UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934

                                (Amendment No. 2 )*

                                    MDS Inc.
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                                (Name of Issuer)

                                  Common Stock
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                         (Title of Class of Securities)

                                    55269P302
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                                 (CUSIP Number)

                                December 31, 2007
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             (Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

         [X] Rule 13d-1(b)

         [ ] Rule 13d-1(c)

         [ ] Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities,
and for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).



                                  SCHEDULE 13G

CUSIP No. 55269P302

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      1.   Names of Reporting Persons.  I.R.S. Identification Nos. of above
           persons (entities only).
           Invesco Ltd.
                       AIM Advisors, Inc.
                       AIM Funds Management Inc.
                       AIM Capital Management, Inc.
                       Invesco National Trust Company
                       PowerShares Capital Management LLC

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      2.   Check the Appropriate Box if a Member of a Group (see
           Instructions)
           (a)
           (b)

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      3.   SEC Use Only  _______________________________________________

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      4.   Citizenship or Place of Organization
           Invesco Ltd.  - Bermuda
                       AIM Advisors, Inc. - US
                       AIM Funds Management Inc. - US
                       AIM Capital Management, Inc. - US
                       Invesco National Trust Company - US
                       PowerShares Capital Management LLC - U.S.


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                               5.  Sole Voting Power 6,299,841: Such
                                   shares are held by the following
                                   entities in the respective amounts
                                   listed:

                                       AIM Advisors, Inc. - 817,400
                                       AIM Funds Management Inc. - 5,308,400
                                       AIM Capital Management, Inc. - 78,072
                                       PowerShares Capital Management LLC - 389

Number of Shares           ----------------------------------------------------
Beneficially Owned
by Each Reporting              6.  Shared Voting Power       -0-
Person With
                           -----------------------------------------------------

                               7.  Sole Dispositive Power 6,309,241: Such
                                   shares are held by the following
                                   entities in the respective amounts
                                   listed:

                                       AIM Advisors, Inc. - 817,400
                                       AIM Funds Management Inc. - 5,308,400
                                       AIM Capital Management, Inc. - 78,072
                                       Invesco National Trust Company - 9,400
                                       PowerShares Capital Management LLC - 389

                           ----------------------------------------------------

                               8.  Shared Dispositive Power    -0-

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          9.   Aggregate Amount Beneficially Owned by Each Reporting Person:

               6,309,241

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          10.  Check if the Aggregate Amount in Row (9) Excludes Certain Shares
               (See Instructions) N/A

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          11.  Percent of Class Represented by Amount in Row (9)  5.15%

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          12.  Type of Reporting Person (See Instructions)
               IA, HC. See Items 2 and 3 of this statement.



                                  SCHEDULE 13G

Item 1(a)     Name of Issuer:

              MDS Inc.

Item 1(b)     Address of Issuer's Principal Executive Offices:

                       100 International Boulevard
                       Toronto, ON M9W 6J6
                       Canada

Item 2(a)     Name of Person Filing:

              Invesco Ltd.

              In accordance with Securities and Exchange Commission Release
              No. 34-39538 (January 12, 1998), this statement on Schedule
              13G or amendment thereto is being filed by Invesco Ltd.
              ("Invesco"), a Bermuda Company, on behalf of itself and its
              subsidiaries listed in Item 4 of the cover of this statement.
              Invesco through such subsidiaries provides investment
              management services to institutional and individual investors
              worldwide.

              Executive officers and directors of Invesco or its
              subsidiaries may beneficially own shares of the securities of
              the issuer to which this statement relates (the "Shares"), and
              such Shares are not reported in this statement. Invesco and
              its subsidiaries disclaim beneficial ownership of Shares
              beneficially owned by any of their executive officers and
              directors. Each of Invesco's direct and indirect subsidiaries
              also disclaim beneficial ownership of Shares beneficially
              owned by Invesco and any other subsidiary.

Item 2(b)     Address of Principal Business Office:

              1360 Peachtree Street NE
              Atlanta, GA 30309
              United States

Item 2(c)     Citizenship:

              See the response to Item 2(a) of this statement.

Item 2(d)     Title of Class of Securities:

              Common Stock, $.01 par value per share

Item 2(e)     CUSIP Number:

              55269P302

Item 3        If this statement is filed pursuant to ss240.13d-1(b) or
              240.13d-2(b) or (c), check whether the person filing is a:

      (e) [x] An investment adviser in accordance with section
              240.13d-1(b)(1)(ii)(E)

      (g) [x] A parent holding company or control person in accordance with
              section 240.13d-1(b)(1)(ii)(G)

              As noted in Item 2 above, Invesco is making this filing on behalf
              of its subsidiaries listed herein. Each of these entities is
              either an investment adviser registered with the United States
              Securities and Exchange Commission under Section 203 of the
              Investment Advisers Act of 1940, as amended, or under similar
              laws of other jurisdictions. Invesco is a holding company.



Item 4        Ownership:

              Please see responses to Items 5-8 on the cover of this statement,
              which are incorporated herein by reference.

Item 5        Ownership of Five Percent or Less of a Class:

              If this statement is being filed to report the fact that as of
              the date hereof the reporting person has ceased to be the
              beneficial owner of more than five percent of the class of
              securities, check the following

              [ ]

Item 6        Ownership of More than Five Percent on Behalf of Another Person:

              N/A

Item 7        Identification and Classification of the Subsidiary Which
              Acquired the Security Being reported on By the Parent Holding
              Company:

              Please see Item 3 of this statement, which is incorporated herein
              by reference.

Item 8        Identification and Classification of Members of the Group:

              N/A

Item 9        Notice of Dissolution of a Group:

              N/A

Item 10       Certification:

              By signing below I certify that, to the best of my knowledge
              and belief, the securities referred to above were acquired and
              are held in the ordinary course of business and were not
              acquired and are not held for the purpose of or with the
              effect of changing or influencing the control of the issuer of
              the securities and were not acquired and are not held in
              connection with or as a participant in any transaction having
              that purpose or effect.

              Signature:

              After reasonable inquiry and to the best of my knowledge and
              belief, I certify that the information set forth in this
              statement is true, complete and correct.

                                                 02/09/2008
                                  --------------------------------------------
                                                   Date

                                  Invesco Ltd.

                                  By: /s/ Lisa Brinkley
                                      ----------------------------------------
                                  Lisa Brinkley
                                  Global Compliance Director