What does mapping and possible thoracentesis mean?

Question

What does mapping and possible thoracentesis mean?

Answer 1

Thoracentesis is a procedure to remove excess fluid in the space between the lungs and the chest wall. This space is called the pleural space.

Normally, the pleural space is filled with a small amount of fluid—about 4 teaspoons full. But some conditions, such as heart failure, lung infections, and tumors, can cause more fluid to build up. When this happens, it’s called a pleural effusion. A lot of extra fluid can press on the lungs, making it hard to breathe.

A phased array transducer is commonly used for mapping the pleural effusion.

A phased array ultrasound is based on an array transducer and a beamformer (mapping).  The array transducer is a cluster of miniature piezo-electric elements and the beamformer controls all the elements to “form” the ultrasound beams.  The output of the beamformer is a normal time-amplitude signal, totally equivalent to a standard A-scan.

Phased array is a better technology than conventional, mono-element ultrasound.  However, not all NDT problems are worth the investment in time and instrumentation to switch to phased array.  But most flaw detection applications are worth exploring into phased array as it’s a lot faster and simpler to perform inspections with.

A phased array beam is just like any other beam.  It has its own focal length, depth of field, beam width and divergence.

With phased array, you can focus the beam where you want, within the near-field of the overall array aperture.  When focusing close to the surface, the focal point can become very small and the depth-of-field can be pretty short. This is all part of the 'mapping' process.