4

[TLDR: The gradient coils.] That is a great question. There are three parts to an MRI machine: main magnetic field (1.5 Tesla, 3 Tesla etc), gradient coil system and radio-frequency coil. The main magnetic field is static, meaning is doesn't change. Once the technician has "ramped up" the scanner, it will not change. It doesn't get shut down at all. ...


2

Probably the doctor isn't using the stethoscope to determine your heart beat rate. Mine seem to use it to listen to my lungs as I breathe, and I've seen them used to listen for valve sounds or other oddnesses in a baby's heartbeat. The actual rate can be determined other ways: the stethoscope is more for observing the sounds in your chest. They may move on ...


1

Aadrenaline will generally quickly worsen heart failure because it massively increases peripheral vascular resistance and thus after-load on the heart. It significantly increases myocardial oxygen demand and in heart failure due to ischaemic heart disease this can quickly lead to myocardial infarction. Do the effects of epinephrine not last long enough ...


Only top voted, non community-wiki answers of a minimum length are eligible