Objectives
We evaluated the relationship between the maximum slope (MS) based on ultrafast breast DCE-MRI sequences, and the clinical parameters and routine prognostic factors of breast cancer.
...Methods
210 lesions were retrospectively evaluated: 150 malignant (30 each of luminal A invasive carcinoma, luminal B invasive carcinoma, HER2 overexpression (HER2), triple negative (TN), invasive lobular carcinoma (ILC)), and 60 benign. For each lesion, the MS was obtained with an ultrafast sequence and semi-quantitative curves were classified into three types with a conventional DCE sequence. The correlation between MS and age, body mass index (BMI), menopause, and routine prognostic factors were analyzed.
Results
A MS cut-off at 6.5%/s could discriminate benign from malignant lesions, with sensitivity and specificity of 84% and 90%, respectively, whereas analysis of semi-quantitative curves showed sensitivity and specificity of 89.3% and 55%, respectively. In multivariate analysis, MS values decreased with BMI increasing (
p
= 0.035), postmenopausal status (
p
< 0.001), and positive ER status (
p
< 0.001) and increased with tumor size (
p
< 0.001). The MS was significantly lower for the pooled luminal A + ILC group than for the pooled luminal B + HER2 + TN group featuring tumors with poorer prognoses (
p
< 0.001). With a threshold of 11%/s, the sensitivity and specificity to identify invasive carcinoma subtypes with poorer prognoses were 71% and 68%, respectively.
Conclusion
The MS allows better tumor characterization and identifies factors of poor prognosis for breast cancer.
Key Points
•
Maximum slope calculated from ultrafast breast DCE-MRI differentiates benign from malignant breast lesions better than semi-quantitative curves of conventional DCE-MRI.
•
Maximum slope calculated from ultrafast breast DCE-MRI identifies breast cancers with poor prognoses.
•
In the case of multiple lesions, the most aggressive may be identified and targeted by measuring the maximum slope.
Blood Flow Distribution in Cerebral Arteries Zarrinkoob, Laleh; Ambarki, Khalid; Wåhlin, Anders ...
Journal of cerebral blood flow and metabolism,
04/2015, Letnik:
35, Številka:
4
Journal Article
Recenzirano
Odprti dostop
High-resolution phase—contrast magnetic resonance imaging can now assess flow in proximal and distal cerebral arteries. The aim of this study was to describe how total cerebral blood flow (tCBF) is ...distributed into the vascular tree with regard to age, sex and anatomic variations. Forty-nine healthy young (mean 25 years) and 45 elderly (mean 71 years) individuals were included. Blood flow rate (BFR) in 21 intra- and extracerebral arteries was measured. Total cerebral blood flow was defined as BFR in the internal carotid plus vertebral arteries and mean cerebral perfusion as tCBF/brain volume. Carotid/vertebral distribution was 72%/28% and was not related to age, sex, or brain volume. Total cerebral blood flow (717±123 mL/min) was distributed to each side as follows: middle cerebral artery (MCA), 21%; distal MCA, 6%; anterior cerebral artery (ACA), 12%, distal ACA, 4%; ophthalmic artery, 2%; posterior cerebral artery (PCA), 8%; and 20% to basilar artery. Deviating distributions were observed in subjects with ‘fetal’ PCA. Blood flow rate in cerebral arteries decreased with increasing age (P<0.05) but not in extracerebral arteries. Mean cerebral perfusion was higher in women (women: 61±8; men: 55±6 mL/min/100 mL, P<0.001). The study describes a new method to outline the flow profile of the cerebral vascular tree, including reference values, and should be used for grading the collateral flow system.
Excessive pulsatile flow caused by aortic stiffness is thought to be a contributing factor for several cerebrovascular diseases. The main purpose of this study was to describe the dampening of the ...pulsatile flow from the proximal to the distal cerebral arteries, the effect of aging and sex, and its correlation to aortic stiffness. Forty-five healthy elderly (mean age 71 years) and 49 healthy young (mean age 25 years) were included. Phase-contrast magnetic resonance imaging was used for measuring blood flow pulsatility index and dampening factor (proximal artery pulsatility index/distal artery pulsatility index) in 21 cerebral and extra-cerebral arteries. Aortic stiffness was measured as aortic pulse wave velocity. Cerebral arterial pulsatility index increased due to aging and this was more pronounced in distal segments of cerebral arteries. There was no difference in pulsatility index between women and men. Dampening of pulsatility index was observed in all cerebral arteries in both age groups but was significantly higher in young subjects than in elderly. Pulse wave velocity was not correlated with cerebral arterial pulsatility index. The increased pulsatile flow in elderly together with reduced dampening supports the pulse wave encephalopathy theory, since it implies that a higher pulsatile flow is reaching distal arterial segments in older subjects.
