A vérnyomás változása befolyásolhatja az áramlástani jellemzőket, és ezáltal a vesék hemodinamikáját is. Fél vesés állapotban ez a hatás még jelentősebb lehet. A veseartéria környezetének in vivo mérhetetlen áramlástani jellemzőit numerikus áramlástani szimulációval hatékonyan lehet vizsgálni. A kutatás elsődleges célja annak bizonyítása volt, hogy a magas vérnyomás és az izolált szisztolés hypertonia változásokat eredményez a veseartéria áramlástani jellemzőiben, amelyek fél vesés esetben jelentősebbek. Módszer: Egy véletlenszerűen kiválasztott betegcsoport aorta-veseartéria jobb és bal oldali elágazási szögeit mértük retrospektív módon, in vivo. A veseartéria áramlástani jellemzőinek mérésére egy numerikus áramlástani szimulációsorozatot végeztünk egészséges és fél vesés modelleken. A vérnyomást először fokozatosan növeltük 120/80 Hgmm értékről 200/90 Hgmm értékig. Ezt követően az izolált szisztolés hypertonia esetét szimuláltuk a diasztolés vérnyomást fokozatosan csökkentve 200/50 Hgmm értékig. A szimuláció kimenő paraméterei a nyomás, turbulens kinetikus energia, sebesség és térfogatáram értékei voltak a veseartériák kilépő keresztmetszetén. Eredmény: A veseartéria-elágazási szögek átlaga a bal oldalon 78°, a jobb oldalon 66° volt. A szimuláció eredményei azt mutatták, hogy a magas vérnyomás és az izolált szisztolés hypertonia következetesen változtatják a veseartéria áramlástani jellemzőit, fél vesés esetben nagyobb mértékben. Konklúziók: A vesét károsíthatja a nagyobb nyomás, a turbulencianövekedés atherosclerosishoz vezethet a veseartéria elágazásánál. Ezek a jellemzők nagyobb mértékben változnak fél vesés állapotban, így ez veszélyesebb a vesére nézve. Az áramlási sebesség és térfogatáram értékei azonban nem függenek szignifikánsan a fél vesés állapottól.

Based on a prior university patent, the authors developed a novel type of bioimpedance-based test method to noninvasively detect nonalcoholic fatty liver disease (NAFLD). The development of a new potential NAFLD diagnostic procedure may help to understand the underlying mechanisms between NAFLD and severe liver diseases with a painless and easy-to-use paraclinical examination method, including the additional function to detect even the earlier stages of liver disease. The aim of this study is to present new results and the experiences gathered in relation to NAFLD progress during animal model and human clinical trials.

Background and Aim: Since the initial release of the World Wide Web, the capabilities of web browsers have grown from presenting formatted documents to running complex programs, such as 3D game engines. The medical imaging community started to adopt technologies that came with the fifth major version of the HyperText Markup Language (HTML5). It led to the creation of various web-based radiological applications such as cornerstone.js or BrainBrowser. BrainBrowser supports both 3D and 2D rendering of neuroimaging data. However, it cannot run important image processing algorithms, such as brain extraction and linear registration, which are essential in most neuroimaging workflows. The most commonly used library that supports these algorithms is the FMRIB Software Library (FSL). We aim to build a web-based cross-platform neuroimaging platform that combines data visualization with image processing.Methods: We built our system as an extension of BrainBrowser. We developed WebMRI in Java Script and designed the user interface using HTML, CSS, and Bootstrap. We used Emscripten to port the brain extraction and linear registration tools of FSL to the web. Results: We built WebMRI, a fully web-based extensible neuroimaging platform that combines the visualization capabilities of BrainBrowser with the brain extraction and linear registration tools of FSL by porting them from C++ to WebAssembly. We extended BrainBrowser with a plugin system that makes it easy to bring other processing algorithms into the platform. We released the WebMRI source code on Github: https://github.com/wpmed92/WebMRI.Conclusions: We developed and released WebMRI, a web-based cross-platform open-source neuroimaging platform.

