Deep Learning‐Based Automated Abdominal Organ Segmentation in the UK Biobank and German National Cohort Magnetic Resonance Imaging Studies
Conclusion Automated segmentation of abdominal organs is possible with high qualitative and quantitative accuracy on whole-body MR imaging data acquired as part of UKBB and GNC. The results obtained and deep learning models trained in this study can be used as a foundation for automated analysis of thousands of MR data sets of UKBB and GNC and thus contribute to tackling topical and original scientific questions. (Source: Investigative Radiology)
Source: Investigative Radiology - May 11, 2021 Category: Radiology Tags: Original Articles Source Type: research

Extravasation Volume at Computed Tomography Angiography Correlates With Bleeding Rate and Prognosis in Patients With Overt Gastrointestinal Bleeding
The objective of our proof-of-concept study was to improve triage of patients with GIB by correlating extravasation volume of first-pass CTA with bleeding rate and clinical outcomes. Materials and Methods All patients who presented with overt GIB and active extravasation on CTA from January 2014 to July 2019 were reviewed in this retrospective, institutional review board–approved and Health Insurance Portability and Accountability Act–compliant study. Extravasation volume was assessed using 3-dimensional software and correlated with hemostatic therapy (primary endpoint) and with intraprocedural bleeding,...
Source: Investigative Radiology - May 11, 2021 Category: Radiology Tags: Original Articles Source Type: research

The Calcium Versus Hemorrhage Trial: Developing Diagnostic Criteria for Chronic Intracranial Susceptibility Lesions Using Single-Energy Computed Tomography, Dual-Energy Computed Tomography, and Quantitative Susceptibility Mapping
Conclusions We provide the updated criteria for the classification of chronic positive susceptibility brain lesions as hemorrhagic versus calcific for each major clinically available imaging modality. These proposed criteria have greater internal consistency than the current criteria and should likely replace it as gold standard. (Source: Investigative Radiology)
Source: Investigative Radiology - May 11, 2021 Category: Radiology Tags: Original Articles Source Type: research

Acute Chelation Therapy‐Associated Changes in Urine Gadolinium, Self-reported Flare Severity, and Serum Cytokines in Gadolinium Deposition Disease
Conclusions In this preliminary study, 24-hour urine Gd content increased markedly and similarly in GDD and GSC patients after Ca-diethylenetriaminepentaacetic acid CT. Post-CT Flare reaction developed only in GDD patients. The current study is the second finding significantly different serum cytokine levels in GDD patients compared with healthy normal controls. These differences and the difference between GDD and GSC patients' Flare and cytokine responses to CT suggest some inflammatory, immunologic, or other physiological differences in patients with GDD. Further research into the treatment and physiological underpin...
Source: Investigative Radiology - May 11, 2021 Category: Radiology Tags: Original Articles Source Type: research

Empiric Switching of Gadolinium-Based Contrast Agents in Patients With History of Previous Immediate Hypersensitivity Reaction to GBCA: A Prospective Single-Center, Single-Arm Efficacy Trial
Conclusions In this prospective single-arm study, empirically switching GBCA to gadoterate in patients with prior HR to GBCA substantially reduced the expected rate of subsequent HRs in patients with and without the use of corticosteroid premedication. Implications for Patient Care Empirically switching GBCAs, with or without the use of corticosteroid premedication, can substantially reduce the rate of hypersensitivity breakthrough reactions. (Source: Investigative Radiology)
Source: Investigative Radiology - May 11, 2021 Category: Radiology Tags: Original Articles Source Type: research

A Deep Learning System for Synthetic Knee Magnetic Resonance Imaging: Is Artificial Intelligence‐Based Fat-Suppressed Imaging Feasible?
Objectives Materials and Methods This single-center study was approved by the institutional review board. Artificial intelligence‐based FS MRI scans were created from non-FS images using a deep learning system with a modified convolutional neural network–based U-Net that used a training set of 25,920 images and validation set of 16,416 images. Three musculoskeletal radiologists reviewed 88 knee MR studies in 2 sessions, the original (proton density [PD] + FSPD) and the synthetic (PD + AFSMRI). Readers recorded AFSMRI quality (diagnostic/nondiagnostic) and the presence or absence of meniscal, ligament, and t...
Source: Investigative Radiology - May 11, 2021 Category: Radiology Tags: Original Articles Source Type: research

