(42 days)
The XCT 2000 L performs a Quantitative Computed Tomography (QCT) scan at various user selectable skeletal sites and measures volumetric bone density (mg/cm3). It provides separate values for the inner core of the bone (trabecular region), the outer ring of the bone (cortical region), and the entire bone (Total). It also provides Axial SSI and Polar SSI values as an aid to physicians in evaluating fracture risk and bone strength. These bone density estimates can also be used as an aid to physicians in determining fracture risk.
The XCT 2000 L performs a Computed Tomography (CT) scan at various user selectable skeletal sites and measures volumetric bone density in mg/cm3. It provides separate values for the inner core of the bone (trabecular region), the outer ring of the bone (cortical region), and the entire bone (Total). It also provides Axial SSI and Polar SSI values as an aid to physicians in evaluating fracture risk and bone strength. These values are calculated from the raw data taken during the CT scan and do not require additional scan time or patient dose. The XCT 2000 L has a 140 mm measurement diameter, a selectable resolution range of 0.2 to 0.8 mm, a typical scan time of 80 seconds, and a typical dose of 40 mRems. It can do multiple scans at selectable spacing. The XCT 2000 L measures a wide variety of skeletal sites, including the Heel (os calcis), Forearm, Knee, and Tibia. The XCT 2000 L has an in vivo precision of < 3 mg/cm3 for the trabecular region and < 9 mg/cm3 for the cortical region. It is calibrated to the COMAC phantom with an accuracy of 2 % The XCT 2000 L also includes Fracture Risk assessment based on the World Health Organization (WHO) criteria.
Here's a breakdown of the acceptance criteria and study information for the Norland XCT 2000 L pQCT Bone Densitometer, based on the provided 510(k) summary:
Acceptance Criteria and Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| In vivo precision (trabecular region) < 3 mg/cm³ | < 3 mg/cm³ |
| In vivo precision (cortical region) < 9 mg/cm³ | < 9 mg/cm³ |
| Accuracy (COMAC phantom) 2% | 2% |
Study Information
The 510(k) summary for the Norland XCT 2000 L pQCT Bone Densitometer describes the device and its performance but does not detail a specific clinical study with sample sizes, expert involvement, or comparative effectiveness. Instead, it focuses on demonstrating substantial equivalence to predicate devices (Norland XCT 960 pQCT bone densitometer K922286 and Fracture Risk Assessment for Norland bone densitometers K980569).
The performance metrics provided (in vivo precision and accuracy) are likely derived from internal testing and validation rather than a large-scale clinical trial described in detail in this summary.
Here's what can be inferred or explicitly stated based on the provided document, addressing your specific points where possible:
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Sample size used for the test set and the data provenance:
- Test Set Size: Not explicitly stated. The document focuses on performance metrics like "in vivo precision" and "accuracy," which imply testing, but the sample size of subjects or phantoms used for these evaluations is not provided.
- Data Provenance: Not explicitly stated. The nature of "in vivo precision" suggests human subjects, but details on location or retrospective/prospective nature are absent.
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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 summary does not describe a process for establishing ground truth via expert review for the performance metrics. The "accuracy" is mentioned in relation to the COMAC phantom, implying a physical standard rather than expert interpretation of images.
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Adjudication method (e.g. 2+1, 3+1, none) for the test set: Not applicable based on the information provided. Expert adjudication is not mentioned, as the device primarily measures physical bone density values.
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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 applicable. This document describes a bone densitometer, not an AI-assisted diagnostic tool requiring human reader improvement studies. The device measures physical parameters and provides calculated values.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: The device itself is a "standalone" system in terms of its measurement capabilities. It performs the CT scan and calculates bone density values, SSI, and T-scores. While physicians interpret the results, the core function of measurement is algorithmic. The precision and accuracy metrics are for this standalone measurement capability.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc):
- For precision, the ground truth is the consistency of repeated measurements on the same subject/phantom.
- For accuracy, the ground truth is the known values of the COMAC phantom.
- The "fracture risk assessment" component uses WHO criteria (T-Scores), which are established clinical guidelines rather than a specific ground truth derived from a study for this device.
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The sample size for the training set: Not applicable. This is a medical device for measurement, not a machine learning algorithm that requires a "training set" in the conventional sense. Its "training" would involve calibration to known physical standards, such as the COMAC phantom.
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How the ground truth for the training set was established:
- The device is "calibrated to the COMAC phantom." The ground truth for this calibration would be the known physical density values of the COMAC phantom.
- The WHO criteria for fracture risk assessment are established clinical guidelines, not a ground truth derived from a training set for this specific device.
