POWER OF ATTORNEY

Know all by these present, that the undersigned hereby constitutes
and appoints each of William J. O?Shaughnessy, Jr. and Michael E.
Prevoznik, signing singly, his true and lawful attorney-in-fact to:

(1)  execute for and on behalf of the undersigned Forms 3, 4 and 5
in accordance with Section 16(a) of the Securities Exchange Act of
1934 and the rules thereunder;

(2)  do and perform any and all acts for and on behalf of the
undersigned which may be necessary or desirable to complete the
execution of any such Form 3, 4 or 5 and the timely filing of such
form with the United States Securities and Exchange Commission and
any other authority; and

(3)  take any other action of any type whatsoever in connection with
the foregoing which, in the opinion of such attorney-in-fact, may be
of benefit to, in the best interest of, or legally required by, the
undersigned, it being understood that the document executed to this
Power of Attorney shall be in such form and shall contain such terms
and conditions as such attorney-in-fact may approve in his
discretion.

The undersigned hereby grants to each such attorney-in-fact full
power and authority to do and perform all and every act and thing
whatsoever requisite, necessary and proper to be done in the exercise
of any of the rights and powers herein granted, as fully to all
intents and purposes as the undersigned might or could do if personally
present, with full power of substitution or revocation, hereby
ratifying and confirming all that such attorney-in-fact, or such
attorney-in-fact?s substitute or substitutes shall lawfully do or cause
to be done by virtue of this power of attorney and the rights and powers
herein granted.  The undersigned acknowledges that the foregoing
attorneys-in-fact, in serving in such capacity at the request of the
undersigned, are not assuming any of the undersigned?s responsibilities
to comply with Section 16 of the Securities Exchange Act of 1934.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney
to be executed as of this 16th day of May, 2011.


/s/ Mark Guinan
MARK GUINAN

STATE OF NEW JERSEY	)
			) ss.
COUNTY OF MORRIS	)

On this 29th day of July, 2013, before me, Dawn M. Leahy, the
undersigned notary public, personally appeared Mark Guinan,
proved to me on the basis of satisfactory evidence to be the person
whose name is subscribed to the within instrument, and acknowledged to me
that she executed the same for the purposes therein stated.


/s/ Dawn M. Leahy
Notary Public
My Commission Expires: September 12, 2013