A Deep-Learning Diagnostic Support System for the Detection of COVID-19 Using Chest Radiographs: A Multireader Validation Study
Objectives Materials and Methods Five publicly available databases comprising normal CXR, confirmed COVID-19 pneumonia cases, and other pneumonias were used. After the harmonization of the data, the training set included 7966 normal cases, 5451 with other pneumonia, and 258 CXRs with COVID-19 pneumonia, whereas in the testing data set, each category was represented by 100 cases. Eleven blinded radiologists with various levels of expertise independently read the testing data set. The data were analyzed separately with the newly proposed artificial intelligence–based system and by consultant radiologists and re...
Source: Investigative Radiology - May 11, 2021 Category: Radiology Tags: Original Articles Source Type: research

The Macrocyclic Gadolinium-Based Contrast Agents Gadobutrol and Gadoteridol Show Similar Elimination Kinetics From the Brain After Repeated Intravenous Injections in Rabbits
Objective Materials and Methods Male white New Zealand rabbits (2.4–3.1 kg) in 2 study groups (n = 21 each) received 3 injections of either gadobutrol or gadoteridol at 0.9 mmol Gd/kg within 5 days (total dose, 2.7 mmol Gd/kg). Animals in one control group (n = 9) received 3 injections of saline (1.8 mL/kg). After 2, 6, and 12 weeks, 7 animals from each study group and 3 from the control group were killed and the Gd concentrations in the cerebellum, cerebrum, in blood and in urine were determined by inductively coupled plasma mass spectrometry. The chemical species of excreted Gd in urine were determined by h...
Source: Investigative Radiology - May 11, 2021 Category: Radiology Tags: Original Articles Source Type: research

Steadily Increasing Inversion Time Improves Blood Suppression for Free-Breathing 3D Late Gadolinium Enhancement MRI With Optimized Dark-Blood Contrast
Objectives Materials and Methods Fifty consecutive patients with previous cardiac arrhythmias, scheduled for high-resolution 3D LGE MRI, were prospectively enrolled between October 2017 and February 2020. Free-breathing 3D dark-blood LGE MRI with high isotropic resolution (1.6 × 1.6 × 1.6 mm) was performed using a conventional fixed TI (n = 25) or a dynamic TI (n = 25). The average increase in blood nulling TI per minute was obtained from Look-Locker scans before and after the 3D acquisition in the first fixed TI group. This average increment in TI was used as input to calculate the dynamic increment of...
Source: Investigative Radiology - April 9, 2021 Category: Radiology Tags: Technical Note Source Type: research

Application of a Novel Iterative Denoising and Image Enhancement Technique in T1-Weighted Precontrast and Postcontrast Gradient Echo Imaging of the Abdomen: Improvement of Image Quality and Diagnostic Confidence
Objectives The aim of this study was to investigate the impact of a novel iterative denoising and image enhancement technique in T1-weighted precontrast and postcontrast volume-interpolated breath-hold examination (VIBE) of the abdomen on image quality, noise levels, and diagnostic confidence without change of acquisition parameters. Materials and Methods Fifty patients were included in this retrospective, monocentric, institutional review board–approved study after clinically indicated magnetic resonance imaging of the abdomen including T1-weighted precontrast and postcontrast imaging. After acquisition o...
Source: Investigative Radiology - April 9, 2021 Category: Radiology Tags: Original Articles Source Type: research

Pre-examinations Improve Automated Metastases Detection on Cranial MRI
Objective Materials and Methods Our local ethics committee approved this retrospective monocenter study. First, a dual-time approach was assessed, for which the CNN was provided sequences of the MRI that initially depicted new MM (diagnosis MRI) as well as of a prediagnosis MRI: inclusion of only contrast-enhanced T1-weighted images (CNNdual_ce) was compared with inclusion of also the native T1-weighted images, T2-weighted images, and FLAIR sequences of both time points (CNNdual_all). Second, results were compared with the corresponding single time approaches, in which the CNN was provided exclusively the res...
Source: Investigative Radiology - April 9, 2021 Category: Radiology Tags: Original Articles Source Type: research

Diagnostic Confidence and Feasibility of a Deep Learning Accelerated HASTE Sequence of the Abdomen in a Single Breath-Hold
Objective The aim of this study was to evaluate the feasibility of a single breath-hold fast half-Fourier single-shot turbo spin echo (HASTE) sequence using a deep learning reconstruction (HASTEDL) for T2-weighted magnetic resonance imaging of the abdomen as compared with 2 standard T2-weighted imaging sequences (HASTE and BLADE). Materials and Methods Sixty-six patients who underwent 1.5-T liver magnetic resonance imaging were included in this monocentric, retrospective study. The following T2-weighted sequences in axial orientation and using spectral fat suppression were compared: a conventional respiratory-tr...
Source: Investigative Radiology - April 9, 2021 Category: Radiology Tags: Original Articles Source Type: research

