[单选] 一名52岁的女性接受了氨氯地平和赖诺普利治疗，据推测是原发性高血压，已经治疗了数年。 全科医生看到她抱怨左腰持续疼痛。 她的血压为150/95 mmHg。 她的左腰部柔嫩，两个肾脏都显得肿大。 在尿液试纸测试中，有镜下血尿。 此时，以下哪一项可能是最合适的调查？ A 52-year-old woman has been treated for several years with amlodipine and lisinopril for what has been presumed to be primary hypertension． She is seen by her GP having complained of persistent left loin pain． Her BP is 150/95 mmHg． She is tender in the left loin and both kidneys appear to be enlarged． On urine dipstick testing， there is microscopic haematuria． Which of the following is likely to be the most appropriate investigation at this point？