Abstract This work was inspired by the observation that a majority of MR-electrical properties tomography studies are based on direct comparisons with ex vivo measurements carried out on post-mortem ...samples in the 90’s. As a result, the in vivo conductivity values obtained from MRI in the megahertz range in different types of tissues (brain, liver, tumors, muscles, etc.) found in the literature may not correspond to their ex vivo equivalent, which still serves as a reference for electromagnetic modelling. This study aims to pave the way for improving current databases since the definition of personalized electromagnetic models (e.g. for Specific Absorption Rate estimation) would benefit from better estimation. Seventeen healthy volunteers underwent MRI of both brain and thorax/abdomen using a three-dimensional ultrashort echo-time (UTE) sequence. We estimated conductivity (S/m) in several classes of macroscopic tissue using a customized reconstruction method from complex UTE images, and give general statistics for each of these regions (mean-median-standard deviation). These values are used to find possible correlations with biological parameters such as age, sex, body mass index and/or fat volume fraction, using linear regression analysis. In short, the collected in vivo values show significant deviations from the ex vivo values in conventional databases, and we show significant relationships with the latter parameters in certain organs for the first time, e.g. a decrease in brain conductivity with age.
The prevailing view on multiple sclerosis etiopathogenesis has been challenged by the suggested new entity chronic cerebrospinal venous insufficiency. To test this hypothesis, we studied 21 ...relapsing‐remitting multiple sclerosis cases and 20 healthy controls with phase‐contrast magnetic resonance imaging. In addition, in multiple sclerosis cases we performed contrast‐enhanced magnetic resonance angiography. We found no differences regarding internal jugular venous outflow, aqueductal cerebrospinal fluid flow, or the presence of internal jugular blood reflux. Three of 21 cases had internal jugular vein stenoses. In conclusion, we found no evidence confirming the suggested vascular multiple sclerosis hypothesis. ANN NEUROL 2010;68:255–259
Alterations in cerebral hemodynamics in microgravity are hypothesized to occur during spaceflight and could be linked to the Visual Impairment and Intracranial Pressure syndrome. Head-down tilt (HDT) ...is frequently used as a ground-based analog to simulate cephalad fluid shifts in microgravity; however, its effects on cerebral hemodynamics have not been well studied with MRI techniques. Here, we evaluate the effects of 1) various HDT angles on cerebral arterial and venous hemodynamics; and 2) exposure to 1% CO2 during an intermediate HDT angle (-12°) as an additional space-related environmental factor. Blood flow, cross-sectional area (CSA), and blood flow velocity were measured with phase-contrast MRI in the internal jugular veins, as well as the vertebral and internal carotid arteries. Nine healthy male subjects were measured at baseline (supine, 0°) and after 4.5 h of HDT at -6°, -12° (with and without 1% CO2), and -18°. We found a decrease in total arterial blood flow from baseline during all angles of HDT. On the venous side, CSA increased with HDT, and outflow decreased during -12° HDT (P = 0.039). Moreover, the addition of 1% CO2 to -12° HDT caused an increase in total arterial blood flow (P = 0.016) and jugular venous outflow (P < 0.001) compared with -12° HDT with ambient atmosphere. Overall, the results indicate decreased cerebral blood flow during HDT, which may have implications for microgravity-induced cerebral hemodynamic changes.
Purpose
To describe, validate, and implement a centerline processing scheme (CPS) for semiautomated segmentation and quantification in carotid siphons of healthy subjects. 4D flow MRI enables blood ...flow measurement in all major cerebral arteries with one scan. Clinical translational hurdles are time demanding postprocessing and user‐dependence induced variability during analysis.
Materials and Methods
A CPS for 4D flow data was developed to automatically separate cerebral artery trees. Flow parameters were quantified at planes along the centerline oriented perpendicular to the vessel path. At 3T, validation against 2D phase‐contrast (PC) magnetic resonance imaging (MRI) and 4D flow manual processing was performed on an intracranial flow phantom for constant flow, while pulsatile flow validation was performed in the internal carotid artery (ICA) of 10 healthy volunteers. The CPS and 4D manual processing times were measured and compared. Flow and area measurements were also demonstrated along the length of the ICA siphon.
