ROUB flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

Amniotic fluid index

Sum of the deepest vertical pocket measured in four quadrants. Normal range is 5 to 24 cm; below 5 cm is oligohydramnios and above 24 cm is polyhydramnios.

Single deepest pocket

Maximum vertical pocket free of fetal parts and cord. Less than 2 cm indicates oligohydramnios; 8 cm or greater indicates polyhydramnios. Preferred in twin gestations.

Crown-rump length dating

Between 45 and 84 mm, CRL is the most accurate first-trimester dating method. If it differs from menstrual dating by more than 5 to 7 days, the CRL-based date is used.

Nuchal translucency technique

Measured at 11+0 to 13+6 weeks with CRL 45 to 84 mm in a mid-sagittal plane, neutral neck, calipers on inner borders. Increased values raise aneuploidy and cardiac risk.

Hadlock estimated fetal weight

Uses biparietal diameter, head circumference, abdominal circumference, and femur length. Abdominal circumference is the strongest single predictor and is most affected by growth restriction.

Resistive index formula

RI equals peak systolic velocity minus end-diastolic velocity, divided by peak systolic velocity. It ranges from 0 to 1 and rises with increasing downstream vascular resistance.

Umbilical artery absent end-diastolic flow

Absent or reversed end-diastolic flow indicates severe placental insufficiency. Reversed flow carries the highest risk of stillbirth and prompts urgent fetal surveillance or delivery.

MCA peak systolic velocity

Peak systolic velocity above 1.5 multiples of the median suggests fetal anemia, as in red cell alloimmunization. Middle cerebral artery PI below the 5th centile suggests brain-sparing.

Biophysical profile scoring

Five components scored 0 or 2: fetal breathing, body movement, tone, amniotic fluid volume, and nonstress test. A score of 8 or more is generally reassuring.

Supraspinatus tear appearance

A full-thickness tear shows a focal hypoechoic gap with loss of the normal convex bursal contour. Partial tears show intrasubstance hypoechogenicity without a complete gap.

Crass position

Arm internally rotated with the hand on the ipsilateral buttock. This brings the supraspinatus tendon anteriorly for longitudinal and transverse imaging over the greater tuberosity.

Lateral epicondylitis findings

The common extensor origin at the lateral epicondyle shows hypoechoic thickening, loss of normal fibrillar pattern, and possible calcification or intrasubstance tear.

Median nerve cross-sectional area

Measured at the carpal tunnel inlet. An area greater than 10 square millimeters supports carpal tunnel syndrome; the nerve normally flattens as it passes distally.

Plantar fascia thickness

Normal plantar fascia at the calcaneal insertion measures roughly 2 to 4 mm. Thickness greater than 4 mm with hypoechogenicity supports plantar fasciitis.

Achilles tendon normal thickness

Normal anteroposterior diameter is less than 6 mm. Focal hypoechoic thickening with loss of fibrillar pattern suggests tendinopathy or partial tear.

Muscle strain grading

Grade I is strain without fiber disruption, grade II is partial tear, and grade III is complete tear with retraction. Associated hematoma appears anechoic to complex fluid.

Anisotropy artifact

Tendons and nerves appear falsely hypoechoic when the sound beam is not perpendicular to them. Correct by heel-toe angling of the transducer until the fibrillar pattern returns.

FAST exam windows

Four windows: right upper quadrant for Morison's pouch, left upper quadrant for splenorenal recess, suprapubic pelvis, and subxiphoid pericardium. Free fluid appears anechoic.

Lung sliding and pneumothorax

Present lung sliding excludes pneumothorax at that site. Absent sliding with a lung point sign is highly specific for pneumothorax; absent sliding alone is nonspecific.

B-lines

Vertical hyperechoic artifacts arising from the pleura and extending to the screen bottom. Three or more per intercostal space indicate interstitial syndrome such as pulmonary edema.

IVC collapsibility assessment

Diameter under 2 cm with more than 50 percent inspiratory collapse suggests low right atrial pressure. Over 2 cm with less than 50 percent collapse suggests elevated pressure.

Optic nerve sheath diameter

Measured 3 mm behind the globe. A diameter greater than 5 mm is a screening marker for raised intracranial pressure, though thresholds vary by study.

Transducer selection by exam

Curvilinear 2 to 5 MHz for abdomen and lung, linear 5 to 12 MHz for vascular access and superficial structures, phased array 1 to 5 MHz for cardiac imaging.

In-plane versus out-of-plane

In-plane needle guidance displays the full needle shaft and tip. Out-of-plane shows the tip as a dot, so tip position must be confirmed before advancing or injecting.

Eyeball ejection fraction

Visual estimate categories: normal 55 percent or greater, mildly reduced 45 to 54, moderately reduced 30 to 44, and severely reduced below 30 percent.

Fractional shortening formula

FS equals end-diastolic minus end-systolic internal dimension, divided by end-diastolic dimension. Normal is roughly 25 to 45 percent and correlates with ejection fraction.

Cardiac output formula

Cardiac output equals stroke volume times heart rate. Stroke volume equals left ventricular outflow tract area times outflow tract velocity-time integral.

Aortic stenosis velocity grading

Peak velocity 2.5 to 3.0 m/s is mild, 3.0 to 4.0 m/s is moderate, and above 4.0 m/s is severe. A mean gradient above 40 mmHg supports severe stenosis.

Mitral E/A ratio

Ratio of early to late diastolic mitral inflow velocities. Normally E exceeds A; reversal with E less than A suggests impaired relaxation, grade I diastolic dysfunction.

E/e-prime ratio

Ratio of mitral E velocity to tissue Doppler e-prime. A value above 14 suggests elevated left ventricular filling pressures; septal e-prime below 8 cm/s supports dysfunction.

Carotid stenosis velocities

Approximate peak systolic velocity thresholds: below 125 cm/s normal, 125 to 230 cm/s moderate stenosis, above 230 cm/s severe stenosis. Correlate with angiography.

Pericardial tamponade signs

Anechoic pericardial space with right atrial systolic collapse and right ventricular diastolic collapse. These signs suggest tamponade physiology and warrant urgent clinical correlation.

Abdominal aortic aneurysm threshold

Infrarenal aortic diameter of 3 cm or greater defines aneurysm. Diameters of 5.0 to 5.5 cm are the usual threshold for surgical or endovascular referral.