(141 days)
The Spectral CT system is a Computed Tomography X-ray system intended to produce cross-sectional images of the body by computer reconstruction of X-ray transmission data taken at different angles and planes. This device may include signal analysis and display equipment, patient and equipment support, component parts, and accessories.
The Spectral CT system acquires one CT dataset – composed of data from a higher-energy detected X-ray spectrum and a lower- energy detected X-ray spectrum. The two spectra may be used to analyze the differences in the energy dependence of the attenuation coefficient of different materials. This allows for the generation of images at energies selected from the available spectrum and to provide information about the chemical composition of the body materials and/or contrast agents.
Additionally, materials analysis provides for the quantification and graphical display of attenuation, material density, and effective atomic number.
This information may be used by a trained healthcare professional as a diagnostic tool for the visualization and analysis of anatomical and pathological structures in patients of all ages, and to be used for diagnostic imaging in radiology, interventional radiology, and cardiology and in oncology as part of treatment preparation and radiation therapy planning. The Extended field of view images and respiratory correlated scanning (4DCT) are for treatment preparation and radiation therapy planning/simulation usage only.
This device is indicated for head, whole body, cardiac and vascular X-ray Computed Tomography applications in patients of all ages.
The system is also intended to be used for low dose CT lung cancer screening for the early detection of lung nodules that may represent cancer*. The screening must be performed within the established inclusion criteria of programs / protocols that have been approved and published by either a governmental body or professional medical society.
*Please refer to clinical literature, including the results of the National Lung Screening Trial (N Engl. J Med 2011; 365:395-409) and subsequent literature, for further information.
Spectral CT system is a whole-body computed tomography (CT) X-ray system featuring a continuously rotating X-ray tube and detectors gantry, and multi slice capability. The acquired X-ray transmission data is reconstructed by computer into cross-sectional images of the body taken at different angles and planes. This system also includes signals analysis and display equipment, patient and equipment support, components, and accessories.
The Spectral CT system acquires one CT dataset – composed of data from a higher energy detected X-ray spectrum and a lower- energy detected X-ray spectrum. The two spectra may be used to analyze the differences in the energy dependence of the attenuation coefficient of different materials. This allows for the generation of images at energies selected from the available spectrum and provides information about the chemical composition of the body materials and/or contrast agents. Additionally, materials analysis provides for the quantification and graphical display of attenuation, material density, and effective atomic number.
The Spectral CT system consists of three main components – a scanner system that includes a rotating gantry, a movable patient couch, and an operator console for control and image reconstruction; a Spectral Reconstruction System; and a Spectral CT Viewer. On the gantry, the main active components are the X-ray high voltage (HV) power supply, the X-ray tube, and the detection system.
The fundamental design and characteristics of the main components used in the proposed Spectral CT system are identical to the currently marketed primary predicate device, Spectral CT system (K203020).
This document is a 510(k) clearance letter for a Spectral CT System, indicating its substantial equivalence to previously cleared predicate devices. While it focuses heavily on design features and compliance with general safety and performance standards for CT systems, it does not contain the detailed clinical study information typically found in submissions for AI/ML-based medical devices that require specific performance metrics and human reader studies.
The provided text only briefly mentions "Clinical Image Evaluation" and "Comparison of performance data against internal performance requirements" as supporting the evaluation of new features. It does not provide specific acceptance criteria or performance results for these "new features" (Pulmonary Gating 4DCT and Extended Field of View (EFOV)) in the context of a clinical study, nor does it detail how substantial equivalence was demonstrated clinically for these features beyond a generic statement.
Therefore, many of the requested items cannot be extracted from this document, as it primarily covers the device's technical specifications and regulatory compliance for a general CT system, rather than specific performance studies for new AI/ML functionalities.
Given the information provided, here's what can be extracted and what cannot:
Acceptance Criteria and Study for Spectral CT System (K244008)
Based on the provided FDA 510(k) clearance letter, the primary method for demonstrating the device meets acceptance criteria and proving its performance is through substantial equivalence to predicate devices and adherence to recognized consensus standards and guidance documents. The document does not detail specific performance metrics, acceptance criteria, or a clinical study for the new features (Pulmonary Gating 4DCT and Extended Field of View (EFOV)) in the format requested for AI/ML device performance.
The document states:
- "Non-clinical performance testing has been performed on the proposed Spectral CT system and demonstrates compliance with the following International and FDA recognized consensus standards and FDA guidance document(s)..."
- "Design verification planning and testing were conducted at the system level. The system is tested against the System Requirements Specifications (SRS)."
- "Design Validation tests the user needs and intended use that are documented in the top-level User Requirement Specification (PRS)."
- "All the validation tests as per validation plan were performed and acceptance criteria met for each of the requirements."
