K002113 · Mindways Software, Inc. · KGI · Dec 4, 2001 · Radiology
Device Facts
Record ID
K002113
Device Name
CTXA HIP; CTXA; QCT PRO CTXA HIP
Applicant
Mindways Software, Inc.
Product Code
KGI · Radiology
Decision Date
Dec 4, 2001
Decision
SESE
Submission Type
Traditional
Regulation
21 CFR 892.1170
Device Class
Class 2
Attributes
Software as a Medical Device
Indications for Use
The CTXA Hip Bone Mineral Densitometer is intended to estimate bone mineral content (BMC) and bone mineral density (BMD) in the proximal femur. The BMD estimates can be compared with CTXA Hip-derived reference data. T-scores are calculated with respect to CTXA Hip young normal female reference data, and the T-scores can be used by the physician as an aid in determining fracture risk.
Device Story
Software package for estimation of bone mineral content (BMC) and bone mineral density (BMD) of proximal femur; inputs 3D CT image data sets from compatible whole-body CT scanners and calibration phantoms; derives bone mass/density estimates using quantitative computed tomography (QCT) methods; outputs BMD in g/cm2 (equivalent K2HPO4 density) for femoral neck, trochanter, intertrochanter, Ward's Triangle, and total hip; calculates T-scores based on young normal female reference data; used by physicians to identify low bone density and assess fracture risk.
Clinical Evidence
Clinical studies compared CTXA Hip BMD results against Hologic QDR 1000 and QDR 4500 densitometers. Pearson's R correlations were 0.90-0.97 for Total Hip and 0.88-0.95 for Femoral Neck. Long-term in vivo precision was 0.011 g/cm2 (total hip) and 0.012 g/cm2 (femoral neck). In vitro phantom studies showed precision of 0.007 g/cm2 and unbiased BMD estimates.
Technological Characteristics
Software-based QCT bone densitometer; operates on 3D CT image data; requires compatible whole-body CT scanners and calibration phantoms; outputs BMD in g/cm2 equivalent K2HPO4 density; provides ROI-based analysis (femoral neck, trochanter, intertrochanter, Ward's Triangle, total hip).
Indications for Use
Indicated for patients requiring estimation of bone mineral content and density in the proximal femur to aid physicians in determining fracture risk.
Regulatory Classification
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.
Predicate Devices
QCT Bone Mineral Density Analysis Software (K894854)
Hologic QDR 1000 X-Ray Bone Densitometer (K883280)
Hologic QDR 3000 X-Ray Bone Densitometer (K943505)
Norland Model 178 Bone Densitometer (Preamendment)
Reference Devices
Hologic QDR 4500 bone densitometer
Submission Summary (Full Text)
{0}------------------------------------------------
K002113
# 510(k) SUMMARY OF SAFETY AND EFFECTIVENESS
This summary of safety and effectiveness information is submitted in accordance with the requirements of 21 CFR 807.92(c).
| Contact Information: | Christopher E. Cann, Ph.D.<br>CEO and Director of Research and Development<br>Mindways Software, Inc<br>282 Second St., 4th Floor<br>San Francisco, CA 94105<br>Phone: 415-247-9930<br>Fax: 415-247-9931<br>Email: chris@qct.com |
|----------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Date: | September 28, 2001 |
| Device/Trade Name: | CTXA Hip |
| Common/Usual Name: | Bone Mineral Densitometer |
| Classification Name: | Bone Densitometer, 21 CFR 892.1170, Class II |
| Predicate Devices: | K894854: QCT Bone Mineral Density Analysis Software<br>Intended Use: Estimate bone mineral density within the spine. |
| | K883280: Hologic QDR 1000 X-Ray Bone Densitometer<br>Intended Use: Estimate bone mineral density and bone mineral<br>content at various anatomical sites, including the proximal<br>femur. |
| | K943505: Hologic QDR 3000 X-Ray Bone Densitometer<br>Intended Use: Estimate bone mineral density and bone mineral<br>content at various anatomical sites, including the proximal<br>femur. |
| | Preamendment: Norland Model 178 Bone Densitometer<br>Intended Use: An aid to the physician in determining fracture<br>risk. |
## Device Description
The CTXA Hip Bone Mineral Densitometer (CTXA Hip) is a software package intended for estimation of bone mineral content (BMC), in grams, and bone mineral density (BMD), in glem', of the proximal femur. The CTXA Hip uses quantitative computed tomography (QCT) methods to derive bone mass and bone density estimates from 3D CT image data sets. The CTXA Hip is
{1}------------------------------------------------
intended to be used with compatible, whole-body CT scanners and with compatible CT calibration phantoms. BMD estimates are derived in units of g/cm2 equivalent K2HPO4 density.
