510(k) · Cleared
ClearedSubtleMR (2.3.x)
Data to Oct 25, 2026 (FDA decisions) Oct 12, 2026 (recalls) Sep 30, 2026 (MAUDE) refreshed weekly
Subtle Medical, Inc. · LLZ System, Image Processing, Radiological
Cleared on May 11, 2023 as substantially equivalent to K203182 (Subtle Medical, Inc., 2021) after a 157-day review. Its family tree reaches back 6 generations to 1992. 3 later devices descend from it.
- Decided
- May 11, 2023
- Review
- 157 days
- Class
- Class II
- Product code
- LLZ
- Recalls
- None
- Predicates
- 1
Its longest line of descent runs back 6 generations to K922470 (1992). 3 later devices descend from it, 3 citing it directly.
- Root · 6 generations backK922470 Ies, Image Enhancement SystemOpen Mri, Inc. · 1992
- 5 generations backK993802 Sharpview Image Enhancement SystemContext Vision AB · 2000
- 4 generations backK024028 Sharp View Image Enhancement SystemContext Vision AB · 2003
- 3 generations backK172768 ZOOMZetta Medical Technologies, LLC · 2018
- 2 generations backK191688 SubtleMRSubtle Medical, Inc. · 2019
- 1 generation backK203182 SubtleMRSubtle Medical, Inc. · 2021
- This deviceK223623 SubtleMR (2.3.x)Subtle Medical, Inc. · 2023
- Descendant · cites it directly · 0 of its ownK243250 SubtleHD (1.x)Subtle Medical, Inc. · 2025
- Descendant · cites it directly · 0 of its ownK241681 Overjet Image Enhancement AssistOverjet, Inc. · 2024
- Descendant · cites it directly · 0 of its ownK240290 AiMIFY (1.x)Subtle Medical, Inc. · 2024
Most influential descendants
Showing 3 of 3 · See allView FIG. 1 as a table
Line of descent and top descendants
| Generation | Number | Device | Applicant | Decided | Recalls |
|---|---|---|---|---|---|
| −6 | K922470 | Ies, Image Enhancement System | Open Mri, Inc. | 1992 | — |
| −5 | K993802 | Sharpview Image Enhancement System | Context Vision AB | 2000 | — |
| −4 | K024028 | Sharp View Image Enhancement System | Context Vision AB | 2003 | — |
| −3 | K172768 | ZOOM | Zetta Medical Technologies, LLC | 2018 | — |
| −2 | K191688 | SubtleMR | Subtle Medical, Inc. | 2019 | — |
| −1 | K203182 | SubtleMR | Subtle Medical, Inc. | 2021 | — |
| 0 (this device) | K223623 | SubtleMR (2.3.x) | Subtle Medical, Inc. | 2023 | — |
| +1 | K243250 | SubtleHD (1.x) | Subtle Medical, Inc. | 2025 | — |
| +1 | K241681 | Overjet Image Enhancement Assist | Overjet, Inc. | 2024 | — |
| +1 | K240290 | AiMIFY (1.x) | Subtle Medical, Inc. | 2024 | — |
Descendants by year cleared
| Year cleared | Devices | With a Class I recall |
|---|---|---|
| 2024 | 2 | 0 |
| 2025 | 1 | 0 |
Sources: FDA 510(k) database (decision fields), the FDA summary (predicates and indications), FDA recall and enforcement reports, and MAUDE; processed by 510(k) Report. Verify on FDA.gov · Methodology and accuracy.
Planning a device in LLZ? A 510(k) Report weighs predicate choices, recall history and review times for a new device like this one.
Top candidate predicates for a new LLZ device
- #1 K230955 syngo Application Softwarescore 21.5 · 11 generations · no Class I recall
- #2 Held for the reportin the report
- #3 Held for the reportin the report
What was it cleared against? (1)
Devices the submitter claimed this one is substantially equivalent to (*), and reference devices cited for a specific test or feature (†), as written in the FDA summary.
| Type | Number | Device | Decided |
|---|---|---|---|
| * | K203182 | SubtleMRSummary page 4…Regulation Number: 21 CFR 892.2050 Product Code: LLZ Device Class: Class II Predicate #: K203182 Legally Marketed Predicate Predicate Trade Name: SubtleMR Device:… | 2021 |
What descends from it? (3)
3 later devices cite it directly; ranked here by how many devices descend from each in turn.
Has anything in its family been recalled? (0 Class I)
No FDA recall names this device.
No ancestor or descendant has a Class I recall.
What does this lineage say?
- The line of descent spans 31 years and passes through 4 companies; a new generation was cleared every 3.0 years on median.
- None of the 6 ancestors has a recall.
- Of its descendants, K243250 (Subtle Medical, Inc., 2025) has gone furthest, with 0 descendants of its own.
- 2 other devices also cite its predicate K203182.
How does its category compare?
All LLZ devicesLLZ System, Image Processing, Radiological: FDA decisions, review times, recalls and adverse event reports over 20 years. 2023, this device’s year, is highlighted.
FDA decisions per year · LLZ
58in 2025
2026 to Oct 25, outlined.
Median 510(k) review, days · LLZ
173in 2025
Receipt to decision; years with fewer than 3 clearances left blank.
Recalls per year · LLZ
11in 2025
Class I (0 since 2007) Class II/III not classified
Adverse event reports per year · LLZ
116in 2025
MAUDE reports naming product code LLZ, not matched to any one device; reports are not rates.
View these four charts as a table
| Year | Decisions | Median 510(k) review, days | Recalls (Class I) | MAUDE reports |
|---|---|---|---|---|
| 2007 | 76 | 36 | 20 | 152 |
| 2008 | 94 | 52 | 32 | 154 |
| 2009 | 70 | 62 | 21 | 145 |
| 2010 | 51 | 98 | 17 | 145 |
| 2011 | 106 | 79 | 30 | 454 |
| 2012 | 82 | 87 | 12 | 266 |
| 2013 | 95 | 84 | 64 | 1,130 |
| 2014 | 78 | 89 | 6 | 15,631 |
| 2015 | 64 | 90 | 16 | 211 |
| 2016 | 82 | 90 | 12 | 290 |
| 2017 | 78 | 107 | 5 | 104 |
| 2018 | 104 | 105 | 7 | 72 |
| 2019 | 74 | 107 | 2 | 88 |
| 2020 | 81 | 115 | 6 | 82 |
| 2021 | 83 | 116 | 3 | 70 |
| 2022 | 65 | 137 | 4 | 28 |
| 2023 | 87 | 157 | 8 | 26 |
| 2024 | 62 | 131 | 6 | 42 |
| 2025 | 58 | 173 | 11 | 116 |
| 2026 | 45 | 110 | 14 | — |
What is it indicated for?
SubtleMR is an image processing software that can be used for image enhancement in MRI images.
It can be used to reduce image noise for head, spine, neck, abdomen, pelvis, prostate, breast, and musculoskeletal MRI, or increase image sharpness for head MRI.
Indications for use as stated in the FDA summary.
https://510kreport.com/device/K223623 · printed Nov 6, 2026
Cite this page
510(k) Report. “K223623: SubtleMR (2.3.x).” Lineage record from FDA 510(k) data and the FDA summary. Updated Nov 3, 2026. Accessed Nov 6, 2026. https://510kreport.com/device/K223623
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Record history
- FDA decision record loaded May 2, 2026
- Summary read Oct 13, 2026 (extraction version 9eaa42aa01ed)
- Lineage and recalls computed Nov 3, 2026
- Page last updated Nov 3, 2026