Hypothermic Cooling Measured by Thermal Magnetic Resonance Imaging; Feasibility and Implications for Virtual Imaging in the Urogenital Pelvis.

Objective: To study the combination of thermal magnetic resonance imaging (MRI) and novel hypothermic cooling, via an endorectal cooling balloon (ECB), to assess the effective dispersion and temperature drop in pelvic tissue to potentially reduce inflammatory cascade in surgical applications.

Methods: Three male subjects, before undergoing robot-assisted radical prostatectomy, were cooled via an ECB, rendered MRI compatible for patient safety before ECB hypothermia. MRI studies were performed using a 3T scanner and included T2-weighted anatomic scan for the pelvic structures, followed by a temperature mapping scan.

Quantification of Regional Breast Density in Four Quadrants Using 3D MRI-A Pilot Study.

Purpose: This study presented a three-dimensional magnetic resonance (MR)-based method to separate a breast into four quadrants for quantitative measurements of the quadrant breast volume (BV) and density.

Methods: Breast MR images from 58 healthy women were studied. The breast and the fibroglandular tissue were segmented by using a computer-based algorithm.

Investigation of factors affecting hypothermic pelvic tissue cooling using bio-heat simulation based on MRI-segmented anatomic models.

This study applied a simulation method to map the temperature distribution based on magnetic resonance imaging (MRI) of individual patients, and investigated the influence of different pelvic tissue types as well as the choice of thermal property parameters on the efficiency of endorectal cooling balloon (ECB). MR images of four subjects with different prostate sizes and pelvic tissue compositions, including fatty tissue and venous plexus, were analyzed. The MR images acquired using endorectal coil provided a realistic geometry of deformed prostate that resembled the anatomy in the presence of ECB.

Impact of factors affecting the residual tumor size diagnosed by MRI following neoadjuvant chemotherapy in comparison to pathology.

Background And Objectives: To investigate accuracy of magnetic resonance imaging (MRI) for measuring residual tumor size in breast cancer patients receiving neoadjuvant chemotherapy (NAC).

Methods: Ninety-eight patients were studied. Several MRI were performed during NAC for response monitoring, and the residual tumor size was measured on last MRI after completing NAC.

Developmental changes in hippocampal shape among preadolescent children.

It is known that the largest developmental changes in the hippocampus take place during the prenatal period and during the first two years of postnatal life. Few studies have been conducted to address the normal developmental trajectory of the hippocampus during childhood. In this study shape analysis was applied to study the normal developing hippocampus in a group of 103 typically developing 6- to 10-year-old preadolescent children.

Response of bilateral breasts to the endogenous hormonal fluctuation in a menstrual cycle evaluated using 3D MRI.

The normal breast tissue responds to the fluctuation of endogenous hormones during a menstrual cycle (MC) and shows changes in breast density. The changes between left and right breasts of the same women were compared to evaluate the symmetrical response. Twenty-four healthy women were recruited in this study.

Consistency of breast density measured from the same women in four different MR scanners.

Purpose: To compare the breast volume (BV), fibroglandular tissue volume (FV), and percent density (PD) measured from breast MRI of the same women using four different MR scanners.

Methods: The study was performed in 34 healthy Asian volunteers using two 1.5T (GE and Siemens) and two 3T (GE and Philips) MR scanners.

SU-E-J-108: Quantitative Analysis of Longitudinal Cognitive Impairment Due to Radiation Therapy Based on Automatic Segmentation of Hippocampus and Subcortical Structure.

Purpose: In this study, we developed a quantitative analysis tool based on patient's longitudinal MR images to 1) measure the radiation dose received by each subcortical structure, 2) follow the change of volume and shape of each structure longitudinally. This tool provides a systematic approach to study the radiation therapy (and subsequent chemotherapy) associated with cognitive impairments.

Methods: MRI scans of one patient taken before and after radiation therapy are demonstrated in this study.

Diagnostic performance of magnetic resonance imaging for assessing tumor response in patients with HER2-negative breast cancer receiving neoadjuvant chemotherapy is associated with molecular biomarker profile.

Background: This study aimed to evaluate the influence of hormone receptor (HR) and Ki-67 proliferation markers in predicting the accuracy of magnetic resonance imaging (MRI) for measuring residual tumor size in patients with HER2-negative (HER2(-)) breast cancer receiving neoadjuvant chemotherapy (NAC).

Patients And Methods: Fifty-four women were studied. Patients received AC (doxorubicin (Adriamycin)/cyclophosphamide) and/or taxane-based regimens.

Nanometer-scale imaging by the modulation tracking method.

We developed an optical imaging method based on a feedback principle in which the specific scan pattern is adapted according to the shape of the sample. The feedback approach produces nanometer-resolved 3D images of very small and moving features in live cells in seconds. We show images of microvilli in live cultured opossum kidney cells expressing NaPi co-transporter proteins with different GFP constructs and images of cell protrusions in a collagen matrix with a resolution of about 20 nm.

Polarization ellipticity compensation in polarization second-harmonic generation microscopy without specimen rotation.

In imaging anisotropic samples with optical microscopy, a controlled, polarized light source can be used to gain molecular information of fibrous materials such as muscles and collagen fibers. However, the delivery of the polarized excitation light source in a system such as a laser scanning optical microscope often encounters the problem of the polarization ellipticity altering effects of the optical components. Using a half-wave plate and a quarter-wave plate, we demonstrate that the polarization ellipticity altering effect of the dichroic mirror in an epi-illuminated multiphoton laser scanning microscope can be corrected, and that this approach can be used to obtain polarized second-harmonic generation (SHG) images of rat tail tendon and mouse leg muscle.

Multiphoton autofluorescence and second-harmonic generation imaging of the tooth.

In this study, we used an epi-illuminated multiphoton microscope to image three main components of ex vivo human tooth. In particular, we obtained two-photon excited autofluorescence (AF) and second-harmonic generation (SHG) images of the enamel, dentin, and periodontal ligaments (PLs) and constructed three-dimensional projections of sequentially and axially acquired images. We found that the enamel has a strong two-photon AF signal, clearly revealing the structures of the enamel rods.

Effects of index-mismatch-induced spherical aberration in pump--probe microscopic image formation.

Pump--probe fluorescence microscopy has been demonstrated to be a powerful tool for obtaining three-dimensional, time-resolved information in bioimaging applications. However, the use of this technique can be complicated by the fact that the different wavelengths used to achieve pump--probe microscopy can result in wavelength-dependent spherical aberration, thus limiting the usefulness of the technique. We address this issue by investigating the effects of refractive-index-mismatch-induced spherical aberration on pump--probe image formation.