To study the effect of non-ionic contrast media on anticoagulated and non-anticoagulated human whole blood samples, calorimetric measurements were performed. The anticoagulated plasma showed the greatest fall in the total ΔH after Iodixanol treatment. The plasma-free erythrocytes revealed a pronounced shift in the Tmax and a decrease in the ΔH of hemoglobin and transferrin. The total ΔH of Iodixanol treatment showed the highest decline, while Iomeprol and Iobitridol had fewer adverse effects. Similarly, the non-anticoagulated samples revealed a decrease both in the Tmax and the ΔH of albumin and immunoglobulin-specific transitions. The total ΔH showed that Iodixanol had more influence on the serum. The serum-free erythrocyte samples resulted in a significant drop in the Tmax of erythrocyte and transferrin (~5–6 °C). The ΔH of deconvolved hemoglobin and transferrin decreased considerably; however, the ΔH of albumin increased. Surprisingly, compared to Iomeprol and Iobitridol treatments, the total ΔH of Iodixanol was less pronounced in the non-anticoagulated erythrocyte samples. In sum, each non-ionic contrast medium affected the thermal stability of anticoagulated and non-anticoagulated erythrocyte proteins. Interestingly, Iodixanol treatment caused more significant effects. These findings suggest that conformational changes in blood components can occur, which can potentially lead to the increased prevalence of cardiovascular dysfunctions and blood clotting.

Introduction: In the circulatory system, the vessel branching angle may have hemodynamic consequences. We hypothesized that there is a hemodynamically optimal range for the renal artery’s branching angle. Methods: Data on the posttransplant kinetics of estimated glomerular filtration rate (eGFR) were analyzed according to the donor and implant sides (right-to-right and left-to-right position; n = 46). The renal artery branching angle from the aorta of a randomly selected population was measured using an X-ray angiogram (n = 44). Computational fluid dynamics simulation was used to elucidate the hemodynamic effects of angulation. Results and Discussion: Renal transplant patients receiving a right donor kidney to the right side showed faster adaptation and higher eGFR values than those receiving a left donor kidney to the right side (eGFR: 65 ± 7 vs. 56 ± 6 mL/min/1.73 m2; p < 0.01). The average branching angle on the left side was 78° and that on the right side was 66°. Simulation results showed that the pressure, volume flow, and velocity were relatively constant between 58° and 88°, indicating that this range is optimal for the kidneys. The turbulent kinetic energy does not change significantly between 58° and 78°. Conclusion: The results suggest that there is an optimal range for the renal artery’s branching angle from the aorta where hemodynamic vulnerability caused by the degree of angulation is the lowest, which should be considered during kidney transplantations.

AbstractBackground and AimSince the initial release of the World Wide Web, the capabilities of web browsers have grown from presenting formatted documents to running complex programs, such as 3D game engines. The medical imaging community started to adopt technologies that came with the fifth major version of the HyperText Markup Language (HTML5). It led to the creation of various web-based radiological applications such as cornerstone.js or BrainBrowser. BrainBrowser supports both 3D and 2D rendering of neuroimaging data. However, it cannot run important image processing algorithms, such as brain extraction and linear registration, which are essential in most neuroimaging workflows. The most commonly used library that supports these algorithms is the FMRIB Software Library (FSL). We aim to build a web-based cross-platform neuroimaging platform that combines data visualization with image processing.MethodsWe built our system as an extension of BrainBrowser. We developed WebMRI in JavaScript and designed the user interface using HTML, CSS, and Bootstrap. We used Emscripten to port the brain extraction and linear registration tools of FSL to the web.ResultsWe built WebMRI, a fully web-based extensible neuroimaging platform that combines the visualization capabilities of BrainBrowser with the brain extraction and linear registration tools of FSL by porting them from C++ to WebAssembly. We extended BrainBrowser with a plugin system that makes it easy to bring other processing algorithms into the platform. We released the WebMRI source code on Github: https://github.com/wpmed92/WebMRI.ConclusionsWe developed and released WebMRI, a web-based cross-platform open-source neuroimaging platform.

