To detect an aorta aneurism,can an ultrasound be enough?if not,can an mri "without contrast material" be accurate enough to detect an aorta aneurism?

See below: An ultrasound will detect most abdominal aortic aneurysms if it's technically good (i.e. no overlying bowel gas). The radiologist will generally comment on the quality of the study. An echocardiogram can generally detect a thoracic aortic aneurysm. A CT angiogram can reliably detect either but there is a radiation dose. A non-contrast MRI isn't the test of choice.