Investigative radiology
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Investigative radiology · Dec 2020
The Limited Sensitivity of Chest Computed Tomography Relative to Reverse Transcription Polymerase Chain Reaction for Severe Acute Respiratory Syndrome Coronavirus-2 Infection: A Systematic Review on COVID-19 Diagnostics.
Several studies suggest the sensitivity of chest computed tomography (CT) is far greater than that of reverse transcription polymerase chain reaction (RT-PCR) in diagnosing COVID-19 patients, and therefore, CT should be included as a primary diagnostic tool. This systematic review aims to stratify studies as high or low risk of bias to determine the true sensitivity of CT for severe acute respiratory syndrome coronavirus-2 infection according to the unbiased (low risk) studies, a topic of particular importance given the insufficient quantity of RT-PCR kits in many countries. We focus on sensitivity as that is the chief advantage perceived of CT. ⋯ The difference between the sensitivities of CT and RT-PCR for severe acute respiratory syndrome coronavirus-2 infection is lower than previously thought, as after stratifying the studies, the true sensitivity for CT based on the unbiased studies is limited.
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Investigative radiology · Jun 2017
ReviewCritical Questions Regarding Gadolinium Deposition in the Brain and Body After Injections of the Gadolinium-Based Contrast Agents, Safety, and Clinical Recommendations in Consideration of the EMA's Pharmacovigilance and Risk Assessment Committee Recommendation for Suspension of the Marketing Authorizations for 4 Linear Agents.
For magnetic resonance, the established class of intravenous contrast media is the gadolinium-based contrast agents. In the 3 decades since initial approval, these have proven in general to be very safe for human administration. However, in 2006, a devastating late adverse reaction to administration of the less stable gadolinium-based contrast agents was identified, nephrogenic systemic fibrosis. ⋯ Cited in the report was convincing evidence of gadolinium deposition in the brain months after injection of these linear agents. Primovist/Eovist (gadoxetic acid disodium) will remain available, being used at a lower dose for liver imaging, because it meets an important diagnostic need. In addition, a formulation of Magnevist for intra-articular injection will remain available because of its very low gadolinium concentration.
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Investigative radiology · Dec 2013
ReviewCurrent technological advances in magnetic resonance with critical impact for clinical diagnosis and therapy.
The last 5 years of technological advances with major impact on clinical magnetic resonance (MR) are discussed, with greater emphasis on those that are most recent. These developments have already had a critical positive effect on clinical diagnosis and therapy and presage continued rapid improvements for the next 5 years. This review begins with a discussion of 2 topics that encompass the breadth of MR, in terms of anatomic applications, contrast media, and MR angiography. ⋯ Interventional MR is still early in its development, although well established in many centers, possessing great potential in comparison with computed tomography (CT) because of superior soft-tissue contrast, real-time multiplanar imaging guidance and monitoring, the availability of temperature mapping, and the lack of ionizing radiation. And last but not least, MR-PET is in its infancy, with the first round of clinical units installed in the past 2 years and early clinical experience showing equivalence and, in some instances, superiority to PET-CT. As with the field of MR itself, which began when CT was already an established modality, MR-PET will likely, in the next decade, become an equivalent modality to PET-CT, if not begin to supplant the latter modality.
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Investigative radiology · Apr 2010
ReviewReactive oxygen species and the pathogenesis of radiocontrast-induced nephropathy.
Experimental findings in vitro and in vivo illustrate enhanced hypoxia and the formation of reactive oxygen species (ROS) within the kidney following the administration of iodinated contrast media, which may play a role in the development of contrast media-induced nephropathy. Clinical studies indeed support this possibility, suggesting a protective effect of ROS scavenging or reduced ROS formation with the administration of N-acetyl cysteine and bicarbonate infusion, respectively. ⋯ Generated during contrast-induced renal parenchymal hypoxia, ROS may exert direct tubular and vascular endothelial injury and might further intensify renal parenchymal hypoxia by virtue of endothelial dysfunction and dysregulation of tubular transport. Preventive strategies conceivably should include inhibition of ROS generation or ROS scavenging.
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Investigative radiology · Sep 2009
ReviewImaging of the musculoskeletal system in vivo using ultra-high field magnetic resonance at 7 T.
Recently, great progress has been made in particularly in the imaging of cartilage and bone structure. Increased interest has focused on high-field (3 Tesla) imaging and more recently on ultra-high field (UHF) magnetic resonance imaging (MRI) at 7 T for in vivo imaging. Because the signal-to-noise ratio (SNR) scales linearly with field strength, a substantial increase in SNR is expected compared with lower field strengths. ⋯ Standard clinical MSK imaging relies heavily on T1, T2, and proton density weighted fast spin echo sequences. However, fast spin echo imaging has proven to be very challenging at higher fields because of very high specific absorption rates, using multiple pulses in a short time frame; thus the imaging protocols have to be adapted and gradient echo sequences may be more beneficial. Imaging of more central body parts such as the spine at 7 T is still in its infancy and dedicated coils have to be developed.