1. CLRS 321: Nuclear Medicine Physics and Instrumentation I
Unit V: Introduction to Gamma Camera Lecture 3: Gamma Camera Use and Care; Non-anger gamma imaging devices
CLRS 321: Nuclear Medicine Physics and Instrumentation I
Image from Molecular Breast Imaging. Mercy Medical Center. Available at . Accessed 28 Nov 2017

2. Objectives
Regarding gamma camera systems, discuss the need for the following as well as the entity responsible for providing each:
Energy corrections
Linearity corrections
Uniformity correction map
Autotuning of PMTs
Describe gamma camera installment considerations
Discuss patient positioning considerations
Describe various imaging modes employed using gamma cameras
Describe best-practice image timing for planar imaging
Describe unconventional single-emission nuclear medicine imaging systems

3. Physical Construction
Moveable gantry supports heavy camera heads
Heads have aluminum cover and heavy collimators
PMTs are shielded with Mu metal to prevent influence of internal and external magnetic fields
Most now have tables that translate instead of gantries
Cameras typically have…
Hand control
Digitize version of a P-scope for positioning
Computer workstation for acquisition setup and processing
Collimator exchange system (may be automated)

4. Installation considerations
Stable room environment
Cool and well-ventilated
Temperature changes >9 degrees/hour may crack crystal
Best to have a uninterruptable power supply (UPS)
Has a battery that kicks in on fly
Prevents damage from power surges
Walls are transparent to gamma energy—so be careful where your cameras will be pointing
Image from General Nuclear Medicine. RadiologyInfo .org available at accessed 12 Mar 17

5. Patient positioning Just about any position.. Supine Prone Upright
Tail-on-detector (TOD)
Plantar
Palmar
Image from Nuclear Medicine (Gamma Camera). Doncaster and Bassetlaw Teaching Hospitals. NHS.uk availabe at accessed 12 Mar 17.

6. Imaging modes Static (planar) Whole-body Dynamic
Timing consideration important
Stopping according to time--more time makes for more info, but increases chances of patient movement
Stopping according to counts--when comparing views of different areas, best to be consistent with time instead of counts
Count-density—image is stopped when the desired counts per cm2 reach a certain level
Whole-body
Dynamic
SPECT (180 and 360 degree)

7. Care of Gamma Cameras Crystal very fragile
Minimize uncollimated exposure and use means to protect crystal
Lead is soft and collimators can be easily damaged by imaging bed or collimator exchanger
Crystals and PMTs degrade over time
Image from SPECT gamma camera / CT scanner / for SPECT full body / full-body tomography Discovery™ NM/CT 670 available at accessed 12 Mar 17.

8. Solid State Gamma Camera
Uses an array of many scintillation crystals (either Cadmium Zinc Telluride or Thallium Activated Cesium Iodide)
Uses semiconductor detectors(as discussed under scintillation detectors) in a pixelated array.
Each semiconductor has its own photodiode (instead of PMT)
Creates a positioning matrix rather than the positioning logic of the Anger system.

9. Solid State Gamma Camera—Digirad System
4,096 CsI(Tl) Crystals and Photodiodes
Good Efficiency
Hi Noise Potential
Very Good Resolution (2mm Intrinsic)
“Pixelated” FOV property lends itself to digitization
Consistent performance across entire FOV

10. Cadmium Zinc Telluride Crystals

11. Images from Digirad System

12. D-SPECT

13. Breast-specific Imaging
Currently referred to as molecular breast imaging (or MBI)
Uses Tc-99m Sestamibi (MiralumaTM)
Mitochondria of breast tumors have an avidity for Sestamibi
Image from MBI Cast Wider Net for Breast Cancer Diagnosis. Auntminnie.com available at accessed 12 Mar 17
Image from Molecular Breast Imaging May Increase Cancer Detection for Women with Dense Breasts. RSNA.org
Available at accessed 12 Mar 17

14. That’s Enough! (for this semester)
From Scientific American.com. Available at: Accessed November 28, 2011.