Medical Imaging Group Meeting Minutes : 4^th February 2004

Attendees : A Boston, R Herzberg, R Page, M Ibison, H Scraggs, J Sampson, S Gros,

J Norman, A Mather, G Turk, B McGuirk, D Seddon

Agenda :

Introduction to new postdocs;

Mark Ibison. X-Ray imaging. This project will be based at Daresbury with Mark

spending approximately 20% of time at Liverpool. He will begin at the start of

March. He is currently involved with the nuclear structure group at Liverpool as

an Experimental Officer

Helen Scraggs. Pet Scan. The project will be based at Liverpool for the most part.

It is looking at using highly segmented HPGe detectors for PET scans. Helen has

just completely a two year contract at TRIUMF, Canada, working on the

TIGRESS project.

Ongoing work :

G. Turk – MCNP simulations of the GREAT planar.

- Cologne data analysis ongoing. Need to optomise resolution using PSA.

Looking at deconvaluting multiple hits.

J Norman – Analysing GREAT planar data from scan at Liverpool.

- Looking at issues that have arisen from this data set such as the bad risetimes.

400ns and 250ns on the front and back.

Action - Ortec to supply 400mV/MeV on new preamps as high gain with 175mV/MeV

- Looking at image charges. Setting up program to separate it from noise.

S Gros - Clover detector work.

- simulations of electric field of planar detector in MATLAB

A Mather – GEANT simulations. Results from text file to Java to compare with MCNP

results directly.

- Comparison of real detectors

- Results to date, from 511 keV 1^st interaction being the main interaction is 70%. From the 30% that isn’t the main interaction there is uncertainty of 1cm on average.

B McGuirk – Testing exogam detectors. One dead detector and bias shutdown not

working on the other (EXOGAM07).

- CdZT looking at anode and cathode using PSA with interest in efficiency

Review of Planar design :

Discussion results from the latest SMA design from Ortec. At the moment the distance from pin to pin on the EXOGAMs is 15cm but the design for the SMARTPET planar has a distance of only 10cm. This is not enough clearance. Latest design of gantry looked at. Group is to look at designs to make sure that everyone is familiar with it and also to make sure that it makes sense. One question raised is if the distance to detectors of 200mm or

400mm is required. May need a bigger wheel to accommodate the 400mm distance is size of SMA distance is increased from 10 to 15mm.

Dates and times of meetings:

The times of the next meetings have been circulated. They will be held fortnightly in room 337 starting Thursday 12^th February at 11 am. There will also be a full day meeting in Daresbury on 18^th February to meet with Rob Lewis and his group from Melbourne, Australia. Memebers from the group in Christie’s Hospital, Manchester will also be present. The students from Australia will begin a 3 week visit at Liverpool from that date. The two students are from a clinical background.

A.O.B :

The group has also been in talks with Gary Royle. Now looking at back projection

Also interest in BGO innerball and BaF. Innerball requires a committee meeting to decide where it should go. This expected in April but could be brought forward. Problem with BaF from Nordball is that there are no electronics with it.

Rodi wishes to measure 0⁺ → 0⁺ decay from 72Ge. First excited state sits 690 keV above ground state. Want to see if decays via a conversion electron or by two back to back gamma rays. This is very exotic. Use timed neutrons at Sweden facility