By Vvon Engineering Team | Published | Updated
Match QA phantoms to the exact system and tests, establish the required baselines before clinical use, and add tools when new capabilities are commissioned.
Nuclear medicine RFQ checklist (TXT)
Choose a QA set from the measurements needed for the installed equipment and planned clinical service. Review overlapping functions and available shared resources with the physicist before cutting items by price.
This guide addresses nuclear-medicine QA equipment for the department’s agreed checks. Preclinical PET/CT phantoms require a separate scanner-geometry and research-use discussion. Related reading: Choosing preclinical PET/CT QA phantoms in Bangladesh: match the test before the model.
This guide connects Leeds Test Objects products with their documented functions. The required programme and acceptance criteria come from the exact system, applicable standards and responsible medical physicist.
The descriptions below are functional: what test the phantom supports and when you would run it. Several of these phantoms are supplied in more than one configuration, so confirm inserts, fill options and accessories at quotation stage rather than assuming from the model name.
| Phantom | Documented or relevant measurement | Programme planning |
|---|---|---|
| Gamma Flood Phantom | Uniformity of detector response across the field of view, integral and differential | Confirm configuration, method and interval in the approved QA programme |
| Gamma Resolution Phantom | Spatial resolution, scored visually from a bar pattern | Confirm configuration, method and interval in the approved QA programme |
| Gamma Distortion Phantom | Spatial linearity and geometric distortion from an orthogonal pattern | Confirm configuration, method and interval in the approved QA programme |
| SPECT IQ | Tomographic image quality: contrast, uniformity and resolution in reconstructed slices | Confirm configuration, method and interval in the approved QA programme |
| PET IQ Phantom | PET image quality, including recovery of hot and cold structures | Confirm configuration, method and interval in the approved QA programme |
| PET CT MRI Cubes | Spatial registration and alignment between PET, CT and MRI datasets | Confirm configuration, method and interval in the approved QA programme |
| VERTO Dynamic Line Phantom | Moving line creates centring, uniformity and spatial-resolution patterns; not automatically a renal or cardiac temporal test | Confirm configuration, method and interval in the approved QA programme |
| Quattro 4DCT Respiratory Motion Phantom | Respiratory motion, gating and 4DCT acquisition behaviour | Confirm configuration, method and interval in the approved QA programme |
Flood methods can use a compatible sealed source, refillable source or another approved arrangement. Compare preparation, handling, stability, acquisition time, documentation and return or disposal requirements. Sealed-source authorisation and testing follow the applicable programme; no evidence establishes that most Bangladesh departments prefer one approach.
The catch is that a refillable phantom is only as uniform as the person who filled it. A trapped bubble reads as a cold spot, and a technologist who does not know that will report a detector fault that does not exist.
Follow the phantom manufacturer's filling, mixing, air removal, closure, contamination-check and handling instructions. Confirm source distribution before interpreting a pattern as a camera fault. Use compatible support and storage rather than placing any filled phantom directly on a collimator or carrying it by an improvised method. Record the preparation and acquisition needed to reproduce the approved test.
Departments often buy a bar pattern phantom such as the Four Quadrant Bar Phantom (Rectangular, Square and Circular) and stop there, on the reasoning that if the camera resolves fine bars it must be healthy. It is a reasonable assumption and it is wrong often enough to matter. Resolution and linearity are different properties, and a positioning circuit fault can leave resolution acceptable while bending straight lines across part of the field.
Spatial distortion can affect both planar measurements and tomographic reconstruction. Provide a suitable linearity test where the programme requires it, whether through a separate phantom, a validated combined tool or a manufacturer-specific method.
A tomographic image-quality phantom can test selected aspects of acquisition, reconstruction and correction together. The inserts, filling and method determine what it demonstrates; one acquisition does not independently validate every correction or clinical use.
Software upgrades are the reason this matters more than departments expect. A vendor engineer updates the console, the default reconstruction parameters shift, and the images look slightly different for months before anybody says so out loud. A SPECT IQ acquisition taken before and after the upgrade turns that into a documented, arguable change rather than a feeling.
Use the protocol specified by the test. A standard QA acquisition supports reproducibility and comparison, while a clinical-protocol evaluation answers a different question. Both can be appropriate; neither should universally replace the other.
PET image quality is assessed with its own phantom, because the failure modes differ: contrast recovery for small structures, background variability, and the behaviour of attenuation correction derived from CT. A PET IQ phantom is an acceptance item first and a periodic item second.
Hybrid registration matters for SPECT/CT as well as PET/CT and PET/MR. Compatible multimodality fiducials can support geometric checks, alongside other manufacturer-approved methods. Phantom alignment alone does not prove correct patient registration after motion or differences in positioning.
Small-field PET and microCT research require test objects selected for the scanner geometry and measurement purpose. The preclinical PET/CT phantom selection guide compares the documented roles of NU4 PET IQ, MicroPET PSF and MicroCT test objects and provides a research procurement brief. Use that pathway when the requirement concerns a research system rather than assuming this department-level QA list is interchangeable.
VERTO's documented standard programmes generate centring, uniformity and spatial patterns using a moving line source. Do not infer a validated renogram or cardiac timing test from the word dynamic. Quattro addresses motion-related imaging tests in supported configurations; verify signal interfaces and inserts for the intended gating or 4DCT method.
Where an imaging system serves both nuclear medicine and radiotherapy, coordinate QA responsibilities and assess whether a shared phantom supports both programmes. Confirm the actual local arrangement; it should not be described as a common national use case without evidence.
Before clinical use, provide access to the complete equipment and expertise needed for acceptance, baseline testing and routine QA of the functions being opened. Do not defer SPECT or geometric baselines to the first year if those functions start on day one. Add PET, motion or other tools when the corresponding capability is commissioned, or arrange documented suitable access through the physics programme.
Use proportionate functional and performance requirements, documentation and the applicable procurement procedure. A brand-only specification does not automatically permit a weaker substitution; evaluation must follow the published tender and current rules.
Send Vvon the camera model, installed options and physicist's QA brief to discuss compatible Leeds Test Objects products. Confirm measurement capability, accessories, handling and training in the quotation. Contact +8801805987890 or info@vvon.com.bd.
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