Given the task definition and input, reply with output. In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Context: Renal ultrasound is very important in the diagnosis of renal tumors.', 'From January 2000 to Jannuary 2005 we retrospectively examined the records of 116 patients, 37 women and 79 men (mean age 54 years, range 22-77), who underwent radical nephrectomy for kidney cancer in clinical stage CT1N0M0. 2.5 cm was the tumor dimension limit between the nephron sparing surgical technique and radical nephrectomy. We subdivided the sample into 2 groups, the first of 45 patients with tumor lesions smaller than 2.5 cm and the second with tumor lesions between 2.5 cm and 7 cm in diameter all patients underwent preoperative staging including ultrasound scan (ETG) and computer tomography scan (CT).', 'Ultrasound has showed 35% sensitivity and 49% specificity for lesions under 2.5 cm in diameter, and 65% sensitivity and 75% specificity and 80% specificity for lesions under 2.5 and 80% sensitivity and 95% specificity for lesions between 2.5 and 7 cm.\Question: Do detection rate of ultrasound vs CT scan in clinical staging accuracy of renal tumors pT1NxMx?
Ultrasound is the first step in the staging of renal cancer before surgery; to assess. 2.5 and 7 in diameter CT scan is the gold standard for solid and cystic lesions.