US Abdomen There are no specific data related to whether a repeat focused RLQ US or a completed abdominal US is more effective in the setting of an initial equivocal US. There are no studies that compare unenhanced and contrast-enhanced CT for diagnosis of acute appendicitis [38,39]. MRI Abdomen and Pelvis MRI performed following equivocal or nondiagnostic appendix US has similar sensitivity and specificity to CT with 100% sensitivity and 96% specificity demonstrated by Herliczek et al [41,71]. In a clinical pathway with US as the initial modality and MRI for problem solving, Epifanio et al [48] demonstrated MRI to add diagnostic benefit in the small subset of cases that remained indeterminate after US. The overall sensitivity and specificity of the described pathway were 96% and 100%, respectively. Importantly, Aspelund et al [72] showed no difference in clinical outcomes following a shift from CT as the primary imaging modality for acute appendicitis to US with MRI for equivocal cases. Regarding perforated appendicitis, Dillman et al [40] showed subsequent MRI to have similar sensitivity and specificity to CT for diagnosis of perforation in patients with an initially equivocal or nondiagnostic RLQ US. It should be noted, however, that the total number of cases of perforation in this study was small (10 in the MR group and 4 in the CT group). Variant 5: Child. Suspected acute appendicitis with clinical suspicion or initial imaging suggestive of complication (eg, abscess, bowel obstruction). Next imaging study. Complicated appendicitis, generally a result of perforation, occurs at a frequency of approximately 30% in the pediatric population and has implications for clinical care [73]. There is debate in the literature regarding optimal care for patients with perforated appendicitis, which can range from antibiotic therapy with delayed appendectomy to interventional drainage to surgical intervention.
Suspected Appendicitis Child. US Abdomen There are no specific data related to whether a repeat focused RLQ US or a completed abdominal US is more effective in the setting of an initial equivocal US. There are no studies that compare unenhanced and contrast-enhanced CT for diagnosis of acute appendicitis [38,39]. MRI Abdomen and Pelvis MRI performed following equivocal or nondiagnostic appendix US has similar sensitivity and specificity to CT with 100% sensitivity and 96% specificity demonstrated by Herliczek et al [41,71]. In a clinical pathway with US as the initial modality and MRI for problem solving, Epifanio et al [48] demonstrated MRI to add diagnostic benefit in the small subset of cases that remained indeterminate after US. The overall sensitivity and specificity of the described pathway were 96% and 100%, respectively. Importantly, Aspelund et al [72] showed no difference in clinical outcomes following a shift from CT as the primary imaging modality for acute appendicitis to US with MRI for equivocal cases. Regarding perforated appendicitis, Dillman et al [40] showed subsequent MRI to have similar sensitivity and specificity to CT for diagnosis of perforation in patients with an initially equivocal or nondiagnostic RLQ US. It should be noted, however, that the total number of cases of perforation in this study was small (10 in the MR group and 4 in the CT group). Variant 5: Child. Suspected acute appendicitis with clinical suspicion or initial imaging suggestive of complication (eg, abscess, bowel obstruction). Next imaging study. Complicated appendicitis, generally a result of perforation, occurs at a frequency of approximately 30% in the pediatric population and has implications for clinical care [73]. There is debate in the literature regarding optimal care for patients with perforated appendicitis, which can range from antibiotic therapy with delayed appendectomy to interventional drainage to surgical intervention.