Effects of neonatal lung abnormalities on parenchymal R * estimates.

Infants admitted to the neonatal intensive care unit (NICU) often suffer from multifaceted pulmonary morbidities that are not well understood. Ultrashort echo time (UTE) magnetic resonance imaging (MRI) is a promising technique for pulmonary imaging in this population without requiring exposure to ionizing radiation. The aims of this study were to investigate the effect of neonatal pulmonary disease on R * and tissue density and to utilize numerical simulations to evaluate the effect of different alveolar structures on predicted R *.

Transverse relaxation rates of pulmonary dissolved-phase Hyperpolarized Xe as a biomarker of lung injury in idiopathic pulmonary fibrosis.

Purpose: The MR properties (chemical shifts and decay rates) of dissolved-phase hyperpolarized (HP) Xe are confounded by the large magnetic field inhomogeneity present in the lung. This work improves measurements of these properties using a model-based image reconstruction to characterize the decay rates of dissolved-phase HP Xe in healthy subjects and patients with idiopathic pulmonary fibrosis (IPF).

Methods: Whole-lung MRS and 3D radial MRI with four gradient echoes were performed after inhalation of HP Xe in healthy subjects and patients with IPF.

Characterization of and tissue density in the human lung: Application to neonatal imaging in the intensive care unit.

Purpose: Novel demonstration of and tissue density estimation in infant lungs using 3D ultrashort echo time MRI. Differences between adult and neonates with no clinical indication of lung pathology is explored, as well as relationships between parameter estimates and gravitationally dependent position and lung inflation state. This provides a tool for probing physiologic processes that may be relevant to pulmonary disease and progression in newborns.

Technical Note: Model-based magnification/minification correction of patient size surrogates extracted from CT localizers.

Purpose: Patient size-specific dose estimate (SSDE) calculations require knowledge of a patient's size. Errors in patient size propagate through SSDE calculations. AAPM Reports 204 and 220 recommend that a magnification correction be applied to patient size surrogates extracted from CT localizer radiographs.

A method to extract image noise level from patient images in CT.

Purpose: Image quality in computed tomography (CT) is usually not quantified in real time from patient scans. Rather, phantom scans are employed to measure the contrast, noise, and spatial resolution properties of a given system. This approach, however, is not ideal because many factors are difficult to represent using phantoms like variations in patient size, composition, and position within the gantry.

Tracking Patterns of Nonadherence to Prescribed CT Protocol Parameters.

Purpose: Quantification of the frequency, understanding the motivation, and documentation of the changes made by CT technologists at scan time are important components of monitoring a quality CT workflow.

Methods: CT scan acquisition data were collected from one CT scanner for a period of 1 year. The data included all relevant acquisition parameters needed to define the technical side of a CT protocol.

Diversity of the trifunctional histidine biosynthesis gene (his) in cereal Phaeosphaeria species.

Phaeosphaeria species are important causal agents of Stagonospora leaf blotch diseases in cereals. In this study, the nucleotide sequence and deduced polypeptide of the trifunctional histidine biosynthesis gene (his) are used to investigate the phylogenetic relationships and provide molecular identification among cereal Phaeosphaeria species. The full-length sequences of the his gene were obtained by PCR amplification and compared among cereal Phaeosphaeria species.

RNA polymerase II gene (RPB2) encoding the second largest protein subunit in Phaeosphaeria nodorum and P. avenaria.

A 5586 bp sequence (accession no. DQ278491), which includes the RNA polymerase II gene (RPB2) encoding the second largest protein subunit (RPB2), was obtained from the wheat biotype Phaeosphaeria nodorum (PN-w) by PCR amplification. The 3841 bp full length RPB2 gene contains two exons and a 52 bp intron, and encodes a complete 1262 amino acid protein.

A New Biotype of Phaeosphaeria sp. of Uncertain Affinity Causing Stagonospora Leaf Blotch Disease in Cereals in Poland.

A new Phaeosphaeria sp. biotype was isolated from winter ryes in Poland during 1995. Two isolates, Sn23-1 and Sn48-1, were obtained from diseased leaves of cvs.

Sequence diversity of beta-tubulin (tubA) gene in Phaeosphaeria nodorum and P. avenaria.

Full-length coding sequences of the beta-tubulin gene (tubA) were PCR-amplified and sequenced from 42 Phaeosphaeria isolates, including 16 P. nodorum and 23 P. avenaria species from cereals, two Polish isolates from rye (Secale cereale L.