The Compressed Sensing MP2RAGE as a Surrogate to the MPRAGE for Neuroimaging at 3 T
Objectives The magnetization-prepared 2 rapid acquisition gradient echo (MP2RAGE) sequence provides quantitative T1 maps in addition to high-contrast morphological images. Advanced acceleration techniques such as compressed sensing (CS) allow its acquisition time to be compatible with clinical applications. To consider its routine use in future neuroimaging protocols, the repeatability of the segmented brain structures was evaluated and compared with the standard morphological sequence (magnetization-prepared rapid gradient echo [MPRAGE]). The repeatability of the T1 measurements was also assessed. Materials and Met...
Source: Investigative Radiology - May 8, 2022 Category: Radiology Tags: Original Articles Source Type: research

Impact of Contrast Enhancement and Virtual Monoenergetic Image Energy Levels on Emphysema Quantification: Experience With Photon-Counting Detector Computed Tomography
Purpose The aim of this study was to evaluate the impact of contrast enhancement and different virtual monoenergetic image energies on automatized emphysema quantification with photon-counting detector computed tomography (PCD-CT). Material and Methods Sixty patients who underwent contrast-enhanced chest CT on a first-generation, clinical dual-source PCD-CT were retrospectively included. Scans were performed in the multienergy (QuantumPlus) mode at 120 kV with weight-adjusted intravenous contrast agent. Virtual noncontrast (VNC) images as well as virtual monoenergetic images (VMIs) from 40 to 80 keV obtained in ...
Source: Investigative Radiology - May 8, 2022 Category: Radiology Tags: Original Articles Source Type: research

Individualized Scan Protocols in Abdominal Computed Tomography: Radiation Versus Contrast Media Dose Optimization
Background In contrast-enhanced abdominal computed tomography (CT), radiation and contrast media (CM) injection protocols are closely linked to each other, and therefore a combination is the basis for achieving optimal image quality. However, most studies focus on optimizing one or the other parameter separately. Purpose Reducing radiation dose may be most important for a young patient or a population in need of repetitive scanning, whereas CM reduction might be key in a population with insufficient renal function. The recently introduced technical solution, in the form of an automated tube voltage selection (AT...
Source: Investigative Radiology - May 8, 2022 Category: Radiology Tags: Original Articles Source Type: research

Estimation of Contrast Agent Concentration in DCE-MRI Using 2 Flip Angles
Conclusions This study substantiates the feasibility of using the 2-FA approach during DCE-MRI scan to estimate [Gd] in the plasma without using an extra scan to perform precontrast T1 measurements. (Source: Investigative Radiology)
Source: Investigative Radiology - April 9, 2022 Category: Radiology Tags: Original Articles Source Type: research

Reliable Assessment of Swine Renal Fibrosis Using Quantitative Magnetization Transfer Imaging
Objectives Quantitative magnetization transfer (qMT) is useful for measurement of murine renal fibrosis at high and ultrahigh field strengths. However, its utility at clinical field strengths and in human-like kidneys remains unknown. We tested the hypothesis that qMT would successfully detect fibrosis in swine kidneys with unilateral renal artery stenosis (RAS) at 3.0 T. Methods The qMT protocol is composed of MT scans with variable flip angles and offset frequencies, and of B0, B1, and T1 mapping. Pigs were scanned 10 weeks after RAS or control. A 2-pool model was used to fit the bound pool fraction f of the r...
Source: Investigative Radiology - April 9, 2022 Category: Radiology Tags: Original Articles Source Type: research

Deep Learning Algorithm for Fully Automated Detection of Small (≤4 cm) Renal Cell Carcinoma in Contrast-Enhanced Computed Tomography Using a Multicenter Database
Conclusions The proposed deep learning–based algorithm achieved high accuracy, sensitivity, specificity, and AUC for the detection of small RCCs with both internal and external validations, suggesting that this algorithm could contribute to the early detection of small RCCs. (Source: Investigative Radiology)
Source: Investigative Radiology - April 9, 2022 Category: Radiology Tags: Original Articles Source Type: research

Risk of Hypersensitivity Reactions to Iopromide in Children and Elderly: An Analysis of 132,850 Patients From 4 Observational Studies and Pharmacovigilance Covering >288 Million Administrations
Purpose The aim of this study was to analyze the risk of hypersensitivity reactions (HSRs) to iopromide in children and elderly patients in comparison to adults. Materials and Methods Four observational studies were pooled and analyzed (analysis I). In addition, spontaneous reports from 1985 to 2020 from the pharmacovigilance database were evaluated (analysis II). All patients received iopromide for angiographic procedures or contrast-enhanced computed tomography in various indications. In analysis I, a nested case-control analysis, including a multivariable logistic regression model, based on pooled observation...
Source: Investigative Radiology - April 9, 2022 Category: Radiology Tags: Original Articles Source Type: research

Deep Learning-Based Image Conversion Improves the Reproducibility of Computed Tomography Radiomics Features: A Phantom Study
Conclusions Our study demonstrated that a deep learning model for image conversion can improve the reproducibility of radiomics features across various CT protocols, reconstruction kernels, and CT scanners. (Source: Investigative Radiology)
Source: Investigative Radiology - April 9, 2022 Category: Radiology Tags: Original Articles Source Type: research

