X-ray stereopelvimetry

X-ray stereopelvimetric assessment of pelvic size during pregnancy is an important stage of examination in obstetric practice.

X-ray stereopelvimetric study includes two stages: obtaining radiographs in frontal and lateral projections, as well as taking measurements of pelvic dimensions.

Pelvic dimensions are determined by the following parameters:

1. The distance between the anteroposterior dimensions of the pelvic openings – D (diameter) – diameter
2. The distance between the transverse dimensions of the pelvic openings (anterior and posterior) – T (transverse) – diameter
3. The distance between the vertical dimensions of the pelvic openings, which is measured from the apex of the sacrum to the symphysis - V (vertical) - vertical
4. The distance between the inner edges of the pubic bones – I (internal) – internal

All measurements are taken in centimeters. X-ray stereometric examination allows you to determine the dimensions of the pelvis, which are necessary to determine the expected weight of the fetus, as well as to decide on the method of delivery.

In conclusion, X-ray stereometric assessment of pelvic dimensions is an important tool in obstetric diagnosis and provides accurate information about pelvic dimensions, which in turn can influence the choice of delivery method and the prevention of complications of pregnancy and childbirth.

An X-ray stereothereometer is a device for determining the midpoints of the cut angles of the anterior phalanges of the metacarpal bones in the transverse and vertical planes. These points are the main ones in determining the center of mass of the head and the entire body. Often such a device is called an impression taking machine.

Purpose of the X-ray stereometer:

1. determining the direction of the slope of the load line (logarithmic function of the foot) by measuring in front of the feet of the left and right feet the midpoint of the distal portion of the longitudinal axes of the second intermetatarsal bones of these feet; 2. determining the length of the left/right foot in a straight line along the back of the leg; 3. measurement at angles of 90 and 115 mm of the distance to the third toe of the right / left foot from the midline of both feet; 4. indirect determination of the length of the foot along a line passing through the angle of flexion at the subtalar joint; 5. direct determination of the height of the head edge or depression under the knees; 6. foot width measurement; 7. measuring the deviation of the basilar system and assessing orthostatic function.

Important! The provisions on measuring the shape of the foot are enshrined in GOSTs:

- 3399 – 80 (Dental products and materials) - “Dental products. Methods for determining working dimensions"; - ISO 434 – 2003 “Measurement systems (SI) - units of physical quantities and their images”; - MKS 01 - 36 – 97 “Interstate standardization system. Products. Units of physical quantities and images of units. Form of presentation."

Main errors in foot measurement: