nuchal thickness scan

(noun)

A sonographic prenatal screening scan (ultrasound) to help identify any high risks of chromosomal defects, including Down's Syndrome in a fetus, particularly for older women who have higher risks of such pregnancies.

Related Terms

Examples of nuchal thickness scan in the following topics:

  • Prenatal Diagnostic Tests

    • At about 6 weeks of pregnancy, an ultrasound dating scan may be offered to help confirm the gestational age of the embryo and check if a single or twin pregnancy exists, but such a scan is unable to detect common abnormalities.
    • Around weeks 10–11, a nuchal thickness scan (NT) may be offered, which can be combined with blood tests that correlate with chromosomal abnormalities.

  • Leaf Structure, Function, and Adaptation

    • The epidermis is usually one cell layer thick.
    • However, in plants that grow in very hot or very cold conditions, the epidermis may be several layers thick to protect against excessive water loss from transpiration.
    • Many aquatic plants have leaves with wide lamina that can float on the surface of the water; a thick waxy cuticle on the leaf surface that repels water.
    • (b) (bottom) These leaf layers are clearly visible in the scanning electron micrograph.
    • This scanning electron micrograph shows xylem and phloem in the leaf vascular bundle.

  • Rhizaria

    • The shells of dead radiolarians sink to the ocean floor, where they may accumulate in 100 meter-thick depths.
    • This fossilized radiolarian shell was imaged using a scanning electron microscope.

  • Stem Anatomy

    • Tracheids are xylem cells with thick secondary cell walls that are lignified.
    • Collenchyma cell walls are uneven in thickness, as seen in this light micrograph.
    • The (a) colorized scanning-electron micrograph shows a closed stoma of a dicot.
    • The central pith (greenish-blue, in the center) and peripheral cortex (narrow zone 3–5 cells thick, just inside the epidermis) are composed of parenchyma cells.

  • Meditation

    • Modern scientific techniques and brain-scan instruments have been used to see what happens in the bodies of people when they meditate, and how their bodies and brains change after meditating regularly.
    • A recent study found a significant cortical thickness increase in individuals who underwent a brief eight-week training program, and that this increase was coupled with a significant reduction of several psychological indices related to worry, anxiety, and depression.

  • Cathode Ray Tube, TV and Computer Monitors, and the Oscilloscope

    • As a matter of safety, the face is typically made of thick lead glass so as to be highly shatter-resistant and to block most X-ray emissions, particularly if the CRT is used in a consumer product.
    • In television sets and computer monitors, the entire front area of the tube is scanned repetitively and systematically in a fixed pattern called a raster .

  • Male Reproductive Anatomy

    • The glands make a solution that is thick, yellowish, and alkaline.
    • Human sperm, visualized using scanning electron microscopy, have a flagellum, neck, and head.

  • Blood-Brain Barrier

    • It was not until the introduction of the scanning electron microscope that the actual membrane could be observed and proven to exist.
    • This barrier also includes a thick basement membrane and astrocyte cell projections called astrocytic feet (forming the thin barrier called the glia limitans) that surround the endothelial cells of the BBB, providing biochemical support to those cells.