Macroradigraphy

Macroradigraphy 

It is the production of the enlarged image by x ray magnification. The divergence of the beam from a small source is used to magnify the image geometrically.

Requirements:

Ø  Fine focus of 0.1mm2 or less is ideal but 0.3mm2 focus can be considered as well

Ø  Short exposure time

Principles:

The degree of magnification obtained by the macroradiography depends on the ration of focus- film distance to focus-object distance.

Magnification: size of image/size of object

Magnification: focus-film distance/focus-object distance

If the object is midway between the focus and the film the magnification on the radiograph is  twice then the orginal one i.e *2.

Uses:

Ø  In dacrocystography

Ø  In sailography

Ø  In skeletal views i.e carpal and tarsal bone particularly

Ø  Investigation of temporal bones

Ø  Investigation on neonatal heart disease

Microfocal macroradiography:

If higher digree of magnification i.e >*2  are required,microfocal tube with focal spot of between 10µ and 25µ is used which enables magnification up to *100 and *4 relatively.

Microradiography:

Microradiography is a term use for the radiographic examination of microscopic structures, e.g  specimens of breast following surgery.

A focal spot of less than 100µ is used and can demonstrate calcification as small as 2µ.

Preapared by:

Sarose Bhandari