Low-dose Contrast Media for Low-kVp Abdomen CT

Study Overview
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Brief Summary
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The purpose of this clinical study is to test the performance of low radiation dose abdominal CT combined with low dose contrast media for the diagnosis of acute appendicitis in young patients. The main questions to be answered are: 1, Can low-dose contrast media paired with low-dose radiation CT of the abdomen provide acceptable diagnostic accuracy in acute appendicitis? 2. How much radiation dose can be saved by using low radiation dose abdominal CT in combination with low dose contrast media?

Official Title
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Optimizing Low-dose Contrast Media Protocol for Low-kVp Abdominopelvic CT in Suspected Acute Appendicitis

Conditions
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Appendicitis Acute

Intervention / Treatment
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* Diagnostic Test: Weight-adjusted low-dose contrast media paired with low-radiation dose abdomen CT


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: Patients in the emergency department with suspected acute appendicitis based on clinical examination Patients scheduled for contrast-enhanced CT of the abdomen and pelvis for diagnosis of suspected acute appendicitis. Exclusion criteria: Patients who decline to participate Contraindications to contrast-enhanced CT (eGFR < 30 mL/min/173 m^2 or pregnant) BMI >= 30.

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 44 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Double low-dose CT<br>Weight-adjusted low-dose contrast media paired with low-radiation dose abdomen CT | Diagnostic Test: Weight-adjusted low-dose contrast media paired with low-radiation dose abdomen CT<br>* The investigators are aiming for a 10% reduction in iodine dosage at 10 kVp reduction in CT radiation. Routine iodine dosing is 0.521 g I/kg at 120 kVp. Therefore, at 90 kVp, a 30% reduction in iodine dosing is expected, which is 0.365 g I/kg. At 100 kVp, the iodine dosage is reduced to 0.417 g I/kg, which is a 20% reduction. The kVp value is automatically selected by the CT device according to the body habitus, which is a clinical routine.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diagnostic accuracy for acute appendicitis | The primary outcome of the study is the diagnostic accuracy of double low-dose CT for acute appendicitis in young adults with suspected acute appendicitis. Based on the CT findings, a three-tiered diagnosis of appendicitis will be given (no appendicitis, uncomplicated appendicitis, or complicated appendicitis). In the case of no appendicitis, a possible alternative diagnosis is given. The reference standard for appendicitis is operative findings and surgical pathology reports. In nonoperative cases, sequential radiologic evaluation, clinical follow-up, and the judgment of the attending physician will conclude the diagnosis. Specifically, if the patient is not treated for recurrent symptoms within 6 months, the radiologic diagnosis of CT findings is considered valid. The diagnostic accuracy for acute appendicitis is true positive for acute appendicitis and true negative for acute appendicitis divided by all participants. | For operated patients, postop. period (up to 1 month); If non-operated, at 6 months-FU | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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acute appendicitis, acute abdomen, CT