(71 days)
The Peripheral Vascular Array is a phased array device which operates in the receiveonly mode. The device is intended to receive signal from hydrogen protons during MR imaging. The Peripheral Vascular Array, as with any surface coil utilized in MR imaging, is intended to provide improved image quality as a result of the high Signal to Noise ratio (SNR) produced when placing a surface coil close to the anatomy of interest. Higher SNR allows the user to prescribe thinner slices and higher matrices necessary for the high spatial resolution needed in making diagnosis.
The Peripheral Vascular Array is primarily designed for imaging of the vascular structures of the abdomen, pelvis, and lower limbs. Soft tissue imaging of these areas may also be evaluated using this device. The design of this coil allows the user to easily image the large peripheral vascular system associated with the abdomen, pelvis and lower limbs without moving the patient of the coil.
Patient fitness and suitability to undergo an MRI exam utilizing the Peripheral Vascular Array must be determined by the individual physician trained in the field of Diagnostic Magnetic Resonance Imaging.
The Peripheral Vascular Array is primarily designed for imaging of the vascular structures of the abdomen, pelvis, and lower limbs. Soft tissue imaging of these areas may also be evaluated using this device. The design of this coil allows the user to easily image the large peripheral vascular system associated with the abdomen, pelvis and lower limbs without moving the patient or the coil.
The Peripheral Vascular coil is designed as a durable item with an expected life of at least 2500 procedures, equivalent to at least five years of service. The specific application of the Peripheral Vascular coil involves MR Imaging at 1.5 Tesla using the GE 1.5T Signa systems with the phased array option.
Here's an analysis of the provided text regarding the acceptance criteria and study for the MEDRAD 1.5T Peripheral Vascular Array:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state quantitative "acceptance criteria" in a pass/fail threshold manner. Instead, it describes performance metrics that were evaluated and compared to a predicate device. The implied acceptance criterion is "equivalent or increased SNR" and "improved image quality and morphological detail" compared to the predicate.
| Performance Metric | Acceptance Criteria (Implied) | Reported Performance |
|---|---|---|
| Signal-to-Noise Ratio (SNR) | Equivalent or increased SNR compared to predicate device (GE 1.5T Body Coil) | "The results were compared to verify the equivalent or increased SNR of the proposed coil." |
| "...substantiate improved SNR and morphological detail with the proposed coil." | ||
| Image Uniformity | Characterized using NEMA MS-6-91 | "Contours of the images obtained with the coil were constructed for the axial image, sagittal image, and the coronal image." (Implies satisfactory characterization) |
| Image Clarity / Morphological Detail | Improved compared to predicate device | "...substantiate improved SNR and morphological detail with the proposed coil." |
| "Image clarity, morphological detail... demonstrate that the Medrad 1.5T Peripheral Vascular Array will produce the required detailed resolution..." |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: Not explicitly stated. The document mentions "clinical testing" where "Images were obtained for the proposed Medrad 1.5T Peripheral Vascular Array and the predicate." However, the number of patients or images in this test set is not provided.
- Data Provenance: Not explicitly stated. Based on the context of a 510(k) submission to the FDA, it is highly likely that this was prospective data collected specifically for the regulatory submission to demonstrate the device's performance. The country of origin is not mentioned, but given "Medrad, Inc." is an American company and the submission is to the FDA, it's reasonable to infer the data was likely collected in the USA.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
This information is not provided in the document. The document mentions that patient fitness and suitability for an MRI exam "must be determined by the individual physician trained in the field of Diagnostic Magnetic Resonance Imaging." However, this refers to the physicians performing the clinical use, not necessarily the expert readers interpreting the test set images for ground truth establishment.
4. Adjudication Method for the Test Set
This information is not provided in the document.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size of Human Improvement with AI vs Without AI Assistance
- MRMC Study: No, an MRMC study was not conducted. This device is a hardware component (MRI surface coil), not an AI algorithm.
- AI Improvement: This question is not applicable as the device is not an AI software/algorithm. The comparison is between two hardware coils (the proposed coil vs. the predicate body coil).
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- This question is not applicable as the device is a hardware component (MRI surface coil), not a standalone algorithm.
7. The Type of Ground Truth Used
The concept of "ground truth" in the typical sense (e.g., pathology, outcomes) for diagnostic algorithm performance is not directly applicable here. For the phantom testing, the "ground truth" was established by NEMA Standard No. 6, Characterization of Special Purpose Coils for Diagnostic Magnetic Resonance Images, which defines the methodology for measuring SNR and uniformity. For the clinical testing, the "ground truth" was essentially the visual assessment of "improved SNR and morphological detail" by presumably experienced radiologists comparing images from the two coils. The document does not specify a separate, independent ground truth method like pathology for the clinical images.
8. The Sample Size for the Training Set
This question is not applicable as the device is a hardware component and does not involve training an algorithm.
9. How the Ground Truth for the Training Set Was Established
This question is not applicable as the device is a hardware component and does not involve a training set or ground truth establishment in that context.
§ 892.1000 Magnetic resonance diagnostic device.
(a)
Identification. A magnetic resonance diagnostic device is intended for general diagnostic use to present images which reflect the spatial distribution and/or magnetic resonance spectra which reflect frequency and distribution of nuclei exhibiting nuclear magnetic resonance. Other physical parameters derived from the images and/or spectra may also be produced. The device includes hydrogen-1 (proton) imaging, sodium-23 imaging, hydrogen-1 spectroscopy, phosphorus-31 spectroscopy, and chemical shift imaging (preserving simultaneous frequency and spatial information).(b)
Classification. Class II (special controls). A magnetic resonance imaging disposable kit intended for use with a magnetic resonance diagnostic device only is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 892.9.