Evolution in Computed Tomography: The Battle for Speed and Dose
Abstract: The advent of computed tomography (CT) has revolutionized radiology. Starting as head-only scanners, modern CT systems are now capable of performing whole-body examinations within a couple of seconds in isotropic resolution. Technical advancements of scanner hardware and image reconstruction techniques are reviewed and discussed in their clinical context. These improvements have led to a steady increase of CT examinations in all age groups for a number of reasons. On the one hand, it is very easy today to obtain whole-body data for oncologic staging and follow-up or for trauma imaging. On the other hand, new exam...
Source: Investigative Radiology - August 10, 2015 Category: Radiology Tags: Review Articles Source Type: research

The Changing World of Breast Cancer: A Radiologist's Perspective
Abstract: Compared with other fields of medicine, there is hardly an area that has seen such fast development as the world of breast cancer. Indeed, the way we treat breast cancer has changed fundamentally over the past decades. Breast imaging has always been an integral part of this change, and it undergoes constant adjustment to new ways of thinking. This relates not only to the technical tools we use for diagnosing breast cancer but also to the way diagnostic information is used to guide treatment. There is a constant change of concepts for and attitudes toward breast cancer, and a constant flux of new ideas, new treatm...
Source: Investigative Radiology - August 10, 2015 Category: Radiology Tags: Review Articles Source Type: research

Internal Derangements of Joints—Past, Present, and Future
This article analyzes the patterns of innovation that were essential for the transformation of musculoskeletal radiology. Furthermore, state-of- the-art joint imaging is described through 9 key concepts, including both cutting-edge clinical applications as well as topics at the forefront of musculoskeletal research. Eventually, emerging trends are outlined that will likely shape musculoskeletal radiology in the next decades. (Source: Investigative Radiology)
Source: Investigative Radiology - August 10, 2015 Category: Radiology Tags: Review Articles Source Type: research

Multiparametric Magnetic Resonance Imaging in Prostate Cancer Management: Current Status and Future Perspectives
This article reviews recent and ongoing developments in multiparametric magnetic resonance imaging (mpMRI) of the prostate. Advances in T2-weighted imaging, diffusion-weighted imaging, dynamic contrast-enhanced imaging, and spectroscopic imaging are described along with advances related to radiofrequency coils and imaging at high magnetic field. As mpMRI is increasingly becoming routine in various aspects of clinical prostate cancer management, its role in detection, localization, staging, assessment of aggressiveness, and active surveillance is discussed. Combined with growing clinical adoption of the techniques already a...
Source: Investigative Radiology - August 10, 2015 Category: Radiology Tags: Review Articles Source Type: research

Fifty Years of Technological Innovation: Potential and Limitations of Current Technologies in Abdominal Magnetic Resonance Imaging and Computed Tomography
Abstract: Magnetic resonance imaging (MRI) has become an important modality for the diagnosis of intra-abdominal pathology. Hardware and pulse sequence developments have made it possible to derive not only morphologic but also functional information related to organ perfusion (dynamic contrast-enhanced MRI), oxygen saturation (blood oxygen level dependent), tissue cellularity (diffusion-weighted imaging), and tissue composition (spectroscopy). These techniques enable a more specific assessment of pathologic lesions and organ functionality. Magnetic resonance imaging has thus transitioned from a purely morphologic examinati...
Source: Investigative Radiology - August 10, 2015 Category: Radiology Tags: Review Articles Source Type: research

Quantitative Computed Tomography Imaging Biomarkers in the Diagnosis and Management of Lung Cancer
Abstract: Tumor diameter has traditionally been used as a standard metric in terms of diagnosis and prognosis prediction of lung cancer. However, recent advances in imaging techniques and data analyses have enabled novel quantitative imaging biomarkers that can characterize disease status more comprehensively and/or predict tumor behavior more precisely. The most widely used imaging modality for lung tumor assessment is computed tomography. Therefore, we focused on computed tomography imaging biomarkers such as tumor volume and mass, ground-glass opacities, perfusion parameters, as well as texture features in this review. ...
Source: Investigative Radiology - August 10, 2015 Category: Radiology Tags: Review Articles Source Type: research

