domingo, 30 de octubre de 2016

T11

Analysis of Toshiba-manufactured CT machines:

The three models presented by Toshiba are easy enough to understand for one learned in subkects such as radioactivity and biomedical instrumentation. However, these informercials have also been designed to be understood, at least at a very basic level, by an everyday layman and every doctor interested in purchasing one.

There are three models introduced: the Aquilion One, Aquilion Prime, and the Astelion. They all share some features (as they should, since they are CT machines) but do differ in a few specs:

Aquilion One:

  • 640 slices of  0.5 nm scans: higher resolution, more detail.
  • 275 ms rotation : less time spent under x-rays
  • > 1 mSv dose for cardiac patients
  • can perform miocardial perfusion tests
  • 78 cm gantry
Aquilion Prime:
  • 80-160 slices: useful for detecting larger objects, less overall dose. 
  • 60 fps 
  • 78 cm gantry
Astelion
  • 16-32 slices
  • "eco-friendly": less power consumption
  • 75% less dose
  • Reduced gantry noise
The Aquilion One model is Toshiba's top of the line model, and it comes packed with all the toys: high resolution, fast operating times, and Toshiba's proprietary AIDR3 technology; which calculates the lowest dose required for every patient. This is a huge plus since CT scans deposit a large quantity of dose as it is. 

From here we move down to the Aquilion Prime. This model is advertised as the middle ground model and probably the one most commonly sold since it still provides a good amount of resolution and speed. At 160 slices, it falls very short of the One's 640 slice capability. However, the One is probably advertised to clinics with a lot of money or hospital emergency rooms where results are needed quickly and accurately. Prime still boasts the comfortable gantry space offered by One, but also has the advantage of depositing less radiation, due to the fewer slices it takes. Toshiba compensates this disadvantage by adding filters and processors that "offer the best quality for the lowest dose". Which is a fancy way of saying that even with less resolution, you will still get a good enough image. This model also comes with AIDR3

The Astelion servers as Toshiba's lower end model; capable of all the basic tasks, but at a lower quality. To compensate the quality, a lower price is included( I imagine) as well as many environmentally friendly features. It is only capable of 16-32 slices but consequently delivers 75% less dose. As a result of being more eco-friendly, it also provides a much quieter scan. This scanner is probably ideal for pediatrics, where minimal radioactivity is ideal, and a quieter process is less likely to frighten a child. As before, this model also includes AIDR3 technology. 

sábado, 29 de octubre de 2016

T10

Puede ver los resultados de esta tarea, trabajada en conjunto con Karim, aqui: http://instrumentacionbiomedica2kvivanco.blogspot.com.es/2016/10/t10.html

lunes, 24 de octubre de 2016

T9

1.- Elegid alguno de ellos y generad una situación adecuada para una técnica radiográfica concreta que escojáis (y particularicéis) a partir de la documentación del tema (mamografía, abdomen con contraste, extremidad superior, ...). En el blog quedara recogido el caso, el espectro generado y los parámetros que ha habido que poner para obtenerlo.

2.- También con el simulador intentad responder: ¿Se puede conseguir un haz estrecho en energías (bastante monocromático)? Probad a combinar filtros.

3.- ¿Habéis podido compara simuladores? Quizá si distintos grupos usan distinto simulador, al final se pueda hacer una puesta en común.


La situacion generada y estudiada en este caso es la de mamografia tipo Moly-Moly. Se refiere a una mamografia creada con un tubo de rayos x que contiene el anodo de molibdeno(Mo)y tambien un filtro de Mb. Se usa con frecuencia, ya que contiene el espectro ideal para los senos, en particular para los mas pequeños y menos densos. Su unica falla es que el lado superior del rango usado (de 30-35 KeV) produce demasiada penetracion, y menos contraste. Esto se deba a que los senos son todo tejido suave. Al final es de poca importancia, ya que el filtro de Mo atenua las señales no-deseadas.



La simulacion creada con un rango de 30 KeV deja apreciar los maximos donde se produce la radiacion caracteristica de este proceso, a 19.5 KeV y 17.9 KeV.

Es importante notar que el filtro usado dependera de las energias que uno quiera atenuar. Para los senos menos densos y mas pequeños es suficiente el filtro de Mo, que atenua a partir de 20 KeV:




Variando el grosor del filtro Mo, varia la intensidad de los dos picos de interes. Con un limite de grosor de aproximadamente 1 mm.

En otro simulado, pues no se como interpretar los resultados muy bien...