- "Non-clinical design validation testing demonstrates that the proposed Spectral CT system can be used as defined in its clinical workflow and intended use."
- "To support the evaluation of the new features, the submission includes: - Phantom-based image quality (IQ) testing, assessing parameters such as noise, resolution, and artifacts - A representative clinical image assessment - Comparison of performance data against internal performance requirements"
This indicates that the "acceptance criteria" are primarily framed around compliance with established engineering and regulatory standards and internal performance requirements verified through non-clinical and limited clinical assessment, rather than a specific clinical trial with defined performance endpoints for the new features.
Information Extracted from the Document:
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A table of acceptance criteria and the reported device performance:
The document does not provide a table of specific quantitative acceptance criteria and corresponding reported device performance metrics from a clinical study for the new features (Pulmonary Gating 4DCT and Extended Field of View (EFOV)). Instead, it states that "All the validation tests as per validation plan were performed and acceptance criteria met for each of the requirements." without detailing these.
The primary "performance" discussed is the technological equivalence to predicate devices. Below is a summary of the technological characteristics being presented as "met" by being identical or substantially equivalent to the predicate.Table: Technological Characteristics (Implicit Acceptance Criteria - Equivalence to Predicate)
| Design Feature | Acceptance Criteria (Equivalent to K203020/K240844) | Reported Performance (Proposed Device) |
|---|---|---|
| Design and Fundamental Scientific Technology | ||
| Application | Head, Body and Cardiac | Head, Body and Cardiac |
| Scan regime | Continuous Rotation | Continuous Rotation |
| Scan Field of View (SFOV) | Up to 500 mm (Identical to K203020) | Up to 500 mm |
| Extended Field of View (EFOV) | Up to 800 mm (Identical to K240844) | Up to 800 mm (for non-gated Helical scans, RT planning) |
| No. of slices | Up to 128 slices of 0.625 mm | Up to 128 slices of 0.625 mm |
| Scan modes | Surview, Axial-after-Axial Dynamic Scan, Helical Scan | Surview, Axial-after-Axial Dynamic Scan, Helical Scan |
| Spatial Resolution | 16 lp/cm max (high mode), 13 lp/cm max (standard mode) | 16 lp/cm max (high mode), 13 lp/cm max (standard mode) |
| Minimum Scan time | 0.18 sec for 240° rotation, 0.27 sec for 360° rotation | 0.18 sec for 240° rotation, 0.27 sec for 360° rotation |
| Scan coverage | Scanner Center of Rotation (COR) is up to 80 mm | Scanner Center of Rotation (COR) is up to 80 mm |
| Low contrast resolution (32cm body CTDI phantom) | 4 mm @ 0.3% @ 25 mGy CTDIvol | 4 mm @ 0.3% @ 25 mGy CTDIvol |
| Noise in (as standard mode measured on 21.6 cm water-equivalent) | 0.27% at 27 mGy | 0.27% at 27 mGy |
| Image Matrix | Up to 1024 x 1024 | Up to 1024 x 1024 |
| Display | 1024 x 1280 | 1024 x 1280 |
| Communication | Compliance with DICOM 3.0 | Compliance with DICOM 3.0 |
| Detectors | ||
| Type | Nano Panel Prism | Nano Panel Prism |
| Material | Solid-state yttrium-based scintillator, GOS + Photodiode | Solid-state yttrium-based scintillator, GOS + Photodiode |
| DMS Detector Spectral CT 7500 | 8 cm - Dual-Layer scintillator, up to 128 detector rows | 8 cm - Dual-Layer scintillator, up to 128 detector rows |
| DMS structure | Spherical DMS structure | Spherical DMS structure |
| Collimation | 0.625 mm and various combinations | 0.625 mm and various combinations |
| Gantry | ||
| Gantry rotation speed | 0.27 sec -1.5 sec (360° rotation), 0.18 sec, 0.2 sec (240° rotation) | 0.27 sec -1.5 sec (360° rotation), 0.18 sec, 0.2 sec (240° rotation) |
| Bore size | 800 mm | 800 mm |
| Operator Controls located on Gantry | Touch Panel Controls | Touch Panel Controls |
| Eclipse Collimation | A-Plane | A-Plane |
| Generator and Tube Performance | ||
| Power | 120kW | 120kW |
| kV Setting | 80, 100, 120, 140 | 80, 100, 120, 140 |
| mA Range | 10-1000 | 10-1000 |
| Couch | ||
| Couch | Noah Couch | Noah Couch |
| Couch Vertical Range | Minimum Height – 430 mm | Minimum Height – 430 mm |
| Couch Horizontal Range | -2143 mm | -2143 mm |
| Scannable Surview Range | 1940mm | 1940mm |
| Scannable axial Range | 2000mm | 2000mm |
| Scannable helical Range | 1900mm | 1900mm |
| Couch Speed Range | 1 mm/sec – 600 mm/sec | 1 mm/sec – 600 mm/sec |
| Acceleration | 800 mm/Sec^2 | 800 mm/Sec^2 |
| Couch Max Load Capacity | High Performance: 675 lbs. (307 kg), RTP Tabletop: 628 lbs. (285 kg) | High Performance: 675 lbs. (307 kg), RTP Tabletop: 628 lbs. (285 kg) |