Cardiovascular Imaging: The Past and the Future, Perspectives in Computed Tomography and Magnetic Resonance Imaging
Abstract: Today’s noninvasive imaging of the cardiovascular system has revolutionized the approach to various diseases and has substantially affected prognostic information. Cardiovascular magnetic resonance (MR) and computed tomographic (CT) imaging are at center stage of these approaches, although 5 decades ago, these technologies were unheard of. Both modalities had their inception in the 1970s with a primary focus on noncardiovascular applications. The technical development of the various decades, however, substantially pushed the envelope for cardiovascular MR and CT applications. Within the past 10–15 yea...
Source: Investigative Radiology - August 10, 2015 Category: Radiology Tags: Review Articles Source Type: research

Magnetic Resonance Imaging and Computed Tomography of the Brain—50 Years of Innovation, With a Focus on the Future
Abstract: This review focuses specifically on the developments in brain imaging, as opposed to the spine, and specifically conventional, clinical, cross-sectional imaging, looking primarily at advances in magnetic resonance imaging (MRI) and computed tomography (CT). These fields are viewed from a perspective of landmark publications in the last 50 years and subsequently more in depth using sentinel publications from the last 5 years. It is also written from a personal perspective, with the authors having witnessed the evolution of both fields from their initial clinical introduction to their current state. Both CT and MRI...
Source: Investigative Radiology - August 10, 2015 Category: Radiology Tags: Review Articles Source Type: research

Fifty Years of the Best of Investigative Radiology
No abstract available (Source: Investigative Radiology)
Source: Investigative Radiology - August 10, 2015 Category: Radiology Tags: Editorial Source Type: research

T1-Weighted Contrast-Enhanced Magnetic Resonance Imaging of the Small Bowel: Comparison Between 1.5 and 7 T
Conclusions: T1-weighted contrast-enhanced MRI of the small bowel at 7 T represents a promising MR technique for establishing ultra-high magnetic field strengths in clinical applications. Despite increased artifacts at 7 T, depiction of the small bowel was achieved with comparable quality to the current state-of-the-art field strength of 1.5 T. Assessment of potential diagnostic benefits should be the focus of future high-field MRI studies. (Source: Investigative Radiology)
Source: Investigative Radiology - July 12, 2015 Category: Radiology Tags: Original Articles Source Type: research

Evaluation of A New Bolus Tracking–Based Algorithm for Predicting A Patient-Specific Time of Arterial Peak Enhancement in Computed Tomography Angiography
Conclusions: The new algorithm can robustly predict a patient-specific time of arterial peak enhancement and is better than a best-case scenario for the current bolus tracking technique because interpatient variations are taken into account. It offers a new framework for scan timing optimization and can potentially be used for personalized scan timing in real time. (Source: Investigative Radiology)
Source: Investigative Radiology - July 12, 2015 Category: Radiology Tags: Original Articles Source Type: research

Quantitative Susceptibility Mapping at 3 T and 1.5 T: Evaluation of Consistency and Reproducibility
Conclusions: Quantitative susceptibility mapping with HARPERELLA and V-SHARP demonstrated good reproducibility at 3 T and 1.5 T, and QSM with V-SHARP demonstrated good consistency at 3 T and 1.5 T. (Source: Investigative Radiology)
Source: Investigative Radiology - July 12, 2015 Category: Radiology Tags: Original Articles Source Type: research

Collimation and Image Quality of C-Arm Computed Tomography: Potential of Radiation Dose Reduction While Maintaining Equal Image Quality
Conclusions: Craniocaudal collimation in CACT should be used whenever possible to increase the image quality and reduce the patient's overall radiation exposure. Therefore, new smart acquisition protocols are required for collimated CACT to improve the trade-off between radiation exposure and image quality requirements considering the collimation used. (Source: Investigative Radiology)
Source: Investigative Radiology - July 12, 2015 Category: Radiology Tags: Original Articles Source Type: research

Positron Emission Tomography/Magnetic Resonance Imaging for Local Tumor Staging in Patients With Primary Breast Cancer: A Comparison With Positron Emission Tomography/Computed Tomography and Magnetic Resonance Imaging
Conclusions: Integrated PET/MRI does not provide diagnostic advantages for local tumor staging of breast cancer patients in comparison to MRI alone. Positron emission tomography/MRI and MRI enable an improved determination of the local tumor extent in comparison to PET/CT, whereas all 3 imaging modalities offer a comparable diagnostic performance for the identification of axillary disease. (Source: Investigative Radiology)
Source: Investigative Radiology - July 12, 2015 Category: Radiology Tags: Original Articles Source Type: research

