Hatef Mehrabian

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We hypothesized that sex hormones may affect motility disorders because these diseases occur more often in women than in men, and symptoms often occur or worsen after ovulation. Luteinizing hormone (LH) is predominantly secreted by the anterior pituitary midway through the menstrual cycle; it results in the development of the corpus luteum. LH levels also(More)
Assessing tumor response to therapy is a crucial step in personalized treatments. Pharmacokinetic (PK) modeling provides quantitative information about tumor perfusion and vascular permeability that are associated with prognostic factors. A fundamental step in most PK analyses is calculating the signal that is generated in the tumor vasculature. This signal(More)
Understanding brain hemodynamics as well as the coupling between microvascular hemodynamics and neural activity is important in pathophysiology of cerebral microvasculature. When local increases in neuronal activity occur, the blood volume changes in the surrounding brain vasculature. Dynamic contrast enhanced imaging (DCE) is a powerful technique that(More)
Pharmacokinetic (PK) modeling of tumors provides information about perfusion and vascular permeability of tumors. Identifying arterial input function (AIF) is crucial in PK modeling using dynamic contrast enhanced (DCE)-MRI. An adaptive complex independent component analysis method is developed to identify and separate AIF from complex DCE-MRI data. The(More)
A fully automatic ICA based data driven technique which incorporates additional a priori information from physiological modeling of the cerebral microcirculation (gamma variate model) is developed for the separation of arteries and veins in contrast-enhanced studies of the cerebral microvasculature. A dynamic data set of 50 images taken by a two-photon(More)
PURPOSE The purpose of this work was to determine the predictive value of chemical exchange saturation transfer (CEST) metrics in brain metastases treated with stereotactic radiosurgery (SRS). METHODS CEST spectra at a radiofrequency power of 0.52 µT were collected on a 3 Tesla (T) magnetic resonance imaging from 25 patients at three time points:(More)
Dynamic contrast enhanced MRI combined with Pharmacokinetic (PK) modeling of prostate tissue provides information about its microenvironment and vascular permeability. A fundamental step in PK analysis is measuring the intravascular contrast agent concentration or the arterial input function (AIF). In this study a method is introduced to calculate the(More)
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