Exhibit 10.1

                                  News Release


FOR IMMEDIATE RELEASE

Molecular Biosystems, Inc.
     Gerard A. Wills, Chief Financial Officer (619) 824-2219
     Stephen F. Keane, Investor Relations (619) 824-2212

US District Court Imposes Status Quo on FDA

         San  Diego,  California  April  22,  1997--Molecular  Biosystems,  Inc.
(NYSE:MB)  (MBI)  responded to the District Court ruling on complaints  filed on
April 14, 1997 by DuPont Merck Pharmaceutical, Inc., ImaRx Pharmaceutical Corp.,
Bracco  Diagnostics,  Inc., and Sonus  Pharmaceuticals,  Inc. against the United
States Food and Drug  Administration  ("FDA")  seeking to compel the FDA to halt
action on MBI's Pre Marketing  Approval  Application  for FS069.  District Court
Judge Paul L.  Friedman  ordered the FDA to preserve  the status quo pending FDA
action on Citizens' Petitions filed with the FDA by the plaintiffs.  On February
24, 1997,  the  Radiology  Device  Advisory  Panel of the FDA voted to recommend
approval of FS069 without conditions.
         The Court's  preliminary  injunction  bars the FDA from approving MBI's
second-generation contrast agent, FS069 and from proceeding with any approval or
review  proceedings  relating to any of the  plaintiffs'  products until 10 days
after the FDA has responded to Citizens' Petitions previously filed with the FDA
by  the  plaintiffs.  The  Citizens'  Petitions  seek  FDA  action  to  regulate
ultrasound   contrast  agents  under  development  by  the  plaintiffs  and  MBI
consistently.  Presently,  MBI is the only company  with an approved  ultrasound
contrast product,  ALBUNEX(R),  which is regulated as a medical device. Products
under development by the petitioners are currently regulated as drugs.
         The Court Order  concluded that the public interest would be "...served
by the grant of a limited  injunction  to  preserve  the  status  quo  pending a
decision by the FDA as to how to treat all ultrasound  contrast agents,  whether
as medical  devices or as drugs,  or to provide a rational  explanation for it's
different treatment of the product as issue here."
         Kenneth J. Widder,  Molecular Biosystems,  chairman and chief executive
officer stated,  "We are disappointed  that the Court has issued this ruling. We
note,  however,  that the Court  sought to  maintain  an even  playing  field by
enjoining  the FDA from  proceeding  with any  approval  or  review  proceedings
relating  to our  competitors'  products.  MBI  believes  that the FDA has acted
correctly in regulating both FS069 and its predecessor product,  ALBUNEX(R),  as
medical  devices.   It  is  unfortunate  that  the  plaintiffs  in  these  court
proceedings  seem  more  interested  in  delaying  the  approval  of  FS069  for
competitive  reasons than in the  interests  of patients  who would  potentially
benefit from the use of this  important new imaging  agent.  MBI's Pre Marketing
Approval Application  demonstrates the safety and efficacy of FS069 under highly
rigorous testing--the same requirements under which the FDA approved ALBUNEX(R),
our pioneering  ultrasound  contrast  agent,  which has been safely used in over
twenty-five thousand patients."
         MBI,  Inc.,  based in San Diego,  California,  is a world leader in the
development and manufacture of ultrasound  contrast devices for medical imaging.
MBI  shares are listed on the New York  Stock  Exchange  under the symbol  "MB".
ALBUNEX(R),  the first FDA  approved  ultrasound  imaging  agent,  is  currently
marketed in the United States by Mallinckrodt Inc.( NYSE:MKG). This news release
contains forward looking  statements that involve risks and  uncertainties.  The
company's  successful  commercialization of FS069 may differ materially from the
company's  expectations.  Among the factors  that could  result in a  materially
different  outcome are the FDA's  decision on the Citizens'  Petitions,  further
review and ruling by the District Court, the actions of regulatory agencies, and
the inherent uncertainty involved in the development of any new product.