Diffusion Tensor Imaging Adds Diagnostic Accuracy in Magnetic Resonance Neurography
Objective: The aim of this study was to determine whether quantitative diffusion tensor imaging (DTI) adds diagnostic accuracy in magnetic resonance neurography. Materials and Methods: This prospective study was approved by the institutional review board. We enrolled 16 patients with peripheral polyneuropathy of various etiologies involving the upper arm and 30 healthy controls. Magnetic resonance neurography was performed at 3 T using transverse T2-weighted (T2-w) turbo spin echo and spin echo planar imaging diffusion-weighted sequences. T2-weighted normalized signal (nT2), fractional anisotropy (FA), apparent diffusion c...
Source: Investigative Radiology - July 12, 2015 Category: Radiology Tags: Original Articles Source Type: research

Multiparametric Magnetic Resonance Imaging for Discriminating Low-Grade From High-Grade Prostate Cancer
Conclusions: Multiparametric MRI is a useful tool for the discrimination between low-grade and high-grade PCa and performs better than any individual functional parameter in both the PZ and TZ. The 25th percentile of ADC + WO25 offered the optimal combination in the PZ, and the choline over spermine + creatine ratio + WO25 offered the optimal combination in the TZ. The ADC parameter has no additional value for the assessment of PCa aggressiveness in the TZ. (Source: Investigative Radiology)
Source: Investigative Radiology - July 12, 2015 Category: Radiology Tags: Original Articles Source Type: research

Evaluation of Diffusion Kurtosis Imaging Versus Standard Diffusion Imaging for Detection and Grading of Peripheral Zone Prostate Cancer
Objectives: The purpose of the study was to evaluate and validate diffusion kurtosis imaging (DKI) for detection grading of peripheral zone prostate cancer (PCa) compared with standard diffusion-weighted imaging (DWI) in a cohort of patients with biopsy-proven PCa. Materials and Methods: In this retrospective, single-institutional study, 55 patients (age, 67.5 ± 6.9 years; range, 52–84 years) who underwent multiparametric magnetic resonance imaging (MRI) before transperineal magnetic resonance/transrectal ultrasound-guided fusion biopsy were included. Suspicious lesions identified in multiparametric MRI underw...
Source: Investigative Radiology - July 12, 2015 Category: Radiology Tags: Original Articles Source Type: research

Commentary on T1-Weighted Hypersignal in the Deep Cerebellar Nuclei After Repeated Administrations of Gadolinium-Based Contrast Agents in Healthy Rats: Difference Between Linear and Macrocyclic Agents
No abstract available (Source: Investigative Radiology)
Source: Investigative Radiology - July 12, 2015 Category: Radiology Tags: Commentary Source Type: research

T1-Weighted Hypersignal in the Deep Cerebellar Nuclei After Repeated Administrations of Gadolinium-Based Contrast Agents in Healthy Rats: Difference Between Linear and Macrocyclic Agents
Objectives: To prospectively compare in healthy rats the effect of multiple injections of macrocyclic (gadoterate meglumine) and linear (gadodiamide) gadolinium-based contrast agents (GBCAs) on T1-weighted signal intensity in the deep cerebellar nuclei (DCN), including the dentate nucleus. Materials and Methods: Healthy rats (n = 7/group) received 20 intravenous injections of 0.6 mmol of gadolinium (Gd) per kilogram (4 injections per week during 5 weeks) of gadodiamide, gadoterate meglumine, or hyperosmolar saline (control group). Brain T1-weighted magnetic resonance imaging was performed before and once a week during the ...
Source: Investigative Radiology - July 12, 2015 Category: Radiology Tags: Original Article Source Type: research

