content: Page 1 of 6 pages
  
                                    UNITED STATES
                         SECURITIES AND EXCHANGE COMMISSION
                               Washington, D.C. 20549
  
  
  
  
                                      FORM 8-K
  
  
  
                                   CURRENT REPORT
  
  
       Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
  
  
  
         Date of Report (date of earliest event reported): December 31, 1997
  
  
  
                             MOLECULAR BIOSYSTEMS, INC.
               (Exact name of registrant as specified in its charter)
  
  
  
                            Delaware 1-10546 36-30878632
                (State or other juris- (Commission file (IRS employer
              diction of incorporation) number) identification number)
  
  
  
                10030 Barnes Canyon Road, San Diego, California 92121
                      (Address of principal executive offices)
  
  
  
         Registrant's telephone number, including area code: (619) 452-0681
  
  
  
  
  
  <PAGE>
  
  
  Item 5.  Other Events.
  
           Approval of OPTISONtm by the FDA
  
           On December 31, 1997, the Company's new drug application for OPTISONtm,
  the Company's  second-generation  contrast agent for cardiac ultrasound imaging,
  was approved by the United States Food and Drug Administration (the "FDA"). This
  approval  permits the  marketing of  OPTISONtm  in the United  States for use in
  patients with  suboptimal  echocardiagrams  to opacify the left ventricle and to
  improve the delineation of the left ventricular endocardial borders.
  
           A copy of the  press  release  that the  Company  jointly  issued  with
  Mallinckrodt,  Inc.,  on January 5, 1998,  is attached to this Report as Exhibit
  10.1.  Mallinckrodt,  Inc., is the Company's  marketing partner for OPTISONtm in
  the United States and most other regions of the world.
  
  
  <PAGE>
  
  
                                    Signature
  
  
             Pursuant to the requirements of the Securities Exchange Act of 1934,
  the registrant has duly caused this report to be signed on its behalf by the
  undersigned  hereunto duly authorized.
  
             Date:   January 20, 1998.
  
  
             Molecular Biosystems, Inc.
  
  
  
             By       /s/ Gerard A. Wills
                      Gerard A. Wills
                      Vice President, Finance
                        and Chief Financial Officer
  
  <PAGE>
  
  
                                   Exhibit Index
  
  
                                                                Sequentially
       Exhibit         Description                              Numbered Page
  
       10.1            Press release (January 5, 1998)                5
metadata_documents: [{"type": "8-K", "sequence": "1", "description": "8-K", "secsgml_size_bytes": 2600}]
metadata_filer: {"company-data": {"conformed-name": "MOLECULAR BIOSYSTEMS INC", "cik": "0000719598", "assigned-sic": "2835", "irs-number": "363078632", "state-of-incorporation": "DE", "fiscal-year-end": "0331"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "001-10546", "film-number": "98509402"}, "business-address": {"street1": "10030 BARNES CANYON RD", "city": "SAN DIEGO", "state": "CA", "zip": "92121-2789", "phone": "6198242200"}, "mail-address": {"street1": "10030 BARNES CANYON ROAD", "city": "SAN DIEGO", "state": "CA", "zip": "92121"}}
text: Page 1 of 6 pages
  
                                    UNITED STATES
                         SECURITIES AND EXCHANGE COMMISSION
                               Washington, D.C. 20549
  
                                      FORM 8-K
  
                                   CURRENT REPORT
  
       Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
  
         Date of Report (date of earliest event reported): December 31, 1997
  
                             MOLECULAR BIOSYSTEMS, INC.
               (Exact name of registrant as specified in its charter)
  
                            Delaware 1-10546 36-30878632
                (State or other juris- (Commission file (IRS employer
              diction of incorporation) number) identification number)
  
                10030 Barnes Canyon Road, San Diego, California 92121
                      (Address of principal executive offices)
  
         Registrant's telephone number, including area code: (619) 452-0681
  Item 5.  Other Events.
  
           Approval of OPTISONtm by the FDA
  
           On December 31, 1997, the Company's new drug application for OPTISONtm,
  the Company's  second-generation  contrast agent for cardiac ultrasound imaging,
  was approved by the United States Food and Drug Administration (the "FDA"). This
  approval  permits the  marketing of  OPTISONtm  in the United  States for use in
  patients with  suboptimal  echocardiagrams  to opacify the left ventricle and to
  improve the delineation of the left ventricular endocardial borders.
  
           A copy of the  press  release  that the  Company  jointly  issued  with
  Mallinckrodt,  Inc.,  on January 5, 1998,  is attached to this Report as Exhibit
  10.1.  Mallinckrodt,  Inc., is the Company's  marketing partner for OPTISONtm in
  the United States and most other regions of the world.
  Signature
  
             Pursuant to the requirements of the Securities Exchange Act of 1934,
  the registrant has duly caused this report to be signed on its behalf by the
  undersigned  hereunto duly authorized.
  
             Date:   January 20, 1998.
  
             Molecular Biosystems, Inc.
  
             By       /s/ Gerard A. Wills
                      Gerard A. Wills
                      Vice President, Finance
                        and Chief Financial Officer
  Exhibit Index
  
                                                                Sequentially
       Exhibit         Description                              Numbered Page
  
       10.1            Press release (January 5, 1998)                5