Detection of U-87 Tumor Cells by RGD-Functionalized/Gd-Containing Giant Unilamellar Vesicles in Magnetization Transfer Contrast Magnetic Resonance Images
Conclusions RGD GUVs seem to be interesting carriers that can facilitate the specific accumulation of MRI contrast agents at the tumor region. However, the concentration achieved is still below the threshold needed for T1w-MRI visualization. Conversely, MTC proved to be sufficiently sensitive for the visualization of detectable contrast between pretargeting and posttargeting images. (Source: Investigative Radiology)
Source: Investigative Radiology - April 9, 2021 Category: Radiology Tags: Original Articles Source Type: research

Accelerated Isotropic Multiparametric Imaging by High Spatial Resolution 3D-QALAS With Compressed Sensing: A Phantom, Volunteer, and Patient Study
Conclusions Multiparametric imaging of the whole brain based on 3D-QALAS can be accelerated using CS while preserving tissue quantitative values, tissue segmentation, and quality of synthetic images. (Source: Investigative Radiology)
Source: Investigative Radiology - April 9, 2021 Category: Radiology Tags: Original Articles Source Type: research

Computed Tomography Angiography of the Aorta—Optimization of Automatic Tube Voltage Selection Settings to Reduce Radiation Dose or Contrast Medium in a Prospective Randomized Trial
Objectives The aim of this study was to compare the image quality of low-kV protocols with optimized automatic tube voltage selection (ATVS) settings to reduce either radiation dose or contrast medium (CM) with that of a reference protocol for computed tomography angiography (CTA) of the thoracoabdominal aorta. Materials and Methods In this institutional review board–approved, single-center, prospective randomized controlled trial, 126 patients receiving CTA of the aorta were allocated to one of three computed tomography protocols: (A) reference protocol at 120 kVp and standard weight-adapted CM dose; (B) ...
Source: Investigative Radiology - April 9, 2021 Category: Radiology Tags: Original Articles Source Type: research

A Multicentric Comparison of Apparent Diffusion Coefficient Mapping and the Kaiser Score in the Assessment of Breast Lesions
Objective Materials and Methods In this multicentric study, individual patient data from 3 different centers were analyzed. Consecutive patients receiving standardized multiparametric breast magnetic resonance imaging for standard nonscreening indications were included. At each center, 2 experienced radiologists with more than 5 years of experience retrospectively interpreted the examinations in consensus and applied the KS to every histologically verified lesion. The corresponding mean ADC of each lesion was measured using a Wielema type 4 region of interest. According to established methods, the KS and ADC were c...
Source: Investigative Radiology - April 9, 2021 Category: Radiology Tags: Original Articles Source Type: research

Scientific Advances, Investigative Radiology 2020 (and Beyond)
No abstract available (Source: Investigative Radiology)
Source: Investigative Radiology - April 9, 2021 Category: Radiology Tags: Editorial Source Type: research

Positron Emission Tomography–Magnetic Resonance Imaging Pharmacokinetics, In Vivo Biodistribution, and Whole-Body Elimination of Mn-PyC3A
Conclusions Mn-PyC3A has different pharmacokinetics and is more efficiently eliminated than Mn-DPDP in normal rats. Mn-PyC3A is efficiently eliminated from both normal and 5/6 nephrectomy rats, with increased fractional hepatobiliary excretion from 5/6 nephrectomy rats. Mn-PyC3A is more completely eliminated than Gd-DOTA from 5/6 nephrectomy rats after 7 days. (Source: Investigative Radiology)
Source: Investigative Radiology - March 10, 2021 Category: Radiology Tags: Original Articles Source Type: research

Deep Learning on Conventional Magnetic Resonance Imaging Improves the Diagnosis of Multiple Sclerosis Mimics
Objectives The aims of this study were to present a deep learning approach for the automated classification of multiple sclerosis and its mimics and compare model performance with that of 2 expert neuroradiologists. Materials and Methods A total of 268 T2-weighted and T1-weighted brain magnetic resonance imagin scans were retrospectively collected from patients with migraine (n = 56), multiple sclerosis (n = 70), neuromyelitis optica spectrum disorders (n = 91), and central nervous system vasculitis (n = 51). The neural network architecture, trained on 178 scans, was based on a cascade of 4 three-dimensional con...
Source: Investigative Radiology - March 10, 2021 Category: Radiology Tags: Original Articles Source Type: research