Gadodiamide and Dentate Nucleus T1 Hyperintensity in Patients With Meningioma Evaluated by Multiple Follow-Up Contrast-Enhanced Magnetic Resonance Examinations With No Systemic Interval Therapy
Abstract: The dentate nucleus of the cerebellum may appear as hyperintense on unenhanced T1 magnetic resonance images (MRIs) of the brain. Recently, T1 signal hyperintensity has received attention owing to data on the association of this finding with the history of multiple injections of gadolinium-based contrast agents, specifically gadodiamide, in patients with multiple sclerosis and brain metastases.  We conducted a retrospective study on patients with a meningioma who had routinely undergone follow-up enhanced MRI scans with gadodiamide. Across a time interval of 18 months (from January 2013 to July 2014), we iden...
Source: Investigative Radiology - June 10, 2015 Category: Radiology Tags: Technical Note Source Type: research

Computed Tomography Angiography With High Flow Rates: An In Vitro and In Vivo Feasibility Study
Conclusions: These results indicate that injections with 9 mL/s using high-flow injection needles are safe. The pressure limit of 325 psi was not reached, and the injections resulted in diagnostic attenuation values. Using this dedicated needle, high flow rates should not be considered a drawback for CM application in routine CT angiography examinations. (Source: Investigative Radiology)
Source: Investigative Radiology - June 10, 2015 Category: Radiology Tags: Original Articles Source Type: research

Simultaneous Multislice Echo Planar Imaging With Blipped Controlled Aliasing in Parallel Imaging Results in Higher Acceleration: A Promising Technique for Accelerated Diffusion Tensor Imaging of Skeletal Muscle
Objective: The aim of this study was to investigate the feasibility of accelerated diffusion tensor imaging (DTI) of skeletal muscle using echo planar imaging (EPI) applying simultaneous multislice excitation with a blipped controlled aliasing in parallel imaging results in higher acceleration unaliasing technique. Materials and Methods: After federal ethics board approval, the lower leg muscles of 8 healthy volunteers (mean [SD] age, 29.4 [2.9] years) were examined in a clinical 3-T magnetic resonance scanner using a 15-channel knee coil. The EPI was performed at a b value of 500 s/mm2 without slice acceleration (conventi...
Source: Investigative Radiology - June 10, 2015 Category: Radiology Tags: Original Articles Source Type: research

Feasibility of Selective Catheter-Directed Coronary Computed Tomography Angiography Using Ultralow-Dose Intracoronary Contrast Injection in a Swine Model
Conclusions: The current findings demonstrate the feasibility of selective CCTA using ultralow-dose intracoronary contrast injection. This technique may provide additional means of coronary evaluation in patients who may require strategic planning before a procedure using a combined modality system. (Source: Investigative Radiology)
Source: Investigative Radiology - June 10, 2015 Category: Radiology Tags: Original Articles Source Type: research

Real-Time In Vivo Characterization of Primary Liver Tumors With Diffuse Optical Spectroscopy During Percutaneous Needle Interventions: Feasibility Study in Woodchucks
This study presents the first in vivo real-time optical tissue characterization during image-guided percutaneous intervention using near-infrared diffuse optical spectroscopy sensing at the tip of a needle. The goal of this study was to indicate transition boundaries from healthy tissue to tumors, namely, hepatic carcinoma, based on the real-time feedback derived from the optical measurements. Materials and Methods: Five woodchucks with hepatic carcinoma were used for this study. The woodchucks were imaged with contrast-enhanced cone beam computed tomography with a flat panel detector C-arm system to visualize the carcinom...
Source: Investigative Radiology - June 10, 2015 Category: Radiology Tags: Original Articles Source Type: research

Utility of Magnetic Resonance Imaging to Monitor Surgical Meshes: Correlating Imaging and Clinical Outcome of Patients Undergoing Inguinal Hernia Repair
Conclusions: Our results suggest that the actual postoperative mesh position after release of laparoscopic pneumoperitoneum may deviate from its position during surgery. Gross mesh position and configuration differed between patients but did not change within a given patient over the observation period of 3 months after surgery. We did not find a correlation between clinical symptoms and mesh configuration or position. Shrinkage of meshes does occur, yet not as concentric process, but regionally variable, leading to a reduced hernia coverage of up to −20% in the lateral and posterior directions. (Source: Investigative Radiology)
Source: Investigative Radiology - June 10, 2015 Category: Radiology Tags: Original Articles Source Type: research