## Intended Use
The CTXA Hip Bone Mineral Densitometer is intended to estimate bone mineral content (BMC) and bone mineral density (BMD) in the proximal femur. The BMD estimates can be compared with CTXA Hip-derived reference data. T-scores are calculated with respect to CTXA Hip young normal female reference data, and the T-scores can be used by the physician as an aid in determining fracture risk.
# Summary of Technological Characteristics and Comparison with Predicate Devices
The CTXA Hip Bone Mineral Densitometer Module (CTXA Hip) provides estimates of bone mineral content (BMC) and bone mineral density (BMD) values smilar to those obtained from the predicate DXA devices (K883280: Hologic QDR 1000 X-Ray Bone Densitometer, K943505: Hologic ODR 3000 X-Ray Bone Densitometer) for regions of interest in the proximal femur. CTXA Hip uses the same technical procedures to acquire and calibrate CT image data as are used for the predicate device K894854: QCT Bone Mineral Density Analysis Software. CTXA Hip reference data for young normal US Caucasian females were acquired in a clinical study so that patient results obtained using CTXA Hip can be compared to this normal reference population. The CTXA Hip BMD estimates compared to the CTXA Hip reference population are used as an aid to the physician in identifying patients with low bone mineral density. Additionally, normal data comparisons provide a basis for estimating fracture risk, as is done with the predicate preamendment device Norland Model 178 Bone Densitometer.
BMC and BMD estimates are returned by the CTXA Hip for the following proximal femur regions-of-interest (ROIs): (1) femoral neck, (2) trochanter, (3) intertrochanter, (4) Ward's Triangle, and (5) total hip (i.e., superposition of ROIs 1-3).
### Summary of Non-Clinical Performance Data
In vitro phantom studies with the CTXA Hip indicate a device precision of approximately 0.007 g/cm2 across a variety of CT scanners. These tests also indicate that in vitro CTXA Hip BMD estimates are unbiased when expressed as equivalent K2HPO4 mineral density.
#### Summary of Clinical Performance Data
CTXA Hip clinical studies indicate a long term in vivo device precision of 0.011 g/cm2 for total hip and 0.012 g/cm2 for femoral neck regions of interest. Clinical studies were done comparing BMD results from CTXA Hip with results from Hologic QDR 1000 and QDR4500 bone densitometers. BMD correlations (Pearson's R) were 0.90-0.97 for the Total Hip region of interest and 0.88-0.95 for the Femoral Neck region of interest. A clinical study was done to collect a set of young normal female reference data for calculation of T-scores for CTXA Hip results.
#### Conclusions
{2}------------------------------------------------
The CTXA Hip Bone Mineral Densitometer is substantially equivalent to the listed predicate devices. The CTXA Hip in vitro and in vivo performance is comparable to that associated with the predicate devices. The radiation dose associated with the CT study that provides the data set to be analyzed by the CTXA Hip is well within accepted patient dose guidelines.
lyzed by the CTAA trip is well wi
Signature
Christopher Cann Printed Name
CEO and Director of Research and Development Title
{3}------------------------------------------------
Image /page/3/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo is circular, with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" arranged around the top half of the circle. Inside the circle is a stylized symbol that resembles a bird or an abstract human figure, composed of three curved lines.
Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
DEC 0 4 2001
Christopher E. Cann. Ph.D. CEO and Director of Research Mindways Software, Inc. 282 Second St., 4th Floor SAN FRANCISCO CA 94105 Re: K002113
Trade/Device Name: CTXA HIP, CTXA; QCT PRO CTXA HIP Regulation Number: 21 CFR 892.1170 Regulation Name: Bone densitometer Regulatory Class: II Product Code: 90 KGI Dated: September 28, 2001 Received: October 2, 2001
Dear Dr. Cann:
We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate 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) that do not require approval of a premarket approval application (PMA). 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 (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (sections 531-542 of the Act); 21 CFR 1000-1050.