Dual-Echo Turbo Spin Echo and 12-Echo Multi Spin Echo Sequences as Equivalent Techniques for Obtaining T2-Relaxometry Data: Application in Symptomatic and Asymptomatic Hereditary Transthyretin Amyloidosis as a Surrogate Disease
Objectives Multi spin echo (MSE) sequences are often used for obtaining T2-relaxometry data as they provide defined echo times (TEs). Due to their time-consuming acquisition, they are frequently replaced by turbo spin echo (TSE) sequences that in turn bear the risk of systematic errors when analyzing small structures or lesions. With this study, we aim to test whether T2-relaxometry data derived from either dual-echo TSE or 12-echo MSE sequences are equivalent for quantifying peripheral nerve lesions. Hereditary transthyretin (ATTRv) amyloidosis was chosen as a surrogate disease, as it allows the inclusion of both asym...
Source: Investigative Radiology - April 9, 2022 Category: Radiology Tags: Original Articles Source Type: research

Severity of Flare Reactions in Diethylenetriamine Pentaacetate Chelations: Report on Different Immune Dampening Strategies in Clinical Practice
Conclusion Based on early clinical experience, EHMR seems to manage flare reactions in DTPA chelation well. This strategy may represent the first standard therapy in patients with GDD. (Source: Investigative Radiology)
Source: Investigative Radiology - April 9, 2022 Category: Radiology Tags: Original Articles Source Type: research

Comprehensive Speciation Analysis of Residual Gadolinium in Deep Cerebellar Nuclei in Rats Repeatedly Administered With Gadoterate Meglumine or Gadodiamide
Conclusion A dedicated analytical workflow produced original data on the speciation of Gd in DCN of rats repeatedly injected with GBCAs. The addition, in comparison with previous studies of Gd speciation in brain, of SP element detection and imaging techniques allowed a comprehensive speciation analysis approach. Whereas for gadoterate the main fraction of retained Gd was present as intact GBCA form in the soluble fractions, for linear gadodiamide, less than 10% of Gd could be solubilized and characterized using size-exclusion chromatography coupled to ICP-MS. The main Gd species detected in the soluble fractions were ...
Source: Investigative Radiology - April 9, 2022 Category: Radiology Tags: Original Articles Source Type: research

Repeatability and Reproducibility of ADC Measurements and MRI Signal Intensity Measurements of Bone Marrow in Monoclonal Plasma Cell Disorders: A Prospective Bi-institutional Multiscanner, Multiprotocol Study
Conclusions The MRI scanners with identical field strength and harmonized MRI protocols can provide relatively stable quantitative measurements of BM ADC and SI. Deviations in MRI field strength and MRI protocol should be avoided when applying ADC cutoff values, which were established at other scanners or when performing multicentric imaging trials. (Source: Investigative Radiology)
Source: Investigative Radiology - March 17, 2022 Category: Radiology Tags: Original Articles Source Type: research

Fast Quantitative Low-Field Magnetic Resonance Imaging With OPTIMUM—Optimized Magnetic Resonance Fingerprinting Using a Stationary Steady-State Cartesian Approach and Accelerated Acquisition Schedules
Conclusion We show that low-field MRI can benefit from innovative multiparametric approaches to gain speed and become realistic in clinical environments. For the first time, we report simultaneous, multiparametric imaging (6 quantitative maps) in 3 dimensions, in vivo in the human hand and wrist, obtained in just 8.5 minutes. It is sometimes overlooked that low magnetic fields provide higher dispersion of nuclear spin relaxation rates. Rapid quantification such as offered by OPTIMUM could be an enabling technology to explore new metrics and contrasts in point-of-care MRI diagnosis, making it an important step toward br...
Source: Investigative Radiology - March 17, 2022 Category: Radiology Tags: Original Articles Source Type: research

Association of Cerebral Blood Flow and Brain Tissue Relaxation Time With Neurodevelopmental Outcomes of Preterm Neonates: Multidelay Arterial Spin Labeling and Synthetic MRI Study
Conclusions Higher CBF values and lower T1 relaxation times in frontal white matter were associated with poorer cognitive outcomes. As quantitative neuroimaging markers, CBF and relaxation times may help predict neurodevelopmental outcomes in preterm neonates. (Source: Investigative Radiology)
Source: Investigative Radiology - March 17, 2022 Category: Radiology Tags: Original Articles Source Type: research

Repeatability and Reproducibility of Computed Tomography Radiomics for Pulmonary Nodules: A Multicenter Phantom Study
Background Radiomics can yield minable information from medical images, which can facilitate computer-aided diagnosis. However, the lack of repeatability and reproducibility of radiomic features (RFs) may hinder their generalizability in clinical applications. Objectives The aims of this study were to explore 3 main sources of variability in RFs, investigate their influencing magnitudes and patterns, and identify a subset of robust RFs for further studies. Materials and Methods A chest phantom with nodules was scanned with different computed tomography (CT) scanners repeatedly with varying acquisition and...
Source: Investigative Radiology - March 17, 2022 Category: Radiology Tags: Original Articles Source Type: research