Digital Mammography X ray tests Phantoms spectra Bilateral Project (ICM-tube X-ray)

Development of a silicon detector for photon counting to be used in dual energy

radiography in the range 18-40KeV

Digital Mammography Vantages:• Better resolution • Image manipulation• Image Inversion• Identification of other tissues• Reduction of time in studies (half)

Silicon strip detector

Characteristics of SD

• Position identification

• Energy 8-30 KeV

• Spatial resolution 50-100 um

• Fast electronics

• Low noise

• Low dose

Silicon strip detector

Key system issuesFully parallel signal processing for all channels.

Only binary (yes/no) information is extracted from each strip.

Data from each channel must be stored in a local buffer for the whole measurement period.

64

bond wires

PC

computer

First prototype (1xRX64)

0.6 1.0 cm2

detector

RX64

Detector Tests

• Calibration through an internal pulse to obtain gain and noise estimation of the system

• Calibration through radiactive sources to obtain gain, noise and the absolute energy scale

• Detector test using a X ray tube at CINVESTAV and a mammograph at Hospital Juárez

• Obtain spectra with phantoms made in laboratory and an official phantom (ACR).

Calibration with radiation sources

0 2 0 4 0 6 0 8 0 1 0 0 1 2 0 1 4 0 1 6 0 1 8 0 2 0 0 2 2 0 2 4 0 2 6 0 2 8 0- 2 0 0

0

2 0 0

4 0 0

6 0 0

8 0 0

1 0 0 0

1 2 0 0

1 4 0 0

1 6 0 0

1 8 0 0

2 0 0 0

2 2 0 0

2 4 0 0

5 4 M n ( 5 , 4 k e V )3 3 , 6 8 9

1 3 3 B a ( 3 5 k e V )

1 3 3 B a ( 3 0 , 9 k e V )

1 0 9 C d ( 2 4 , 9 k e V )

1 0 9 C d ( 2 2 , 1 6 k e V )

5 7 C o ( 1 4 , 1 k e V )

5 7 C o ( 6 , 4 k e V )

2 4 3 , 0 9

2 1 4 , 6 5

1 7 7 , 3 2

1 5 7 , 5 1

4 0 , 4 7 8

1 0 0 , 7 2

d(N

) / d

(Um

bral

)

U m b r a l ( D A C )

5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0 6 0 0 6 5 02 , 5

5 , 0

7 , 5

1 0 , 0

1 2 , 5

1 5 , 0

1 7 , 5

2 0 , 0

2 2 , 5

2 5 , 0

2 7 , 5

3 0 , 0

3 2 , 5

3 5 , 0

3 7 , 5

L i n e a r R e g r e s s i o n : Y = A + B * X

A = 0 , 4 9 0 2 + / - 0 , 2 9 6 8B = 0 , 0 5 6 7 + / - 0 , 0 0 0 7

Ene

rgía

(ke

V)

U m b r a l ( m V )

Gain of 64 channels

0 , 0 5 8 0 , 0 6 0 0 , 0 6 2 0 , 0 6 4 0 , 0 6 6 0 , 0 6 80

2

4

6

8

1 0

1 2

1 4

1 6

1 8

Nú

me

ro d

e c

an

ale

s

G a n a n c i a ( m V / e l )

0 1 0 2 0 3 0 4 0 5 0 6 00 , 0 4 0

0 , 0 4 5

0 , 0 5 0

0 , 0 5 5

0 , 0 6 0

0 , 0 6 5

0 , 0 7 0

0 , 0 7 5

0 , 0 8 0

Ga

na

nci

a (

mV

/ e

l)

C a n a le s

Hospital Juárez-México

Fis. Enrique Gaona (UAM-Xochimilco)

Scanning system – 2D image

Advantages compare to 2D-systems:-reduced scatter background,-small number of the electronics channel.

scanning slit

Activities in Mexico

2004

- Caracterization and tests in hospital by A. Leyva (posdoc ALFA).

- Simulation of the system by a portuguese student (ALFA).

- Test with ACR phantom by Roxana de la Mora (Bil. Proj. Cuba)

Phantom 1 (First tests)

0 1 0 2 0 3 0 4 0 5 0 6 00 , 0

0 , 5

1 , 0

1 , 5

2 , 0

2 , 5

3 , 0

3 , 5

4 , 0

4 , 5

5 , 0

C a n a le s

Lo

ng

itud

(m

m)

1 0 , 0 0

1 5 , 0 0

2 0 , 0 0

2 5 , 0 0

3 0 , 0 0

3 5 , 0 0

4 0 , 0 0

4 5 , 0 0

5 0 , 0 0

5 5 , 0 0

6 0 , 0 0

6 5 , 0 0

7 0 , 0 0

7 5 , 0 0

8 0 , 0 0

8 5 , 0 0

9 0 , 0 0

9 5 , 0 0

1 0 0 , 0

Colimator: 250umSteps: 2Time: 3600s/stepCd-109 (22,24keV)