{4}------------------------------------------------
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), please contact the Office of Compliance at one of the following numbers, based on the regulation number at the top of this letter:
| 8xx.1xxx | (301) 594-4591 |
|----------------------------------|----------------|
| 876.2xxx, 3xxx, 4xxx, 5xxx | (301) 594-4616 |
| 884.2xxx, 3xxx, 4xxx, 5xxx, 6xxx | (301) 594-4616 |
| 892.2xxx, 3xxx, 4xxx, 5xxx | (301) 594-4654 |
| Other | (301) 594-4692 |
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 Part 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address http://www.fda.gov/cdrh/dsma/dsmamain.html.
Sincerely yours,
Nancy C. Brogdin
Nancy C. Brogdon Director, Division of Reproductive, Abdominal, and Radiological Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
{5}------------------------------------------------
Page ***_ of _***
510(k) Number (if known): K002113/S002
Device Name: CTXA Hip Bone ellineral Densitometer
Indications For Use:
### Intended Use
The CTXA Hip Bone Mineral Densitometer is intended to estimate bone mineral content (BMC) The CTAA Hip Bone Mineral Dalishour. The BMD estimates can be compared with CTXA Hip-derived reference data. T-scores are calculated with respect to CTXA Hip young normal female reference data, and the T-scores can be used by the physician as an aid 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<br>(Per 21 CFR 801.109) | ✓ |
|------------------------------------------|---|
|------------------------------------------|---|
OR
| Over-The-Counter Use | |
|----------------------|--------------------------|
| | (Optional Format 1-2-96) |
| (Division Sign-Off) | Nancy C Brogdon |
|------------------------------------------------------------------|-----------------|
| Division of Reproductive, Abdominal,<br>and Radiological Devices | |
| 510(k) Number | K02113 |
Predicate graph will load when search results are available.
Embedding visualization will load when search results are available.
PDF viewer will load when search results are available.
Loading panels...
Select an item from Submissions
Click any panel, subpart, regulation, product code, or device to see details here.
Section Matches
Results will appear here.
Product Code Matches
Results will appear here.
Special Control Matches
Results will appear here.
Loading collections...
Loading
My Alerts
You will receive email notifications based on the filters and frequency you set for each alert.
Sort by:
Create Alert
Search Filters
Agent Token
Create a read-only bearer token for Claude, ChatGPT, or other agents that can call HTTP APIs.
Copy this now. It will not be shown again.
Connected apps
Apps you authorized through browser sign-in. Disconnecting revokes their access immediately.
Learn the FDA Browser
Two short videos show you everything — or skip straight to the written tutorial if you'd rather read. You can reopen this any time from the Tutorial button in the top bar.
Part 1 — Search, results, and everyday workflows 16 min
Part 2 — Embeddings: the galaxy map 3 min
1. Search: exact and fuzzy
Type a phrase like "coronary artery calcification" into the search box. You get two kinds of results. Exact results match the literal phrase — prefix searches work ("coronary artery calcificati") but suffix searches do not. Fuzzy results match on the meaning and intent of your phrase rather than the exact words, and are sorted by relevance score. Hover over the Exact or Fuzzy badge on any row to see exactly why it matched.
Use the checkboxes above the results to narrow: SaMD keeps only software-only devices, AI / ML keeps only devices with AI.
Exact vs. fuzzy search: what's the difference?
Exact matches on the literal phrase (prefix search works, suffix does not). Fuzzy matches on the meaning and intent of the phrase rather than the exact words. Hover over the badge on any row to see why it matched.
You search "coronary artery calcification" and want only software devices with AI. What two filters do you apply?
Narrow by SaMD (software-only devices), then narrow by AI/ML (devices with AI).
2. The results table
Scroll right in the results table. The intended use is extracted for you — no need to open the PDF. The device story gives a high-level snapshot of what the device does and how it's used. The AI Performance sub-table shows each output name, acceptance criteria, observed values, and development/test dataset descriptions — the same format Innolitics uses for regulatory strategy outputs, and the fastest high-level fingerprint of an AI device. It is AI-generated but has been very reliable in practice.
Where do you find a device's intended use without opening the PDF?
Scroll right in the search results table. The intended use column is extracted for you; no need to dig into the 510(k) summary PDF.
What does the AI Performance sub-table show, and why is it useful?
Output name, acceptance criteria, observed values, development dataset description, and test dataset description. It's the same format we use for regulatory strategy output and Fast 510(k) input, and the fastest high-level fingerprint of an AI device. AI-generated but reliable in practice.