Molecular Magnetic Resonance Imaging of Liver Fibrosis and Fibrogenesis Is Not Altered by Inflammation
Conclusions Both MR probes, EP-3533 and Gd-Hyd, were specific for fibrosis in this model of chronic liver disease regardless of the presence or severity of the underlying inflammation. These results, in addition to previous findings, show the potential application of both molecular MR probes for detection and quantification of fibrosis from various etiologies. Fibrosis is characterized by progressive replacement of normal tissue by extracellular matrix. Diagnosis relies on biopsies as noninvasive methods for detection and quantification of fibrosis are still limited. This work aimed to address the ability of 2 molec...
Source: Investigative Radiology - March 10, 2021 Category: Radiology Tags: Original Articles Source Type: research

Heating of Hip Arthroplasty Implants During Metal Artifact Reduction MRI at 1.5- and 3.0-T Field Strengths
Objectives The aim of this study was to quantify the spatial temperature rises that occur during 1.5- and 3.0-T magnetic resonance imaging (MRI) of different types of hip arthroplasty implants using different metal artifact reduction techniques. Materials and Methods Using a prospective in vitro study design, we evaluated the spatial temperature rises of 4 different total hip arthroplasty constructs using clinical metal artifact reduction techniques including high-bandwidth turbo spin echo (HBW-TSE), slice encoding for metal artifact correction (SEMAC), and compressed sensing SEMAC at 1.5 and 3.0 T. Each MRI pro...
Source: Investigative Radiology - March 10, 2021 Category: Radiology Tags: Original Articles Source Type: research

Classification of Mammographic Breast Microcalcifications Using a Deep Convolutional Neural Network: A BI-RADS–Based Approach
Conclusions The dCNNs can be trained to successfully classify microcalcifications on mammograms according to the BI-RADS classification system in order to act as a standardized quality control tool providing the expertise of a team of radiologists. The goal of this retrospective cohort study was to investigate the potential of a deep convolutional neural network (dCNN) to accurately classify microcalcifications in mammograms with the aim of obtaining a standardized observer-independent microcalcification classification system based on the Breast Imaging Reporting and Data System (BI-RADS) catalog. (Source: Investigative Radiology)
Source: Investigative Radiology - March 10, 2021 Category: Radiology Tags: Original Articles Source Type: research

Bone Marrow Reconversion With Reambulation: A Prospective Clinical Trial
Objectives Methods In a prospective clinical trial, 20 healthy men participated in a 60-day, 6-degree head-down tilt bed rest study. Serial 3-T magnetic resonance (MR) imaging measures of the lumbar spine were performed at baseline, after 57 days of bed rest, and at 30, 360, and 720 days of reambulation (100 MR imaging scans). Proton density with and without fat saturation, 2-point Dixon, and single-voxel MR spectroscopy techniques were used to assess bone marrow composition (300 measures). Erythropoiesis was measured using hematocrit, reticulocyte, and ferritin. Also, participants randomly received either a nutrit...
Source: Investigative Radiology - March 10, 2021 Category: Radiology Tags: Original Articles Source Type: research

Incremental Diagnostic Value of Virtual Noncalcium Dual-Energy Computed Tomography for the Depiction of Cervical Disk Herniation Compared With Standard Gray-Scale Computed Tomography
Objectives The aim of this study was to investigative the diagnostic accuracy of colored dual-energy computed tomography (CT) virtual noncalcium (VNCa) series for analyzing cervical disk herniation compared with standard gray-scale CT images, with magnetic resonance imaging (MRI) serving as standard of reference. Materials and Methods Data from 57 patients who underwent noncontrast dual-source CT and 3.0-Tesla (T) MRI within 2 weeks between January 2017 and December 2018 were retrospectively analyzed. Five radiologists analyzed standard gray-scale dual-energy CT scans for the presence and degree of cervical disk...
Source: Investigative Radiology - March 10, 2021 Category: Radiology Tags: Original Articles Source Type: research

A Targeted Molecular Localization Imaging Method Applied to Tumor Microvasculature
Objectives Ultrasound contrast agents, consisting of gas-filled microbubbles (MBs), have been imaged using several techniques that include ultrasound localization microscopy and targeted molecular imaging. Each of these techniques aims to provide indicators of the disease state but has traditionally been performed independently without co-localization of molecular markers and super-resolved vessels. In this article, we present a new imaging technology: a targeted molecular localization (TML) approach, which uses a single imaging sequence and reconstruction approach to co-localize super-resolved vasculature with molecul...
Source: Investigative Radiology - March 10, 2021 Category: Radiology Tags: Original Articles Source Type: research

