Purpose:
To create an automatic workflow for evaluation of thresholds of restricted diffusion, based on Apparent Diffusion Coefficient (ADC) values in multiparametric (mp)MRI of the prostate. To ...investigate the association of these volumes with biopsy Gleason Score (GS).
Methods:
Patients with prostate cancer, imaged on 3T Discovery MR750 (GE, Waukesha, WI) magnet were selected from departmental database based on the presence of mpMRI exam. All subsequent analyses were performed using Java plugins in MIM (MIM, Cleveland, Ohio). Prostate, peripheral zone (PZ) and urethra were contoured manually for each patient. The procedure defines three volumes on ADC in PZ, related to high (<T1 µm2/s), medium (<T2 µm2/s), and low risk (<T3 µm2/s), where T1<T2<T3. The thresholds for each patient were set 200 µm2/s apart, i.e. T2=T1+200 µm2/s and T3=T1+400 µm2/s. The thresholds were offset by 100 µm2/s for the transition zone (TZ). Pixels with ADC<400 µm2/s and within the urethra are excluded from the analysis. The correlations between (i) ADC volume sizes; and (ii) the fractions of the volumes from the prostate volume (ADC/Prostate) and GS were investigated with Spearman correlation.
Results:
mpMRIs from 139 the analysis. The correlations between (i) ADC volume sizes; and (ii) the fractions of the volumes from the prostate volume (ADC/Prostate) and GS were investigated with Spearman correlation.
Results:
mpMRIs from 139 selected patients with mpMRI acquired between May, 2012 and February, 2016, were analyzed. Six values for T1 were investigated starting from 750 to 950 µm2/s with step of 50 µm2/s. All correlations between ADC volumes and ADC/Prostate volumes and GS were significant. The following thresholds for PZ/TZ: 950/700, 1100/900 and 1200/1100 performed the best for high, mid and low risk. The correlation coefficients of of ADC high and ADC high/Prostate were 0.45 and 0.469 with p-values <<0.00001.
Conclusion:
To the best of our knowledge, this is the first report which associates volumes of low diffusion and GS.
Purpose:
To determine whether blood oxygenation level dependent (BOLD) MRI signal measured in prostate cancer patients, in addition to quantitative diffusion and perfusion parameters from ...multiparametric (mp)MRI exams, can help discriminate aggressive and/or radioresistant lesions.
Methods:
Several ongoing clinical trials in our institution require mpMRI exam to determine eligibility (presence of identifiable tumor lesion on mpMRI) and prostate volumes for dose escalation. Upon consent, patients undergo fiducial markers placement and a T2*-weighted imaging at the time of CT sim to facilitate the fusion. In a retrospective analysis eleven clinical trial patients were identified who had undergone mpMRI on GE 3T magnet, followed by T2*-weighted imaging (time-period mean±SD = 48±20 days) using a consistent protocol (gradient echo, TR/TE=30/11.8ms, flip angle=12, matrix=256×256×75, voxel size=1.25×1.25×2.5mm). ROIs for prostate tumor lesions were automatically determined using ADC threshold ≤1200 µm2/s. Although the MR protocol was not intended for BOLD analysis, we utilized the T2*-weighted signal normalized to that in nearby muscle; likewise, T2-weighted lesion signal was normalized to muscle, following rigid registration of the T2 to T2* images. The ratio of these normalized signals, T2*/T2, is a measure of BOLD effect in the prostate tumors. Perfusion parameters (Ktrans, ve, kep) were also calculated.
Results:
T2*/T2 (mean±SE) was found to be substantially lower for Gleason score (GS) 8&9 (0.82±0.04) compared to GS 7 (1.08±0.07). A k-means cluster analysis of T2*/T2 versus kep = Ktrans/ve revealed two distinct clusters, one with higher T2*/T2 and lower kep, containing only GS 7 lesions, and another with lower T2*/T2 and higher kep, associated with tumor aggressiveness. This latter cluster contained all GS 8&9 lesions, as well as some GS 7.
Conclusion:
BOLD MRI, in addition to ADC and kep, may play a role (perhaps orthogonal to Gleason score) in identifying prostate lesions that would benefit from more aggressive radiotherapy.
The inclusive cross section for top-quark pair production measured by the CMS experiment in proton-proton collisions at a center-of-mass energy of 7 TeV is compared to the QCD prediction at ...next-to-next-to-leading order with various parton distribution functions to determine the top-quark pole mass, mtpole, or the strong coupling constant, alphaS. With the parton distribution function set NNPDF2.3, a pole mass of 176.7+3.8-3.4 GeV is obtained when constraining alphaS at the scale of the Z boson mass, mZ, to the current world average. Alternatively, by constraining mtpole to the latest average from direct mass measurements, a value of alphaS(mZ) = 0.1151+0.0033-0.0032 is extracted. This is the first determination of alphaS using events from top-quark production.