COVID-19 infection may lead to serious complications, e.g., need for mechanical ventilation or death in some cases. A retrospective analysis of patients referred to our COVID Emergency Department, indiscriminately, was performed. A routine lab analysis measured amino acids in plasma and urine of patients. Data of surviving and deceased patients and those requiring or not requiring mechanical ventilation were compared, and logistic regression analyses have been performed. Deceased patients were older, had higher blood glucose, potassium, AST, LDH, troponin, d-dimer, hsCRP, procalcitonin, interleukin-6 levels (p < 0.05 for all). They had lower plasma serine, glycine, threonine, tryptophan levels (p < 0.01), higher tyrosine and phenylalanine levels (p < 0.05), and higher fractional excretion of arginine, methionine, and proline (p < 0.05) than survivors. In a regression model, age, severity score of COVID-pneumonia, plasma levels of threonine and phenylalanine were predictors of in-hospital mortality. There was a difference in ventilated vs. non-ventilated patients in CT-scores, glucose, and renal function (p < 0.001). Using logistic regression, CT-score, troponin, plasma level, and fractional excretion of glycine were predictors of ventilation. Plasma levels and renal excretion of certain amino acids are associated with the outcome of COVID-19 infection beside other parameters such as the CT-score or age.

Currently the most widespread way of reporting in radiology is dictation mainly due to performance benefits. The output of this method is plain text, which varies in style (structure, nomenclature, abbreviations, etc.) and content between doctors even when reporting the exact same case. Templated radiology provides a structure for reporting and aims to help in generating more unified reports. We propose a web-based system for creating and using radiological structured reporting templates.We developed our software based on web technologies. We wrote the system with modular design in mind. We have separate libraries for the different functionalities: a rendering library which renders the templates based on a schema, an editor library which handles template creation, and an evaluator library, which parses, and executes our custom domain specific language, FormScript, which enables dynamic behavior in our templates. We also developed a Single Page Application to create, browse, use and share templating reports. The backend of the application is powered by Firebase from Google.We deployed our system at a publicly accessible domain at https://app.radiosheets.com.

The effects of Iodixanol contrast medium were studied on human blood samples with differential scanning calorimetry (DSC). Measurements on anticoagulated and non-anticoagulated samples revealed that the components of the plasma and serum turned into a thermodynamically less stable state in the presence of Iodixanol. The thermal parameters of the main transition peak changed in the same way for both the plasma and serum erythrocyte samples in the presence of Iodixanol. The T-max1 values of the main thermal transition were not dramatically different (similar to 70 degrees C). The T-max2 value of the peak at higher temperature range (similar to 80-85 degrees C) shifted considerably (by 3.97-4.89 degrees C) towards the lower temperature range, while the Delta H value showed a significant drop (similar to 61%) in the presence of higher concentration of Iodixanol. The results suggest that Iodixanol in blood samples can induce specific changes in the structure of blood components by altering the fundamental thermodynamic properties of the underlying biological system.

