LAUSR

Abdominal pain is one of the most frequent and worrisome complaints that brings a patient to the hospital. Patients with undiagnosed abdominal pain usually undergo a battery of investigations, while remaining dissatisfied. Since glucose metabolic imaging with FDG PET has been shown to detect infection, inflammation and malignancies earlier than structural imaging, we planned a pilot study to assess the causes of undiagnosed pain abdomen. The study was carried out at our tertiary care academic institution, from December 2016 to July 2018. A total of 30 patients with no aetiology found on clinical evaluation, laboratory investigations, ultrasound and computerized tomography scan underwent FDG PET CT. PET findings were correlated with clinical parameters to reach a final diagnosis. The results were analysed prospectively to find the utility of PET scan. The mean age was 33.33 years, and 66.67% were females. The number of patients in whom a final diagnosis (relating to pain abdomen) was made with the help of FDG PET was 6; therefore, the yield was calculated as 6/30 = 20.0%. A positive correlation was seen between duration and intensity of pain, raised ESR/positive or borderline Mantoux and presence of findings on PET. The negative predictive value of PET was 100%. Three patients were diagnosed to have tuberculosis, one had aorto-arteritis, one patient had infective foci in lung and one patient had subacute appendicitis. FDG PET scan might be indicated in undiagnosed pain abdomen, especially in patients with chronic pain with raised ESR or positive Mantoux.