The Optimization of a Low-dose Computed Tomography Protocol in Patients With Suspected Uncomplicated Acute Appendicitis
The Optimization of a Low-dose Computed Tomography Protocol in Patients With Suspected Uncomplicated Acute Appendicitis
This study focuses on the use of contrast enhanced low-dose CT imaging as a modality to
 differentiate between uncomplicated and complicated acute appendicitis. Differentiation
 between the two forms of acute appendicitis is important because according to recent studies
 their treatment differs. Complicated forms are still treated operatively, while uncomplicated
 forms can be treated conservatively with antibiotics. In the initial phase of the study,
 several optimized CT protocols will be created with a phantom model. The two best performing
 models will be selected for the second phase of the study, in which patients presenting with
 suspected acute appendicitis will be imaged with the two protocols. All patients
 participating in the study will be treated operatively, primarily with a laparoscopic
 appendectomy. Thus histological confirmation for the diagnosis can be achieved and compared
 with the CT images. The goal of this study is to optimize a well-performing low-dose CT
 imaging protocol to use in the diagnosis of uncomplicated acute appendicitis.
Acute appendicitis is one of the most common causes of abdominal pain in emergency
 departments as well as one of the most common indications for emergency abdominal surgery.
 The clinical diagnosis has been based on patient history, physical examination and laboratory
 findings as well as the "clinical eye" of the surgeon. Still the diagnosis remains
 challenging. One of the main problems is that many other disorders can mimic the clinical
 presentation of appendicitis, thus increasing the role of imaging techniques to aid in
 diagnostic accuracy. Now preoperative imaging in patients with suspected acute appendicitis
 is currently widely accepted as the standard of practice, and CT has been shown to clearly
 outperform US in terms of diagnostic performance. Nowadays, CT imaging is considered the
 primary imaging modality in the diagnosis for acute appendicitis as it is appraised for its
 high sensitivity and specificity. The main disadvantage of CT imaging is exposure to
 radiation. Thus the favorable diagnostic performance of CT imaging has encouraged
 optimization of protocols to minimize exposure to radiation through the development of
 low-dose CT protocols. Initial studies have indicated that contrast enhanced low-dose CT was
 not inferior to standard-dose contrast enhanced CT with no statistical significance in
 negative appendectomy rates, appendiceal perforation rates or patients requiring additional
 imaging.

 This study focuses on the use of contrast enhanced low-dose CT imaging as a modality to
 differentiate between uncomplicated and complicated acute appendicitis. Differentiation
 between the two forms of acute appendicitis is important because according to recent studies
 their treatment differs. Complicated forms are still treated operatively, while uncomplicated
 forms can be treated conservatively with antibiotics. In the initial phase of the study,
 several optimized CT protocols will be created with a phantom model. The two best performing
 models will be selected for the second phase of the study, in which patients presenting with
 suspected acute appendicitis will be imaged with the two protocols. All patients
 participating in the study will be treated operatively, primarily with a laparoscopic
 appendectomy. Thus histological confirmation for the diagnosis can be achieved and compared
 with the CT images. The goal of this study is to optimize a well-performing low-dose CT
 imaging protocol to use in the diagnosis of uncomplicated acute appendicitis.
Inclusion Criteria:

 -  Age 18-60 years

 -  Clinical suspicion of acute uncomplicated appendicitis based on history, physical
 examination, laboratory findings evaluated by a senior surgeon

 Exclusion Criteria:

 -  Age <18 years or > 60 years

 -  Pregnancy or breastfeeding

 -  Allergy to contrast material or iodine

 -  History of appendectomy

 -  Renal failure, creatinine-value greater than the upper reference value

 -  Diabetes mellitus and metformin medication

 -  Suspicion of peritonitis and appendiceal perforation

 -  Incapability to cooperate and give consent to participate in the study

 -  A severe generalized disease or condition