PTAB

IPR2016-00357

General Electric Co v. University Of Virginia Patent Foundation

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1. Case Identification

  • Case #: IPR2016-00357
  • Patent #: RE44,644
  • Filed: December 16, 2015
  • Petitioner(s): General Electric Co.
  • Patent Owner(s): University of Virginia Patent Foundation
  • Challenged Claims: 75-76, 78-82, 84-92, 94-102, 107-109, 111, 113-115, 118, 128-130, 132-136, 138-140, 157-158, 169-178, 180-184, 186-194, 196-204, 209-211, 213, 215-217, 220, 230-232, 234-238, 240-241, and 254-260.

2. Patent Overview

  • Title: Method and apparatus for spin-echo-train MR imaging using prescribed signal evolutions.
  • Brief Description: The ’644 patent discloses methods and apparatuses for magnetic resonance (MR) imaging using spin-echo pulse sequences. The invention purports to improve upon prior art by explicitly considering T1 and T2 tissue relaxation times to determine a variable-flip-angle series, permitting desired image contrast over long echo trains.

3. Grounds for Unpatentability

Ground 1: Anticipation over Mugler 2000 - Claims 75-76, 78-82, 84-92, 94-96, 107, 111, 139, 152, 157, 160, 169-78, 180-84, 186-94, 196-98, 209, 213, 241, and 254-260 are anticipated by Mugler 2000.

  • Prior Art Relied Upon: Mugler 2000 (an abstract from the Proceedings of the International Society for Magnetic Resonance in Medicine, Apr. 2000).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Mugler 2000, an abstract by the same inventor, disclosed substantially identical subject matter as the ’644 patent. This included using "very long SE trains based on prescribed signal evolutions which explicitly consider the T1s and T2s of interest" to calculate a variable flip-angle RF-pulse series. Petitioner asserted that Mugler 2000 disclosed an identical variable flip-angle series, an identical effective echo time, and identical T2-weighted contrast characteristics as the single example provided in the ’644 patent. For apparatus claims, Petitioner argued the required components (e.g., magnet system, control unit) were inherently disclosed by Mugler 2000’s description of performing imaging on a commercial Siemens MR imager.

Ground 2: Obviousness over Mugler 2000 and Mugler Overview - Claims 75-76, 78-82, 84-92, 94-102, 107-109, 111, 113-14, 118, 128-130, 132-34, 139, 152, 157, 160, 169-78, 180-84, 186-94, 196-204, 209-11, 213, 215-16, 220, 230-32, 234-36, 241, and 254-260 are obvious over Mugler 2000 in view of Mugler Overview.

  • Prior Art Relied Upon: Mugler 2000 and Mugler Overview (a review article, "Overview of MR Imaging Pulse Sequences," Nov. 1999).
  • Core Argument for this Ground:
    • Prior Art Mapping: To the extent the Board found that Mugler 2000 did not explicitly or inherently disclose certain fundamental MR imaging elements (e.g., a data-acquisition step, excitation and refocusing pulses), Petitioner contended these elements were explicitly disclosed in Mugler Overview. Mugler Overview was presented as a general survey of MR imaging pulse sequences that described basic components and steps, such as data-acquisition, excitation/refocusing pulses, and the use of gradient pulses to encode spatial information.
    • Motivation to Combine: A POSITA would combine Mugler 2000 with Mugler Overview because both were in the same field of endeavor, shared a common author, and Mugler Overview provided foundational background knowledge to supplement the specific technique described in the Mugler 2000 abstract. A POSITA seeking to implement the advanced method in Mugler 2000 would naturally consult a general reference like Mugler Overview to understand the underlying principles.
    • Expectation of Success: Success was expected because the combination merely involved applying known, fundamental MR imaging principles from Mugler Overview to the specific pulse sequence calculation method of Mugler 2000, which was a predictable application of established technology.

Ground 3: Obviousness over Mugler 1999 and Alsop - Claims 75-76, 78-82, 84-92, 94-96, 107, 111, 139, 157, 160, 169-78, 180-84, 186-94, 196-98, 209, 213, 241, and 254-260 are obvious over Mugler 1999 in view of Alsop.

  • Prior Art Relied Upon: Mugler 1999 (an abstract, "Three-Dimensional Spin-Echo-Train Proton-Density-Weighted Imaging," May 1999) and Alsop ("The Sensitivity of Low Flip Angle RARE Imaging," a 1997 journal article).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Mugler 1999 disclosed the core invention—calculating a variable-flip-angle series based on a prescribed signal evolution using an iterative, computer-based model—but applied it to generate proton-density-weighted images. Alsop, a key reference cited in the ’644 patent itself, taught using variable-flip-angle sequences for T2-weighted imaging and disclosed how to convert between proton-density and T2-weighted imaging simply by changing the phase-encoding order.
    • Motivation to Combine: A POSITA would combine these references because both addressed the same problem of extending echo train duration using variable flip angles. Mugler 1999 recognized that fast spin-echo sequences were widely used for T2-weighted imaging. A POSITA would have been motivated to apply the advanced pulse sequence calculation from Mugler 1999 to the well-known T2-weighted imaging application taught by Alsop to gain the benefits of longer echo trains for that common imaging modality.
    • Expectation of Success: Success was expected because converting from proton-density to T2-weighted imaging was a simple, well-understood modification (changing the phase-encoding order) with predictable results.

  • Additional Grounds: Petitioner asserted additional obviousness challenges based on combinations of Mugler 2000 or Mugler 1999 with references like Hennig 1986 (for phase angle conditions), Rydberg (for dual-echo techniques), and Stuber (for motion correction).

4. Key Claim Construction Positions

  • "Substance of interest...with corresponding T1 and T2 relaxation times": Petitioner argued this phrase should be construed to mean "the inherent T1 and T2 relaxation times and proton density of a substance...that is imaged." This construction was based on the specification and the Patent Owner's prosecution statements, which confirmed that the claims do not require the active selection of T1/T2 values, distinguishing them from a parent patent.
  • "effective echo time": Petitioner proposed this means "the echo time at which the center of k space is sampled, which can be approximated as ½ of the echo-train duration." This construction was based on the patent's definition and the Patent Owner's infringement contentions, which used this common approximation.

5. Key Technical Contentions (Beyond Claim Construction)

  • Invalid Priority Claim: Petitioner argued that the ’644 patent was not entitled to the filing date of its provisional application (the '182 application). The argument was that the provisional failed the written description requirement of §112 because it described the selection of T1/T2 relaxation times as a required step, whereas the challenged claims omitted this limitation. It also allegedly failed to describe other limitations, such as dephasing magnetic-field gradient pulses and the "at least twice" duration/echo time comparison. Therefore, Petitioner contended the patent's effective filing date was no earlier than December 21, 2001, making publications like Mugler 2000 available as prior art under §102(b).

6. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 75-76, 78-82, 84-92, 94-102, 107-109, 111, 113-115, 118, 128-130, 132-136, 138-140, 157-158, 169-178, 180-184, 186-194, 196-204, 209-211, 213, 215-217, 220, 230-232, 234-238, 240-241, and 254-260 of Patent RE44,644 as unpatentable.