In summary, the 510(k) provided focuses on defining the device's measurement capabilities and demonstrating substantial equivalence to existing devices based on its physical performance characteristics (precision and accuracy) rather than presenting a clinical study with detailed statistical analysis of human reader performance or AI algorithm training.
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OCT 79 1998
510k Summary
as required by 807.92(c) for XCT 2000 L pQCT Bone Densitometer Prepared September 1998
Submitted by: Norland Medical Systems, Inc. Contact Person: W6340 Hackbarth Road Mr. Terry Schwalenberg Fort Atkinson, WI 53538 Director Regulatory Affairs Reg. # 2124648 920-563-8456 Device Trade Name: Model XCT 2000 L pQCT Bone Densitometer Common Name: Peripheral quantitative computed tomography bone densitometer Classification: Bone densitometer, (21 CFR 892.1170), product code 90KGI: Class II Predicate Devices: Norland XCT 960 pQCT bone densitometer (K922286). Fracture Risk Assessment for Norland bone densitometers (K980569). Description of The XCT 2000 L performs a Computed Tomography (CT) scan at various Device: user selectable skeletal sites and measures volumetric bone density in mg/cm3. It provides separate values for the inner core of the bone (trabecular region), the outer ring of the bone (cortical region), and the entire bone (Total). It also provides Axial SSI and Polar SSI values as an aid to physicians in evaluating fracture risk and bone strength. These values are calculated from the raw data taken during the CT scan and do not require additional scan time or patient dose. The XCT 2000 L has a 140 mm measurement diameter, a selectable resolution range of 0.2 to 0.8 mm, a typical scan time of 80 seconds, and a typical dose of 40 mRems. It can do multiple scans at selectable spacing. The XCT 2000 L measures a wide variety of skeletal sites, including the Heel (os calcis), Forearm, Knee, and Tibia. The XCT 2000 L has an in vivo precision of < 3 mg/cm3 for the trabecular region and < 9 mg/cm3 for the cortical region. It is calibrated to the COMAC phantom with an accuracy of 2 % The XCT 2000 L also includes Fracture Risk assessment based on the World Health Organization (WHO) criteria. In general, this means that patients with T- Scores above -1 are considered to be normal; with T-Scores from -1 to -2.5 are considered to be osteopenic and have an increased risk of fracture; and T-Scores below -2.5 are considered to be osteoporotic and have a high risk of fracture. Safety and The XCT 2000 L is comparable to other pQCT bone densitometers Effectiveness: currently in the market. It does not raise any new safety or effectiveness issues.
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Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
OCT 2 9 1998
Terry Schwalenberg Director Regulatory Affairs Norland Medical Systems, Inc. W6340 Hackbarth Rd. Fort Atkinson, WI 53538
Re: K983273
XCT 200 L pQCT Bone Densitometer Dated: September 16, 1998 Received: September 17, 1998 Regulatory class: II 21 CFR 892.1170/Procode: 90 KGI
Dear Mr. Schwalenberg:
We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.
If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the Current Good Manufacturing Practice requirements, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic QS inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.
This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.
If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitn diagnostic devices), please contact the Office of Compliance at (301) 594-4613. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address "http://www.fda.gov/cdrivdsmadsmamain.html".
Sincerely yours,
Lillian Yin, Ph.D.
Lillian Yin, Ph.D. Director, Division of Reproductive Abdominal, Ear, Nose and Throx and Radiological Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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INDICATIONS FOR USE STATEMENT
510(K) Number (if known): K983273
Device Name: XCT 2000 L pQCT Bone Densitometer
Indications For Use:
The XCT 2000 L performs a Quantitative Computed Tomography (QCT) scan at various user selectable skeletal sites and measures volumetric bone density (mg/cm3). It provides separate values for the inner core of the bone (trabecular region), the outer ring of the bone (cortical region), and the entire bone (Total). It also provides Axial SSI and Polar SSI values as an aid to physicians in evaluating fracture risk and bone strength.
These bone density estimates can also be used as an aid to physicians in determining fracture risk.
(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED)
Concurrence of CDRH, Office of Device Evaluation (ODE)
Prescription Use
OR
Over-The-Counter-Use
(Per 21 CFR 810.109)
(Division Sign-Off)
Division of Reproductive, Abdominal, ENT,
and Radiological Devices
510(k) Number K983273
§ 892.1170 Bone densitometer.
(a)
Identification. A bone densitometer is a device intended for medical purposes to measure bone density and mineral content by x-ray or gamma ray transmission measurements through the bone and adjacent tissues. This generic type of device may include signal analysis and display equipment, patient and equipment supports, component parts, and accessories.(b)
Classification. Class II.