In Vivo Dark-Field Radiography for Early Diagnosis and Staging of Pulmonary Emphysema
Conclusions: X-ray dark-field radiography can reliably visualize different stages of emphysema in vivo and demonstrates significantly higher diagnostic accuracy for early stages of emphysema than conventional attenuation-based radiography. (Source: Investigative Radiology)
Source: Investigative Radiology - June 10, 2015 Category: Radiology Tags: Original Articles Source Type: research

Incorporation of Time-of-Flight Information Reduces Metal Artifacts in Simultaneous Positron Emission Tomography/Magnetic Resonance Imaging: A Simulation Study
Conclusions: Positron emission tomographic imaging benefits from the integration of TOF information in simultaneous PET/MR. The inclusion of TOF information in simultaneous PET/MR imaging reduces errors related to metal artifacts at the site of the artifact. (Source: Investigative Radiology)
Source: Investigative Radiology - June 10, 2015 Category: Radiology Tags: Original Articles Source Type: research

Nephrogenic Systemic Fibrosis Risk After Liver Magnetic Resonance Imaging With Gadoxetate Disodium in Patients With Moderate to Severe Renal Impairment: Results of a Prospective, Open-Label, Multicenter Study
Conclusions: Gadoxetate disodium in patients with moderate to severe renal impairment did not raise any clinically significant safety concern. No NSF cases were observed. (Source: Investigative Radiology)
Source: Investigative Radiology - May 13, 2015 Category: Radiology Tags: Original Articles Source Type: research

Diagnostic Accuracy of Diffusion-Weighted Magnetic Resonance Imaging Versus Positron Emission Tomography/Computed Tomography for Early Response Assessment of Liver Metastases to Y90-Radioembolization
Objectives: Patients with hepatic metastases who are candidates for Y90-radioembolization (Y90-RE) usually have advanced tumor stages with involvement of both liver lobes. Per current guidelines, these patients have usually undergone several cycles of potentially hepatotoxic systemic chemotherapy before Y90-RE is at all considered, requiring split (lobar) treatment sessions to reduce hepatic toxicity. Assessing response to Y90-RE early, that is, already after the first lobar session, would be helpful to avoid an ineffective and potentially hepatotoxic second lobar treatment. We investigated the accuracy with which diffusio...
Source: Investigative Radiology - May 13, 2015 Category: Radiology Tags: Original Articles Source Type: research

Three-Dimensional Black-Blood T1-Weighted Turbo Spin-Echo Techniques for the Diagnosis of Deep Vein Thrombosis in Comparison With Contrast-Enhanced Magnetic Resonance Imaging: A Pilot Study
The objective of this study was to evaluate the feasibility of a novel 3-dimensional turbo spin-echo technique with isotropic resolution for the diagnosis of deep vein thrombosis (DVT) in comparison with contrast-enhanced magnetic resonance imaging (CE-MRI) and sonography. Materials and Methods: Thirteen patients (8 males, 17–93 years) with proven DVT in duplex ultrasound (n = 11) or with pulmonary embolism and suspected to have DVT (n = 2) were consecutively imaged at 3.0 T with 1.2-mm isotropic-resolution volumetric isotropic turbo spin-echo acquisition (VISTA). Sensitivity (SE), specificity (SP), positive and nega...
Source: Investigative Radiology - May 13, 2015 Category: Radiology Tags: Original Articles Source Type: research

Susceptibility-Weighted Angiography Visualizes Hypoxia in Cerebral Veins
Conclusions: Hypoxia leads to visible and measurable changes in cerebral veins as depicted through SWAN. Possible clinical implications of this finding include stroke and tumor imaging and need further investigation. (Source: Investigative Radiology)
Source: Investigative Radiology - May 13, 2015 Category: Radiology Tags: Original Articles Source Type: research

Effect of Iodinated Contrast Medium in Diabetic Rat Kidneys as Evaluated by Blood-Oxygenation-Level–Dependent Magnetic Resonance Imaging and Urinary Neutrophil Gelatinase-Associated Lipocalin
Conclusions: The STZ-induced diabetic rat may be suitable for studying the effects of iodinated contrast on renal oxygenation status and may mimic human condition closer than the pretreatment model described before. The peak R2* value and initial upslope of R2* in ISOM appear to be effective magnetic resonance imaging markers to predict renal injury after administration of an iodinated contrast agent. (Source: Investigative Radiology)
Source: Investigative Radiology - May 13, 2015 Category: Radiology Tags: Technical Note Source Type: research