Results
Phantom measurements for area and flow were highly correlated between the CPS and 2D measurements (area: R = 0.95, flow: R = 0.94), while in vivo waveforms were highly correlated (R = 0.93). Processing time was reduced by a factor of 4.6 compared with manual processing. Whole ICA measurements revealed a significantly decreased area in the most distal segment of the carotid siphon (P = 0.0017), with flow unchanged (P = 0.84).
Conclusion
This study exhibits fast semiautomated analysis of intracranial 4D flow MRI. Internal consistency was shown through flow conservation along the tortuous ICA siphon, which is typically difficult to assess. J. Magn. Reson. Imaging 2015;42:1458–1464.
•HASTEDL sequence reduces liver T2-weighted acquisition time at 1.5 T.•HASTEDL improves image quality and focal liver lesion contrast-to-noise ratio, notably in patients with chronic liver ...disease.•HASTEDL could be favorably embedded in abbreviated liver MRI protocols.
Acceleration of MRI acquisitions and especially of T2-weighted sequences is essential to reduce the duration of MRI examinations but also kinetic artifacts in liver imaging. The purpose of this study was to compare the acquisition time and the image quality of a single-shot fat-suppressed turbo spin-echo (TSE) T2-weighted sequence with deep learning reconstruction (HASTEDL) with that of a fat-suppressed T2-weighted BLADE TSE sequence in patients with focal liver lesions.
Ninety-five patients (52 men, 43 women; mean age: 61 ± 14 SD; age range: 28–87 years) with 42 focal liver lesions (17 hepatocellular carcinomas, 10 sarcoidosis lesions, 9 myeloma lesions, 3 liver metastases and 3 focal nodular hyperplasias) who underwent liver MRI at 1.5 T including HASTEDL and BLADE sequences were retrospectively included. Overall image quality, noise level in the liver, lesion conspicuity and sharpness of liver lesion contours were assessed by two independent readers. Liver signal-to-noise ratio (SNR) and lesion contrast-to-noise ratio (CNR) were measured and compared between the two sequences, as well as the mean duration of the sequences (Student t-test or Wilcoxon test for paired data).
Median overall quality on HASTEDL images (3; IQR: 3, 3) was significantly greater than that on BLADE images (2; IQR: 1, 3) (P < 0.001). Median noise level in the liver on HASTEDL images (0; IQR: 0, 0.5) was significantly lower than that on BLADE images (1; IQR: 1, 2) (P < 0.001). On HASTEDL images, mean liver SNR (107.3 ± 39.7 SD) and mean focal liver lesion CNR (87.0 ± 76.6 SD) were significantly greater than those on BLADE images (67.1 ± 23.8 SD, P < 0.001 and 48.6 ± 43.9 SD, P = 0.027, respectively). Acquisition time was significantly shorter with the HASTEDL sequence (18 ± 0 s; range: 18–18 s) compared to BLADE sequence (152 ± 47 SD s; range: 87–263 s) (P < 0.001).
By comparison with the BLADE sequence, HASTEDL sequence significantly reduces acquisition time while improving image quality, liver SNR and focal liver lesions CNR.
Cerebral complications related to the COVID-19 were documented by brain MRIs during the acute phase. The purpose of the present study was to describe the evolution of these neuroimaging findings (MRI ...and FDG-PET/CT) and describe the neurocognitive outcomes of these patients.
During the first wave of the COVID-19 outbreak between 1 March and 31 May 2020, 112 consecutive COVID-19 patients with neurologic manifestations underwent a brain MRI at Strasbourg University hospitals. After recovery, during follow-up, of these 112 patients, 31 (initially hospitalized in intensive care units) underwent additional imaging studies (at least one brain MRI).
Twenty-three men (74%) and eight women (26%) with a mean age of 61 years (range: 18-79) were included. Leptomeningeal enhancement, diffuse brain microhemorrhages, acute ischemic strokes, suspicion of cerebral vasculitis, and acute inflammatory demyelinating lesions were described on the initial brain MRIs. During follow-up, the evolution of the leptomeningeal enhancement was discordant, and the cerebral microhemorrhages were stable. We observed normalization of the vessel walls in all patients suspected of cerebral vasculitis. Four patients (13%) demonstrated new complications during follow-up (ischemic strokes, hypoglossal neuritis, marked increase in the white matter FLAIR hyperintensities with presumed vascular origin, and one suspected case of cerebral vasculitis). Concerning the grey matter volumetry, we observed a loss of volume of 3.2% during an average period of approximately five months. During follow-up, the more frequent FDG-PET/CT findings were hypometabolism in temporal and insular regions.
A minority of initially severe COVID-19 patients demonstrated new complications on their brain MRIs during follow-up after recovery.
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