The patient is automatically moved head first into the CT gantry, and the x-ray tomogram is acquired. Now the patient is automatically moved through the PET gantry, which is mounted in parallel with the CT gantry, and the PET slices are acquired. The patient may now leave the device, and the PET-CT software starts reconstructing and aligning the PET and CT images.
Diagnostic Procedures. Three common diagnostic procedures, tonometry, visual field tests, and ophthalmoscopy, enable ophthalmologists to screen patients for glaucoma. To make a definitive diagnosis, ophthalmologists often use all 3 procedures as part of an overall eye examination. The procedures are simple, relatively quick, and virtually painless.
Tests for Glaucoma. Glaucoma is detected through a comprehensive eye exam that includes a visual acuity test, visual field test, dilated eye exam, tonometry, and pachymetry. A visual acuity test uses an eye chart test to measure how well you see at various distances.A visual field test measures your side or peripheral vision.It helps your eye care professional tell if you have lost side vision, a sign of glaucoma. Click for more information. In a dilated eye exam, drops are placed in your eyes to widen, or dilate, the pupils.n tonometry, an instrument measures the pressure inside the eye. Numbing drops may be applied to your eye for this test. With pachymetry, a numbing drop is applied to your eye. Your eye care professional uses an ultrasonic wave instrument to measure the thickness of your cornea.