The Liver Imaging Reporting and Data System (LI-RADS) standardizes the interpretation, reporting, and data collection for imaging examinations in patients at risk for hepatocellular carcinoma (HCC). ...It assigns category codes reflecting relative probability of HCC to imaging-detected liver observations based on major and ancillary imaging features. LI-RADS also includes imaging features suggesting malignancy other than HCC. Supported and endorsed by the American College of Radiology (ACR), the system has been developed by a committee of radiologists, hepatologists, pathologists, surgeons, lexicon experts, and ACR staff, with input from the American Association for the Study of Liver Diseases and the Organ Procurement Transplantation Network/United Network for Organ Sharing. Development of LI-RADS has been based on literature review, expert opinion, rounds of testing and iteration, and feedback from users. This article summarizes and assesses the quality of evidence supporting each LI-RADS major feature for diagnosis of HCC, as well as of the LI-RADS imaging features suggesting malignancy other than HCC. Based on the evidence, recommendations are provided for or against their continued inclusion in LI-RADS.
RSNA, 2017 Online supplemental material is available for this article.
Primovist, Eovist: What to expect? Van Beers, Bernard E; Pastor, Catherine M; Hussain, Hero K
Journal of hepatology,
08/2012, Letnik:
57, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Summary Gadolinium ethoxybenzyl dimeglumine (Gd-EOB-DTPA, Primovist® in Europe and Eovist® in the USA) is a liver-specific magnetic resonance imaging contrast agent that has up to 50% hepatobiliary ...excretion in the normal liver. After intravenous injection, Gd-EOB-DTPA distributes into the vascular and extravascular spaces during the arterial, portal venous and late dynamic phases, and progressively into the hepatocytes and bile ducts during the hepatobiliary phase. The hepatocyte uptake of Gd-EOB-DTPA mainly occurs via the organic anion transporter polypeptides OATP1B1 and B3 located at the sinusoidal membrane and biliary excretion via the multidrug resistance-associated proteins MRP2 at the canalicular membrane. Because of these characteristics, Gd-EOB-DTPA behaves similarly to non-specific gadolinium chelates during the dynamic phases, and adds substantial information during the hepatobiliary phase, improving the detection and characterization of focal liver lesions and diffuse liver disease. This information is particularly relevant for the detection of metastases, and for the detection and characterization of nodular lesions in liver cirrhosis, including early hepatocellular carcinomas. Finally, GD-EOB-DTPA-enhanced magnetic resonance imaging may provide quantitative assessment regarding liver perfusion and hepatocyte function in diffuse liver diseases. The full potential of GD-EOB-DTPA-enhanced magnetic resonance imaging has to be established further. It is already clear that GD-EOB-DTPA-enhanced magnetic resonance imaging provides anatomic and functional information in the setting of focal and diffuse liver disease that is unattainable with magnetic resonance imaging enhanced with non-specific contrast agents.
To compare frequency and severity of arterial phase respiratory motion-related artifact following gadoxetate disodium and gadobenate dimeglumine in matched patients administered both contrast media ...at different times.
Institutional review board approval was obtained, with patient consent waived, for this retrospective, HIPAA-compliant study. Ninety patients underwent gadobenate dimeglumine-enhanced abdominal magnetic resonance (MR) followed by gadoxetate disodium-enhanced abdominal MR and were matched to 90 patients who were administered the same contrast media in reverse order (180 patients). Matching was based on length of time between paired examinations. Gadobenate dimeglumine dose was weight based (0.1 mmol per kilogram body weight). Gadoxetate disodium dose was typically fixed (10 or 20 mL off label). Three readers blinded to contrast agent assigned a respiratory motion-related artifact score (1 none to 5 nondiagnostic) for nonenhanced, arterial, venous, and late dynamic phases. Frequency of greater new arterial phase respiratory motion-related artifact in each within-patient pair and aggregate rate of new severe transient arterial phase respiratory motion-related artifact (scores ≤ 2, nonenhanced and venous and/or late dynamic phases; ≥ 4, arterial phase) were compared (McNemar test).
For groups 1 and 2, respectively, mean dose (gadoxetate disodium, 16.6 mL vs 16.6 mL, P = .99; gadobenate dimeglumine, 18.0 mL vs 17.8 mL, P = .77) and mean time between examinations (191 days vs 191 days, P = .99) were not significantly different between matched populations. Gadoxetate disodium was associated with significantly higher incidence of new arterial phase respiratory motion-related artifact compared with gadobenate dimeglumine (39% vs 10%, P < .0001) and of new severe transient arterial phase respiratory motion-related artifact (18% vs 2%, P < .0001) in patients administered both agents at different times.
