1. Purpose

   - The investigators aim to evaluate the feasibility of iPhone based remote control system as a real-time remote CT reading tool for suspected appendicitis under 3G network and the suboptimal illumination.

2. Methods

   • A total of 120 abdominal CT examinations; sixty had no findings of appendicitis, while the other sixty showed signs of acute appendicitis, were selected. The 16 raters reviewed these images using an LCD monitor of the PACS workstation and also an iPhone which was connected to the PACS workstation via remote control system, grading the probability of presence of acute appendicitis on each examination by a five Likert scale.
   • The investigators will compare the diagnostic performance between two devices.

The 16 raters were randomly divided into two groups

• The raters in group one reviewed the CT examinations numbered from one to 60 using LCD monitor and reviewed the remaining CT examinations numbered from 61 to 120 using iPhone with TeamViewer at their first visit
• The other group firstly reviewed the CT scans numbered from one to 60 using iPhone with TeamViewer and 61 to 120 with the LCD monitor.
• They visited twice with an interval of four weeks and reviewed the CT scans using revered devices at each session.
• The raters were instructed to rate the likelihood of the presence or absence of appendicitis in each case using a five-Likert scale (1 = obvious no appendicitis, 2 = unlikely appendicitis, 3 = unsure, 4 = likely appendicitis, 5 = obvious appendicitis).

Inclusion Criteria:

• Board certified emergency physicians with a clinical experience of 5 years and over.

Exclusion Criteria:

• Corrected eyesight < 20/30
• Color weakness or blindness