The Effect of Gadolinium-Based Contrast Agents on Longitudinal Changes of Magnetic Resonance Imaging Signal Intensities and Relaxation Times in the Aging Rat Brain
Objectives
The aim of the study was to investigate the possible influence of changes in the brain caused by age on relaxometric and relaxation time–weighted magnetic resonance imaging (MRI) parameters in the deep cerebellar nuclei (DCN) and the globus pallidus (GP) of Gd-exposed and control rats over the course of 1 year.
Materials and Methods
Twenty-five Wistar-Han rats were equally subdivided into 5 groups and initially received 8 injections on 4 consecutive days per week of either 3.6 mL/kg body weight saline (group I–III) or 1.8 mmol Gd/kg body weight gadobutrol (group IV) or gadodiamide (group V). T1- a...
Source: Investigative Radiology - June 20, 2022 Category: Radiology Tags: Original Articles Source Type: research
Characterizing Scatter Correction Software of 5 Mobile Radiography Units: An Anthropomorphic Phantom Study
Conclusions
We have proven in a proof of concept that the originally developed IQAA can be used to characterize different series of images of different manufacturers. Based on the physical quantities, SC SW increases the contrast, detail, sharpness, and noise. The experimental results in this study assume a patient dose reduction could be possible when SC SW is applied. (Source: Investigative Radiology)
Source: Investigative Radiology - June 20, 2022 Category: Radiology Tags: Original Articles Source Type: research
Benchmarking Feature Selection Methods in Radiomics
Conclusion
Our results indicated that simpler methods are more stable than complex ones and do not perform worse in terms of area under the receiver operating characteristic curve. Analysis of variance, least absolute shrinkage and selection operator, and minimum redundancy, maximum relevance ensemble appear to be good choices for radiomic studies in terms of predictive performance, as they outperformed most other feature selection methods. (Source: Investigative Radiology)
Source: Investigative Radiology - June 20, 2022 Category: Radiology Tags: Original Articles Source Type: research
A Deep Learning Approach to Predicting Disease Progression in Multiple Sclerosis Using Magnetic Resonance Imaging
Conclusions
We developed a robust and accurate model for predicting clinical and cognitive worsening of MS patients after 2 years, based on conventional T2-weighted and T1-weighted brain MRI scans obtained at baseline. This algorithm may be valuable for supporting physicians in their clinical practice for the earlier identification of MS patients at risk of disease worsening. (Source: Investigative Radiology)
Source: Investigative Radiology - June 20, 2022 Category: Radiology Tags: Original Articles Source Type: research
Comparison of T2 Quantification Strategies in the Abdominal-Pelvic Region for Clinical Use
Conclusions
To perform T2 measurement in the abdominal-pelvic region, one should favor a technique with acceptable acquisition time for clinical use, with proper respiratory motion management, with good repeatability, reproducibility, and precision. In this study, the techniques relying respectively on SE-EPI, radial TSE, and GRAPPATINI appeared as good candidates. (Source: Investigative Radiology)
Source: Investigative Radiology - May 8, 2022 Category: Radiology Tags: Original Articles Source Type: research
Extracellular Volume Quantification With Cardiac Late Enhancement Scanning Using Dual-Source Photon-Counting Detector CT
Objectives
The aim of this study was to evaluate the feasibility and accuracy of cardiac late enhancement (LE) scanning for extracellular volume (ECV) quantification with dual-source photon-counting detector computed tomography (PCD-CT).
Materials and Methods
In this institutional review board–approved study, 30 patients (mean age, 79 years; 12 women; mean body mass index, 28 kg/m2) with severe aortic stenosis undergoing PCD-CT as part of their preprocedural workup for transcatheter aortic valve replacement were included. The scan protocol consisted of a nonenhanced calcium-scoring scan, coronary CT angiograph...
Source: Investigative Radiology - May 8, 2022 Category: Radiology Tags: Original Articles Source Type: research
Photon-Counting Detector CT-Based Vascular Calcium Removal Algorithm: Assessment Using a Cardiac Motion Phantom
Objectives
The diagnostic performance of coronary computed tomography angiography is known to be negatively affected by the presence of severely calcified plaques in the coronary arteries. In this article, the performance of a novel image reconstruction algorithm (PureLumen) based on spectral CT data of a first-generation dual-source photon-counting detector computed tomography (PCD-CT) system was assessed in a phantom study. PureLumen tries to remove only the calcified contributions from the image while leaving the rest unmodified.
Materials and Methods
The study uses 2 iodine contrast filled vessel phantoms (d...
Source: Investigative Radiology - May 8, 2022 Category: Radiology Tags: Original Articles Source Type: research
Basic and Advanced Metal-Artifact Reduction Techniques at Ultra-High Field 7-T Magnetic Resonance Imaging—Phantom Study Investigating Feasibility and Efficacy
Objectives
The aim of this study was to demonstrate the feasibility and efficacy of basic (increased receive bandwidth) and advanced (view-angle tilting [VAT] and slice-encoding for metal artifact correction [SEMAC]) techniques for metal-artifact reduction in ultra-high field 7-T magnetic resonance imaging (MRI).
Materials and Methods
In this experimental study, we performed 7-T MRI of titanium alloy phantom models composed of a spinal pedicle screw (phantom 1) and an intervertebral cage (phantom 2) centered in a rectangular LEGO frame, embedded in deionized-water-gadolinium (0.1 mmol/L) solution. The following ...
Source: Investigative Radiology - May 8, 2022 Category: Radiology Tags: Original Articles Source Type: research
Impact of Deep Learning Reconstruction Combined With a Sharpening Filter on Single-Shot Fast Spin-Echo T2-Weighted Magnetic Resonance Imaging of the Uterus
This study aimed to evaluate the effects of deep learning (DL) reconstruction and a postprocessing sharpening filter on the image quality of single-shot fast spin-echo (SSFSE) T2-weighted imaging (T2WI) of the uterus.
Materials and Methods
Fifty consecutive patients who underwent pelvic magnetic resonance imaging were included. Parasagittal T2WI with a slice thickness of 4 mm was obtained with the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) and SSFSE sequences (mean scan time, 204 and 22 seconds, respectively). The following 3 types of SSFSE images were reconstructed, and...
Source: Investigative Radiology - May 8, 2022 Category: Radiology Tags: Original Articles Source Type: research
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
