Model note · PEM
PEM Flex PEMFlex Solo II High Resolution PET Scanner
The Solo II is a positron emission mammography (PEM) system: a small field-of-view, partial-ring PET scanner whose two detector heads sit inside breast compression paddles. It is used in breast imaging centres to image uptake of positron-emitting tracers at close range, and can guide biopsy with a separate accessory. Its distinctive trait is very high in-plane resolution from small lutetium-based crystals placed directly against the breast.
The model
Maker, model and type.
- Maker
- Naviscan, Inc. (now CMR Naviscan)
- Model
- PEMFlex Solo II High Resolution PET Scanner
- Device type
- PEM
- Main document
- Open the public document
Key specifications
What the public record says.
| Item | Value | Source |
|---|---|---|
| Detector heads | Two opposing detectors inside compression paddles, each about 6 x 16.4 cm imaging area and about 6 cm thick; one is motor controlled | Source |
| Scintillator | 2 x 2 x 13 mm lutetium yttrium orthosilicate crystals on position-sensitive photomultiplier tubes | Source |
| Maximum field of view | 24 x 16.4 cm, by scanning the heads across their 6 cm dimension | Source |
| Measured spatial resolution (FWHM) | About 2.4 mm in-plane and 8.0 mm cross-plane (independent evaluation) | Source |
| Energy window | 350 to 700 keV software window | Source |
| Reconstruction | 3D list-mode MLEM, 5 iterations, 1.2 mm in-plane pixels, 12 or 24 slices | Source |
| Primary compression safety limit | 15 lb pre-compression force, at which paddle movement stops automatically | Source |
| FDA clearance | 510(k) K090553, product code KPS, 21 CFR 892.1200; predicate Naviscan PEM 2400 (K032063) | Source |
Recalls
Known FDA recalls.
- Z-2229-20082008-06-19
Motorised compression could exceed 25 lb because a secondary fault protection did not work as expected.
FDA record - Z-0041-20082007-08-01
PEMView software could give inaccurate uptake and distance measurements in some zoomed images.
FDA record
Safety
Safety warnings from the record.
- Continuing motorised compression past the primary limit could exceed 25 lb and cause discomfort or injury. Source
- Uptake values are not corrected for scatter, randoms or attenuation and vary with position, so they are reported as PEM uptake values, not SUV. Source
- Positioning is accurate only from about 13 mm in from the detector housing edge, which limits imaging near the chest wall. Source
Sources
Where this note comes from.
- FDA 510(k) summary K090553, PEMFlex Solo II
- MacDonald et al., Clinical imaging characteristics of the PEM Flex Solo II, J Nucl Med 2009
- CMR Naviscan home page
- openFDA recall search, Naviscan
- openFDA MAUDE problem counts, PEM Flex
Not covered: CMR Naviscan's current site does not describe the Solo II, and no public operator or service manual or error code list was found; specifications come from the 510(k) and an independent 2009 evaluation. MAUDE holds only a handful of reports, so failing parts are thin.
BMEssentia knowledge drafted from public information, reviewed by Hasan Khaled Ismail on 2026-10-24. Always follow the manufacturer's instructions for use and service manual.