Összefoglaló. Bevezetés: A stroke kezelésének lehetőségei az utóbbi években jelentősen megváltoztak: a thrombolysis után bevezetésre került a mechanikus thrombectomia, és a terápiás időablak is jelentősen kitágult az utóbbi évek nagy multicentrikus tanulmányai alapján. Ezek a lehetőségek új igényeket fogalmaztak meg a képalkotó diagnosztikával szemben: az ischaemia okozta morfológiai elváltozások mellett az artériás és a kollaterális rendszer állapotát, valamint bizonyos esetekben az agy szöveti perfúzióját is szükséges meghatározni. Ezeket a komplex kiértékelési feladatokat ma már mesterségesintelligencia-algoritmusok támogathatják, melyek a kiértékelést pár perc alatt elvégezve segítenek a terápiás döntés kialakításában. Célkitűzés: A Dél- és a Nyugat-dunántúli régióban hat intézmény részvételével egy dedikált stroke teleradiológiai hálózat kialakítása. Módszer: A stroke-CT-kiértékelő szoftver és a képkommunikáció integrációja, a vizsgálati protokollok technikai paramétereinek egységesítése, a kiértékelési eredmények teleradiológiai megjelenítése valósult meg a hálózat kialakítása során. Eredmények: A hálózat egységesítette nemcsak a stroke-CT-protokollok beállításait, de beutalási és értékelési szempontjait is. A stroke-CT-kiértékelések és a mechanikus thrombectomiák száma is emelkedett az elmúlt egy évben. Következtetés: A dedikált teleradiológiai stroke-hálózat segítségével optimalizálni kívánjuk a régió stroke-ellátását: egyrészt lehetőleg ne maradjanak ellátatlanul a thrombectomiából valószínűleg profitáló betegek, másrészt ne terheljük az ellátórendszert olyan esetekkel, melyekről a teljes dokumentáció ismeretében derül ki, hogy nem javasolt a beavatkozás. Orv Hetil. 2021; 162(17): 668–675. Summary. Introduction: The possibilities of cerebral stroke management have changed substantially during the last few years. Following a few multicentric studies, mechanical thrombectomy became an established method besides thrombolysis. In addition, the therapeutic window for both methods is much wider now than before. These changes described above demanded more information of CT morphological changes due to ischemia, but the condition and functionality of the arterial and collateral system, and occasionally tissue perfusion performance should also be characterized. Recently, evaluation of different computer tomographic (CT) measurements can be done using artificial intelligence based methods, which perform data analysis in a few minutes. Objective: To establish a dedicated stroke teleradiology network with artificial intelligence based image analysis in Western and Southern Transdanubia in Hungary that involves six partner institutes. Method: Integration of automated image analysis with teleradiology software was established, and the technical parameters of examination protocols were unified. Results of stroke CT image analysis became accessible through the teleradiology network. Results: The daily use of integrated central image analysis and image communication had a positive impact on referrals and therapeutic evaluation of stroke cases. The number of image processing and mechanical thrombectomy increased during the last year. Conclusion: With the help of the dedicated teleradiology stroke network, we want to optimize the stroke care in the region: on the one hand, patients who are likely to benefit from thrombectomy should not be left unattended, on the other, the health care system should not be burdened with cases, when intervention is not recommended having the complete clinical data accessed. Orv Hetil. 2021; 162(17): 668–675.

This systematic review aims to test the hypothesis that microbleeds detected by MRI are common and show a characteristic pattern in cerebral fat embolism (CFE). Eighty-four papers involving 140 CFE patients were eligible for this review based on a systematic literature search up to 31 January 2020. An additional case was added from hospital records. Patient data were individually scrutinised to extract epidemiological, clinical and imaging variables. Characteristic CFE microbleed pattern resembling a “walnut kernel” was defined as punctuate hypointensities of monotonous size, diffusely located in the subcortical white matter, the internal capsule and the corpus callosum, with mostly spared corona radiata and non-subcortical centrum semiovale, detected by susceptibility- or T2* weighted imaging. The presence rate of this pattern and other, previously described MRI markers of CFE such as the starfield pattern and further diffusion abnormalities were recorded and statistically compared. The presence rate of microbleeds of any pattern, the “walnut kernel microbleed pattern”, diffusion abnormality of any pattern, the starfield pattern, and cytotoxic edema in the corpus callosum was found to be 98.11%, 89.74%, 97.64%, 68.5%, and 77.27% respectively. The presence rate between the walnut kernel and the starfield pattern was significantly ( p < 0.05) different. Microbleeds are common and mostly occur in a characteristic pattern resembling a “walnut kernel” in the CFE MRI literature. Microbleeds of this pattern in SWI or T2* MRI, along with the starfield pattern in diffusion imaging appear to be the most important imaging markers of CFE and may aid the diagnosis in clinically equivocal cases.

