POWER OF ATTORNEY
Know all by these presents, that the undersigned hereby authorizes Nicholas A. 
Poan and Leigh Ann Clifford of Alliance HealthCare Services, Inc. (the 
"Company"), and each of them individually to execute for and on behalf of the 
undersigned, in the undersigned's capacity as an officer of the Company, Forms 
3, 4 and 5, and any amendments thereto, and cause such form(s) to be filed with 
the U.S. Securities and Exchange Commission (the "SEC") pursuant to Section 
16(a) of the Securities Act of 1934, as amended (the "1934 Act") relating to the 
undersigned's beneficial ownership of securities in the Company. The undersigned 
hereby grants to each such attorney-in-fact full power and authority to do and 
perform any and every act and thing whatsoever requisite, necessary, or 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 each such attorney-in-fact, or each 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, 
nor is the Company assuming, any of the undersigned's responsibilities to comply 
with Section 16 of the 1934 Act.
This Power of Attorney shall remain in full force and effect until the 
undersigned is no longer required to file Forms 3, 4 and 5 with respect to the 
undersigned's holdings of, and transactions in, securities issued by the 
Company, unless earlier revoked by the undersigned in a signed writing delivered 
to the foregoing attorneys-in-fact.
In Witness Whereof, the undersigned has caused this Power of Attorney to be 
executed as of this 31st day of January 2012. 
/s/
_____________________
Richard W. Johns
Alliance HealthCare Services, Inc 4
