Cell membranes are semi-permeable. Just like your private dinner party, only certain molecules can cross the cell membrane. This allows the cell some control over what enters and leaves. Water, small molecules, and molecules without a charge can pass freely.
Magnetic Resonance Angiography (MRA) and Magnetic Resonance Venography (MRV) Aetna considers magnetic resonance angiography (MRA) medically necessary according to the selection criteria outlined below. MRA is considered appropriate when it can replace a more invasive test (e.g., contrast angiography) and reduce risk for members. While MRA is a rapidly evolving technology, its clinical safety and effectiveness for all anatomical regions have not been established by the peer- reviewed medical literature.
There are two tests used for cervical cancer screening: the Pap test and the HPV test. The Pap test (also known as the Pap smear) is a simple and effective way of checking cells from your cervix to see if they are normal or abnormal. Some abnormal cells can develop into cancer. The HPV test is used to look for human papillomavirus (HPV) in the cells from your cervix. HPV is the cause of cervical cancer.