Effect of computed tomography of the appendix on treatment of patients and use of hospital resources.

BACKGROUND: In patients with clinically suspected appendicitis, computed tomography (CT) is diagnostically accurate. However, the effect of routine CT of the appendix on the treatment of such patients and the use of hospital resources is unknown. METHODS: We performed appendiceal CT on 100 consecutive patients in the emergency department who, on the basis of history, physical examination, and laboratory results, were to be hospitalized for observation for suspected appendicitis or for urgent appendectomy. Outcomes were determined at surgery and by pathological examination in 59 patients, and by clinical follow-up two months later in 41 patients. Treatment plans made before CT were compared with the patients' actual treatment. We also determined the costs of surgery that revealed no appendicitis (from data on 61 patients), one day of observation in the hospital (from data on 350 patient-days in patients with suspected appendicitis), and appendiceal CT (from data on all pelvic CT examinations in 1996). RESULTS: Fifty-three patients had appendicitis, and 47 did not. The interpretations of the appendiceal CT scans were 98 percent accurate. The results of CT led to changes in the treatment of 59 patients. These changes resulted in the prevention of unnecessary appendectomy in 13 patients, admission to the hospital for observation in 18 patients, admission to the hospital for observation before necessary appendectomy in 21 patients, and admission to the hospital for observation before the diagnosis of other conditions by CT in 11 patients. The effects of performing appendiceal CT on the use of hospital resources included the prevention of unnecessary appendectomy in 13 patients (for a savings of $47,281) and the prevention of unnecessary hospital admission for 50 patient-days (for a savings of $20,250). After the cost of 100 appendiceal CT studies ($22,800) was subtracted, the overall savings was $447 per patient. CONCLUSIONS: Routine appendiceal CT performed in patients who present with suspected appendicitis improves patient care and reduces the use of hospital resources.

Helical CT combined with contrast material administered only through the colon for imaging of suspected appendicitis.

OBJECTIVE: Helical CT combined with contrast material administered by mouth and through the colon has been shown to be accurate for appendiceal imaging. This investigation was performed to determine if helical CT combined with contrast material administered only through the colon has comparable accuracy. SUBJECTS AND METHODS: One hundred patients prospectively underwent appendiceal CT imaging with thin-collimation, helical scanning limited to the lower abdomen and upper pelvis after contrast material was administered only through the colon. CT results were correlated with surgical and pathologic findings at appendectomy (56 patients), other surgery (three patients), or clinical follow-up at least 2 months after the CT scan (41 patients). RESULTS: Fifty-three CT scans were interpreted as positive for appendicitis, including 52 true-positives (with surgical-pathologic correlation) and on false-positive (with clinical follow-up). Forty-seven CT scans were interpreted as negative for appendicitis, including 40 true-negatives with clinical follow-up, three true-negatives with appendectomy and pathologic correlation, three true-negatives with other surgery and pathologic correlation, and one false-negative with appendectomy and pathologic correlation. CT had a 98% sensitivity, 98% specificity, 98% positive predictive value, 98% negative predictive value, and 98% accuracy for diagnosing or excluding appendicitis. In 47 normal appendix cases at CT, the appendix was seen in 44 cases (94%), and an alternative diagnosis was identified in 29 cases (62%). CONCLUSION: For diagnosing appendicitis, helical CT combined with contrast material administered only through the colon proved to be as accurate (98%) as helical CT combined with contrast material administered by mouth and through the colon. Helical CT with contrast material administered only through the colon also could be performed immediately and without any of the potential patient risks or discomforts of contrast material administered i.v. or by mouth.