging Biomarker for Autosomal Dominant Polycystic Kidney Disease
Objective Autosomal dominant polycystic kidney disease (ADPKD) is a chronic progressive disorder with a significant disease burden leading to end-stage renal disease in more than 75% of the affected individuals. Although prediction of disease progression is highly important, all currently available biomarkers—including height-adjusted total kidney volume (htTKV)—have important drawbacks in the everyday clinical setting. Thus, the purpose of this study was to evaluate T2 mapping as a source of easily obtainable and accurate biomarkers, which are needed for improved patient counseling and selection of targeted treatmen...
Source: Investigative Radiology - March 12, 2020 Category: Radiology Tags: Original Articles Source Type: research

Molecular Magnetic Resonance Imaging of Fibrin Deposition in the Liver as an Indicator of Tissue Injury and Inflammation
Rationale and Objectives Liver inflammation is associated with nonalcoholic steatohepatitis and other pathologies, but noninvasive methods to assess liver inflammation are limited. Inflammation causes endothelial disruption and leakage of plasma proteins into the interstitial space and can result in extravascular coagulation with fibrin deposition. Here we assess the feasibility of using the established fibrin-specific magnetic resonance probe EP-2104R for the noninvasive imaging of fibrin as a marker of liver inflammation. Methods Weekly 100 mg/kg diethylnitrosamine (DEN) dosing was used to generate liver fibrosis in...
Source: Investigative Radiology - March 12, 2020 Category: Radiology Tags: Original Articles Source Type: research

Identification of Normal Pressure Hydrocephalus by Disease-Specific Patterns of Brain Stiffness and Damping Ratio
Objectives The aim of this study was to perform a whole-brain analysis of alterations in brain mechanical properties due to normal pressure hydrocephalus (NPH). Materials and Methods Magnetic resonance elastography (MRE) examinations were performed on 85 participants, including 44 cognitively unimpaired controls, 33 with NPH, and 8 who were amyloid-positive with Alzheimer clinical syndrome. A custom neural network inversion was used to estimate stiffness and damping ratio from patches of displacement data, accounting for edges by training the network to estimate the mechanical properties in the presence of missing dat...
Source: Investigative Radiology - March 12, 2020 Category: Radiology Tags: Original Article Source Type: research

Repeatability and Agreement of Shear Wave Speed Measurements in Phantoms and Human Livers Across 6 Ultrasound 2-Dimensional Shear Wave Elastography Systems
Conclusions There is good to excellent intersystem agreement of measured SWS in elastic phantoms and in vivo livers across 6 ultrasound 2D SWE systems. Test-retest repeatability was excellent for all systems. (Source: Investigative Radiology)
Source: Investigative Radiology - March 12, 2020 Category: Radiology Tags: Original Articles Source Type: research

Ultrafast Brain Magnetic Resonance Imaging in Acute Neurological Emergencies: Diagnostic Accuracy and Impact on Patient Management
Conclusions Ultrafast-MRI enables time-optimized diagnostic workup in acute neurological emergencies at high sensitivity and specificity compared with a standard-length protocol, with direct impact on patient management. Ultrafast MRI protocols are a powerful tool in the emergency setting and may be implemented on various scanner types based on the optimization of individual acquisition parameters. (Source: Investigative Radiology)
Source: Investigative Radiology - February 11, 2020 Category: Radiology Tags: Original Articles Source Type: research

Quantification of Aortic Stiffness by Ultrasound Time-Harmonic Elastography: The Effect of Intravascular Pressure on Elasticity Measures in a Porcine Model
Conclusions In our model, aortic stiffness measurements by ultrasound time-harmonic elastography are influenced to a small extent by mean arterial pressure in a range of 1.89% to 8.60%. These findings emphasize the potential of ultrasound THE for measuring the intrinsic stiffness of the aortic wall in clinical routine. (Source: Investigative Radiology)
Source: Investigative Radiology - February 11, 2020 Category: Radiology Tags: Original Articles Source Type: research