| Couch accessories | Infant Cradle, Paper roller, Varian Camera Adaptor, Oncology flat tabletop | Infant Cradle, Paper roller, Varian Camera Adaptor, Oncology flat tabletop |
| Clinical Applications: Dose Tools | ||
| Cardiac reconstruction method | Standard ECG Gated Reconstruction, Motion Compensated Reconstruction (optional) | Standard ECG Gated Reconstruction, Motion Compensated Reconstruction (optional) |
| Virtual Tilt Viewer (VTV) (optional) | Yes | Yes |
| Pulmo & 4DCT | Feature introduced, deemed substantially equivalent to K240844 | Pulmonary gated scanning for RT planning procedures |
| General | ||
| Technical Basis for Collection of two CT Spectral | Dual Layer DMS (Spectral Detector) | Dual Layer DMS (Spectral Detector) |
| Spectral Base Images | Low energy, High-energy, Photoelectric, Compton Scatter | Low energy, High-energy, Photoelectric, Compton Scatter |
| Spectral results available [kVp] | 100kVp, 120kVp, 140kVp | 100kVp, 120kVp, 140kVp |
| Spectral Results Images | Monoenergetic, Materials Basis/Density Pairs, Electron Density, etc. | Monoenergetic, Materials Basis/Density Pairs, Electron Density, etc. |
| Host Drives | 256GB OS disk Plus one 7.68TB PCIE NVMe SSD | 256GB OS disk Plus one 7.68TB PCIE NVMe SSD |
| Host Infrastructure | Windows 10 | Windows 10 |
| CIRS Computers | CIRS Rack with two HP Z8 servers (option for two additional) | CIRS Rack with two HP Z8 servers (option for two additional) |
| CIRS CPUs | Dual Intel Gold 6230 with 20 cores at 2.1GHz each | Dual Intel Gold 6230 with 20 cores at 2.1GHz each |
| CIRS Drives | 512GB NVMe SSD for OS/software, Two 2TB NVMe SSDs for raw data | 512GB NVMe SSD for OS/software, Two 2TB NVMe SSDs for raw data |
| Interventional Controls | Yes | Yes |
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Sample sizes used for the test set and the data provenance:
Not explicitly stated in the provided text. The document refers to "Phantom-based image quality (IQ) testing" and "A representative clinical image assessment" but does not give sample sizes or provenance (country/retrospective/prospective) for these.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
Not explicitly stated. The document refers to "A representative clinical image assessment" but does not detail how ground truth was established or the experts involved.
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Adjudication method (e.g. 2+1, 3+1, none) for the test set:
Not explicitly stated.
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If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance:
Not explicitly stated. This type of study is typically done for AI/ML diagnostic tools where human interpretation of medical images is directly affected by the AI output. This 510(k) is for a CT system itself, with new acquisition and reconstruction features (4DCT, EFOV) that are likely intended to provide better images for human interpretation, rather than an AI reading a dataset. The document's statements about "clinical image evaluation" do not elaborate on how this was conducted or whether it involved comparative effectiveness with human readers.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
This question is more applicable to diagnostic algorithms. For a CT system with new acquisition/reconstruction capabilities, the "standalone" performance would typically refer to the "Phantom-based image quality (IQ) testing," where the system's output (images) are assessed against objective physical metrics (noise, resolution, artifacts) without human interpretation of clinical findings. The document states this was done: "Phantom-based image quality (IQ) testing, assessing parameters such as noise, resolution, and artifacts."
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
For the "Phantom-based IQ testing," the ground truth would be the known physical properties and measurements of the phantoms.
For the "representative clinical image assessment," the type of ground truth is not specified. -
The sample size for the training set:
Not applicable. This 510(k) is for a CT hardware and software system, not an AI/ML diagnostic algorithm that would typically have a "training set" in the machine learning sense. The "new features" (Pulmonary Gating 4DCT and EFOV) are descriptions of how the system acquires and processes data, not separate AI algorithms trained on massive datasets to perform a diagnostic task.
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How the ground truth for the training set was established:
Not applicable, as there's no mention of a "training set" in the context of an AI/ML 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.