Purpose: A former rodent study showed that cerebral traumatic microbleeds (TMBs) may temporarily become invisible shortly after injury when detected by susceptibility weighted imaging (SWI). The present study aims to validate this phenomenon in human SWI. Methods: In this retrospective study, 46 traumatic brain injury (TBI) patients in various forms of severity were included and willingly complied with our strict selection criteria. Clinical parameters potentially affecting TMB count, Rotterdam and Marshall CT score, Mayo Clinic Classification, contusion number, and total volume were registered. The precise time between trauma and MRI [5 h 19 min to 141 h 54 min, including SWI and fluid-attenuated inversion recovery (FLAIR)] was individually recorded; TMB and FLAIR lesion counts were assessed. Four groups were created based on elapsed time between the trauma and MRI: 0–24, 24–48, 48–72, and >72 h. Kruskal–Wallis, ANOVA, Chi-square, and Fisher’s exact tests were used to reveal differences among the groups within clinical and imaging parameters; statistical power was calculated retrospectively for each comparison. Results: The Kruskal–Wallis ANOVA with Conover post hoc analysis showed significant (p = 0.01; 1−β > 0.9) median TMB number differences in the subacute period: 0–24 h = 4.00 (n = 11); 24–48 h = 1 (n = 14); 48–72 h = 1 (n = 11); and 72 h ≤ 7.5 (n = 10). Neither clinical parameters nor FLAIR lesions depicted significant differences among the groups. Conclusion: Our results demonstrate that TMBs on SWI MRI may temporarily become less detectable at 24–72 h following TBI.

Összefoglaló. Bevezetés: A stroke kezelésének lehetőségei az utóbbi években jelentősen megváltoztak: a thrombolysis után bevezetésre került a mechanikus thrombectomia, és a terápiás időablak is jelentősen kitágult az utóbbi évek nagy multicentrikus tanulmányai alapján. Ezek a lehetőségek új igényeket fogalmaztak meg a képalkotó diagnosztikával szemben: az ischaemia okozta morfológiai elváltozások mellett az artériás és a kollaterális rendszer állapotát, valamint bizonyos esetekben az agy szöveti perfúzióját is szükséges meghatározni. Ezeket a komplex kiértékelési feladatokat ma már mesterségesintelligencia-algoritmusok támogathatják, melyek a kiértékelést pár perc alatt elvégezve segítenek a terápiás döntés kialakításában. Célkitűzés: A Dél- és a Nyugat-dunántúli régióban hat intézmény részvételével egy dedikált stroke teleradiológiai hálózat kialakítása. Módszer: A stroke-CT-kiértékelő szoftver és a képkommunikáció integrációja, a vizsgálati protokollok technikai paramétereinek egységesítése, a kiértékelési eredmények teleradiológiai megjelenítése valósult meg a hálózat kialakítása során. Eredmények: A hálózat egységesítette nemcsak a stroke-CT-protokollok beállításait, de beutalási és értékelési szempontjait is. A stroke-CT-kiértékelések és a mechanikus thrombectomiák száma is emelkedett az elmúlt egy évben. Következtetés: A dedikált teleradiológiai stroke-hálózat segítségével optimalizálni kívánjuk a régió stroke-ellátását: egyrészt lehetőleg ne maradjanak ellátatlanul a thrombectomiából valószínűleg profitáló betegek, másrészt ne terheljük az ellátórendszert olyan esetekkel, melyekről a teljes dokumentáció ismeretében derül ki, hogy nem javasolt a beavatkozás. Orv Hetil. 2021; 162(17): 668-675.SUMMARY:INTRODUCTION:The possibilities of cerebral stroke management have changed substantially during the last few years. Following a few multicentric studies, mechanical thrombectomy became an established method besides thrombolysis. In addition, the therapeutic window for both methods is much wider now than before. These changes described above demanded more information of CT morphological changes due to ischemia, but the condition and functionality of the arterial and collateral system, and occasionally tissue perfusion performance should also be characterized. Recently, evaluation of different computer tomographic (CT) measurements can be done using artificial intelligence based methods, which perform data analysis in a few minutes.OBJECTIVE:To establish a dedicated stroke teleradiology network with artificial intelligence based image analysis in Western and Southern Transdanubia in Hungary that involves six partner institutes.METHOD:Integration of automated image analysis with teleradiology software was established, and the technical parameters of examination protocols were unified. Results of stroke CT image analysis became accessible through the teleradiology network.RESULTS:The daily use of integrated central image analysis and image communication had a positive impact on referrals and therapeutic evaluation of stroke cases. The number of image processing and mechanical thrombectomy increased during the last year.CONCLUSION:With the help of the dedicated teleradiology stroke network, we want to optimize the stroke care in the region: on the one hand, patients who are likely to benefit from thrombectomy should not be left unattended, on the other, the health care system should not be burdened with cases, when intervention is not recommended having the complete clinical data accessed. Orv Hetil. 2021; 162(17): 668-675.