Dual Plasma Sampling Method to Determine the Hepatic and Renal Clearance of the 2 Diastereoisomers of Gd-EOB-DTPA
Objectives The aim of this study was to develop a method to determine hepatic and renal clearance of the 2 diastereoisomers (Gd-A, Gd-B) of Gd-EOB-DTPA separately. Materials and Methods Between July 2017 and February 2018, 41 patients with hepatic disease were prospectively included. For each patient, 1 mL of iopromide (to determine glomerular filtration rate [GFR]) was coadministered with Gd-EOB-DTPA (Gd-A and Gd-B; 65:35 wt/wt). The plasma clearances of Gd-A (PCL-GdA) and Gd-B (PCL-GdB) as well as the iopromide (GFR) were generated by using dual plasma sampling method. Meanwhile, the patient's urine was collected fo...
Source: Investigative Radiology - February 11, 2020 Category: Radiology Tags: Original Articles Source Type: research

Medication-Related Osteonecrosis of the Jaw—Comparison of Bone Imaging Using Ultrashort Echo-Time Magnetic Resonance Imaging and Cone-Beam Computed Tomography
Objective The aim of this study was to compare bone imaging between ultrashort echo-time (UTE) magnetic resonance (MR) imaging and cone-beam computed tomography (CBCT) as the reference standard in patients with medication-related osteonecrosis of the jaw (MRONJ). Materials and Methods A 1-year retrospective, blinded, and randomized qualitative analysis of UTE MR images and CBCT from 19 patients with clinically diagnosed MRONJ was performed by 2 independent radiologists. Medication-related osteonecrosis of the jaw imaging hallmarks such as osteolysis, periosteal thickening, and medullary osteosclerosis were rated visua...
Source: Investigative Radiology - February 11, 2020 Category: Radiology Tags: Original Articles Source Type: research

Respiratory Motion Detection and Correction for MR Using the Pilot Tone: Applications for MR and Simultaneous PET/MR Examinations
Conclusions The presented method provides reliable respiratory motion tracking during arbitrary imaging sequences throughout a full PET/MR study. All results can directly be transferred to MR-only applications as well. (Source: Investigative Radiology)
Source: Investigative Radiology - February 11, 2020 Category: Radiology Tags: Original Articles Source Type: research

Safety Analysis of Iobitridol as a Nonionic Contrast Medium: A Postmarketing Multicenter Surveillance Study With 94,960 Patients Almost 20 Years After Introduction
Objectives Our study sought to reevaluate the safety and diagnostic efficacy of iobitridol as a nonionic contrast medium after almost 20 years of use. Materials and methods This noninterventional postmarketing surveillance noncontrolled, multicenter (168 centers in Germany) study enrolled 94,960 patients receiving intravenous or intra-arterial iobitridol. The majority of the adjusted population (n = 92,550, 98.2%) underwent either computed tomography examination (n = 46,502, 49.3%) or intravenous urography (n = 46,048, 48.8%). A standardized questionnaire was used to ascertain patient's information, known risk factors...
Source: Investigative Radiology - February 11, 2020 Category: Radiology Tags: Original Articles Source Type: research

Long-Term Evaluation of Gadolinium Retention in Rat Brain After Single Injection of a Clinically Relevant Dose of Gadolinium-Based Contrast Agents
Purpose The aim of this study was to investigate the presence and chemical forms of residual gadolinium (Gd) in rat brain after a single dose of Gd-based contrast agent. Methods Four groups of healthy rats (2 sacrifice time-points, n = 10/group, 80 rats in total) were randomized to receive a single intravenous injection of 1 of the 3 Gd-based contrast agents (GBCAs) (gadoterate meglumine, gadobenate dimeglumine, or gadodiamide) or the same volume of 0.9% saline solution. The injected concentration was 0.6 mmol/kg, corresponding to a concentration of 0.1 mmol/kg in humans after body surface normalization between rats a...
Source: Investigative Radiology - February 11, 2020 Category: Radiology Tags: Original Articles Source Type: research

Dose Finding Study of Gadopiclenol, a New Macrocyclic Contrast Agent, in MRI of Central Nervous System
Conclusions Between the doses of 0.025 and 0.2 mmol/kg of gadopiclenol, the increase in CNR is linear. Compared with gadobenate dimeglumine at 0.1 mmol/kg, the doses of 0.05 and 0.1 mmol/kg of gadopiclenol gave similar or significantly greater contrast enhancement, respectively, and thus both doses can be considered for future phase III studies. (Source: Investigative Radiology)
Source: Investigative Radiology - February 11, 2020 Category: Radiology Tags: Original Articles Source Type: research