Single-breath-hold photoacoustic computed tomography of the breast

We have developed a single-breath-hold photoacoustic computed tomography (SBH-PACT) system to reveal detailed angiographic structures in human breasts. SBH-PACT features a deep penetration depth (4 cm in vivo) with high spatial and temporal resolutions (255 µm in-plane resolution and a 10 Hz 2D frame rate). By scanning the entire breast within a single breath hold (~15 s), a volumetric image can be acquired and subsequently reconstructed utilizing 3D back-projection with negligible breathing-induced motion artifacts. SBH-PACT clearly reveals tumors by observing higher blood vessel densities associated with tumors at high spatial resolution, showing early promise for high sensitivity in radiographically dense breasts. In addition to blood vessel imaging, the high imaging speed enables dynamic studies, such as photoacoustic elastography, which identifies tumors by showing less compliance. We imaged breast cancer patients with breast sizes ranging from B cup to DD cup, and skin pigmentations ranging from light to dark. SBH-PACT identified all the tumors without resorting to ionizing radiation or exogenous contrast, posing no health risks

Clinical photoacoustic computed tomography of the human breast in vivo within a single breath hold

We have developed a single-breath-hold photoacoustic computed tomography (SBH-PACT) system to detect tumors and reveal detailed angiographic information about human breasts. SBH-PACT provides high spatial and temporal resolutions with a deep in vivo penetration depth of over 4 cm. A volumetric breast image can be acquired by scanning the breast within a single breath hold (~15 sec). We imaged a healthy female volunteer and seven breast cancer patients. SBH-PACT clearly identified all tumors by revealing higher blood vessel densities and lower compliance associated with the tumors

Warm Molecular Hydrogen Emission in Normal Edge-On Galaxies NGC 4565 and NGC 5907

We have observed warm molecular hydrogen in two nearby edge-on disk galaxies, NGC 4565 and NGC 5907, using the Spitzer high-resolution infrared spectrograph. The 0-0 S(0) 28.2 micron and 0-0 S(1) 17.0 micron pure rotational lines were detected out to 10 kpc from the center of each galaxy on both sides of the major axis, and in NGC 4565 the S(0) line was detected at r = 15 kpc on one side. This location lies beyond a steep drop in the radio continuum emission from cosmic rays in the disk. Despite indications that star formation activity decreases with radius, the H2 excitation temperature and the ratio of the H2 line and the far-IR luminosity surface densities, Sigma_L(H2}/Sigma_L(TIR}, change very little as a function of radius, even into the diffuse outer region of the disk of NGC 4565. This suggests that the source of excitation of the H2 operates over a large range of radii, and is broadly independent of the strength and relative location of UV emission from young stars. Although excitation in photodissociation regions is the most common explanation for the widespread H2 emission, cosmic ray heating or shocks cannot be ruled out. The inferred mass surface densities of warm molecular hydrogen in both edge-on galaxies differ substantially, being 4(-60) M_solar/pc^2 and 3(-50) M_solar/pc^2 at r = 10 kpc for NGC 4565 and NGC 5907, respectively. The higher values represent very unlikely point-source upper limits. The point source case is not supported by the observed emission distribution in the spectral slits. These mass surface densities cannot support the observed rotation velocities in excess of 200 km/s. Therefore, warm molecular hydrogen cannot account for dark matter in these disk galaxies, contrary to what was implied by a previous ISO study of the nearby edge-on galaxy NGC 891.Comment: Accepted for publication in the Astronomical Journal (20 pages, 17 figures, 7 tables

State Against the Migrant Child: US Government Systems and Legal Processes in Dealing with Undocumented Youth

Review of: Boehm, Deborah A., and Susan J. Terrio, editors. Illegal Encounters: The Effect of Detention and Deportation on Young People. NYU P, 2019.   DOI: 10.1353/jeu.2019.0031 &nbsp

Which imaging modality is superior for prediction of response to neoadjuvant chemotherapy in patients with triple negative breast cancer?

Background and Objectives. Triple negative breast cancer (TNBC) has been shown to be generally chemosensitive. We sought to investigate the utility of mammography (MMG), ultrasonography (US), and breast magnetic resonance imaging (MRI) in predicting residual disease following neoadjuvant chemotherapy for TNBC. Methods. We identified 148 patients with 151 Stage I–III TNBC treated with neoadjuvant chemotherapy. Residual tumor size was estimated by MMG, US, and/or MRI prior to surgical intervention and compared to the subsequent pathologic residual tumor size. Data were compared using chi-squared test. Results. Of 151 tumors, 44 (29%) did not have imaging performed prior to surgical treatment. Thirty-eight (25%) tumors underwent a pathologic complete response (pCR), while 113 (75%) had residual invasive disease. The imaging modality was accurate to within 1 cm of the final pathologic residual disease in 74 (69%) cases and within 2 cm in 94 (88%) cases. Groups were similar with regards to patient age, race, tumor size and grade, and clinical stage (). Accuracy to within 1 cm was the highest for US (83%) and the lowest for MMG (56%) (). Conclusions. Breast US and MRI were more accurate than MMG in predicting residual tumor size following neoadjuvant chemotherapy in patients with TNBC. None of the imaging modalities were predictive of a pCR

A Dual-Modality Photoacoustic and Ultrasound Imaging System for Noninvasive Sentinel Lymph Node Detection: Preliminary Clinical Results

Sentinel lymph node biopsy (SLNB) has emerged as an accurate, less invasive alternative to axillary lymph node dissection, and it has rapidly become the standard of care for patients with clinically node-negative breast cancer. The sentinel lymph node (SLN) hypothesis states that the pathological status of the axilla can be accurately predicted by determining the status of the first (i.e., sentinel) lymph nodes that drain from the primary tumor. Physicians use radio-labeled sulfur colloid and/or methylene blue dye to identify the SLN, which is most likely to contain metastatic cancer cells. However, the surgical procedure causes morbidity and associated expenses. To overcome these limitations, we developed a dual-modality photoacoustic and ultrasound imaging system to noninvasively detect SLNs based on the accumulation of methylene blue dye. Ultimately, we aim to guide percutaneous needle biopsies and provide a minimally invasive method for axillary staging of breast cancer. The system consists of a tunable dye laser pumped by a Nd:YAG laser, a commercial ultrasound imaging system (Philips iU22), and a multichannel data acquisition system which displays co-registered photoacoustic and ultrasound images in real-time. Our clinical results demonstrate that real-time photoacoustic imaging can provide sensitive and specific detection of methylene blue dye in vivo. While preliminary studies have shown that in vivo detection of SLNs by using co-registered photoacoustic and ultrasound imaging is feasible, further investigation is needed to demonstrate robust SLN detection

Moving Forward in Remembering a Truthful Past

Review of: Arato, Rona. The Ship to Nowhere: On Board the Exodus. Second Story, 2016. Kacer, Kathy, and Jordana Lebowitz. To Look a Nazi in the Eye: A Teen’s Account of a War Criminal Trial. Second Story, 2017.     DOI: 10.1353/jeu.2018.0013 &nbsp