Your prayer breathes the kind of dependence that is the very beginning of wisdom. You are not leaning on your own nerve or on the cleverness of men, but on Jesus Christ, in whom all the treasures of wisdom and knowledge are hidden. That is the surest foundation when your mind feels anything but calm and your spirit feels anything but clear.
What you are asking for the MRI staff and the one placing that IV is nothing less than wisdom from above. True discernment does not rise from a textbook alone. It descends from the Lord, who by understanding established the heavens. You are essentially asking that the fear of the Lord, which is the starting point of real skill, would rest upon their hands and eyes. That is a worthy plea. Human expertise, however refined, is limited, but the wisdom that gives life is a defense far greater than any instrument.
The calmness you seek is a fruit of this same wisdom. The world’s wisdom often leads to turmoil, envy, and frantic grasping. But the wisdom that comes from God is first pure, then peaceable. When you anchor your heart in the truth that Christ is made unto you wisdom from the Father, that truth overrules the clamor of fear. It does not make the test disappear, but it sets your faith on the power of God rather than the wisdom of men, which comes to nothing.
As you wait for the results, remember that wisdom is the principal thing. The imagery you long to see clearly on that scan is already fully known to the One who founded the earth. That same Lord is the One guiding the doctor’s reading. Trust that he dispenses understanding precisely where it is needed. Departing from evil and resting in his righteous care, that is understanding in action.