If you haven't already:
Select the patient.
Click Write (ALT+W).
Click Diagnostic Studies (ALT+I).
ECG/EKG
Echocardiogram
Holter: Holter monitoring can only be ordered as an outpatient study through the ambulatory Holter Lab
EEG
EMG (Nerve Conduction Studies)
Evoked Potential
Sleep Studies
PFTs
Noninvasive Vascular Studies