Contrast-Enhanced C-arm Computed Tomography Imaging of Myocardial Infarction in the Interventional Suite
Objectives: Cardiac C-arm computed tomography (CT) uses a standard C-arm fluoroscopy system rotating around the patient to provide CT-like images during interventional procedures without moving the patient to a conventional CT scanner. We hypothesized that C-arm CT can be used to visualize and quantify the size of perfusion defects and late enhancement resulting from a myocardial infarction (MI) using contrast-enhanced techniques similar to previous CT and magnetic resonance imaging studies. Materials and Methods: A balloon occlusion followed by reperfusion in a coronary artery was used to study acute and subacute MI in 12...
Source: Investigative Radiology - May 13, 2015 Category: Radiology Tags: Original Articles Source Type: research

Magnetic Resonance-Based Visualization of Thermal Ablative Margins Around Hepatic Tumors by Means of Systemic Ferucarbotran Administration Before Radiofrequency Ablation: Animal Study to Reveal the Connection Between Excess Iron Deposition and T2*-Weighted Hypointensity in Ablative Margins
Conclusions: The RFA of ferucarbotran-accumulated healthy liver tissues in the rats caused excess iron deposition in the ablated liver tissues and produced sustained T2*-weighted hypointense regions. Similar hypointense regions surrounding hepatic tumors were indicative of ablative margins. (Source: Investigative Radiology)
Source: Investigative Radiology - May 13, 2015 Category: Radiology Tags: Original Articles Source Type: research

Free-Breathing Liver Perfusion Imaging Using 3-Dimensional Through-Time Spiral Generalized Autocalibrating Partially Parallel Acquisition Acceleration
Conclusions: This high–spatiotemporal resolution free-breathing 3D liver imaging technique allows voxelwise quantification of liver perfusion. (Source: Investigative Radiology)
Source: Investigative Radiology - May 13, 2015 Category: Radiology Tags: Original Articles Source Type: research

Neuroradiology: The Essentials With MR and CT, 1st Edition Val M. Runge, Wendy R.K. Smoker, and Antonios Valavanis New York, NY: Thieme Publishers 256 pp, 1138 illustrations
No abstract available (Source: Investigative Radiology)
Source: Investigative Radiology - April 17, 2015 Category: Radiology Tags: Book Review Source Type: research

Color-Coded Cerebral Computed Tomographic Angiography: Implementation of a Convolution-Based Algorithm and First Clinical Evaluation in Patients With Acute Ischemic Stroke
The objective of this study was to develop a new method of displaying dynamic cerebral computed tomographic (CT) angiography (CTA) data sets in which the time delay to maximum enhancement (Tdelay) is displayed in a range of colors (color-coded CT angiography [cCTA]). Materials and Methods: This institutional review board-approved study included multiparametric CT data sets from 16 patients with different types of supra-aortic large vessel occlusions. Color-coded CT angiography was reconstructed from CT perfusion raw data sets. All voxel enhancement curves were fitted to f(t) = α · AIFmtt(t − Δt), w...
Source: Investigative Radiology - April 17, 2015 Category: Radiology Tags: Technical Note Source Type: research

Automated Tube Voltage Selection in Thoracoabdominal Computed Tomography at High Pitch Using a Third-Generation Dual-Source Scanner: Image Quality and Radiation Dose Performance
This study was approved by the institutional review board. Computed tomography of the body was performed using a third-generation dual-source system in 95 patients (mean body mass index, 25 kg/m2; range, 18–35 kg/m2). For 49 of these patients, all calculated tube settings and resulting dose values were recorded for each of the 12 gradual contrast weightings of the tube voltage adaptation algorithm. Spiral CT was performed for all patients with an intermediate weighting (grade 7) in a portal venous phase at 120 reference kV, 180 reference mAs, and pitch of 1.55. Objective image quality was assessed on the basis of con...
Source: Investigative Radiology - April 17, 2015 Category: Radiology Tags: Original Articles Source Type: research