Fusion of Preinterventional MR Imaging With Liver Perfusion CT After RFA of Hepatocellular Carcinoma: Early Quantitative Prediction of Local Recurrence
Objectives The aim of this study was to evaluate the ability of fusion of pretreatment magnetic resonance (MR) imaging with posttreatment perfusion–CT (P-CT) after radiofrequency ablation (RFA) of hepatocellular carcinomas (HCCs) and to determine treatment success in an objective, quantitative way. Materials and Methods In this institutional review board–approved study, 39 patients (78.4% male; mean age 68.2 ± 8.5 years) with a total of 43 HCCs, who underwent RFA at our institution and had diagnostic pre-RFA MR imaging and post-RFA P-CT, were included in the study. Post-RFA P-CT was performed ...
Source: Investigative Radiology - February 10, 2021 Category: Radiology Tags: Original Articles Source Type: research

Intraindividual Consistency of Iodine Concentration in Dual-Energy Computed Tomography of the Chest and Abdomen
This study investigates the longitudinal reproducibility of IC in organs, vessels, and lymph nodes in a large cohort of healthy patients who underwent repetitive DECT imaging. Materials and Methods A total of 159 patients, who underwent a total of 469 repetitive (range, 2–4), clinically indicated portal-venous phase DECT examinations of the chest and abdomen, were retrospectively included. At time of imaging, macroscopic tumor burden was excluded by follow-up imaging (≥3 months). Iodine concentration was measured region of interest-based (N = 43) in parenchymatous organs, vessels, lymph nodes, and connectiv...
Source: Investigative Radiology - February 10, 2021 Category: Radiology Tags: Original Articles Source Type: research

A Magnetic Resonance Imaging Radiomics Signature to Distinguish Benign From Malignant Orbital Lesions
The objective was to differentiate benign from malignant orbital lesions using radiomics on 3 T magnetic resonance imaging (MRI) examinations. Materials and Methods This institutional review board–approved prospective single-center study enrolled consecutive patients presenting with an orbital lesion undergoing a 3 T MRI prior to surgery from December 2015 to July 2019. Radiomics features were extracted from 6 MRI sequences (T1-weighted images [WIs], DIXON-T2-WI, diffusion-WI, postcontrast DIXON-T1-WI) using the Pyradiomics software. Features were selected based on their intraobserver and interobserver reprodu...
Source: Investigative Radiology - February 10, 2021 Category: Radiology Tags: Original Articles Source Type: research

Age-Related Changes in Relaxation Times, Proton Density, Myelin, and Tissue Volumes in Adult Brain Analyzed by 2-Dimensional Quantitative Synthetic Magnetic Resonance Imaging
This study aimed to reveal the changes in tissue characteristics and volumes of the brain according to age and provide age-specific reference values obtained by quantitative synthetic MRI. Materials and Methods This was a prospective study of healthy subjects with no history of brain diseases scanned with a multidynamic multiecho sequence for simultaneous measurement of relaxometry of T1, T2, and PD. We performed myelin estimation and brain volumetry based on these values. We performed volume-of-interest analysis on both gray matter (GM) and white matter (WM) regions for T1, T2, PD, and myelin volume fraction maps. ...
Source: Investigative Radiology - February 10, 2021 Category: Radiology Tags: Original Articles Source Type: research

Safety and Oncologic Outcomes of Magnetic Resonance Imaging–Guided Cryoablation of Renal Cell Carcinoma: A 10-Year Single-Center Experience
Objectives Magnetic resonance imaging guidance has been sporadically reported for renal tumor cryoablation (CA); therefore, clinical experience with this modality is still limited. The aim of this study is to retrospectively analyze our 10-year experience with renal tumor CA performed on a 1.5 T magnetic resonance imaging unit with the intent of reporting procedural safety and oncologic outcomes. Materials and Methods We included 143 patients (102 men; 41 women; median age, 73 years; range, 34–91 years) with 149 tumors (median size, 2.6 cm; range, 0.6–6.0 cm), treated between 2009 and 2019. Patien...
Source: Investigative Radiology - February 10, 2021 Category: Radiology Tags: Original Articles Source Type: research

