(117 days)
The SpotLight CT Computed Tomography X-ray is intended to produce cross-sectional images of the body by computer reconstruction of X-ray transmission data taken at different angles. The system has the capability to image whole organs, including the heart, in a single rotation. The system may acquire data using Axial, Cine and Cardiac CT scan techniques from patients of all ages. These images may be obtained either with or without contrast. This device may include signal analysis and display equipment, patient and equipment supports, components and accessories.
This device may include data and image processing to produce images in a variety of trans-axial and reformatted planes.
The system is indicated for X-ray Computed Tomography imaging of organs that fit in a 25cm field of view, including cardiac and vascular CT imaging. The device output is useful for diagnosis of disease or abnormality and for planning of therapy procedures.
The SpotLight CT is a third generation rotate-rotate CT scanner, designed and built based on technologies and principles of operation of the predicate device and other legally marketed CT scanners. The SpotLight CT is a multi-slice (192 detector rows), dual tube CT scanner consisting of a gantry, patient table, operator console, power distribution unit (PDU) and interconnecting cables. The system includes image acquisition hardware, image acquisition and reconstruction software for operator interface and image handling.
The provided document describes the Arineta Ltd. SpotLight CT device and its substantial equivalence to a predicate device. Here's a breakdown of the acceptance criteria and the study details:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state "acceptance criteria" in a tabular format with corresponding "reported device performance." Instead, it describes various performance specifications and how the device performed against them. I've re-framed the reported performance metrics as if they were acceptance criteria.
| Performance Metric (Implied Acceptance Criteria) | Reported Device Performance |
|---|---|
| Coverage (Z-direction) | Up to 140 mm in a single axial scan |
| Field of View (FOV) - Diagnostic | 250 mm (radiation outside 250mm or 160mm FOV is attenuated, providing diagnostic image quality up to 250mm FOV) |
| Gantry Rotation Speed | Up to 0.24 seconds per rotation |
| Temporal Resolution | 120 msec (at 0.24 second rotation speed) |
| Spatial Resolution | 0.31 mm |
| Detector Rows | 192 detector rows |
| Number of X-ray sources | Two ("Gemini" X-ray tubes) |
| Image Quality Evaluation | Evaluated for artifacts, spatial resolution, low contrast detectability, noise, and uniformity and CT number accuracy (details on specific pass/fail not provided, but generally stated as meeting specifications). |
| Dose Performance | Evaluated as meeting specifications |
| Ability to Image Whole Organs | Capable of imaging whole organs, including the heart, in a single rotation. |
| Diagnostic Quality (Animal Testing) | Images were evaluated for diagnostic quality with positive results. |
| Clinical Diagnostic Value & Image Quality (Human Testing) | Demonstrated diagnostic image quality performance. |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set (Clinical Testing): 38 subjects
- Data Provenance: Not explicitly stated, but the study was conducted at "one site," and the readers were "US certified." This suggests the data was collected in the US.
- Retrospective or Prospective: The clinical testing describes "data were collected," which could mean either. However, the phrase "The study protocol was designed to test the scanner across different patient populations, clinical scenarios and scan techniques" implies a prospective study design for collecting new data specifically for this evaluation.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
- Number of Experts: Four (4)
- Qualifications: "US certified readers who are qualified radiologists or cardiologists." Specific years of experience are not mentioned.
4. Adjudication Method for the Test Set
The document states, "The images were evaluated and rated by four US certified readers." It does not specify an adjudication method like 2+1 or 3+1 for resolving discrepancies. It implies independent evaluation by each reader.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- Was an MRMC study done? No, a multi-reader multi-case (MRMC) comparative effectiveness study (comparing human readers with and without AI assistance) was not done. The clinical testing focused on evaluating the device's diagnostic image quality for standalone performance.
- Effect size of human readers with AI vs without AI assistance: Not applicable, as no such study was conducted or reported.
6. Standalone (Algorithm Only) Performance
- Was a standalone study done? Yes, the described "Non-clinical Performance Testing" and "Clinical Testing" primarily focus on the standalone performance of the SpotLight CT system. The image quality, temporal resolution, dose performance, and diagnostic quality evaluations are all measures of the device's inherent capabilities without human intervention during the image generation or initial analysis phase. The "clinical diagnostic value and image quality" evaluated by the readers are also assessing the output of the device itself.
7. Type of Ground Truth Used
- Non-clinical/Phantom Testing: The ground truth for these tests would be objective physical measurements and known parameters of the phantoms used to evaluate image quality metrics (e.g., spatial resolution targets, known low contrast objects, CT number uniformity).
- Animal Testing: The "diagnostic quality" evaluation in animal models likely used established veterinary diagnostic criteria and potentially post-mortem examination or other correlative imaging as ground truth.
- Clinical Testing: The "clinical diagnostic value and image quality" in human subjects were evaluated by "qualified radiologists or cardiologists" against established clinical diagnostic criteria. While not explicitly stated as "expert consensus ground truth," the assessment by multiple, qualified experts serves as the de-facto ground truth for evaluating diagnostic utility. It does not mention pathology or long-term outcomes data for ground truth.
8. Sample Size for the Training Set
The document does not provide any information about a training set since this is a hardware device (CT scanner) with associated imaging software, not typically an AI/ML algorithm that requires a distinct "training set" in the common sense. The image reconstruction algorithm is described as "Stereo CT reconstruction algorithm based on common algorithms used in single source scanners that are modified to combine the data acquired from the two sources." This implies an engineered algorithm, not one trained on a dataset.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no mention of an AI/ML algorithm requiring a training set in the document. The device uses an engineered image reconstruction algorithm.
§ 892.1750 Computed tomography x-ray system.
(a)
Identification. A computed tomography x-ray system is a diagnostic x-ray system intended to produce cross-sectional images of the body by computer reconstruction of x-ray transmission data from the same axial plane taken at different angles. This generic type of device may include signal analysis and display equipment, patient and equipment supports, component parts, and accessories.(b)
Classification. Class II.