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                                  [Letter Head]


                                     [Date]

[Name]
[Address]

                  Re:      CONSULTING AGREEMENT

Dear _________:

                  This letter agreement ("Agreement") sets forth the agreement
with respect to your consulting services for Photogen Technologies, Inc. (the
"Company") as a member of the Company's Scientific Advisory Council (the
"Council").

                  1. ENGAGEMENT. Subject to the provisions of this Agreement,
the Company engages you to serve as a consultant and you agree to serve in that
capacity. Your duties will be to participate as a member of the Council and
provide the Company's Board of Directors and management with scientific advice
and counsel regarding the Company's technologies in areas of your professional
expertise. The Council's purposes and structure are described in the attached
resolutions of the Company's Board of Directors. Neither you nor the Council
will take part in formulating and deciding policy issues and you will have
limited access to material non-public information about the Company in order to
avoid becoming an "affiliate" of the Company for purposes of the federal
securities laws.

                  2. COMPENSATION. The Company will reimburse you for travel
expenses you incur to attend meetings of the Council and for all reasonable
out-of-pocket expenses you incur for activities authorized and directed by the
Company. You will also be eligible to receive awards of non-qualified options to
acquire shares of the Company's common stock or shares of restricted Company
stock, in accordance with the Photogen Technologies, Inc. 1998 Long Term
Incentive Compensation Plan as administered by the Compensation Committee of the
Company's Board of Directors.

                  3. CONFIDENTIAL INFORMATION. (a) Although you and the Company
will use their best efforts to minimize your access and exposure to Confidential
Information (defined below), if as a result of your engagement under this
Agreement you have access to Confidential Information you agree that during your
engagement hereunder and at all times thereafter, you will hold in trust, keep
confidential and not disclose, directly or indirectly, to any third parties or
make any use of the Company's Confidential Information for any purpose except
for the benefit of the Company in the performance of your duties under this
Agreement. Confidential Information which, without your fault, becomes generally
known to the public or in the industry, or in which the Company ceases to have a
legally protectable interest, will cease to be subject to these restrictions.
Upon termination of this Agreement (regardless of the reason for termination),
you will immediately return to the Company all tangible Confidential Information
and any other material, including information stored in electronic format and



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handwritten notes, made or derived from Confidential Information, which is in
your possession or which you delivered to others.

                  (b) "Confidential Information" means any and all information
that has or could have value or utility to the Company, whether or not reduced
to written or other tangible form and all copies thereof, relating to the
Company's private or proprietary matters, confidential matters or trade secrets
(including all such matters relating to the Company's subsidiary, Photogen,
Inc.). Confidential Information includes, but is not limited to the following:

                  (i) technical information (whether or not subject to patent
         registration or protection), such as research and development, methods,
         trade secrets, know-how, formulas, compositions, protocols, processes
         and techniques, discoveries, machines, inventions, ideas, computer
         programs (including software and data used in all such programs),
         drawings, specifications;

                  (ii) except to the extent publicly disclosed by the Company
         without any fault by you, information relating to the Company's
         patents, patent applications, and patent disclosures, together with all
         reissuances, continuations, continuations-in-part, revisions,
         extensions, and reexaminations thereof, and all improvements and
         inventions related thereto;

                  (iii) business information, such as information concerning any
         products, customer and supplier lists, production, developments, costs,
         purchasing, pricing, profits, markets, sales, accounts, customers,
         financing, acquisitions, strategic alliances or collaborations,
         expansions; and

                  (iv) other information relating to the Company's or any of its
         affiliates' business practices, strategies or policies.

                  4. TERM; TERMINATION. The term of this Agreement will commence
on the date you countersign a copy of this Agreement below, and may be
terminated by you or the Company at any time, with or without cause, by written
notice to the other. Your obligations under Paragraph 3 survive termination.

                  5. SEVERABILITY; CHOICE OF LAW; INJUNCTION. If any provision
of this Agreement is deemed by a court of competent jurisdiction to be
unenforceable or invalid, the enforceability and validity of all other
provisions hereof shall not be affected thereby and such court shall modify the
unenforceable or invalid provision to the extent necessary to render it
enforceable and valid and such provision shall be enforced as modified. You
agree that the time period and scope of the covenants in Paragraph 3 are
reasonable and appropriate under the circumstances of the Company's business and
your unique skills. This Agreement shall be governed and interpreted in
accordance with the laws of the State of Tennessee without regard to its
provisions on conflicts of law. Without limiting any other available remedies at
law or in equity, the Company will be entitled to injunctive relief restraining
any individual


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or entity from participating in any breach or threatened breach of this
Agreement without having to post a bond or security.

                  6. INDEPENDENT CONTRACTOR. The parties' relationship to one
another under this Agreement of that of independent contractors. You are not an
employee or agent of the Company and you have no authority to bind or incur
liability for the Company except as may be expressly authorized in writing. You
agree that the Company may disclose the existence of the Council and your
membership on the Council in its filings with the Securities and Exchange
Commission and other governmental entities. You will provide the Company with an
up-to-date curriculum vitae describing your expertise and other professional
associations and affiliations.

                  7. MISCELLANEOUS. This Agreement may not be amended or
modified except by a written instrument signed by both parties after the date of
this Agreement. This Agreement may be assigned by the Company and shall inure to
the benefit of the Company, its successors and assigns, but may not be assigned
or delegated by you. This Agreement supersedes all prior agreements,
negotiations and representations, written or oral, between the parties with
respect to the subject matter contained herein. Any waiver of any breach of, or
failure to enforce, any of the provisions of this Agreement shall not operate as
a waiver of any other breach or waiver of performance of such provisions or any
other provisions.

                  Please indicate your agreement to the foregoing by signing a
copy of this letter below and returning it to me. I look forward to working with
your in this exciting endeavor.

                                                     Very truly yours,



                                                     John T. Smolik, President
Accepted and Agreed to
as of ________________.


By:_____________________