Ultrasound-guided needle EMG of the diaphragm: technique description and case report.

We describe an ultrasound (US)-guided technique for needle examination of the diaphragm and report a case in which the adjuvant use of diagnostic US in conjunction with electrophysiologic studies provided additional information regarding the motion of the diaphragm in a patient who was a potential candidate for phrenic nerve pacing. US imaging provides excellent direct and real-time visualization of soft tissue, anatomic landmarks, fascial planes, and neurovascular structures. It thereby enhances safety by avoiding accidental needle puncture of vital organs, and it also increases the diagnostic utility of the needle examination.