BACKGROUND:In Pompe disease, resistance exercise could be an effective treatment to delay motor function impairment, however, the acute effects of this exercise modality are unclear.METHODS:In a prospective cohort study, we compared responses to a single bout of resistance exercise by serum markers of muscle damage and quantitative muscle magnetic resonance imaging (MRI) in patients (n=12) and age- and gender-matched healthy controls (n=12). Participants performed 50 maximal effort concentric knee flexions on a dynamometer.RESULTS:Twenty-four hours after exercise, levels of serum creatine kinase, lactate dehydrogenase and myoglobin increased in controls. In contrast, only myoglobin level increased in patients. All elevated serum markers declined by 48 hours after exercise in both groups. Mild soreness developed at 24 hours, which disappeared at 48 hours in both groups. In controls, MRI R2* relaxation rate reduced immediately and 24 hours after exercise, indicating increased water content and muscle perfusion. In patients, exercise had no effect on R2* values. The resistance exercise did not induce acute strength deficit in patients, rather, patients increased their strength by 24 hours. When serum marker changes were normalized to the magnitude of knee flexor tension developed during exercise, lactate dehydrogenase response was greater in patients.CONCLUSIONS:Late-onset Pompe disease did not exacerbate exercise-induced muscle damage, however, lactate dehydrogenase may be monitored to screen high responders during high intensity resistance exercise interventions.

This study aims to test computer-aided diagnosis (CAD) for thyroid nodules in clinical ultrasonography (US) practice with a focus towards identifying thyroid entities associated with CAD system misdiagnoses. Two-hundred patients referred to thyroid US were prospectively enrolled. An experienced radiologist evaluated the thyroid nodules and saved axial images for further offline blinded analysis using a commercially available CAD system. To represent clinical practice, not only true nodules, but mimicking lesions were also included. Fine needle aspiration biopsy (FNAB) was performed according to present guidelines. US features and thyroid entities significantly associated with CAD system misdiagnosis were identified along with the diagnostic accuracy of the radiologist and the CAD system. Diagnostic specificity regarding the radiologist was significantly (p < 0.05) higher than when compared with the CAD system (88.1% vs. 40.5%) while no significant difference was found in the sensitivity (88.6% vs. 80%). Focal inhomogeneities and true nodules in thyroiditis, nodules with coarse calcification and inspissated colloid cystic nodules were significantly (p < 0.05) associated with CAD system misdiagnosis as false-positives. The commercially available CAD system is promising when used to exclude thyroid malignancies, however, it currently may not be able to reduce unnecessary FNABs, mainly due to the false-positive diagnoses of nodule mimicking lesions.

The screening chest X ray was performed by a 51 years old men without cardiac history, which has shown a mass-like density at the left side of the heart.Echocardiography and cardiac MRI were performed.The global left ventricular function was reduced, Hypokinesis and transmural LGE with MVO were confirmed in the anterior, septal and inferior apical segments and in the apex.Furthermore large (7*6*6 cm) cystic mass was shown in the anterior intreventricular sulcus.The SI in the cyst was high on the T2w images, but in it there were two small hypointens masses.The SI in the cyst on the LGE images was a little bit higher then in the left ventricle.The small masses were not enhaced.Because of the patient was asymptomatic, elective coronary CTA was planned for the differential diagnosis of the cystic mass, and for the diagnosis of coronary artery disease.Unfortunately 3 weeks later the patient had a typical chest pain and STE in the anterior ECG leads.Urgent coronary angiography was performed.Subtotal occlusion In the middle segment of the LAD and large coronary aneurysm were confirmed.Urgent coronary bypass surgery was performed.After the resection of the coronary aneurysm the LAD and the D1 were grafted with SV.Coronary aneurysm and trombus were confirmed by histology.After 1 year the patient is asymptomatic.Coronary artery aneurysms are detected in 1.2-4.9% of patients undergoing coronary angiography and are reportedly present in 1.4% of post-mortem examinations.They occur in males more frequently than females.The most affected coronary artery is the RCA.Our case highlights the potential problems associated with coronary aneurysms.Coronary aneurysm usually remains asymptomatic however they can be complicated by myocardial infarction.