In Vivo Abdominal Magnetic Resonance Elastography for the Assessment of Portal Hypertension Before and After Transjugular Intrahepatic Portosystemic Shunt Implantation
Conclusions: The observed linear correlation between spleen viscoelasticity HVPG raises the prospect of an image-based noninvasive assessment of portal pressure by magnetic resonance elastography in the follow-up of TIPS placements. (Source: Investigative Radiology)
Source: Investigative Radiology - April 17, 2015 Category: Radiology Tags: Original Articles Source Type: research

Segmentation-Based Attenuation Correction in Positron Emission Tomography/Magnetic Resonance: Erroneous Tissue Identification and Its Impact on Positron Emission Tomography Interpretation
Conclusions: Attenuation map artifacts that occur in a considerable percentage of PET/MR data sets have the potential to falsify PET quantification and visual PET interpretation. Nevertheless, on the basis of the present data, in the clinical interpretation setup, no changes in diagnosis due to μ-map artifacts may occur, especially when the μ-maps are checked for artifacts and PET/MR is read in synopsis with the NAC PET, if artifacts are present. (Source: Investigative Radiology)
Source: Investigative Radiology - April 17, 2015 Category: Radiology Tags: Original Articles Source Type: research

T1 Relaxivities of Gadolinium-Based Magnetic Resonance Contrast Agents in Human Whole Blood at 1.5, 3, and 7 T
Conclusions: This report quantifies, for the first time, T1 relaxivity for all 8 gadolinium chelates in common clinical use worldwide, at current relevant field strengths, in human whole blood at physiological temperature (37°C). The measured r1 values differ to a small degree from previously published values, where such comparisons exist, with the current r1 measurements being that most relevant to clinical practice. The macrocyclic agents, with the exception of Gd-DO3A-butrol, have slightly lower r1 values when compared with the 2 much less stable linear agents, Gd-DTPA-BMA and Gd-DTPA-BMEA. The 2 agents with hepatob...
Source: Investigative Radiology - April 17, 2015 Category: Radiology Tags: Original Articles Source Type: research

Three-Dimensional Ultrasound Molecular Imaging of Angiogenesis in Colon Cancer Using a Clinical Matrix Array Ultrasound Transducer
Conclusions: Three-dimensional USMI is feasible and highly reproducible and allows accurate assessment and monitoring of VEGFR2 expression in tumor angiogenesis in a murine model of human colon cancer. (Source: Investigative Radiology)
Source: Investigative Radiology - April 17, 2015 Category: Radiology Tags: Original Articles Source Type: research

Diffusion-Sensitized Ophthalmic Magnetic Resonance Imaging Free of Geometric Distortion at 3.0 and 7.0 T: A Feasibility Study in Healthy Subjects and Patients With Intraocular Masses
Conclusions: This work demonstrates the capability of diffusion-sensitized ms-RARE to acquire high-contrast, high–spatial resolution, distortion-free images of the eye and the orbit at 3.0 and 7.0 T. Geometric distortions that are observed for EPI-based imaging approaches even at lower field strengths are offset by fast spin-echo–based imaging techniques. The benefits of this improvement can be translated into the assessment of spatial arrangements of the eye segments and their masses with the ultimate goal to provide guidance during diagnostic treatment of ophthalmological diseases. (Source: Investigative Radiology)
Source: Investigative Radiology - April 17, 2015 Category: Radiology Tags: Original Articles Source Type: research

Krypton for Computed Tomography Lung Ventilation Imaging: Preliminary Animal Data
Conclusions: The use of krypton for lung ventilation imaging appears to be feasible and safe. Despite the use of a markedly higher concentration of krypton, enhancement is significantly worse when compared with xenon CT ventilation imaging, but sufficiently high for CT ventilation imaging studies. (Source: Investigative Radiology)
Source: Investigative Radiology - April 17, 2015 Category: Radiology Tags: Original Articles Source Type: research

Quantitative Spectral K-Edge Imaging in Preclinical Photon-Counting X-Ray Computed Tomography
Conclusions: This preclinical proof-of-concept study shows the in vivo quantification of iodine concentrations in tissues using spectral CT. Our multimodal imaging approach with spectral CT and SPECT using radiolabeled iodinated emulsions together with ICP-based quantification allows a direct comparison of all methods. Benchmarked against ICP-MS data, spectral CT in the present implementation shows a slight underestimation of organ iodine concentrations compared with SPECT but with a more narrow distribution. This slight deviation is most likely caused by experimental rather than technical issues. (Source: Investigative Radiology)
Source: Investigative Radiology - March 10, 2015 Category: Radiology Tags: Original Articles Source Type: research

