(90 days)
The Anzai eZ-Scope AN Portable Gamma Camera is indicated for use to image the distribution of radionuclides in the human body using planar imaging techniques. The eZ-Scope may be used on pathological specimens if a protective sheath is used.
The Anzai eZ-Scope AN Portable Gamma Camera is a new and innovative portable gamma camera. The camera utilizes a solid state detector, rather than a scintilator, to detect gamma rays. The cadmium-zinc-tellurium detector allows sharp energy discrimination and spatial resolution.
The detector array is made from pixelized cadmium-zinc-telluride (CZT) crystals, with each of the 256 pixels having dimensions of 2 x 2 mm.
The system will be available in two configurations, eZ-Scope AN and eZ-Scope Life. These differ primarily in the computer, the former model using a desktop computer and the latter a laptop. In the desktop version, the computer is mounted on a cart, while the laptop version does not have a cart.
The Anzai eZ-Scope AN Portable Gamma Camera's 510(k) summary (K020643) does not provide a robust study detailing specific acceptance criteria and device performance in a clinical setting.
Instead, it focuses on demonstrating substantial equivalence to predicate devices through technical characteristics and general performance testing relevant to medical devices, rather than a clinical performance study with defined acceptance criteria for diagnostic accuracy.
Here's an analysis based on the provided text, highlighting the absence of some requested information:
1. Table of Acceptance Criteria and Reported Device Performance
Not available. The submission focuses on substantial equivalence to predicate devices (Notebook Imager, Siemens E.CAM, Neoprobe 2000 Isotope Probe) and general device safety and performance, rather than specific diagnostic accuracy metrics.
The document states:
- "For most characteristics, this premarket notification will describe the characteristics of the eZ-Scope in sufficient detail to assure substantial equivalence."
- "For a few characteristics, performance data are provided to assure equivalence."
The "E. TESTING" section lists the types of tests conducted:
- Electrical Safety
- Electromagnetic Compatibility
- NEMA Performance Standard
- Sample Clinical Images
However, it does not provide specific acceptance criteria (e.g., minimum sensitivity, specificity, spatial resolution thresholds) or the quantitative results of these tests that would typically be reported in a table of device performance against such criteria. The "Sample Clinical Images" would likely have been presented qualitatively to demonstrate image acquisition capabilities, but no quantitative performance metrics from these images are reported in the summary.
2. Sample Size Used for the Test Set and Data Provenance
Not available. The document mentions "Sample Clinical Images" were part of the testing, but it does not specify:
- The number of images or patients (sample size) in this test set.
- The country of origin of the data.
- Whether the data was retrospective or prospective.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
Not available. Since details about a specific clinical test set are absent, there is no information on how ground truth was established or the experts involved.
4. Adjudication Method for the Test Set
Not available. Without a defined clinical test set and expert review process, no adjudication method is mentioned.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No. The document does not mention an MRMC study comparing human reader performance with and without AI assistance. The eZ-Scope is a gamma camera, not an AI-driven image interpretation tool that would typically undergo such a study.
6. If a Standalone (Algorithm Only) Performance Study Was Done
Yes, implicitly. The performance testing on "NEMA Performance Standard" and "Sample Clinical Images" would represent a standalone (device-only) performance assessment in terms of its image acquisition capabilities, but not a standalone algorithm performance in the context of AI. The device itself is the "algorithm" that acquires the images. However, no quantitative results are provided in the summary.
7. The Type of Ground Truth Used
Not explicitly stated for the "Sample Clinical Images." For the NEMA Performance Standards, the "ground truth" would be the established physical and imaging characteristics defined by the NEMA standards themselves, where the device's output is compared to expected physical parameters. For "Sample Clinical Images," it's highly likely that the images were qualitatively assessed for their ability to depict radionuclide distribution, possibly compared with images from predicate devices or clinical expectations.
8. The Sample Size for the Training Set
Not applicable. The eZ-Scope AN Portable Gamma Camera is a hardware device for image acquisition, not an AI algorithm that requires a training set of data.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no training set for this type of device.
Summary of Device Rationale for Acceptance:
The acceptance of the Anzai eZ-Scope AN Portable Gamma Camera (K020643) was primarily based on demonstrating substantial equivalence to already legally marketed predicate devices, particularly the Digirad Notebook Imager (K961004), Siemens E.CAM (K992731), and Neoprobe 2000 Isotope Probe (K971320).
The key arguments for substantial equivalence were:
- Similar Indications for Use: "The eZ-Scope is a medical device, and it has similar indications for use and target population as the legally marketed predicate devices."
- Similar Technological Characteristics: "The eZ-Scope has the same technological diagnostic effect. characteristics as the predicate devices." and "The technological characteristics are the same as those of the predicate devices."
- Performance Testing: While specific quantitative results are not provided, general performance testing in key areas (Electrical Safety, EMC, NEMA standards, and sample clinical images) was performed. This testing aimed to confirm that the device operates safely and performs as expected for a gamma camera, aligning with the performance of predicate devices.
The FDA's review letter (K020643) confirms this approach, stating: "We have... determined the device is substantially equivalent... to legally marketed predicate devices..." This implies that the device met the unstated "acceptance criteria" through comparison with well-established devices in the market and by passing general safety and performance tests applicable to gamma cameras. The acceptance criteria were therefore largely defined by the characteristics and performance of the specified predicate devices and relevant industry standards (like NEMA).
§ 892.1100 Scintillation (gamma) camera.
(a)
Identification. A scintillation (gamma) camera is a device intended to image the distribution of radionuclides in the body by means of a photon radiation detector. This generic type of device may include signal analysis and display equipment, patient and equipment supports, radionuclide anatomical markers, component parts, and accessories.(b)
Classification. Class I (general controls).