In nature, methane is produced by the anaerobic bacterial decomposition of vegetable matter under water (where it is sometimes called marsh gas or swamp gas). Wetlands are the major natural source of methane produced in this way.
What are the exams and tests for renal artery stenosis? Blood tests. Screening blood tests may be done as part of the general evaluation of high blood pressure and may include a complete blood count, electrolytes, kidney function tests, and a urinalysis. Imaging. Renal artery narrowing can be detected with ultrasound or computerized tomography angiography or arteriography.
Why It Is Done. A kidney scan is done to: 1  Check the blood flow through the kidneys. 2  Abnormal flow may mean narrowed renal arteries that can cause a type of high blood pressure called renovascular hypertension. 3  See how a transplanted kidney is working. 4  Check the extent of kidney damage caused by an injury or infection.