Fixed off-label dose (10 or 20 mL) of gadoxetate disodium is associated with arterial phase respiratory motion-related artifact that is sometimes severe and occurs significantly more often than after gadobenate dimeglumine in patients who received both contrast media.
The incidence of hepatocellular carcinoma (HCC) is expected to increase in the next 2 decades, largely due to hepatitis C infection and secondary cirrhosis. HCC is being detected at an earlier stage ...owing to the implementation of screening programs. Biopsy is no longer required prior to treatment, and diagnosis of HCC is heavily dependent on imaging characteristics. The most recent recommendations by the American Association for the Study of Liver Diseases (AASLD) state that a diagnosis of HCC can be made if a mass larger than 2 cm shows typical features of HCC (hypervascularity in the arterial phase and washout in the venous phase) at contrast material-enhanced computed tomography or magnetic resonance (MR) imaging or if a mass measuring 1-2 cm shows these features at both modalities. There is an ever-increasing demand on radiologists to detect smaller tumors, when curative therapies are most effective. However, the major difficulty in imaging cirrhosis is the characterization of hypervascular nodules smaller than 2 cm, which often have nonspecific imaging characteristics. The authors present a review of the MR imaging and pathologic features of regenerative nodules and dysplastic nodules and focus on HCC in the cirrhotic liver, with particular reference to small tumors and lesions that may mimic HCC. The authors also review the sensitivity of MR imaging for the detection of these tumors and discuss the staging of HCC and the treatment options in the context of the guidelines of the AASLD and the imaging criteria required by the United Network for Organ Sharing for transplantation. MR findings following ablation and chemoembolization are also reviewed.
To determine whether acute transient dyspnea and/or arterial phase image degradation occurs more or less often after intravenous administration of gadoxetate disodium than with intravenous ...administration of gadobenate dimeglumine.
Institutional review board approval and patient consent were obtained for this prospective observational study. One hundred ninety-eight gadolinium-based contrast media administrations (99 with gadoxetate disodium 10 mL, n = 97; 8 mL, n = 1; 16 mL, n = 1 and 99 with gadobenate dimeglumine 0.1 mmol per kilogram of body weight, maximum dose, 20 mL) for hepatobiliary indications were assessed in 192 patients. Subjective patient complaints were assessed. Objective respiratory motion degradation on T1-weighted precontrast and dynamic postcontrast (arterial, venous, or late dynamic or extracellular) magnetic resonance (MR) imaging datasets were independently assessed in a randomized, blinded fashion by five readers using a five-point scale, with mean scores of 4 or greater indicating severe motion. Comparisons between agents were made by using χ(2) or Fisher exact test, where appropriate.
Significantly more patient complaints of acute transient dyspnea occurred after gadoxetate disodium administration than gadobenate dimeglumine (14% 14 of 99 vs 5% five of 99, P = .05). There were significantly more severely degraded arterial phase data sets for gadoxetate disodium than for gadobenate dimeglumine for both the general population (17% 17 of 99 vs 2% two of 99, P = .0007) and the subpopulation with cirrhosis (19% 14 of 72 vs 3% one of 37, P = .02). This effect did not extend to venous (1% one of 99 vs 2% two of 99, P > .99 overall population) or late dynamic or extracellular (2% two of 99 vs 0% zero of 99, P = .5 overall population) phases. No patient required treatment for self-limited dyspnea.
Intravenous gadoxetate disodium can result in acute self-limiting dyspnea that can have a deleterious effect on arterial phase MR image quality and occurs significantly more often than with intravenous gadobenate dimeglumine.
Even though the placenta has been known for millennia, it is still considered one of the most complex and least understood human organs. Imaging of the placenta is gaining attention due to its impact ...on fetal and maternal outcomes. MRI plays a vital role in evaluation of inconclusive cases by ultrasonography. It enables precise mapping of placental abnormalities for proper multidisciplinary planning and management. In this article we provide a comprehensive in‐depth review of the role of antenatal MR in evaluating "The Placenta." We will describe the protocols and techniques used for MRI of the placenta, review anatomy of the placenta, describe MRI features of major placental abnormalities including those related to position, depth of implantation, hemorrhage, gestational trophoblastic neoplasia, and retained products of conception and discuss the added value of MRI in the management and preoperative planning of such abnormalities.
Level of Evidence: 3
Technical Efficacy Stage: 5
J. Magn. Reson. Imaging 2019;50:1702–1717.
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