Magnetic resonance imaging using respiratory navigation technique can be the number one diagnostic method determining operability of large-sized abdominal tumors of dogs. This technique eliminates motion artifacts and makes possible the visualization of the origin and extent of the tumor and of the possible abdominal metastases.

Previously, we reported human traumatic brain injury cases demonstrating acute to subacute microbleed appearance changes in susceptibility-weighted imaging (SWI-magnetic resonance imaging [MRI]). This study aims to confirm and characterize such temporal microbleed appearance alterations in an experimental model. To elicit microbleed formation, brains of male Sprague Dawley rats were pierced in a depth of 4 mm, in a parasagittal position bilaterally using 159 mu m and 474 mu m needles, without the injection of autologous blood or any agent. Rats underwent 4.7 T MRI immediately, then at multiple time points until 125 h. Volumes of hypointensities consistent with microbleeds in SWI were measured using an intensity threshold-based approach. Microbleed volumes across time points were compared using repeated measures analysis of variance. Microbleeds were assessed by Prussian blue histology at different time points. Hypointensity volumes referring to microbleeds were significantly decreased (corrected p < 0.05) at 24 h compared with the immediate or the 125 h time points. By visual inspection, microbleeds were similarly detectable at the immediate and 125 h imaging but were decreased in extent or completely absent at 24 h or 48 h. Histology confirmed the presence of microbleeds at all time points and in all animals. This study confirmed a general temporary reduction in visibility of microbleeds in the acute phase in SWI. Such short-term appearance dynamics of microbleeds should be considered when using SWI as a diagnostic tool for microbleeds in traumatic brain injury and various diseases.

PurposeDelayed ferumoxytol enhancement on T1‐weighted images appears visually similar to gadoteridol enhancement. The purpose of this study was to quantitatively compare ferumoxytol T1 enhancement to gadoteridol enhancement with an objective, semi‐automated method.Methods206 sets of post‐gadoteridol and 24 h post‐ferumoxytol T1‐weighted scans from 58 high grade glioma patients were analyzed (9 pre‐chemoradiation, 111 < 90 days post‐chemoradiation, 21 > 90 days post‐chemoradiation, 65 post‐bevacizumab scans). Enhancement volumes and signal intensities normalized to normal appearing tissue proximal to enhancement were calculated with a semi‐automated method. Enhancement cube root volumes (D) and signal intensities (SI) were compared between the 2 contrast agents, and relative difference of D and SI were compared in different treatment groups with multivariate analysis. Within patient differences in D and SI before and after treatment with bevacizumab or steroid were assessed in 26 patients in each treatment group.ResultsWhen compared to gadoteridol, ferumoxytol D was 13.83% smaller and SI was 7.24% lower (P < 0.0001). The relative differences in D and SI between the 2 contrast agents were not significantly different between treatment groups (P > 0.05). Relative difference in D and SI did not change significantly in response to bevacizumab (P = 0.5234 and P = 0.2442, respectively) or to steroid (P = 0.3774, P = 0.0741) in the within patient comparison.ConclusionThe correlation between the 2 contrast agents’ enhancement size and signal intensity and their similar behavior in response to therapy suggest that ferumoxytol can be used for revealing enhancement in high grade glioma patients. Magn Reson Med 80:224–230, 2018. © 2017 International Society for Magnetic Resonance in Medicine.