If after the clinically indicated CCTA a myocardial perfusion examination is indicated, first a single ultra low dose CT scan will be performed to look for late enhancement of potentially scarred myocardium. Together with the contrast agent co-injection of the clinically indicated tracer 99mTc-Tetrofosmin will be performed for later scintigraphic perfusion evaluation. After stress perfusion imaging CT rest perfusion imaging will be performed in a similar fashion. After acquisition of CT rest perfusion images scintigraphic stress and rest image acquisition will be performed as in daily clinical routine with an additional administration of 99mTc-Tetrofosmin resting dose if necessary.