(132 days)
ECG-less Cardiac streamlines patient preparation by enabling an alternative acquisition of cardiac CT images for general cardiac assessment without the need of a patient-attached ECG monitor. ECG-less Cardiac is for adults only.
ECG-less Cardiac is a software device that is an additional, optional cardiac scan mode that can be used on the Revolution Apex Elite, Revolution Apex, and Revolution CT with Apex edition systems. There is no change to the predicate device hardware to support the subject device. Currently, the available cardiac scan modes on the Revolution CT Family are Cardiac Axial and Cardiac Helical, which makes use of an ECG signal to physiologically trigger the cardiac acquisitions and/or to retrospectively gate the reconstruction.
ECG-less Cardiac is a third cardiac scan mode that introduces the ability to acquire cardiac images without the need of a patient-attached ECG monitor. Hence, an ECG signal from the patient is not utilized for this scan mode. The ECG-less Cardiac workflow leverages the full-heart coverage capability of 160 mm configurations, fast gantry speeds (0.28 and 0.23 s/rot), and existing cardiac software options of SmartPhase and SnapShot Freeze 2 (K183161) to acquire images that are suitable for coronary and cardiac functional assessment.
The ECG-less cardiac feature allows the user to acquire a cardiac CT scan without the need to complete the steps associated with utilizing an ECG monitor, such as attaching ECG electrodes to the patient, checking electrode impedance, and confirming an ECG trace is displayed on the operator console, thus optimizing the workflow.
ECG-less Cardiac may be best utilized in examinations where excluding the ECG connection would streamline the patient examination, including and unloading of the patient. This may result in an improved workflow for certain clinical presentations. ECG-less Cardiac may also increase access to cardiac assessment for patients that are difficult to receive an ECG signal from. Circumstances where the subject device is expected to increase cardiac access includes scenarios where trauma patient has a diagnostic ECG attached and/or other instrumentation, such that there is added difficulty of attaching ECG leads for a gated scan, and situations where it is challenging to get an ECG signal from a patient such as a patient's t-wave triggering the scan or R-peak being difficult to detect.
Here's a summary of the acceptance criteria and the study proving the device meets them, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are implicitly derived from the study's conclusions, focusing on diagnostic utility and image quality. No specific quantitative thresholds for acceptance are explicitly stated in the document beyond "interpretable without a significant motion artifact penalty" and "of diagnostic utility."
| Acceptance Criteria (Inferred) | Reported Device Performance |
|---|---|
| Diagnostic Utility | ECG-less Cardiac acquisitions were consistently rated as interpretable and of diagnostic utility by board-certified radiologists who specialize in cardiac imaging. |
| Image Quality (Motion Artifact) | Images generated from ECG-less Cardiac acquisitions were consistently rated as interpretable without a significant motion artifact penalty. |
| Equivalence to ECG-gated "ground truth" | Engineering bench testing showed that ECG-less Cardiac scan acquisitions can produce images that are equivalent to an ECG-gated "ground truth" nominal phase location. |
| Safety & Effectiveness | The device is deemed safe and effective for its intended use based on non-clinical testing and the clinical reader study. |
2. Sample Size Used for the Test Set and the Data Provenance
- Sample Size for Test Set: The document does not explicitly state the exact number of cases or images included in the reader study (test set). It refers to "a reader study of sample clinical data" and "prospectively collected clinical data."
- Data Provenance: The data was prospectively collected clinical data from patients undergoing a routine cardiac exam. The country of origin is not specified.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
- Number of Experts: Three experts were used.
- Qualifications of Experts: They were board-certified radiologists who specialize in cardiac imaging. The document does not specify their years of experience.
4. Adjudication Method for the Test Set
The adjudication method is not explicitly stated. The document mentions that each image was "read by three board certified radiologists who specialize in cardiac imaging who provided an assessment of image quality." This suggests independent readings, but it does not detail a consensus or adjudication process (e.g., 2+1, 3+1).
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and the Effect Size of How Much Human Readers Improve with AI vs. Without AI Assistance
- No, an MRMC comparative effectiveness study involving human readers improving with AI vs. without AI assistance was not conducted or reported.
- The study was a reader study where experts assessed images generated by the ECG-less Cardiac system. The primary goal was to validate the diagnostic utility and image quality of the ECG-less Cardiac acquisitions themselves, not to assess human reader performance with or without an AI assist feature.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, a form of standalone performance was assessed in the engineering bench testing. This testing "assessed how simulated ECG-less Cardiac scan conditions performed against an ECG-gated 'ground truth' nominal phase location." This component evaluated the algorithm's ability to generate images comparable to traditional ECG-gated acquisitions without human interpretation being the primary focus.
7. The Type of Ground Truth Used
- For the engineering bench testing, the ground truth was an ECG-gated "ground truth" nominal phase location. This implies a comparison to a known, established reference standard for cardiac imaging synchronization.
- For the clinical reader study, the ground truth was effectively the expert consensus/assessment of the three board-certified radiologists regarding the interpretability, motion artifact, and diagnostic utility of the ECG-less images. There is no mention of pathology or outcomes data being used as ground truth for this part of the study.
8. The Sample Size for the Training Set
The document does not provide any information regarding the sample size used for the training set of the ECG-less Cardiac software.
9. How the Ground Truth for the Training Set Was Established
The document does not provide any information on how the ground truth for the training set was established. It only discusses the testing (validation) phase.
§ 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.