The mass of the top quark is measured using a sample of ttbar candidate events with at least six jets in the final state. The sample is selected from data collected with the CMS detector in pp ...collisions at sqrt(s)=7 TeV in 2011 and corresponds to an integrated luminosity of 3.54 inverse femtobarns. The mass is reconstructed for each event employing a kinematic fit of the jets to a ttbar hypothesis. The top-quark mass is measured to be 173.49 +/- 0.69 (stat.) +/- 1.21 (syst.) GeV. A combination with previously published measurements in other decay modes by CMS yields a mass of 173.54 +/- 0.33 (stat.) +/- 0.96 (syst.) GeV.
The Upsilon(1S), Upsilon(2S), and Upsilon(3S) production cross sections are measured using a data sample corresponding to an integrated luminosity of 35.8 +/-1.4 inverse picobarns of proton-proton ...collisions at sqrt(s) = 7 TeV, collected with the CMS detector at the LHC. The Upsilon resonances are identified through their decays to dimuons. Integrated over the Upsilon transverse momentum range ptUpsilon < 50\GeV and rapidity range abs(yUpsilon) < 2.4, and assuming unpolarized Upsilon production, the products of the Upsilon production cross sections and dimuon branching fractions are sigma(pp to Upsilon(1S) X) B(Upsilon(1S) to mu+ mu-) = (8.55 +/- 0.05 +0.56/-0.50 +/- 0.34) nb, sigma(pp to Upsilon(2S) X) B(Upsilon(2S) to mu+ mu-) = (2.21 +/- 0.03 +0.16/-0.14 +/- 0.09) nb, sigma(pp to Upsilon(3S) X) B(Upsilon(3S) to mu+ mu-) = (1.11 +/- 0.02 +0.10/-0.08 +/- 0.04) nb, where the first uncertainty is statistical, the second is systematic, and the third is from the uncertainty in the integrated luminosity. The differential cross sections in bins of transverse momentum and rapidity, and the cross section ratios are presented. Cross section measurements performed within a restricted muon kinematic range and not corrected for acceptance are also provided. These latter measurements are independent of Upsilon polarization assumptions. The results are compared to theoretical predictions and previous measurements.
Results on two-particle angular correlations for charged particles emitted in pPb collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV are presented. The analysis uses two million ...collisions collected with the CMS detector at the LHC. The correlations are studied over a broad range of pseudorapidity, eta, and full azimuth, phi, as a function of charged particle multiplicity and particle transverse momentum, pt. In high-multiplicity events, a long-range (2
Results are reported from a search for the anomalous production of highly boosted Z bosons with large transverse momentum and decaying to the dimuon final state. Such Z bosons may be produced in the ...decays of new heavy particles. The search uses pp collision data at sqrt(s) = 7 TeV, corresponding to an integrated luminosity of 5.0 inverse femtobarns recorded with the CMS detector. The shape of the observed transverse-momentum distribution of Z bosons is consistent with standard-model expectations. Constraints are obtained on models predicting the production of excited quarks decaying via electroweak processes. For excited-quark decays involving only standard-model gauge bosons and coupling strengths, masses of excited quarks below 1.94 TeV are excluded at the 95% confidence level, assuming a compositeness scale equal to the excited-quark mass. For excited-quark production via novel contact interactions, masses below 2.22 TeV are excluded, even if the excited quarks do not couple to gluons.
Results are presented from a search for a narrow, spin-2 resonance decaying into a pair of Z bosons, with one Z-boson decaying into leptons (e+e- or mu+mu-) and the other into jets. An example of ...such a resonance is the Kaluza--Klein graviton, GKK, predicted in Randall--Sundrum models. The analysis is based on a 4.9 inverse femtobarn sample of proton-proton collisions at a center-of-mass energy of 7 TeV, collected with the CMS detector at the LHC. Kinematic and topological properties, including decay angular distributions as a novel feature of the analysis, are used to discriminate between signal and background. No evidence for a resonance is observed, and upper limits on the production cross sections times branching fractions are set. In two models that predict Z-boson spin correlations in graviton decays, graviton masses are excluded lower than a value which varies between 610 and 945 GeV, depending on the model and the strength of the graviton couplings.
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