Cerebral Diagnostic Catheter for All Ages Diagnostic catheter angiography has been long essential for the diagnosis of moyamoya disease. However, catheter angiography itself is not 100% safe with inherent low rate of complications. Today, magnetic resonance imaging and angiography play a major role in the diagnosis of moyamoya disease. In Pediatric cases, MRI and MRA are the first line diagnostic modalities instead of catheter angiography. In general, catheter angiography uses a small tube called catheter, which is inserted into the femoral artery under local anesthesia (for children, general anesthesia is used). Outer diameter of the catheter is usually 4 or 5 French size (1.3-1.6 mm). In side the catheter, a guidewire (0.035-0.038 inch) is used for the navigation of the catheter. [3 French = 1 mm]. In practice, for the introduction of the catheter, a vascular sheath is used for the insertion of the catheter. Thus, a real hole made at the femoral artery depends upon the outer diameter of the vascular sheath. The outer diameter of vascular sheath for a 5 French catheter is usually 6.6-6.8 French (2.2-2.3 mm). We use small 3.2 French diagnostic catheter, for which the outer diameter of the vascular sheath is 4.7 French (now 4.0 French)(1.6-1.3 mm). Due to reduced outer diameter of the vascular sheath from 2.3 to 1.3 mm, we use this catheter system both for children and adults. This system allows a short bed-rest for 3 hours. After 3 hours, the patients are allowed to walk. This less invasive examination is suitable for moyamoya disease for either pediatric or adult patients. References 1. Komiyama M, Yamanaka K, Nishikawa M, Izumi T: Prospective analysis of complications of catheter cerebral angiography in the digital subtraction angiography and magnetic resonance era. Neurol Med Chir (Tokyo) 38: 534-540, 1998 [abstract] 2. Komiyama M, Nakajima H, Nishikawa M, Yamanaka K, Iwai Y, Yasui T: A 3.2-F cerebral diagnostic catheter for all ages: technical note. AJNR 22: 1602-1603, 2001 [abstract]