(28 days)
Cardius-1, Cardius-2, Cardius-3:
The Cardius product models are intended for use in the generation of cardiac studies, including planar and Single Photon Emission Computed Tomography (SPECT) studies, in nuclear medicine applications.
2020tc SPECT Imaging System:
The Digirad 2020tc SPECT Imaging system is intended for use in the generation of both planar and Single Photon Emission Computed Tomography (SPECT) clinical images in nuclear medicine applications. The Digirad SPECT Rotating Chair is used in conjunction with the Digirad 2020tc Imager™ to obtain SPECT images in patients who are seated in an upright position.
Specifically, the 2020te Imager™ is intended to image the distribution of radionuctides in the body by means of a photon radiation detector. In so doing, the system produces images depicting the anatomical distribution of radioisotopes within the human body for interpretation by authorized medical personnel.
The changes to the Digirad 2020tc and Cardius SPECT imaging cameras involve addition of an Image Stabilization System. The proposed Image Stabilization System is used to correct image studies for patient motion in SPECT data acquired with Digirad Nuclear medicine gamma camera systems. The Image Stabilization System consists of two parts: a Hardware component that mounts to the SPECT Imaging System, and a software module that collects data from the hardware and corrects the image data for motion. The resulting motion corrected patient study data is referred to as the Image Stabilized Patient Study. The Image Stabilization system may operate only with the above described Digirad Camera models and is compatible with proprietary Digitad Acquisition Software under the Windows Operating system and standard PC architecture.
The proposed Image Stabilization System performs substantially the same function as the currently cleared Cedar's Sinai Motion Correction Program (MoCo), cleared for use on Digirad SPECT Imaging Systems under Digirad 510(k) #K023110.
The proposed Image Stabilization System automatically produces an Image Stabilized Patient Study, corrected for patient motion, which is available in the existing database. The original image study is produced in an identical manner as in the previously cleared devices. Both studies are stored in the same patient record in the database. Additional minor changes were made to the User Interface screen.
The Image Stabilized Patient Studies produced by the proposed device are identical in file structure to the original, unmodified data set; therefore SeeQuanta 1.2 and the Image Stabilization System are fully compatible with the same database, reconstruction software, and processing software that is used with the "cleared" devices. Hence, there are no changes to these software modules.
This proposed optional software addition will be available to Digirad customers both integrated with the Digirad 2020tc SPECT Imaging System, and Cardius-1, Cardius-2, and Cardius-3 SPECT Imaging Systems, and separately as a retrofit device for existing Digirad Product Customers.
Here's an analysis of the provided text regarding the KD5243D 510(k) submission, focusing on the acceptance criteria and study details:
1. Table of Acceptance Criteria and Reported Device Performance
The provided text focuses on the equivalence of the Image Stabilization System to existing predicate devices, rather than establishing new performance metrics. Therefore, explicit numerical acceptance criteria and a direct comparison table as might be seen for a diagnostic accuracy study are not present. Instead, the "acceptance criteria" are implied to be "similar quality" of corrected images.
| Acceptance Criterion (Implied) | Reported Device Performance |
|---|---|
| Image Quality | The quality of the phantom images corrected with the Image Stabilization System with the modified acquisition software was similar to the quality of the images post-processed corrected using the MoCo Motion Correction program (a predicate device). |
| Functionality | The Image Stabilization System performs substantially the same function as the currently cleared Cedar's Sinai Motion Correction Program (MoCo) and other predicate devices (Mirage software, Cedars-Sinai BPGS and MoCo). |
| Design Outputs | Extensive Verification testing was completed on all cleared Digirad SPECT Imaging Systems integrated with the Image Stabilization Device to demonstrate that the design outputs met the design inputs of the proposed Image Stabilization Accessory Device. All software test results met pre-defined acceptance criteria (specific criteria not detailed). |
| Data Compatibility | Image Stabilized Patient Studies are identical in file structure to the original, unmodified data set, ensuring full compatibility with existing database, reconstruction, and processing software. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The text states, "Testing was performed to analyze the content of corrected phantom studies using the Image Stabilization Accessory integrated with the Digirad Cardius-1 camera." It does not specify the number of phantom studies included in this analysis.
- Data Provenance: The testing was performed using "phantom studies," indicating simulated or controlled data rather than patient data. The country of origin for this data is not specified but is presumed to be internal testing by Digirad Corporation (USA). The study is prospective in the sense that the new device was used to correct specific phantom data, but the data itself is not from real patients.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This information is not provided in the text. Since the testing involved phantom studies and comparison to a predicate device's output, it's unlikely that a panel of medical experts was used to establish ground truth in the traditional sense. The "ground truth" for phantom studies is typically defined by the known characteristics of the phantom and the expected ideal image.
4. Adjudication Method for the Test Set
This information is not provided. Given the nature of the testing (phantom studies comparing image quality to a predicate), a formal adjudication method like 2+1 or 3+1 is unlikely to have been employed. The comparison was likely a technical assessment of image characteristics.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not explicitly mentioned or described. The study focused on the technical performance and similarity of image quality for the motion correction system itself, not on the impact of this correction on human reader performance in interpreting patient studies.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, a standalone performance evaluation was conducted. The text describes "Testing was performed to analyze the content of corrected phantom studies using the Image Stabilization Accessory" and "extensive Verification testing was completed on all cleared Digirad SPECT Imaging Systems integrated with the Image Stabilization Device to demonstrate that the design outputs met the design inputs." This indicates the algorithm's performance in correcting phantom images was evaluated independently.
7. The Type of Ground Truth Used
The ground truth used was based on phantom studies and comparison to the output of predicate device software (MoCo). For a phantom, the "ground truth" is the known ideal image of the phantom without motion artifacts. The acceptance criterion was that the corrected phantom images from the new system were "similar in quality" to those corrected by the predicate MoCo program.
8. The Sample Size for the Training Set
This information is not provided. The submission describes the addition of a new hardware and software module for image stabilization. It does not mention whether this module uses a machine learning algorithm that requires a training set. If it's a traditional image processing algorithm, a "training set" in the machine learning sense might not apply.
9. How the Ground Truth for the Training Set Was Established
Since a training set is not mentioned and it's unclear if machine learning was used, the method for establishing its ground truth is not applicable/not provided.
§ 892.1200 Emission computed tomography system.
(a)
Identification. An emission computed tomography system is a device intended to detect the location and distribution of gamma ray- and positron-emitting radionuclides in the body and produce cross-sectional images through computer reconstruction of the data. 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 II.