Differentiation of Crystals Associated With Arthropathies by Spectral Photon-Counting Radiography: A Proof-of-Concept Study
Objectives The aims of this study were to test whether spectral photon-counting radiography (SPCR) is able to identify and distinguish different crystals associated with arthropathies in vitro and to validate findings in a gouty human third toe ex vivo. Materials and Methods Industry-standard calibration rods of calcium pyrophosphate, calcium hydroxyapatite (HA), and monosodium urate (MSU) were scanned with SPCR in an experimental setup. Each material was available at 3 different concentrations, and a dedicated photon-counting detector was used for SPCR, whereas validation scans were obtained on a clinical dual-...
Source: Investigative Radiology - February 10, 2021 Category: Radiology Tags: Original Articles Source Type: research

MRI-Guided Focused Ultrasound of Osseous Metastases: Treatment Parameters Associated With Successful Pain Reduction
Background A phase 3 multicenter trial demonstrated that magnetic resonance imaging (MRI)–guided focused ultrasound (US) is a safe, noninvasive treatment that alleviated pain from bone metastases. However, outcomes varied among institutions (from 0%–100% treatment success). Purpose The aim of this study was to identify patient selection, technical treatment, and imaging parameters that predict successful pain relief of osseous metastases after MRI-guided focused US. Materials and Methods This was a secondary analysis of a phase 3 clinical study that included participants who received MRI-guide...
Source: Investigative Radiology - February 10, 2021 Category: Radiology Tags: Original Articles Source Type: research

Proof of Concept: Phantom Study to Ensure Quality and Safety of Portable Chest Radiography Through Glass During the COVID-19 Pandemic
Conclusions Good-quality portable chest radiographs can be obtained safely through the smart glass doors of the isolation room. However, this technique does result in minor backscatter radiation. Modifications in the exposure factors (such as increasing milliampere seconds) may be required to optimize image quality while using this technique. (Source: Investigative Radiology)
Source: Investigative Radiology - February 10, 2021 Category: Radiology Tags: Original Articles Source Type: research

T1-Based Synthetic Magnetic Resonance Contrasts Improve Multiple Sclerosis and Focal Epilepsy Imaging at 7 T
Objectives Ultra-high field magnetic resonance imaging (MRI) (≥7 T) is a unique opportunity to improve the clinical diagnosis of brain pathologies, such as multiple sclerosis or focal epilepsy. However, several shortcomings of 7 T MRI, such as radiofrequency field inhomogeneities, could degrade image quality and hinder radiological interpretation. To address these challenges, an original synthetic MRI method based on T1 mapping achieved with the magnetization-prepared 2 rapid acquisition gradient echo (MP2RAGE) sequence was developed. The radiological quality of on-demand T1-based contrasts generated by this techniq...
Source: Investigative Radiology - January 8, 2021 Category: Radiology Tags: Original Articles Source Type: research

Characterization of Leukoencephalopathy and Association With Later Neurocognitive Performance in Pediatric Acute Lymphoblastic Leukemia
This study aims to objectively characterize the prevalence, extent, and intensity of LE, and their association with later neurocognitive performance. Materials and Methods Pediatric patients (N = 377) treated for ALL without irradiation underwent MR neuroimaging at 4 time points throughout therapy (end of remission induction [MR1], end of consolidation [MR2], and week 31 [MR3] and week 120 [end therapy, MR4] of continuation treatment) and neurocognitive evaluations at the end of therapy and 2 years later. Generalized estimation equation models with logit link were developed to explore the association between LE prev...
Source: Investigative Radiology - January 8, 2021 Category: Radiology Tags: Original Articles Source Type: research

Added Value of CT Arterial Subtraction Images in Liver Imaging Reporting and Data System Treatment Response Categorization for Transcatheter Arterial Chemoembolization-Treated Hepatocellular Carcinoma
Conclusions The LR-TR viable category is highly specific but inadequately sensitive for detecting viable tumor in TACE-treated HCC on conventional multiphasic CT. Adding arterial subtraction images to the conventional CT images significantly increases sensitivity without compromising the specificity and improves the diagnostic confidence of LR-TR viable category. (Source: Investigative Radiology)
Source: Investigative Radiology - January 8, 2021 Category: Radiology Tags: Original Articles Source Type: research

Can a Novel Deep Neural Network Improve the Computer-Aided Detection of Solid Pulmonary Nodules and the Rate of False-Positive Findings in Comparison to an Established Machine Learning Computer-Aided Detection?
Conclusions The new deep learning–based CAD software (VD20A) shows similar sensitivity with the conventional CAD software (VD10F), but a significantly higher specificity. (Source: Investigative Radiology)
Source: Investigative Radiology - January 8, 2021 Category: Radiology Tags: Original Articles Source Type: research

