SPECT imaging will be performed according to standard clinical protocols for myocardial perfusion imaging. All patients will undergo SPECT-imaging(Symbia T2, Siemens, The Hague, The Netherlands) on a during hyperaemia induced by infusion of adenosine at a rate of 140mcg/kg/min, using a dose of 400 megabecquerel (MBq) of Technetium (99mTc) tetrofosmin. Tetrofosmin will be administered during adenosine induced stress during the time of the PET stress perfusion scan. Directly after the stress SPECT-sequence, a low dose CT-attenuation scan (CTAC) will be performed. A SPECT- rest imaging scan will be performed 72 hours after the stress SPECT scan on the day of the catheterization.