(198 days)
Multitom Rax is a device intended to visualize anatomical structures by converting an X-ray pattern into a visible image. The system has medical applications ranging from gastrointestinations to cranial, skeletal, thoracic and lung exposures as well as examinations of the urogenital tract. The unit may also be used in emergency applications, lymphography, endoscopy, myelography, arthrography, interventional radiology, digital angiography, and digital subtraction angiography (DSA). The system may be used on pediatric, adult, and bariatric patients.
The True2scale Body Scan functionality (i.e., slot-scanning-based acquisition and reconstruction technique) of the Multitom Rax is intended to be used for the genetrically accurate (in scanning direction) 2-D representation of the spine, the lower limbs or the full body which may be used for the assessment of body axes and skeletal alignment. The True2scale Body Scan is not intended to be used for interventional purposes.
The Real3D functionality (i.e., cone-beam CT acquisition and reconstruction technique) of the Multitom Rax is intended to be used for 3-D bone imaging of the head, the upper and lower extremities as well as the lumbar spine. Real3D is not intended for imaging of the torso of patients with a Body Mass Index (BMI) exceeding 30 kg/m².
Multitom Rax is not for mammography examinations.
Multitom Rax is a stationary X-ray system for radiography and fluoroscopy. Multitom Rax consists of a floor mounted patient table (option) and ceiling suspended X-ray tube, and a ceiling suspended Solid State X-ray Imager (SSXI). Together with an X-ray generator and a digital imaging system, Multitom Rax provides comprehensive image acquisition modes to support radiographic and fluoroscopic imaging procedures.
With the True2scale Body Scan technology, Multitom Rax performs a continuous scan that moves along the patient's vertical axis with a highly collimated radiation beam along a line trajectory using the system's two telescopic arms. The projections, which are acquired during the scanning process, form the basis for a reconstruction to obtain a 2D representation of the scanned object.
With the Real3D technology, Multitom Rax performs a continuous, circular scan around the patient using the system's two telescopic arms. The projections, which are acquired during the scanning process, form the basis for a reconstruction to obtain a 3D representation of the scanned object.
The Siemens Multitom Rax device's Real3D functionality (cone-beam CT) was evaluated by comparing its technological characteristics and performance to a legally marketed predicate device (Multitom Rax with True2scale Body Scan Option) and a reference device (CurveBeam LineUP).
Here's a breakdown of the acceptance criteria and study information:
1. Table of Acceptance Criteria and Reported Device Performance
The provided document doesn't explicitly state "acceptance criteria" in a separate section with numerical targets for each performance metric. Instead, the comparison to the reference device (CurveBeam LineUP) serves as the benchmark to demonstrate performance is at least equivalent or better, especially for the newly added CBCT functionality. The acceptance criteria can be inferred from the comparison table where the subject device's performance is listed against the reference device.
| Feature | Reference Device (CurveBeam LineUP) Performance | Subject Device (Multitom Rax Real3D) Performance | Comment / Implied Acceptance |
|---|---|---|---|
| kVp | 100 - 120 | 60 - 130 | Better for Multitom Rax Real3D (Wider range of kVp, implying flexibility and potentially better image quality for diverse patient types and body regions). |
| Voxel size | 0.3 mm | 0.2 mm - 0.5 mm (depending on chosen reconstruction kernel) | Better for Multitom Rax Real3D (Ability to achieve smaller voxel size, indicating higher spatial resolution). |
| Slice spacing | 0.3 mm | 0.2 mm - 0.5 mm (depending on chosen reconstruction kernel) | Better for Multitom Rax Real3D (Ability to achieve smaller slice spacing). |
| FOV (diameter, height) | Regular: 20 cm x 20 cm (d, h) | ||
| Extended: 35 cm x 20 cm (d, h) | Real 3D Hi-Res: 15 cm x 15 cm (d, h) | ||
| Real3D: 23 cm x 23 cm (d, h) | Not directly comparable, but Multitom Rax Real3D has a larger regular FOV. Extended FOV not available for Multitom Rax, but its regular FOV is larger than the reference's regular FOV. This indicates suitability for diverse anatomical regions. | ||
| Scan time* | 23s or 26s | Real3D Hi-Res: 14s | |
| Real3D: 12s or 16s (depending on anatomy) | Better for Multitom Rax Real3D and Real3D Hi-Res (Shorter scan times, reducing patient motion artifacts and patient dose). | ||
| High-contrast resolution (10% MTF) | 12 lp/cm | Real 3D Hi-Res: up to 25 lp/cm (very sharp kernel) | |
| Real 3D: up to 15 lp/cm (sharp kernel) | Better for Multitom Rax Real3D (Significantly higher line pairs per centimeter, indicating superior ability to resolve fine details). | ||
| Low-contrast detectability | n/a | 20 HU @ 4 mm (smooth kernel) | |
| 10 HU @ 8 mm (smooth kernel) | Not reported for CurveBeam LineUP. Justification for adequacy: Intended use is high-contrast bone imaging, so low-contrast detectability is not as critical as for hemorrhage detection. The reported values are therefore considered acceptable for the intended use. | ||
| Slice Sensitivity Profile / z-axis point spread function | Not directly reported (isotropic voxels assumed) | 0.42 mm ± 0.1 mm (Real3D) | |
| 0.31 mm ± 0.1 mm (Real 3D Hi-Res) | Not reported for CurveBeam LineUP. Justification for adequacy: Isotropic resolution for Multitom Rax Real3D is stated, implying consistent resolution in all directions, which is a desirable characteristic. | ||
| Image noise | n/a | Smooth: 20 ± 15 HU | |
| Medium: 60 ± 40 HU | |||
| Sharp: 100 ± 60 HU | |||
| Very sharp: 300 ± 150 HU | Not reported for CurveBeam LineUP. Justification for adequacy: Noise depends on dose, object, and reconstruction kernel, making direct comparison difficult. The reported values are considered acceptable for the intended diagnostic quality of high-contrast bone imaging. | ||
| Uniformity (in-plane) |
§ 892.1650 Image-intensified fluoroscopic x-ray system.
(a)
Identification. An image-intensified fluoroscopic x-ray system is a device intended to visualize anatomical structures by converting a pattern of x-radiation into a visible image through electronic amplification. This generic type of device may include signal analysis and display equipment, patient and equipment supports, component parts, and accessories.(b)
Classification. Class II (special controls). An anthrogram tray or radiology dental tray intended for use with an image-intensified fluoroscopic x-ray system only is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 892.9. In addition, when intended as an accessory to the device described in paragraph (a) of this section, the fluoroscopic compression device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 892.9.