Measured Multipoint Ultra-High b-Value Diffusion MRI in the Assessment of MRI-Detected Prostate Lesions
Conclusions Despite evaluation of a large b-value range and inclusion of 2-point, multipoint, and kurtosis models, none of the parameters provided better predictive performance than standard 2-point ADC measurements using b-values 50/1000 or 50/1500. Our results suggest that most of the diagnostic benefits available in diffusion MRI are already represented in an ADC composed of one low and one 1000 to 1500 s/mm2 b-value. (Source: Investigative Radiology)
Source: Investigative Radiology - January 8, 2021 Category: Radiology Tags: Original Articles Source Type: research

Magnetization Transfer Imaging Predicts Porcine Kidney Recovery After Revascularization of Renal Artery Stenosis
Conclusions Renal STK-MTR, particularly at 600 Hz offset, is sensitive to hemodynamic changes after PTRA in swine RVD and capable of noninvasively predicting post-PTRA kidney perfusion, RBF, and fibrosis. Therefore, STK-MTR may be a valuable tool to predict renal hemodynamic and functional recovery, as well as residual kidney fibrosis after revascularization in RVD. Magnetization transfer imaging is a novel noninvasive tool for the detection of kidney fibrosis, but its association with kidney function and hemodynamics is unclear. Renovascular disease (RVD) associated with metabolic derangements elicits renal fibrosi...
Source: Investigative Radiology - January 8, 2021 Category: Radiology Tags: Original Articles Source Type: research

A Deep Learning Model for the Accurate and Reliable Classification of Disc Degeneration Based on MRI Data
Conclusions With a reliability of κ> 0.9, our system clearly outperforms average human interrater as well as intrarater reliability. With an average sensitivity of more than 90%, our classifier also surpasses state-of-the-art machine learning solutions for automatically grading disc degeneration. (Source: Investigative Radiology)
Source: Investigative Radiology - January 8, 2021 Category: Radiology Tags: Original Articles Source Type: research

Two-Minute Quantitative Susceptibility Mapping From Three-Dimensional Echo-Planar Imaging: Accuracy, Reliability, and Detection Performance in Patients With Cerebral Microbleeds
Objectives The aim of this study was to assess the accuracy, reliability, and cerebral microbleed (CMB) detection performance of 2-minute quantitative susceptibility mapping (QSM) from 3-dimensional echo-planar imaging (3D-EPI). Materials and Methods Gadolinium phantom study was conducted using 3D-EPI, single–echo time (TE), and multi-TE gradient-recalled echo (GRE) sequences on two 3-T magnetic resonance (MR) scanners to assess the accuracy between measured and theoretical susceptibility values. The institutional review board approved this prospective study, and 40 healthy volunteers were enrolled with wr...
Source: Investigative Radiology - January 8, 2021 Category: Radiology Tags: Original Articles Source Type: research

CT Dosimetry: What Has Been Achieved and What Remains to Be Done
Radiation dose in computed tomography (CT) has become a hot topic due to an upward trend in the number of CT procedures worldwide and the relatively high doses associated with these procedures. The main aim of this review article is to provide an overview of the most frequently used metrics for CT radiation dose characterization, discuss their strengths and limitations, and present patient dose assessment methods. Computed tomography dosimetry is still based on a CT dose index (CTDI) measured using 100-mm-long pencil ionization chambers and standard dosimetry phantoms (CTDI100). This dose index is easily measured but has i...
Source: Investigative Radiology - December 11, 2020 Category: Radiology Tags: Review Articles Source Type: research

Ultrasound Contrast: Gas Microbubbles in the Vasculature
Gas-filled microbubbles are currently in clinical use as blood pool contrast agents for ultrasound imaging. The goal of this review is to discuss the trends and issues related to these relatively unusual intravascular materials, which are not small molecules per se, not polymers, not even nanoparticles, but larger micrometer size structures, compressible, flexible, elastic, and deformable. The intent is to connect current research and initial studies from 2 to 3 decades ago, tied to gas exchange between the bubbles and surrounding biological medium, in the following areas of focus: (1) parameters of microbubble movement in...
Source: Investigative Radiology - December 11, 2020 Category: Radiology Tags: Review Articles Source Type: research

