1. – The clinical utility of ultrafast cardiocentric 3D SPECT novel semi-conductor scanner technology –
Berry Allen PhD 31 August 2013

3. Nuclear Medicine (Molecular Imaging) Principles
Functional clinical information derived from observing radiopharmaceutical distribution / kinetics at a molecular level.
Diagnostic data is provided by observing the pharmaceutical kinetics
In vivo studies undertaken on a Gamma Camera / PET scanner.
Radionuclide is ‘passive’; enabling the pharmaceutical to be localised.
99mTechnetium is the most frequently used radioisotope
140 kev γ photon
6.02 hour physical half-life

4. Gamma Camera Principles
The gamma camera detector consists of: - collimator - scintillation crystal (Tl NaI) - an array of photomultiplier tubes - electronic system for detection and measurement of gamma energies
The emission of a single gamma ray is a very small
scale nuclear phenomenon
It is the role of the gamma camera detector to amplify
this photon into an electric signal that can be detected
By exploiting a large number of detected photons and resulting electric signals, it is possible to map the radioactive nuclei responsible for the emission of gamma rays

5. Conventional (Gamma) camera configuration

6. Semi conductor (CZT) detectors
Cadmium Zinc Telluride (Cd ZnTe), is a semiconductor material that directly
converts X-rays or Gamma-rays to electrons
times increase in count rate sensitivity compared to NaI – shorter imaging times
Capable of processing more than one million photons per second per square mm
Spectroscopic resolution of CZT outperforms most other detectors
True 3D volumetric acquisition
No reconstruction resolution recovery or collimator recovery algorithms / processing required
530c mm spatial resolution (pin hole collimation)
5% – 6% Energy resolution (NaI crystal ~ %)

7. Stationary semi conductor Cardiac scanners
D-SPECT scanner

8. Garcia et al JNM Vol. 52 • No. 2 • February 2011
GE D530c Stationary Data (Gantry) Acquisition
Single Photon Emission Computed Tomography SPECT camera design with standard parallel hole collimators is more than 50 years old
‘Conventional’ SPECT - inefficient as only small part of the
available crystal area is used to image the heart (Fig A)
Novel dedicated scanner - all available detectors are constrained
to imaging just the cardiac field of view (Fig B)
Garcia et al JNM Vol. 52 • No. 2 • February 2011

9. Garcia et al JNM Vol. 52 • No. 2 • February 2011
GE D530c Stationary Data (Gantry) Acquisition
Indirect radiation conversion with
conventional SPECT detector
(Fig A)
Direct radiation conversion
with CZT detector
(Fig B)
Garcia et al JNM Vol. 52 • No. 2 • February 2011

10. Module / Detector/ Triplet Assembly 1 Triplet with 3 Detectors
1 CZT Module
4 Modules in a Detector

11. D530c Stationary Data Gantry Acquisition
Consisting of an array of 19 pinhole collimators,each with 4 solid-state CZT pixilated modules
All 19 detectors simultaneously image the heart
Nine of the pinhole detectors are oriented perpendicular
to the patient’s long axis and 5 are angulated above
and 5 below the axis for a true 3-dimensional acquisition
geometry

13. Pathophysiology of Coronary Artery Disease

14. Pathophysiology of Coronary Artery Disease

15. 530c CZT / NaI Comparison 99mTc based tracer
530 CZT ‘Standard’ NaI
530c CZT / NaI Comparison 99mTc based tracer
530 CZT
Patient:
67 yr female
weight: 50 kg
Indication:
Atypical chest pain
Presurgical assessment
Procedure:
Low dose stress (pharmacologic)
6 min scan
NaI
20 min scan

16. Dual energy 201Thallium – 99mTc cardiac imaging The ‘Ideal‘ option
This technique is not possible on standard gamma camera due to poor photon energies separation characteristics
~ 65% injected radioactivity dose reduction
The procedure is now a LOW dose study.
Was a HIGH dose procedure
Immediate imaging
60% reduction in imaging time relative to standard gamma camera
1 hour proceed versus 5 hours on standard gamma camera

