Pelvic US may identify other causes of pain in girls but there are no data regarding its performance as a first-line imaging modality for acute appendicitis [52]. CT Abdomen and Pelvis In a retrospective study of children who underwent CT of the abdomen and pelvis for suspected acute appendicitis, Kim et al [50] found that no patient categorized as low risk by the Pediatric Appendicitis Score had a positive CT. Similarly, based on retrospective study of a mixed population of children and adults who underwent CT, McKay and Shepard [53] showed that the Alvarado score could rule out appendicitis in low-risk patients with 96% sensitivity. Alternative causes of abdominopelvic pain, which have been described to occur at rates between 7% and 25%, may be identified by CT [54,55]. There are no studies that compare unenhanced and contrast-enhanced CT for diagnosis of acute appendicitis [38,39]. MRI Abdomen and Pelvis Most studies have shown that in patients stratified as low risk (which varies per study and is based on the system used), imaging for acute appendicitis is not required, and other causes of abdominopelvic pain should be sought [13,16,17,48-50]. Alternative causes of abdominopelvic pain, which occurred at a rate of 20% in a study of MRI as the primary imaging modality for suspected acute appendicitis, may be identified by MRI [55]. Radiography Abdomen Radiographs are neither sensitive nor specific for the diagnosis of acute appendicitis but may identify alternative causes of pain [51]. US Abdomen There are no specific data regarding the relative performance of a focused RLQ US versus a complete abdominal US in intermediate-risk patients. US Pelvis There are no data specific to the use of pelvic US only in children with intermediate clinical risk for acute appendicitis. Pelvic US may be part of a complete evaluation for abdominopelvic pain in peri- or postmenarchal girls [52].
Suspected Appendicitis Child. Pelvic US may identify other causes of pain in girls but there are no data regarding its performance as a first-line imaging modality for acute appendicitis [52]. CT Abdomen and Pelvis In a retrospective study of children who underwent CT of the abdomen and pelvis for suspected acute appendicitis, Kim et al [50] found that no patient categorized as low risk by the Pediatric Appendicitis Score had a positive CT. Similarly, based on retrospective study of a mixed population of children and adults who underwent CT, McKay and Shepard [53] showed that the Alvarado score could rule out appendicitis in low-risk patients with 96% sensitivity. Alternative causes of abdominopelvic pain, which have been described to occur at rates between 7% and 25%, may be identified by CT [54,55]. There are no studies that compare unenhanced and contrast-enhanced CT for diagnosis of acute appendicitis [38,39]. MRI Abdomen and Pelvis Most studies have shown that in patients stratified as low risk (which varies per study and is based on the system used), imaging for acute appendicitis is not required, and other causes of abdominopelvic pain should be sought [13,16,17,48-50]. Alternative causes of abdominopelvic pain, which occurred at a rate of 20% in a study of MRI as the primary imaging modality for suspected acute appendicitis, may be identified by MRI [55]. Radiography Abdomen Radiographs are neither sensitive nor specific for the diagnosis of acute appendicitis but may identify alternative causes of pain [51]. US Abdomen There are no specific data regarding the relative performance of a focused RLQ US versus a complete abdominal US in intermediate-risk patients. US Pelvis There are no data specific to the use of pelvic US only in children with intermediate clinical risk for acute appendicitis. Pelvic US may be part of a complete evaluation for abdominopelvic pain in peri- or postmenarchal girls [52].