Depending on the site of interest, the choice of diagnostic procedure (eg, CT, MRI, ultrasonogra- phy) varies, and the selection should be individualized for each patient. The choice of procedure may require consultation with experts. It is strongly recommended that a discussion of which laboratory (microbiology, pathology including cytology) stud- ies will be needed once tissue or fluid aspirate specimens are available takes place before an invasive procedure is performed. Recommendation 1. The choice of diagnostic procedure (eg, CT, MRI, ultrasonography) varies and the selection should be individualized for each patient (Class I; Level of Evidence C). Mycotic Aneurysms MAs are uncommon complications of IE that result from sep- tic embolization of vegetations to the arterial vasa vasorum or the intraluminal space, with subsequent spread of infec- tion through the intima and outward through the vessel wall. Baddour et al Infective Endocarditis in Adults 1471 Arterial branching points favor the impaction of emboli and are the most common sites of development of MAs. MAs caused by IE occur most frequently in the intracranial arteries, followed by the visceral arteries and the arteries of the upper and lower extremities. A detailed analysis of the complex management of MAs has been included in a separate AHA Scientific Statement that addresses vascular infections and is pending publication; please refer to this document for additional information. Intracranial MAs Intracranial MAs (ICMAs) represent a relatively small but extremely dangerous subset of neurological complications. The overall mortality rate among IE patients with ICMAs is 60%. Among patients with unruptured ICMAs, the mortality rate is 30%; in patients with ruptured ICMAs, the mortality rate approaches 80%.315,316 The reported occurrence of ICMAs is probably underestimated because some ICMAs remain asymptomatic and resolve with antimicrobial therapy. 