17. Pre angioplasty stress 201-thallium stress test
Figure 1. Exercise thallium stress test images before angioplasty exhibiting significant reversible ischemia in the septal, anterior, and apical walls. Rows A and B are short-axis views of poststress and resting imaging, respectively. Rows C and D are vertical long-axis views of poststress and resting imaging, respectively. Rows E and F are horizontal long-axis views of poststress and resting imaging, respectively.
Klein J J et al. Circulation 2004;109:e191-e193

18. Dual Isotope 201Tl 5 Min Stress / 99mTc Rest MIBI 3 Min

19. Dual Isotope LAD Territory 201Tl Pharmacologic / 99mTc Rest
Patient:
67 yr male
weight: 79 kg
Indication:
CABG 2006
PCI to LAD
No chest pain / SOB
MVA LOC Angiography : Normal grafts
Procedure:
Low dose 201Tl / 99mTc-MIBI

20. Average Dose Reduction
99mTc Activities (MBq)
Dual Detector
Sodium Iodide
CZT
Reduction
Rest First
400
220
-45%
Stress
900
590
201Tl Activities (MBq)
Dual Detector
Sodium Iodide
CZT
Reduction
Stress
150 56
-63%
Redistribution 50 15
-70%

21. Standard SPECT vs D530c CZT MPI August 2011-April 2013
Dual isotope
Tc Studies only

23. Ultrafast Parathyroid 3D CZT SPECT
‘Standard’ tracer administered radioactivities – 10 minute scan
Does however allow for lower injected activities - ~ % reduction
Dual isotope 201Thallium / 99mTc (Thyroid) protocol possible
Markedly improved study sensitivity and specificity over ‘standard’ NaI technology
Excellent for the claustrophobic patient

24. Clinical features of parathyroid adenomas
Characteristics %
Gender
Female 90
Male 10
Age (median 54.5 yrs)
20-40 9
40-70 83
>70 8
Localisation
Right superior 6
Left superior 2
Right inferior 48
Left inferior 40
Intrathyroidal
Bilateral inferior
Smj 2006, vol:27

25. Parathyroid

26. Ultrafast parathyroid SPECT

27. Ultrafast parathyroid SPECT

28. Ultrafast parathyroid SPECT
Patient:
60 yr female
weight: 65 kg
Indication:
1º Hyperparthyroidism
Decreased Bone density
Elevated Ca2+ and PTH

29. Ultrafast parathyroid 3D SPECT
Patient:
60 yr female
weight: 65 kg
Indication:
1º Hyperparthyroidism
Decreased Bone density
Elevated Ca++ and PTH
Procedure:
‘Small patient’
6 minute scan

30. Parathyroid scan – ‘Conventional scanner’
Patient:
55 yr female
weight: 75 kg
Indication:
1º Hyperparthyroidism
Elevated Ca++ and PTH
Previous Parathyroid (other institution) scan NAD
Procedure:
‘Small patient’
8 minute scan

31. Ultrafast parathyroid 3D SPECT
Patient:
55 yr female
weight: 75 kg
Indication:
1º Hyperparthyroidism
Elevated Ca++ and PTH
Previous Parathyroid (other institution) scan NAD
Procedure:
‘Small patient’
8 minute scan
‘Standard’ MPI filter
Customised filter

32. Ultrafast Bone 3D SPECT Patient: 20 yr female weight: 60 kg
Indication:
Signs of Mandibular
condyle hyperplasia

33. The Sentinel Node Concept

34. Breast sentinel node 3D SPECT
Patient:
39 yr female
weight: 65 kg
Indication:
Left Breast cancer ?

35. Breast sentinel node 3D SPECT
Patient:
39 yr female
weight: 65 kg
Indication:
Left Breast cancer

37. Discussion What has been the impact of this innovative technology?
Significantly reduced patient radiation burden
Markedly improved image quality
‘Real time’ 3D volumetric acquisition and reconstruction
Significantly reduced scanning times
Myocardial perfusion and ‘Other’ structures imaging proving to be fast,
demonstrating excellent image resolution, and clinical improved sensitivity
Improved patient journey and comfort
As production costs decline, the technology will become more ‘mainstream

38. White light
Ultraviolet light

39. Thank you