Estimation of Hepatic Extracellular Volume Fraction Using Multiphasic Liver Computed Tomography for Hepatic Fibrosis Grading
Objective: The purpose of this study was to determine whether hepatic extracellular volume fractions (fECVs) measured using multiphasic liver computed tomography (CT) can be used to quantify the severity of hepatic fibrosis (HF). Materials and Methods: This retrospective study was approved by our institutional review board, and the requirement for informed consent was waived. A total of 141 patients (male-female ratio, 109:32; mean [SD] age, 59.4 [11.4] years) histologically diagnosed with HF (F0–F1 = 33 and F2–F4 = 108) underwent multiphasic liver CT. Absolute enhancements (in Hounsfield unit) of the liver par...
Source: Investigative Radiology - March 10, 2015 Category: Radiology Tags: Original Articles Source Type: research

Functional Magnetic Resonance Imaging Response of Targeted Tumor Burden and Its Impact on Survival in Patients With Hepatocellular Carcinoma
Objective: The aim of this study was to evaluate response of the targeted tumor burden by functional magnetic resonance imaging (MRI) including volumetric diffusion-weighted imaging and volumetric contrast-enhanced MRI (CE-MRI) and its impact on survival in patients with hepatocellular carcinoma treated with intra-arterial therapy (IAT). Materials and Methods: This institutional review board–approved, Health Insurance Portability and Accountability Act–compliant retrospective study included 157 hepatocellular carcinoma lesions in 97 patients (78 men and 19 women; mean age, 64 years) treated with IAT. All patien...
Source: Investigative Radiology - March 10, 2015 Category: Radiology Tags: Original Articles Source Type: research

Intermodel Agreement of Myocardial Blood Flow Estimation From Stress-Rest Myocardial Perfusion Magnetic Resonance Imaging in Patients With Coronary Artery Disease
Objectives: The aim of this study was to assess the intermodel agreement of different magnetic resonance myocardial perfusion models and evaluate their correspondence to stenosis diameter. Materials and Methods: In total, 260 myocardial segments were analyzed from rest and adenosine stress first-pass myocardial perfusion magnetic resonance images (1.5 T, 0.050 ± 0.005 mmol/kg body weight gadolinium; 122 segments in rest, 138 in stress) in 10 patients with suspected or known coronary artery disease. Signal intensity curves were calculated per myocardial segment, of which the contours were traced with QMASS MR V.7.6 (...
Source: Investigative Radiology - March 10, 2015 Category: Radiology Tags: Original Articles Source Type: research

Quantitative Relationship of Thigh Adipose Tissue With Pain, Radiographic Status, and Progression of Knee Osteoarthritis: Longitudinal Findings From the Osteoarthritis Initiative
Objective: The aim of this study was to explore the relationship of thigh subcutaneous fat (SCF) and intermuscular fat (IMF) content with knee osteoarthritis (KOA) cross-sectionally and longitudinally, using quantitative magnetic resonance imaging. Specifically, we examined relationships with frequent knee pain, various radiographic strata, and structural progression status of KOA. Materials and Methods: Subjects who showed between-knee discordance of frequent versus no pain (n = 48), osteophyte versus no radiographic KOA (n = 55), and radiographic joint space narrowing versus no joint space narrowing (n = 44) were selecte...
Source: Investigative Radiology - March 10, 2015 Category: Radiology Tags: Original Articles Source Type: research

Automated Classification of Usual Interstitial Pneumonia Using Regional Volumetric Texture Analysis in High-Resolution Computed Tomography
Conclusions: Our results are encouraging and suggest that an automated system may be useful in routine clinical practice as a diagnostic aid for identifying patients with complex lung disease such as classic UIP, obviating the need for invasive surgical lung biopsy and its associated risks. (Source: Investigative Radiology)
Source: Investigative Radiology - March 10, 2015 Category: Radiology Tags: Original Articles Source Type: research