3. Judging fuzzy relevance
Fuzzy results trail off in relevance as you scroll. Use three signals to decide how far down to go: the fuzzy badge explanations, the intended use column, and whether your target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, you're past the relevant zone. A top hit with a low score (~0.4) and a stretched explanation is a hint the closest predicates are far away — the project may be headed for De Novo. Note the fuzzy search is a pattern match: it doesn't handle negation ("not") well, and hardware devices can appear — filter by SaMD/AI ML to cut them.
How do you judge how far down fuzzy search results to go?
Use the relevancy signals: the fuzzy badge explanations, the intended use column, and whether the target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, results are trailing off in relevancy.
4. Device detail page: chat and citations
Click a device name to open its detail page: device facts on the left, a chat window on the right. Ask something like "Describe the training data". The answer carries little citation bubbles — click one to jump to the highlighted passage in the source PDF, so you can verify every AI answer against the document. There's also a Download PDF button for sharing.
How do you verify an AI chat answer on the device detail page?
Click the citation bubbles to jump to the relevant highlight in the source document.
Reading rule for every project: how many summaries do you read in full?
At least the three most relevant 510(k) or De Novo summaries, in full. After that, use targeted chat questions to confirm your memory quickly. The tool supports this professional habit — it doesn't replace it.
5. Side-by-side comparison
Select multiple rows in the results table (aim for under ~10), then open the PDF Viewer tab. Ask one question — it goes to all selected devices in parallel, each with citations. This is the fastest way to compare and contrast devices: training data, PCCP scope, how they handled adding new scanners, and so on.
What does the side-by-side PDF viewer mode do?
Select multiple devices, open the PDF viewer tab, and ask one question (e.g., "Describe the training data"). It queries all selected devices simultaneously with citations, so you can compare and contrast quickly.
6. Collections
With rows selected, go to the Collections tab and create a labeled collection (e.g., "Cobb Angle Project"). Reload that selection any time — before a client call, pull up the collection and ask questions across all of its devices at once.
How do you save a set of selected devices for later use?
Select the rows, go to the Collections tab, and create a labeled collection (e.g., "Cobb Angle Project"). You can reload the selection anytime and carry it into the PDF viewer and other tabs that support selections.
7. Product codes and the regulations tree
Click a product code in the results to jump to it in the regulations tree — identification text, sibling product codes, and devices you can open in a PDF viewer on the right. Click a regulation number to see its identification, special controls, and related product codes. You can also search by product code or regulation number at the top of the tree. Always read the special controls if any exist for your device — it broadens your search and sharpens pre-kickoff research.
What can you do from the regulations tree view?
Browse product codes and regulation numbers, read the identification text and special controls, browse sibling product codes, open device PDFs on the right, and search by product code or regulation number at the top of the tree.
8. Chart view
Click Show Chart and segment by regulation number (or product code) to see which regulations dominate your result set. Clicking a regulation takes you into the regulations tree. Great for spotting that most matches are, say, hardware laparoscopic devices — a cue to go back and filter.
How do you see which regulations dominate a search result set?
Click "Show Chart" and segment by Regulation Number. Clicking a regulation takes you to the regulations tree.
9. The predicate graph
Open the Predicates tab for a family-tree view of predicate relationships. Click a node to trace its parents and children; selections from search carry over pre-selected. Commonly predicated devices are worth reading — a lot of people predicated them for a reason. The visual lineage is also handy on client calls, e.g. to show how a predicate family evolved and justify why your predicate still holds.
In the predicate graph, why are commonly predicated devices worth reading?
A lot of people predicated them for a reason. Clicking a node traces parents and children, and selections from search carry over pre-selected.
10. Embeddings: the galaxy map
The Embeddings tab plots every matching document in a 2-D "galaxy map" where semantically similar devices cluster together. Hover or click clusters to explore, and let AI label the clusters for you. Embeddings beat product codes for grouping: two devices can carry different product codes (LLZ vs. QIH) yet do the same thing — the embedding captures the meaning of the intended use and device story. This is also exactly how retrieval-augmented generation (RAG) works under the hood, and it makes a great visual on client calls.
Try it yourself
Head to the search page and work through a few of these AI/ML fuzzy searches to build intuition: perivascular fat on CT · aortic valve calcification opportunistic screening on noncontrast CT · breast cancer prediction on digital pathology slides · autism detection · gestational age prediction · a hearing aid that can also detect a pulse · foundation model based analysis of ECG · large language models · penetration test. Watch how the relevance scores, intended use, and AI Performance tables tell you when results stop being meaningful.