The Role of Magnetic Resonance Imaging in (Future) Cancer Staging: Note the Nodes
The presence or absence of lymph node metastases is a very important prognostic factor in patients with solid tumors. Current invasive and noninvasive diagnostic methods for N-staging like lymph node dissection, morphologic computed tomography/magnetic resonance imaging (MRI), or positron emission tomography–computed tomography have significant limitations because of technical, biological, or anatomical reasons. Therefore, there is a great clinical need for more precise, reliable, and noninvasive N-staging in patients with solid tumors. Using ultrasmall superparamagnetic particles of ironoxide (USPIO)-enhanced MRI of...
Source: Investigative Radiology - December 11, 2020 Category: Radiology Tags: Review Articles Source Type: research

Alternatives to Gadolinium-Based Contrast Agents
Gadolinium-based contrast agents have been used in hundreds of millions of patients in the past 30 years, with an exemplary safety record. However, assumptions made at their inception have been recently challenged, rekindling innovation efforts. This critical review outlines the motivations, technical obstacles, problems, and the most recent published progress toward the creation of alternatives to the existing gadolinium-based contrast agent. (Source: Investigative Radiology)
Source: Investigative Radiology - December 11, 2020 Category: Radiology Tags: Review Articles Source Type: research

Molecular MR Contrast Agents
We describe the requirements for a successful molecular MR contrast agent and the challenges for clinical translation. The review highlights work from the last 5 years and places an emphasis on new contrast agents that have been validated in multiple preclinical models. Applications of molecular MR include imaging of inflammation, fibrosis, fibrogenesis, thromboembolic disease, and cancers. Molecular MR is positioned to move beyond detection of disease to the quantitative staging of disease and measurement of treatment response. (Source: Investigative Radiology)
Source: Investigative Radiology - December 11, 2020 Category: Radiology Tags: Review Articles Source Type: research

A Comprehensive View on MRI Techniques for Imaging Blood-Brain Barrier Integrity
The blood-brain barrier (BBB) is the interface between the blood and brain tissue, which regulates the maintenance of homeostasis within the brain. Impaired BBB integrity is increasingly associated with various neurological diseases. To gain a better understanding of the underlying processes involved in BBB breakdown, magnetic resonance imaging (MRI) techniques are highly suitable for noninvasive BBB assessment. Commonly used MRI techniques to assess BBB integrity are dynamic contrast-enhanced and dynamic susceptibility contrast MRI, both relying on leakage of gadolinium-based contrast agents. A number of conceptually diff...
Source: Investigative Radiology - December 11, 2020 Category: Radiology Tags: Review Articles Source Type: research

Toward Quantification: Microstructure and Magnetic Resonance Fingerprinting
Quantitative magnetic resonance imaging (MRI) is a long-standing challenge. We advocate that the origin of the problem is the simplification applied in commonly used models of the MRI signal relation to the target parameters of biological tissues. Two research fields are briefly reviewed as ways to respond to the challenge of quantitative MRI, both experiencing an exponential growth right now. Microstructure MRI strives to build physiology-based models from cells to signal and, given the signal, back to the cells again. Magnetic resonance fingerprinting aims at efficient simultaneous determination of multiple signal parame...
Source: Investigative Radiology - December 11, 2020 Category: Radiology Tags: Review Articles Source Type: research

Impact of Confounding Thoracic Tubes and Pleural Dehiscence Extent on Artificial Intelligence Pneumothorax Detection in Chest Radiographs
Conclusions Our detailed subgroup analysis demonstrated that the performance of established AI algorithms for PTX detection trained on public datasets strongly depends on PTX size and is significantly biased by confounding image features, such as inserted TTS. Our established, clinically relevant and radiologically annotated benchmarking cohort might be of great benefit for ongoing algorithm development. (Source: Investigative Radiology)
Source: Investigative Radiology - November 7, 2020 Category: Radiology Tags: Original Articles Source Type: research

Contrast Saline Mixture DualFlow Injection Protocols for Low-Kilovolt Computed Tomography Angiography: A Systematic Phantom and Animal Study
Conclusion DualFlow injection protocols can be tailored for low-kV CTA by reducing the IDR while overall flow rate remains unchanged. Although no differences in attenuation were found, DF injections offer a shorter time to peak closer to the reference 120 kV protocol. This allows the use of DF injection protocols to calibrate bolus density in low-kV CTA and yields the potential for a more individualized CM administration. (Source: Investigative Radiology)
Source: Investigative Radiology - November 7, 2020 Category: Radiology Tags: Original Articles Source Type: research