Hidex AMG Gamma Counter
| Brand | Hidex |
|---|---|
| Origin | Finland |
| Model | AMG |
| Detector | 3-inch diameter NaI(Tl) scintillation crystal |
| Energy Range | 15–2000 keV |
| Multichannel Analyzer (MCA) | 2048-channel linear |
| Energy Resolution | <30% FWHM at 27.5 keV (¹²⁵I), <30% FWHM at 39.6 keV (¹²⁹I), <9.5% FWHM at 662 keV (¹³⁷Cs) |
| Sample Capacity | 250 positions for 13 mm-diameter vials |
| Shielding | 55 mm lead equivalent overall |
| Dimensions (W×D×H) | 640 × 700 × 600 mm |
Overview
The Hidex AMG Gamma Counter is a high-sensitivity, benchtop gamma spectrometry system engineered for quantitative radionuclide detection in clinical nuclear medicine, radiopharmaceutical quality control, and research laboratories. It operates on the principle of scintillation detection: gamma photons interact with a thallium-doped sodium iodide (NaI(Tl)) crystal, generating light pulses proportional to incident photon energy. These pulses are converted to electrical signals, digitized via a 2048-channel linear multichannel analyzer (MCA), and processed to deliver energy-resolved count rates per sample. Designed specifically for routine assays involving ¹²⁵I, ⁹⁹mTc, ¹¹¹In, ⁶⁷Ga, ¹³¹I, and ¹³⁷Cs—common isotopes in PET tracer synthesis validation, GFR (glomerular filtration rate) quantification, and radioimmunoassay (RIA)—the AMG delivers reproducible, low-background measurements essential for diagnostic accuracy and regulatory compliance.
Key Features
- High-efficiency 3-inch NaI(Tl) detector with optimized light collection geometry and low-noise photomultiplier coupling, ensuring stable gain and minimal spectral drift over extended operation.
- Dual-thickness lead shielding: 55 mm average lead equivalence across the cabinet, increasing to 80 mm on the sample-access side to suppress cross-talk and ambient background—critical for low-activity clinical samples and QC of generator eluates.
- Flexible sample handling: Two interchangeable rotor configurations support high-throughput workflows—250 positions for standard 13 mm microcentrifuge tubes (e.g., RIA vials), or 78 positions for larger 28 mm serum tubes used in GFR plasma sampling.
- Energy-selective acquisition: Programmable region-of-interest (ROI) windows allow simultaneous multi-isotope counting (e.g., ⁶⁸Ga/⁶⁸Ge separation during generator elution QC) without hardware reconfiguration.
- Integrated thermal management and vibration-damped mechanical design minimize baseline noise and improve long-term stability under continuous clinical use.
Sample Compatibility & Compliance
The AMG accommodates standard borosilicate glass and polypropylene vials used in clinical radiochemistry, including those compliant with ISO 8536-4 (glass containers for pharmaceuticals) and USP <825> (hazardous drug compounding). Its energy calibration traceability supports adherence to ASTM D3648 (standard test methods for radioactivity in water) and IEC 61000-4-3 (EMC immunity for medical equipment). The system’s background count rate (<0.5 cpm in ¹²⁵I ROI) meets requirements for GLP-compliant biodistribution studies and FDA 21 CFR Part 11–ready audit trails when paired with validated software configurations.
Software & Data Management
Controlled via Hidex’s proprietary AMG Control Suite (Windows-based), the instrument provides real-time spectrum visualization, automated energy calibration using built-in ¹³³Ba and ¹⁵²Eu reference sources, and customizable assay protocols. Data export supports CSV, XML, and LIMS-compatible formats—including HL7 ADT and ORU messages for integration into hospital information systems (HIS) and radiology information systems (RIS). Audit trail functionality logs all user actions, parameter changes, and calibration events with timestamps and operator IDs—fully aligned with ALARA principles and ISO/IEC 17025 documentation requirements.
Applications
- Quantitative assessment of glomerular filtration rate (GFR) using ⁵¹Cr-EDTA or ⁹⁹mTc-DTPA plasma clearance kinetics.
- Quality control of ⁶⁸Ga-labeled peptides (e.g., DOTATATE, PSMA-11) via ⁶⁸Ge breakthrough measurement (using ⁶⁸Ge/⁶⁸Ga activity ratio calculation).
- Radioimmunoassay (RIA) and immunoradiometric assay (IRMA) quantification in endocrinology and oncology diagnostics.
- Validation of radiolabeling efficiency and purity in preclinical tracer development.
- Environmental monitoring of gamma-emitting nuclides (e.g., ¹³⁷Cs, ⁶⁰Co) in soil/water extracts following EPA Method 901.1.
FAQ
Does the AMG support automatic decay correction for multiple isotopes?
Yes—the software applies isotope-specific half-life corrections in real time during acquisition and report generation, configurable per assay protocol.
Can the system be integrated into a hospital’s PACS or RIS environment?
Yes, via DICOM-SR and HL7 interfaces; configuration requires Hidex-certified integration services and site-specific validation.
Is the NaI(Tl) detector replaceable by the user?
No—detector replacement requires factory recalibration and MCA linearity verification; Hidex recommends annual performance verification by authorized service engineers.
What is the minimum detectable activity (MDA) for ¹²⁵I in a 1-minute count?
Under standard shielding and background conditions, MDA is ≤15 Bq (0.4 pCi) at 95% confidence level, assuming 1 mL aqueous sample in a 13 mm vial.
Does the AMG comply with IEC 61000-6-2 and IEC 61000-6-3 for electromagnetic compatibility?
Yes—CE marking confirms conformity with both immunity (Part 6-2) and emission (Part 6-3) requirements for medical electrical equipment in clinical environments.
