Exhibit 10.10
February 1, 1995



Ronald G. Evens, M.D.
The Edward Mallinckrodt Institute of Radiology
516 S. Kingshighway
St. Louis, MO 63110

Dear Dr. Evens:

A letter of agreement dated December 22, 1986 and renewal letters
dated November 29, 1989, February 19, 1991, January 16, 1992, December
17, 1992, and January 7, 1994, between you and Mallinckrodt Medical,
Inc. set forth the general terms and conditions under which you agree
to serve Mallinckrodt Medical, Inc., in a consulting capacity for the
period beginning January 1, 1987 and ending December 31, 1994.

Mallinckrodt Medical Inc. desires to retain your consulting services
through the period beginning January 1, 1995 and ending December 31,
1995 under the same terms and conditions as set forth in said letter
agreement dated December 22,1986 and renewal letters dated November
29, 1989 and February 19, 1991.

If the foregoing meets with your understanding and approval, please
execute this letter in duplicate at the place indicated below and
return one of the signed duplicates to us thereby indicating your
agreement to continue to serve Mallinckrodt Medical, Inc., as a
consultant for the above-stated period.

Very truly yours,                     ACCEPTED & AGREED TO:

MALLINCKRODT MEDICAL, INC.            RONALD G. EVENS, M.D.

BY:    J. EUGENE FOX                       RONALD G. EVENS, M.D.
- --------------------------            ------------------------------
       J. Eugene Fox                       Ronald G. Evens, M.D.

Title: Senior Vice President          
       Science and Technology

DATE:   February 6, 1995