Semiconductor diode Image

0 10 20 30 40 50 601

2

3

4

5

6

7

8

Canales

Lon

gitu

d

(mm

)

0

43.75

87.50

131.3

175.0

218.8

262.5

306.3

350.0

Colimador: 1mmPasos: 16Tiempo: 600s/pasoCd-109 (22,24keV)

Internal image LED

60 50 40 30 20 10 06

7

8

9

10

11

12

13

0 10 20 30 40 50 60

Canales

Lo

ng

itu

d

(mm

)

0

30.00

60.00

90.00

120.0

150.0

180.0

210.0

240.0Collimator: 1mmSteps: 26Time: 3600s/stepCd-109 (22,24keV)

Structures Images with Cd-109

0 1 0 2 0 3 0 4 0 5 0 6 0

5 0

6 0

7 0

8 0

9 0

1 0 0

1 1 0

1 2 0

1 3 0

1 4 0

1 5 0

1 6 0

1 7 0

1 8 0

1 9 0

2 0 0

2 1 0

C a n a le s

Pas

os

0

3 , 0 0 0

6 , 0 0 0

9 , 0 0 0

1 2 , 0 0

1 5 , 0 0

1 8 , 0 0

2 1 , 0 0

2 4 , 0 0

Collimator: 0.5mmSteps: 26Time: 2400s/stepCd-109 (22,24keV)

ACR Phantom

The ACR phantom has structures that simulate microcalcifications of several sizes.

Internal details

BEDE X ray Tube Anode: Cu, window: Be

ICM Project

Spectrum (64 strips) phantom 1 X ray tube

0 5 1 0 1 5 2 0 2 5 3 0 3 5 4 0 4 5 5 0 5 5 6 0 6 50

1 0 0 0

2 0 0 0

3 0 0 0

4 0 0 0

5 0 0 0

6 0 0 0

7 0 0 02 0 k V + 0 . 5 m Ac o l im a d o r - 2 0 0 m

Co

nte

os

C a n a le s

ta d q

= 5 s t

a d q = 2 s

Mass profile (13) X ray tube

0 5 1 0 1 5 2 0 2 5 3 0 3 5 4 0 4 5 5 0 5 5 6 0 6 58 8 0 0

9 0 0 0

9 2 0 0

9 4 0 0

9 6 0 0

9 8 0 0

1 0 0 0 0

1 0 2 0 0

1 0 4 0 0

Co

nte

os

C a n a le s

mass 1mm

Characteristics of mammographin Hospital Juárez

• Elscint, made in Israel

• Model MAM-CH225

• X ray tube model : XRHAVA

• Range: 22-35 kV

• Automatic adjustment of current

• Anodo-filter: Mo/Mo

Detail 12 and phantom 1First results

0 5 1 0 1 5 2 0 2 5 3 0 3 5 4 0 4 5 5 0 5 5 6 0 6 53 0 0 0

3 5 0 0

4 0 0 0

4 5 0 0

5 0 0 0

5 5 0 0

6 0 0 0

Co

nte

os

C a n a le s0 6 1 2 1 8 2 4 3 0 3 6 4 2 4 8 5 4 6 0

1 0 0 0

1 0 5 0

1 1 0 0

1 1 5 0

1 2 0 0

1 2 5 0

1 3 0 0

1 3 5 0

1 4 0 0

1 4 5 0

1 5 0 0

Co

nte

os

C a n a le s

mass 2mm Phantom 1

Time:0.8s, 28kV, 90 mAs

International Collaboration

Publication

Biological Tissue (uterus)

Analysis in progress…

Activities-Ricardo

• 1(*)- Estudio de:• a) Interacción de las radiaciones con la materia.• b) Detección de las radiaciones ionizantes.• d) Detectores semiconductores de silicio• 2- Calibración 2 chips RX64.• a) Determinación de la linealidad de los

contadores.• b) Determinar Ampl DAC y Shaper DAC para el

sistema.• c) Medición de la ganancia, offset y el ruido.

Activities…

• 3- Calibración energética del sistema de detección empleando fuentes patrones radioactivas.

• 4- Obtención de imágenes de objetos en el laboratorio

• 5- Simulacion del sistema con Geant

Activities done so far• 1- Study of radiation interaction with matter

(silicon) (*)

• 2- Study simulation programs (Litrani, Geant) (*)

• 3- Measurement of gain, noise and offset through calibration pulse and radiation sources. (see report)

• 4- Programs to obtain mean and sigma of data (developed in C) (*)

* Should be in the report

Future activities…

• Most of the measurement done sofar with edge-on configuration

• Poisson test.

• Biológical tissues measurementwith both front and edge on configutations.

• Measurements with X ray tube and Mammograph.